Working principle
After the dust gas of the cartridge filter enters the dust hopper, due to the sudden expansion of the air flow section and the action of the air flow distribution plate, some coarse particles in the air flow settle in the ash hopper under the action of dynamic and inertial forces; After the fine and low density dust particles enter the filter chamber, the dust is deposited on the surface of the filter material through the combined effect of Brownian diffusion and screen filtration. The purified gas enters the purification chamber and is discharged by the exhaust pipe through the fan.

Design features of cartridge filter
The resistance of the cartridge filter increases with the increase of the thickness of the dust layer on the surface of the filter material. When the resistance reaches a certain specified value, the ash shall be removed. At this time, the PLC program controls the opening and closing of the pulse valve. First, the lifting valve of the first chamber is closed to cut off the filtered air flow, and then the electromagnetic pulse valve is opened. The compressed air expands rapidly in the upper box for a short time and flows into the filter cartridge, which causes the expansion and deformation of the filter cartridge and produces vibration. Under the effect of the reverse air flow, the dust attached to the outer surface of the filter bag is stripped and falls into the ash hopper. After ash cleaning, the electromagnetic pulse valve is closed, the lifting valve is opened, and the chamber returns to the filtering state. The cleaning process is carried out in each room in turn, and the cleaning cycle is from the beginning of cleaning to the beginning of the next cleaning. The dust discharge

Scope of application
The cartridge filter is widely used in the ventilation and dust removal of mining, metallurgy and other industries. It is a new type of dust collector developed on the basis of bag filter. It adopts new filter material (cartridge), and has the advantages of high efficiency (above 99.9%), low resistance, simple maintenance and management, small volume and so on. However, the non-uniform flow field in the cartridge filter often leads to the reduction of filtration efficiency and the shortening of the service life of the cartridge. Therefore, it is of great practical significance to improve the internal flow field uniformity of dust collector.

Compared with the filter bag, the length of the filter tube is short, but the filter area is large, and the structure has its particularity. The CFD software is used to simulate and optimize the flow field in the cartridge filter_ The accuracy of optimization design can reduce the research cost.
 

Air filter element
The selected air filter element should match the power, economy and performance of the original engine.

(1) Rated air intake
The air chlorine flow rate in the technical parameters of the filter element should be greater than the rated air intake of the engine.

(2) Filter material
There are requirements for the thickness, anti tension, original intake resistance and filtration accuracy of the filter material. The air filtration accuracy of diesel engine should be 5 μ m, and that of domestic diesel engine should be less than 20 μ M. The filtration accuracy of filter paper is 2 μ m, that of ordinary filter paper is 30 μ m, and that of domestic filter paper is only 80 μ M.

(3) Filter performance test
The flow resistance (pressure drop) test is used to measure the air flow pressure loss (flow resistance or flow pressure chamber curve).

The original filtration efficiency test can calculate the dust collection efficiency of the filter element, and the dust reduction rate of the normal filter element should be more than 99%.

In the dust storage capacity test and cumulative efficiency test, too much dust accumulated in the filter element results in blockage and increase of air inlet resistance. When the engine power is reduced by 5% or the fuel consumption is increased by 5%, the intake resistance is a value. When this value is reached, clean or replace the filter element. During the test, the dust storage capacity of the filter element is the ash weight when the inlet resistance or pressure drop reaches 7-46kpa, and the filtration efficiency during the test is the cumulative efficiency.

The pressure difference between the inlet and outlet when the air flow passes through the filter element should not exceed 3.2kpa, and the power will decrease and the engine will emit black smoke.

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