... h, 6000Nm3/h, 10000Nm3/h, 28000Nm3/h. The air is only the material used in the plant. The ... producing the pure oxygen and nitrogen from the air with a method of medium pressure cycle and ... cryogenic refrigeration i. e. first product the liquid air using the medium pressure recitrocating expansion engine, then in ... the cold box, the liquid air is rectificated into gas oxygen with a purity ...