Analysis of the purpose and method of flushing application in mechanical seal

The purpose of the rinsing is to prevent the accumulation of impurities, to prevent the formation of the airbag, to maintain and improve the lubrication, etc., and to have a cooling effect when the temperature of the rinsing liquid is low. The main methods of washing are as follows:

First, internal flushing

Flushing

(1) Features: Using the sealed medium of the working host, the outlet end of the pump is introduced into the sealed chamber through the pipeline.

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

2. Backwashing

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

(2) Application: used for cleaning fluid, and p into 3. full flush

(1) Features: The sealed medium of the working host is used, and the outlet end of the pump is introduced into the sealed chamber through the pipeline, and then flushed and then returned to the pump inlet through the pipeline.

(2) Application: The cooling effect is better than the first two, used for cleaning fluid, and p1 is close to p and p.

Second, external flushing

Features: Introduce the external system to the sealed cavity for cleaning with a cleaning fluid compatible with the sealed media.

Application: The external flushing fluid pressure should be 0.05-0.1 MPa larger than the sealed medium. It is suitable for occasions where the medium is high temperature or solid particles. The flow rate of the rinsing liquid should be such as to take away the heat, and also need to meet the needs of rinsing, and will not cause erosion of the seal. To do this, it is necessary to control the pressure of the sealed chamber and the flow rate of the flushing. The flow rate of the general cleaning rinse should be less than 5 m/s; the slurry containing the particles must be less than 3 m/s. To achieve the above flow rate, the rinse and the sealed chamber The difference of pressure should be <0.5MPa, generally 0.05-0.1MPa, and the double-end mechanical seal can take 0.1-0.2MP. The position of the flushing liquid into and out of the sealing cavity should be set near the sealing end face, and should be On the side close to the moving ring, in order to prevent the graphite ring from being eroded or to cause temperature difference deformation due to uneven cooling, and impurity accumulation and coking, etc., tangential introduction or multi-point rinsing may be employed. The rinse solution can be hot water or steam if necessary.