Vibration problems of the radial bearings in catalytic flue gas extractors
Thread Content
Our unit consists of a flue gas extractor, a main fan, and an electric motor. A month ago, water was present in the raw material, resulting in large fluctuations in feed volume; this led to severe fluctuations in the pressure in both the settler and the regenerator. The inlet temperature of the flue gas extractor rose to 720 degrees, remaining above 700 degrees for 8 minutes. The vibration of the smoke extractor’s radial bearing rose rapidly from 23 to 50, and the extractor was accompanied by a loud humming sound. After that, we kept the inlet temperature at 670 degrees. Today, a brief reignition caused the temperature at the smoke extractor’s inlet to rise rapidly to 702 degrees; we immediately took action to bring it back down to 670 degrees. The vibration level dropped from 50 to 22, and the humming sound also disappeared. We analyze that last time a large amount of catalyst was adhered to the wheel, and this sudden increase in temperature caused uneven thermal expansion and contraction, resulting in the catalyst falling off the wheel. I’m not sure if it’s due to this reason or pipe deformation I hope someone with experience can help analyze it!
Fortunately, 50 microns isn’t that high, and it has dropped further, but where is the roaring noise coming from? Was steam injected at the fan inlet to facilitate rapid cooling? Under abnormal conditions, the catalyst concentration is very high, making it easy for it to accumulate on the blades.
No steam injection measures were taken while the temperature was being reduced; the steam control for the wheel was set to manual mode, and the flow rate remained unchanged. The humming sound seemed to come from either the outlet of the smoke extractor or the inlet side of the fan.
Sure it’s Weng Ming from the cigarette machine? I think of such situations. Large fluctuations in pressure can very likely cause surging in the main fan; this noise may be coming from the main fan
That can’t be true; all the parameters of the main fan are normal, with no significant changes. Surge doesn’t last a month either, and once the vibration of the smoke extractor decreases, the humming sound disappears as well.