Multi-stage centrifugal pump i.e. two-stage centrifugal pump, for conveying easily outgassing or combustible fluid with low boiling point, has pump stage compensating axial thrust of suction impeller that comprises suction-side gap sealing

摘要

The pump has a suction impeller (5) with a suction-side gap sealing (10), and a subordinate stage impeller (9.1) with a pressure-side gap sealing (11.1). A pressure-side impeller cover disk (17) is provided with relief openings (15). The hydraulic design of the suction impeller corresponds to that of the stage impeller. The suction impeller is designed without an axial thrust relieving mechanism. A pump stage (8) compensates axial thrust of the suction impeller. The diameter of the pressure-side gap sealing is greater than that of the suction-side gap sealing.