Siemens Aeration Competence Center (ACC) offers a wide portfolio of turbocompressors for aeration needs in waste water treatment. Jan Olsen, Director at ACC – Siemens, Denmark speaks to Buildotech on the aeration technology and its scope in India.
What is the aeration compressor technology?
Aeration is the process by which compressed air is forced through a liquid or substance, normally from the bottom of a tank, in order to reach a certain level of dissolved oxygen concentration.The process control is linked to the flow control of the compressor which must respond exactly and stay within small tolerances even at varying compressor inlet conditions. Siemens supplies specialized, highly-efficient and reliable single stage centrifugal compressor packages for aeration needs satisfying these demanding requirements.
The application of aeration technology in waste water treatment
Increasing demands for quality and tougher legislation on environmental issues creates need for the best possible control of the aeration process. With the rapidly accelerating automation of waste water treatment plants, choosing the most appropriate technology is no longer sufficient. It is now increasingly important to identify the overall configuration that provides maximum efficiency, via integrated system design.
Through aeration applications in biological wastewater treatment (activated sludge; secondary treatment phase) bacteria are cultivated and used to break down the organic matter in wastewater to achieve the required effluent quality. The activating of the sludge – meaning the cultivating of the right amount of bacteria and keeping them alive throughout the treatment – requires a reliable source of compressed air. As the influent conditions vary enormously (e.g. rainfall, seasonal changes, and varying levels of wastewater pollution throughout the day) the compressor must allow for maximum flexibility in flow turndown, while at the same time keeping its design-point efficiency.
Experience from a large number of wastewater-treatment plants has shown that the right choices for control systems and solutions rapidly give full pay-back in terms of energy savings and ensure full compliance with legal requirements regarding the effluent.
Advantages of aeration process over conventional methods for waste water treatment
An automated air-supply system assures the lowest system-operating pressure, thereby keeping power consumption to the minimum. Also, continuous monitoring of process variables such as dissolved oxygen and ammonium ensures the lowest air flow delivery, optimizing the aeration process and minimizing power consumption. The precise, continuous air-flow control makes it possible to enable maximization of the more complex nitrification/denitrification process, as required in the most modern aeration processes. The air-supply system automation eliminates the need for direct operator intervention and optimizes process control, ensuring superior effluent quality.
The environment friendly aspect of Siemens compressors
As approximately 60% of wastewater treatment energy consumption can be attributed to the oxidation process, the compressors are made according to plant specifications thereby consuming significantly less energy. Also, the high quality compressor components and the conformity with technical standards for a broad range of applications ensure long-term reliability and minimum maintenance. As each compressor technology has specific advantages and disadvantages, our specialists objectively select the best suitable technology based on total cost of ownership and project and plant specific requirements. With more than 7000 units operating worldwide, Siemens has helped save excessive energy consumption when compared with alternative technologies.
Scope of operations in India
The country presents tremendous opportunities as it has already shown an inpressive development and is leapfrogging ahead of other countries. The high speed low pressure technology of the compressors can be used for industrial as well as municipal waste water treatment. We are already in advanced stages of finalizing our first project in the country and are also planning to approach city municipal corporations.
The need for energy efficiency is increasing and Indian companies now prefer new technologies over conventional methods. Our centrifugal compressors for large applications are the most energy efficient and are customized as per client needs. In addition, the life of 20-25 years of the compressors makes it low cost investment in the long run for the clients. We believe in the Indian market and want to make our presence felt by expanding business and creating awareness.
However, India with its huge poulation and incresaed building construction activity needs to focus more on environmental issues. What is required is that like in other countries where EPC contractors have to follow strict regulations and specifications, in India too implimentation should get stringent for the specifications of the installations.