Among other tasks, a stenter frame is used to fix and dry finished textiles. The textile web passes through several sections of the stenter frame through which hot air flows.

Prior to releasing the energy-rich exhaust air into the open atmosphere, a heat recovery unit recovers part of the exhaust air heat and preheats the supply air to the stenter frame. Dust and water vapour as well as oils and other aerosols are emitted during drying of the textile webs. This can be limited by washing the textiles; nevertheless, a stenter frame cannot be operated without emissions. For reasons of environmental protection, the cleaning of the exhaust air is imperative.

The air washers commonly used in the textile industry have poor filter performance, however. This causes clogging again and again which interrupts the operation. An electrostatic precipitator fitted downstream can improve filter performance. These electrical filters are highly susceptible to disturbances, however, and involve high operating costs. Sometimes there are short circuits.

As an alternative, the Swabian company Rentschler Reven from Sersheim recommends a special X-Cyclone separator. It is additionally equipped with a water spraying device which wets all surfaces with a water film. The undesirable particles are washed out of the exhaust air to a high degree. Subsequently, they are ejected through rapid deflections in the X-Cyclone separator. The high turbulences improve the degree of separation on the one hand and extremely increase the particle transfer between the exhaust air and the washing water on the other hand. This provides for an improved cleaning performance. The combined filter works on a purely mechanical basis and practically cleans itself during operation.

An example:

The textile finisher Van Clewe in North Rhine-Westphalia recently renewed the air cleaning system on a Monforts stenter frame. The company adopted the system configuration recommended by Rentschler Reven and dispensed with the electrostatic precipitator. The X-Cyclone separator replaces the initially provided electrostatic precipitator as well as the droplet separator. The new concept allows Van Clewe to save maintenance and energy costs. In addition to this, it provides for exhaust parameters that comply with legal workplace exposure limits. Company spokesman Ansgar van Clewe confirmed: “The new air washer unit works very well. It is free of clogging, which normally occurred after just a few shifts.”