Oil purification process
Oil filters are designed to remove contaminants and particles from motor, transmission, lubrication, hydraulic, or any other kinds of oils and fluids.
The filter’s principle of operation is based on incoming pressurized oil from the pump being divided into a number of flat streams. Particulate pollutants move together with the oil. Then they enter annular spaces and remain there or on the surface of the filter, and the oil is pressed through the slots in the plates and gaskets within the filter. Particle size that are smaller than the clearance pass through the filter with the flow of oil. This is the difference between the use of non-identical types of filters – in the throughput of such devices.
There are two main types of filters: coarse and fine. Coarse filters are full-flow and process the entire volume of the liquid pumped.
The filter element typically consists of a set of filter plates and spacers. Oil passes through the gaps between the plates where contaminants are retained. Also included in these gaps are fixed cleaning plates, secured on a rod of rectangular cross section.
A housing in which filters are placed is divided into two isolated chambers: one for purified and one for unfiltered oil. In the past, turning the handle on the rod removed dirt which fell into the sump.
Recently, units which use coarse filters are are equipped with scrubber blades on a fixed stand, for filter slots. The blades enter the slots. To remove particles from the filter surface, a handle is pulled several times, rotating the plates around the fixed blades. The accumulated particles fall into the dirty oil chamber and fall to the bottom, not contamination filtered oil.
Improving the quality of oil by using modern purification systems requires a certain formulation of stabilizing and anti-oxidation additives and at least two stages of filtration through fine and coarse filters.
Most manufacturers of oil purification equipment increase the amount of filters in their units and also include fine filtration. Coarse filter must be replaced on a regular basis, since they can become clogged and will not let the oil through.
The coarse filter is a full-flow filter. However, coarse filters usually cannot retain particles smaller than 0.15 mm. Coarse filtration alone cannot guarantee oil purity.
Most often the manufacturers use a combination of filters in their units, improving the efficiency of purification and capture contaminants from the oil.