The plate frame type filter press is a very mature dehydrating equipment, which is used in the sludge dewatering project in Europe and America. Filter press with filtrate channel filter plate and filter frame parallel arranged alternately, each group of filter plate and filter frame filter cloth between the two, with the pressure side filter plate and filter casing pressure, between the filter plate and filter plate form a filter chamber. Sludge from the inlet flow, water through the filter plate from the filtrate outlet, mud cake accumulation within the box on the filter cloth, filter plate and filter box after peeling off mud cake is easy, with simple operation, filter cake high solid content, high applicability, etc.
The plate frame type pressure filter can be applied to the compressibility of the filter slag or the uncompressed suspension. The concentration of solid particles suitable for suspension is generally less than 10%, and the operating pressure is generally 0.3 ~ 1.6 mpa, with special amount of 3 mpa or higher. The filter area can be increased and decreased with the number of plate frames used. Plate and frame are usually square, filter box side length is 200 ~ 2000 mm, inside box is 16 ~ 80 mm thick, filter area is 1 ~ 1200 ㎡. The plate and frame are pressed by manual screw, electric screw and hydraulic pressure. Boards and frames are made of wood, cast iron, cast steel, stainless steel, polypropylene and rubber.
Plate and frame filter press equipment weight and volume is big, use and the type of sludge dewatering machine adopts the intermittent operation mode, when 50 kg/h solid production, productivity is relatively small, but high dehydration rate, mud cake moisture content can be up to 70% 85%, in addition, the equipment and personnel guards, automaticity is poorer; More active parts, unstable; Lower investment in equipment; Difficult maintenance; The operation is more complex and must be managed by a special person; Short service life.
The plate frame type pressure filter is composed of fixed plate, filter box, filter plate, pressure plate and compression device, and the appearance is similar to the external pressure filter. The manufacturing panels and boxes are made of metal, wood, engineering plastics and rubber, and various forms of filter plate surface slots are used as drainage channels, and the filter boxes are hollow. Pieces of filter plate, filter box arranged alternately, sandwiched between plate and frame filter medium, such as filter cloth, filter box and filter plate through the two ears, frame on the levels of the two equal beams, one end is fixed plate, the other end of the compression plate pressure tight through compaction device at work or away. The filter press can be used to add and discharge filtrate through the channel or plate on the corner of the plate and the frame. There are two types of filtrating flow, the filter cake is gathered in the box during filtration process. The working pressure of the normal plate frame filter press is 0.3 ~ 0.5 MPa, and the pressure filter press is 1 ~ 2MPa.
Advantages and disadvantages: the shortage of the plate and frame filter, filter box feeding mouth easy to jam, filter cake is not easy to remove and can not run continuously, small capacity, low working pressure, average square plate material is not pressure, easy to broken plate, filter cloth is used up big, plate and frame is difficult to achieve unattended, often need to manually from the filter cloth.
The advantages of plate - frame filter press are simple structure, easy operation, stable operation and convenient maintenance. Selection of filter area is flexible and occupies less space; It is adaptable to material and suitable for all kinds of small and medium sludge dewatering treatment.