Key Benefits

  • Increase fabric filter capacity
  • Minimise environmental footprint
  • Increase filter reliability

Extensive R&D tests and field installations

Proven results

We developed OptiSize™ in our R&D center in Denmark and our facility in the United States. We offer a new concept of filter upgrade that can significantly improve your fabric filter operation.


OptiSize filter bag concept is based on the switch from the traditional circular bag shape to a square shape with rounded corners, increasing the perimeter of the filter bag and filtration surface at equal bag length.  The result is an increase of filtration area up to 15 percent within the same filter casing volume compared to a “traditional” round bag.  OptiSize is available in all type of felts and fiberglass media to replace the five inch and six inch filter bags.

OptiSize increases filtration area and save energy

Lower CAPEX:

You can install OptiSize™ in a new filter or upgrade an existing one to increase capacity. In case of upgrade you can reuse the filter casing, clean gas plenum, cleaning system, control system, dust extraction system and other auxiliaries on the baghouse filter; all you need is to replace the tubesheet and install new bags and cages. This will lower your investment cost significantly compared to extending your existing baghouse. A comparison is given in the chart to the right.

Lower OPEX:

The increase of filtering area at equal production capacity contributes to lower differential pressure (dP) across the filter bags which results in lower power consumption on the system fan. Furthermore, the reduction of dP has a positive effect on the lifetime of the bags with less internal bag and cages wear during cleaning cycles.


We have noted performance improvements in the mill’s inlet pressure, as a result of the new OptiSize bags increased filtration area.

Irfan Butt, Maintenance Manager of the plant

Stories from FLSmidth