Working principle of plate frame filter press
The plate and frame filter press consists of a set of filter chambers arranged alternately through filter plates and filter frames. The surface of the filter plate has grooves, and the convex part thereof is used for supporting filter cloth. There is a through hole on the side of the filter frame and filter plate. After assembly, it forms a complete passageway, which can pass into suspension, washing water and filtrate. Each side of the board and the frame is supported by a handle on the cross beam, and the pressing device is pressed on the plate and frame.
The filter cloth between the plate and frame plays the role of sealing gasket. The feed pump will suspend the hydraulic pressure into the filter chamber and form a filter residue on the filter cloth until the filter chamber is filled. The filtrate passes through the filter cloth and flows along the filter plate trench to the edge and corner channels of the frame and plate, and then is discharged centrally. After filtration, washing and washing residue can be cleaned.
After washing, sometimes the compressed air is added to remove the remaining washing liquid. Then the filter press is opened and the filter residue is removed, the filter cloth is cleaned, the plate and frame are pressed again, and the next working cycle is started. The plate and frame filter press can be applied to the suspension with high compressibility and near incompressible suspension.
The solid suspension concentration of the suitable suspension is generally less than 10, the operating pressure is generally 0.3 to 0.6 MPa, and the special can reach 3 MPa or higher. The filter area can be increased or reduced with the number of frames used. The frame is usually square, the inner side of the filter frame is 320~2000 millimeters, the frame thickness is 16~80 millimeters, and the filter area is 1~1200 meters 2. 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.
Structure of plate frame filter press
The plate and frame filter press mainly consists of a machine head, a back roof, a middle roof, a pull rod and a plate frame.
(1) according to the way of pressing, it can be divided into three ways: manual, mobile and hydraulic.
A, manual compression: screw the mechanical jack to push the middle roof to compress the filter plate.
B, mechanical compaction: the pressing mechanism consists of motor, worm gear reducer, gear, screw and nut. When compressing, the motor is turning, driving the reducer, rotating the screw rod in the nut, pushing the middle roof to compress the plate and frame. When the motor current reaches a certain value (i.e. the maximum compaction force), turn off the power supply and stop turning. When the motor is returned, the motor can be reversed.
C, hydraulic pressure: Hydraulic compacting mechanism is composed of hydraulic station, oil cylinder, screw rod and locking nut. The components of the hydraulic station are: motor, integrated block, gear pump, overflow valve (regulating pressure), manual reversing valve, pressure gauge, tubing and fuel tank. When the hydraulic pressure is pressed, the manual valve is pushed, so that the hydraulic station can provide high pressure oil through the gear pump, push the piston rod and the screw rod to push out, and push the middle roof to compress the plate and frame. When the pressure reaches the pressure value set by the relief valve (pressure gauge display), the manual valve is reset, and the motor power is switched off, and the pressing action is completed. When returning, the manual valve is pushed in the opposite direction, and the piston rod, the screw rod and the middle roof are started to be recovered.
(2) according to the form of plate and frame, it can be divided into three types: plate frame type, box type and capsule type.