Emergency solution for the air slide fabrics broken problem

According to the client's description from the cement plant they adopted the vertical mill for the raw meal preparation, then conveying through an air slide chute system (630X79500mm), the angle of inclination is 8 degrees, with 2 blows (18.5KW).Recently, many blocking problems happened at the upper side of the air slide system (around 800mm to cyclone), always happens when the mill starts to work, but when the mill operating for some time, the blocking problem disappears.

1.Reason analysis.
After checking the air slide chute situation, the part with the blocking problem has some raw meal dust accumulated in the air slide chute, which means the air slide fabrics are broken or some part's air permeability is not stable at least, due to our air slide fabrics well handled in the factory and always with the equal air permeability, so we think must have some part broken.
When the air slide fabric is broken at any part, the pressed air will pass through this part stronger, which will become a pressed air wall at this part, so the fluidized particles can not pass by and accumulate at the upper side, causing the blocking problem.
When the raw meal mill operates normally after some time, the feeding part brings stable raw meal volume to the air slide chute, this pressed air wall will not affect much due to the resistance being much higher at the feeding part, and then the air slide chute return to normal generally.
When checking, due to the broken part always accumulating with the dust, it is not easy to find the position if the air slide fabrics are not broken obviously, so have to clean the air slide fabric surface carefully first, then have a check.
Finally, we found the broken part with an area size of around 5X20mm, which should have been scratched by some sharp parts when installing.

2.Emergency solution.
Clean the raw meal dust at the air slide chute, stop the blower, then the air slide fabric will concave, open the upper cap and get a perforated plate wound with 3 layers of dust filter media, make it cover on the broken part of the air slide fabric tightly and fix well with seal materials, install the upper cute well with sealing.
After that, open the blower, and the air slide fabrics will be convex and touch with the dust filter media tightly, so the pressed air wall disappears, then the problem is solved.

3.Performance
After the emergency treatment, the block problem didn't happen again, and the air slide chute raw meal dust accumulation problem disappeared, which kept the good performance until the next maintenance, then the new air slide fabrics.

Edited by ZONEL FILTECH