Classification of hepa filters
The filter in the hydraulic system is called the oil filter. For details, please refer to the entry: oil filter
The hydraulic oil often contains granular impurities, which will cause the hydraulic components to be relatively The wear of the moving surface, the sticking of the spool valve, and the blockage of the throttle orifice greatly reduce the reliability of the system. The installation of a certain precision oil filter in the system is to ensure that according to the material and structure of the filter element, the oil filter can be divided into mesh type, line gap type, paper filter element type, sintered oil filter and magnetic oil filter, etc. . According to the different positions of the oil filter, it can also be divided into suction filter, pressure filter and oil return oil filter. Considering the self-priming performance of the pump, the oil suction oil filter is mostly a coarse filter.
(1) Mesh oil filter
Mesh oil filter, its filter element is made of copper mesh as filter material, and a plastic or metal cylindrical skeleton with many holes around it It is covered with one or two layers of copper wire mesh, and its filtration accuracy depends on the number of copper mesh layers and the size of the mesh. This kind of oil filter has the advantages of simple structure, large flow capacity and convenient cleaning, but low filtration precision, and is generally used for the oil suction port of hydraulic pump.
(2) Line-gap oil filter
Line-gap oil filter, the filter element is composed of steel wire or aluminum wire tightly wound on the outside of the cylindrical skeleton, relying on copper wire The tiny gaps between the filaments filter out impurities mixed in the liquid. The structure is simple, the flow capacity is large, and the filtering precision is higher than that of the mesh oil filter, but it is not easy to clean, and most of them are return oil filters.
(3)Paper oil filter
Paper oil filter, the filter element is a paper core made of plain or corrugated phenolic resin or wood pulp microporous filter paper. The paper core is wrapped around a skeleton made of perforated tinned iron for strength. In order to increase the filtering area, the paper core is generally made into a folded shape. It has high filtration precision and is generally used for fine filtration of oil, but it cannot be cleaned after clogging, and the filter element must be replaced frequently.
(4) Sintered oil filter
Sintered oil filter, the filter element is sintered with metal powder, and the pores between the particles are used to block the impurities in the oil pass through. The filter element can withstand high pressure, has good corrosion resistance and high filtration precision, and is suitable for high pressure and high temperature hydraulic systems requiring fine filtration. Necessary means for the hydraulic system to work properly.
According to its filtration precision (the size of the particles that filter out impurities), there are four types of oil filters: coarse filter, ordinary filter, precision filter and special precision filter, which can filter out more than Impurities of 100μm, 10～100μm, 5～10μm and 1～5μm size.