Though two-third’s of the earth’s surface is covered in water, most of that water does not satisfy the need of human life. That’s why wastewater treatment plays a vital role to treat water contamination. As per provisions of The Environment (Protection) Act of 1986, in India, Effluent Treatment Plants (ETPs) are to be installed by industries for wastewater treatment.
Low-pressure blowers play a critical role in ETPs. Though lobe blowers are commonly used, a range of screw technology have been developed with the aim of providing a reliable low pressure for this application. Understanding technology and identifying the issue makes for a better solution.
Choosing the right technology for your business and the environment
Now, the quantity of water determines the amount of dissolved oxygen required, based on the Biochemical Oxygen Demand (BOD), which is the oxygen consumed by bacteria to decompose organic matter at a certain temperature. This determines the amount of air or oxygen needed, and the height of the water column determines the back resistance pressure, along with any additional resistance in the pipeline. The higher the tank, the better the oxygen transfer efficiency. This is because, as oxygen travels inside the tank, the air bubbles take more time to reach the surface, resulting in improved oxygen transfer into the tank.
What helps to reduce operational costs in Wastewater Treatment Plants (WTPs)
Focusing on operations, the initial cost of a low-pressure blower may represent only 5% of an ETP’s total investment. However, the operational cost of aeration blowers can account for about 80% of a WTP’s energy expenses. Therefore, selecting efficient blowers is a priority, as they must operate continuously to supply oxygen to microorganisms in the ETP.
Benefits of oil-free screw blowers over tri-lobe/root blowers
Operating principle: Tri-lobe blowers utilize external compression, where air is compressed outside the lobe block, maintaining a constant internal volume. As the lobes rotate, they move a set air volume from the inlet to the discharge side. Compression occurs due to backflow, with a maximum of 1 bar. Conversely, screw blowers employ internal compression, reducing air volume within the male-female rotors. The fixed screw element prevents mechanical imbalances, allowing high-speed operation.
Enhanced energy efficiency (up to 40%) Water columns typically exert a back pressure of 0.5 – 0.8 bar(g) on aeration blowers. Tri-lobe blowers are efficient up to a 4 m water level in aeration tanks, with a back-pressure resistance of 0.45 bar(g) or less. Beyond 0.5 bar(g), they consume more power, raising ETP energy costs. Screw blowers, recommended for pressures above 0.5 bar(g), are about 30% more energy-efficient than lobe blowers. Atlas Copco’s direct-coupled/gear-driven screw blowers surpass belt-driven models in efficiency, with less friction loss and higher transmission.
Improved water quality: Class 0 certified oil-free screw blowers ensure water integrity by preventing oil from entering the air during compression. Solutions are available for both small and large capacity plants, with a broad selection to meet specific needs.
Atlas Copco has variety of ranges of blower to meet the expectation of customer. Also provide reliable solution for different applications. To know more on different application for Wastewater treatment process or check the existing layout of your plant is efficient, connect to our low-pressure experts
