Method of flushing mechanical seals
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Our factory manufactures pumps for handling media with high viscosity, and these pumps use external seal cooling water. However, this cooling water is discharged directly without being reused. Currently, the pressure of the medium is higher than that of the cooling water, which results in a short service life for the seals. Is this caused by an incorrect choice of seal flushing system?
The cooling water must have pressure, with a valve and pressure gauge at the outlet
The seal cooling water and the medium are part of two separate systems, and they should have no impact on the service life of the seal.
It seems the poster has chosen option 62. What medium, and what is the temperature of the medium? What is the pump inlet pressure? What is the viscosity then?
The medium temperature is around 10 degrees, and its viscosity is relatively high; the flow rate calculated is 0.1 m/s. It isn’t actually a pump – pressure is applied to this device by a pump, at around 5 kilograms, while the pressure of the cooling water is around 4 kilograms.
Check whether the sealing component of the damaged mechanical seal is damaged... and then determine the cause of the damage. The flushing medium and the system medium belong to two separate systems, so there is no necessary connection between them
I don’t understand. If it’s not a pump, what kind of device is it? Is it the seal of the mixer? The pressure inside the sealed cavity is 5 kilograms, while the pressure on the outside is lower; as a result, during operation very little of the medium leaks out. This solution based on model 62 is designed to carry away this small amount of leaked medium, thereby keeping the sealing surface clean. According to API standards, the seal can withstand a pressure difference of up to 40 kilograms; the pressure difference you have is not sufficient to cause damage to the seal. The main reason for seal leakage is a quality issue with the seal itself, and it has nothing to do with the pressure difference between the inside and outside.
It is a grinding pump that is primarily used to grind the medium into finer particles
Does that mean the medium contains particles? That requires better materials for the stationary and rotating rings; for example, both should be made of SiC. Can it enter other media? Plan 32 is the best.
I use closed oil cooling; the oil is cooled by circulating water. The mechanical seal is of the dynamic and static ring type, but it keeps breaking down – several sets need to be replaced in a year