What Is a Spatial Filter?
Filter (filter) is an indispensable device on the conveying medium pipeline. It is usually installed at the inlet of other equipment such as pressure reducing valve, pressure relief valve, water level valve, square filter. The filter is composed of a cylinder, a stainless steel filter screen, a drainage part, a transmission device and an electric control part. After the water to be treated passes the filter cartridge of the filter, its impurities are blocked. When cleaning is needed, as long as the detachable filter cartridge is taken out and re-installed after processing, it is extremely convenient to use and maintain.
- Filtration technology has been used in ancient China for production, and paper made from plant fibers was available in 200 BC. 105 AD
- When the filter is working, the water to be filtered enters through the nozzle and flows through the filter.
- When the solid particles in the suspension are large and the particle size is uniform, the pores of the filtered residue layer are relatively smooth, and the filtrate passes through the residue layer at a higher speed. The use of coagulants to aggregate fine particles into larger agglomerates is beneficial to improve the filtration speed.
- For suspensions with a fast sedimentation rate of solid particles, a filter added to the upper part of the filter medium is used to make the filtration direction consistent with the direction of gravity. The coarse particles settle first, which can reduce the blockage of the filter medium and the filter residue layer. (Such as colloid) mixed with coarse solid particles such as diatomite, expanded perlite, etc., can make the filter residue layer loose; when the viscosity of the filtrate is large, the suspension can be heated to reduce the viscosity. These measures can speed up filtering.
- 1. Efficient and precise filtration: The filter disc filtration technology with special structure has accurate and sensitive performance, ensuring that only particles smaller than the required size can enter the system. It is the most effective filtration system; specifications are 5, 10, 20, 55, 100, 130, 200, etc., users can choose different precision filter disks according to water requirements. The system flow can be flexibly adjusted as required.
- 2. Standard modularization, saving space: The system is based on a standard disc filter unit, which is designed according to modularity, users can choose according to their needs, flexible and variable, and highly interchangeable. The system is compact and occupies a very small area. It can be installed flexibly using corner space. For example, the equipment that handles about 300m3 / h occupies only about 6m2 (general water quality, filtration level 100).
- 3. Fully automatic operation, continuous water discharge: The backwashing process alternates between the units in the filter combination, and the working and backwashing states are automatically switched to ensure continuous water discharge; the water consumption of backwashing is very small, only It accounts for 0.5% of the water output; if air-assisted backwashing is used, the self-consumption water can be reduced to less than 0.2%. High-speed and thorough backwashing can be completed in tens of seconds
- 4. Long life: new plastic filter element is sturdy, no wear, no corrosion, and little fouling. After years of industrial practical verification, there is no wear in 6 to 10 years, it will not age, and the filtering and backwashing effects will not be affected by use. With time.
- 5. High quality and low maintenance: The products meet the corresponding quality standards. All products are tested and tested under simulated operating conditions before leaving the factory. No special tools are required, and few parts are used. Needs routine maintenance. [1]
- It is used on the filter performance test bench. This test bench must strictly purify the system before the test. Therefore, the test system and the pollution injection system serving the test system must be equipped with filters. The filters and the tested Filters are two different things. Their accuracy requirements and dirt capacity requirements are higher than the tested filters. To distinguish between two types of filters in the same test system, this type of filter is called a test bench filter. The test filter is called the test filter.
- Traditional filters usually use a filter screen to separate particulates from the liquid. The filter screen needs to be replaced and cleaned frequently, otherwise it is easy to become clogged. In contrast, fish have a stronger oral filtration capacity. Filter-feeding fish, such as goldfish, spoon-necked bream, basking shark, and whale shark, can retain food particles while filtering, while avoiding clogging of oral filters by debris.
- The research team of William and Mary College in the United States reported on March 29, 2016 that they designed an efficient filter model based on the filtering mechanism of the mouth structure of filter-feeding fish, which can effectively avoid clogging problems. The Nature Online newsletter reported that they designed a 3D printed model of a cone-shaped nylon plastic filter based on a structure known as the "gill arch" in the mouths of the spoon-necked salamanders and bream sharks. They put the model into a water flow pool to observe the filtering effect, and compared it with the filtering mechanism of the oral cavity structure of the spoon-necked salamander.
- It was found that both the model and the mouth of the fish capture particles and prevent clogging by creating vortices in the liquid. The gill arch is a conical structure formed by the bending of hard bones or cartilage to support the gills. The bones in the gill arch are arranged parallel to the old radiator.
- The researchers explained that the tapered structure helps water flow in the fish's mouth, forming water currents and vortices, while the bones arranged in parallel help the small particles gather. The combination of the two forms a "vortex step filtration" mechanism Particles smaller than the gap between the bones can also be intercepted.
- One of the authors of the report, William-Marie College scholar Laurie Sanderson said that this filtering mechanism will be widely used in the future, from micro-filters that filter only cell-sized particles to filters in large industrial pipelines. Play a role. [3]
- Divided into three types: flange connection, thread connection and welding.
- 1. Import and export path :
- In principle, the inlet and outlet diameter of the filter should not be smaller than the inlet diameter of the matching pump, which is generally the same as the inlet pipeline diameter.
- 2. Nominal pressure :
- Determine the pressure rating of the filter according to the highest possible pressure in the filter line.
- 3, holes
- In general low-pressure devices with a pressure below 140kg / cm2, it is common to install only a suction filter, but a return filter and an air filter should also be installed.
- In ordinary medium and high pressure liquid devices with a pressure of 140kg / cm2 or more, the reflux concentration is usually controlled by a reflux filter. However, when there are special requirements for reliability, a high-pressure pipeline filter should be used together.
- (3) To increase its reliability, an electromagnetic proportional control valve or a small flow adjustment valve should be equipped with a terminal filter.
- When using the servo valve, efforts should be made to reduce the pollution concentration of the system. Therefore, high pressure and reflux filters should be used together; in large capacity, a circulation filter should be set, and a terminal filter should be installed on the auxiliary pipeline.
- The installation position of the oil filter in the hydraulic system is usually as follows:
- To be installed at the suction port of the pump:
- Surface oil filters are generally installed on the pump's suction path to protect large hydraulic particles by filtering out large foreign particles. In addition, the filtering capacity of the oil filter should be more than twice the flow rate of the pump and the pressure loss should be less than 0.02 MPa.
- Installed on the oil outlet of the pump:
- The purpose of installing the oil filter here is to filter out contaminants that may invade components such as valves. Its filtering accuracy should be 10 ~ 15m, and it can withstand the working pressure and impact pressure on the oil circuit, and the pressure drop should be less than 0.35MPa. Should also be installed
- When selecting an oil filter, consider the following:
- Filtration accuracy should meet predetermined requirements.
- Can maintain sufficient flow capacity for a long time.
- (3) The filter element has sufficient strength and is not damaged by the action of hydraulic pressure.
- The filter element has good anti-corrosion performance and can work permanently under the specified temperature.
- Easy to clean or replace the filter element.
- Therefore, the oil filter should be selected according to the technical requirements of the hydraulic system, according to the filtering accuracy, flow capacity, working pressure, oil viscosity, working temperature and other conditions.
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- The test principle of the bubble point method: When the filter membrane and the filter element are completely wetted with a certain solution, and then pressurized on one side through the air source (our instrument has an air intake control system, which can stabilize the pressure and adjust the air intake) When the pressure increases, the gas is released from one side of the filter membrane, and bubbles of different sizes and numbers appear on one side of the membrane. The corresponding pressure value is judged by the instrument as the bubble point.
- Diffusion flow test principle: The diffusion flow test means that when the gas pressure is 80% of the bubble point of the filter element, a large number of gas perforations have not yet passed, but a small amount of gas is first dissolved into the liquid phase diaphragm. And then diffuse from this liquid phase into the gas phase on the other side, this part of gas is called diffusion flow.
- Why the diffusion flow method is better: The bubble point value is only a qualitative value. It is a relatively long process from the beginning of the bubble to the last group of bubbles, and cannot be accurately quantified. The measurement of the diffusion flow value is a quantitative value, which can not only accurately determine the integrity of the filter, but also reflect the membrane porosity, flow rate and effective filtration area. This is why foreign manufacturers use diffusion Reasons for stream test integrity.
- Water intrusion test principle: The water intrusion method is dedicated to the test of hydrophobic filter elements. The hydrophobic membrane resists water. The smaller the pore size, the greater the pressure required to squeeze water into the hydrophobic membrane. So under a certain pressure, measure the water flow squeezed into the filter membrane to determine the pore size of the filter element.
- CJ / T 3068-1997 polymer sintered microporous tube filter
- GB / T 13554-2008 high efficiency air filter
- GB / T 14295-2008 air filter
- GB / T 14382-2008 Three-pass filter for pipeline
- GB / T 17486-2006
- , coarse filter
- 1. The core of the filter is the filter core,
- Irrigation of garden lawns and agriculture.
- The filter screen is mainly stainless steel wire mesh.
- Stainless steel wire mesh
- Material: SUS201, 202, 302, 304, 316, 304L, 316L, 321 stainless steel wire
- Weaving: plain weave, twill weave, dense weave
- The specifications of stainless steel wire mesh are 1 mesh-635 mesh. In the case of dense weave, it can reach up to 2800 mesh.
- 304 stainless steel mesh generally refers to "18-8" (18% chromium, 8% nickel). Most of them are basic stainless steel alloys, which are very suitable for mesh fabrics. It can be exposed outdoors and will not rust or oxidize when the outside temperature rises to 1400 degrees Fahrenheit.
- 304L stainless steel mesh is very similar to T-304, except that the carbon content is reduced, which is more conducive to weaving and re-welding.
- 316 stainless steel mesh can be stabilized by adding 2% molybdenum. T-316 is an "18-8" alloy. It is less susceptible to corrosion than other chromium-nickel stainless steels in brine, sulphur water or brine. For example, chloride is an obvious example. The most valuable feature of T-316 is that it has stronger resistance to creep at elevated temperatures. Other mechanical and structural characteristics are the same as T-304.
- 316L stainless steel mesh is very similar to T-316, except that the carbon content is reduced, which is more conducive to weaving and re-welding.
- Uses: Because stainless steel has acid resistance, alkali resistance, abrasion resistance, temperature resistance and other properties, it is often used for sieving (sieve screen) and filtration (filter screen) under acid and alkali environment conditions. It is used as a slurry screen in the petroleum industry and as a screen in the chemical fiber industry Strainer, electroplating industry as pickling screen
- As the name implies, precision filter element is the heart of the filter, and the filter element is generally mainly used in oil filtration, water filtration, air filtration and other filtration industries.
- 1. Breathability of precision filter element: The filter element adopts American strong hydrophobic and oleophobic fiber filter material, and at the same time, it adopts a framework with good permeability and high strength to reduce the resistance caused by the crossing.
- 2. High efficiency of precision filter element: The filter element adopts Germany's fine-pored sponge, which can effectively prevent the oil and water from being carried away by high-speed air flow, so that the small oil droplets passing through the filter can be collected at the lower end of the filter element sponge and discharged to the bottom of the filter container.
- 3. Air tightness of precision filter element: A reliable sealing ring is adopted at the junction of the filter element and the filter case to ensure that the air flow is not short-circuited and to prevent impurities from directly entering the downstream without passing through the filter element.
- 4, precision filter element corrosion resistance: the filter element uses anti-corrosion reinforced nylon end cap and anti-corrosion filter element skeleton, which can be used in harsh working conditions.