[독일] 하수처리 플랜트의 에너지 효율 개선

독일 Versmold는 하수처리 플랜트의 압축 공기 공정에서 에너지를 효율적으로 공급하기 위한 노력으로 두 개의 tlas Copco ZS 55+ oil-free screw blowers와 variable speed drive (VSD)를 설치했다고 밝혔다. VSD 효율화의 결과로 플랜트는 10%의 에너지 절감에 성공했고 고객들에게 보다 저렴한 하수비용을 부과할 수 있게 됐다.

플랜트는 매일 300만 갤런의 하수를 처리한다. 그 중 60%가 산업폐수이며 나머지는 Vermold의 생활 하수이다. 특히, 정육 산업이 높은 비율을 차지하며 고오염지역의 다양한 비율과 높은 인산염의 양은 플랜트가 다뤄야할 과제이다. 이에 정화기술, 측정기술, 공정제어 시스템, 압축공기 기술은 빠르게 하수 오염을 제거하고 대응할 수 있다.

In an effort to supply energy-efficient compressed air to process sewage at a treatment plant in the town of Versmold, Germany, two Atlas Copco ZS 55+ oil-free screw blowers with variable speed drive (VSD) have been installed. As a result of the efficiency of the VSD, the plant has achieved energy savings of 10 percent, which means lower sewage fees for customers.

The plant cleans around 3 million gallons of sewage water every year. Sixty percent of this comprises industrial sewage, and the remainder is domestic sewage from Versmold. Specific to the plant is the high proportion of industrial customers from the meat processing industry, which generates varying rates of high polluting loads and above-average quantities of phosphate that are a challenge for the plant to handle.

Accordingly, the cleaning technology, the measuring technology, the process control system, and the compressed air technology must be able to quickly detect the pollution level of the sewage water and respond accordingly.
 
Nitrification and denitrification take place simultaneously in two aeration tanks. In the course of the aerobic degradation processes, the biological process is first supplied with oxygen via the plate aerators. During the subsequent anaerobic phase, only the tank contents are mixed together. Each of the tanks is supplied with oxygen via the blowers.

The control function is taken over in each case by the Atlas Copco screw blowers. The two machines, working together with the blowers supplied by another manufacturer, provide compressed air between 1,500 and 3,500 m³/h with a target excess pressure of 500 mbar to maximum 600 mbar. The volume flow is automatically adjusted to the exact air demand by the VSD.

[출처 = Water World / 2014년 8월 5일]