| dc.description.abstract | Sealless pumps are now specified as the preferred type for handling of toxic, hazardous, and environment threatening chemicals. Magnetically driven sealless pumps have emerged as the first choice, due to their simplicity of design and ease of maintenance. Much is written of the importance of pump/system interaction in ensuring maximum pump life. Inside of the sealless magnet drive is a complex internal flow system which is difficult to model, but is crucial to the successful operation of this type of machine, due to the need to effectively cool the magnetic drive, lubricate the bearings, and safely transport solids. With low specific heat, volatile liquids, a clear understanding of the internal flow system is essential if dangerous flashing resulting in premature pump failure is to be prevented. The results of tests undertaken on a number of different internal feed systems are presented. Plexiglas models, flow visualization, and pressure profile analysis were all carried out to provide a solution to give optimum performance under widely varying pump conditions. The interaction of the main internal flow path with that to the bearings is also reviewed. It is hoped that a clearer understanding of the inner workings of sealless machines will allow closer cooperation between the supplier and the customer in applying these types of pump correctly to fluids of various characteristics with maximum success. | en |
