Large Offline Bag Filter

Large offline bag filter is an effective dust removal equipment designed for large industrial production lines. Its core advantages include high air flow processing capacity, offline dust cleaning without secondary pollution, and stable continuous operation. It is widely used in industries such as power, building materials, metallurgy, and chemical engineering. It can handle gases with dust concentration ≤ 3000g/m ³ and air flow of 10000-200000m ³/h, and has a filtration efficiency of over 90% for dust particles larger than 0.1 μ m. It is a key equipment for large factories to achieve centralized dust control and meet emission standards.

From the perspective of structural design, the equipment adopts a multi unit box structure, with the core consisting of five parts: multi chamber filter box, offline ash cleaning system, inlet air flow equalization device, ash unloading and conveying system, and PLC intelligent control system. The overall area can reach tens to hundreds of square meters, and customized installation is required according to the production line layout. The filter box is the core, usually divided into 4-16 independent filter chambers, each with hundreds or thousands of filter bags, with a length of 3-6m. The filter materials are selected from high temperature resistant (based on actual reports) and corrosion-resistant (based on actual reports) PPS, PTFE, Nomex and other special materials, suitable for complex working conditions such as boiler flue gas and cement kiln dust; The installation of the filter bag adopts a spring expansion ring seal to confirm that there is no air leakage between the filter chambers. At the same time, each filter chamber is equipped with an independent maintenance door to facilitate the replacement and maintenance of the filter bag. The offline dust cleaning system is the core innovation point. Each filter chamber is equipped with independent inlet valves, outlet lifting valves, and pulse blowing components, with a blowing pressure of 0.4-0.6MPa. During dust cleaning, the inlet and outlet valves of a single filter chamber are closed to make it "offline" from the main airflow, and then pulse blowing is carried out to avoid secondary adsorption of dust; The inlet air flow equalization device evenly distributes the high concentration dusty gas to each filter chamber through the wind deflector, guide pipe, and porous distribution plate, preventing local filter bag overload and damage. The ash unloading and conveying system consists of a conical ash hopper, a star shaped discharge valve, a screw conveyor, and a bucket elevator. The ash hopper is equipped with heating and arch breaking devices to avoid dust condensation and bridging, and to ensure continuous discharge and centralized transportation of dust; The PLC intelligent control system can monitor the resistance, temperature, and cleaning status of each filter chamber in real time, achieve fully automatic offline cleaning, fault alarm, and interlock control, and support remote operation and maintenance.

Its working principle revolves around the closed-loop process of "room filtration offline ash cleaning centralized ash unloading": dusty gas enters the equipment from the main inlet, is distributed to each filtration chamber through the flow equalization device, and the dust is trapped on the outer surface of the filter bag. The purified gas passes through the filter bag and enters the clean air chamber, and is discharged from the main outlet through the outlet lifting valve; When the resistance of a certain filter chamber rises to the set value (1500-1800Pa), the PLC system controls the inlet valve of the filter chamber to close and the outlet lifting valve to fall, cutting it off from the main airflow (offline state). Then, the pulse blowing component starts, and compressed air is sprayed into the filter bag at high speed, causing the filter bag to instantly expand and shake, and the dust falls into the ash hopper after peeling off; After the dust cleaning is completed, the inlet and exhaust valves are reopened, and the filter chambers return to the filtering state. Each filter chamber alternates offline dust cleaning in sequence, without interrupting the overall dust removal operation, to protect the continuous operation of the production line; The dust in the ash hopper enters the conveying system through the discharge valve and is ultimately collected or recycled.