Institute of Fluid-Flow Machinery
Polish Academy of Sciences

Abstract

In large multistage pumps the axial thrust is balanced mostly by a balancing device composed, in general case, of a drum and disc. Several years ago the authors proposed the energy optimization method for the design of such a system enabling to minimize the leakage and disc friction losses. In this report the influence of the following factors on the optimalization results is discussed:
– adopted method of non-linear programming,
– various geometrical dimensions,
– magnitude of clearances,
– pressure drop and velocity across the clearance between the disc and its opposite ring,
– accuracy ofevaluation ofaxial thrust and of respective coefficients used in calculations.

The method proposed by the authors has been introduced into the design practice in Poland.