The filter mechanism consists of filter plate, filter frame, filter cloth and press diaphragm. The filter board is covered by filter cloth, and the filter plate is made up of diaphragm plate and side plate when pressing the diaphragm. The substrate of the diaphragm plate is covered with a rubber diaphragm, the diaphragm is covered with a filter cloth, and the side plate is the ordinary filter plate. Material from the thrust plate hole into each filter chamber, solid particles because of its particle size is greater than the pore diameter of filter medium (cloth) trapped in the filter chamber, the filtrate from filter plate at the bottom of the hole of produced liquid flow out. When the filter cake needs to be pressed dry, it can also be used to compress air or steam, which can be used to reduce the moisture content of the cake.
(1) filtering mode
The filtrate outflow is filtered and filtered.
A, light flow filtration: water nozzle is installed on the lower part of each filter plate and the filtrate is directly out of the water nozzle.
B. Dark flow filtration: a liquid channel hole is provided below each filter plate and the outlet of a number of filter plates is connected to an outlet
A pipe that is connected by a fluid hole below the thrust plate is expelled.
(2) washing method
When the filter cake needs to be washed, it has one-way washing and two-way washing, dark flow one-way washing and two-way washing.
Is A unidirectional washing, Ming flow, lotion from lotion into the hole in turn into the thrust plate, wear filter cloth and filter cake, from the hole filter plate, then perforated plate produced liquid water mouth closed, no orifice of produced liquid water nozzle is open.
B, Ming is bi-directional flow washing lotion from both sides of the thrust plate above the lotion into the hole has two times of washing, namely lotion from the side of washing first, then from the other side of the washing, wash the exports and imports are diagonal direction, so also called two-way cross washing.
C, the backflow one-way flow scrubber is the liquid of the lotion from the hydraulic feed hole of the thrust plate into the perforated plate, through the filter cloth and filter cake, from the perforated filter plate.
D, the undercurrent is two-way washing lotion from check two lotion into the hole on either side of the plate at the top of the washing twice, namely washing from the side of washing first, then on the other side of washing, the export of lotion is diagonal direction, so also called undercurrent two-way cross washing.
(3) filter cloth, filter cloth is a kind of main filter medium, the selection of filter cloth and use, has a decisive effect to filtering effect, choose according to the filter material when PH value, such factors as the solid particle size to choose the appropriate filter cloth filter material and aperture to ensure low cost and high filtration efficiency, when using, to ensure that the filter cloth level not discounted, aperture open
1. As a mature dehydration device, filter press is widely used in environmental protection and becomes an important equipment for sewage sludge treatment.
2: the dehydration of the sludge is mainly to remove the capillary water between the sludge particles. The water content of the sludge is often 65% to 80% after the dehydration of the normal machine.
3: mechanical dewatering equipment used to mainly include belt filter press, plate frame filter press and horizontal screw settling centrifuge. Now, it is used to use the vane filter press, vertical hydraulic filter press, diaphragm machine and high pressure plate frame machine.
4. Sludge dewatering can greatly reduce the accumulation of sludge and the cost of transportation during landfill. During composting of sludge, the sludge dehydration can guarantee the smooth composting of compost. (the sludge has lower moisture content during composting process); If sludge incineration, centralized treatment, sludge dehydration rate can greatly reduce the thermal energy consumption, and reduce the cost of hazardous materials.
5: however, the sludge composition is complex, relatively dense and relatively small, and it is usually colloidal, which determines the characteristics of its not easy to dehydrate, so far so far. In addition to the ultra-high pressure vertical hydraulic pressure filter, the rest of the filter press increases drying process to reduce the residual oil (liquid) rate.
6: low power consumption of belt type pressure filter. The water rate of filter cake is low in plastic sheet box, but the centrifugal coning centrifuge is adaptable to the fluctuation of sludge flow, good airtight performance, large amount of treatment and small area. In the past, most sewage treatment plants in China adopt centrifuge, belt filter press and plate frame filter press. The commonly used vane filter press, diaphragm filter press, and ultra-high pressure vertical hydraulic filter press, its technology is unique, is the sludge dehydration ideal equipment.