GB658843A - Improvements relating to centrifugal pumps, air or other compressors and the like - Google Patents

Abstract

658,843. Centrifugal pumps and compressors. BELLISS & MORCOM, Ltd. Dec. 14, 1948, No. 32274. [Class 110(i.)] The exit end of each of the passages between the blades of the impeller is made of nozzle-like form which is determined by a pair of mutually inclined side surfaces, the radial extent of which is determined by the intersection with the front surface of an impeller blade of a line drawn at rightangles thereto from the tip of an adjacent blade. In one construction, Figs. 2 and 3, the inner surface of the side walls g of the impeller are substantially parallel over a region h, and are mutually inclined over a zone i to form the discharge nozzles. Preferably, the blades comprise long blades j alternating with short blades k. The inner boundary o of the zone i is determined by dropping a perpendicular n from the tip of a blade k to an adjacent blade j. Modifications are described in which one side wall g is omitted and blades are formed on one or both sides of the remaining side wall, the adjacent casing wall or walls being shaped to form one or both of the inclined walls of the nozzles. In an alternative construction, the short blades k are omitted and, whilst the outer faces of the side walls g are symmetrical, the portions of the side walls between the blades j are progressively thickened from the front face t of any one blade to the rear face u of the next blade, as shown in the developed view shown in Fig. 8. The side edges of the front face t correspond to the lines 2, 3, Fig. 7, and the side edges of the rear faces u correspond to the line 4. Fig. 9 shows a construction in which the impeller side walls g are parallel or slightly inclined over the region ahead of the nozzle zone, but in the zone are formed with inwardly inclined depressions s.