Overview
Filter is an indispensable device on the pipeline to transport media, usually installed in the pressure reducing valves, pressure relief valves, water level valves, or the inlet side of other equipment, used to eliminate impurities in the media to protect the normal use of valves and equipment. When the fluid enters the filter cartridge with certain specifications, the impurities are blocked, and the clean filtrate is discharged from the filter outlet, when the need for cleaning, as long as the removable filter cartridge can be taken out and reloaded after processing, therefore, the use of maintenance is extremely convenient.
Categorization of filtration
Divided into: air filter, liquid filter, network filter, light filter according to the filter medium
Schematic diagram of the filter structure
1.Air Filter
To make the contaminated air cleaned to the state required for production and life, that is to say, to make the air reach a certain degree of cleanliness. Air filter how to filter the air:
General air purification equipment to filter the air is probably divided into the following methods and steps.
1, multiple filters ---- prevent dust and germs in the air from entering the room
Multiple activated carbon filters effectively intercept dust and germs for filtering the air to ensure that the air entering the room is clean.
2, titanium oxide kills ---- degradation of indoor air pollution of formaldehyde, benzene and other organic toxic gases
Nanometer titanium dioxide activated by ultraviolet light to filter the air effectively degrade air pollution of formaldehyde, benzene and other organic toxic gases. of radioactive contamination in the air.
3, negative ion oxygenation ---- increase the oxygen in the indoor air to the right amount and keep the content stable
Negative ion generator to the indoor air oxygenation, to ensure that the air into the home to maintain a sufficient amount of oxygen, full of vitality, and Enhance the filtration of air>
4, PTC ceramic heating ---- heating indoor air to a comfortable temperature
PTC ceramic heating pads to the winter into the indoor air to assist in the preheating, properly increase the indoor temperature , thus filtering the air and making the home warm and comfortable.
5. Ultraviolet light sterilization ---- strong kill airborne epidemic virus bacteria
Ultraviolet light source has a strong kill airborne epidemic virus bacteria, so that people away from the source of infection, filtering the air, take care of the family's Healthy.
The filter is an indispensable device on the pipeline of conveying medium, which is usually installed at the inlet end of pressure reducing valve, pressure relief valve, water level valve or other equipments, and is used to eliminate the impurities in the medium, in order to protect the valves and normal use of the equipments. When the fluid enters the filter cartridge with certain specifications, the impurities are blocked, and the clean filtrate is discharged from the filter outlet, when the need for cleaning, as long as the removable cartridge is removed, re-installed after processing can be, therefore, the use of maintenance is extremely convenient.
2. Liquid Filter
It makes the contaminated liquid be cleaned to the state needed for production and life, that is, it makes the liquid reach a certain degree of cleanliness.
3. Network Filter
It is set up to block spam and make the information appearing on the computer screen conform to the requirements as much as possible. The same principle of absorption separates different colors of light
4. Light Filter
Absorbs some unwanted light.
In accordance with the installation mode:
Oil suction filter
Oil return filter
Line filter
In accordance with the performance of:
Line filter
Double tube filter
High-pressure filter
It should be a mesh filter, but in fact, there are many other kinds of filters. In fact, there are many kinds of filters, such as stacked filters, sand filters, carbon filters, etc., the main principle is to use the aperture of the filter media to retain smaller than the aperture of the media, of course, there are filter media also has a special effect of adsorption, etc. Most of the filter backwash is not so troublesome. Most of the filter backwash is not so troublesome, as long as the water from the end of the filtered water into the reverse backwash filter media can achieve a good backwash effect.
According to the industry is divided into:
Hydraulic oil filter: mainly used in the oil filtration industry, including suction filters, oil return filters, pipeline filters and so on.
Food filters: dust filters, air filters, middle and high efficiency filters.
Pharmaceutical filters: pharmaceutical filters, respiratory filters, blood filters, bacterial filters.
Introduction of the hydraulic system filter
The filter in the hydraulic system is called an oil filter, for more information, please see the entry: oil filter
Hydraulic oil often contains particulate impurities, which can cause wear and tear of the relative moving surfaces of the hydraulic components, the slide valve stagnation, throttle orifice clogging, so that the system working reliability is greatly reduced. In the system to install a certain accuracy of the oil filter, is to ensure that the material and structural form of the filter element, the oil filter can be divided into net, line gap type, paper cartridge type, sintered oil filter and magnetic oil filter. According to the oil filter placed in different locations, can also be divided into suction filter, pressure filter and return oil filter, taking into account the self-absorption performance of the pump, suction oil filter is mostly coarse filter.
(1) mesh oil filter
Net oil filter, the filter element to copper mesh as a filter material, around the opening of a lot of holes in the plastic or metal cylinder skeleton, wrapped with a layer or two layers of copper wire mesh, the filtration accuracy depends on the number of layers of copper mesh and the size of the mesh. This oil filter structure is simple, large flow capacity, easy to clean, but the filtration accuracy is low, generally used for hydraulic pump suction port.
(2) line gap type oil filter
line gap type oil filter, with steel or aluminum wire dense winding in the cylinder skeleton outside to form a filter element, relying on the small gap between the copper wire to filter out impurities mixed into the liquid. Its structure is simple, large flow capacity, filtration accuracy is higher than the net oil filter, but not easy to clean, mostly for the return oil filter.
(3) paper oil filter
Paper oil filter, its filter element for the plain or corrugated phenolic resin or wood pulp microporous filter paper made of paper core, the paper core around the hole in the tinned iron skeleton, to increase the strength. In order to increase the filtration area, the paper core is generally made into a folded shape. Its filtration precision is high, generally used for fine filtration of oil, but clogging can not be cleaned, must often replace the cartridge.
(4)Sintered oil filter
Sintered oil filter, its filter element with metal powder sintered from the use of microscopic holes between the particles to block the impurities in the oil through. Its filter element can withstand high pressure, good corrosion resistance, high filtration precision, suitable for high pressure, high temperature hydraulic system requiring fine filtration. Necessary means of normal operation of the hydraulic system.
Oilers according to its filtration accuracy (filtered impurities of the size of the particles) of the different, there are coarse filters, ordinary filters, precision filters and special fine filters of four kinds, which are able to filter out greater than 100 μm, 10 ~ 100 μm, 5 ~ 10 μm and 1 ~ 5 μm size of the impurities.
When choosing an oil filter, the following points should be considered:
(1) The filtration precision should meet the predetermined requirements.
(2) can be maintained in a longer period of time sufficient flow capacity.
(3) The filter element has enough strength and is not damaged by hydraulic pressure.
(4) The cartridge has good corrosion resistance and can work durably under the specified temperature.
(5) The cartridge is easy to clean or replace.
Therefore, the oil filter should be based on the technical requirements of the hydraulic system, according to the filtration accuracy, through-flow capacity, working pressure, fluid viscosity, operating temperature and other conditions selected its model.
2. Installation of the oil filter in the hydraulic system is usually installed in the following positions:
(1) to be installed in the suction port of the pump:
Pump suction is generally installed on the surface-type oil filter, the purpose is to filter out the larger particles of impurities in order to protect the hydraulic pump, in addition to the oil filter filter capacity should be more than twice the flow rate of pumps, the pressure loss of less than 0.02
(2) installed in the pump outlet oil:
The purpose of installing the oil filter here is used to filter out pollutants that may invade the valves and other components. Its filtration precision should be 10 ~ 15μm, and can withstand the working pressure and shock pressure on the oil, the pressure drop should be less than 0.35MPa. At the same time should be installed
Safety valves to prevent clogging of the oil filter.
(3) installed in the system on the return oil: this installation of indirect filtration. General and filter and install a back pressure valve, when the filter clogging reaches a certain pressure value, the back pressure valve opens.
(4) Installed in the system branch oil.
(5) separate filtration system: large hydraulic system can be dedicated to a hydraulic pump and oil filter composed of independent filtration circuit.
Hydraulic system in addition to the entire system required for the oil filter, but also often in some important components (such as servo valves, precision throttle valves, etc.) in front of a separate installation of a special fine oil filter to ensure that they work properly.
Other types of filters
Test bench filter
Used in the filter performance test bench above, this test bench in the test before the system should be strictly purified, so the test system and the test system for the service of the contamination of the injection system need to be equipped with a filter, which is the filter and the test of the filter is a different matter, the precision requirements, the requirements of the amount of dirt to be held to Than being tested by the filter precision, in order to distinguish between the two types of filters in the same test system, this filter is called the test bench filter, being tested by the filter is called the test filter.
General principles of filter selection:
1. Import and export diameter:
In principle, the import and export diameter of the filter should not be smaller than the inlet diameter of the matching pumps, generally the same caliber as the inlet pipeline.
2, nominal pressure:
In accordance with the highest possible pressure in the filter line to determine the pressure level of the filter.
3, the choice of the number of holes:
The main consideration is the size of the impurities to be intercepted, based on the media process requirements. Various specifications of the screen can intercept the size of the particle size check the table below "screen specifications".
4, filter material:
Filter material is generally selected and connected to the same process piping material, for different service conditions can be considered to choose cast iron, carbon steel, low alloy steel or stainless steel filter.
5. Calculation of filter resistance loss
Water filter, in the general calculation of the rated flow rate, the pressure loss of 0.52 ~ 1.2kpa
Y filter
Y filter (water filter) belongs to the coarse filter series of pipeline, can also be used for gas or other media large particles filtration, installed in the pipeline can be removed in the fluid, large solid impurities, so that machinery and equipment. Y filter (water filter) has the advantages of simple production, convenient installation and cleaning, and large dirt-holding capacity.
Filter Test Principle
※ Principle of Foaming Point Test: When the filter membrane and cartridge are completely moistened with a certain solution, and then pressurized by a gas source on one side (we have an air inlet control system inside the instrument, which can stabilize the pressure and regulate the air inlet), with the increase in pressure, the gas is discharged from the side of the membrane, and bubbles of varying sizes and quantities appear on the side of the membrane, which are judged by an instrument as the corresponding pressure value. The corresponding pressure value is the bubble point.
※ Diffusion flow test principle: Diffusion flow test means that when the gas pressure is 80% of the bubble point value of the cartridge, there is not a large amount of gas perforation, but only a small amount of gas is dissolved into the liquid phase of the diaphragm, and then diffused from the liquid phase to the gas phase on the other side, which is called diffusion flow.
※ Why the diffusion flow method is better: the bubble point value is only a qualitative value, from the beginning of the bubble to the final group of bubbles is a relatively long process, can not be accurately quantified. Measuring the diffusion flow value is a quantitative value, not only can accurately determine the integrity of the filter, but also reflect the porosity of the membrane, flow and effective filtration area and other aspects of the problem, which is why foreign manufacturers are now using the diffusion flow method to test the integrity of the reason.
※ Water intrusion test principle: water intrusion method is dedicated to the test of hydrophobic cartridge, hydrophobic membrane resistance to water, the smaller the pore size, the greater the pressure needed to squeeze the water into the hydrophobic membrane. So under a certain pressure, measure the water flow into the membrane to determine the pore size of the cartridge.
Filter industry standards
CJ/T 3068-1997 Polymer Sintered Microporous Tubular Filter
GB/T 13554-2008 High-efficiency Air Filter
GB/T 14295-2008 Air Filter
GB/T 14382-2008 Tee Filter for Piping <
GB/T 17486-2006 Hydraulic Filter
HG/T 21637-1991 Chemical Pipeline Filter
HG/T 4085-2009 Pressure Fiber Bundle Filter
QB/T 1166-1991 Duplex Filter
JB/T 7538-1994 Piping with Basket Filter
SY/T 0523-2008 Oilfield Water Treatment Filter
YY-T 0142-1994 Air Filter for Disposable Transfusion and Blood Transfusion Apparatus
JB-T 7374-1994 Air Filter for Pneumatic Application
HG-T 20570.22-1995 Pipeline Filter
JB-T 6417-1992 Air filter for air conditioning
JB-T 9044-1999 High gradient magnetic filter
YYY0286.1-2007 Single-use precision filtration infusion set
Filter Maintenance and Maintenance Methods
1. Coarse Filter
1. The core part of the filter is the filter core, which consists of the filter frame and stainless steel wire mesh, and the stainless steel wire mesh is a wear-and-tear part and needs special protection;
2. When the filter works for a period of time, certain impurities are deposited in the filter core, and at this time, the pressure drop increases and the flow rate decreases, so it is necessary to remove the impurities in the filter core in a timely manner;
3. When cleaning the impurities, special attention should be paid to the fact that the stainless steel wire mesh on the filter core should not be deformed or damaged. When cleaning impurities, special attention should be paid to the stainless steel wire mesh on the filter core, which should not be deformed or damaged; otherwise, the filter will be mounted on the filter, and the purity of the filtered medium will not reach the design requirements, and the compressor, pump, instrumentation and other equipments will be damaged;
4. If the stainless steel wire mesh is found to be deformed or damaged, it needs to be replaced immediately.
②, precision filter
1, the core part of the precision filter is the filter cartridge, the filter core is composed of special materials, is a wear and tear, need special protection;
2, when the precision filter work for a period of time, the filter cartridge blocked a certain amount of impurities, then the pressure drop increases, the flow rate will decline, need to remove the impurities in the filter in a timely manner, while cleaning filter;
4, if found deformed or damaged, the stainless steel wire mesh needs to be replaced immediately. Clean the filter element;
3. When removing impurities, pay special attention to the precision filter element, which shall not be deformed or damaged, otherwise, the filter element shall be loaded again, and the purity of the filtered medium shall not reach the design requirements;
4. Certain precision filters can not be used repeatedly for many times, such as the bag filter element and the polypropylene filter element, etc.
5. If the filter element is found to be deformed or damaged, it needs to be replaced immediately.
Overview: JCDG full-automatic backwashing and sewage disposal filter is a filter that completes the whole process of filtration, cleaning and sewage disposal automatically by utilizing the pressure difference between the front and back of the filter and relying on the automation element and electric actuator on the basis of ZPG-type backwashing filter; JCDG full-automatic backwashing and sewage disposal filter, in addition to all the performances of ZPG backwashing and sewage disposal filter, also realizes full automation, and automatically discharges sewage. JCDG full-automatic backwashing and sewage disposal filter has realized full automation, automatic filtration and sewage disposal and automatic backwashing and sewage disposal. In addition to differential pressure control, this model of filter also has timing control, and the time can be set according to the needs, so as to realize full-automatic backwashing, filtration and sewage disposal at regular intervals. And its cleaning and discharging are completed together in the online filtration process, without having to stop the water flow operation.
Structural form: CDG-type full-automatic backwashing and discharging filter consists of shell, stainless steel filter cylinder, impurity collection section, electric impurity discharge port, electric water flow steering butterfly valve, detecting mechanism, actuator and control box. It is divided into straight-through type and angle-through type according to the different installation forms and water flow directions.
Working Principle
1. Timing backwashing and sewage discharge, can be set for 2-24 hours of action, when the timing time is up, the electric actuator opens the sewage, the filter for sewage for 30-60 seconds, and then the electric actuator will rotate the steering butterfly valve by 90 degrees to the position of blocking the filter cartridge, change the path of the water flow, and carry out the backwashing and sewage discharge for 30-60 seconds, and then the steering butterfly valve is reset, and the sewage discharge continues for 3-5 seconds, and then the valve is closed and the water flow direction is changed. 3-5 seconds, and then close the sewage outlet.2. Differential pressure control sewage, differential pressure controller action value can be set to 0.03-0.07MPa, when the pressure difference between the front and rear of the filter reaches the set value of the differential pressure controller, the differential pressure controller acts, the filter sewage valve opens, and the end of the 30-60 seconds, the steering butterfly valve is reset, and continues to be discharged for 3-5 seconds, and then closes the sewage valve.3. Manual control, by means of the buttons on the control box, it is possible to directly control the cleaning, sewage removal and discharge of water, and then close the sewage valve. button, you can directly control the cleaning and discharging.
Technical Parameters
Working Pressure: 1.6MPa; Working Temperature 150 degrees; Filter Specification 8-80 mesh; Resistance Loss 2.0-6.0KPa; Flushing Time 30-60 seconds Electric Actuator Power Supply 380VAC'50Hz; Controller Power Supply: 220VAC,50Ha;380VAC,50Hz.
Performance characteristics and installation: 1, JCDG-type automatic backwashing and sewage filter is convenient in operation and management, high filtration speed, simple and reliable flushing, and strong backwashing ability. 2, Timing or differential pressure control mode, can be fully automatic filtering and sewage cleaning, and ensure the efficient use of the filter. 3, the control box is equipped with the filter's working status, cleaning status, and fault status indication, and the output of the corresponding signal, and the operation is simple and convenient. 4, the flushing, cleaning, and fault status indication, and the corresponding signal output. Flushing and backwashing time can be adjusted, and the amount of sewage discharge is less than 10% of the normal flow rate.5. It can be installed horizontally or vertically in the system pipeline.6. The control box is installed in the control room or near the filter.7. Wiring is carried out in accordance with the wiring terminal labeling and wiring diagram shown in the control box, and attention is paid to the normal grounding of the grounding wire to ensure safety.