Performance Comparison of Slurry Pumps with Secondary Impeller Seals and Packing Seals

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• TIME : 2025-05-30

Structure composition and working principle

Secondary impeller seal: The system consists of two parts: the secondary impeller and the packing. During the operation of the slurry pump, high-pressure liquid from the impeller outlet enters the secondary impeller flow channel through the gap between the impeller cover plate and the rear guard plate. At the same time, due to the rotation of the secondary impeller, the liquid in the flow channel forms a liquid ring with a certain thickness to achieve a sealing effect. Packing sealing is mainly set up to prevent leakage after the pump is shut down. The sealing of the secondary impeller relies on fluid dynamic action for sealing, which belongs to non-contact sealing. Air or clean water generates pressure under the rotation of the secondary impeller, and forms an air slurry or water slurry balance with the slurry on the outer edge of the secondary impeller, thus resisting the leakage of liquid at the outlet of the main impeller.

Packing sealing: Insert soft packing into the packing box (stuffing box), press it tightly with a cover, and seal it against the cylindrical surface of the shaft or shaft sleeve. The basic requirement is to inject pressurized clean water (called shaft seal water) through the shaft seal water hole, and the pressure should be greater than the outlet pressure of the pump. The function is to seal off the leakage of slurry and prevent air from entering the pump chamber, which is particularly important for suction pumps.

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(Editor in charge: Slurry Pump https://www.fuyangpumps.com/)

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