Patent ID: 8870521

Claim:
A centrifugal pump for delivering hot fluids, comprising: a contacting shaft seal disposed in a region of a shaft lead-through; a seal housing for the shaft seal, and a return line for a partial flow of the delivered hot fluids, wherein no said delivered hot fluids is discharged from the seal housing; a separate housing cover is disposed between the seal housing and a pump housing of the centrifugal pump; a contact surface between the seal housing and the separate housing cover minimizes heat transfer; a relief device for axial thrust provided upstream of the contacting shaft seal is configured to form a cavity between the relief device and the separate housing cover through which the partial flow of the delivered hot fluids passing the relief device are discharged via the return line; the return line is separate from a hot fluids delivery outlet of the pump housing; and an end of the return line that receives the partial flow of the delivered hot fluids from the cavity is formed within at least one of the separate housing cover and an outer wall of the pump housing.