Improvement of mechanical seal for polyester high temperature melt pump
The polyester high temperature melt pump provided by Zhengzhou Bart has the advantages of compact structure, reliable operation, low energy consumption and high volumetric efficiency. The high temperature melt pump has little shearing effect on melt, the most stable flow at high viscosity and high pressure, and no pressure fluctuation at the outlet. It plays an irreplaceable role in polyvinegar production. The pump shaft seal adopts double end bellows mechanical seal.
The shortcomings of polyester high temperature melt pump: because the production of polyester is continuous, the sealing liquid can not run during the installation of mechanical seals, and the temperature of gear pump body reaches 310 degrees Celsius, resulting in the rapid expansion of graphite wedge ring. After the sealing fluid is put into use, the temperature of the sealing chamber is reduced, and the wedge ring is contracted, thus causing the leakage of the mechanical seal. Static pressure tests were carried out on the mechanical seals replaced by leakage. It was found that the wedge ring between the moving ring and the sleeve was the main factor causing the failure of the mechanical seals.
Improvement of the structure of polyester high temperature melt pump: The shrinkage deformation of the tine ring is the main reason for the failure of the mechanical seal of the high temperature melt pump. The purpose of leak control can be achieved by canceling the wedge ring and integrating it with the sleeve. The axle sleeve is re machined, and metal corrugated sheets are welded directly on the surface of the convex ring of the axle sleeve, and then the dynamic ring is embedded. The axial and radial dimensions of the convex ring depend on the axial distance and radial dimension of the thrust ring. At the same time, in order to facilitate assembly and disassembly of components, concave planting (groove width 3 mm, depth 3 mm) is added at the root of the sleeve, and corresponding clamping springs are installed.