Selection basis and maintenance details of boiler bag filter

The bag filter of boiler is a common equipment in boiler and industrial production Its function is to remove the particle smoke and dust from the boiler fuel and combustion exhaust gas, so as to greatly reduce the amount of smoke and dust discharged into the atmosphere, which is an important environmental protection equipment to improve environmental pollution and air quality Dust removal principle of bag type dust remover of boiler: This equipment is to enter the dust hopper of each unit from the guide pipe, under the guidance of the guide system of the ash hopper, the large particle dust will be separated and directly fall into the ash hopper, the rest dust will enter the filtering area of the middle box with the air flow, and the filtered clean gas will be discharged through the filter bag through the upper box, lifting valve and exhaust pipe As the filtration proceeds, when the dust on the surface of the filter bag reaches the corresponding amount, the dust removal control device closes the lifting valve according to the set procedure, opens the electromagnetic pulse valve for blowing, shakes off the dust on the filter bag, falls into the ash hopper and is discharged through the dust discharge valve, so as to achieve the purpose of dust removal and purification The operation quality of the bag type dust removal equipment of the boiler not only directly affects the reliable operation of the dust removal system, but also relates to the normal operation of the production system, the environmental health of the workshop area and surrounding residents, the abrasion and longevity of the fan blades, as well as the recovery and utilization of the economically valuable materials Therefore, the correct planning, selection and use of dust collectors When selecting the dust remover, one-time investment and operation cost shall be fully considered, such as dust removal power, pressure loss, reliability, one-time investment, floor area, repair management and other elements The dust remover shall be selected according to the physical and chemical properties, characteristics and production process requirements of the dust The following is the basis for the selection of boiler dust remover summarized by Huiyang Xiaobian: 1 According to the nature of dust, dust properties include specific resistance, particle size, true density, ladybug, hydrophobicity and hydraulicity, flammability, blasting, etc The ESP should not be selected for the dust with too large or too small specific resistance, and the bag filter is not affected by the specific resistance of the dust; the concentration and particle size of the dust have obvious influence on the power of the ESP, but not on the bag filter; when the dust concentration of the gas is high, the pre dedusting equipment should be set in front of the ESP; The type, cleaning method and filtering wind speed of bag type dust remover depend on the nature of dust (particle size and ladybug property); wet type dust remover is not suitable for cleaning hydrophobic and hydraulic dust; the true density of dust has obvious influence on gravity dust remover, inertia dust remover and cyclone dust remover; As for the new dust with large adhesiveness, it is easy to cause the working surface of the dust remover to be caked or blocked, so it is not suitable to use the dry method for dust removal; when the dust purification meets with water and can produce combustible or explosive mixture, it is not allowed to use the wet type dust remover 2 According to the requirements of dedusting power, the selected dedusting equipment meets the requirements of emission specifications Different dedusting equipment has different dedusting power As for the dust removal system with unstable or unstable operation condition, it is necessary to pay attention to the influence of the change of flue gas treatment capacity on the dust removal power During normal operation, the order of power bump of the precipitator is: bag type precipitator, electric precipitator and Venturi precipitator, water film cyclone, cyclone, inertia precipitator and gravity precipitator 3 Air volume, temperature, composition, humidity and other factors shall be taken into consideration when selecting bag filter according to gas properties Electrostatic precipitator is suitable for flue gas purification with large air volume and temperature < 400 ℃; bag filter is suitable for flue gas purification with temperature < 260 ℃, which is not limited by the amount of flue gas When the temperature is ≥ 260 ℃, the flue gas should be cooled and cooled before using bag filter; bag filter is not suitable for flue gas purification with high humidity and oil; Flammable and explosive gas purification (such as gas) is suitable for wet deduster; the processing air volume of cyclone deduster is limited, when the air volume is large, multiple dedusters can be selected in parallel; when it is necessary to dedust and purify harmful gas together, spray tower and cyclone water film deduster can be selected Maintenance details of each part of the bag filter of the boiler: 1 Filter bag: check the clean air chamber and filter bag regularly to see if there is dust, water vapor or rust spots Once the above situation occurs, it means that the filter bag is damaged or the operating conditions are not correct 2 Electric control element: like other parts of dust remover, the electric control element does not need regular service However, we suggest to use the regular clearance period to check it The inspection of integral components such as solenoid valve can be carried out in the way of replacement, and the damaged components are recommended to be sent to the manufacturer for repair 3 Electromagnetic pulse valve: the fault of diaphragm valve is divided into start fault and close fault The opening fault may be caused by continuous excitation, accumulation of internal impurities, excessive wear of the diaphragm, or worn piston blocking the shell tube The opening fault of diaphragm valve can be detected by excessive consumption of compressed air, pressure drop of compressed air pipe or continuous leakage sound of valve After finding the cause of the problem, first remove the system pressure, then remove the valve cover, and check whether there are sundries at the seal of the diaphragm, whether the diaphragm is damaged, and whether the spring is invalid Do not attempt to disassemble the diaphragm valve without removing the system pressure Turn off fault detection can be checked by over light impulse sound when the solenoid valve is energized If the solenoid valve does not act or the solenoid component is divided into actions but the valve does not act, it indicates that there is a problem with the solenoid operated valve or controller, which needs to be replaced The inspection of the solenoid valve includes whether all connections are tight when the power supply is disconnected and whether the operation of the valve is normal 4 Condition of dust remover: the water vapor phenomenon in the dust remover room, such as small puddles or rust spots, is caused by condensation of water vapor or hot flue gas, or because the closing time of the filter room is too long and the internal flue gas temperature is too high during the closing time, add insulation or correct operation procedures to eliminate this problem The above is the basis for the selection of bag filter and the maintenance details of each part, which is compiled by Huiyang small I hope it can help you.