Importance of Melt Pump Sealing in Polyester Plant

Melt pump is an important equipment in polyester plant. The seal of melt pump mostly adopts mechanical seal as filler seal. Because of the high melt temperature, easy deformation of spring and tine rings and the presence of impurities in the melt, mechanical seals usually have a short life of about half a year and high cost. Packing seal has fast wear and tear due to packing and bushing, and it needs to be packed under normal pressure, so it is difficult to replace. Therefore, mechanical seals and packing seals will result in increased maintenance workload and frequent replacement. Dry polyester production is a continuous production. The increase of maintenance volume brings great difficulties to safety production. The screw seal of melt pump seal is reformed. Through theoretical and practical experiments and practice, good results have been achieved.

The original packing seal is replaced by a combination seal structure of screw seal and oil seal, and the medium along the leakage gap is pushed back by reverse pumping of screw tip to realize the seal. And the use of oil seal letter as a secondary seal, can melt pump shaft seal without any leakage. This improved method only needs to modify the filler box, and has little change to the original structure, which can meet the sealing requirements and meet the limitation of the original structure with small available space.