【正文】 opriate changes in the blasting sequence, which is difficult to do in practice, or to screen the shot during operation of the machine to provide the specified particle size. Stability in the blasting process is also determined by the quantity of shot delivered to the nozzles. It was experimentally established that supplying kg/sec of shot to the two nozzles in operating with an air pressure of atm provided stable operation. Equipping the machine with screening devices is an effective method for maintaining a constant shot size mix. This is confirmed both by data in the literature and by experience in the operation of SM1 and TsKb_P1 shot blast machines at Zaporozhstal Plant. The shot is delivered to the surface of the roll by the shot blast equipment, the chamber of which is divided by two diaphragms with charging vents into three partments and is equipped with an electropneumatic control device. The working mixture from the upper partment of the chamber drops to the lower and then to the collector. During operation of the machine,the vents are closed (turned on). The shot is poured in either after turning off the valves by the electropneumatic control device, or after shutting down the machine by the operator. When it is turned off, the vent descends, and between it and the diaphragm a circular gap 5 mm wide is formed. The vent is a cone with a slope of about 30% The shot drops slowly through this gap but not pletely, and therefore it increases to t0 ram. The loading vents are alternately turned on by the control device. The first time the SM2 machine was repaired, it was discovered that the control device frequently did not operate because of corrosion of the parts. With normal charging of abrasive (375 kg according to the nameplate), blasting must be stopped after each alternate pass of the nozzles, since after another pass the shot in the lower partment is insufficient, and during blasting, With nonoperation of the control device, it does not drop from the upper partment to the lower. Delivery of the nextportion of shot must be done only after the operator disconnects the shot blast equipment from the air system. In this case both charging vents are opened, and the abrasive is fed to the lower partment. Continuous operation of the machine for three or four passes of the nozzles with nonoperation of the control device and the delivery of shot described above became possible after increasing the standard charge to 650 kg. However, the basic solution of this problem is stable operation of the control device. The used shot is collected by the collecting bunker of the working chamber and drops into 4 the receiving chute of the worm conveyor. The plates parallel to the worm conveyor are at a greater angle, and those perpendicular are at less of an angle, which tends to collect shot on them. Therefore, after blasting one roll it is necessary to shut the machine down to push the accumulated shot on to the screw conveyor. To eliminate this shorting, it is possible to lengthen the screw conveyor, which is half the length of the working chamber. In addition, the smaller plate is removed pletely,and the parallel plates are elongated to correspond with the length of the worm conveyor. The pressed air supplied to the collector of the shot blast equipment is dried by an oil