What kinds of filters do mechanical seal adopt when introducing flushing

Flushing is an important part of auxiliary facilities of mechanical seals.There are some problems such as impurities occuring when flushing is in operation.

Some media in production contain solid particles. Even if the media is clean, some impurities will enter the system from the outside when the device is shut down for overhaul. Once it enters the sealing end face of the mechanical seal, it will destroy its sealing performance.There are three types of filters currently used: screen filters, hydrocyclones, and magnetic filters.

Y-type filter is a kind of screen filter with simple structure and low price. It can be directly connected to the pipeline of the mechanical seal device. After clogging, remove the screw plug and take out the filter screen to clean it, and the proportion of mechanical impurities is not limited. The disadvantage is that the pump needs to be stopped to release the pressure during cleaning. Hydrocyclone: In order to overcome the shortcomings of the Y-type filter, a hydrocyclone has emerged. The medium containing impurities enters along the tangential direction of the separator and rotates along the separator at a certain speed. Using the difference in specific gravity between solid particles and liquid, the clean liquid flows out from the top of the separator to flush the seal, and the liquid containing impurities flows back to the pump from the bottom entrance. The separation effect is related to factors such as liquid viscosity, solid specific gravity, solid viscosity and content, pressure difference between the inlet and outlet of the separator, and the separation efficiency can reach more than 95%.

The effect of the hydrocyclone is better in the following range. The solid content does not exceed 10%; the specific gravity of the solid should be greater than that of the liquid; the maximum viscosity of the liquid does not exceed 2o~25 centimeters; the ratio of the difference between the inlet pressure P1 and the clean liquid outlet pressure Pc and the difference between the inlet pressure P1 and the dirty liquid pressure Pd is 0.8~ 1.2.

When the specific gravity of mechanical impurities of the mechanical seal device is lower than or close to the specific gravity of the medium, the hydrocyclone cannot be used. Magnetic filter: There are several sets of magnetic elements inside, separated by polytetrafluoroethylene backing rings, which can absorb impurities around the magnetic poles. Its structure is complex and needs to be cleaned regularly. Two points should be paid attention to when using this filter. One is that the magnetic rings are attracted together in pairs during assembly, and each pair is separated by a flat gasket, and the magnetic rings separated by the gasket must repel each other; the second is that it can only be used in Where the mechanical impurity is a magnetic material.