An improved device for preventing cavitation in very high speed turbo-pumps for liquids

摘要

331,142. F÷ttinger, H. Sept. 18, 1929. Casings.-Cavitation is presented in high speed pumps by revolving coaxial frictional surfaces which are arranged in front of the suction mouth of the impeller and impart a preliminary rotation to the liquid. Rotating with the impeller 1, Fig. 1, is a number of conical surfaces 3 - - 5 secured to the rotor blades in any convenient manner and housed in an extension of the casing. In a modification the surfaces 3 - - 5 are connected by impeller blade extensions. In another modification a disc-shaped frictional surface 15, Fig. 3, is provided. The liquid enters the aperture 7, is rotated by the disc, and is led radially or obliquely inwards by the guiding device 16, 17 to the impeller 1. In the further modification shown in Fig. 4, the liquid is first accelerated by its passage between conical discs 15, 151, 1511, 15111 joined together by bridge pieces 18; the liquid is then led to the impeller eye by passages 16, 17.