1. Basic types of filters
Filters can usually be divided into the following types according to different working principles and usage occasions:
1. Y-type filter
Y-type filter is the most common type of filter, usually used for small and medium-caliber pipes. Its structure is in the shape of a "Y", suitable for installation in the horizontal part of the pipe, and is mainly used to remove particulate impurities in the pipe. Y-type filters usually have higher filtration efficiency, are easier to clean, and are suitable for lighter filtration needs.
2. T-type filter
T-type filters are similar to Y-type filters, but their installation method and structure are slightly different, and they are usually used in vertical pipes. T-type filters can provide filtering with a larger flow rate and are suitable for systems with larger flow rates.
3. Cartridge filter (basket filter) Cartridge filter, also known as basket filter, is commonly used in medium-to-high flow and high-precision filtering occasions. Its filter element is usually a metal mesh basket, which can effectively remove larger particulate matter in the pipeline. Cartridge filters are commonly used for filtering liquids or gases, are easy to clean, and have a high flow handling capacity.
4. Plate and frame filter Plate and frame filters are suitable for high-precision filtering occasions, and the filter media can be various fibers, filter cloths, etc. Plate and frame filters are widely used in liquid filtration, especially when the liquid contains particles such as suspended matter, grease or sediment, and can provide better filtering effects.
5. Automatic cleaning filter Automatic cleaning filter regularly cleans the filter element through an automated control system, and is suitable for treating fluids with poor water quality and many impurities. Automatic cleaning filters are often used in industrial water treatment, sewage treatment, mineral processing and other occasions that require efficient cleaning.
6. Bag filter
Bag filter is a device that uses filter bags for filtering. It is usually used for filtering liquids, especially when the liquid contains a large number of particles or impurities. It has high filtering accuracy and compact structure, and is suitable for chemical, pharmaceutical, food and other industries.
7. Swirl filter
The cyclone filter generates centrifugal force through cyclone, so that impurities in the fluid are thrown to the outer wall of the filter, thereby separating particles. Cyclone filters are often used in large flow and low-precision filtering occasions.
2. Key factors in purchasing filters
When purchasing filters, the following factors need special attention:
1. Media type
The main function of the filter is to remove impurities in the fluid. Therefore, the media type is the primary consideration for selecting filters. Different fluids have different requirements for filter materials, filtering accuracy and working pressure.
- Water: Commonly used in water treatment systems, select filters made of stainless steel or plastic.
- Oil: Oil media may contain larger particle impurities, and it is necessary to select filters with a sturdy structure and can prevent oil clogging.
- Gas: For gases, choose corrosion-resistant and high-temperature resistant filters, especially in chemical plants.
- Chemicals and corrosive media: It is necessary to choose corrosion-resistant and high-temperature resistant materials, such as stainless steel, alloy steel, etc.
2. Filtration accuracy
The accuracy of the filter directly determines its filtering effect. According to the impurity size of the filter medium and the requirements of the pipeline system, choose the appropriate filtration accuracy.
- Coarse filtration: For the filtration of coarse particle impurities, you can choose a larger pore size, such as 200 mesh, 100 mesh, etc.
- Precision filtration: For the filtration of fine particles, choose a smaller pore size, such as below 200 mesh, or even up to the micron level.
3. Flow and caliber
The flow and caliber of the filter must match the specifications of the pipeline. A filter that is too small will result in insufficient flow, while a filter that is too large will cause unnecessary waste. Common filter calibers are 1/2", 1", 2", 4", etc. When choosing, you need to match it according to the diameter and flow requirements of the pipeline.
4. Working pressure and temperature
The filter needs to operate normally within the specified working pressure and temperature range. Different types of filters have different pressure and temperature resistance. When purchasing, you need to choose the appropriate model according to the working environment. For example, some high-temperature and high-pressure industrial environments require specially designed filters, and high-temperature resistance and corrosion resistance are very important.
5. Material selection
The material of the filter directly affects its durability and adaptability. Common filter materials include:
- Cast iron: Suitable for low-temperature and low-pressure environments, low cost.
- Carbon steel: Suitable for normal temperature and pressure environments, suitable for general liquids and gases.
- Stainless steel: Suitable for highly corrosive and high-temperature resistant occasions, such as the chemical and food industries.
- Plastic: Suitable for low-temperature, non-corrosive fluids, low cost.
6. Cleaning and maintenance
The cleaning and maintenance methods of the filter directly affect its service life and filtration efficiency. Some filters are designed with automatic cleaning functions, which can reduce manual intervention and improve the automation of the system. When choosing a filter, you can decide based on the difficulty of cleaning, maintenance cycle, and requirements for the working environment.
7. Installation location and method
The installation location of the filter is usually at the inlet or outlet of the pipeline system. According to the layout of the pipeline, choose the appropriate filter structure and installation method:
- Flange connection: Suitable for large-diameter, high-pressure pipelines.
- Clamp connection: Suitable for small and medium-diameter pipelines, easy to install and low cost.
- Threaded connection: Suitable for small-diameter pipelines, easy to install.
8. Brand and quality of filters
Choosing filters from well-known brands can guarantee quality and after-sales service. Brands usually have perfect after-sales support, and the quality and technology are relatively guaranteed.
3. Common applications of filters
Filters are widely used in various occasions where impurities need to be filtered, equipment needs to be protected, and fluid quality needs to be improved. Common application areas include:
1. Water treatment: Used in municipal water supply, sewage treatment, seawater desalination and other fields to remove sediment, impurities and particulate matter in the water.
2. Oil and gas: In oil and gas pipelines, prevent impurities in the pipeline from entering equipment and systems.
3. Chemical industry: used for filtering liquids, gases and raw materials in chemical reactions to prevent impurities from affecting the production process.
4. Pharmaceutical industry: used to filter impurities in the production process of drugs to ensure the quality of drugs.
5. Food and beverage: used to filter liquids, raw materials, etc. in food production to ensure the purity of the product.
6. Heating, ventilation and air conditioning (HVAC): used in air conditioning and heating systems to filter impurities in pipes and protect equipment operation.
7. Industrial liquid: in liquid cooling, hydraulic systems, etc., filter solid impurities in liquids to ensure the normal operation of equipment.
4. Selection case
Suppose a factory needs to purchase a filter for filtering cooling water, requiring high filtration accuracy and automatic cleaning function, and the working environment temperature is high. The following options can be considered:
- Material: Choose stainless steel or alloy steel material, which can withstand high temperatures.
- Type: Choose an automatic cleaning filter to reduce maintenance work.
- Precision: Choose a higher precision filter, such as a 100-mesh filter, which can remove smaller impurities.
- Flow and caliber: Choose the appropriate filter model according to the pipeline flow and caliber to ensure the normal operation of the system.
5. Conclusion
When purchasing a filter, you need to consider factors such as filtration accuracy, material, flow, working pressure, temperature, etc. By choosing the right type of filter, you can effectively remove impurities in the fluid, improve system operation efficiency, and protect the life of the equipment.