How to Produce Filter PlateGenerally, the main components of the current plastic filter plateare polypropylene (C3H6nCAS), antioxidant, glass fiber, curing agent and other raw materials. After pre-treatment, breaking and mixing, the various components are evenly distributed. Let the polypropylene raw material be heated and melted. At 260°C~280°C, the polypropylene is stirred, heated and expanded to form a polypropylene viscous liquid. After 20~30 minutes of heating, the polypropylene viscous liquid will be It's time for the next styling.The shape of the filter plate is the abrasive tool used, so before manufacturing the filter plate of the filter press, it is necessary to make the required filter plate mold of the filter press. Different sizes, thicknesses, and styles will have different casting molds. The polypropylene liquid is introduced into the mold, and the upper mold is pressed by a hydraulic press of several tens of MPa, so that there is no air hole in the middle of the manufactured filter plate, which increases the compactness of the filter plate. Then fix the upper and lower molds, remove the hydraulic press, store it at room temperature, wait for it to cool down, and fix the form.The filter plate of such a filter press is basically completed. After the filter plate is cooled, a little processing will be done. Such as making water holes, upper handles, deburring, watering, etc. This is such that the filter plate can be placed on the beam of the filter press, and the filter cloth can be used.

There is a press water inlet hole on the diaphragm filter plate, and a water inlet pipe is installed on the right side of the diaphragm filter press. The water inlet joint is welded on the water inlet pipe. The squeezing pump sends water to the water inlet pipe on the right side of the diaphragm filter press. There are holes in the middle of the diaphragm filter plate. After the water enters, the diaphragm plate expands up and down, and squeezes the mud cake on the chamber filter plate to achieve secondary pressing.There is a liquid outlet hole under the diaphragm filter plate, which is connected with the round holes on both sides of the filter plate to solve the problem of filtrate discharge.The high pressure diaphragm filter press is used in sludge, sewage treatment, and the moisture content of the filter cake is lower than 30%. Compared with the traditional box filter press, the solid content of the filter cake can be increased by more than 2 times. The filter cake can be directly burned in the power plant, turning the sludge into a resource.

Why Filter Plate Not SealingSince the filter chamber of the chamber filter press is formed by extruding and splicing filter plates one by one, and it is necessary to maintain a high-pressure working environment during filtration, naturally, whether it is solid or liquid inside, under the action of pressure, it has high efficiency. Internal energy, if the gap between the chamber filter plate and the chamber filter plate is a little weak or there is a little gap, it will cause the liquid with powerful internal ability to be ejected. The filter plate scours out a one-to-one jet path. With the accumulation of time, this jet path will become larger and larger, and there will be many gaps between the filter plate and the filter plate. The more gaps, the liquid is sprayed out. The more places there are, such a vicious circle will accelerate the damage of the recessed filter plate of the filter press, and finally lead to the fact that the filter plate of the filter press can no longer meet the basic conditions for the sealing of the filter press.

How Filter Plate Broken1. When the sludge is too thick or leaves dry lumps, the feeding port will be blocked. At this time, there is no medium between the recessed filter plates, and only the pressure of the hydraulic system itself remains. At this point, the board itself is easily damaged due to prolonged stress. 2. When the feed is insufficient or the feed contains inappropriate solid particles, it will also cause the board and the frame itself to be overstressed and thus damaged. 3. If the outlet is blocked by solids, or the inlet valve or outlet valve is closed at startup, there will be no pressure leakage, resulting in damage. 4. When the chamber filter plate is not cleaned, sometimes the medium will leak. In the event of a leak, the edges of the board racks will be flushed into small trenches one by one. A large amount of medium leakage will result in no pressure rise and no mud cake formation.

Which kind of filter cloth is better?During the filtration process, the solid particles (fine particles) of the amorphousbb of the filter press and reduces the leakage of porous water between the filter plates of the filter press. The surface high temperature curing technology has a good effect on solving the practical problems of the filter press. Only the monofilament filter cloth can maintain a stable structure without deformation, but the impact resistance and compressive strength of the monofilament filter cloth are not higher than that of the multifilament filter cloth, which is easy to be damaged. At present, there are many typesv filter cloths on the market. According to different materials, there are many chemical fibers; in terms of structure, they are mainly textile and chemical fiber felt, cardboard and filter paper.The filter cloth used in the diaphragm filter press is "high temperature setting (calendering) filter cloth". After the high temperature setting (calendering) filter cloth, the shape of the pores between the cotton yarns changes from a positive bell mouth shape to a reverse bell mouth shape.Therefore, filter cloth manufacturers have produced monofilament and multifilament filter cloths to overcome the shortcomings of monofilament filter cloths. The monofilament filter cloth is used as the sealing layer, and the multifilament filter cloth is used as the support point layer. 

Why Filtered Cakes UnevenThere are two main reasons for the uneven mud cake pressed by the Chamber filter press.One is that the feed channel is blocked, that is, the feed hole in the center of the recessed filter plate is blocked by mud.Therefore, we must first check whether there is residual mud in the feeding channel, and rinse the channel to ensure smooth feeding.Second, the filter cloth is blocked (this could be judged by fast rising feeding pressure. The solution is that we wash PP filter cloth with a high-pressure water gun to ensure that the pores of the filter cloth are not blocked. Therefore, during the use of the filter press, we should regularly clean the filter cloth and feed holes to avoid such problems.

PAC & PAM Function During Filter Press Working Generally speaking, in order to speed up the filter press process and reduce the water content, some chemicals are added. Commonly used are cationic polyacrylamide and polyaluminum chloride. The right amount of addition can play a role in binding the sludge and speed up the filter press process. According to the different filter presses used, the dosage of chemicals is also different. For example, the belt filter press adds more chemicals, and the plate and frame filter presses add less chemicals. Polyaluminum chloride (PAC for short, usually also called water purifying agent or coagulant) has a high degree of electrical neutralization and bridging effect on colloids and particulates in water, and can strongly remove micro-toxic substances and heavy metal ions, with stable properties. Polyacrylamide (PAM for short, also divided into anion (HPAM) cation (CPAM), non-ionic (NPAM) is a linear polymer, is one of the most widely used water-soluble polymer compounds, polypropylene. Amide and its derivatives can be used as effective flocculants, thickeners, paper strengtheners and liquid drag reducers, etc., and are widely used in water treatment, papermaking, petroleum, coal, mining and metallurgy, geology, textile, construction and other industrial sectors) As for how much to add, add PAC or PAM or both. This requires the pharmaceutical manufacturer to combine with the water sample after the experiment. Proper use of the pharmaceutical will directly affect the filtration efficiency of chamber filter press. 

Plate and Frame Filter Press InformationThe plate and frame filter press can be applied to the suspension with large or almost incompressible filter residue. The solid particle concentration of the suitable suspension is generally below 10%.Hydraulic Plate Filter Press operating pressure is generally 0.3 to 0.6 MPa, and can be up to 3 MPa or higher in special cases. The filter area can be increased or decreased with the number of plates and frames used.The plate frame is usually square, the inner length of the filter frame is 200-2000 mm, the frame thickness is 16-80 mm, and the filter area is 0.5-1200 square meters. The plate filter press are pressed by manual screw, electric screw and hydraulic pressure. Plates and frames are manufactured from materials such as wood, cast iron, cast steel, stainless steel, polypropylene and rubber.

How Sludge Filter Press WorkMatching with a ceramic plunger pump, filter press will be full of sludge. After the sludge filter press dewaters the sludge, separate solid and liquid, mud cakes are formed, and the clean water is filtered out and can be directly recycled to re-production.The mud is filtered by the filter chambers with filter cloth, the solid particles inside are retained and become mud cake and remain in the middle of the filter plate.  And the liquid is filtered out for another process.The filter chamber is formed by pressing all the neatly arranged filter plates by the pressing plate. When the entire dehydration process is completed, the pressing plate needs to be returned, the filter plates are separated one by one, and the solid mud cakes trapped in the middle will fall down one by one. The process of unloading the cake can be operated manually or the auto filter press of an automatic plate pulling function.

Import and Export Status of Filter PressChina "filter press" HS code is "84212910". Judging from the import and export volume, my country's export volume is much greater than the import volume. According to statistics, from January to November 2021, the number of checkpoints for filter presses export in China was 407,100, and the number of imports was 2,353.Judging from the import and export amount, China imports high-end filter presses and exports low-end filter presses. According to statistics, from January to November 2021, the export value of China filter press is 89.3701 million US dollars, and the import value is 22.0909 million US dollars.From this status, our company should increase the filter press improvement investment, increase technology study to meet high-end filter press requirements.

How to Install Filter ClothWhen installing the filter cloth of the automatic filter press, attention should also be paid to the method. If the installation is not in place, not only the filtering effect will be greatly reduced, but also the filter cloth and even the equipment will be damaged.  First, sew the center holes of the two pieces of filter cloth together. One of them is folded in half and then rolled into a cylindrical shape. Pass through the feed port in the middle of the filter plate, and then unroll the filter cloth that has passed through. The filter cloths on the other side of the same filter plate are tied together.

Current Filter Press and Undercurrent Filter Press UsageIn general filter presses, open-flow drainage is used, so we are familiar with chamber filter presses or diaphragm filter presses with open-flow drainage. We see such filter presses, when the filtrate passes through the filter chamber Then directly through the drainage pipe under the filter plate, and directly outside the equipment through the faucet. The undercurrent filter press equipment is designed to collect the filtrate under the faucet, and the filtered design is collected through the pipeline. The conventional method is to connect the faucet under the filter plate of the filter press to a sealed hose, and a larger pipe connected to all the hoses is designed under the hose, so that the liquid can be well protected.  Undercurrent filter press is generally suitable for toxic, odorous, volatile and flammable materials.