The performance of the seal is one of the important indicators of the operational reliability of the fan. This is especially true where高压球迷提供有毒、有害flammable, explosive or precious gases. If the seal is not good, not only will a large amount of precious gas be lost, but more seriously it will cause serious environmental pollution.
1. Labyrinth seal
Labyrinth seals are also called labeling seals and comb-tooth seals. They are the most widely used in fan products. The interstage seals on fan products basically use labyrinth seals. The shaft end seals of the air conveyor are not high in pressure. Labyrinth seals are also used in the case.
2. Floating ring seal
Floating ring sealing is to use the pressure oil film formed between the main shaft of the high-pressure fan and the floating ring to balance the combined pressure of the oil film and the external load (pressure of the working medium) to seal the axial leakage of the working medium. Because the floating ring seal has the advantage of automatic centering, the sealing gap can be smaller, and the amount of leakage can be reduced. The pressure of the sealing body can be adjusted according to the pressure of the sealed medium. The liquid friction between the floating ring and the shaft is maintained. State, thereby avoiding mechanical wear.
This seal is used when the pressure is high or when corrosive gas is transported, to ensure that the transported gas does not leak outward.
3. Mechanical seal
The mechanical end seal is a sealing device that achieves the axial rotation of the seal by the preloading of the elastic element on the static and moving ring end face friction pair and the compression of the medium pressure and the elastic element pressure. Mechanical seals generally use sealing fluid (turbine oil) with a pressure 2.5 to 3.5 higher than the sealed medium to seal the sealed medium. During the rotation, an oil film is established on the friction surface. The pressure of the oil film is from outside to inside, from large to small, and finally reaches the balance with the sealed medium. Since the pressure of the sealing liquid is always greater than that of the sealed medium, the sealed medium generally does not leak, and the sealing liquid leaks inwards. The leaked sealing liquid will be recycled through the oil return hole. Due to structural changes, the amount of oil in mechanical seals is greatly reduced compared to the amount of oil used in floating ring seals, but they are all oil film seals.
4. Dry gas seal
The dry gas seal is a gas film seal, which is the most advanced and best sealing effect of the current turbo compressor. It uses nitrogen or other harmless gas as the sealing medium. It requires high cleanliness of the sealing gas, and has a more complicated gas supply system.