Abstract: A screw-centrifugal pump (1) comprises a pump housing (3) having an inlet opening (3c) and also an impeller (2) arranged within the pump housing (3) and rotatable about an axis of rotation (2d) in a direction of rotation (4a). The impeller (2) has a spirally extending blade entry edge (2a) and a guide vane (5) projects into the interior space of the impeller (2) and is disposed in the region of the inlet opening (3c). A method of conveying a liquid permeated with solid additions using such a pump is also described and claimed.

Abstract: A screw-centrifugal pump (1) comprises a pump housing (3) having an inlet opening (3c) and also an impeller (2) arranged within the pump housing (3) and rotatable about an axis of rotation (2d) in a direction of rotation (4a). The impeller (2) has a spirally extending blade entry edge (2a) and a guide vane (5) projects into the interior space of the impeller (2) and is disposed in the region of the inlet opening (3c). A method of conveying a liquid permeated with solid additions using such a pump is also described and claimed.

Abstract: The impeller (1) is seated with its impeller hub (3) fixed for rotation on a shaft (4). The drive-side edges of the impeller (1), turn with slight clearance (a), over a pump-housing rear wall (5). The latter forms a labyrinth slot 6) with the impeller (1). The labyrinth slot (6) connects the pump chamber (2') with a hub chamber (7). Within the hub chamber (7), a coaxial vane wheel is connected, fixed for rotation, with the impeller (1) in order to impart a stronger rotary movement to the liquid in the hub chamber (7) and centrifuge it. The hub chamber (7) is provided with a peripheral opening (12) for the emergence of the liquid. The air collecting in the region of the shaft (4) escapes through a slot (10) which is formed by the hub housing wall (20) and the shaft (4).

Abstract: The housing wall (23) through which the impeller shaft passes is embodied as a truncated cone. The leading edge (28) of the impeller blade flank (27) on the delivery side of the pump which grazes this housing wall with little clearance (24) extends in a spiral from the impeller blade tip (35) up to a point (31) at which it terminate in the hub; as a result, a relatively large area of the housing wall (23) having a width b decreasing toward the inside and located between the blade flank on the delivery side and the blade flank on the intake side is exposed between the blade outlet tip (35) and this terminal point (31).

Abstract: A centrifugal pump for conveying liquids with deposited solids has two grooves winding in opposite directions around the impeller axle from the inside to the outside, one groove being in the radial annular surface of the sealing cover of the pump housing and the other in the impeller hub. These surfaces rotate relative to each other and are separated from each other by a leakage gap. The radial inner wall of each groove forms a shearing edge with the adjacent annular surface and the grooves open outwardly towards the surge chamber of the pump housing and inwardly towards a central leakage-collecting chamber. The collecting chamber is connected to the cooling jacket of a pump motor and an outlet leads back to the suction inlet of the pump. Water penetrating into the leakage gap cools the motor and solids penetrating into the gap are separated by the shearing edges from the annular surfaces and forced back to the pressure side of the pump by the grooves.

Abstract: A centrifugal pump which has a single-blade impeller and is used particularly for the transport of long-fibered deposited solids, for example, in sewage. The pump impeller discharge end lies in a radial plane adjacent a housing wall there being a clearance between the housing wall and the discharge end. The blade face is directed to the housing wall to form an acute angle with that wall, the line between the outer extremity of the blade and the discharge end of the blade forms an acute angle relative to the axial direction of the impeller. The front edge of the impeller is sharpened and provides a moving shearing edge, and the housing wall provides a stationary shearing edge so that medium pumped into the impeller can be cut and disintegrated between these edges. The angles defined facilitate drawing the long-fibered solids into the area for shearing and disintegration.

Abstract: The present invention is directed to a centrifugal pump of the type including an essentially conical rotor having a helical vane increasing in diameter from its entrance end to its discharge end; the peripheral edge of the vane confronting the wall of the pump housing and forming with the pump housing a discharge or pressure chamber and an intake or suction chamber, the peripheral edge of the vane diverging from the wall of the pump housing from the discharge chamber toward the intake chamber, and having minimal clearance with respect to the wall of the discharge chamber side of the vane.

Abstract: An automatic volume control for centrifugal pumps wherein a centrifugal pump is arranged with its suction oriface facing downwardly into an open top tank having a tangential feed channel. The tank is placed in a receiver for the liquid to be pumped, at a level wherein the tank and the feed channel is submerged below the intended maximum liquid level. An upwardly directed air line outlet may be placed in the bottom of the tank in axial alignment with the pump.