* GB785608 (A)

Description: GB785608 (A) ? 1957-10-30

Improvements in flushing tanks for water closets and the like

Description of GB785608 (A)

PATENT SPECIFICATION 785 608 Date of Application and filing Complete Specification: May II, 1954. No 13721/54. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 26, H 1 E 1 (A: C: F), H 1 E 2 (B: F: M). International Classification:-E 03 d. COMPLETE SPECIFICATION Improvements in Flushing Tanks for Water Closets and the like I, JOSEF VYMER, of 2 Komsomolsk A, Praha XIX, Czechoslovakia, a Czechoslovak citizen, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement: - The present invention relates to flushing devices for use with water closets and in similar localities. It is the object of the present invention to devise such a device which is simple in its construction and' therefore reliable in operation, and which, as a result of the simple configuration of the individual parts, can be manufactured from synthetic materials which are not susceptible to corrosion and are easy to shape. To this end the flushing device according to the invention comprises a tank, a trap tube which extends through a hole in the bottom wall of the tank which tube is closed at its lower end and projects with its open upper end a certain distance into the tank above the bottom wall thereof, a discharge pipe which passes through the lower end wall of the said trap tube and extends co-axially into the interior of the trap tube, a syphon tube which a's open at the lower end, and closed at its upper end and, which is co-axially disposed in the annular space between the trap tube and the discharge pipe in such a manner

that the open end is a certain distance above the lower end wall of the trap tube and the closed end is a certain distance above the end of the discharge pipe, a movable bell which, in its normal position, covers the upper end of the said tubes -andl is so shaped that, its rim surrounds the projecting end of the trap tube and a passage for the water past the rim, is formed, and a float connected to or made integral with the said bell, and the arrangement is made such that the height of the discharge tube within the said syphon tube, reckoned from the lower end of the syphon tube, is somewhat greater than the height of the intended highest water level in the tank above the top of the trap tube. As a result of this construction, an air trap is formed in the annular space between the trap tube and the syphon tube which, in connection 50 with a water column formed in the annular space between the syphon tube and the discharge tube, prevents a discharge of water from' the tank as long as the air is prevented from escaping by the closed bell When water 55 is admitted into the tank and the so produced buoyancy 'of the belll causes the latter to rise the bell allows the air to escape from the trap tube so that the water from the tank is free to enter the trap tube and it continues to flow 60 through the syphon tube into the discharge pipe In this way an automatic intermittent discharge of the water is obtained. Conveniently, the float extends above the highest intended level of the water in the tank 65 and has a cross-sectional area smaller than, that of the bell The float may 'be left open at the top, and this has the advantage that the weight of the float may be adjusted by placing into its cavity some ballast material, such as 70 sand or lead shot, and this simple adjustment of the weight of the float results in an adjustment of the height of the water level in the tank at which the bell rises and allows the discharge 75 In order that the invention may 'be clearly understood it will now be described with reference to the accompanying drawings, wherein Fig 1 shows a section through the flushing tank for automatic intermittent opera 80 tion, whilst Fig 2 shows the same construction of the flushing tank but adapted for manual operation. As shown, the flushing device has a tank 1 which has an aperture 'in its bottom wall A 85 trap tube 2, which is open at the top and closed at the bottom, extends through this aperture so that its upper rim 3 projects a certain distance into the tank l The bottom wall 4 of the trap tube 2 has a centrally dis 90 posed aperture through which a discharge pipe 6 extends, which discharge pipe 6 is co-axially disposed with respect to the trap tube 2 A smaller lateral bore is provided in the bottom wall 4 of the trap tube which contains a nor 95 mally closed valve 5 which serves for cleaning purposes Another tube 8

is provided which extends co-axially into the annular space between the trap tube and the discharge tube, subdividing this annular space into two concentric annular spaces 20 and 21 The tube 8 is open at its lower end and ends a certain distance above the bottom wall 4 of the trap tube 2; its upper end is closed a certain distance above the upper open end of the discharge tube The tube 8 is secured by ribs 7 radially protecting from the outer wall of the discharge tube 6 and secured to its inner surface The tube 8 thus forms with the discharge tube '6 a syphon system In order to reduce the resistance to flow, the central portion of the upper closing wall of the syphon tube 8 is thickened to deflect gradually the stream of water flowing into the discharge tube as will be described hereinafter. The described syphon tube system is covered, by a bell 10, which is formed by a hollow cylinder which is closed at the top by a transverse wall 11 and which is widened at the lower end by forming a horizontally extending flange 14 merging into a downwards extending rim 13 which surrounds at a certain distance the upwardly projecting rim 3 of the trap tube 2 The bell rests on the top of the syphon tube 8, and in order to prevent the wall 11 and the top wall of the syphon tube 8 from sticking together the top wall is provided also at its upper face with a thickening 9 to produce a small-area contact The arrangement is made such that, when the bell 10 rests on the top wall of the syphon tube 8 its lower rim 13 is at a small distance from the bottom wall of the tank 1. The cylindrical wall of the bell is extended in an upward direction so that its upper open end lies above the liquid level under all operational conditions This upward extending portion 12 of the bell forms a float, and it is adapted to receive a ballast 18, e g sand or lead shot, to adjust the buoyancy of the float. The bell and float are shown to form an integral unit but both members could be manufactured, separately and connected, together. The bell with its float are secured to the end of a lever 15 which is pivotally mounted at its other end about a pivot pin 16 near a side wall of the tank 1, and this end of the lever is provided with a projection 17 which coacts with the side wall of the tank so as to limit the rocking movement of the lever 15. However, the said projection can also be omitted since the amplitude of the rising movement of the bell and its float js in fact determined, by the height of the water level in the tank Fig 1 of the drawings shows the elevated position of the bell and float by dotted lines. The water is supplied into the tank 1 through a pipe controlled by a valve 19. The described device operates as follows:

When the tank 1 is empty and water is supplied at a constant rate adjusted by the valve 19, the water will penetrate through the gap between the lower rim 13 of the bell and, the bottom of the tank into the space below the bell, and when ithe water level has 70 risen above the rim 3 of the trap tube 2, the water will flow over this rim and collect at the bottom of the trap tube 2, and, after reaching the lower end of the syphon tube, the water seals the annular space 20 between the syphon 75 tube 8 and the trap tube 2 and traps in this manner the air contained' within this space. The water continues to rise in the tank, and part of the water flows over the rim 3 of the trap tube 2 and, rises also in the annular space 80 21 ' between the syphon tube 8 and the discharge tube 6, and the height H of the water in the tank, reckoned from the rim 3 to the upper water level, will be the same as the height of the water within the said annular 85 space 21, reckoned from the water level in the annular space 20 up tto the water level in the annular space 21 Since 'the level in space rises slightly above the bottom of the syphon tube 8, it will be appreciated that the 90 axial extension of the annular space 21 must be greater than the desired height H of the water in the tank 1, otherwise water would continuously flow from the space 21 into the discharge pipe 6 and escape through this pipe 95 With the rising water level in the tank 1, the buoyancy of the 'bell and float increases and eventually a state of equilibrium between the weight of the bell and float and the buoyancy of these members is reached When 100 now the height of the water level further increases the said equilibrium is destroyed and the bell and float begins 'to rise, first slowly and, then with great speed. Thus the bell and float moves vigorously 105 towards the position shown by dotted lines in Fig, 1, until the air is free to escape from the space 20, whereby the air seal is removed and the water is allowed' to flow down through the annular space 20 and then up through the 110 annular space 21 and down again through the discharge tube 6 The bell and float moves downwards as the water level in the tank drops and at the end of 'the discharge the water from the space 20 is withdrawn as a result of 115 the syphon effect of the syphon tube 8 and the discharge tube 6, so that air enters the space 20 from the empty tank and this air is trapped again by the continued water supply as hereinbefore described' 120 This cycle continuously repeats and an automatic intermittent discharge of the water is obtained. It will be appreciated that by changing the rate of the water supply by means of the valve 125 19 the interval between the individual discharge actions can be adjusted, whilst the quantity of the discharged water, i e the level H of the water just before the discharge, can be adjusted by increasing or reducing the bal 130

785,605 at the lower end and closed at its upper end 60 and which is co-axially disposed in the annular space between the trap tube and the discharge pipe in such a manner that the open end is a certain distance above the lower end wall of the trap tube and the closed end is 65 a certain distance above the end of the discharge pipe, a movable bell which in its normal position, covers the upper end of the said tubes and, is so shaped that, its rim surrounds the projecting end of the trap tube 70 and a passage for the water past the rim is formed, and a float connected to or made integral with the said bell, and wherein the arrangement is made such that the height of the discharge tube within the said syphon 75 tube, reckoned from the lower end of the syphon tube, is somewhat greater than the height of the intended highest water level in the tank, above the top of the trap tube. 2 Flushing device according to claim 1, 80 wherein the float extends above the highest intended level of the water in the tank and has a cross-sectional area smaller than that of the bell. 3 A flushing device according to claim 2, 85 wherein the float is open at the top. 4 A flushing device according to any of the preceding claims wherein the bell has an upper cylindrical portion closed at the top 'by a transverse wall and provided at the lower 90 end with a flange-like widening which merges into a lower cylindrical portion of larger diameter than the said, upper portion, which lower portion ends a short distance from the bottom of the tank, when the said transverse 95 wall rests on the upper closed end of the said syphon tube. A flushing device according to any of the preceding claims, wherein the bell and float is fastened to a lever which is pivotally 100 mounted in the tank. 6 A flushing device, according to any of the preceding claims, wherein a tripping lever is provided for holding the bell and float in its normal position, which tripping lever is 105 adapted to 'be operated; by hand for the release of the bell and float, and wherein an additional float is provided for the control of the water supply into the tank. 7 Flushing devices substantially as de 110 scribed with reference to and as illustrated in the accompanying drawings. For the Applicants: MATTHEWS, HADDAN & CO, Chartered Patent Agents, 31-32, Bedford Street, Strand, London, W 1 C 2. last 12, i e the weight of the bell and float. Thus, the operation of the flushing tank can be adjusted in a simple manner. It is possible, of course, to adapt the flushing tank shown in Fig, 1

for manual operation For this purpose a device is required to maintain the bell and float in their lowermost position, and, another device for shutting off the water supply when the water has risen in the tank 1 to a certain height, which height must be to some extent higher than the height H at which the automatic operation of the device is initiated The required additional devices are shown in Fig 2 by dotted lines. A detent lever 24 is pivotally mounted and engages with its lower end the flange 14 of the bell 10 and has at the top a shorter horizontally extending arm which is engaged by a tripping lever 22 pivotally mounted about a pivot pin 23 and adapted to be operated by a chain 25 The supply pipe 28 for the water is provided with a valve 26 adapted to be actuated by a float 27 Thus, when the chain is pulled downwards, the tripping lever 22 is rocked about the pivot pin 23 and turns the lever 24 and allows thereby the bell and float to rise so that the water discharges In the course of the discharge of the water the bell and float returns into the position' shown, and the released detent lever 24 engages again the bell and float to hold it in the closed position Also the float 27 dropped during the discharge of the water and opened, the water supply valve 26 so that an additional quantity of water is supplied into the tank, When the water reaches a certain level at which the buoyancy of the bell and float is appreciably higher than its weight, the float 27 closes the supply valve 26. It will 'be appreciated that the flushing device described is built up of parts which have a very simple configuration; they consist of substantially straight 'tubular members and are therefore capable of being manufactured in a simple manner Therefore they can be made from any suitable synthetic material which does not rust as iron does and which is resistant to corrosion.

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* GB785609 (A)

Description: GB785609 (A) ? 1957-10-30

Method for the production of pure silicon

Description of GB785609 (A)

PATENT SPECIFICATION 785609 Date of Applic No 16842/54. Complete Spec oation and filing Complete Specification: June 8, 1954. ification Published: Oct 30, 1957. Index at acceptance:-Class 90, K 10. International Classification:-C Olb. COMPLETE SPECIFICATION Method for the Production of Pure Silicon I, JORGEN AUGUST KOLFLAATEI, of Hielmsgate 7, Oslo, Norway, a Norwegian subject, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement: - The present invention relates to a process for the production of high grade silicon by acid leaching of 75-97 % ferrosilicon. Increasing use is being made of high grade silicon in the production of silicon containing light metallic alloys, as for example silumin; and the " intermediates " in the manufacture of silicon-containing resins, the silicones. Great demands are made, however, on the silicon thus employed with respect to purity, as the presence of even small amounts of impurities may change the properties of the alloys in an unfavorable manner. Commercial 90 % Fe-Si is commonly produced in electric furnaces from coke and quartz with the continuously working Soderberg electrode The silicon content of the product differs from one day to another due to segregation within the furnace; the amounts of impurities in the quartz and coke; and the contamination by iron from the iron-rods commonly used for the discharge of the furnace. Table 1 shows the composition of commercial 901 %y Fe-Si from a Swedish producer of ferro-silicon over a period of 10 years, Table 2 over a period of 13 days, and Table 3 over a period of 2 days. The most common method of producing commercial 96-99 % silicon "metal," consists in reducing 99 6-99 8 % crystal quartz with charcoal in an electric furnace provided with graphite electrodes The silicon content of the product differs from one day to another, due to different amounts of impurities in the quartz and charcoal, and segregation within the furnace. Table 4 shows the composition of silicon metal produced by the

charcoal process over a period of 3 days, Table 5 over a period of 8 days and Table 6 over a period of 4 days. TABLE 1. (%age by weight) (Jirnkontorets Forskninger," No 190 Vol. 17, p 802 1953 Sweden). Commercial 90 % Fe-Si Average Si = 85 5 92 6 % 90 7 % C = 0 10 0 34 % 0 16 % Mn= 0 02 0 21 % 0 05 % P = 0 010 O 034 % 0 023 % S = 0 003 0 020 % 0 008 % Al = 11 8 3 51 % 2 4 % Fe = 3 4 9 5 % 5 5 % TABLE 2. (%age by weight) May,%C % Si % Fe %Al 7 9 11 12 13 1 '5 18 88.4 90.6 91.3 0.12 91 6 91.7 92.0 90.9 0.05 92 9 0.07 93 2 7.5 2 53 5.0 3 30 4.5 2 93 4.8 2 42 4.2 2 87 4.4 2 44 5.2 2 70 3.5 2 39 3.6 1 94 785,609 TABLE 3. (%age by weight) Sept Melt No % C %Si % AI % Ti % Fe 8 200 0 03 94 0 2 18 0 19 3 0 201 0 06 92 7 1 62 4 7 202 0 03 92 8 2 46 0 20 3 7 203 0 06 93 6 2 08 3 5 204 0 03 94 7 1 28 3 2 205 0 03 92 6 2 04 0 21 4 2 206 0 04 91 5 1 86 5 6 207 0 06 94 6 1 70 0 18 2 6 9 208 0 05 94 2 2 10 2 8 TABLE 4. (%age by weight) February %C % Si % Fe % Al % Ca 27 27 28 March 0.16 94 O 0.08 96 5 0.04 98 1 1.40 1.04 0.67 2.80 1.63 0.76 0.99 0.54 0.26 0.08 96 8 0 73 IS 1.40 0 75 TABLE 5 Sept C 22 0 04 23 0 09 24 0 07 26 0 06 27 0 07 0 08 0 09 0 09 0 07 si 95.3 96.2 97.1 97.3 97.4 97.2 96.6 95.7 98.0 Mn P 0.03 0 008 0.03 0 006 0.025 0 005 0.022 0 006 0.021 0 006 0.018 0 007 0.022 0 010 0.030 0 006 0.015 0 004 (%age by weight) S Fe trace 2 56 ,1 1 83 ,1 1 12 ,3 0 76 1 j, 0 67 0.92 , 1 07 , 1 96 ,3 0 65 Al 0.96 0.77 0.66 0.73 0.75 0.61 0.80 0.95 0.39 Ti Ca 0.037 0 79 0.045 0 83 0.036 0 68 0.031 0 91 0.028 0 83 0.028 0 84 0.053 1 09 0.031 0 93 0.025 0 64 Mg Weight % kg 0.061 7674 0.045 9294 0.10 13812 0.033 8675 0.030 9150 0.067 12542 0.048 11017 0.059 7249 0.066 10461 00 -A 0 m 4 785,609 TABLE 6. (%age by weight) Melt Melt March No % Si March No % Si 11 126 127 128 129 131 12 132 133 134 136 137 138 139 141 142 143 97.9 97.6 95.8 96.6 97.3 97.7 97.8 97.5 98.1 97.8 98.2 97.7 98.5 97.8 98.0 98.6 98.2 98.0 The cost of producing 90 % Fe-Si amounts to about half the cost of producing the same quantity by weight of commercial 96-99 % silicon metal by the charcoal process, in spite of the fact that the latter product only contains on an average 6 % more silicon The reason is principally due to the difference between the costs of coke and charcoal; on the other hand the saving in using quartz in lieu of crystal quartz and Soderberg electrodes in lieu of graphite electrodes is of minor importance. Silicon containing 95-97 % Si may be produced by substituting some of the charcoal in the quartz-charcoal mixture by coke, this quality of silicon, however, being of minor commercial importance. The great difference in production costs between commercial 90 % Fe-Si

and silicon metal constituted my starting point in the evaluation of a method for add leaching of commercial 90 % Fe-Si to silicon metal. It is well known to the art that ferrosilicon containing more than 65 % Si may be refined to silicon metal by extraction with hydrofluoric acid Thus, Union Carbide, among others, produces 99 7-99 9 % "refined silicon metal " on a large scale by leaching 95-97 % Si with hydrofluoric acid. Hydrofluoric acid, however, is a rather expensive and dangerous acid, and calculations show that hydrofluoric acid leaching of the relatively cheap commercial 90 % Fe-Si is less economical than hydrofluoric acid leaching of the relatively expensive commercial 95-97 % Si produced from a mixture of quartz and charcoal. I have shown by several experiments that it is possible to refine commercial 90 % Fe-Si 13 144 146 147 148 149 151 152 14 153 154 156 157 158 98.1 97.8 98.4 98.6 97.4 98.3 98.2 97.6 97.8 97.3 97.6 97.0 97.9 97.5 97.3 with the relatively cheap hydrochloric acid to 95-97 % Si, as shown by Table 7, this quality of silicon, however, as mentioned above is of minor commercial importance. In this Table 7 and also in the following Tables 8-12, the percentage amounts of Fe, Al and Si O 2 shown in columns under the heading "Silicon Product" are based on the silicon product itself yielded as an insoluble product by the acid treatment of the raw material. As a result of systematic investigations, I have worked out a method for the production of high grade silicon by acid leaching of commercial 75-97 % ferrosilicon According to my process, 75-97 ' ferrosilicon, containing elementary iron and aluminium in a ratio Fe:Al by weight from 0 125:1 to 2 5:1 is subjected to the solvent action of aqueous hydrochloric acid, sulphuric acid or nitric acid, or mixtures of hydrochloric acid and sulphuric acid or nitric acid. My basic idea was to determine the relation between the relative amounts of the impurities in commercial 75-97 % Fe-Si, and the leaching effect of the relatively cheap and easily handled hydrochloric acid This problem was first studied in a pure theoretical manner; and the results thus obtained were verified by numerous experiments. 75-97 % Fe-Si may be considered approximately as a Fe-Si-system containing the compound Fe Si 2 and the element Si It is a well known fact that these solid phases are insoluble in hydrochloric acid 75-97 % Fe-Si may also, to a certain degree of approximation, be considered as an Al-Fe-Si system, and according to the phase rule, the ternary system 785,609 785,609 contains a maximum of 3 solid phases in equilibrium with a liquid phase It may be supposed that two of these three solid phases are Si and Fe Si 2, the third solid phase, according to the results listed in Table 7, probably being a ternary,

hydrochloric acid soluble " AFe-Si-phase," as shown by the fact that elementary Al, Fe and Si are dissolved by hydrochloric acid If the modifying effect of impurities other than Fe and Al, is disregarded, 10 the results listed in Table 7 indicate that the hydrochloric acid soluble solid "phase" is a solid solution, or a mixture of hydrochloric acid soluble phases, the rapid cooling during the Fe-Si solidification process being respon 15 sible for the apparent deviation from the phase rule. TABLE 7 (%age by weight) Raw Material " 83 97 %" ferrosilicon Silicon Product Mother Total Total Total (Total): (Total)% (elem)Fe: % Grain Total Total % Grain Fe ++ Ref % Si %Fe % Al Fe: AI A 1,03 (elem)A 1 Sic 2 Size Notes % Fe % Al Si O)2 Size AI+++ Notes 6 ( 05) 90 0 6 64 1 76 3 77 0 4 4 25 10-30 mm 4 11 0 43 1 79 4 94 5 3 37 1 02 3 30 0 4 4 20 2 45 0 40 1 22 1 g 7 ( 16) 95 5 2 77 0 95 2 92 0 5 4 00 max 8 mm 2 04 0 55 1 84 S 6 ( 03) 89 0 7 11 1 96 3 63 0,3 3 95 10-30 mm 4 50 0 33 1 72 o, 001 C> 000 300 L 82 2 12 05 3 49 3 44 0 4 3 45 max 1 mm v 8 35 0 60 1 27 O o 7 ( 8) 94 2 3 66 1 48 2 47 0 5 3 00 max 8 mm 2 25 0 54 1 48 b H 2 ( 3) 96 8 2 09 0 83 2 52 0 3 3 00 10-30 mm 1 40 0 42 1 74 7 ( 10) 94 9 2 91 1 22 2 39 0 5 2 95 max 8 mm 2 04 0 55 1 36 o 7 ( 14)95 3 2 88 1 21 2 38 0 4 2 85, 1 60 0 43 - 1 60 2 ( 1) 96 7 2 05 0 93 2 20 0 3 2 75 o 10-30 mm S; 1 34 0 33 1 23 2 ( 2) 96 5 2 18 0 97 2 25 0 3 2 75 g 10-30 mm 1 40 0 38 1 36 7 ( 16) 94 6 3 23 1 38 2 34 0 4 2 70 max 8 mm | | 1 90 0 44 1 84 7 ( 1) 95 9 2 65 1 15 2 30 0 3 2 65 1 52 0 28 1 32 7 ( 3) 95 9 2 65 1 17 2 26 0 3 2 65 1 34 0 32 1 55 -. 6 (C 60) 91 0 5 19 2 19 2 35 0 2 2 50 10-30 mm c 1 20 0 21 1 99 3 e ( 12) 93 53 52 1 51 2 33 0 2 2 50 1 06 O 19 1 48 303 L 83 1 10 88 4 41 2 46 0 4 2 50 max l mm 6 28 0 45 1 17 o e 7 ( 14) 95 8 2 44 1 15 2 10 0 3 2 40 max 8 mm 1 51 0 32 1 60 7 ( 12) 96 0 2 45 1 24 1 98 0 3 2 25 1 19 0 30 1 35 3 g ( 16) 93 04 43 2 35 1 90 0 15 1 95 10-30 mm 1 58 0 16 1 30 c\ 00 154 C 0 \ O corresponds to the reversible transition process: Fe Si 2 + liquid ' z-y-phase. The liquid area (A + B) in the Figure of the accompanying drawing may be sub-divided 70 into two areas, A and B by a straight line from the Si-vertex to an arbitrary point r between o and b on the line b r o a d g Starting with a liquid alloy belonging to the area A, Si crystallizes primarily Si + Fe Si 2 secondarily 75 along the line ba, and at the peritectic point o some of the solid Fe Si 2 reacts with the liquid, forming the y-phase If the crystallization process proceeds very slowly, the system is kept in a quasistatic, thermodynamic equilibrium 80 condition, i e the system is at all times infinitesimally near a state of thermodynamic equilibrium, and the liquid solidifies at the point o at a constant temperature of about 8700 C On the other hand, starting with a 85 liquid alloy belonging to

the area B, all of the Fe Si 2 phase reacts with the liquid if the temperature is kept constant at 8700 C Thus the system gains one degree of freedom, and the crystallization process may proceed along 90 the line oa in a quasistatic thermodynamic equilibrium condition At the peritectic point a the y-phase reacts with the liquid, forming the $-compound,-A 145 i 2 Fe. The peritectic transition processes commonly 95 never proceed to completion At the point o, the surface of the Fe Si 2 crystals probably are covered by the 7-phase in the same manner as the surface of the Fe Al, compound is covered with the DR-phase along the line gd as shown 100 by Urazolf and Sjasjin The Fd Si 2-compound thus disappears from the equilibrium system and the crystallization process may proceed along the line oa, the Fe Si 2 phase being coated by the y-phase Hence, it may be expected 105 that a liquid alloy belonging to the area A commonly crystallizes along the line b r o a d, and solidifies finally at the invariant point d as a ternary eutectic comprising Si + Al + Al 4 Fe 2 Si, the 7-phase compound having reacted 110 with the Fe Si 2 compound. The y-phase crystallizing at the invariant point o must, of course, have a definite cornpositiont, but it is not yet known if the 7phase crystallizing along the line oa has a 115 definite composition or a continuously changing one, corresponding to a solid solution of Al, Fe, and Si. The experiments listed in Table 8 were carried out with Al-Fe-Si-alloys belonging to 120 the areas A and B in the Figure, prepared by mixing liquid 751 % ferrosilicon with solid aluminium The alloys were quenched in water. It may thus be expected that the Fe Si 2 crystals grew relatively small, and that the 125 peritectic transition process, corresponding to the point o, only penetrated a very thin surface layer of the Fe Si, crystals Table 8 shows that the relation Fe: Al by weight of solid phases (y, 13, Al) leached out by hydrochloric acid is 130 The maximum number of solid phases in commercial 90 % Fe-Si is approximately controlled by the phase rule, at a constant pressure, by the relation: Maximum number of solid phases=Number of components (Si, Fe, Al, etc). Some of these solid phases are insoluble only in hydrochloric acid, as for example Fe Si 2. Some solid phases, as for example the "AlFe-Si-phase," are soluble in hydrofluoric acid, hydrochloric acid or other strong acids A great number of solid phases decompose in water, as for example Ca Si,, Mg 2 Si, Al 4 C,. According to the principle of le Chatelier an increase of one component, as for example Al, which together with iron forms a hydrochloric acid soluble phase, results in an increase in the

relative amount of the hydrochloric acid soluble phase, containing iron, at the cost of other solid phases, containing iron, i e at the cost of the phase Fe Si 2, which is insoluble in hydrochloric acid. With reference to the accompanying drawing and to Table 1, as mentioned above, com2 mercial 90 % Fe-Si may be treated as an AlFe-Si-system, and the more general theoretical considerations correlated with the liquid area of the Al-Fe-Si-system worked out by Urazoff and Sjasjin (Metallurgist Moskva No 4 ( 88), 1937) According to these authors, the liqui 4 area in the Si vertex may be divided into two areas (A+B) and C In a liquid alloy belonging to the area (A + B) Si crystallizes primarily along a straight line through the point representing the composition of the initial liquid alloy and the Si vertex; Si+Fe Si 2 crystallises secondarily along the line bo; and Si Fe Si, + y-phase at the invariant point o at a temperature of approx 870 C They condude that the y-phase is a solid solution. A liquid alloy belonging to the area C crystallizes primarily as Si, secondarily as Si+y-phase along the line oa, and thirdly as Si + P-phase + Al at the invariant point d The v-phase reacts peritectically with the liquid at the point a, forming the 13-phase According to Jiniche and Hanemann (Aluminium-Archiv 1936 ( 5)), the 13-phase is a ternary comnpound with the composition Al 45 i Fe. The relation Fe: Al by weight for a liquid corresponding to the point o in the Figure is approximately 0 9: 1, but the experiments listed in Table 7 indicate the existence of one or more ternary compounds or solid solutions with a relation Fe: Al by weight being greater than 0 9: 1 It seems very improbable that o is a simple ternary eutectic point If it were so, the relation Fe:M Al for the y-phase would have to be less than 09:1, and the results listed in Table 7 would have to be explained by a relatively rapid transition process in the solid state between the V-phase and the Fe Si 2compound Transition processes, however, proceed commonly very slowly in the solid state, and thus it may be assumed that the point o 785,609 approximatively 1: 1 This result indicates that, in spite of the rapid cooling, some of the Fe Si 2compound did really react with the liquid, forming the y-phase, probably owing to the relatively large surface area of the Fe Si 2-phase. On the other hand, by annealing at 850 8600 C it may be expected that the large surface area of the Fe Si 2-phase favors the transition process: Fe Si 2 + liquid y-phase. The composition of the liquid in this equation does not, of course, correspond to the point o in the Figure. The Tables 9, 10 and 11 show the result of hydrochloric acid leaching of annealed AlFe-Si-alloys, If we assume that the transition process

proceeds to completion by annealing at 850-860 C over a period of 20 hours, experiment II in Table 10 indicates that the relation Fe: Al by weight of the y-phase, crystallizing at the point o, is approximatively equal to 2 15: 1. TABLE 8 (%age by weight) Raw Material Silicon Product Mother Liquor Ref Total Total Total (Total):(Total) % (elem) Fe: % Grain Total Total % Grain Fe +:AI+ + + % Si % Fe % Al Fe: Al Al O 03 (elem) Al Si Os Size % Fe % Al i O 2 Size ca. I 730 15 10 25 1,5:1 0 4 3:2 O h 5 2 0 77 14 1 08:1 II 68 3 25 4 10 2 2 5:1 2 5:1 17 56 1 81 16 1 10:1 III 66 2 18 71 14 52 1 3:1 1 L 3:1 R 5 44 0 87 15 1 01:1 The liquid alloy was quenched in water. TABLE 9 (%age by weight) ca. I ( 2) 73 0 15 3 10 2 1 5:1 04 1 5:1 p l 3 36 0 60 11 1 29:1 II ( 2) 74 0 17 7 6 8 2 6:1 2 6:1 10 75 1 20 14 1 35:1 III ( 2) 69 0 17 1 12 0 1 45:1 1 45:1 3 16 0 67 18 1 26:1 The quenched alloy was heated to 900 C and cooled down to 6000 C in 3 hours. 00 t A,. 501 TABLE 10 (%age by weight) The quenched alloy was annealed at 8000 C for 200 hours. TABLE 11 (%age by weight) I ( 4) 75 13 4 8 7 II ( 4) 68 5 20 5 9 5 Ill ( 4) 63 0 21 4 14 2 1.51 2.2:1 1.5:1 ca 0.4 1.5:1 2.2:1 1.5:1 o N 0 41 0 24 0 O 1 62 0 76 0.01 m 4 95 1 09 The quenched alloy was annealed at 8600 C for 20 hours. The fact that a relatively great amount of the Al remains in the residue from some of these experiments with Al-Fe-Si-alloys, may easily be explained by occlusion phenomena, owing to the rapid cooling of the liquid alloy. Table 12 shows the results of hydrochloric acid leaching of a great number of silicon-rich Al-Fe-J Si-alloys, the ratio Fe: Al by weight in the mother liquor ranging between 1: 1 and 2: 1, depending on the speed of crystallization of the liquid alloy These experiments prove that hydrochloric acid leaching of commercial 75-97 % Fe-Si with a Fe: Al ratio by weight less than 1 5: 1, results in a sufficient degree of refining If the raw material for hydrochloric acid leaching is prepared by slow cooling or annealing below 8700 to complete the transition process: Fe Si 2 + liquid-y-phase, a Fe: Al ratio by weight between 1 5:1 and 2:'1 also results in a sufficient degree of refining. Go 0 \ 17 1 1.53:1 2.15:1 1.20:1 \ O Representative examples based on numerous acid leaching experiments. TABLE 12 (%age by weight) Mother Raw Material Silicon Product Liquor Consumption %Ca O of 33 % H Cl Ref Total Total Total A 1203 + (elem) Fe: Grain Total Total Si O O Grain Fe+ +: per 1000 kg % Si % Fe % Al % Si O 2 (elem) Al Size % Fe % Al % Size Al+++ Notes raw mat.

17 4 6 0 0 4 0 4 3:1 Max 9 0 0 4 12 Max 1 5:1 1350 kg. 9 8 3 5,,,, 30 5 3,, 7 1,, 750,, 92 5 1 1 9,,,,,, mm 2 8,, 3 5 mm,, 00 'H 360,, 3 0 1 2,,,,, 1 8,, 2 5,,,, 200 97 1 5 0 7,,,,,,,, 1 1,, 1 5,,,, 70,, 16 5 6 8,,,, 2 5:1,, 7 0 0 5 13,, ,, E 1530 kg. 9 5 4 O,,,,,,,, 4 2 7,, ,, o 00,, 2 92 5 O 2 2,,,, 2:,,2 3 O 4,, ,, 430,g 2 8 1 3,,,,,,,, 14,, 3,, ,, 220,, 2 6 1 5,,,,,,,, 10,, 30,,,, B q's) 26 10,, 97 1 4 0 8,,,,,,,, O 8 0 4 1 5,,,,10 0 15 4 7 9,,,, 2:1,, 4 4 O 6 14,, ,, 1800 kg. 8 8 4 6,,,,,,,, 2 8 O 9,, 1 1 1150,, 3 92 4 6 2 5,,,,,, 1 6 O 4 O p,, 500,, 2 6 1 5,,,,,,,, O O 3 O,,,, 260,, 13 8 9 4 1 5:1,, 2 9 O 7 16,, approx, 2000 kg. 7 8 5 4,,),,3,,) 1 8 0 6 8,, 1 25:1 () 1100, 4 92 4 1 2 9,,,,, 1 1 0 5 4 5 O,,550, 2 4 1 8,,,,,, 0 7 0 4 3 5,,330 , 97 1 2 1 0,,,,, 0 3 0 3 2 5,, 120, The "speed of cooling" of the crystallization of the raw material corresponds to approx 100 WC/hour below 8700 C, and to approx 200 'C per hour above 870 'C. \ O Representative examples based on numerous acid leaching experiments. TABLE 12-continued (%age by weight) Mother Raw Material Silicon Product Liquor Ca O Consumption %Ca O of 33 % H Cl Ref Total Total Total A 1203 + (elem) Fe: Grain Total Total Si O 2 Grain Fe++: per 1000 kg % Si % Fe % Al % Si O 2 (elem) Al Size % Fe % AI % Size AI+++ Notes raw mat. 11 6 11 8 0 4 0 4 1:1 Max 0 9 0 7 20 Max approx 2300 kg. 6 6 6 8,,,,,, 30 0 7 0 6 10 1 1:1 1300,, 92 3 4 3 6,,,,,, mm 0 5 0 4 5 5 mm,, 600,, 1 9 2 1,,,,,,,, 0 3 0 3 4,,,, 360,, 97 0 9 1 1,,,,,,,, 0 2 0 2 3,, ,, 165,, 7 7 15 7,,,, O 5:1,, 0 6 0 7 20,, approx & 2950 kg. 4 4 9 0,,,,,,,, 0 5 0 6 10,, 0 5:1 1550 6 92 2 3 4 8,,,,,,,, 0 4 0 4 5 5,, 75 1 3 2 8,,,,,,,, 0 3 0 3 4,, ,, Xq 450,, 97 0 6 1 4,,,,,,,, 0 2 0 2 3,, ,, 225,, 3 8 19 6,,,, O 2:1,, 0 5 0 7 20,, approx 3025 kg. 2 2 11 2,,,,,,,, 0 4 0 6 10,, 0 2:1 A O 1770,, 7 92 1 2 6 0,,,,,,,, 0 3 0 4 5 5,,,, 900,, 0 7 3 5,,,,,,,, 0 2 0 3 4,, ,, 500,, 97 0 3 1 8,,,,,,,, 0 1 0 2 3,, ,, 250,, 2 1 21 2,,,, O 1:1,, 0 5 0 7 20,, approx 3150 kg. 1 2 12 2,,,,,,,, 0 4 0 6 10,, 0 1:1 CA 2050,, 8 92 0 6 6 5,,,,,,,, 0 3 0 4 5 5,,,, 930,, 0 4 3 7,,,,,,,, O 2; 0 3 4,,,, 525,, 97 0 2 1 9,,,,,,,, 0 1 0 2 3,,,, 260,, The "speed of cooling" of the crystallization of the raw material corresponds to approx 100 C/hour below 870 C, and to approx 200 C above 870 C. -.0 Representative examples based on numerous acid leaching experiments. TABLE 12-continued (%age by weight) Mother Raw Material Silicon Product Liquor Consumption %Ca O of 33 % H Cl Ref Total Total Total A 1203 + (elem) Fe: Grain Total Total Si O 2 Grain Fe++: per 1000 kg %

Si % Fe % Al % Si O 2 (elem) Al Size % Fe % Al % Size AI+++ Notes raw mat, 17 4 6 0 0 4 0 4 3:1 Max 6 2 0 4 15 Max 2:1 1500 kg. 9 9 3 5,,,,,30 3 7,, 9 1,, 850,, 9 92 5 1 1 9,,,,, mm 2 1,, 5 mm C,, 400, 30 1 2,,,,,, mm 1 4 X 3 mm 210, 97 1 5 0 7,,,,,,,, O 9,, 2,,, 80,, 16 5 6 8,,,, 2 5:1,, 3 9 0 5 18,,,, W 1700 kg. 9 5 4 0,,,,,,,, 2 5,, 10,,,, 950,, 92 5 O 2 2,,,,,, 1 4,, 6,,, 5 460, 28 1 3 " " " " 1 O l 3 5 " '' 250,, 97 1 4 0 8,,,,,,,, 0 6 0 4 2 0,,,, 110,, 15 4 7 9,,,, 2:1,, 4 3 0 5 20,, approx 1800 kg. 8 8 4 6,,,,,,,, 2 6, 10,, 1 5:1 1150,, 11 92 4 6 2 5,,,, 1 4,, 7, 500, 2 6 1 5 " ", ' 1 O,, 4 5,,,, 260,, 97 1 2 0 8,,,,,,,, 0 6 0 4 2 5,,,, t 120,, 13 8 9 4,,,, 1 5:1,, 0 7 0 7 20,, approx 2100 kg. 7 8 5 4,,,,,, 0 6 0 6 10,, 1 5:1 C) 1150,, 12 92 4 1 2 9,,,,,,,, 0 5 0 5 7,,,, 600,, 2 4 1 8,,,,,, 0 4 0 3 4 5,, 330,, 97 1 2 1 0,,,,,,,, 0 3 03 2 5,,,, 160,, The "speed of cooling" of the crystallization of the raw material corresponds to approx 20 WC/hour below 870 'C, and to approx 200 WC/hour above 870 WC. N) Co 0 s 0 ^ Representative examples based on numerous acid leaching experiments. TABLE 12-continued (%age by weight) Mother | 1 Raw Material Silicon Product Liquor Consumption %Ca O of 33 % HC 1 Ref Total Total Total A 1203 + (elem) Fe: Grain Total Total Si O 2 Grain Fe++: per 1000 kg % Si % Fe % Al % Si O 2 (elem) Al Size % Fe % Al % Size Al+++ Notes raw mat. 11 6 11 8 0 4 0 4 1:1 Max 0 6 0 7 30 Max Approx 2300 Kg. 6 6 6 8,,,,,, 30 0 5 0 6 10 1 1:1 1300,, 13 92 3 4 3 6,,,,,, mm 0 4 0 4 7 mm,, OX H 600,, 1 9 2 1,,,,,,,, 0 3 0 3 4 5,,,, Of 360 97 0 9 1 1,,,,,,,, 0 2 0 2 2 5,,,, 165,, 7 7 15 7,,,, O 5:1,, 0 5 0 7 20,, Approx Hi g 2950 kg. 4 4 9 0,,,,,,,, 0 4 0 6 10,, 0 5:1 W 2 1550,, 14 92 2 3 4 8,,,,,,,, 0 3 0 4 7,,,, W 750 1 3 2 8,,,,,,,, 0 2 0 3 4 5,,,, 450,, 97 0 6 1 4,,,,,,,, 0 1 0 2 2 5,,,, 225 3 8 19 6,, , O 2:1,, 0 5 0 7 20,, Approx 3025 kg. 2 2 11 2,,,,,,, O 4 0 6 10,, 0 2:1 1770,, 92 1 2 6 0,,,,, I, 0 3 0 4 7,, ,, 900,, 07 35,,,,,,,, 0 2 0 3 4 5,, 500,, 97 0 3 1 8,,,,,,,, 0 1 0 2 2 5,,,, 250,, 2 1 21 2,,,, O 1:1,, 0 5 0 7 20,, Approx O 3150 kg. 1 2 12 2,,,,,,,, 0 4 0 6 10,, 0 1:1 2050,, 16 92 0 6 65,,,,,,,, 0 3 0 4 7,,,, 930,, 0 4 3 7,,,,,,,, 0 2 0 3 4 5,,,, 525,, 97 0 2 1 9,,,,,,,, 0 1 0 2 2 5,,,, 260,, The "speed of cooling" of the crystallization hour above 870 C. of the raw material corresponds to approx 20 per hour below 8700 C, and to approx 2000 C per 00 0. \ 0, It is, of course, very advantageous to cool the raw material for hydrochloric acid leaching very slowly in the temperature range corresponding to the primary crystallization of Si, to obtain a coarse

structure, thus reducing the occlusion phenomena to a minimum On the other hand, in the temperature range corresponding to the secondary crystallization of Si + Fe Si 2, rapid cooling is very advantageous by producing small Fe Si 2 crystals, favoring the transition process mentioned above. The silicon content of the raw material for hydrochloric acid leaching is of minor importance from a technical point of view. Calculations show, however, that 75 % Si is the lower Si-limit for the hydrochloric acid leaching to be profitable compared with the quartz charcoal process The upper limit for my process is chosen as 97 % Si, due to the fact that this quality of silicon may be produced from a mixture of coke and charcoal. Experiments carried out by me show that a desired ratio Fe: Al by weight in the ferrosilicon used may be produced as follows: 1) The ferrosilicon furnace is discharged by penetrating the furnace mantle with graphite rods in lieu of the common iron rods. 2) The quartz and coke may contain A 120, as an impurity. 3) The iron mantle of the Soderberg electrode may be replaced by an aluminium mantle. 4) A 120 in some form, or elementary Al, may be added to the mixture of quartz and coke. 5) Elementary Al may be added to the liquid ferrosilicon during the discharge of the furnace, preferably as small lumps of 50-200 g. The most important condition is to keep the composition of the raw material under control, and any man, skilled in electric furnace handling, will easily obtain a desired Fe: Al ratio by weight by one or more of these methods My process may also be carried out with a raw material selected from commercial ferrosilicon having the desired Fe: Al ratio by weight. Elementary Al consumes 3 times as much hydrochloric acid as the same quantity of iron by weight, giving H (Al CI 4) and H (Fe Cl,), respectively Thus it is obvious that it is an unnecessary waste of hydrochloric acid to leach a raw material containing Fe: Al by weight in a ratio less than 1:1 The least possible con sumption of acid is, of course, achieved with a raw material produced by very slow cooling or annealing below 870 C, having a Fe:Al ratio by weight in the range 15:1 -to 2 5:1. If the liquid ferrosilicon is poured into well insulated crucibles having a high volume to surface ratio in_ quantities between 500 and 1000 kg, the temperature commonly drops with a speed approximately equal to 1000 C. hour-1 below 8700 C The experiments listed in Table 12 show that a ferrosilicon produced in that way contains hydrochloric acid soluble iron and aluminium in a ratio by weight of approximately 15: 1 This

ratio appears to be 70 the most economical for my process, due to the fact that a raising of the ratio from 1 5: 1 to 2: 1 by an extremely slow cooling during the crystallization process of the raw material below 8700 C is a rather costly procedure 75 Table 12 shows, however, that a raw material containing 92-97 % Si with a Fe: Al ratio by weight in the range 15: 1 to 2: 1 also gives a sufficient degree of refining, in spite of the fact that the Fe: Al ratio by weight in the 80 mother liquor is equal to approximately 15: 1. The upper limit of the Fe: Al ratio by weight for my process thus may be chosen as 2: 1 in the range 92-97 % Si, and as 1 5:1 in the range 75-92 % Si, the Fe: Al ratio by weight 85 in the motor liquor being less than or equal to 1 5: 1 If the ferrosilicon is produced by an extremely slow cooling (less than 200 C. hour-1) or annealing below 8700 C, the upper limit of the Fe: Al ratio by weight for 90 my process may be chosen as 2 5:1 in the range 92-97 % Si, and to 2:1 in the range 75-92 % Si, the Fe: Al ratio by weight in the mother liquor being equal to approximately 2: 1 95 The amounts of acid necessary for the refining of representative silicon alloys according to my process are listed in Table 12. Commercial 90 % Fe-Si commonly contains 0.2-0 6 % A 1,02 The Fe: Al ratio for my 100 process always refers to elementary iron and aluminium The ratio (total) Fe: (total Al by weight from the ordinary analysis of commercial 90 % Fe-Si thus has to be corrected to a slight degree If necessary the amount of 105 A 120, may be determined by chlorination at6000 C, removing Si, Fe and Al as chlorides (gas) A 120,, Sio 2, Ca O, Ca CI 2, Mg C 12 and small amounts of other impurities remain The total amount of A 120 o is easily found in the 110 residue from the chlorination process by common methods. Lower Fe: Al ratios by weight than 1: 8 give excellent technical results, but from an economical point of view the lower limit of 115 the ratio Fe Al by weight for my process is chosen as 1: 8. I have found that it may also be profitable to leach 75-97 % Si according to my process with sulfuric acid, nitric acid, or mixtures 120 of these acids with hydrochloric acid, hydrochloric acid, however, giving the best result both technically and economically. The residue from the hydrochloric acid leaching may, of course, be given a hydro 125 fluoric acid treatment to obtain a purer silicon. A great number of experiments show that the speed of leaching with hydrochloric acid is approximately proportional to the acid concentration 130 785,609 subjecting a ferrosilicon containing from 75 to 97 % silicon by weight and elementary iron and aluminium in the ratio Fe: Al from 0 125: 1 to 1 5: 1 by weight to the said solvent action. 3 Process according to claim 1 comprising, subjecting a ferrosilicon

containing from 92 to 97 % silicon by weight and elementary iron and aluminium in the ratio Fe: Al from 1 5: 1 to 2: 1 by weight to the said solvent action. 4 Process according to claim 1 comprising, subjecting a ferrosilicon containing 75 to 97 % silicon by weight and elementary iron and aluminium in the ratio Fe: Al from 1 5: 1 to 2:1 by weight to the said solvent action. Process according to claim 1 comprising, subjecting a ferrosilicon containing from 92 to 97 % silicon by weight and elementary iron and aluminium in the ratio Fe: Al from 2: 1 to 2 5: 1 by weight to the said solvent action. 6 Process according to any one of the preceding claims wherein the solvent action is effected at an elevated temperature. 7 Process according to any one of the preceding claims wherein the residue from the hydrochloric acid solvent action is treated further with hydrofluoric acid. 8 Process for the production of high grade silicon according to claim 1 substantially as herein described. 9 High grade silicon which has been produced by a process according to any one of the preceding claims. MIEWBURN, ELLIS & CO, 70/72, Chancery Lane, London, W C 2, Chartered Patents Agents. Below 400 C the reaction proceeds very slowly, but on raising the temperature from to 500 C, the speed of leaching is approximately doubled Thus at 80 C the speed of leaching is 8-16 times as great as at 40 C. The speed of leaching at the beginning of the procedure is always relatively fast, but it slows gradually down in a couple of hours. Hence it is very convenient to start at 200 C. with commercial 30-3 '51 % hydrochloric acid, and raise the temperature slowly to keep the speed of leaching at a constant rate. Sulfuric acid (or nitric acid) mixed with some chloride, such as Na CI or Ca C 12 gives hydrochloric acid, suitable for leaching according to my process. The experiments listed in Table 12 indicate that most of the aluminium is leached out by hydrochloric acid over a period of 7-14 days. The remaining aluminium consists of A 12 O and occluded " elementary " aluminium as Al, Al 4 Si 2 Fe and y-phase By prolonged hydrochloric acid leaching over a period of 1 month 0.2-0 3 % Al commonly still remains in the residue.

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* GB785610 (A)

Description: GB785610 (A) ? 1957-10-30

Improvements relating to fireproofing of textile materials

Description of GB785610 (A)

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PATENT SPECIFICATION Inventor: JOHN DONALD BROATCH Date of filing Complete Specification: June 8, 1955. Application Date: July 1, 1954 7855610 No 19292/54. Complete Specification Published: Oct 30, 1957. Index at acceptance:-Class 140, P 3 (C: F 2: G 5). International Classification:-DO 6 m. COMPLETE SPECIFICATION Improvements relating to Fireproofing of Textile Materials We, THE BRITISH JUTE TRADE RESEARCH Assoc IAT Io N, a British Company limited by guarantee, of Kinnoull Road, Kingsway West, Dundee, Angus, do hereby declare the invention, for which we pray that a patent may be

granted to us, and' the method by which it is to be performed, to be particularly described in and by the following statement: - This invention relates to the fireproofing of textile materials, in the form, for example, of fleeces, fabrics, yarns or fibres, in order to render them fireproof with a high degree of resistance to removal of fireproofing agent by leaching The invention is more especially concerned with textile materials made from or including a proportion of naturally occurring cellulosic fibres or regenerated fibres of cellulosic origin. The object of the invention is to provide an improved fireproofing treatment which is reasonably simply carried out, which will be lasting in its effects, and which will provide a material resistant to flaming and which will not smoulder. In accordance with the present invention we provide a process for fireproofing textile materials characterised by the step of treating the material with an aqueous dispersion containing ortho-antimony phosphate and a chlorine-containing vinyl thermoplastic resin, together with a suspending agent for maintaining the antimony ortho-phosphate on suspension. Preferably the resin is one which has been internally modified, for example, by copolymerisation in order to avoid the necessity for final high temperature treatment Alternatively a plasticiser may be added, for example, tricresyl phosphate, in which case a final high temperature curing at a temperature of 1500 C is necessary in order to fuse the plasticiser and the resin If desired, inert fillers such as china clay can also be included. The invention further comprises textile materials when fireproofed by the methods herein set forth. It has been found that this treatment provides a very high degree of fire resistance; the combination of chlorine and antimony inhibits flaming, and the phosphatic content inhibits glow or smouldering. Furthermore this resistance to flaming and smouldering is retained after outdoor weathering for periods in excess of three months or after immersion in sea water for at least one month. We have found it an advantage to use at least 50 % by weight of resin in the treatment, but the amount of antimony ortho-phosphate can be varied between 5 % and 18 % by weight according to the standard of performance required. Both leached and unleached samples give satisfactory performance when examined by any of the testing methods in current use. It is also possible by applying fairly simple mechanical processes to produce a wide range of finishes on a given type of cloth which vary continuously from a cloth with soft handle to stiff board-like material Calendering can also be carried out to give a range of

surface finishes The chemicals can be applied to the cloth by various means, for example, impregnation, padding, or by means of doctor blades. The following examples are now described. EXAMPLE I Woven jute fabric is padded through a bath consisting of: Internally modified chlorinecontaining vinyl resin aqueous dispersion ( 55 % solids) By weight 76 % Antimony ortho-phosphate (Sb PO 4) 12 % Suspending agent such as sodium carboxy methyl cellulose (medium viscosity) 2 % _aqueous solution 4 % Water 8 % followedl by pressing between rollers in order _ Joi to squeeze out excess liquor leaving 150 % increase in weight of the cloth in the wet state This treatment gives a very high degree of resistance to flaming and to smouldering. EXAMPLE II Where a lesser degree of protection is required, the cloth may be padded through the same mixture as described in Example I, but the increase in weight of the cloth in the wet state can be reduced below 150 % but to a figure not less than 130 %. EXAMPLE III Woven jute fabric is padded thre consisting of: Internally modified chlorine containing vinyl resin aqueou dispersion ( 55 % solids) Antimony ortho-phosphate (Sb PO Suspending agent such as sodiun carboxymethyl cellulose ( 2/, aqueous solution) followed by pressing between roller squeeze out excess liquor, the ma Z 5 being dried, preferably through a he It is not necessary to employ hig I tures and the performance of the even if dried at room temperatur factory. EXAMPLE IV A woven jute fabric is padded bath consisting of: Internally modified chlorine containing vinyl resin aqueou dispersion ( 55 % solids) Antimony ortho-phosphate (Sb PC Filler, e g china clay Suspending agent such as sodiun carboxy methyl cellulose (medium viscosity) 2 % aqueous solution Water This example has been form provide a less expensive mixture, filling power which can be used for fi the more openly woven fabrics ai same time reducing their permeabil this mixture a minimum of 150 % i weight of the cloth in the wet state is for imparting a high degree of flame and smoulder resistance to the clo EXAMPLE V A woven jute fabric is passed l bath consisting of: By weight Polyvinyl chloride aqueous dispersion ( 55 % solids) 66 % Tricresyl phosphate ( 65 % emulsion in water) 17 % 60 Antimony ortho-phosphate (Sb PO,) 10 % Dispersing agent such as sodium carboxymethyl cellulose ( 2 % aqueous solution) 7 % iugh a bath pressed between rollers so as to squeeze off 65 excess solution, and dried, preferably by By weight passage through a hot-air drier When

dry the material is given a further high temperaIs ture treatment in the range 130-150 'C for % a short period of time 70 An example of a suitable chlorine containJ) 12 % ing vinyl thermo-plastic resin as herein referred to is Geon (Registered Trade Mark) a 652 marketed by British Geon Ltd.

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* GB785611 (A)

Description: GB785611 (A) ? 1957-10-30

Improvements in or relating to chemical reactions

Description of GB785611 (A)

COMPLETE SPECIFICATION Improvements in or relating to Chemical Reactions 't'e, Esso RESEARCH AND ENGINEERING COMPNY, formerly known as Standard Oil Development Company, a corporation duly organised and existing under the laws of the State of Delaware, United States of America, having an office art Elizabeth, New Jersey, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly dcscribed in and by the following statemenu - The present invention is concerned with improvements in carrying out chemical reactions. More particularly, the invention is con.erncd with the activation or promotion of chemical reactions by nuclear radiation. In the operation of atomic pilcs large amounts of radioactive

by-products or waste materials are obtained. Apart from very minor quantities used in medical research and therapy and for various tracer techniques in ;industrial research and manufacturing processes, no large scale practical application has been found as yet for this quantity of radiation which is available at relatively high intensity levels. In addition, these highly radioactive waste materials cannot be readily discarded without danger to animal and vegetable life. Their steady accumulation presents a disposal problem. The present invention ready alleviates the difficulty of the problem and affords various additional advantages. In accordance with the present invention, thcre is provide d a process for carrying out n chemical reaction of the type in which the reaction is assisted by subjecting the reactant materials, before and/or during the reaction, to radiation emitted by radioactive material, which comprises maintaining the radioactive material in the lower portion of a ground excavation, maintaining in the excavation, above the radioactive material, a material shielding the atmosphere above the excava- tion from radiation emitted by the radioactive material, and introducing cr maintaininL the reactant materials in the lower part of the excavation sufficiently close to the radioactive material to allow radiation to reach the replants so introduced or maintained. In accordance with a preferred embodiment of the invention the reagents of such reactions are exposed to radiation emitted by the fission by-products of processes generating atomic power and,'or fissionable materials. These by-products include elements with atomic numbers ranging from 30 (zinc) to 63 (europium). The waste materials are formed in the course of converting uranium, thorium cr other fissionable material in an atomic reactor Other radioactive materials, such as naturally occurring radioactive materials, primary fis;ionable materials and various ma:erials made radioactive by exposure to ncutron radiation, such as radioactive cobalt (cho4'), europium 15', or europium 154, may also be used for the purposes of the invention. The use of high-energy ionizing radiation to activate chemical reactions is somewhat complicated by the fact that most of these reactions are between compounds containing only elements of low atomic number, i.e. atomic number 21 or lower, which do not effectively absorb energy from high energy radiation such as -6-rays. Such reaction mixtures may be sensitized so that a markedly greater amount of energy can be absorbed within the reacting mixture. This sensitization is effected in accordance with a preferred embodiment of the invention by

incorporating elements of high atomic number, i.e. atomic number 22 or greater, preferably 74 or greater, such as mercury within the reacting mixture in the form of a solution, suspension or emulsion. For reactions proceeding in the vapour phase, a vapour form of the elements may be used, e.g. mercury vapour in a hydrocarbon mixture. For preparing mixtures in the liquid phase it may be advantageous to employ ultrasonic vibration to obtain more uniform or more stable emulsions or suspensions of the sensitizing agent in the liquid. Instead of elements of high atomic number, their compounds, which are compatible with the reaction mixture, may be used for the same purposes. Examples of compounds which may be employed are metal salts of acidic materials such as inorganic acids, organic carboxylic acids, phenols and cresols, metal complexes such as the metal salts of the enol form of acetyl acetone and other chelate compounds, metal alkyls, and metallic carbonyls. Relatively small proportions of elements of high atomic number or their compounds are sufficient. Beneficial effects may be obtained by the addition of less than 1% by weight of these elements, based on reactants. Proportions of up to 5;6 by weight on the same basis are sufficient for most purposes. Another important embodiment of the invention resides in its application to chain reactions which involve the production of free radicals. This production of free radicals is activated by radioactive radiation in accordance with rhe invention. When such chain reactions are desired betwcen reactants which are not of the type which readily produce free radicals undcr the influence of ionizing radiation, the present invention provides for the incorporation into the reaction mixture of small amounts, for example, up to 10". by weight, preferably less than 5% by weight, of compounds which readily decompose to form free radicals. Examples of compounds of this typo are alcohols, aldehydes, metal alkyls, and organic acids. A highly desirable method of carrying out the invention which is particularly suitable for promoting the chemical reactions herein described simultancously affords a convenient mcans for storing large quantities of highly active radioactive elements in a condition in which they present no radiation hazard but can be readily utilized in irradiating reaction mixtures on an industrial scale. In accordance with this method and as shown in the accom- panying drawing, the radioactive materials are stored in the bottom of a concretelinod or metal-lined pit 1 which is filled with water to a level 3 sufficient to absorb the radiation being emitted. The radioactive materials 5 may be sealed in metal containers or under a thin layer of concrete 7 so that the water will be protected from contamination by direct contact with the radioactive materials.

For conducting continuous processes in the presence of nuclear radiation, pipes 9 may be lowered into the pit within effective reach of the radiation emitted by the radioactive materials and the reactants for the process may be passed through these pipes. For batch processes, containers 11 holding the reactants may be lowered into the pit in a position where they are exposed to the radiation. The manipulation of containers and other equipment within this pit may be observed with safety by personnel on the surface since the water acts as a shield for the nuclear radiation. Since carth is a more efficient shield than water, no radiation will pass through the ground around the pit. Since , J2 and v radiations do not produce secondary radioactivity, water of high transparcncy can be maintained in the pit by a slow circulation of fresh water supplied to the pit through pipe 13 and withdrawn through an overflow 15 into the sewer 17. A gentle agitation of the water, e.g., by a stirrer 19, so as to bring all of it occasionally into the zone of intense radiation prevents the pollution of the water by aquatic algae and bacteria. The shielding requirements for point sources of radioactivity are presented in the table below. For radioactivity which is not concentrated in a point source but is spread cut in a line or over an area, additional shielding is required. These calculations show, however, that 15-20 ft. of water provide adequate shielding for any quantity of radiation that might conceivably be required. SHIELDING THICKNESS FOR 1 MILLIROENTGEN AN HOUR AT 1 FOOT FROM SHIELD (1). Inches of Shield Required For Quantity of Radioactive Cobalt (Curies) Lead Iron Concrete Water 1 6.5 10.3 28.1 65 10 8.0 12.7 34.6 80 100 9.5 15.1 41.1 95 1,000 11.0 17.5 47.6 110 10,000 13.5 19.9 54.1 125 100,000 15.0 22.3 60.6 140 (1) Permissible exposure is 50 milliroentgens a day. The above table also shows that the water shield may be replaced by relatively thin lead, iron or concrete shields. Numerous chemical reactions and industrial processes involving such reactions may be carried out in equipment of the type illustrated in the drawing using radiation intensities within the broad scope of, say, about 10,000-20,000,000 Roentgen/hr. and tadiation times of a few seconds to several hours, usually about 0.5-24 hrs. Scveral examples of such reactions are given below. However, the application of this

invention to these reactions is not limited to the use of a system of the type illustrated in the drawing. Other suitable means for carrying out chemical rcactions underground by exposing the react- ants to radiation of radioactive materials withcut presenting problems of disposal and danger to operating personnel may appear to those skilled in the art. Hydrocarbons or hydrocarbon mixtures, such as various petroleum fractions, may be subjected to various reactions for inter-mole- cular changes by exposure to radiation emitted from radioactive materials. Such reactions are, for example, cracking, reforming, hydrogenating, polmerizing and alkvlating. For crackitte to products of lower molecular weight, conditions of temperature, pressure and resistance timcs are preferably so choscn that the cracking products of the process are volatized and continuously removed from the further effects of radiation. Gas oils, including cycle stocks from other cracking processes. tnermal or catalytic, and other highboilin petroleum fractions, such as residual stocky and asphalts may thus be cracked to produce valuable lower-boiling hydrocarbons, uch as distillatcsF naphthas, motor fucls, and unsaturated hydrocarbons. Coke formation in this process is substantially less than in rliermal cracking prce sses. Conditions suitable for this purpose include temperatures of 100.-800 F. radiation intensities of 50,000 to 5.C00,000 Roentgen/br., and pressures of 5-250 lbs./sq. in. abs. Similar advantages are obtained in the hydrogenation of unsaturated hydrocarbons to produce less unsaturated hydrocarbons. The process may be carried out in accordance with the invention bv subjecting mixtures of unsaturated hydrocarbons. of a wide range ot molecular weight, and hydrogen to the influence of nuclear radiation emitted by fission products or other radioactive materials of suitable radiation intensity. Catalysts are not usually needed in this process, although they may be used, and temperatures and pressures substantially lower than those required in catalytic hydrogenation may be used. Temperatures of about - 50' to 500' F. and pressures of about 1-50 atm. are generally adequate at radiation intensities of 50,000 5:000,000 Roentgen/hr. Particular advantages are afforded in conncction with such reactions which normally require extreme conditions of temperature and Fressure as well as the use of catalysts. An outstanding example of such reactions is the fixation of nitrogen. When mixtures of N2 and H2 are irradiated using a large quantity of fission by-products, ammonia is produced at 0'-300' F. and without the use of catalysts. Polymers ranging in molecular weight from materials which are liquid at atmospheric temperatures to materials which are hard resins may be

produced from steam-cracked, catalytically cracked, or thermally cracked unsaturated hydrocarbons by exposing them to radiation from a strongly radioactive source, such as fission by-products. at temperatures of about - 40' F. to 350' F., residence times of about A to 24 hours and radiation intensitics of about 0,000 to 5,000,000 Roentgen/hr. In other polymerization reactions, hydrocarbon mixtures or pure hydrocarbons are exposed in the vapor state to radiation from radioactive elements at from - 100' to 400 F. This exposure may be carried out in a vessel in which the hydrocarbons of higher molecular weight formed by the reaction are condensed or adsorbed in a zone in which they are rcmoved from the effects of further radioactive bombardment. This may be accomplished by placing the condensing or adsorbing zone below the reacting zone, so that the relatively heavy reaction products drop out from the vapors into a position in which they are shielded from the radiation and from which they can be removed continuously by any suitable means, as will be obvious to those skilled in the art. Similarly. paraffins and isoparaffins are polymerized, with concurrent dehydrogenation, to useful products by irradiating with radioactive materials, e.g. <img class="EMIRef" id="026598857-00030001" /> irradiation CH,--CH, - HC-CH, --CHH-CCH-CH, I H2 CH, CH3 CH, CH, irradiation CH,CH - HC(CH1)3 ,--C,HH-C(CH,), ( H2 CH, CHi These reactions proceed at temperatures up to 300 F. or higher. When paraffin wax is irradiated by radioactive materials at about 70J400' F. and 50,Oo(50.O00,O00 Roentgens/hour, paraffin polymers useful as pour depressants and wax modifiers are obtained. Valuable polymerization products of the motor-fuel range are obtained when olcfins of low molecular weight, particularly isobutylene are polymerized by irradiating with radio active waste materials or radioactive cobalt at from -100' to +400' F. and 5x10L to S x 10* Roenrgens/hour. All the radioactivated polymerization processes have the advantage over previous processcs that the product is r.ot contaminated by polymerization catalyst and does not require catalyst removal. Alkylation reactions represent a further highly important field of application for the present invention. For example, aromatic compounds such as benzene, naphthalene, anthracene, phenols, anilinc, and chloro-, alkyl- and nit.o-aromatics may be alkylated by contacting

with alcohols, olefins, and alkyl chlorides while irradiating with radioactive materials at about 70'-350' F., high octane motor-fuels being thus produced. The activating energy of radioactive radiation may also be employed in accordance with the invention in a special application of cracking and polymerization reactions to facilitate and improve the recovery of crude oil and the utilization of natural gas. For the former purpose, high concentrations of radioactive fission products are pumped into an oil field through injection wells. This operation is similar to and may be run concurrently with '4ater flooding opcrations. Underground, the radiation from the injected fission products cracks those remaining portions of crude ptroleum which were not recovered in primary production from the oil field. The cracked products are more fluid than the original indigenous hydrocarbons and are, therefore, more easily flushed from the formation by water flooding or gas pressuring. The cit recovery is, therefore, larger than that resulting from simple water flooding or similar techniques. Although the fission products are byproduct materials from atomic energy plants and are not expensive, their recovery in part is desirable. This is possible by pumping them out from production wells after the recovery operation is completed. These recovered materials may be pumped back into rho ficld at positions closer to the front of the flood. If left in the formation, they assist in solving part of the disposal problem which is confronting atomic power plants with respect to their radioactive waste products. In accordance with the second of the two purposes mentioned above, radioactive fission products are pumped into subterranean strata or geological formations which are being used for the underground storage of natural gas or in which there are naturally occurring gas deposits. Over a suitably long period of time the radiation from the radioactive materials converts the hydrccarbon gas by consecutive or concurrent cracking and polymerization into a mixture of liquefiable or liquid petroleum products of higher molecular weight. The liquid petroleum products may be recovered as crude oil or as naphtha or gasotine, after separation from any hydrogen formed during the reaction underground. The hydrogen can be recovered separately and used as fuel or for conversion to other useful products, e.g. ammonia. The invention is also applicable to reactions of hydrocarbons or of other organic compounds with reagents, such as chlorine, bromine, fluorine, hydrogen, nitrogen, oxygen, sulphur or phosphorus or with reagents containing one or more of the foregoing, c.g. sulphur chloridcs and phosphorus sulphides. The invention is well adapted for halogenation, such as chlorination, of various hydrocarbons either as pure compounds or as complex

mixtures. The chlorination is effected by exposing a mixture of chlorine and a pure hydrocarbon or a hydrocarbon mixture to the radiation from a large quantity, corresponding to, say, about 50,5,000 Curics, of radioac:ive material at about 0 -300' F. The chlorinated product may be condensed continuously from the reaction mixture if a vapor phase reaction is employed as it may be removed by distillation if a liquid phase operation is carried out. Fission products formed as the by-product of atomic piles or artificial radioisotopes such as cobalt"' are the preferred source of inexpensive radioactive material for this process. The chlorinated hydrocarbons which can be produced include all molecular weight ranges from methyl chloride to chlorinated wax. Di- or polychlorinated hydrocarbons may be produced by a proper choir of the proportions of reacting, chlorine. Also, fluorination reactions may be carried out in a generally analogous manner. Thus, acids, amines or paraffins are fluorinated by mixing with HF and irradiating with radioactive materials at about - 40'- 300' F.. as illustrated by the equation <img class="EMIRef" id="026598857-00040001" /> radioactive CH,--COOH + 3 HF CF,COOH + 3 H radiation When mixtures of N and O., or of a halogen and 0,, together with hydrocarbons are irradiated by the by-products of fission, valuablc compounds of the hydrocarbons are obtained. Examples of such compounds are nitro yes and chiorohydrins. Nlixtures of CO, Cl, and unsaturated hydrocarbons may be irradiated to produce acid chlorides. Organic nitrogen compounds, such as nitro-methane, nitro-benzene, and tri-nitro-toluenc, may be obtained by irradiating mixtures of oxides of nitrogen and acyclic or cyclic hydrocarbons with radioactive materials. Thc invention is also applicabl to many oxidation reactions. Thus, hydrocarbons, such as methane, ethane, propane and isomers of butanc, pcntane, hexane, heptane, octane, nonage and decane, or mixtures thereof may be mixed with oxygen cr air 0.1-25', and passed through a reaction zone irradiated by radioactive materials, radioactive waste materials from atomic pilcs or radioactive metals from atomic piles, such as cobalt, until the desired degree of oxidation is obtained. The high energy content of radioactive radiation causes the oxygen to react with the hydrocarbon to form valuable alcohols, aldchydcs, kctones, acids or cpoxides. The mixture of oxygenated products arc particularly valuable: as motor-tuel blending agents or as a fuel alone. Combustion processes, when carried out underground, may also be aided by the process of the invention. More complete and more efficient

combustion of all types of fuels with greater heat output per unit volume and less smoke and stack solids is produced by conducting the combustion underground and in the presence of a high intensity of ionizing radiation, such as that obtainable from fission by-products from nuclear fission plants. Radiation intensities of about 1,000 to 100,0O0 Roentgen/hour are suitable for this purpose. Radioactive waste materials may also be used as a source of radiation to irradiate mincral-oil products in the presence of basic salts in a desulphurization process. A hydrocarbon to be desulphurized is passed through a reaction zone containing an alkaline material such as the hydroxide, oxide, or carbonate of an alkali metal or an alkalinc-carth metal while being irradiated from a radioactive source, such as radioactive waste material from atomic piles or radioactive metals, such as cobalt. Metals, such as zinc, mercury, tin and lead, may also be used to react with the sulphur from the hydrocarbon. The hydrocarbon portion of the sulphur compound is not lost in this process as the result of cracking by the atomic radiation. Conversely, in the absence of metals or bases cf the types mentioned above, radioactive waste materials from atomic piles or radioactive mctals such as cobalt may be used as a source of high intensity radiation to cause sulphur to combine chemically with a mineral oil, such as a cracked naphtha at ambient temperatures. Similarly, a dispersion of phosphorus sulphides, such as P2S3, P,SJ, and P S, in mineral oil may be irradiated at about 0 -300 F. to produce phosphosulphurized mineral oils useful as extreme pressure agents, detergents or similar addirives for lubricating oils. Radioactive radiation may likewise be used as the activation energy for the sulpha chlorination of hydrocarbons. The hydrocarbons which may range from C, to C,,, and which may include paraffins, isoparaffins, naphthenes, and alkyl aromatics are mixed with SO.. and Cl and the mixture is irradiated at about 0-3o0' F. to produce the desired sulphonyl chlorides. The resulting sulphonyl chlorides may be converted to the acid, ester, amid,,' or metal and amine salts. The acids of low molecular weight are useful as chemical reagents and the esters, armdes and salts of high molecular weight are useful as lubricating-oil additives, as will be understood by those skilled in the art. The invention may be advantageously applied to the improvement of high molecular weight hydrocarbon products, such as lubricalling oils, waxes and fuel oils. For example, it has been found that the predominant reaction of carboxylic acids when exposed to radioactive radiation at low temperatures is decarboxylation. Acids formed in lubricating oils by oxidation during use may, therefore, be destroyed by subjecting the oils to radiation from radicactive fission products

at temperatures below about ' F. In this manner, the carboxylic acids formed by oxidation are destroyed by decrirbexylation as they are formed. The same treament of lubricating oils may be used to improve their viscosity and pour-point characteristics which have been found to be beneficially affected by highintensity ionizing radiation of the type emitted by the by-products of atomic fission. It is known that combinations of molybdenum sulphide with mineral lubricating-oil are excellent lubricants and detergents. Highly efficient combinations of this type may be produced by exposing dispersions of small proportions, say about 0.1-2.0 wt. zinc of MoS2 in mineral lubricating oil to high intensity radiation, e.g. from fission waste materials at about 0 -300 F. Similarly, highly dcsirable combinations of heavy foe loils with lime may be produced. Heretofore, lime has been described above at about 0"--300" F. Another important example is the oxidation of SO to SO, and sulphuric acid. For this purpose, high intensity radiation from fission products is directed upon a mixture of SO and O at 0'--500" F. The SO3 formed may be absorbed in fuming sulphuric acid maintained in a portion of the reactor, which is shielded from the radiation. What we claim is: 1. A process for carrying out a chemical reaction of the type in which the reaction is assisted by subjecting the reactant materials, before and/or during the reaction, to radiation cmittcd by radioactive material, which comprises mainraining the radioactive material in the lower portion of a ground excatntion, maintaining in the escavation, above the radioactive material, a material shielding the atmosphere above the excavation from radiation cmitted by the radioactive material, and introducing or maintaining the reactant materials in the lower part of the excavation sufficiently close to the radioactive material to allow radiation to reach the reactants so introduced or mainrained. 2. A process according to claim 1, in which the radioactive material has been made radioactive by means of neutron irradiation. 3. A process according to claim l or 2, in which the radioactive material comprises fission was:e products. 4. A process according to any one of the preceding claims, in which the radioactive material comprises elements having atomic numbers from 30 to 63. 5. A process according to any one of the preceding claims in which the shielding material is water. 6. A proccss according to any one of the preceding claims, in which a stream of reactants is continuously passed through the lower portion

of the ground excavation. 7. A process according to any one of the precedintr claims in which the chemical reaction takes place between reactants consisting essentially of compounds containing elements having atomic numbers bclow 22. 8. A process according to claim 7, in which the chemical reaction takes place in the presense of a sensitizing element of atomic number 22 or more. 9. A process according to claim 8, in which the sensitizing element has an atomic number of 74 or more. 10. A process according to claim 8 or 9, in which the weight of the sensitizing element does not exceed 5 per cent of the weight of the reactants. 11. A process according to claim 10, in which the weight of the sensitizing element does not exceed 1 per cent of the weight of the reactants. 12. A process according to any one of claims 8-11, in which the sensitizing element is present in the form of a chemical compound. 13. A process according to any one of claims 8--1', in which the sensitizing element is mercury. 14. A process according to any one of claims 8-13 carried out in liquid phase subjeered to ultrasonic vibration to obtain a more uniform emulsion or suspension of the sensitizing agent in the liquid. 15. A process according to any one of claims 1-14 in which the chemical reaction involves the cracking of a high-boiling hydrocarbon to produce a more volatile hydrocarbon fraction. 16. A process according to claim 15 in which the cracking is carried out at tempera- tures of 100,500 F. and pressures of r 250 Ibs./sq. in. abs 17. A process according to any one of claims 1-14 in which the chemical reaction involves hydrogenating an unsaturated hydro carbon to produce a less unsaturated hydrocarbon. IS. A process according to claim 17 in which the hydrogenation is carried out at temperatures of about - 50 to 500 F. and pressures of about 1-50 atmospheres. 19. A process according to any one of claims 1-14, in which the chemical reaction involves the formation of ammonia from a mixture of nitrogen and hydrogen. 20. A process according to any one of claims 1-14, in which the chemical reaction involves polyrnerizing an unsaturated hydrocarbon to produce a liquid or resinous polymer. 21. A process according to claim 20, in which the polymerization is carricd out at temperatures of about - 100' F. to 400 F. and the residence time is from about i hour to 24 hours.

22. A process according to any one of claims 1-14, in which the chemical reaction involves polymerizing a paraffin or isoparaffin with concurrent dehydrogenation, to produce a hydrocarbon polymer. 23. A process according to claim 22, in which paraffin 'vax is irradiated by radioactive materials at about 70hay F. to give products useful as pour point depressants and wax modifiers. 24. A process according to any one of claims 1-I 4, in which the chemical reaction involves alkylating an aromatic compound with an alcohol, olefin or alkyl chloride to produce a high-octane motor fuel. 25. A process according to any one of claims 1-14, in which the chemical reaction involves oxidizing sulphur dioxide to sulphur trioxide. 26. A process according to any one of claims 1-14, in which the chemical reaction involves halogenating a hydrocarbon.

* GB785612 (A)

Description: GB785612 (A) ? 1957-10-30

Improvements in or relating to electrical integrating systems

Description of GB785612 (A)

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PATENT SPECIFICATION

785,612 Date of Application and filing Complete Specification July 9, 1954. No 20181 '54. Application made in France on July 10, 1953. Complete Specification Published Oct 30, 1957. Index at Acceptance:-Class 37, i G 2 (A 1: Bi: B 2: C 2), G 3 A 6. International Classification: -GO 6 g. COMPLETE SPECIFICATION Improvements in or relating to Electrical Integrating Systems We, SOCIETP, D'E LECTRO Xi I Qu J ST D'AUTOMATISMB, of 138, Boulevard de Verdun, Courbevoie, Seine, France, a Body Corporate organised under the laws of France, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - The present invention concerns electrical integrating systems of the kind including a servo-mechanism. An integrating servo-mechanism of the conventional kind includes a servo-motor which drives an output shaft and is so controlled from the output current of a high gain, D C transmitting, amplifier which receives an input signal of time varying amplitude, that the angular position of said shaft corresponds at any time to the time integrated value of said input signal Further to the mechanical output signal from this shaft, an electrical output signal may be obtained from the slider, actuated by this shaft, of a potentiometer which receives a reference D C. potential difference betwen its own terminals 'Of course, the range of operation of such an integrating arrangement is not restricted since the controlled shaft may freely be rotated as long as there is applied an input signal to be integrated thereby. In such an integrator, the control of the amplifier is ensured by providihg the combination with said input signal, and at the very input of the amplifier, of a further electrical signal, the amplitude variation of which simulates the differentiated value of the output signal of the device Said electrical voltage may be obtained either by connecting baclk the slider voltage of a potentiometer, controlled by the output shaft as hereinabove defined, through a differentiating capacitive coupling, to the input of the amnplifier, or by feeding said input with the lPrice 3 s 6 d l current issuing from a tachometer genera 50 tor driven by said output shaft. It is well-known that an integrating servo-mechanism of such a kind is only responsive to a narrow band of input frequencies, and also that it presents an 55 operative threshold whereby any small change in the input signal on either side of its zero poiut, lower than a certain

value of either polarity, remains without any action on the servo-mechanism and 60 consequently introduces an error in the value of the integration output signal. On the other part, a purely electronic integrator circuit is well-known, which includes a high gain D C transmitting 65 amplifier provided with a negative feedback path through a condenser from its output to its input, the input signal therefor being otherwise applied to said input through a series resistance Such an 70 integrator avoids the above-defined limitations or restrictions inherent to the servomechanism proper but its operative range is restricted in that there exists a maximum value, of either polarity, of the out 75 put signal beyond which the integration process cannot be carried on Since the maximum value may be reached during the period in which the input signal is applied, it is necessary to provide for a 80 resetting to zero of the integrator each time a predetermined value, lower than the integration maximum value, is reached by the output signal Such a reset may for instance be obtained by provid 85 ing a short-circuit of the Jaegative feedback condenser The actual value resulting from the integration however, can be known at any time by counting the humber of such resets during an operative 90 period of the device. According to this invention, apparatus for integrating an input signal incorporating a servo-mechanism having a servo-motor fed from a servo-amplifier 95 receiving the said input signal, to drive an output shaft, the angular position of which represents the integrand thereof, is characterized in that there is fed back to the servo-amplifier input, a corrective signal obtained from the algebraic additive combination of an input signal which is electrically derived from the position of the shaft of said servo-motor aid an output signal from an electronic circuit which also integrates said input signal over a limited amplitude range. In one form of the apparatus the corrective signal is obtained from a summing amplifier receiving both the ouput signal from the integrator circuit and the output signal derived from the position of the servo-motor shaft, which latter output signal is collected by the slider (driven by the said shaft) of a potentiometer which is annular in formi and which receives a reference D C potential difference across its terminals The routing of the output voltage from said sumiming amplifier to the servo-amplifier is controlled by means of a circuit-breaker actuated from the angular displacement of said shaft, said circuit-breaker cutting off said voltage from said path for any angular position of said shaft over an angular width at least equal to and registering with the inter-terminal gap of said potentiometer. Preferably two corrective signals are used, the second corrective signal being derived from a second integrator circuit and second

potentiometer which are identical with said first integrator circuit and said first potentiometer except for ail angular displacement relative to said shaft and being fed to the servo-amplifier when the first voltage is cut off by the said circuitbreaker. These and other features of integrating servo-mechanisms embodied in accordance with the present invention will now be described in detail with reference to the attached drawing, wherein:Fig 1 shows an example of such an integrating servo-mechanisn; Fig 2 shows an alternative part for such a servo-mechanism. In Fig 1, the input electrical signal which is the analogue of the variable from which must be obtained the integration value, is applied to the input teriminal 1 It consists of a signal of time varying amplitude without anv discontinuity, this amplitude remainin between two limits, for instance a positive limit and a negative one, any positive value of the variable corresponding for instance to a positive polarity of the input signal voltage and conversely any negative value of the variable being simulated by a negative polarity of the input voltage In the actual operation of a device according to the invention, the rate at which the amplitude of the input signal may vary will be the rate at which an input electrical signal may vary for a conventional electronic integrator circuit. From its input terminal 1, the said input signal O' is applied to the input of an integrating servo-mechanism and to both inputs of two integrator circuits. The integrating servo-mechianismn includes as is well-known, a servo-motor 4 fed from a servo-amplifier 3 and the input of said amplifier 3 receives the input signal through a series resistance? Upon the shaft of said motor 4 is set the rotor of a tachometer generator i 5, the generated voltage of which is fed back to the input of said amplifier:3 through the series resistance 6. The motor 4 is of a kind which may be driven both ways according to whether the current through its induction winding is of the one or the other direction That is why its connections have been shown with two leads In the drawings, the coinponents have been shown in mere conventional design, their practical interconnections being; made in accordance with the usual techniques. The shaft 7 is the driven shaft of the servo-mechlanismn Its angular position will at any time be a measure of the integral of the input variable. The first integrator circuit includes the high gain amplifier 9 provided with a negative feedback loop through a condenser 10 Its input receives the signal applied to 1 through a series resistance 8. The second integrator circuit includes the high grain amplifier 12 provided with a nceative feedback loop through a condenser 132 It

receives the input signal through a series resistance 11. The output of the first integrator circuit is connected to one of the input resistances, 16, of a summing amplifier i S provided with its own negative feedback resin=tance 19 The other one of the input resistances of said amplifier, I 7, receives an electrical voltage from the slider of a potehtiometer 14 This slider is driven by the shaft 7 Across the terminals 30) and 31 of this potentiometer is applied a reference unidirectional potential difference The voltage from said slider is at anv time instant proportional to the angular position of the shaft 7 and consequently simulates the variation of the value of the integral of the input variable as given by the integrating servoniechanism. The output of the second integrator eircuit is similarly connected to one input resistance 20 of another summing amplifier 22 provided with its negative feedback resistance 23 The other one of the 8; 5,61:. 7885,612 input resistances, 21, is connected to the slider of a further potentiometer 15 and said slider is driven by the shaft 7 of the servo-mechanism Across the terminals of said potentiometer 15 is applied a further unidirectional reference potential difference so that the voltage derived from said slider is at any time instant proportional to the angular position of the shaft 7 and thus simulates an electrical representation of the value of the integral of the input variable, as given by the integrating servo-mechanism. The direction of the potential difference across the terminals 30 and 31 of the first potentiometer 14 is so provided as to always be of the opposite polarity to that of the output voltage from the first integrator circuit The summing amplifier 18 delivers an output voltage which is always proportional to the difference, or subtractive combination, of these voltages on its inputs. In the same manner, the direction of the potential difference across the terminals 33 and 34 of the second potentiometer 13 is so provided that the voltage from its slider is always of opposite polarity to that of the output voltage from the second integrator circuit The suminig amnplifier 2,2 delivers an output voltage which always is proportional to the difference, or subtractive combination, of these voltages on its inputs. The output voltages from the summing amplifiers 18 and 22 are fed back to the servo-amplifier 3, via a feedback loop 37 and circuit-breakers 24 and 25 respectively The feedback loop 37 may either include a series resistance 26 as shown in Fig 1, or a series condenser 26 a as shown in Fig 2. Each of the integrator circuits includes a resetting arrangement which operates through a short-circuit of its feedback condenser This resetting is operated for the first circuit by means of a rotary

switch having its brush driven by the shaft 7 of the servo-mechanism, said switch comprising an insulating ring wherein is inserted a conducting block 27 This resetting is similarly operated for the second integrator circuit by means of another rotary switch having its brush driven by the same shaft 7 and also comprising an insulating ring provided with a conducting block 28 For instance the brush of a rotary switch is connected to the output of the corresponding amplifier and the block to the input of said amplifier. Each time a resetting occurs, the output voltage of the corresponding summing amplifier must be cut-off from the feedback loop 37 and, preferably, as will be hereinafter explained, these cut-off conditions cover a wider angular span that the one within which a resetting action occurs This is effected by the circuitbreakers 24 and 25 which may be of the rotary kind and controlled from the'shaft 7 70 The output voltages from said summing amplifiers also serve for controlling the actuations of the respective relays 29 and 32 in a manner which will hereinafter appear An actuation of such a relay pro 75 duces a change-over of its two contacts, viz from a potential condition on these contacts ( E,O) to the potential condition ( 0, +E) These contacts are respectively connected to the terminals of the potentio 80 meters 14 and 15 so that, for one of these conditions, these potentiometers will receive potential difference -E and for the other one, the potential difference + E (E being the reference voltage, equivalent 85 to the maximum value of the output of either of the integrator circuits, in either polarity). All the sliders and brushes controlled by the shaft 7 are supported by said shaft 90 in identical angular positions, whereas their stator components are divided in two groups, namely 27-14-24 and 28-1525, supported at 1800 from each other with respect to the axis of said shaft 95 The resetting to zero of the first integrator circuit will occur when the slider of the potentiometer 14 occupies a position within the gap 30-31, as the short-circuiting block 27 is provided ih correspon 100 dence to such an inactive range of displacement of the slider Further, for such an ineffective travel of the slider, the output of the summing amplifier 18 remains cut-off from the feedback loop 37, due to 105 the circuit-breaker 24. The resetting to zero of the second integrator circuit will occur when the slider of the potentiometer 1;o is within the dead angel thereof as the block 28 is 110 placed in correspondence with such a dead angle, and during this reset, the output voltage from the summing amplifier 22 will be cut off from the feedback loop owing to the operation of the circuit 115 breaker 25. By a " dead angle " of a potentiometer is here meant not only the rotational angle corresponding to the cut-off of the slider connection

between one teiminal and the 120 other, but in a broader meaning, the greatest rotational angle whereih the collected voltage cannot be accurate with respect to the manner in which the said potentiometer has been wound In an 125 arrangement according to the invention, and in order to ensure a high degree of accuracy of the answer of the complele system, such a dead angle may be taken as of a considerable value, for instance as 130 78; 5,612 great as 100 , without any drawback a corrective signal having a faithful value will always be supplied from the combination in response to the voltage collected by the slider of one or the other one of said potentiometers. For consideration of the overall operation of the above-described apparatus, the following denominations will be applied:o 0, for the input signal at 1; q 1, for the output signal from 9; to, for the output signal from 12; Al, for the voltage collected from the potentiometer 14; 012, for the voltage collected from the potentiometer 15; Ap= (fx q)j, for the output voltage from 18; and /\ 2 = ( 012-2), for the output voltage from 22. The integrator circuits are provided with the same characteristics and each one is so arranged as to present an integration slope via 1/CR, of a somewhat higher value than that of the integrating servomechanism C denotes the value of the condensers 10 and 13, R denotes the value of the resistances 8 and 11 The potentiometers 14 and 15, on the one part, and the summing amplifiers 18 and 22, together with their input and feedback resistances, on the other part, also are respectively provided with identical operafive characteristics. It may be assumed that the shaft 7 rotates in the direction of the arrow 3 a. w-hen the input signal is positive, and in the direction of the arrow 36 when said input signal is negative. Considering the system at rest in the condition shown in Fig 1, the input signal being zero In this condition, the relays 29 and 32 are such that their respecfive contacts apply: the reference voltage E to the terminals 31 of potentiometer 14 and 33 of the potentiometer 15; -the reference voltage O to the terminals of the potentiometer 14 and 34 of the potentiometer 15. An input signal O' is applied to the input terminal 1 of the system The variation of this signal according to time is quite an arbitrary one Assuming first that this signal is positive, the shaft 7 will rotate in the direction of the arrow 3; 3, SO do the sliders and brushes of the potentiometers and switches driven by said shaft. Both sliders of the potentiometers 14 and 13 will be driven in this direction At the same time, the output voltages from the two integrator circuits will also vary from 0 towards E Obviously the conditions of the relays must be changed in order that the summation

voltages A O and Aq, 2 are corrected so that the potentiometers 14 and 1 5 receive +E at their respective terminals 30 and 34 and 0 at their respective terminals:31 and:33. These changes will be automatically made 70 when the one and the other of the integrator circuits become reset. Relays 29 and 32 are such that they actuate their contacts when the voltage applied to their windings reaches a pre 75 determined value (operative threshold). When in the shown condition, they will be actuated when the output voltages from their respective control amplifiers reach +E In the reverse condition, of course, 80 they will be energised when said voltages reach E During the intervals of actuation, they remain in their set conditions. The technical means for obtaining such an operation of a relay appertain to the 85 art of controlling electromagnetic relays and for instance, each relay may have an energization winding in one direction and another energization winding in the other direction and these windings may be fed 90 through oppositely connected unidirectionally conducting elements, each relay winding passing through an auxiliary contact for self-maintenance of the relay once actuated to one condition and ampfitude 95 threshold defining means being provided in relation to their supplies through these respective unidirectionally conducting elements. Returning to the integrating system; 100 a whole, when the shaft 7 rotates in the direction 3 a 5 as has been assumed, the conducting block 28 will first be reached by the corresponding slider and the condenser 13 of the second integrator circuit '5 is then short-circuited This integrator circuit has its output reset to zero and will remain in such a condition as long as the slider remains on this block During this time interval, the slider of the potentio 110 meter 1-5 will have passed over the span from terminal '34 to terminal 33 so that the voltage on this slider becomes E. The summing amplifier 22 then delivers an output voltage +E and the relay 32 115 is thus actuated The armatures of said relay interchange their connections and the terminal 33 is earthed whereas the terminal 34 receives the voltage +E From this point, the slider of the potentiometer 120 will collect a voltage increasing from 0 to + E as the shaft 7 rotates, in the same direction 35 The second integrator circuit is correctly restarted at the same time and the output signal from 22 is then 125 correct. The xotation of the servo-meehanism shaft 7 in the direction M 3 will then effect the short-circuit through 27 of the condenser 10 of the first integrator circuit 130 7.85,612 The output voltage from 9 remains zero until the short-circuit is broken During this time

interval, the slider of the potentiometer 14 will pass over the gap between the terminals 30 aid 31 When reaching 31 at the very instant of restarting of the integrator circuit which is now concerned, the reference voltage -E is aplied to the input of 18 which delivers an output voltage + E, whereby the relay 29 is actuated The change-over of the armatures of this relay is operated and the terminal 30 of the potentiometer 14 now receives the reference voltage + E, the terminal 31 now receiving the earth-potential The first integrator circuit, having been reset, restarts from O Both the' output signals from the summlng amplifiers now are correct and will develop correctly throughout the normal operation of the device. If on the other hand, the servo-system in such a rest condition as shown receives a negative input signal at 1, the shaft is driven in the opposite direction, viz 36. When the slider of the potentiometer 14 reaches the terminal 31, assuming the width of the block 27 is equal to or less than the width of the gan 31-30, the summing amplifier 18 receives both a voltage E from the said slider and a -positive voltage from the amplifier 9 of the first integrator circuit Cohsequently no s-hange occurs in the supply of said potentiometer, as the relay 29 is not actuated: The first integrator circuit is reset to zero and the output signal from the summing amplifier 18 restarts from 0 Similar conditions are repeated for the resetting of the second integrator circuit, when the slider of the potentiometer 15 passes over the gap 33-34 whilst the second integrator circuit is reset and restarted If the width of the blocks 27 and 28 is made greater than the width of the gaps 30-31 and 33-34 the relays 29 and 32 will be twice actuated for restoring the initial conditions of supply of the potentiometers 14 and 15: a first actuation by E (alone in this case) hence a reversal of the polarity of the supply and a second actuation from +E (resulting from said first reversal) In either case, the device is automatically adjusted to its correct operative conditions. A similar analysis may be made from any other rest condition of the device and it will show that the maximum duration of establishment of correct operative conditions is that of a complete rotation of the shaft, the minimum duration being one-half of the first Once adjusted, the operation of the device includes an actuation of the relays each time a resetting occurs after a change of direction of rotation of the shaft 7. If necessary, the short-circuiting comlponents for the resetting to zero of the integrator circuits may comprise microswitch arrangements. In any case, there is obtained from the above described arrangement, a corrective signal in 37 which always simulates the positioning error of the integrating servomechanism with respect to the one or the other

of the integrator circuits The signal At is permanent and derived from the one andlor the other of the forming channels; an overlap may be avoided, if thought necessary, through a relative dimensioning of the annular rings of the circuit-breakers 24 and 25. The positioning error signal A O is, through the lead 37, routed towards the input of the integrating servo-mechanism. The corrected output signal Ho of this servo-mechanism will be obtained at any instant, representing:0 O= $( O Ao')t + through the application at the input of the servo-mechanism of a corrective voltage representing -AO in addition to the input signal po For ensuring such a correction, the corrective signal must be such that:-/0 dt= A 0. From the practical point of view, this correction will be ensured as shown in Fig 1, from the application of the signal AO, appearing on 37 in Fig 1 through 100 a mere resistance 26, provided said resistance has a value chosen with a suitable ratio, 1 /K with respect to the value of the other input resistance 2. For a more accurate correction, as shown 105 in Fig 2, the resistance 26 may be replaced by a condenser 26 a Denoting o the value of said capacity and R 1 the value of the resistance 2, the current applied for corrective purpose to the 110 input of the amplifier 3 is:d i= C-( A 0) It and the correction is:d R,.i= R, C 1 -(A 0) =-A O ' dt Of course, other corrective networks for 115 example more complex networks of resistances andlor capacitances may be used for obtaining more accurate corrections of the operation of the servo-mechanism, if a more accurate correction is thought 120 desirable.

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