Baghouse Filter Working Principle

The dust-laden gas is taken from the lower intake pipe of the precipitator. When the deflector enters the ash hopper, the coarse dust will fall into the ash hopper due to the collision of the baffle and the decrease of the gas velocity. The remaining fine particulate dust enters the filter bag chamber with the gas. Due to the inertia, diffusion, blocking, hooking, static electricity of the filter fiber and the fabric, the dust is retained in the filter bag. The purified gas escapes out of the bag and is discharged through the exhaust pipe. The ash on the filter bag is removed by gas backwashing. The removed dust is discharged to the ash hopper and discharged to the ash conveying device through the double-layer ash discharging valve. The ash on the filter bag can also be removed by blowing a pulsed airflow to achieve the purpose of cleaning. The dust that has been removed is drained by the ash discharge device. The high dust removal efficiency of the bag filter is also inseparable from the filter material. The performance and quality of the filter material is directly related to the performance of the bag filter and the length of its service life. The filter material is the main material for making the filter bag. Its performance and quality promotes the advancement of bag dust removal technology, affecting its application range and service life.

The filter type dust removing device includes the baghouse filter and the particle layer dust remover. The baghouse filter usually uses a filter bag made of organic fiber or inorganic fiber fabric as a filter layer. The latter filter layer is composed of particles of different particle sizes, such as quartz sand, river sand, ceramsite, slag and the like. With the repeated adhesion of the powder to the outer surface of the filter bag, the powder layer is continuously thickened, and the resistance value of the bag filter is also increased. The pulse valve diaphragm sends out a command, and the pulse valve opens when the left and right are submerged, and the compressed air in the high-pressure air bag passes. If there is no dust or a certain degree, the mechanical cleaning work will stop working.

The gas purification mode of the low pressure pulse bag type dust collector is an external filter type. The dust-containing gas enters each unit filter chamber from the draft tube. Due to the sufficient and reasonable airflow of the bottom of the filter bag at the bottom of the air inlet through the proper diversion and natural flow distribution, the air distribution throughout the filter chamber is even. The particulate dust in the dust-containing gas falls directly into the ash hopper after being separated by natural sedimentation, and the remaining dust is guided by the diversion system, and enters the middle tank filtration zone with the airflow, and is adsorbed on the outer surface of the filter bag. The filtered clean gas permeating filter bag is discharged through the upper tank and the exhaust duct.

The filter bag is blown and cleaned with compressed air. The cleaning mechanism is composed of a gas bag, a blowing pipe and an electromagnetic pulse control valve. A spray pipe is mounted on the top of each filter bag outlet in the filter chamber. The lower side of the blowing pipe is provided with a blowing port at the center of the baghouse cages. Each of the blow pipes is provided with a pulse valve and communicates with the compressed air air bag. When cleaning, the solenoid valve opens the pulse valve, and the compressed air is sprayed by the cleaning control device (differential pressure or timing, manual control) to open the electromagnetic pulse injection according to the setting program. The compressed gas induces several times the amount of air injected into the filter bag through the nozzles on the injection pipe through the respective pulse valves in a very short time in order to form an air wave. The filter bag is subjected to sharp expansion and shock vibration from the mouth to the bottom, resulting in a strong cleaning effect and shaking off the dust on the filter bag.