Efficient Aeration Motors Help Wastewater Aeration System Cut Costs by 50 %
Wastewater treatment is an essential operation but it can require a large amount of energy, which makes it an excellent opportunity for improvements in efficiency. Some manufacturers that use large amounts of water, employ their own treatment facilities, all of which can benefit from experience in meeting the demands of this sector.
The fresh food manufacturer Ter Beke had a goal of reducing the energy costs at its Wanze treatment plant by 50 % — an ambitious target that has been the focus of a project involving the companies Kamps, a leading manufacturer of water treatment equipment, and WEG Benelux. Together with Cofely Services, which maintains the treatment works, the project has redesigned the aeration system for the wastewater and has projected some very significant savings.
Ter Beke has championed sustainable entrepreneurship for many years and has made significant investments to reduce the company’s environmental impact. Since 2008, the company has reduced its water consumption by 30 % in the plants where it manufactures meat products and primary energy consumption has been reduced by 10 %. As a further commitment to the environment, all of the electrical power used by the company is generated from green resources.
The project focussed on the high speed aerator that was used to increase oxygen levels in the activated sludge tank and also maintain the solid particles in suspension ensuring a more efficient treatment process. Luc Pahaut, Technical Specialist at Cofely Services, explains: “Given that the energy costs of this solution were relatively high, we began to look for a new solution. Three quarters of the investment at Ter Beke was made with the aim of further reducing energy consumption”.
On the search for energy-efficient solutions
Having identified the main area for improvement, designers from Kamps were assigned the task of delivering a new aerator that would achieve the required oxygen levels and mixing characteristics whilst significantly reducing the energy costs.
Alain Mineur, CEO of Kamps, comments: “The specific low-speed aerator, known as the Airmax, was selected which has appreciably reduced operational costs and the aerator does not require any maintenance.” For the drive system the company once again selected WEG, having worked together successfully in the past. Mineur continues: “We have always had a tendency to go for energy-efficient solutions. We try to stay one step ahead of our competitors in this respect. When it became compulsory to use the IE2 motors, we were already using the standard IE3 range. At the present time we are also looking into the possibility of implementing WEG’s IE4 motors in new projects.”
Higher efficiency and better performance
WEG Benelux supplied a 55 kW W22 Premium efficiency IE3 motor, specifically designed to cope with the harsh environment of the water treatment industry. Since the motor is mounted vertically it was also fitted with a shroud on the non-drive end to reduce the risk of water ingress. The original installation had used a 110 kW motor but the new aeration system only required a 55 kW unit which had a double bonus for the operator.
The initial purchase costs of the motors was considerably less and the running costs after rearrangement were almost halved. The new improved motor design that enables higher efficiency and better performance will also ensure that the costs of the motors will be recuperated in less than two years.
Luc Pahaut concludes: “The aeration process is working far more efficiently than before; it is consuming less energy and the oxygen levels are also much better.” In fact the redesigned aerator can treat larger volumes of wastewater while operating at a lower speed.