Zonel Filtech focuses on helping our clients improve the dust collector maintenance works, and sometimes get questions from the clients’ about why the dust filter bags always break from the bottom part. Zonel Filtech offers some analysis as follows:
1. If broken from the reinforcement part:
A. If the broken direction is from the inner side to the outer side of the filter bags, that means the bottom of the cage is too small, as usual, the bottom caps of the cage are always smaller than the cage body, but should not exceed 5mm.
B. If the broken direction is from the outer side to the inner side, or just the outside of the reinforcement filter bags are broken and the sewing thread breaks and drops the bottom, then the possibilities are many, but mainly are following 3:
a. The distance of the holes in the bag tube sheet is too small. Normally if the length of the filter bags does not exceed 8 meters, the distance between the edge to edge of the holes in the bag tube sheet at the length direction of the blowing pipe request 40~80mm, The longer the bag, the bigger the hole distance; at the vertical direction of the blowing pipe need to be even bigger.
When purging the filter bags, the filter bag will shake, if the distance is too small, the bottoms of the filter bags very easily touch with each other and break sooner.
From standard, the distance from hole center to hole center is 1.5times of the diameter of the filter bags, while when operating, to save cost and space, the designer always arranges the smaller distance, if so, the short bag is fine, but when the bag is long, this problem easy to happen especially the bag tube sheet or cages have any tolerances.
b. Whether the bag tube sheet is strong enough, i.e. the bag tube sheet shape is not easy to change, because normally flat tolerance does not exceed 2/1000 to the length of the bag tube sheet, or the filter bag bottom is very easy to touch with each other, and easy to broken.
c. Whether the cage is straight enough. The shape changed cage will make the bag bottom touch with other filter bags, so easy to break.

2. If the bottom round sheet is broken, i.e. the bottom itself is broken. The reasons mainly 2:
A. Whether the air inlet from the dust hopper?
If yes, please check whether the air inlet speed is too fast;
whether the dust air crashes to the bottom directly;
whether the particle size is too big (if yes, the cyclone may needed); whether the inlet part installed the air leading set, etc.
B. the bottom very easily breaks when the dust accumulates too much in the hopper, especially when these DCs are designed the manually clean the hopper but hot clean on time always or auto designed but the discharge system breaks, if so the dust in the hopper may touch with the bottom of the filter bags, if the dust is high-temperature particles, which will lead the bottom sheet of the filter bags broken faster; also in this condition, the bottom of the filter bags very easy to crash by vortex, the air and coarse dust crash the bag bottom time to time, then easily broken.