How to protect the cloth bag when dealing with high-temperature flue gas?

When dealing with high-temperature flue gas,the protection of the dust removal bag should first focus on the source adaptation and structural reinforcement of the filter material and supporting components,in order to avoid the basic damage caused by high temperature from the material level.Based on the long-term operating temperature and composition of the flue gas,specialized high-temperature filter media such as PPS,aramid 1313,PTFE,or Flumes should be selected.PPS is suitable for high-temperature,high corrosion,and high humidity conditions,aramid 1313 is suitable for high-temperature,high erosion,and no strong corrosion scenarios,and PTFE is used for extreme high-temperature and strong corrosion conditions;All high-temperature filter bags are recommended to be coated to prevent high-temperature fine dust from entering the pores of the filter material.In high humidity conditions,waterproof and oil resistant processes are used.The finished filter bags are sewn with high-temperature and corrosion-resistant threads,and stainless steel or high-temperature rubber wear-resistant bottom rings are installed at the bottom.The air inlet is thickened.The matching cage bone is preferably made of 304 stainless steel or high-temperature galvanized spray material.All sharp corners and burrs are polished and the bottom ring is reinforced to ensure a tight fit with the filter bag without looseness,avoiding shaking,friction,and abrasion of the filter bag under high temperature.

The precise control of flue gas temperature is the core of high-temperature bag protection,and dual measures of anti overheating and anti condensation should be taken to avoid irreversible damage to the filter bag caused by abnormal temperature.Online high-temperature thermometers with sound and light alarms are installed at key positions of the dust collector inlet and flue to monitor temperature in real time,ensuring that the long-term operating temperature of the flue gas is 10-20℃lower than the rated temperature resistance of the filter material.At the same time,cold air injection valves and high-temperature bypass valves are installed in the flue.In case of instantaneous overheating such as furnace explosion,dry cold air is immediately injected to cool down or high-temperature flue gas is diverted away.Thicken the insulation and heat tracing treatment of the flue,dust collector shell,and ash hopper.Seal the flanges,manhole doors,and other parts tightly with high-temperature sealant to prevent cold air from infiltrating and causing condensation of the flue gas,ensuring that the flue gas temperature is always 20-30℃above the dew point;During low load operation,close some of the filter chambers to increase the single chamber wind speed,prevent local cooling and condensation,and synchronize the insulation and heat tracing of the ash hopper to avoid high-temperature dust bridging.

The optimization of equipment structure and fine control of operation and maintenance can further reduce problems such as airflow erosion and dust removal damage under high temperature conditions,and extend the service life of the bag.Install high-temperature wear-resistant guide plates and airflow distribution plates at the inlet of the dust collector,and set up a baffle in front of the filter bag inlet to buffer high-speed high-temperature airflow and avoid direct impact on the bottom of the filter bag and the inlet,causing scouring and wear;The dust cleaning system prioritizes offline cleaning methods,controlling the compressed air pressure at 0.4-0.5MPa and the spraying time at 0.1-0.15s.The cleaning frequency is intelligently adjusted according to the pressure difference between the inlet and outlet of the dust collector.At the same time,a three-stage filter and a refrigerated dryer are installed in the compressed air system to ensure that the air source is dry and free of oil and water,preventing oil and water from adhering to the filter bag and forming a paste bag.Regularly inspect core indicators such as flue gas temperature,dust collector pressure difference,and ash cleaning pressure on a daily basis.Offline check the filter bag for wear,brittleness,and damage every week.Clean up the accumulated ash in the flue and ash hopper in a timely manner to ensure that the ash hopper material level is always more than 30cm below the bottom of the filter bag;Before stopping the machine,blow off the dust on the surface of the filter bag.Wait until the internal temperature drops below 80℃before turning off the fan.In case of sudden situations such as overheating or condensation,immediately activate emergency measures such as cold air and heat tracing to prevent the fault from expanding.

GB/T 7714:
LI X,WANG Y,ZHANG H.Protection Strategies for Fabric Filter Bags in High-Temperature Flue Gas Treatment:A Comprehensive Review[J].Journal of Environmental Chemical Engineering,2021,9(6):106589.

MLA 9th:

Li,Xiao,et al."Protection Strategies for Fabric Filter Bags in High-Temperature Flue Gas Treatment:A Comprehensive Review."Journal of Environmental Chemical Engineering,vol.9,no.6,2021,p.106589.

APA 7th:

Li,X.,Wang,Y.,&Zhang,H.(2021).Protection strategies for fabric filter bags in high-temperature flue gas treatment:A comprehensive review.Journal of Environmental Chemical Engineering,9(6),106589.