Is the shaft seal of centrifugal blowers generally designed to operate under negative pressure?
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Recently, some of the centrifugal fans in the factory have been experiencing severe air leakage. After checking on site, it seems that the leakage is quite severe at the shaft seal. For imports and exports, we have considered replacing the connectors. I would like to ask whether this is taken into consideration when designing the shaft seal for centrifugal fans. Could it be that, during installation and use, the influence of the piping causes the negative pressure to fail?
I’m not sure what your fan looks like; if it’s a fan with high airflow and high pressure, replacing the comb-shaped seal strip (the sealing assembly) is usually sufficient to resolve such problems.
The pressure and air volume should be fine. There are over twenty fans in total. There should be two types of seals: one is a stuffing box and the other is an air baffle. Some shaft seals are connected to nitrogen pipes, which blow air into them. Some nitrogen pipes also get clogged, broken, or leaky over time. I’m not sure if there’s also a certain connection. Since the process of replacing the seal is quite lengthy, that’s the current situation. Those that can be improved first should be improved first.
That type with comb-like replacement elements, as well as those sealed with nitrogen, also feature comb-like seals; these must be replaced, otherwise the problem cannot be resolved. The packed type can be replaced locally for a short period of time.