The high dust removal efficiency of the bag filter is inseparable from its dust removal mechanism. When the dusty gas enters the ash hopper through the deflector through the air inlet pipe at the lower part of the dust collector, due to the impact of the deflector and the reduction of the gas velocity, the coarse dust will fall into the ash hopper, and the remaining fine dust will enter the filter bag room with the gas. Due to the inertia, diffusion, barrier, hooking, static electricity and other effects of the filter material fiber and fabric, the dust will be trapped in the filter bag, and the purified gas will escape out of the bag and be discharged through the exhaust pipe. The accumulated dust on the filter bag is removed by gas back washing method. The removed dust is discharged to the ash hopper and discharged to the ash conveying device through the double-layer ash unloading valve. The accumulated dust on the filter bag can also be removed by spraying pulse air flow, so as to achieve the purpose of ash removal. The removed dust is discharged by the ash discharge device.

The top of the outlet of each row of filter bags is equipped with a blowing pipe, and the lower side of the blowing pipe is directly opposite to the filter bag. A pulse valve is set on each blowing pipe and connected with the compressed air bag. During ash cleaning, the electromagnetic valve opens the pulse valve, and the compressed air is sprayed by the ash cleaning control device (differential pressure or timing, manual control) to open the electromagnetic pulse blowing according to the set procedure, The compressed gas passes through each pulse valve in sequence in a very short time and induces the air several times as much as the injected air into the filter bag through the nozzle on the injection pipe to form an air wave, which causes the filter bag to undergo rapid expansion and impact vibration from the bag mouth to the bottom, resulting in a strong ash cleaning effect. The purpose of ash cleaning can be achieved by blowing once. Therefore, the ash cleaning cycle is prolonged, the energy consumption for ash cleaning is reduced, and the air consumption can be greatly reduced. At the same time, The fatigue degree of the filter bag and the pulse valve is also correspondingly reduced, thereby doubling the service life of the filter bag and the valve plate.

At the lower part of the box, it is mainly used to accommodate the bag cage and the dust removal cloth bag to form a filter space. According to the requirements, it is divided into several chambers according to different specifications and separated by partitions to prevent mutual interference between the chambers during the ash removal and form a certain settlement space.

It can be divided into flat bags (trapezoidal and flat) and circular bags (cylindrical). The bag structure can increase the filter area of the air inlet, which is 3-5 times larger than the conventional plate filter; The glass fiber needle felt material has the advantages of high filtration efficiency, easy dust peeling, long service life, etc. the vertical installation makes the pulse ash cleaning easier, and avoids the "bridging" phenomenon of ash cleaning when the filter bag is installed horizontally

The pulse air flow is used for ash blowing and cleaning. The technology of pulse blowing and cleaning by stopping air in different rooms overcomes the shortcomings of conventional pulse dust collector and reverse blowing dust collector in different rooms. It has good ash cleaning capacity, low emission concentration, low air leakage rate, low energy consumption, less steel consumption, less land occupation, stable operation and good economic benefits.

The ash hopper is arranged at the lower part of the bag chamber, which has the function of collecting dust and serving as the air inlet header. The ash hopper has a large volume, which can reduce the air flow speed. In addition, the change of the air flow direction makes the coarse dust particles separated here. The lower part of the ash hopper is provided with conveying equipment such as screw conveyor or air chute. The outlet is also provided with air lock equipment such as rotary unloader or flap valve, which can continuously discharge the ash.

The air inlet and outlet can be divided into two types. One is cylindrical, which is directly welded on the side plate of the ash hopper. The air outlet is arranged at the lower part of the box and the side of the bag chamber, and is connected with the inside of the box through the lifting valve plate hole; The other is that the air inlet and outlet are integrated and arranged on the side of the bag chamber, between the box and the ash hopper. The middle is separated into two airtight parts, namely, the air inlet and the air outlet. Although the structure is larger, the air flow distribution is uniform, and the pre dedusting effect in the ash hopper is good. It is suitable for the occasions with large dust concentration in the flue gas.