SYSTEM FOR EXCLUDING PROCESS FLUID AND SOLIDS FROM SEALS AND BEARINGS OF AN AXIAL PUMP IN A LOOP REACTOR

摘要

A mechanical expelling mechanism for an axial pump system in a loop reactor includes straight or curved repelling vanes mounted to a vertical or tapered rear face of the impellor hub and a tapered wall provided in the adjacent seal housing. In combination, these elements exclude and eject process slurry, especially polymer solids, away from the seals and bearings, and thereby prevent damage to the seals and bearings, at least until a flow of flushing fluid can be restored. The repelling vanes further serve to circulate and exchange any process fluid and catalyst that remains in the space between the impellor and the seals, so that localized warming and run-away formation of polymer solids near the seals is avoided. The repelling vanes can be curved or straight. In embodiments, the repelling vanes reduce pump efficiency by less than 1 %.