Reasons for the large difference in shaft temperatures before and after the centrifugal blower
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As shown in the figure, this is the DCS screen of the centrifugal blower system for this device. Question: Why is there a significant difference in temperature between the front and rear axes of the blower? The temperature of the rear axis is about 11°C higher than that of the front axis. Thank you!
This post was last edited by 3983596_FPPZ on 2018-10-11 08:45; the load-bearing capacity of the shafts varies
This post was last edited by CHANGBAISHI on 2018-10-11 09:17. It is necessary to check whether the oil pressure at the two lubrication points is equal; factors such as bearing clearance, the dynamic balance of each stage of the impeller, and the level of installation can all affect the bearing temperature. It should be taken apart for inspection.
Check whether the dynamic balance of the impeller is abnormal, and verify whether the impeller bearings are operating properly
A high temperature on the load side is normal; please measure the vibration levels as well to determine whether it’s a bearing issue or a problem with the motor’s balance.
The vibration values for the front and rear axles are similar; in fact, the front axle has a slightly higher value than the rear axle!
Judging from your operation screen, the clearance of the rear bearing appears to be slightly smaller than that of the front bearing, but the temperature values are within normal ranges, so there’s no need to worry
As a supplementary note, pay attention to the errors in gauge temperature readings; overall, the temperatures of the upper and lower bearings are acceptable (generally, bearings should not exceed 88 degrees). Of course, it’s better if the error is within 2 to 3 degrees.
Actually, I think you didn’t mention the most important point upstairs: in a centrifugal blower, the inlet side is at the front bearing end, where the air entering does not get compressed; it is at atmospheric temperature. The inlet side serves a cooling function, whereas the outlet side involves compressed air. Both the casing temperature and the shaft temperature are high, and heat conducts from one place to another, so it’s normal for the rear bearing temperature to be high. You can use a thermometer to measure the temperatures of the inlet and outlet volutes of the blower to verify this.
Looking at the image, the vibration of both the front and rear axles is not high, and the bearing temperatures are also acceptable at the moment; there are no major issues for now.