Key Benefits

  • Low operational costs
  • Longer bag life
  • Reduced CAPEX

Bag filter system for upfront savings and reliable emission reduction

The FLSmidth DuoClean™ baghouse filter system helps you meet the strictest dust emission requirements, while reducing upfront costs. Based on an industry-proven design and technology, they feature an innovative octagonal shape and a compact, modular design.

Our extensive R&D work has resulted in an effective, innovative fabric filter solution, ideal for medium to large gas flows. We have developed two types of DuoClean bag filters: the DuoClean DC2 and DuoClean DC8. Both feature an octagonal shape, giving them a compact, modular bag filter design. This unique design fast-tracks manufacturing and construction time, minimising delivery time and costs.


Already installed at more than 50 plants worldwide, the DuoClean filter has a proven design and technology concept. In creating the two new baghouse filters, FLSmidth has further developed the most important DuoClean characteristics, including the cleaning system, gas distribution capabilities and the long filter bag technology.


Large-capacity baghouse filter

The DuoClean DC2 fabric filter consists of multiple octagonal modules that are connected as one, compact bag filter, with a small footprint. The DuoClean DC2 handles gas flows from 150,000 to 1,900,000 Am3/h, making it ideal for large mill and process applications.

It is suitable for bag filter lengths of 6-10 metres and includes the unique gas distribution screens, ensuring an even distribution of gas. The DuoClean DC2 comes with top access or weather enclosure design.

Our goal in developing the DuoClean DC2 bag filter has been to optimise the entire supply chain. We reduce costs and minimise environmental impact by carefully planning and managing the entire process – from design, production and manufacturing to packing, shipping, installation and commissioning


For smaller baghouse filter needs

The DuoClean DC8 bag filter is a one-compartment fabric filter in an octagonal shape that is suitable for gas capacities from 45,000 up to 150,000 Am3/h. The bags can be from six to 10 metres long. It is ideal for, but not limited to, smaller mill and process applications where the capacity of a bag filter with multiple compartments is too large.


The DuoClean DC8 baghouse filter offers excellent pre-separation ability and gas distribution with a low uniform velocity over the entire bag filtration area.


Different types of filter tops are available for the DuoClean DC8 filter: top access, weather enclosure (for weather protection) or a walk-in plenum.

Cost-effective construction

The design of the compact filter ensures that the filter modules are optimised for transportation. When arriving at site, the filter modules are typically assembled at a dedicated area close to the plant. This ensures a high degree of pre-assembly and means that construction can be done in a safe environment.

DuoClean fabric filter construction site

Optimised transportation

The steel parts for baghouse filters are often fabricated far away from a plant, requiring sea-based transportation.


The DuoClean filters’ octagonal shape casing and the width of the eight side panels and hole-plate elements fit into a standard shipping container. The containers are packed with a focus on utilising the entire space, reducing the number of containers required and minimising transportation costs.

Increase baghouse life with highly effective bag filter solutions

Low operational costs
FLSmidth’s DuoClean filters ensure an outstanding performance at a low operational cost. Thanks to the unique gas distribution and pre-separation of dust, the pulse jet cleaning system operates with a minimal number of cleaning cycles, resulting in low compressed air consumption, less wear of the bags and an increased bag lifetime.
Longer bag life
The dual-flow gas approach optimises dust and gas distribution, resulting in longer bag life and greater overall efficiency.
Reduced CAPEX
The long filter bag technology reduces filter footprint and CAPEX. The compact, modular design makes it easy to manufacture, transport and construct onsite.

Innovative octagonal shape in a compact, modular filter design

The DuoClean baghouse filter system is based on a dual-flow gas approach, where the gas enters from the bottom and the sides of the bags. This ensures a low, uniform velocity over the entire bag filtration area, meaning you can use longer bags, which reduces the filter footprint.

To ensure even distribution of gas to the hoppers and on the bags, individually designed gas distribution screens are used for each filter application.

The DuoClean system features a low-pressure fabric filter cleaning system, where the cleaning pressure is no greater than 2.0 bar. We have conducted extensive research and testing to ensure efficient cleaning and reduced stress on the long bag filters. This means that the traditional high-pressure compressor (6-7 bar) can be replaced with a root blower, saving investment and operational costs.


Self-reinforcing shape and cost-effective construction

The new modular design and octagonal shape of the bag filter enables the use of simple reinforcement profiles and reduces the number of different components.


Eight identical panels are assembled in an octagon. This near-round shape significantly reduces stress and strain on the filter fabric.


The optimised casing and hoppers reduce the weight and complexity of steel construction, making the fabrication and workshop assembly cost-effective.


Extensive fabric filter R&D

We have invested substantial R&D efforts towards achieving optimal control of gas distribution and the ideal dual-flow split. To develop new filter types, FLSmidth uses computational fluid dynamics (CFD). For the new DuoClean DC2 and DC8 filters, the CFD results demonstrate a well-distributed gas flow with significant dust being pre-separated to the hopper. This ensures uniform gas speed to the bags, reduces compressed air usage and increases the lifetime of the bags, leading to lower OPEX.


Easy assembly and quality assurance

Filter components are typically assembled at a dedicated area close to the plant, and construction is completed on-site while the filter is installed in its final position with a high degree of pre-assembly. This reduces the need for scaffolding and crane capacity and means that construction can be done quickly, in a safe environment, and at reduced cost.


In addition, as the prefabricated parts are standardised, the risk of errors is reduced, and quality assurance is trouble-free.

These 8 steps illustrate a DuoClean DC2 filter taking shape. Construction and installation can be as quick as just four weeks. The components arrive on-site in containers. You only need a crane for the final moving of the pre-installed components to the final filter location; otherwise all construction is done at ground level.

We placed our order with FLSmidth after carefully considering the advantages of having a small footprint, less total structure weight, and the single compartment solution. Because of the modular design, where all the side walls are completely identical, transportation to our plant is straightforward and the octagonal shape provides very good stress and strain advantages.

Europe Technical PurchaserMr. Benoit Bolly, Cameuse Coordination Center, Belgium

New fabric filter ensures low emissions and high efficiency at Duna-Dráva Cement Ltd.

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