Mechanical Seal Flushing Plan And Characteristics

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

(1) Internal flushing

1. Positive flushing

1) Features: The sealed medium of the working host is used to introduce the sealing chamber from the outlet end of the pump through the pipeline.

2) Application: used for cleaning fluids. p1 is slightly larger than p. When the temperature is high or there are impurities, coolers, filters, etc. can be installed on the pipeline.

2. Backwash

1) Features: The sealed medium of the working host is introduced into the sealing chamber from the outlet end of the pump, and flows back to the pump inlet through the pipeline after flushing.

2) Application: Used to clean fluids and enter and exit. When the temperature is high or there are impurities, coolers, filters, etc. can be installed on the pipeline.

3. Full rinse

1) Features: The sealed medium of the working host is used to introduce the sealing chamber from the outlet end of the pump through the pipeline, and then flows back to the pump inlet through the pipeline after flushing.

(2) External flushing

Features: Introduce clean fluid from the external system that is compatible with the sealed medium to the seal chamber for flushing.

Application: The external flushing fluid pressure should be 0.05--0.1MPa greater than the sealed medium, which is suitable for situations where the medium is high temperature or has solid particles. The flow rate of the flushing fluid should ensure that heat is taken away, and it must also meet the needs of flushing without causing erosion of the seals. To this end, it is necessary to control the pressure of the sealing chamber and the flow rate of flushing. Generally, the flow rate of cleaning flushing fluid should be less than 5m/s;

The slurry liquid containing particles must be less than 3m/s. In order 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, and 0.1-- for double-end mechanical seals. 0.2MP, the orifice position for the flushing liquid to enter and discharge the sealing cavity should be set near the sealing end face and close to the moving ring side. In order to prevent the graphite ring from being eroded or deformed by temperature difference due to uneven cooling, as well as impurity accumulation and For coking, etc., tangential introduction or multi-point flushing can be used. If necessary, the flushing liquid can be hot water or steam.