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).

Your benefits at a glance

  • 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

Depending on the temperature, filter media from the entire product portfolio may be used.

8 reasons to use BWF Envirotec filter bags
Put us to the test


Over 50 years' experience in industrial filtration and filter bag production.

Product diversity

2,100 Standard products and 17,000 worldwide applications available at the click of a mouse.

On-site worldwide

15 Production and sales locations and a global network of partners means that we always speak our customers' language.

Market leader

Our industrial filters benefit from continual research and development: All finishes are applied in our R&D competence centre.

Transparent process chain

At BWF Envirotec, all products are manufactured in-house in a continuous process chain: Filter medium - filter bag - service - everything from a single source and company.

All-round service

Whether it's assembly, commissioning, maintenance, repair or optimisation - we service filter bags for a wide range of reasons, but with only one goal in mind: Your total satisfaction.

Complete support

Professional support beginning with the first consultation - our sales department and application technology stay by your side in word and deed throughout the entire process.

On site trainings

The BWF Envirotec Training Academy offers customers basic and practical seminars either on our premises, or directly on site.

Product lines from BWF Envirotec
The right filter for every conceivable dedusting application

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