4916 4920.output

* GB785323 (A)

Description: GB785323 (A) ? 1957-10-23

Improvements relating to motor vehicle fuel supply systems

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PATENT SPECIFICATION I Vefltors: JACK M WHITE and ALFRED 78 C KORTE Date of application and filing Complete Specification: Feb 15, 1955. No 4450/55. Complete Specification Published: Oct 23, 1957 Index at acceptance:-Classes 7 ( 3), B 2 G ( 8 B: l IC); and 135, P (ID: 24 lXX). International Classification:-FO 2 f G 05 d. COMPLETE SPECIFICATION Improvements relating to Motor Vehicle Fuel Supply Systems We, ACF INDUSTRIES, INCORPORATED, a Corporation organised and existing under the laws of the State of New Jersey, United States of America, of 30, Church Street, New York City, State of New Yorl, 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 described in and by the following statement: - This invention relates to an improvement in fuel supply systems for motor vehicles and the like, and more specifically to a novel fuel level control mechanism for a carburetor fuel bowl. In present designs, the maximum size of the needle valve and its seat is dictated by the size of the float which operates the needle valve

Float size determines the amount of force available to hold the valve on its seat against pump pressures At high ambient temperatures, excessive pressure can build up in the discharge line from the pump because of high vapour pressures due to boiling of the fuel These act directly on the valve, and, unless the valve remains effective, the carburetor and engine manifold will be flooded. Generally speaking, float size, and therefore buoyancy or float force, is not readily variable because of bowl size The exposed area of the needle valve is readily variable. Consequently, in order that the needle valve shall be effective at all pressures, the size of the needle valve must be such that the float force available is sufficient to maintain the valve in closed position against such pressure Often this requirement, imposed by conditions in the fuel system which cannot be changed, introduces a restriction in the supply of fuel to the fuel bowl of the carburetor and produces a throttling action in the discharge line from the fuel pump. Thus the fuel pump operation is impeded by limiting the length of its working stroke on the discharge, so that the pump is unable to lPrice 3 s 6 d l :5.323 fulfill its designed function and the supply of fuel is inadequate for engine operation The present invention consists in a motor vehicle fuel supply system for controlling the SO flow of fuel from a fuel pump comprising, a float-actuated needle valve for maintaining a predetermined constant fuel level in the float bowl of the carburetor during normal operation and a servo valve controlled by said 55 needle valve for permitting an increased fuel flow to the float bowl upon a drop in said predetermined fuel level. This mechanism eliminates the effects of restrictions inherent in needle valves, which 60 restrictions are responsible for vapour locking tendencies prevalent in most systems supplying highly volatile fuels under conditions of elevated air temperatures and in regions adjacent to sources of heat radiation 65 The modern motor vehicle furnishes a typical example of the above mentioned adverse conditions The fuel system therein must operate entirely within an environment of heated air passing through the radiator, 70 and over the engine and its exhaust system. The engine and exhaust, especially, are sources of high temperature radiation from which the fuel system is not protected. When the engine is operating, the effect 75 of heat on the pump, fuel lines, and carburetor makes it desirable that the valves in the system be as large as possible so that restrictions will not be present to impede the flow of large volumes of vapour 80 If the engine is stopped, it is desirable that the valves in the system remain closed even if the temperatures are high, and in spite of the occurrence of abnormal vapour pressures.

Since the forces available to operate the valve 85 against these pressures are necessarily light, the size of the valve is obviously limited in order that the force tending to close the valve will remain predominant When the float valve is small enough to remain closed 9 g under high fuel pressure, then it becomes a restriction creating back pressure on the Air pump discharge to restrict pump stroke after the engine is started Even though the float valve subsequently opens, it takes a certain amount of time for the vapour pressures to dissipate past this restriction This delay before the pump can reach full stroke in turn extends the period necessary for the pump to exhaust the vapours on its suction side and fill the fuel lines As a result, the engine is starved for fuel and either stalls or fails to deliver its full power. Since the present valves do not meet these conflicting requirements, pressure reducers have appeared on the market which are designed for connection between the pump and the carburetor float valve These devices, however, are, in themselves, restrictions, and only one aspect of the problem presented is solved by their use Being restrictions, the tendency of the system to vapourlock is increased by their use. In the present invention, the main fuel supply is under the control of a large diaphragm actuated servo valve The pressure in the fuel lines is by-passed around this valve so as to act upon the back of the diaphragm to force the valve closed Communicating with the chamber in which the diaphragm is mounted is a pressure relief passage controlled by a needle valve in the carburetor. When the needle valve is closed, the diaphragm operated valve is forced closed by the pump pressure in the fuel supply line which operates upon a diaphragm of an area much larger than that of the valve Thus, the higher the pressure in the fuel supply line, the tighter is the seal effected between the diaphragm actuated servo valve and its seat. When the needle valve relieves the pressure on the diaphragm, the diaphragmactuated valve can open, allowing the fuel to enter the float bowl of the carburetor through a passage independent of the needle valve, and accordingly unrestricted by the limited size of the needle valve passage The servo control effected by the needle valve can be performed regardless of its size. SO Since the main fuel supply is by way of the passage controlled by a diaphragm actuated servo valve, the restriction of needle valve passage has no effect upon the capacity of the system for the obvious reason that the S servo valve can be any size The size of the servo valve can be independently selected so as to immediately dissipate any vapour pressure in the pump discharge The pump can start operating

simultaneously with the 6 o engine, at full stroke to fill the fuel lines The usual delay in pump operation is avoided. In the accompanying drawings:Fig 1 is a diagrammatic view of a motor vehicle fuel system, Fig 2 is a view showing partly in section the needle and servo valves according to this invention, as a part of a standard carburetor; Fig 3 is a fragmentary sectional view showing both the needle valve and the servo valve open; and 70 Fig 4 is a fragmentary sectional view similar to Fig 3 illustrating another phase in the operation of the device. Figs 5 and 6 are views in section of modified forms of the invention 75 Fig 7 is a view in side elevation of the outside of the casing shown in Figs 1 to 4, inclusive. In Fig 1, an engine 1 is shown having an exhaust manifold 2 and an intake manifold 80 3 A carburetor 4 is mounted on the vertical riser 5 of the intake manifold 3 and provided with the usual heated jacket connected to the exhaust manifold 2 A combined fuel pump and suction booster pump 6 is mounted on 85 the side of the engine to be operated from the engine camshaft The fuel pump end is connected by a line 8 with the fuel tank of the motor vehicle and by a line 9 with the carburetor 4 The suction booster end of 90 the combined device 6 is connected by a line with the intake manifold and by a line 11 with the suction operated accessory devices of the motor vehicle. Turning now to Fig 2, a fuel valve accord 95 ing to the present invention is disclosed as formed integrally with the carburetor The carburetor itself has an air horn 12, a float bowl 13, and a throttle body 14 interconnected in assembled relation Within the float 100 bowl 13 is a float 17 mounted on an arm 18 pivoted at 19 As shown in this particular construction, the pivot 19 is supported from a bracket 20 integral with the float bowl cover 22 The latter is secured to the float 105 bowl by a series of cap screws 23 and 24. Formed integral with the arm 18 is a finger 25 bearing directly against one end of a needle valve 26, which operates as a pilot valve Guide 27 supports the needle valve 110 for vertical movement to and from a suitable valve seat A passage 29 leads from the seat to a chamber 30 which is connected by a passage 32 with the main fuel supply passage 33 by way of a metering orifice 34 The size 115 of the float valve seat is so selected as to be much larger than the metering orifice 34, so that pressure can be immediately relieved below the diaphragm 36 when the float operated valve 26 opens a substantial amount 120 Diaphragm 36 supporting the servo valve 37 is secured in position on the float bowl cover by a cap 40 having a chamber 41 surrounding a valve seat 42 Cap 40 contains parts of passages 32 and 33 above described, and is 125 also provided with a passage 45 extending from the chamber 41 and connecting through the diaphragm 36

with the auxiliary fuel supply passage 46 leading to the fuel bowl. The diaphragm actuated servo valve 37 is 130 785,323 In Fig 5 is shown a fragmentary section of a float bowl 50 closed by a cover 51 Within the float bowl is a float 57 having arms 56 hinged on a pin 55 supported by a depending boss 54 from the cover 51 A finger 59 70 formed integrally with the arms 56 extends upwardly to a position whereby movement of the float 57 upwardly will cause the finger 59 to be moved to the right Float bowl has a boss 52 provided with a threaded 75 opening 53 The opening 53 is suitably positioned with respect to the finger 59 so that the needle valve assembly usually mounted therein may be actuated by the finger 59. According to this embodiment, the needle 80 valve customarily supplied with the carburetor is removed and a control valve unit comprising both the needle valve and the servo-operated valve, substituted therefor. The casing 63 of the control valve accord 85 ing to this invention its threaded at 64 for engagement with the threads 53 in the boss 52. Within the casing is formed an axial passage 79 receiving the needle valve 61 and its operating stem 60 The stem is so po'si 90 tioned in the casing and passage 79 as to be in alignment with the finger 59 of the float arms 56. With the structure so far described, the control valve unit is properly positioned so 95 that movement of the float 57 vertically within the fuel bowl 50 will operate the needle valve 61 against its seat 62 to close off the passage of fuel through the seat 62 into the axial passage 79 100 A diaphragm 67 is secured between the casing 63 and a cover 66 Attached to this diaphragm 67 is a servo valve 68 A spring 65 is interposed between the diaphragm 67 and the casing 63 to force the servo valve 68 in 105 a direction to close the passage 69 Threads in the passage 69 provide for connection with the fuel pump discharge line. Servo valve 68 controls communication between the passage 69 and the passages 77 110 and 78 which, in turn, connect with the axial passage 79 through the casing 63 This system of passages provides the auxiliary fuel supply and is much larger than the passage through the needle valve seat 62, thus en 115 suring that when the valve 68 opens, any pressure in the pump discharge line connected at 70 will be immediately dissipated If the discharge line happens to be full of vapour, valve 68 will remain open as long 120 as the float is lowered and the needle valve 61 is off its seat Thus the pump discharge line is quickly vented and the pump can re. sume its full stroke immediately to fill the fuel lines with liquid from the tank 125 In order that fhe needle valve 61 may control the action of the diaphragm actuated servo valve 68, passages 72, 73 and

74 lead around and through the diaphragm 67 Within the passage 73 is a restriction which will 130 urged towards a closed position by a coil spring 49 between the diaphragm and the needle valve guide 27. In Fig 2 the parts are shown in position S with the needle valve 26 closed and the servo valve 37 closed In this position pressure from the fuel supply passage 33 is effectively cut off by the servo valve 37 by pressure of fuel below the diaphragm in the chamber 30, which communicates with the passage 33 by way of the passage 32. So long as the needle valve or pilot valve 26 remains closed, the pressure within the chamber 30 exerts a force over an area much larger than the valve 37 to maintain this servo valve tightly closed, and this will remain the case regardless of fluctuations of pressure in the fuel supply line 33. When the degree of opening of the needle valve, caused by excessive drop in the level of the float 17, exceeds the size of restriction 34, as shown in Fig 3, pressure in chamber 30 is relieved Reduced pressure acting on diaphragm 36 will allow fuel pressure in the line 33 to open servo valve 37 and enter the float bowl 13 The valve 37 is of large diameter and easily forced from its seat by the fluid pressure acting against spring 49. The amount of fuel entering the float chamber is therefore not restricted by the size of the float operated valve 26, but finds an unrestricted entry past the servo valve 37 Consequently, any vapours which are trapped in the fuel line are readily dissipated into the carburetor bowl, and thence to atmosphere or through a vent to the mixture conduit of the carburetor, if provided. The size of the restriction 34 may be suitably selected to produce any desired response of the servo valve 37 to the needle valve 26. For example, it might be deemed desirable for the valve 26 to have a capacity sufficient for normal low speed operation of the engine or for idling speed, so that the servo valve would open only at high engine speed or to vent large accumulations of vapour The action of a structure so designed is illustrated in Fig 4 of the drawings In this view needle valve 26 is open sufficiently to supply the normal engine requirements of fuel but not far enough to remove the pressure from beneath the diaphragm 36 for the valve 37 to open It is clear therefore that the operational frequency of the servo valve 37 is limited The selection of the right size restriction and needle valve to produce any result deemed desirable in the action of the servo valve is contemplated. The construction so far described relates to an embodiment which is constructed integral with the carburetor or with the float bowl cover for the carburetor It is possible, however, to apply the invention to existing carburetors and Figs 5 and 6 illustrate devices for this

purpose. 785,323 cause a pressure drop in the passage 74 and, therefore, on the left side of the diaphragm 67 when needle valve 61 open's a substantial amount. S With the structure so far described, excessive movement of the needle valve 61 o ZA its seat 62 immediately relieves the pressure on the diaphragm 67 holding the valve 68 closed Under these conditions, pressure on the valve 68 will immediately compress the spring 65 and open the auxiliary supply passages 77, 78 and 79. Conversely, w vheni needle valve 61 closes, the pressures on opposite sides of the dial S plhragm 67 will immediately equalize, closing the valve 68 due to the difference in area betveen the diaphragm 67 and the exposed surface of the valve 68, and the pressure exerted by the spring 65 By these means passage of fuel past this valve 68 will be resisted regardless of the amount of pressure exerted by the spring 65. Slight openings of the needle valve 61 which do not appreciably reduce the pressure on the left side of the diaphragm 67 will be permitted without opening movement of the servo valve 68 Accordingly, small amounts of fuel may be continually supplied by the opening of the needle valve 61 for normal operation of the engine. Fig 6 shows a similar construction to G that in Fig 5 In this embodiment, the usual needle valve seat which is mounted within the fuel supply opening 80 is removed and the control valve structure substituted therefor The casing 81 of this structure is threaded at 82 to be received within the opening 80 for the usual needle valve seat. Casing 81 has a normal fuel supply passage 88 receiving a needle valve 84 operated from the finger 85 integral with the float 86 and its arms 87 Needle valve 84 controls the passage 88 which connects with the lefthand chamber formed by the diaphragm 90 with casing 81 A cover 91 seals the edges of the diaphragm against the casing 81. Within the cover 91 is the main fuel supply passage threaded at 92 to receive the supply line from the engine driven fuel pump Passages 93, 94 and 95 connect with the passage 88 controlled by the needle valve 84 Passage 94 contains a restriction 96 of less capacity than the passage 88. A fuel by-pass is controlled by a servo valve 100 riveted to the diaphragm 90 and normally spring pressed into engagement with the end of the nassage 92 by a spring 101 Passage 102 is threaded at 103 to receive a suitable fitting which, in turn, connects with a line 104 to an auxiliary opening in the fuel bowl This latter opening may be drilled or formed on an existing opening at any location in the bowl wall, for drainage or inspection of the fuel level. The device operates in the same manner as above described.

Fuel pumps now Generally used ia motor vehicle fuel systems are no- in a sense, of the positive dispilacement type Tine diaphragm type of pumxp drivaen iron the enrine is actu 70 ally spring powet on its discharge stroke so that fuel cipszhr Pressures will not be excessive and rupture tb; wirraem Electricaily driven puior' no in a neros use in the fuel Sv Sel,-IS c' moior v 'icles a e Cther 75 of the sam type operated by sprint,oer on the disciarge stroke or are centr'uaal pumps navin G a pressure relief providing a li ited discharge pressure c" the fuel. T Asts performed on fuel s'stems equipped 80 with this improved control valv is ae shown a mnai ed F ir p r in puirr capnziy for handling engine fuel requirinemnts at extreme temperatures It is believed tlat this imoro-vement in pump capacity can be ex 85 plained by the fact that valve action in the presence of liquid fuel is different than under conditions of mi xed flow of fuel and vapour. Under the first condition, the opening of the needle valve will usually be gradual 90 This is due to the fact that the fuel passing the needle valve will tend to retard the rate of drop in float level. When liquid fuel and vapour flow conditions exist, fuel level in the float bowl has a 95 tendency to drop faster due to the lack of flow of liquid fuel past the needle valve Accordingly needle valve opening is more rapid, and it is this action of the needle valve which is responsible for opening the servo 100 valve and so giving the pump an opportunity to operate at full stroke against the de, creased resistance imposed by the resulting low static head In anv case, pump operation is definitely improved under these flow 105 conditions. It will be understood that when the servo valve opens, any vapours in the discharge line will be rapidly dissipated into the float bowl, and thence by vent into the mixture 110 conduit of the carburetor.

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* GB785324 (A)

Description: GB785324 (A) ? 1957-10-23

Improved process for coating titanium or titanium alloy with aluminium or analloy thereof




PATENT SPECIFICATION 7 g 959324 Inventors:-ERIC HOLMES, DAVID PUGH and TREVOR BROO Ml. Date of filing Complete Specification: Feb 15, 1956. Application Date: Feb 21, 1955 No 5082155. Complylete Specification Published: Oct 23, 1957. Index at Acceptance:-Classes 82 ( 2), G( 2 A: 2 H:3:14 E: 15 E); and 83 ( 1), F 16 (A 124: B 2 D). International Classification:-B 22 d C 23 c. COMPLETE SPECIFICATION. Improved Process for Coating Titanium or Titanium Alloy withAluminium or an Alloy thereof. We, POWES JETS (RESEARCH AND DEVELOPMENT) LIMITED, a British Company, of 25 Green Street, London, W 1, do hereby declare the invention, for which we pray that a patent may be granted to 1 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 coating titanium or titanium alloy with aluminium or an aluminium alloy to form a protective surface which will serve to prevent oxidation of the titanium. The object of the invention is to provide an improved process for coating titanium or titanium alloy by immersing an article with a titanium or titanium alloy surface in molten aluminium or alloy thereof. The invention is based on the discovery that a thin coating of an organic liquid such as glycerin applied to a titanium or a titanium alloy surface before immersion in molten aluminium or alloy thereof enables a satisfactory protective coating of aluminium or alloy to be formed on the titanium or titanium alloy surface.

According to the invention, the surface of an article made of titanium or titanium alloy is prepared with an adherent film of an inert vaporisable high boiling liquid carbon compound, for example, a high boiling aliphatic hydroxy compound such as a dihydric or polyhydric alcohol, and is then immersed in molten aluminium or an alloy thereof, for a period of time sufficient to heat the titanium or titanium alloy article to the temperature of the molten metal and is finally withdrawn from the said molten metal, whereby the surface of the article of titanium or titanium alloy, as the case may be, becomes clad with lPrice 3 s 6 d l a protective coating of aluminium or alloy thereof. In a preferred method of carrying out the invention, the titanium or titanium alloy surface of the material or article concerned is first cleaned free from oxide and then coated with a film of glycerin, after which the said surface under treatment is immersed in molten aluminium or aluminium alloy, for a short period, for example, about 30 seconds at a temperature between 750 and 8500 C, and thereafter removed and allowed to cool. In practice the process may be carried out according to the following description, given by way of example The titanium surface is rendered free from oxide, for example, by a grinding operation and is then degreased in a known manner Next a thin layer of glycerin is applied to the surface which is then given a final cleaning using an abrasive such as emery Excess of glycerin is removed together with emery particles and another coating or film of glycerin applied to the surface The prepared titanium surface is then rapidly immersed in a bath of molten aluminium or an alloy thereof, according to choice, for a period of time sufficient to heat the titanium to the temperature of the bath. The duration of this treatment will vary with the specimen and the bath dimensions, but usually about 30 seconds or a little more at 760 C is adequate. The effect of the glycerin seems to be to protect the titanium surface from oxidation or other attack before immersion in the aluminium bath, and to disperse any aluminium oxide which may be drawn into the molten bath around the titanium and which would prevent contact between the twyo metals After immersion, the molten bath 81) Price -'S C-' C? 785,324 provides the necessary protection to the titanium against oxidation or other undesirable contamination during heating. The process of the invention is also a applicable to articles which consist of titanium alloys containing a relatively high percentage of titanium Thus, samples of titanium alloys have been hot-dipped in "Duralumin "as hereinafter described The word " Duralumin " is a Registered Trade Mark Some of the alloys used consisted mainly of

titanium (between 88 and 95 per cent by weight) with small percentage weights of: ( 1) manganese; ( 2) aluminium 1.5 and tin ( 3) iron, chromium and molybdenum; ( 4) aluminium, iron, chromium and molybdenum; or ( 5) aluminium and vanadium; the total amount of the other metals ranging from 5 per cent to 12 per cent. Strips of the titanium alloys were cleaned free from oxide and coated with a thin film of glycerin and dipped in molten " Duralumin " alloy at a temperature between 8000 and 8500 C for periods between two and five minutes, and then withdrawn leaving a uniform thin coating of " Duralumin " on the surface of the titanium alloy. Liquids such as glycerin are superior to a solid or semi-solid inorganic flux for the dipping operation, as such fluxes cannot protect the titanium or titanium alloy surface until they become molten at a relatively high temperature Moreover, such iluxes usually leave behind a black deposit which gives rise to an uneven coat, whereas material such as glycerin volatilises and burns away completely without leaving a residue. The properties of glycerin which render it especially suitable for the process are that it is liquid between room temperature and 29 Oo C, and non-reactive towards titanium in this region It boils below the temperature of the molten bath, and the gases evolved disperse any undesirable aluminium oxide. Moreover, it burns completely without residue. Other organic compounds may well be satisfactory, but few of these readily available possess such a wide liquid range as glycerin. One such alternative is ethylene glycol. For cladding operations in which a thicker layer of aluminium or its alloy is required, the dipped titanium or titanium alloy may be transferred from the molten bath into a horizontal or vertical mould which is then filled with molten aluminium or aluminium alloy before the dipped layer has time to solidify.


* GB785325 (A)

Description: GB785325 (A) ? 1957-10-23

Improvements in or relating to the manufacture of chromium-free steel




IB A-TENT SPECIFICATION 785,325 Date of Application and filing Complete Specification March 2, 1955. No 6199/55. Application made in Germany on April 3, 1954. Complete Specification Published Oct 23, 1957. Index at Acceptance:-Class 72, D 3 G( 11: 2 A 2: 7 MI 2: 7 N 1), 1 DS(A 1 D 2). International Classification: COMPLETE SPECIFICATION lm prov-rem ents' E or 'tela to the Mnnufagclture of ChromiumFree Steel We, WESTFALENHUTTE Arx TIENGESELLSCHAFT, of Eberhardstresse 12, Dortmund, Germany, a German company, 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: Lateritic iron ores make up a considerable part of the world's iron ore deposits, according to present knowledge For example, the lateritic ore's are widely distributed in the region of the Equator and particularly in Africa, e g Gonakry ores Despite their purity as regards phosphorus and sulphur and their frequently relatively economically suitable position, they play a quite subordinate role in iron ore smelting The essential reason for this is the chromium always present in iron laterites In smelting, the lager part of tie chromium goes into the pig iron Relatively small chromium contents in pig iron, e g over 0.20 %, can lead to considerable difficulties in the manufacture of steel, especially soft steel, since

chromium is only oxidised in the course of the refining process and the oxidation products of chromium, chromite or chromium spinel, because of their extremely high melting points, only separate with great difficulty from the steel bath The manufacture of steel in the usual way from chromium-containing pig iron usually leads to material contaminated with chromium oxides, which is hence of low value. A method is known for producing mild steel or steel from chromium-containing pig iron, in which, by employing additional metal oxides before, during or immediately after the furnace or air refining, such amounts of mangatlese or iron oxides, e g sinter scale, are added to the melt that the chromium content decreases to less than 0 06 % In particular, in this known method, in air refining, the iron oxide required for slagging the chromium is obtained by over-refining the bath This method has not been introduced into steel lPrice 3 s 6 d l manufacturing practice, since the chromium can only be removed by over-oxidising the steel This results in economic and metallurgical disadvantages since the yield of iron is 50 decreased by extremely high iron contents in the slag and the steel is excessively enriched with oxygen. It is also known to refine pig iron before the actual steel manufacturing process The pur 55 pose of this pre-refining is to lower the manganese, silicon and inter aria the vanadium contents of the pig iron This gives rise to the possibility of removing silicon from poorly blowable pig iron of high silicon content 60 and/or to recover a part of the manganese and/or vanadium. The present invention relates to a method for manufacturing chromium-free steel from chromium-containing lateritic iron ores by 65 smelting the ores in the blast furnace and refining the pig iron in an open hearth furnace or Bessemer converter According to the invention, the chromium-containing iron ore is mixed with othcr iron ores so as to produce 70 a pig iron containing over 0 2 % chromium, below 0 8 % manganese, the usual content of phosphorus and the usual or increased content of silicon, whereupon the chromium content of the pig iron is decreased by oxidative refin 75 ing in the presence of heat-absorbing oxides to below 0 1 % and the low chromium pig iron is then subjected to a refining process to form chromium-free steel The oxidative refining to remove chromium is effected by the 80 addition of heat-consuming gaseous, liquid or solid oxides to the blowing medium or to the bath and the process is preferably carried out at a temperature not greater than 1350 C, due to the considerable cooling effect of the 85 added oxides Blowing can be effected either with air, oxygen-enriched air or pure oxygen, since regulation of the temperature is feasible by the additions of the heat-absorbing oxides. The oxidation is performed so that with 90 appropriate temperature

regulation the chromium content is reduced below 0 10 %. 785,325 Vanadium, together with silicon and manganese, is formed into slag The carbon content of the pig iron is not substantially affected. After the oxidation, the slag is removed and the pig iron is further refined in the usual way, e g by blowing in a Bessemer converter with a pre-refined pig iron added to it. By the method of the invention, particular advantages are given not only in blast furnace operation but also in steel works There is considerable flexibility in the slagging and temperature control in blast furnace operation. The usually important silicon content, e g for the quality of Thomas pig iron, no longer imposes any Iimitation It is reduced to an extremely low value by the oxidation process. Chromium evolves more heat on oxidation than corresponding amounts of manganese It is therefore possible for the otherwise undesirable chromium in the pig iron to replace a part of the heat of oxidation of manganese in the process It has been found, in particular, that chromium oxide-containing slag produced by the oxidation of chromium is crumbly rather than thinly liquid at the temperatures concerned This has the advantage that the chromium-containing slag can be readily withdrawn from the metal bath. In Thomas works, the pig iron produced and treated in accordance with invention gives a particularly easily blowable iron which facilitates the obtaining of a low nitrogen content in the steel. The process of removal of chromium from the pig iron by the invention can be carried out in the runner, ladle or mixer or in steel manufacturing process, e g in the converter. It is advantageous for the converter to be acid lined and for the oxidation to be carried out without the addition of lime. A preferred embodiment of the method of the invention is given below By smelting chromium-containiing lateritic iron ores, e g. Conakry ore with ca 1 to 2 % of chromium, with the addition of other iron ores, a pig iron is produced having a chromium content of e g 0 80 % The manganese content amounts to about 0 60 % This pig iron is refined in the ladle by blowing in oxygen and the addition of roller mill scale (Fe,O) The chromium content was reduced to below 0.10 % The manganese content decreased to 0 20 % The silicon and vanadium in the pig iron passed over almost completely into the slag The slag so produced contained approximately 25 % of Fe, 20 % of Mn, 6 % of Cr and 3 % of V, the slag analysis in round figures being:32 % 26 % 9 % 4 % 18 % 3 % 2 % 4 % % i 00 % Fe O Mn O Cr 2 O, Vo, G 23 Si O,. Al,0, Na 2 O+K 20 Pao M Ca O+Mg O Such a slag is suitable for the manufacture of special steels, e g chromium-vanadium steels or chromium-manganese-vanadium steels, in an electric furnace for

instance, since these metals can be readily reduced again in 75 the metal bath The chromium-free pig iron was then blown to steel in a Thomas converter and had a nitrogen content of 0 004 %.


* GB785326 (A)

Description: GB785326 (A) ? 1957-10-23

Method for the production of pneumatic stowing tubes

Description of GB785326 (A)

COMPLETE SPECIFICATION Method for the Production of Pneumatic Stowing Tubes We, Q;EWERgscHAFT REUSS, of 48, Bredeneyerstrasse, Essen, Germany, a Joint Stock Company, organized and existing under the laws of the German Federal Republic, 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 invention relates to the production of tubes for pneumatic stowing or other hydraulic or pneumatic conveyance of bulk material, which consist of a welded or seam- less sheet steel tube within which a wearresistant chilled cast iron lining is produced by means of the centrifugal casting method. It is known that the pneumatic stowing tubes do not become uniformly worn over the entire length of the individual tube sections, but that considerably more wear occurs in the vicinity of the inlet end, i.e. viewed in the direction of conveyance of the bulk material, after the point of connection of the tubes. The considerable wear which occurs in this zone of the tube wall renders the tubes prematurely unusable.

It has now been found that premature wear at the inlet end of the individual pneumatic stowing tubes can be avoided by formin the chilled cast iron lining in the individual tube sections so as to extend advantageously conically from the inlet end to the outlet end thus providing a smaller free cross-section cf passage at the outlet ends of the tubes than at the inlet ends. This special construction of the chilled lining can be obtained by the centfffugal casting method according to the present invention by suitably adiusting the speed of rotation pf the chill mould or sheet metal casing in which the chilled lining is formed, the density of flow of the liquid cast iron and the speed of advance of the pouring spout or lip with respect to the chill mould or casing whilst the molten metal is being poured in. The operation is advantageously begun by pouring in the liquid cast iron at the wider end, for example using high speeds of rotation, and then the speed of rotation of the chill mould or casing is reduced whilst the pouring spout is gradually advanced in the direction towards the outlet end of the tube section as the material is poured in. By this means the casing tube is formed with a chilled lining thickened in the direction towards the outlet end either with a uniform taper over its entire length or with a taper over part of its length, the remainder being of uniform diameter. Two embodiments of the invention will now be described with reference to the accompanying drawings of which: Fig. 1 is a section through a tube having a fully tapered lining, and Fig. 2 is a section through a tube having a partly tapered lining. In both forms of the tube shown in the drawings, a sheet metal casing 1 having welded-on collars 2 is provided with a chilled cast iron lining 3. The direction of flow of the material to be conveyed by being passed through the tube is indicated by the arrow 4. It will thus be apparent that the ends 5 and 6 are respectively the input and output ends of the tube. In the embodiment of Fig. 1, the thickness of the lining 3 increases uniformly from the inlet end 5 to the outlet end 6. In other words, the lining is conical with a constant taper throughout its length. In the embodiment of Fig. 2, the conical portion of the lining 3 only extends between the outlet end 6 and an imaginary vertical plane 7. The remainder of the lining is substantially cylindrical. The tapered portion may conveniently be approximately one third the length of the cylindrical portion. Thus if the tube section is three metres long, the conical portion would be approximately one metre in length. The conical portion is produced by gradually reducing the speed of rotation from that required for forming the cylindrical portion so the thickness of the lining is progressively increased. In order to make a smoother transition between the outlet end 6 of one tube and the inlet

end 5 of the next tube, the speed of rotation may be increased again as the pouring spout reaches the outlet end. What we claim is: - 1. A method for the production of pneumatic stowing tubes or the like which consist of a sheet steel casing tube and a chilled cast iron lining produced therein by a centrifugal casting method, characterised in that by adjusting the speed of rotation of the casing tube, the density of flow of the liquid cast iron, and the speed advance of the pouring spout whilst the molten metal is being poured in, the inside of the casing tube is formed with a chilled lining which is thickened in the direction towards the outlet end of the tube. 2. A method according to Claim 1, characterised in that the chilled lining is substantially cylindrical over part of its length while the remander of its length is formed with a taper whereby the lining is increased in thickness in the direction towards the outlet end. 3. A method substantially as described and claimed hereinbefore with reference to the accompanying drawings.

* GB785327 (A)

Description: GB785327 (A) ? 1957-10-23

A protective relay for a 3-phase alternating current distributing system

Description of GB785327 (A)

PATENT SPECIFICATION 785,327 Inventors:-LIONEL OAKLEY DEACON and HARRY STANLEY LEWIS. Date o filing Complete Specification: March 2, 1956. Application Dale: April 7, 1955 No 10216/55. Conibplete Specification Publisited: Oct 23, 1957. Index at Acceptance:-Class 38,5), B 1 RB, Bl R 1 S(C E F), K( 1 A 2 A: 22). International Classification:-H Olh. COMPLETE SPECIFICATION. A Protective Relay for a 3-Phase Alternating Current Distributing System. We, CHAMBERLAIN & HOOKHAM LIMITED, of 4 New Bartholomew Street, in the

City of Birmingham 5, a British Company, LIONEL OAKLEY DEACON and HARRY STANLEY LEWIS, both of the Company's address, and both British Subjects, 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 a protective relay of the so-called negative phase-sequence type, for a 3-phase alternating current distributing system, the relay being adapted to initiate the actuation of a circuit breaker or other device in the event of an inter-phase or other fault in the system. In the Specification of our application for Patent No 720,020, we have described and claimed a relay for the above mentioned purpose which comprises the combination of a movable switch-actuating armature, electromagnetic means comprising there pairs of windings adapted to exert a torque in one direction on the armature, each pair including a reactive winding and a resistive winding which when excited by currents derived from the system to be protected produce a torque proportional to the product of the currents, the said pairs of windings when the apparatus is in use being supplied with currents from different pairs of lines in the system, and the resistive winding in each pair being connected in parallel or series with a reactive winding in another pair; and additional electromagnetic means adapted to exert under normal working conditions torques which are equal and opposite to the first mentioned torques, the opposing torques lPrice 3 s 6 d l being proportional to the square of their exciting currents. In the above described relay certain of the windings are defined as reactive and resistive, in the sense that the impedance of one of the windings in each pair is predominantly reactive and that of the other winding is predominantly resistive. The present invention has for its object to enable both windings in each pair to be predominantly reactive, and for this purpose the invention consists of a modification of the apparatus above described wherein each of the windings in each pair is reactive and one is energised through a current transformer such that the phase of the current in the secondary winding is displaced relatively to that of the current in the primary winding by 1500. One example of a relay which embodies the modification is illustrated by the drawing accompanying the Provisional Specification In general the relay shown in the drawing is similar to that illustrated in our above mentioned Specification It consists of an armature formed by three coaxial discs a', a', a', all mounted on a common spindle b which at one end carries a contact arm c co-operating with fixed

contacts d in the trip-circuit of a circuit breaker or other device In association with the armature disc a' and at opposite sides thereof are arranged two electromagnets f', g' both of which have a predominantly reactive impendance Similar electromagnets f 2, g 2, f, g' are arranged in asociation with the other armature discs a'2, a' respectively The windings of the electromagnets fl, f 2, f 3 are respectively excited by current transformers h 2, h', h' on the phases 1, 2, 3 of the dis785,327 tributing system The windings of the electromagnets g_, g 5, g 3 are excited by currents supplied by the secondary windings of the current transformers k', k 2, k 3. Each of the above pairs of electromagnets is adapted to exert on the associated armature a torque in one direction To produce the counterbalancing torque, an additional electromagnet il P, P is provided in association with the armatures In the example illustrated the winding of the electromagnet P is excited by current supplied from the transformer h' through the primary winding of the transformer k 1, and the winding of the electromagnet if Likewise the winding of i 2 is excited by current supplied from the transformer h' through the primary winding of the transformer k 5, and the winding of the electromagnet f, s and the winding of P is excited by current supplied from the transformer h 2 through the primary winding of the transformer k 5, and the winding of the electromagnet fl. The transformers k', k 2, k 5, may, however, be arranged in a variety of other positions, and moreover the windings of the electromagnets g-,,g, i 2 and g 3, P may be connected in other ways of which the following are examples. The windings g', i', may be conencted in series with each other and with the secondary winding of the transformer k', the primary winding of this transformer being in series with the winding of the electromagnet f, and the windings of the electromagnets acting on the other armatures are connected in like manner. In another arrangement, the transformers k', k 2, k 5 are each provided with two secondary windings in which case one of these in the transformer k' excites the winding of g', and the other the winding of il and so on for the other electromagnets. In a further arrangement, the winding of the electromagnet i 2 serves as the primary winding of k', and on f is provided the secondary winding of k' which is connected in series with the winding of the electromagnet g', and so on. In a still further arrangement, transformers k 1, k 2, k 5 are Drovided as shown in the drawing, and current is supplied to the windings of il i 2, i from secondary windings on the electromagnets f, fx, f respectively. Instead of providing separate electromagnets gl, i 2 _ 2, -, 'g,

equivalent single electromagnets may be used, each having two interconnected iron limbs carrying separate and oppositely wound windings. In all cases, the currents supplied by the transformers k', k 2, kli, are such that the phase of the secondary current of each is displaced relatively to the primary current 1500, and this displacement may be obtained for example by providing in the associated iron core an air gap of appropriate width.


4916 4920.output

Law