Mechanical seal – how does a sealing tank work?
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How does the sealing fluid circulate? Is there pressure in the sealed tank? Is there a component similar to an impeller inside the mechanical seal that serves to pump, allowing the sealing fluid to circulate on its own and maintain a certain pressure?
Mechanical seals achieve sealing through the contact surface between the rotating and stationary rings, aided by spring force and a water film; as a result, high requirements are placed on the material used, the manufacturing process, and the quality of the cooling water. If the material is not chosen appropriately, if the sealing surface is slightly deformed, or if the cooling water has poor quality (containing impurities, being at high temperature, or experiencing sudden interruptions in supply), the seal will be damaged immediately. Their allowable linear velocity is less than 60 m/s, and they are very sensitive to vibrations and vaporization. In China, the service life of mechanical seals is around 8,000 hours.
A pumping ring is installed on the sealed shaft sleeve. Quite a good impeller.
Understanding the principle of the [thermal siphon reboiler] makes it clear.
What type of flushing is used for machine seals? Seems like I haven’t seen it before
It should be the 53B flushing scheme, with a double-faced mechanical seal that can handle pressure. The pressure inside the tank is required to be about 0.1 Mpa higher than the pressure in the sealing chamber; a pumping ring is installed on the sealing spring seat to provide the driving force for the circulation of the flushing fluid.
I checked, and it seems to be the plan53A rinsing protocol
This is a 52-type solution, which uses the pump efficiency ring on the mechanical seal to convey the medium and cool and lubricate the mechanical seal. I’m not sure what medium you’re using; on our end, the top filling line is connected to the vent line, so there’s basically no pressure in the tank.
Yes, I got it wrong; B is the one with a accumulator
Then why is the sealed tank pressurized? Without the rotation of the pressure pump shaft, it’s not possible to make the pump impeller rotate, thereby achieving cyclic lubrication and cooling. What is the purpose of applying a certain amount of pressure then??? To prevent damage to the dynamic seals and leakage? ? ? ? ?