Design Of Magnetically Driven Chemical Pump To Fit ANSI B73.1 Dimensions Using A Semiopen Impeller

Abstract

A magnetically driven sealless chemical pump was developed that employs high torque rare-earth magnets. Utilizing a semiopen impeller configuration, the pump was designed to fit into the ANSI B73.1 standard dimensional envelope. This was done to simplify retrofitting the existing installed pump population or, in the case of new installations, the piping design; thus, standard existing NEMA motors, couplings, bedplates, pump impellers, and casings can be used. Through the use of a nonmetallic containment shell, eddy currents were eliminated, and the pump efficiency was within two points of that of a comparable conventional pump with a mechanical seal. A metallic containment shell was developed for the relatively small number of applications in which the non-metallic shell is not suitable. The implementation is discussed of the development program for this sealless pump, including the shell, the thrust bearing needed for the semiopen impeller and the encapsulation with both metallic and nonmetallic materials of the driven magnets.