Due to rapidly rising energy costs or even supply bottlenecks, energy consumption is more in focus today than ever before. In order to increase the energy efficiency of production plants in textile finishing, heat recovery systems should additionally be used. These use the exhaust air heat of the production plants to heat fresh air or water. Due to legal requirements, such as the German TA-Luft, it is necessary to clean the exhaust air of the drying lines. At Brückner Textile Technologies GmbH & Co. KG, Leonberg/Germany, heat recovery and exhaust air purification are combined in one plant.
The first line stage is usually an Eco-Heat heat-recovery system air/air. Here, by means of plate or tube heat exchangers, the exhaust air heat is indirectly transferred to cold fresh air, which is then fed back into the drying process. This increases the drying capacity and reduces energy consumption. Of course, ambient air can also be heated with this system, especially in colder countries, thus relieving the buildings’ heating system.
An Eco-Heat system air/water is often used as a second stage. The exhaust air heat is transferred to water through heat exchangers. The heated water is then used in other textile processes or is also used to heat buildings, thus reducing energy requirements elsewhere. Through heat-recovery, the exhaust air from a drying line, which is contaminated with spinning oils, kerosene, finishes or chemicals, is already cooled down considerably, causing the pollutant particles to condense on the heat exchangers and be separated out. Over time, however, deposits form on the heat exchangers. Integrated steam cleaning, while not 100% clean, keeps the heat exchangers operational for an extended period of time.
If in addition to the heat-recovery an exhaust air purification is of interest, Brückner offers with its Eco-Air products a modular system for the compliance with existing exhaust air regulations, e.g. the German TA-Luft. Here the second or third system stage after the Eco-Heat heat-recovery can be an Eco-Air exhaust air scrubber which cools down the exhaust air further and binds oil-containing pollutants in its closed water circuit.
If this is still not sufficient for some special processes, an additional bio-filter can be installed downstream. This is a simple and cost-effective method of cleaning exhaust air containing odorous substances and VOCs. Micro-organisms on carrier material in special biofilter containers convert organic contaminants into carbon dioxide with the aid of oxygen. In addition, organic molecule chains can be broken down in a UV light reactor by intensive UV light irradiation of the exhaust air, and oxygen can be converted into active ozone.