The vacuum filter is the most widely used filter machine widely used in chemical, environmental protection, food and other industrial production. The vacuum filter can be divided into many kinds according to the different technology and working way, and each filter has its unique vacuum belt filter's working process. The external filter drum vacuum filter can continuously and automatically operate filtration, washing, dehydration, clean operation field, easy to check and repair. The disadvantage is that the cost is high, the steam pressure of the liquid or the volatile vacuum filter is limited, the boiling point is low or the volatile material can not be filtered at the operating temperature. It is difficult to deal with the slurry with more solid content and larger particle characteristics, and the moisture content of the filter cake is about 30%, and it is rarely lower than 10%. It is mainly used in the chemical and food industry.
The internal filter drum vacuum filter is suitable for filtering solid particles and the suspension of coarse and fine particles. It does not need the low cost of the machine and can adapt to the change of the concentration of feed. It is easy to take thermal insulation measures if it is needed to operate at high temperature. The disadvantage is that the drum surface can not be separated from the full use of the box type filter press, the filter cake needs some viscosity, otherwise it will fall off easily. The vacuum degree decreases and the feed flow rate changes, so it is difficult to replace the filter cloth.