| 摘要 |
1510846 Axial-flow pumps ITT INDUSTRIES Inc 15 July 1975 [23 July 1974] 29602/75 Heading F1C An axial-flow pump for liquid, e.g. sewage, containing solids and long fibres, comprises diffuser vanes 8 extending inwardly from the pump casing downsteam of the impeller 2 and having sweptback leading edges which are at not more than 70 degrees and preferably 40-50 degrees with respect to the pump axis, a central space 9 having a diameter at least 10% of the casing internal diameter being formed within the inner tips of the vanes, and the impeller hub having a smooth prolongation 6 of hemispherical or frusto-conical form. The closest approach of the prolongation 6 to the leading edges of the vanes 8 is at least about 10% of the casing internal diameter. The hub diameter and the blade tip clearance of the impeller 2 are about 50% and 6%-10% respectively of the casing internal diameter. An elongate bearing 5 shields the driving shaft to prevent elongated objects, e.g. rope and string, from becoming wrapped around it. |
