During the use of the high-pressure centrifugal fan, we all know that the sealing performance is the key to determining the safety of the equipment. If the sealing is not good, it will cause gas leakage, so we must choose the appropriate sealing form.
The main sealing form of high pressure centrifugal fan
1. Labyrinth seal
This kind of sealing method is also known as puller seal and comb seal. It is widely used. The labyrinth seal is basically used for the interstage seal on the fan, and the shaft end seal for conveying air is used. However, this method is only suitable for under low pressure.
2. Floating ring seal
This sealing method uses the pressure oil film formed between the main shaft and the floating ring, and the balance between the combined pressure of the oil film and the external load to seal the axial leakage of the working medium. Because the floating ring seal has the advantage of automatically aligning the center center, the sealing gap can be slightly smaller, and the leakage amount can also be reduced. Friction state, thus avoiding mechanical wear. The floating ring sealing method can be used in the occasions where the pressure is high or the corrosive gas is transported, which can ensure that the gas does not leak.
3. Mechanical seal
This is a sealing device that achieves the axial rotation of the seal by the preloading of the elastic element on the friction pair of the static and dynamic ring end faces and the pressing of the medium pressure and the pressure of the elastic element. This sealing method mainly seals the medium with a sealing liquid whose pressure is higher than that of the sealed medium by 2.5 to 3.5. During rotation, an oil film is established on the friction surface, and the pressure of the oil film is from the outside to the inside, from large to small, and the end balances with the sealed medium. Because the pressure of the sealing liquid is greater than that of the sealed medium, the sealed medium generally does not leak, but there is a small amount of leakage of the sealing liquid inward, and the leaked sealing liquid will be recycled through the oil return hole. According to the change of structure, the oil amount of mechanical seal is greatly reduced than that of floating ring seal, but both belong to oil film seal.
4. Dry gas seal
This sealing method is also called air film sealing, mainly using harmless gas and nitrogen as the sealing medium. The cleanliness of the sealing gas is very high.
After the above introduction, it can be seen that the sealing forms of high-pressure centrifugal fans are mainly divided into labyrinth seals, floating ring seals, mechanical seals, dry gas seals, etc. Different sealing methods are suitable for different occasions and specifications, so they should be selected and used according to the situation.
