JPS5654992A - Centrifugal impeller - Google Patents

Abstract

PURPOSE: To improve the efficiency of an impeller by maintaining the relative speed distribution in an impeller in a good form, in a centrifugal impeller having a low specific speed and a small exit angle of the vane wheel.

CONSTITUTION: The shape of the meridian surface of an impeller is widened toward end in the vicinity of te exit of the impeller. Namely, in the shape of the meridian surface, a core plate 2 is formed into rectilinear form and the side plate 3 is formed into circular arc. As a result of this, the width b₂ of the exit is larger than the width b_m of the intermediate part of the flow pasage. Due to the shape of the meridian surface flow passage, the sectional area of the flow passage at the intermediate part of the flow passage reduces, and the speed on the meridian surface increases. On the other hand, in the vicinity of the exit, the sectional area increases relatively, and the speed on the meridian surface reduces. Accordingly, the relative speed distribution becomes desirable in which the speed reduces continuously and monotonously from the inlet of the impeller to the exit, and the minimum value is not form midway in the average speed.

COPYRIGHT: (C)1981,JPO&Japio