The Medium Conveyance

Regarding the supply and removal of the medium to be pumped by the front surfaces of the respective compressor stage, one distinguishes single-sided and double-sided pressurised machines. 

But to some extent, one also guides the medium to be pumped from one to the other front face of the compressor stage. In addition, one inter casing with a suction port and another inter casing with a pressure port are needed. 

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For reasons of economy and also for reasons that are historically developed, primary vacuum pumps with inter casings have prevailed in the industry up to now. Deformations of the impeller and inter casing rotationally symmetrical to the shaft centre are conceivable for the enlargement of the working openings. Conical and cylindrical hubs are already completed constructions (Figure 3.7). The possibilities of the medium conveyance discussed in the earlier details as well as the design of the pressure ports are also transferable to the employment of these control bodies. 

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