Reverse air filter bags
made of needle felt and glass fibre fabric
Reverse air filter bags are suspended from the filter housing at the closed top end, and fastened to the head plate at their open bottom end. During filtration, dust-laden gas enters the filter bag from below. As it travels upwards the gas also flows towards the outside, while dust collects on the inside of the filter bag.
To remove the filter cake, the compartment to be cleaned is separated out from the filtration process (taken off-line). A backwash fan then creates a counterflow, causing the filter bag to partially collapse. To prevent total collapse, support rings are sewn along the edge of the filter bag at set intervals. After cleaning, the compartment is brought back into the filtration process (taken on-line).
- Large filter bag dimensions (diameter up to 300 mm, length up to 12,000 mm)
- Quasi-continuous operation
- For high exhaust gas volumes
- Basis weight is usually between 400 – 450 g/m²