Pulse-Jet Bag Filter Element

Function

Effective bag filter operation controls ambient dust levels at the batching plant to comply with occupational exposure limits and site environmental permit conditions — typically targeting outlet concentrations below 10 mg/Nm³. Blocked or torn filter elements reduce extraction fan flow, allowing dust to escape from mixer inlet openings, skip hopper lips, and conveyor transfer hoods — creating a workplace health hazard, abrasive contamination of nearby instruments and drives, and reduced visibility on the batching platform.

Construction & quality

Elements are cylindrical polyester needle-felt or spun-bond polyester bags, 550–600 g/m², 130–160 mm OD, supported internally by a welded galvanised steel cage to prevent inward collapse under suction. The outer surface is coated with a sintered PTFE membrane for improved surface filtration, lower operating differential pressure, and extended cleaning intervals. Seams are ultrasonically welded or heat-sealed to a minimum 15% peel-strength margin above burst pressure. Each bag is 100% individual air-tested for seal integrity before dispatch. Snap-ring tops are sized to the tube-sheet hole diameter in the housing.

When to replace

• Differential pressure across the filter housing consistently above design maximum (typically >2 kPa)
• Visible dust in the clean-air plenum chamber or at the outlet stack on inspection
• Reduced airflow measured at mixer or transfer point extraction hoods
• Bag surface tears, seam failures, or cage corrosion found on scheduled inspection access
• Pulse-jet cleaning cycle frequency automatically increasing without differential pressure recovery