News

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

1.Reason analyze.
After checking the air slide chute situation, the part with the blocking problem have some raw meal dust accumulated in the air slide chute, that’s mean the air slide fabrics broken or some part air permeability is not stable at least, due to our air slide fabrics well handled in factory and always with the equal air permeability, so we think must have some part broken.
And when the air slide fabric 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 accumulated at the upper side, then cause the blocking problem.
When the raw meal mill operated normally after some time, the feeding part brings stable raw meal volume enter to the air slide chute, this pressed air wall will not effect much due to the resistance will much higher at the feeding part, then the air slide chute return to normal generally.
When checking, due to the broken part always accumulated with the dust, so it is not easy to find the position if the air slide fabrics 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 the area size around 5X20mm, which should be 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 an 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, the air slide fabrics will convex and touch with the dust filter media tightly, so the pressed air wall disappeared, then problem solved.

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

Edited by ZONEL FILTECH