the drive system for cells for fused salt electrolytic production of aluminum is supplied with compressed air via a compressed air network with compressor and compressed air reservoir . it comprises at least one working cylinder with piston and piston rod , a slide valve situated after the junction from the compressed air network , compressed air pipes and a microprocessor . during the thrust movement in the normal work cycle , the working cylinder forms a circuit together with a 5 / 2 channeling valve , a 3 / 2 channeling valve and the related compressed air pipelines ; the said circuit is fed compressed air via a pressure reducing valve and the compressed air pipeline running from it . by briefly switching over the 5 / 2 channeling valve normal pressure can be employed and the positive chamber of the working cylinder evacuated , as a result of which the thrusting force supplied by the system can be greatly increased .