Boiler dust bag filter workshop polishing and polishing dust removal equipment

Boiler dust bag filter workshop polishing and polishing dust removal equipment

The pressure difference of the filter bag is a core indicator reflecting the operating status of a single machine bag filter. During normal operation, the pressure difference is usually stable at800-1500PaIf the pressure difference continues to exceed1500PaThis indicates that the dust on the surface of the filter bag cannot be effectively removed, and a dense dust layer has formed, which will seriously hinder the airflow. This will not only reduce the processing air volume and dust removal efficiency of the single machine bag filter, but also keep the fan in a high load operation state for a long time, increasing electricity consumption. At the same time, the filter bag is prone to damage under high pressure difference, shortening its service life. Therefore, it is necessary to quickly identify the cause of the high pressure difference and take effective solutions.

A common reason is the condensation of dust containing gas, which leads to the sticking of filter bags, especially in high humidity or high temperature fluctuation scenarios. When the temperature of the dusty gas approaches or falls below the dew point temperature, water vapor in the gas will precipitate water droplets, mix with the dust to form a viscous mud like substance, adhere to the surface of the filter bag to form a hard structure, and cannot be peeled off by ordinary dust cleaning methods. The main factors causing condensation include: the single machine bag filter is not equipped with insulation devices, and the pipes and boxes dissipate heat too quickly in low temperature environments, causing the gas temperature to drop below the dew point; Fluctuations in production processes lead to sudden drops in the temperature of dusty gases, such as frequent equipment starts and stops in intermittent production; The excessive suction force of the fan causes a large amount of cold air to be sucked in from the gaps of the equipment, reducing the gas temperature. To solve this problem, we need to “anti-condensation”and“Dust removal”Starting from two aspects: firstly, install insulation layers (such as rock wool, glass wool) on the box and pipes of the single machine bag filter, with the thickness determined according to the ambient temperature, usually50-100mmAt the same time, seal the gaps of the equipment to reduce the infiltration of cold air; Secondly, adjust the process parameters to ensure that the temperature of the dusty gas entering the equipment is higher than the dew point temperature15℃above; If bag sticking has occurred, the filter bag should be removed after stopping the machine, and blown back with compressed air or rinsed with clean water (only applicable to water-resistant filter media). In severe cases, the filter bag should be replaced directly. The single machine bag filter of a certain feed factory once had its filter bag stuck due to lack of insulation in winter, causing the pressure difference to rise2000PaAfter installing insulation layer and replacing filter bag, the pressure difference was restored to1200PaRestore normal operation.

The second common reason is improper parameter settings or core component failures in the dust cleaning system, resulting in poor dust cleaning effectiveness. The dust cleaning system is the key to removing dust from filter bags, and any abnormality in any link will affect the dust cleaning efficiency. Improper parameter settings mainly include: excessively long pulse blowing time interval, and filter bag dust accumulation exceeding the critical value for cleaning; The spraying width is too short, and the compressed air fails to fully impact the filter bag; The compressed air pressure is too low (below)0.4MPa）Unable to generate sufficient impact force to peel off the dust layer. The main faults of core components include: damage or aging of the electromagnetic pulse valve diaphragm, resulting in weak blowing or air leakage, and inability to maintain the pressure of the airbag; Blockage of the blowing pipe or misalignment of the blowing hole prevents compressed air from accurately acting on the filter bag; The controller program is out of order and cannot trigger the dust cleaning action in the preset sequence. The solution needs to be handled on a case by case basis: if it is a parameter issue, the data needs to be monitored through a differential pressure sensor, and the injection cycle needs to be gradually adjusted (shortened to20-40Seconds), spray width (extended to0.15-0.2Seconds) and compressed air pressure (increased to0.5-0.6MPa）Until the pressure difference stabilizes within the normal range; If it is a component failure, it needs to be checked one by one: check the pulse valve diaphragm and replace it immediately if any damage is found; Dismantle the spray pipe to clean the internal dust accumulation and correct the position of the spray hole; Restart or reprogram the controller, and replace the control module if necessary. The single machine bag filter in a certain mechanical processing plant is unable to clean dust due to the aging of the pulse valve membrane, and the pressure difference has increased1800PaAfter replacing all the membranes, the dust removal is improved and the pressure difference is reduced1000Pa.

The third common reason is that the selection of filter media does not match the characteristics of dust, resulting in clogged filter bags. The filter material is the core filtering component of a single machine bag filter. If the material, structure, and dust characteristics do not match, it is prone to clogging. For example, when dealing with dust with high viscosity and small particle size, ordinary needle punched felt filter material without film covering is used, and the dust will penetrate deep into the interior of the filter material and cannot be peeled off; When dealing with high-temperature dust, normal temperature polyester filter material is used. The shrinkage of the filter material due to heat causes the pore size to decrease, and the dust clogs the pores; When dealing with corrosive dust, non corrosion-resistant filter media is used. The structure of the filter media is damaged after corrosion, and the dust adhesion is severe. The core of solving this problem is to replace the adapted filter material: for viscous dust, selectPTFECoated filter material, with a smooth surface coating that can prevent dust from penetrating deeply and has good peelability; For high-temperature dust, choose aramid according to the temperature range（120-260℃）Or fiberglass (>260℃）Filter material; For corrosive dust, selectPTFEOr Flumes filter material, with excellent acid and alkali resistance. When a chemical enterprise processes sulfur-containing dust, it initially uses ordinary polyester filter bags,3 Due to corrosion blockage, the pressure difference was too high within a month, and it was replacedPTFEAfter laminating the filter material, not only is the pressure difference stable, but also1300PaThe lifespan of the filter bag has also been extended to2 Years or more.

Boiler dust bag filter workshop polishing and polishing dust removal equipment