Study on the problem of handling shaft seal leakage of induced draft fan bearing
Based on the experience of other equipment sealing, the sealing gland was changed to the sealing oil returning plate. The experiment was carried out on the #6 furnace B suction fan seat with a minor repair, which completely solved the oil leakage problem and achieved good expected results. The sealed oil returning disc is processed like a small end cap, and the inner side is processed into a sub-port, so that the linoleum is just embedded therein, and the linoleum is pressed by the oil returning disc to ensure that the original first-class seal continues to exist. At the same time, due to the cavity inside the oil returning disc, an oil chamber is formed, and the oil leaking from the shaft seal linoleum enters the oil chamber, where it is collected centrally, the lower part of the oil returning disc is opened, and the oil draining pipe is installed. When the oil leakage is light, it can be discharged regularly. If the oil leakage is serious, the oil discharge pipe can be connected to the oil drain hole of the bearing housing to flow back to the bearing housing. A second stage seal is formed. The outer side of the oil return plate is made into a dense tooth to form a third-stage seal. Even a small amount of oil droplets will pass through the oil return chamber, and will be sealed here without leaking outward.
For the manufacture of the sealed oil return plate, it is necessary to pay attention to the following points: the position of the fixing hole of the sealing oil return plate should be the same as that of the original pressure cover, so that the oil pan can be fastened by the original screw hole of the bearing end cover without having to drill. Seal the radial gap between the oil return plate and the shaft. The sealing oil returning disc is formed in two halves, and is fastened by bolts and then fixed to the end cap. This is very convenient to disassemble, otherwise it will be troublesome to install inside the bearing housing. The material of the sealed oil returning plate can be selected from lightweight materials such as cast aluminum to prevent the oil pan from being too heavy to fall and rub against the shaft. The size of the seal return oil seat should be fully considered in consideration of the specific distance between the inner end cover and the shoulder of the bearing seat, depending on the actual situation. The linoleum is pressed between the sealing oil returning plate and the end cover of the bearing seat, and a certain gap should be left. After the lining is aged for a period of time, the linoleum can be tightened by tightening the oil pan bolt to strengthen the linoleum. The first level of sealing, the gap should be about 5-8.
After the modification of the #6 furnace B suction fan, after the actual use of the #6 furnace, the sealing effect is very obvious, and the oil leakage can be almost reached. It has the following advantages: easy assembly and disassembly, no need for any fan bearing housing Reconstruction, the workload is small. The sealing oil return tray is easy to manufacture. The cost of the renovation is extremely limited and saves money. The use of low flow rate, that is, the increase of the pipe diameter is uneconomical, because the gravity separation efficiency is not high, the use of two separators, the addition of a pressurized container, increasing the cost of equipment, making the connection on the water tank difficult, can only be used It can be solved on the side of the tank or by lengthening the water tank, but the structure of the separator is simple. The open hole reinforcement type is different from that of the deaerator and the water tank by using large openings and reinforcing plates, which is unfavorable for withstanding frequent alternating stress. And we use small openings, while increasing the wall thickness, there is no such problem.
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