Blowers Chosen for Wastewater Treatment Re-Development Sites

Anglian Water, one of the UK’s water and wastewater treatment companies recently decided to use Atlas Copco's (UK) range of low pressure ZS blowers to help provide air to the aeration diffusers at four of Anglian Waters wastewater treatment sites.

Atlas Copco have developed the ZS90 rotary screw blowers and 22 of these will be installed across Hertfordshire, Bedfordshire, Peterborough and Essex. This agrees with Anglian Water's drive to find innovative ways to reduce energy consumption.

The process of treating wastewater requires bacteria breaking up the waste. This in turn requires large amounts of air to be blown into the aeration tanks. In normal biological treatment plants, blowing the air into the treatment plant can account up to 70% of the energy used. To help improve the distribution of air and bubbles around the wastewater containment system, Hydrok, an aeration diffuser, was approached by Anglian Water. Hydrok can provide submersible bubble aeration framework systems to distribute the air around the container.

Atlas Copco ZS helped to match Hydroks high efficiency technology with their low pressure screw blowers, this cut energy costs by up to 35%. The ZS90 range of Variable Speed Drive, oil-free rotary screw displacement blowers include a complete, fully integrated package based on: precision timed gears with minute clearances between the two inter-meshing oil free screw elements. With the two elements never touching no lubrication is required and specific seals stop any oil entering the compression chamber. Intake air is compressed between the rotors and their housing and oil-free, pulsation-free air at pressures of 550-700 mbar is delivered at an output rate of between 1300 - 4500 Nm3/h free air delivered dependent upon process demand.

Atlas Copco ZS blowers are fitted with weather proof kits to help when external installations are being made. Using the ZS range will help to allow Anglian Water in locating the blower motor inverters, controls and condition monitoring in their specially designed purpose built MCC room.

In the case of the Hertfordshire site Anglian Water chose to reduce costs for installation by installing ZS+ blowers. ZS+ blowers are supplied with an integrated frequency converter which varies the speed of the 90kW motor to match changes in the blower air demand. This helps to consume only the minimum amount of energy required. As an additional benefit, the ZS+ range of blowers are fitted with the Atlas Copco Elektronikon operating system to provide control, to monitor the overall system performance status, and to increase the blowers’ efficiency and reliability.