Posted on January 7, 2022
Filter presses used in.
The manual filter press is a kind of intermittent pressurized filter equipment for solid-liquid separation of various suspensions, with good separation effect and easy to use. It is widely used in various fields requiring solid-liquid separation, such as petroleum, chemical industry, dyestuff, metallurgy, pharmaceutical, food, paper making and sewage treatment, etc. It is suitable for the small filtration industry, which generally uses low pressure and filtration pressure less than 0.4Mpa.
The filter press is mainly composed of three major parts, namely: the frame part, the filter part and the pressing device. When the filter press is in operation, the hand wheel is rotated and the screw is driven to push the pressing plate through the small tooth fainting and large gears to press the filter plate and filter media (filter cloth) located between the pressing plate and the stopping plate to ensure that the filtered material (slurry) with working pressure is pressurized and filtered in the filter chamber. (1) Frame part: The frame constitutes the foundation of the filter press and is used to support the filtering mechanism and connect other parts. It is mainly composed of the thrust plate, pressure plate, pressure part and main beam. (2) Filtration section: It consists of filter plates arranged in a certain order on the main beam and filter media (filter cloth) sandwiched between the plates, forming a filtration unit (filter chamber). (3) Pressing part: It is the power device of the filter press, the main parts of which are the pinion, large gear and screw. The whole machine has reasonable structure design, stable and reliable performance, simple operation, convenient maintenance and wide application, which is the ideal equipment for suspension separation.
The filter press uses a special filter medium to exert a certain pressure on the object, making the liquid percolate out of a mechanical device, which is a common solid-liquid separation equipment. It was used in chemical production in the early 18th century and is still widely used in the chemical, pharmaceutical, metallurgical, dye, food, brewing, ceramic and environmental protection industries.
The filter plate has stable performance, easy operation, safety and labour saving; the metal press cylinder is processed by seamless steel pipe and molded by plastic steel filter plate, which is resistant to high temperature and pressure and durable.
Function: To extract the solids from the mixed liquid and to achieve the function of solid and liquid separation.
Subjects: Coal Technology (primary subject); Mining Machinery Engineering (secondary subject); Coal Processing Machinery (tertiary subject)
History: The first filter press equipment appeared in the early 18th century and was used for chemical industry production.
Pharmaceutical, chemical, standard parts, pharmaceutical, metallurgy, non-standard screws, dyestuff, food, brewing, ceramics, oil refining, sewage treatment and other environmental protection industries.
The structure of the filter press is made up of three parts.
The frame is the basic part of the filter press, the two ends are the stopping plate and the pressing head, and the beams on both sides are used to support the filter plate, the filter frame and the pressing plate.
1, thrust plate: it is connected with the support to situate one end of the filter press on the foundation, the middle of the thrust plate of the chamber filter press is the inlet hole, and there are four holes at the four corners, the holes at the upper two corners are the washing liquid or pressing gas inlet, and the lower two corners are the outlet (dark flow structure or filtrate outlet).
2、Pressing plate: used to press the filter plate and filter frame, the rollers on both sides are used to support the rolling of the pressing plate on the track of the beam.
3, beam: is a load-bearing member, according to the requirements of the use of environmental corrosion, can choose rigid PVC, polypropylene, stainless steel cladding or new anti-corrosion coating and other coating.
Manual pressing, mechanical pressing, hydraulic pressing.
1、Manual pressing: the screw type mechanical jack is used to push the pressing plate to press the filter plate.
2、Mechanical pressing: The pressing mechanism consists of an electric motor (equipped with advanced overload protector), reducer, gear payment, screw and fixed nut. When pressing, the motor is turning, driving the reducer and gear payment, making the filament rod rotate in the fixed nut, pushing the pressing plate to press the filter plate and filter frame. When the pressing force becomes bigger and bigger, the motor load current increases, when it reaches the current value set by the protector, the maximum pressing force is reached, the motor cuts off the power supply and stops rotating, because the filament rod and the fixed filament mother have a reliable self-locking spiral angle, it can reliably ensure the pressing state during the working process, when it is returned, the motor reverses, when the pressure block on the pressing plate touches the travel switch, it is returned to stop.
3, hydraulic pressing: hydraulic pressing mechanism consists of a hydraulic station, oil cylinder, piston, piston rod and piston rod and pressing plate connected to the Havlan card hydraulic station structure consists of: motor, oil pump, relief valve (to adjust the pressure) reversing valve, pressure gauge, oil circuit, oil tank. When the hydraulic pressing machinery is pressed, the high pressure oil is supplied by the hydraulic station, the component cavity formed by the oil cylinder and piston is filled with oil, when the pressure is greater than the frictional resistance of the pressing plate running, the pressing plate slowly presses the filter plate, when the pressing force reaches the pressure value set by the relief valve (shown by the pointer of the pressure gauge), the filter plate, filter frame (plate and frame type) or filter plate (chamber type) is pressed, the relief valve starts to unload, at this time, the power supply to the motor is cut off and When the pressing action is completed, the reversing valve is reversed and the pressure oil enters the rod cavity of the cylinder, when the oil pressure can overcome the friction resistance of the pressing plate, the pressing plate starts to return. Filter Press When the pressure reaches the upper limit of the pressure gauge, the power supply will be cut off and the oil pump will stop supplying power, as the internal and external leakage of the oil circuit system may cause the pressure to drop, when it reaches the lower limit of the pressure gauge, the power supply will be turned on and the oil pump will start supplying oil, the pressure will reach When the pressure reaches the upper limit, the power supply is cut off and the oil pump stops supplying oil, so that the cycle can achieve the effect of ensuring the pressing force in the process of filtering materials.
The filtering mechanism consists of a filter plate, a filter frame, a filter cloth and a pressing diaphragm. The diaphragm plate is covered with rubber diaphragm on both sides of the substrate, the diaphragm is covered with filter cloth on the outside, and the side plate is the common filter plate. The solid particles are retained in the chamber because their particle size is larger than the pore size of the filter media (filter cloth), while the filtrate flows out from the outlet hole below the filter plate. When the filter cake needs to be pressed dry, in addition to the diaphragm press, compressed air or steam can be used to pass through the washing port, and the airflow washes away the water in the filter cake to reduce the water content of the filter cake.
(1) Filtration method
The way the filtrate flows out is divided into open-flow filtration and dark-flow filtration.
A. Open-flow filtration: Each filter plate is equipped with a water nozzle on the lower outlet hole, and the filtrate flows out intuitively from the water nozzle.
B. Concealed flow filtration: the bottom of each filter plate is equipped with 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 by a pipe connected to the liquid outlet hole below the stopper plate.
(2) Washing method
When the filter cake needs to be washed, there are open flow one-way washing and two-way washing, dark flow one-way washing and two-way washing.
A. One-way washing in open flow is that the washing liquid enters from the washing liquid inlet hole of the stopper plate, passes through the filter cloth and then through the filter cake, and flows out from the non-porous filter plate, at which time the outlet nozzle of the porous plate is closed and the outlet nozzle of the non-porous plate is open.
B. Two-way washing is the washing liquid from the top of the stopper plate on both sides of the washing liquid into the hole has been washed twice, that is, the washing liquid first from one side of the washing liquid and then from the other side of the washing liquid, the outlet of the washing liquid with the import is diagonal direction, so also called two-way cross washing.
C. Concealed one-way flow washing is that the washing liquid enters the perforated plate in turn from the washing liquid inlet hole of the stopper plate, wears the filter cloth and then passes through the filter cake and flows out from the non-perforated filter plate.
D. Dark flow two-way washing is that the washing liquid is washed twice in succession from the two washing liquid inlet holes on both sides above the stop plate, i.e. washing is washed from one side first and then from the other side, and the outlet of the washing liquid is in the diagonal direction, so it is also called dark flow two-way cross washing.
(3) Filter cloth: filter cloth is a major filter media, the choice and use of filter cloth has a decisive role in the filtration effect, the choice should be based on the PH value of the filter material, solid particle size and other factors to choose the appropriate filter cloth material and aperture to ensure low filtration costs and high filtration efficiency, when using, to ensure that the filter cloth is flat and not folded, the aperture is unobstructed.