In the process of using the bag filter, due to various factors, such as poor dust removal, low dust removal efficiency, and excessive emission concentration, the following is carried out by Zhangzhou Xuyang Weiye Environmental Protection Equipment Co., Ltd. based on years of technical experience in the bag dust collection field. A summary of several common problems, analysis of causes and detailed analysis of solutions.
1. The resistance increases beyond the normal value and the resistance cannot be reduced after the cleaning operation.
Causes:
(1) Produce paste bag phenomenon
(2) The dust removal device is in failure and there is no dust removal effect.
(3) Poor cleaning effect.
(4) The filtering speed is too high
Treatment method:
(1) Dispose of the bag filter bag, or spray or cover an ultra-thin PTFE microporous membrane on the filter bag and the dust contact surface, or spray the surface of the filter bag with a special treatment powder to form a very thin filter cake on the surface. The porosity is relatively uniform and small; special techniques such as calendering or sintering can be applied to the surface of the filter cloth to achieve the same purpose. Oil-proof, anti-static, and waterproof filter cloths can also be used. Insulation measures are adopted to avoid condensation and cause the paste. bag.
(2) Check the dust removal device and handle the fault.
(3) Reduce the cleaning cycle and increase the injection time; increase the injection pressure.
(4) Find the cause, perform the treatment, check the air leakage, and perform plugging.
2. Others are normal, but the emission concentration is excessive.
Causes:
(1) Damage to filter bag of dust collector.
(2) The filtering speed is too high, causing dust leakage.
(3) The blowing time is too long or the cleaning is frequent, resulting in the destruction of the initial dust layer.
(4) Dust removal is too strong, causing secondary dust.
(5) The structural design of some air bags is unreasonable, and the air leakage occurred during the installation of the pulse valve.
Treatment method:
(1) Maintenance and replacement of filter bags. The outer diameter of the bag cage and the inner diameter of the filter bag must be kept at a certain distance, and the distance between them will increase the wear of the filter bag, so the spacing should be reduced.
(2) Find the cause, perform processing, and reduce the filtration speed.
(3) Reduce the blowing time and increase the cleaning cycle.
(4) Reduce dust removal.
(5) Make reasonable modifications to prevent air leakage.
(6) Properly increase the height of the box and the height of the hopper to ensure that the hopper’s tilt angle is not less than 60 degrees. For vibrators with high humidity and dust, install a vibrator at the hopper of the dust collector. Anti-ash ash, especially suitable for wet weather in the south.
3, the flue gas temperature is too short, too high, too low or filter bag combustion.
Causes:
(1) The temperature of the flue gas is high because the actual evaporation of the boiler exceeds the rated evaporation or the combustion is adjusted improperly or the heated area is ash slagging.
(2) The low temperature of the flue gas may be due to many reasons such as the leakage of the boiler tail, combustion adjustment, and heating surface transformation, resulting in a low exhaust temperature of the furnace.
(3) There may be flammable particles.
Treatment method:
(1) Using an off-line protection system, when the temperature of the flue gas is too high or the back of the boiler is re-ignited, the spray cooling system starts, and the emergency spray water is cooled to avoid burning the filter bag, contacting the boiler, and performing combustion adjustment.
(2) Put the air preheater on the bypass flue; reduce the amount of tail ash blowing; use the upper platoon milling system; open the hot air recirculation door of the air blower under low load conditions; increase the cold air inlet temperature; turn on low during normal operation; The hot air recirculation of the blower on the flue gas side and the increase of the bottom load, etc., if still low, will require further improvements in the boiler.
4, flower board dust.
Causes: Damage to the filter bag, poor sealing between the filter bag and the short tube and the flower plate, etc., can lead to different degrees of dust accumulation on the board.
Treatment method: Inspect the filter bag and strengthen the seal between the filter bag connection tube and the flower plate.
5, often broken bag site.
Causes:
(1) If the distance between the filter bags is too close, not only the collision between the cloth bag, the cloth bag and the wall board will be abraded, but also the air flow rising speed of the box will be affected, resulting in the local filter load of the filter bag being too high and the cleaning dust intensity being insufficient. The cleaning is frequent.
(2) Temperature is very sensitive, the flue gas temperature exceeds the allowable limit, in a short time will cause damage to the filter material, the filter material strength failure filter material is sensitive to oxygen at high temperature, when the flue gas oxygen content exceeds the critical value, Defects in the thermal oxidation and decomposition of the filter during a certain period of time.
(3) High jet pressure will cause severe damage to the filter media and drastically reduce the service life of the filter media.
(4) The air flow is unevenly distributed.
Treatment method:
(1) Adjust the filter bag spacing. According to experience, the filter bag edge spacing is at least the radius of the filter bag itself.
(2) Use high-temperature, high-strength filter media. In the normal operation of the boiler, the oxygen content of the flue gas is generally lower than the critical value of the filter material. Therefore, during the design, the flue gas after the bag filter is used as a gas source for cleaning gas Beijing Opera, avoiding inhaling a large amount of fresh air.
(3) The blowing air pressure should not exceed 0.20 MPa and it is appropriate to keep the cleaning effect low.
(4) Find the cause and carry out the transformation.