For the back-flushing bag-type ultrafine vertical mill, after the bag room is cleaned, the pressure loss can only be reduced to 20-80% of that before cleaning because there is still a layer of adhering dust. when the cleaning is not complete, the adhesion layer is speckled. if the work is continued, the pressure loss will rise sharply. this shows that the pressure loss of the filter bag has decreased, which does not mean that the dust is completely cleaned.

For multi-chamber bag-type ultrafine vertical mills, the method of off-line cleaning by separate chambers is often used. at this time, although the actual total filtration area of ​​the ultrafine vertical mill is reduced, the pressure loss will increase slightly. when the cleaning is finished and the work is resumed, because the impedance of the bag chamber for cleaning has dropped and the air volume passing through it has increased, the total air volume of the reverse-blow bag ultrafine vertical mill will increase after cleaning, compared with before cleaning, and the pressure loss will increase. will drop.

The dust-removing effect of the back-flushing bag-type ultrafine vertical mill is relatively weak, so the filter cloth is generally recommended to use a lighter woven cloth [300-450g/㎡], which is rich in softness and has a small size change.