开始 应用于化工脱水的机械。 Plate and frame filter presses are machines that have been used in chemical dehydration. Although plate and frame filter presses are generally operated intermittently, with large investment in infrastructure equipment and low filtration capacity, but because of their strong filtering force, high solid content of filter cake, clear filtrate, high solid recovery, and conditioning drugs Low consumption and other advantages, is still widely used in some small sewage plants. In recent years, due to policy requirements, treatment of sand field mud and piled waste mud has been required to reduce the area of the drying plant, reduce environmental pollution, achieve energy conservation and emission reduction, and protect deep forest vegetation.
95%~97% 的含水率，体积仍很大。 After the sludge is concentrated and digested, it still has a moisture content of about 95% to 97% , and its volume is still large. Sludge dewatering can further remove the interstitial water and capillary water in the sludge and reduce its volume. 70%~80% ，其体积为原体积的 1/10~1/4 ，有利于后续运输和处理。 After dehydration treatment, the moisture content of the sludge can be reduced to 70% to 80% , and its volume is 1/10 to 1/4 of the original volume , which is conducive to subsequent transportation and treatment. The mechanical dewatering methods of sludge include filter dewatering, centrifugal dewatering, and squeeze dehydration. Filter dewatering includes vacuum filtration and pressure filtration; centrifugal dewatering is performed by a centrifuge; dehydration is performed by a screw press or a roller press. . Common methods are pressure filtration and centrifugal dehydration. The sludge filtration and dehydration is based on the pressure difference between the two sides of the filter medium as the driving force, so that the sludge moisture is forced to pass through the filter medium to form a filtrate, and the solid particles are trapped on the medium to form a filter cake, thereby achieving the purpose of sludge dehydration. 开始 应用于化工脱水的机械。 Plate and frame filter presses are machines that have been used in chemical dehydration. Although plate and frame filter presses are generally operated intermittently, with large investment in infrastructure equipment and low filtration capacity, but because of their strong filtering force, high solid content of filter cake, clear filtrate, high solid recovery, and conditioning drugs The advantages of superior consumption are still widely used in some small sewage plants.
The plate and the frame are arranged alternately, and filter cloth is covered on both sides of the filter plate, and the plate and the frame are compressed with a pressing device, that is, a filter press chamber is formed between the plate and the frame. 0.2~0.4MPa 的污泥，由该通道进入压滤室，滤板的表面刻有沟槽，下端钻有供滤液排出的孔道，滤液在压力下，通过滤布、沿沟槽与孔道排出滤机，使污泥脱水。 There are small holes in the middle of the plate and the upper end of the frame. After compaction, it becomes a channel. The sludge pressurized to 0.2 ~ 0.4MPa enters the filter chamber through this channel. The surface of the filter plate is engraved with grooves and the lower end. A hole is drilled for discharging the filtrate, and the filtrate is discharged through a filter cloth, along the groove and the hole under a pressure filter under pressure to dehydrate the sludge. Automatic plate and frame filter presses have been developed at home and abroad. FeSO4 · 7H2O ）。 Plate and frame filter presses can withstand higher sludge specific resistance than vacuum filters, which can reduce the consumption of conditioning agents and use cheaper chemicals (such as FeSO4 · 7H2O ). 5 × 1011~8 × 1012m/kg 时，可以不经过预先调理而直接进行过滤。 When the specific resistance of the sludge is 5 × 1011 ~ 8 × 1012m / kg , it can be directly filtered without prior conditioning. The mud cake yield and mud cake moisture content of the plate and frame filter press shall be determined based on test data or similar operating experience. 75%~80% 。 The moisture content of mud cake can generally be 75% ~ 80% .
Design requirements of plate and frame filter press
1 ）过滤压力为 0.4~0.6MPa （约为 4~6kg/cm2 ）； ( 1 ) Filtration pressure is 0.4 ~ 0.6MPa (about 4 ~ 6kg / cm2 );
2 ）过滤周期不大于 4h ； ( 2 ) the filtering period is not more than 4h ;
3 ）每台过滤机可设污泥压入泵一台，泵宜选用柱塞式； ( 3 ) Each filter can be equipped with a sludge pressure pump, and the pump should use a plunger type;
4 ）压缩空气量为每 1m3 滤室不小于 2m3/min （按标准工况计）； ( 4 ) The volume of compressed air is not less than 2m3 / min per 1m3 filter room (based on standard operating conditions);
5 ）板框脱水应注意良好的通风、高压冲洗系统、调理前污泥磨碎机设置、压滤后泥饼破碎机设置等。 ( 5 ) Pay attention to good ventilation, high pressure flushing system, sludge grinder settings before conditioning, mud cake crusher settings after pressure filtration, etc.
The design method of filter press dehydration is mainly to calculate the cake yield, the area and number of filter presses required according to the sludge treatment amount, dewatered sludge concentration, filter press working procedures, and filter pressure.
The dewatering area of the plate and frame filter press is calculated as follows:
A —压滤脱水面积， m2 ； Where A is the filter press dehydration area, m2 ;
m3 ； QS — amount of sludge (sludge input) per dehydration, m3 ;
m3/(m2 · h) ； q — dehydration load, m3 / (m2 · h) ;
h 。 t — each dehydration time, h .
A 进行板框压滤机选型。 Select the plate and frame filter press according to the calculated filter press dehydration area A. 2~3 台，并在脱水车间布置全套设备。 Select at least 2 ~ 3 units, and arrange a full set of equipment in the dewatering workshop.