Analysis: The filter in the water treatment industry mainly has quartz sand filter, activated carbon filter, multi-media filter, bag filter and so on.
Quartz stone filter
Quartz sand mechanical filter is the use of quartz sand as a filter medium, under a certain pressure, the high turbidity of water through a certain thickness of granular or non-granular quartz sand filtration, effective interception to remove suspended matter in the water, organic matter, colloid particles, microbial chlorine, odor and some heavy metal ions, so that the water clarification of the water treatment device. According to different water production, need to be equipped with different mesh number (different diameter of quartz sand particles), it and activated carbon composed of activated carbon filter, with sand 枃 into the removal of iron spade filters are collectively referred to as quartz sand filter.
Multimedia filter
Multi-media filter, are used for water treatment turbidity, softened water, and pure water of the pre-stage multi-media filter (filter bed), both the use of more than two media as a filter layer of the media filter, in the industrial circulating water treatment system, to remove impurities in sewage, adsorption oil, so that the water quality in line with the requirements of recycling. The role of filtration is mainly to remove suspended or colloidal impurities in water, especially to effectively remove tiny bacteria that cannot be removed by precipitation technology, BOD5 and COD also have a certain degree of removal effect.
Activated carbon filter
The activated carbon filter uses granular activated carbon to further remove the residual chlorine, organic matter and suspended matter impurities in the effluent of the mechanical filter, providing good conditions for subsequent reverse osmosis treatment.
The activated carbon filter mainly uses activated carbon organic flocculants with high carbon content, large molecular weight and large specific surface area to physically adsorb impurities in water to meet the water quality requirements. When the water flows through the pores of activated carbon, various suspended particles and organic matter are adsorbed in the activated carbon pores under the action of van der Waals force; At the same time, the chlorine (hypochlorous acid) adsorbed on the surface of the activated carbon has a chemical reaction on the surface of the carbon and is reduced to chloride ions, thus effectively removing chlorine and ensuring that the residual chlorine in the effluent is less than 0.1ppm, meeting the operating conditions of the RO membrane. Over time, the retention of activated carbon in the pores and between the particles gradually increases, so that the pressure difference between the front and back of the filter increases until it fails. Under normal circumstances, according to the pressure difference before and after the filter, the filter material is backwashed by the reverse water flow, so that most of the intercepts adsorbed in the activated carbon pores are stripped and taken away by the water flow, and the adsorption function is restored; When the activated carbon reaches the saturated adsorption capacity and completely fails, the activated carbon should be regenerated or replaced to meet the engineering requirements.
The surface area of activated carbon has strong physical adsorption capacity. Activated carbon filter device is to use activated carbon as a filter medium, the use of activated carbon itself has adsorption and decolorization ability, remove impurities in the liquid, so that the liquid is purified. It is often used in the pre-treatment of reverse osmosis equipment and the filtration of groundwater, sewage and other suspended solids. Widely used in food, medicine, electronics, chemical, industrial wastewater and other industries in the water treatment project is the pretreatment equipment in the water treatment process, used to prevent water pollutants on the subsequent equipment pollution, can also be used to improve the smell and color of water. The activated carbon filter mainly uses the adsorption and decolorization ability of activated carbon itself to remove impurities in the liquid and purify the liquid
Precision filter
Precision filters (also known as security filters) are mostly made of stainless steel shell, internal filter elements (such as PP cotton), mainly used in multi-media pre-treatment filtration, reverse osmosis, ultrafiltration and other membrane filtration equipment before. It is used to filter out fine material (e.g. small quartz sand, activated carbon particles, etc.) which has been filtered through a variety of media to ensure the quality of the water and to protect the membrane filter element from large particulate matter. Precision filter device installed in the filter element accuracy level can be divided into 0.5us,1us,5us,10us, etc., according to different occasions to choose different filtration accuracy, to ensure the accuracy of the water and ensure the safety of the post-stage membrane elements. The precision filter device is mainly composed of a filter shell, a filter element, etc., and the filter shell is mostly composed of R304 stainless steel material, such as R316 stainless steel for special occasions such as acid and alkali resistance. The filter element in the middle of the filter shell is mainly PP filter cotton core, and wire wound filter or activated carbon filter can also be used in some occasions. The number of filter elements installed can range from one to dozens, mainly according to the size of the processing capacity to determine. picture
Bag filter
Bag filter is a kind of pressure filter device, mainly composed of filter cartridge, filter cartridge cover and quick-opening mechanism, stainless steel filter bag strengthening net and other main components, filtrate by the filter shell side inlet tube into the filter bag, filter bag itself is installed in the strengthening net basket, liquid penetration through the required fineness of the filter bag can obtain qualified filtrate, impurity particles are intercepted by the filter bag. The machine is very convenient to replace the filter bag, filter basically no material consumption.
Bag filter has many advantages such as reasonable structure, good sealing, strong flow ability and easy operation. In particular, the filter bag side leakage probability is small, can correctly ensure the filtration accuracy, and can quickly change the filter bag, so that the operating cost is reduced. The inner and outer surfaces of the filter are solved by mechanical sandblasting, which is average and easy to clean. We know that the filter method taken by the bag filter is the side-in and side-out method, and the method of side-in and side-out can also be taken, and the filter liquid medium is pressed into or pumped into the bag filter barrel through the pressure in the pipeline, and the liquid medium to be filtered is filtered through the electro-polishing punching to support the filter blue filter bag, and the changed solid liquid arrives at the result of the liquid medium being filtered.
The structural design of the bag filter is made of four sets of swinging hammer ring head bolts to seal the top cover and the filter cartridge tightly, so that the filter can withstand extremely high filtration pressure and water hammer pressure impact. The bag filter is composed of three parts: filter drum, filter basket, filter bag, compact structure and simple; The liquid to be filtered enters through the inlet of the filter, flows into the filter bag, and after being intercepted by the filter bag, flows out from the outlet of the filter. The import and export design of bag filter generally adopts the mode of side entry and bottom out, which is convenient for cleaning.
