Mechanical seal internal and external flushing methods and characteristics

The purpose of mechanical seal flushing is to prevent the accumulation of impurities, to prevent the formation of air pockets, to maintain and improve lubrication, etc. When the flushing fluid temperature is low, it also has a cooling effect. The flushing methods are mainly as follows.

A, mechanical seal flushing within　

1, positive flushing (1) characteristics: the use of the work of the host of the sealed medium, from the export side of the pump through the pipeline into the seal cavity.　　(2) Application: for clean fluid, p1 slightly larger than p into, when the temperature is high or impurities, can be set in the pipeline cooler, filter, etc..　　

2, backflushing (1) characteristics: the use of the work of the main body of the sealed medium, introduced into the sealing chamber from the outlet end of the pump, flushing through the pipeline back to the pump inlet.　　(2) Application: used to clean the fluid and p into.

3、Full flushing (1)Characteristics: Using the sealed medium of the working host, introduced into the sealing chamber by the outlet end of the pump through the pipeline, and then flow back to the pump inlet through the pipeline after flushing.　　(2) Application: cooling effect is better than the first two, for clean fluid, and p1 and p in and p out when close to each other.　　

Second, mechanical seal external flushing　　

Features: Introduce clean fluid compatible with the sealed medium from the external system to the seal cavity for flushing.　　Application: External flushing fluid pressure should be larger than the sealed medium 0.05 - 0.1MPa, for the occasion that the medium is high temperature or solid particles. The flow rate of the flushing fluid should ensure that it takes away heat and also needs to meet the flushing needs without producing erosion of the seal. To achieve the above flow rate value, the difference between the flushing liquid and the seal chamber pressure should be<0.5MPa, generally 0.05 - 0.1MPa, for double-end mechanical seals can be 0.1 - 0.2MPa. Flushing liquid into and Discharge the location of the orifice of the seal cavity, should be set near the seal face, and should be near the dynamic ring side, in order to prevent graphite ring erosion or temperature deformation caused by uneven cooling, as well as the accumulation of impurities and coking, etc., can be introduced tangentially or multi-point flushing. If necessary, the flushing fluid can be hot water or steam.