摘要 |
A feed pump with a variable-speed drive for adjustably metering a feed quantity, which is designed as a single-stage centrifugal pump with a radial wheel arranged to rotate, without a sealing gap, in an impeller chamber of a pump casing, to convey a fluid between a pump inlet and outlet. The radial wheel is connected to a variable speed drive motor having a five-digit rotational speed range, receives the flow centrally, is provided with feed ducts, and has an outside diameter of up to 50 mm, while the centrifugal pump is designed for partial-load operation, the feed quantities of which range from 0 to 3600 ml/min with lifts of 20 to 300 meters. The inside diameter of the impeller chamber is at most 4% larger than the outside diameter of the radial wheel. A seal is arranged between the impeller chamber and the radial wheel or its shaft, and the circumference of the impeller chamber is provided with one or more outlet ducts arranged at an acute angle or tangentially to the outside diameter of the radial-wheel.
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