Vacuum filter is the most widely used filtration machinery at present. It is widely used in industrial production such as chemical industry, environmental protection, food and so on. The vacuum filter can be divided into many kinds according to the different technology and working mode, and each type of filter has its unique working procedure.
External filter drum vacuum filter: continuous and automatic operation, the belt type vacuum filter function effectively filtration, washing, dehydration, operation site clean, easy to check and repair. The disadvantage is that the cost is high, the steam pressure of the hot liquid or the volatile liquid 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 below 10%. It is mainly used in the chemical industry and food industry.
Vacuum filter with inner filter surface drum: it is suitable for the suspension of coarse and thin solid particles. It does not need agitator, and the machine cost is low. It can adapt to the change of feed concentration. If it is needed to operate at high temperature, it is easy to take insulation measures. The disadvantage is that the drum surface can not be fully used, the filter cake needs certain viscosity, otherwise it is easy to fall off, resulting in the decrease of the vacuum degree, the change of the flow rate of feed, and the difficulty of replacing the filter cloth.
Disc vacuum filter: according to the unit filter surface, the price is the lowest and the occupied area is small, but the humidity of filter cake is higher than that of rotary drum vacuum filter. Because the filter surface is vertical, the cake thickness is uneven, easy to crack and difficult to wash. The thin layer cake is difficult to discharge, and the filter cloth is fast wear and easy to block. It is easy to handle the materials with low settling speed and easy filtration, and is not suitable for dealing with non viscous materials. The application range is the same as that of rotary drum vacuum filters.
Rotary table vacuum filter: the structure is simple, the washing effect is good, the washing liquid and the filtrate are separated. For the fast dehydrated slurry, the single filter has a large amount of treatment. The defects are the large area, the fast wear of the filter cloth and the easy jam.
Hopper vacuum filter: it can filter thick material with strong adaptability. It is suitable for separating slurry with mass fraction of 20%, large density, easy separation and full washing of filter cake. It is commonly used in chemical industry, light industry and other industries.
The belt vacuum filter is divided into three kinds, which are fixed room type, mobile room type and filter band intermittently. The belt type vacuum filter is the horizontal filter surface. The filter has high filter efficiency, good washing effect, the filter cake thickness adjustable, the filter cloth can be washed both sides simultaneously, the operation is flexible and the maintenance cost is low, it can be used in chemical industry and pharmacy. Pharmacy can be applied to chemical industry and pharmacy. In the food industry, the separation performance of the slurry with faster settling speed is better than that of the filter cake when it needs washing.