Paşa Tekstil Invested in Exhaust Air Filtration System of KMA
Textile finishing encompasses important processes at the interface between textile production and ready-to-wear clothing. A wide range of processes are used to give the textiles the required properties, such as flame retardancy or crease resistance. This requires the textiles to be heated up to 200°C with the aid of a stenter frame. Energy consumption is correspondingly high. At the same time, textile finishing generates exhaust air that is heavily contaminated with pollutants. To protect residents and the environment, increasingly strict regulations have been imposed in recent years for the associated emissions. The limit values to be complied vary depending on the location of the company.
For example, they can be a maximum of 10 mg/m³ for oil aerosols in densely populated areas or 20 mg/m³ outside cities. Textile companies are therefore required to clean the exhaust air from textile finishing. Most of the technologies offered for this purpose disregard one crucial point. The exhaust air not only carries impurities and pollutants, but also valuable heat energy. Heat that was previously generated at high cost through the use of natural gas, electricity or steam. It should therefore be the objective of innovative textile companies to combine two goals: Firstly, to effectively clean the exhaust air of impurities and pollutants in order to be able to demonstrate compliance with the specified limit values.
On the other hand, to recover the energy contained in the exhaust air and make it usable for the manufacturing processes, thus reducing energy costs and making an additional contribution to environmental protection by saving CO2 emissions. The following example of the Pasa Textile company impressively shows how this can be successfully achieved.
Ecology in harmony with economy
Pasa, a traditional Turkish textile company with its headquarters in Istanbul, exports innovative, high-quality embroidered curtains and garments to more than 40 countries around the globe. It is also one of the leading manufacturers of home textiles and garments in the domestic Turkish market. For the production site in Çorlu, the company dealt intensively with the previously explained challenge and decided on an Ultravent® exhaust air filtration system with integrated heat recovery from the German manufacturer KMA Umwelttechnik.
The exhaust air from the stenter, with a volume of 20,000 m³/h and an average exhaust air temperature of approx. 129°C, is first routed via a two-stage heat recovery system. In an air-to-air cross-flow heat exchanger, the hot exhaust air is crossed with a flow of fresh air. The fine fins of the heat exchanger allow the heat energy to be transferred optimally, so that the supply air is heated from an ambient temperature of approx. 28°C to approx. 115°C. The fresh air is returned directly to the stenter via a pipe – only a few degrees below the required operating temperature.
The exhaust air then passes through an air-water fin heat exchanger. In this, further heat from the exhaust air is transferred to the water circulating in pipes. The water, which enters at approx. 22°C, is heated to an initial temperature of up to 74°C in this process. The heated water is used in the dyeing plant to color the textiles.
A desirable side effect of heat recovery is that previously gaseous components in the exhaust air condense out. The exhaust air, cooled in this way to approx. 60°C, is passed through a two-stage electrostatic filter in the next step. Here, the oil aerosols contained in the exhaust air are separated. An electric field with high voltage is generated by the electrodes arranged in the air flow and the particles contained in the exhaust air are charged. Like a magnet, the particles thus charged are deflected to the metal plates arranged in the downstream collector zone and held there. This highly effective exhaust air purification causes hardly any air resistance and is extremely energy-efficient. The cleaned exhaust air is finally discharged into the open air via the chimney. By means of the integrated cleaning system, the separated pollutants are washed off the filter and the heat exchangers and disposed of with the waste water.
Not only does the Pasa Textile company effectively remove impurities and pollutants from the exhaust air with this system, it also achieves an impressive energy recovery of 398 kW per hour. With 141 kW of the recovered energy, the fresh air is heated and fed into the stenter to sustainably reduce the gas consumption of the stenter. The remaining 257 kW recovered is used to heat 2.2 m³/h of water without the addition of electricity or gas, which also contributes to reducing energy consumption. Calculated over the year, the textile company thus saves 1,691,500 kWh. This corresponds to an annual cost saving of about 1,206,209 TL (at 0.7131 TL/kWh). Thus, the plant pays for itself within a short period of time. It thus not only fulfills the official requirements for environmental protection. It also makes a sustainable contribution to reducing the operating costs of the production processes.
Equally impressive is the view of the CO2 footprint: Thanks to the heat recovery system, the Pasa Textile company reduces its own annual CO2 emissions by around 532.51 tons. It is thus also demonstrating a sense of responsibility towards future generations.
Best Practice with an exemplary function
Many textile companies are faced with the challenge of reliably removing impurities and pollutants from the exhaust air from textile finishing. At the same time, the constantly rising costs of energy require a rethink in the handling of the waste heat contained in the exhaust air. Pasa Tekstil is committed to meeting this challenge and acting with foresight. The Ultravent® exhaust air filtration system from KMA Umwelttechnik is an extremely innovative solution in terms of both high-grade exhaust air purification and highly efficient heat recovery. This combination not only ensures more environmental protection, but also lower operating costs for the company.
