초록 ▼

An improved pump for efficient operation at low flow rates to avoid undue power consumption and heating of the fluid being pumped. There is provided a centrifugal pump including a housing with an inlet. A radial or mixed flow discharge impeller is rotatably mounted within the housing and an outlet v

An improved pump for efficient operation at low flow rates to avoid undue power consumption and heating of the fluid being pumped. There is provided a centrifugal pump including a housing with an inlet. A radial or mixed flow discharge impeller is rotatably mounted within the housing and an outlet volute extends about the impeller. First and second axially spaced diffusion passages establish fluid communication between the impeller and the volute and a valve is provided for closing one of the passages when low flow rates are demanded of the pump to minimize recirculation, leakage and churning losses consuming the power and leading to heating of the fluid.

대표청구항 ▼

A centrifugal pump comprising: a housing; an inlet for said housing; a radial or mixed flow discharge impeller rotatably mounted within said housing; an outlet volute extending about said impeller and spaced radially outwardly therefrom; at least one first relatively large diffusion passage establis

A centrifugal pump comprising: a housing; an inlet for said housing; a radial or mixed flow discharge impeller rotatably mounted within said housing; an outlet volute extending about said impeller and spaced radially outwardly therefrom; at least one first relatively large diffusion passage establishing fluid communication between the periphery of said impeller and said volute and having an end adjacent said impeller; at least one second relatively small diffusion passage axially spaced from said first passage and establishing fluid communication between the periphery of said impeller and said volute; and valve means between said impeller and said first passage(s) for selectively opening or closing said end(s) of said first passage(s).