Abstract
This paper defines certain proposed positive-displacement-blower efficiencies in Equations [1], [2], [3], [5] in terms of slippage air, i.e. (1 — vol. eff/100), which is taken as a means for rating the design of the blower. Equation [6] may be used to obtain ns which is defined as the “slip” polytropic-compression exponent. The first example showsactual details of computation of optimum rotor-bore diameter and axial length for a given delivery volume, speed, impeller clearance, and head based on the methods given by K. Schopper. The volumetric efficiency for the given blower design is then compared with that of the optimum-design blower. These results are then applied in Equations [1] and [2]. In the second example volumetric efficiency is plotted against the ratio of axial length to bore diameter with conditions fixed as in the first example. These results may be applied to Equations [1] and [2].