Heat recovery from wasteair

Exhaust air from paper production (e.g., from the drying sections) contains large amounts of moisture and thus a considerable amount of thermal energy.

The exhaust air can be collected and passed through a FERCHER Energy Spray Tunnel. There, the exhaust air is sprayed with a mist of fine water droplets, cooled, and washed out.

The spray water runs in a circuit and only needs to be filled once.

Special dirty water nozzles are used in the FERCHER spray tunnel, which reliably spray even dirty water into a fine droplet mist.

The heat from the now heated spray water can be transferred to clean process water using a FERCHER wastewater heat exchanger. The thermal energy obtained can be used in a variety of ways, e.g. for boiler feedwater preheating, waste paper processing, hall heating, etc.

Wasteair cleaning

The fine droplet spray in the spray tunnel washes macroscopic particles such as dust or lint out of the exhaust air and into the spray water. These solids can then be easily removed via the overflow in the spray water tank.

The exact degree of purification depends on the composition of the exhaust air. In the vast majority of cases, virtually 100% of the solids are washed out of the exhaust air.

Positive side effect: water extraction

When operating with sufficiently humid exhaust air, water condenses as the exhaust air cools, resulting in excess water in the spray water. This recovered water can either be used in the process or disposed of as wastewater.

A droplet separator at the end of the spray tunnel ensures that no water is wasted. The separated water flows out along with the spray water in the spray tunnel.