Plate filter presses are widely used in paper making industry, because it has two steps will need this device. One is for paper pulp, another process is for paper wastewater treatment. Papermaking sludge mainly consists of two parts: residual sludge from biochemical treatment system, and paper pulp lost in production. Because the fiber content is high, and some might contains deinking sludge, clay and calcium carbonate. Compared with other kinds of sludge, thus papermaking sludge is not easy to dewater.
Firstly, coagulant will be used to adjust waste water in advance, and form flocs which are easy to be dewatered. The types and quantities of flocculants added to sludge will be difference according sludg generated in various stages, and vary according to the actual situations. The most suitable combination can be selected through experimental methods in advance. Then will be dewatered by the plate frame filter press and finally get filter cakes with about 50% moisture.
Then the filter cake will be further processed. Now the popular trend is to recycle the cakes and burn them as an energy. In this way, it not only can recycle the heat, but also reduce the dry stack. And finally, the cake ash after burned will be disposed as raw material of cement or concrete, so that turn wastes into resources.