The reason of vacuum failure of water ring vacuum pump

As one of the common equipment of dehydration parts in paper mill, water ring vacuum pump can be used for suction water tank and vacuum roller to draw water in the paper. The working principle is: before starting the water ring pump, water ring is formed at the rim by rotating the cylindrical impeller after the start-up. Because the cavity shell of the pump body is oval, the water ring rotating with the impeller wheel will be pushed in and out in the impeller chamber, resulting in vacuum and pressure transmission.

After two or three years of use, the vacuum suction capacity of water ring vacuum pump will be decreased. There are also some problems in the vacuum suction capacity of many 2BV water ring vacuum pumps used in a paper mill. Later, the whole vacuum pump was disassembled and inspected, and the reason for its failure was finally found.

1. many cavitation pits of different sizes and shapes are formed on the blades of impeller, which are more serious in the rim part, and the largest cavitation pit can reach 60 × 15 × 30mm3.

2. the tolerance of the matching between the elliptical cavity shell and impeller of the pump body becomes larger.