Rotary valve failure
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Help: For the rotary valve used to transport powder, manual rotation works fine after maintenance, but there is an obvious friction sound when power is applied. Upon opening the wall panels, no signs of friction were found, nor were there any signs of friction along the circumference of the cylinder. The bearings have been replaced recently. What could be the cause?
Have you checked the chain? Is there friction between the skeleton seal and the shaft?
Check for any friction in the axial direction; the axial clearance may be too small after the cover is reinstalled. A lateral thrust will be generated once the motor starts operating, so it’s fine to turn it manually.
The quick-drying paint applied to the axial end face of the rotor, as shown in the image above, clearly shows no signs of friction. The cover was removed to check for any areas of friction; it was put back in place and tried again – no abnormal noises were heard, and the current level was normal as well. It’s strange; where did the strange noises I heard before go?
Check whether the end-face seal of the feeding valve has been scratched; use a feeler gauge to check all dimensions, and also inspect the condition of the chain tensioner
Original poster, it’s fine for you to turn the shaft manually. The frictional noise that occurs during rotation is likely caused by the blades rubbing against the casing. There are no positioning pins or protrusions at both ends of the casing, right? Please first ensure proper alignment – check the gap between the tips of the blades and the casing, as well as the gap between the blades and the casing surfaces. Generally, the quality of such discharge valves isn’t very good; proper alignment is crucial. We’ve also encountered problems like this; there’s no other choice but to grind the affected areas, make marks, and then create positioning pins manually
Original poster, it’s fine for you to turn the shaft manually. The frictional noise that occurs during rotation is likely caused by the blades rubbing against the casing. There are no positioning pins or protrusions at both ends of the casing, right? Please first ensure proper alignment – check the gap between the tips of the blades and the casing, as well as the gap between the blades and the casing surfaces. Generally, the quality of such discharge valves isn’t very good; proper alignment is crucial. We’ve also encountered problems like this; there’s no other choice but to grind the affected areas, make marks, and then create positioning pins manually
It seems you’ve done quite a bit of repairs as well; this is the first time I’ve encountered such a situation. Our equipment is imported; the cover plate at the positioning end shows no signs of wear, while the cover plate at the non-positioning end is worn. There is no friction sound when turning the shaft manually – no buzzing or grinding noises. The cover plate at the non-drive end was removed to check for any signs of wear, and after reinstalling it, the noise disappeared again. After testing for half an hour, no abnormal sounds were detected, and the current level was also normal. Now I’m wondering if the retaining ring wasn’t fully expanded; if the retaining ring pliers are broken, it had to be forced in manually. Thank you.
Check if the chain is too tight.
1. The heating for the jacket of the rotary valve is not turned on. 2. During maintenance, the gaps in the tube sheet and the cylinder were not adjusted properly； 3. The bearing has excessive play ； 4. Poor bearing lubrication ；