Abstract: A system for simultaneously degassing and pumping a liquid from a source includes in combination a gaseous liquid source having a feed inlet for the liquid so as to form a liquid surface at a first level; a degassing pump for simultaneously degassing and pumping the liquid, the degassing pump includes a housing with a liquid inlet, and an outlet for a substantially gas-free flow and a gas discharge opening, a suction conduit having a first end connected to the pump inlet and a second outlet immersed in the liquid below the liquid surface. Preferably, the suction conduit is immersed in the liquid flow below the liquid surface and below the feed inlet.

Abstract: A method of separating an aqueous solids containing suspension includes (a) subjecting a first solids containing suspension to centrifugal forces so as to separate the suspension into a first gas containing flow, a second gas-free flow and a third flow; (b) feeding the third flow into a flotation cell having a bottom; (c) introducing air at the bottom of the flotation cell into the third flow for separating from the third flow a fourth partial flow; (d) withdrawing the air containing third flow after the separation of the fourth partial flow from the flotation cell; and (e) subjecting the third flow to the centrifugal forces of step (a).

Abstract: An arrangement for attaching a machine element to a shaft, especially for impellers of pumps, comprises a spiral-formed key which is firmly fixed to the shaft, with the element to be attached being provided with a corresponding keyway.