The structure of the filter press consists of three parts:
Filter press frame
The frame is the basic part of the filter press. The two ends are the thrust plate and the compression head. The beams on both sides connect the two together. The beams are used to support the filter plate, the filter frame and the compression plate. In order to meet high-level hygiene requirements, the rack needs to be covered with stainless steel. The stainless steel-clad technology can be used as a reference, and its quality can meet the needs of European customers.
A. Thrust plate: It is connected with the support to place one end of the filter press on the foundation. The thrust plate of the chamber filter press has a feed hole in the middle. There are four holes in the four corners, and the upper two corners The hole is the inlet for washing liquid or squeezed gas, and the lower two corners are the outlets (underflow structure or filtrate outlet)
b. Pressure plate: used to compress the filter frame of the filter plate, and the rollers on both sides are used to support the pressure plate to roll on the rail of the beam.
C. Girder: It is a load-bearing component. According to the anti-corrosion requirements of the use environment, hard polyvinyl chloride, polypropylene, stainless steel coating or new anti-corrosion coatings can be selected.
Filter press pressing mechanism
Manual compression, mechanical compression, hydraulic compression.
A. Manual compression: A screw-type mechanical jack is used to push the compression plate to compress the filter plate.
B. Mechanical compression: the compression mechanism consists of a motor (equipped with advanced overload protector) reducer, gear pair, screw rod and fixed
Nut composition. When pressing, the motor rotates forward, driving the reducer and gear pair, so that the screw rod rotates in the fixed nut, and pushing the pressing plate to press the filter plate and the filter frame. When the pressing force becomes larger and larger, the motor load current increases. When it reaches the current value set by the protector, a large pressing force is reached. The motor cuts off the power supply and stops rotating. Because the screw and fixed nut are reliable The self-locking spiral angle can reliably ensure the pressing state during the working process. When retracting, the motor reverses, and when the pressing block on the pressing plate touches the stroke switch, it retracts and stops.
C. Hydraulic compression: The composition of the hydraulic compression mechanism consists of a hydraulic station, a cylinder, a piston, a piston rod, and a Hafran card hydraulic station connected to the piston rod and the compression plate. The structure consists of: motor, oil pump, overflow valve ( Adjusting pressure) reversing valve, pressure gauge, oil circuit, oil tank. When the hydraulic pressing machine is pressing, the hydraulic station supplies high-pressure oil, and the component cavity formed by the cylinder and the piston is filled with oil. When the pressure is greater than the friction resistance of the pressing plate, the pressing plate slowly compresses the filter plate. When the tightening force reaches the pressure value set by the overflow valve (displayed by the pointer of the pressure gauge), the filter plate, filter frame (plate and frame type) or filter plate (chamber type) are compressed, and the overflow valve starts to unload. , Cut off the power of the motor and the pressing action is completed. When retreating, the reversing valve changes direction and the pressure oil enters the rod cavity of the cylinder. When the oil pressure overcomes the friction resistance of the pressure plate, the pressure plate begins to retreat. When the hydraulic compression is automatic pressure maintaining, the compression force is controlled by the electric contact pressure gauge. Set the upper limit pointer and the lower limit pointer of the pressure gauge to the value required by the process. When the compression force reaches the upper limit of the pressure gauge, the power supply When the oil pump is cut off, the power supply is stopped. The compression force is reduced due to internal leakage and external leakage that may occur in the oil circuit system. When it drops to the lower limit pointer of the pressure gauge, the power is turned on and the oil pump starts to supply oil. When the pressure reaches the upper limit, the power is cut off. The oil pump stops supplying oil, so that it circulates to achieve the effect of ensuring the pressing force in the process of filtering the material.
Filter press filter mechanism
The filter mechanism is composed of a filter plate, a filter frame, a filter cloth, and a press diaphragm. Both sides of the filter plate are covered by filter cloth. When a press diaphragm is required, a set of filter plates is composed of a diaphragm plate and a side plate. Both sides of the base plate of the diaphragm plate are covered with rubber diaphragms, and the outside of the diaphragm is covered with filter cloth. The side plates are ordinary filter plates. The material enters the filter chambers from the time material holes on the thrust plate, the solid particles are trapped in the filter chambers due to their particle size is larger than the pore size of the filter medium (filter cloth), and the filtrate flows out from the outlet holes under the filter plate. When the filter cake needs to be squeezed dry, in addition to squeezing with a diaphragm, compressed air or steam can also be used to pass in from the washing port, and the airflow can flush the water in the filter cake to reduce the moisture content of the filter cake.
(1) Filtering method
The way the filtrate flows out is divided into open flow filtration and undercurrent filtration.
A. Open flow filtration: A water nozzle is installed on the outlet hole under each filter plate, and the filtrate flows out from the water nozzle intuitively.
B. Undercurrent filtration: Under each filter plate is provided a liquid outlet channel hole, and the liquid outlet holes of several filter plates are connected to form a liquid outlet channel, which is discharged from the pipe connected with the liquid outlet hole under the thrust plate.
(2) Washing method
When the filter cake needs to be washed, there are open flow one-way washing and two-way washing, undercurrent one-way washing and two-way washing.
A. Open flow one-way washing means that the lotion enters sequentially from the lotion inlet hole of the thrust plate, passes through the filter cloth and then the filter cake, and flows out from the non-porous filter plate. At this time, the outlet nozzle of the orifice plate is closed. Status, the outlet nozzle of the non-perforated plate is open.
B. Open-flow two-way washing means that the washing liquid enters the holes from the two sides above the thrust plate and is washed twice in succession, that is, the washing liquid is washed from one side and then from the other side. The outlet of the washing liquid is the same as the inlet. The direction of the corner line, so it is also called two-way cross washing.
C. Undercurrent one-way washing means that the lotion enters the perforated plate from the lotion inlet hole of the thrust plate in turn, passes through the filter cloth and then through the filter cake, and flows out from the non-porous filter plate.
D. Undercurrent two-way washing means that the lotion enters the two holes on the upper side of the stop plate twice in succession, that is, the washing is firstly washed from one side, and then from the other side. The outlet of the lotion is diagonal Direction, so it is also called undercurrent two-way cross washing.
(3) Filter cloth: Filter cloth is a main filter medium. The selection and use of filter cloth has a decisive effect on the filtering effect. When choosing the filter cloth, the appropriate filter cloth should be selected according to the pH value of the filter material, solid particle size and other factors. The material and pore size are used to ensure low filtration cost and high filtration efficiency. When using, ensure that the filter cloth is flat and not compromised, and the pore size is unobstructed.