Filter: in equipment operation, industrial products such as hydraulic oil, transformer oil, turbine oil, frozen oil, lubricating oil.
Resistance in the process of using a variety of reasons such as fuel will be mixed in some impurities, major impurities are mechanical impurities, metal particles, and water, etc.
These impurities can cause corrosion speed up, increase the mechanical wear, reduce work efficiency, make oil deterioration, reduce the service life of the equipment, serious when producing oil blockage caused by accidents.
Hydraulic oil filter element is installed in the equipment, filtering parts, the role of the filter element is to filter out the hydraulic system special oil in the metal particles, impurities, etc. to ensure that the oil into the main engine clean, to protect the safety of the main engine equipment, so as to improve the safety and reliability of equipment operation.
At the same time, it can also greatly improve the service life of each component of the equipment and improve the efficiency of the equipment. Therefore, the filter element is indispensable in the operation of many devices.
There are many kinds of filter elements, mainly depending on the equipment requirements and filter medium.
In the hydraulic system, there are five common filter elements:
1. Paper filter element
The filter core is a paper core made of plain or corrugated phenolic resin or wood pulp microporous filter paper. The paper core is surrounded by the skeleton made of tin iron with holes to increase the strength. Due to the low strength of the paper core, it cannot be cleaned and needs to be replaced frequently. Therefore, it is generally used in pressure tubing with high filtration accuracy.
2. Sintered filter element
Sintered filter element, sintered with metal powder, using micropores between particles to block impurities in the oil through. Simple manufacturing, high strength, large oil capacity, high filtration accuracy (up to 0.005 ~ 0.1mm), and low-pressure drop, so often installed in the throttle valve or speed control valve inlet pipeline.
3. Line-gap filter element
The wire-gap filter element is composed of steel wire or aluminum wire tightly wound around the outside of the tubular skeleton, and the impurities mixed with the liquid are filtered out by the tiny gap between the copper wire. Its structure is simple, flow capacity is large, filtering accuracy is higher than the screen filter, but it is not easy to clean, mostly oil return filter core.
4. Screen filter element
Mesh filter element, the filter element to galvanized mesh as filtering material, in the surrounding open a very porous plastic or metal cylinder frame, covered with a layer or two layers of copper wire mesh, the filtration accuracy depends on the number of layers and mesh size of the galvanized mesh. This kind of oil filter has a simple structure, large flow capacity, easy cleaning, but low filtration accuracy, and is generally used for oil suction of the hydraulic pump.
5. Chip filter element
The filter element of the oil filter is generally made of galvanized mesh. The oil filtering accuracy depends on the size of the gap between galvanized mesh, but because of the low filtering accuracy of the chip filter element, it has been less used in the hydraulic system.
Filter element products can be used normally, must comply with the parameters of the working environment, when the hydraulic oil into the hydraulic system, cleaning is the primary problem. Hydraulic pollution is not what people think of as an eye – to – eye smudgy phenomenon, but seems to be clean, in fact, the oil is filled with thousands of pollution particles.
Poor quality hydraulic oil filter filtering effect is poor, can not effectively prevent dirt and other impurities into the hydraulic system, if entered the tiny impurity particles in the hydraulic system, they will scratch hydraulic pump (drivers) generally adopts high precision plunger pump, the wear lead to clearance, hydraulic pressure, resulting in inability to work), jammed valves, blocking oil mouth, causing malfunction.
The parameters of the general filter element include the following aspects:
1. Working pressure: 0.05MPa-0.6MPa. It is very important for the internal and external wire mesh in the filter element structure to have a certain strength.
2. Working temperature: 5℃-40℃(special temperature can be customized)
3. Filter element interface: flat pressing type and insertion type, determined according to the design standards of the machine.
4. Filtration accuracy: 3mm – 100mm filtration accuracy refers to the filtration ability of the filter material to pollutants with particles of different sizes. In general, the higher the filtering accuracy, the shorter the filter element’s life, because there are too many impurities on the screen surface, resulting in the shortening of the filter element’s service life.
5. Number of filter elements: 1-180
6. Length of filter element: 10 “-50”, fit to ensure correct installation of the filter element.
According to the different equipment, the installation position of the filter element is different, the function is also different.
1. Install in the suction pipe of the hydraulic pump
To prevent impurities into the hydraulic pump to avoid hydraulic pump damage, but the filter requires a small resistance and a large oil capacity, so the filter installed filter filtering accuracy is always lower.
2. Install on the outlet pipeline of the hydraulic pump
It protects all hydraulic components except the hydraulic pump. Filters can be various forms of sophisticated filters. Because it is working under high pressure, need to have a certain strength and stiffness, the weight of the filter greatly increased, to avoid the hydraulic pump overload due to the filter blockage, the filter parallel sequence valve as a safety valve, the operating pressure is slightly higher than the maximum allowable pressure difference of the filter.
3. Install in the return pipeline
At this point, the filter does not bear high pressure, but the hydraulic system will produce a certain amount of backpressure. This installation can not directly protect the hydraulic components, but can often eliminate impurities in the system.
4. Separate filtering system
The large hydraulic system can be specially equipped with a hydraulic pump and oil filter to form an independent filter circuit. In addition to the oil filter required by the whole system, a special oil filter is often installed in front of some important components to ensure their normal operation.
5. Install on the tributary pipeline
Only a portion of the oil passes through the filter, reducing the size of the filter, but not completely ensuring the safety of the hydraulic components.
In a word, all considerations of filter element selection are to make the whole system and all components have an ideal use environment, reduce the influence of various adverse factors in the system operation on the whole system, to improve the security and reliability of system operation.
At the same time, it also greatly improves the service life and efficiency of each component.
The key is to make sure the oil is clean at the input. The operating environment of the whole system is evaluated according to the parameters of the oil, and the influence of each link on the whole system is taken into comprehensive consideration. Choose the most economical and reliable filter element, which is suitable for its own production and use, and carry out good daily maintenance and cleaning of the filter element to ensure the safe, reliable and efficient operation of the system.
– Inborn Filter