Preventive maintenance instructions for dust collectors bag filter

  Inspection/Maintenance Plan: The preventive maintenance checklist for the dust removal room should include regular inspections, including daily, weekly, monthly, semi-annual and annual inspections of specific items.

  Pressure drop: Pressure drop (or pressure difference) is the level of electrostatic resistance encountered when operating a positive or negative pressure bag filter. It is usually measured in water column inches (inches) throughout the filter bag. The pressure drop can indicate the amount of dust collected on the filter media; if continuously monitored and recorded, the pressure drop can also indicate the condition of the bag itself. The new filter bag has the lowest pressure drop. When the bag forms a dusty cake, the pressure drop will increase accordingly.

  From the day when the new filter medium is installed, the pressure difference of the bag filter chamber is recorded every day to help diagnose possible problems (for example, increase dust emissions, reduce the ventilation air at the dust source, shorten the life of the packaging bag, etc.). After the initial seasoning or conditioning of the filter bag, the pressure drop should be relative to the cleaning cycle, and the use and style of the equipment should be stable within a stable operating range. Any deviation should trigger an investigation.

  Cleaning system: The cleaning system is a method used to remove the dust cake accumulated in the filter medium. Without an effective cleaning system, dust will continue to accumulate on the bag, resulting in increased pressure drop and reduced ventilation air at the pick-up point. The airflow speed in the duct will decrease and cause the dust in the duct to fall, thereby blocking the entire system. Pulse valve failure and loose pulse clamps can also affect the performance of the cleaning system.

  Hopper discharge: The hopper in the dust removal room is not used to store the collected products. This may cause dust to bridge or may form solid blocks that are difficult to remove. This material can fill the hopper to its inlet and block the equipment. For low-density materials, the airflow may sweep dust into the bag section, thereby damaging the filter bag and blocking the dust collector.

  Visible emissions: Any visible particulate emissions indicate that there may be a crack in the sealed or damaged filter bag. Exceeding the allowable particulate emission limit is a problem. This kind of discharge will not only cause health problems and property damage, but if this condition is not corrected quickly, the fan downstream of the collector may be damaged or become unbalanced due to wear.

  Exhaust fan: The exhaust fan accelerates the ventilation through the duct system and the filter medium of the bag filter from the pickup point, and discharges the exhaust chimney. Choose a fan to suit each application in terms of overall system size (ACFM) and pressure drop. This pressure drop is calculated by evaluating the static resistance of the dust collection chamber, all piping systems and pick-up points/hoods. If the belt of the exhaust fan is loose or worn or the impeller is unbalanced, it cannot discharge the amount of air originally designed to handle. Without adequate ventilation, the dust collection system will not operate effectively.

  Filter media: filter bags must be checked regularly. Check for leaks on the clean air side of the dust removal room. The pressure drop that is much higher than the previous pressure drop may be caused by excessive dust or clogged filter bags. If the dust cake has hardened to the bag and does not fall off easily, the most likely cause is the moisture in the dust removal room.

  Structural integrity: A comprehensive inspection should be carried out once a year, including welding, joints and flange sealing. Check the structural support members for signs of fatigue and excessive corrosion. Ensure that all fasteners are in place and firmly secured, especially on ladders and service platforms. Replace all missing bolts, clean and re-weld cross braces or gussets that may cause weld cracks. Look carefully for signs of corrosion or bending on the outer wall of the filter. Repair any holes that may have formed in the dust collector wall or hopper.

  Auxiliary equipment: These items include exhaust fans, rotary air gate valves, screw conveyors, inlet and/or outlet dampers, etc. Please follow the manufacturer's instructions.