How to improve the mechanical seal of high temperature gear pump

High-temperature gear pump for the transmission temperature of 250 degrees above the booster device, it compact structure, the lucky antelope reliable, low energy consumption, high volumetric efficiency, small shear on the melt, in the high viscosity, high pressure flow Stable, no pressure fluctuations in exports. In spite of this, the mechanical seal leakage caused the pump down to 45 times, causing direct economic losses of up to nearly 1 million yuan. In spite of this, high-temperature gear pumps also have shortcomings. Due to the continuous operation of high-temperature medium, the sealing liquid can not be operated during the installation of the mechanical seal, and the gear pump body temperature can reach up to 310 degrees, causing the graphite wedge ring to expand rapidly. Sealant investment, the machine cavity temperature decreases, wedge ring contraction, which led to mechanical seal leakage. For those mechanical seals that have been replaced due to leakage, hydrostatic tests were carried out to find that the wedge ring between the revolving rings was the main factor causing mechanical seal failure. This structure and mechanical seal on the maintenance staff of the installation of higher level requirements in the installation process is not easy to accurately locate, resulting in moving ring deflection, leading to seal leakage. Shrink ring deformation of the mechanical seal is the pump is small, the main reason to cancel the wedge ring to make it integrated with the sleeve, can achieve the goal of leakage. Re-processing of the sleeve, directly on the boss sleeve flange welding metal corrugated sheet, and then inlaid moving ring. The axial and radial dimensions of the collar are sprinkled over the axial distance and the radial dimension of the thrust collar. At the same time, in order to facilitate the disassembly of components, additional grooves in the root of the sleeve and fitted with the corresponding retainer. Eliminate the main point of leakage, before the improvement, the average mechanical seal life of about 8 months. After the improvement, the mechanical seal runs smoothly and the failure rate is obviously reduced. Over the past year, only changing the seal five times, radically reducing emissions.