A C O K E OVEN G A S - O X Y G E N S C A R F I N G T O R C H M A C H I N E

A. D . Z y k o v , G. I . M a r t ' y a n o v , a n d M. I . S o k o l o v

The MOZ-2-KMK-SMI machine for flame scarfing surface defects uses a KVOZ-64-SMIscarf ing torch with a V-shaped nozzle having a cross section of 3 X 150 mm at the outlet . This torch provides unifarm scarfing and high meta l surface qual i ty . However, it requires a comparat ive ly high quanti ty of oxygen. To reduce the consumption of oxygen in scarfing, a new nozzle design was developed,

The nozzle (Fig. 1) is a flat slot type with outlet dimensions of 3 x 150 mm and consists of two copper plateso To the upper plate at an angle of 30 ~ is welded a tube for supplying the cutting oxygen, The lower plate has a s tamped cavi ty of e l l i p t i ca l shape for improved distribution of the flow and for equal iz ing the pressure of the jet both inside the nozzle and at its outlet . The distance from the slot of the nozzle to the center of the cavi ty is 0.8 times the length of the nozzle .

The sides of the liner, sandwiched between the plates, are straight and at the inIet end there is a notch surround- ing the oxygen tube.

The KVOZ-65-SMI scarfing torch head was also developed (Fig. 2). In the new design cutter the nozzle is placed between the tips and is connected with the frame of the head by bolts. To protect the scarfing torch :from melt ing it is equipped with a water cooled screen. The shape of the tips was changed, but the dimensions of the ducts for preheating the coke oven g a s - o x y g e n mixture remained the same as in the l<VOZ-64-SMI scarfing head, 33 2.5-mm holes in each t ip.

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UO

Fig. 1 Fig. 2

Fig. 1. The nozzle for cutting oxygen: a = the small axis of tae ellipse; ~. = the lengm of the nozzle, 1 and 2) sides of the nozzle; 3) tube for supplying oxygen; 4) stamped e l l ip t i ca l - shaped part; 5) l iner .

Fig. 2. The KVOZ-65-SMI coke oven g a s - oxygen scarfing torch: 1 and 2) tips for supplying the coke oven g a s - o x y g e n mixture; 3) nozzle for the cutting oxygen; 4) flange of the scarfing head frame; 5 and 6) tubes for supplying the coke oven g a s - o x y g e n mixture; 7) tube for supplying the cutting oxygen; 8) water -cooled protective screen.

Siberian Metal lurgical Institute. Kuznets Metal lurgical Combine. Translated from Metallurgo No. 12, p~ 33, December, 1971.

�9 1972 Consultants Bureau, a division of Plenum Publishing Corporation, 227 ~'est 17th Street. New ]

York, N. Y. 10011. All rights reserved. This article cannot be reproduced for any purpose whatsoever l

without permission of the publisher. A copy of this article is available from the publisher for $15~00, l I 2

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TABLE I, Results of Machine Scarfing 40-Steel Billets

Scarfing head Cutting [Slot dimensions, [=~ .=~ IOxygen con- I sumption, ox en ~-~" Yg ,I mm 1 ~ . ~ [ mS/h under pressure - - - - r - - - - - - - t o ~ ~ I normal atm thickness t width ]~ ~ ~ ] conditions

KVOZ-64-SM[ 0,7--0 ,8 l , O - - t , 5 210 9,5 520--540 1,1--1,2 t ,0 - -1 .8 210 19,2 540--580

KVOZ-65-SMI 0,6--0 ,7 1,0--1,5 210 19,2 400--420 0 , 9 - - I , I 1,5--2,5 210 19,2 420--450

Table 1 shows comparat ive results of testing new and old design scarfing heads under shop condtions inscarf ing 210 x 210 mm bil lets of 40 steel. As the tab le shows, the consumption of oxygen with the new design scarfing head is reduced by 25-30%. The KVOZ-65-SMI scarfing head operates under the following conditions:

Coke oven gas pressure, a tm Oxygen pressure before nozzle, a tm Consumption of coke oven gas, m3/h under normal conditions Consumption of cutting oxygen, m3/h under normal conditions Width of the cut, mm Depth of the cut, mm Scarfing speed, m / m i n

a 210

0.9-1.2 0 .6 -1 . ! 60-70

400-500 180-210 0.5-2.5 Up to 20.0

Production tests have shown that the KVOZ-65-SMI provides uniform scarfing and makes it possible to scarf • 210 mm bi l le t in one pass with high qual i ty cleaning of the surface and the absence of skin.

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