In a wastewater treatment project carried out by an independent association, the whole project was managed in partnership with UD Umwelt-Dienste GmbH. The result was successful, with costs going down, while there was much more freedom to choose the most suitable aeration device for the already fitted aeration tanks. A tender would have thrown up less expensive solutions of a similar quality or just as appropriate solutions for the existing setup, according to Gernot Wege, the plant manager.
The production manager believes that reasonable investment is a necessity and must not be denied based on municipal audit. He follows this up by close monitoring of all the operational aspects of the plant on site with his team. One vital factor was the oxygen demand in the aeration tanks. The right solution was, they found, to reconstruct the plant, which occurred in just over two months.
This included the installation of a combined blower system comprising of the Aerzen Turbo and Delta Hybrid blowers, with a system of linked connected Aerostrip fine bubble diffusers from Aquaconsult. This ensured that oxygenation of the tank was perfect under all circumstances. Wege says that the plant now serves 39,000 residents on either side of the river Lahn, the plant location being in the district of Marburg-Biedenkopf, in the city area of Biedenkopf.
Knowing the less than ideal aeration characteristics of the 2.65 meter deep aeration tanks which lacked the five meter depth for plate aerators to function optimally, by furnishing time for the bubbles to give off maximum oxygen as they rose to the surface, the team chose to order fine bubble aerators in quick order, prioritizing the fit of the aerator to the final requirement over cost alone.
Perfect in all Seasons
Control room staff can regulate the operation of the combined Aerzen turbo and Delta Hybrid blowers to fit the freight volume at the time. The tandem mode is primarily intended for applications that function during summer and winter. When more air is required during summer, the Aerzen turbo blower is more in use as the more efficient machine at base loads.
At peak times, the Delta Hybrid is added to boost the capacity. The AT 100-0.6 S provides a volume flow up to 4,200 m³/h with a control range of 40% to 100%. In winter, however, the Delta Hybrid takes over the main job as the oxygen requirement is reduced at this time. Type D 36 S has a maximum volume flow of 2,150 m³/h with a control range of 25% to 100%.
Wallau shows this kind of difference because of its geological peculiarity, in that the groundwater level in the sewer system is higher than in many other locations because of drainage connections. This results in very dilute waste water. The rainwater remains locked in the ground for a relatively long time because of the existence of a schist layer that prevents rain seepage around the Lahn.
With time, however, there was a marked reduction in energy expenditure, far exceeding the projected energy savings of 15 percent. The revamped system has already saved 26 percent on electricity consumption over the whole plant. The reason is that aeration needs to account for half the electricity consumption. Retrofitting the combined Aerzen turbo and Delta Hybrid blowers in this system brought about over a 50 percent reduction in costs, as well as being much more ecofriendly.
When the air demand in wastewater treatment projects is variable, it is more efficient to control it using speed-regulated or cascade-mechanism controls. Aerzen has taken a progressive step by using different machine types to build a custom combination which reduces energy consumption significantly, since each of the individual machines operate only within a preset range and at optimum effectiveness. In each case ideal blowers can be used and combined as needed.
Aerzen offers the benefit of not having to hunt for different types since it carries all the necessary components, a much-admired feature. Another benefit is standardization which adds to the ease of the whole service. The patented bearing in the discharge silencer and the lack of absorption material or oil ensures that the membrane aerator is built for long life and safe processes. Maintenance or repair is also easy, being only a phone call away.
Aerzen - Compression Spells Success
First founded in 1864 as Aerzener Maschinenfabrik, Aerzen built the first ever rotary lobe blower in Europe (1868) followed many years later by the first turbo compressor in 1911, the earliest screw compressor in 1943, and the first rotary lobe compressor in 2010.
The Aerzen spirit of innovation keeps the ideas coming, driving compressor advancement. Aerzen is among the most distinguished and the oldest manufacturers of a large range of products including rotary lobe meters, screw compressors, rotary lobe blowers, and turbo blowers.
They lead sales in many applications, with over 2,000 staff members taking control of 45 branches the world over who are devoted to advancing compressor technology. Workforce skill, experienced professors to offer their expertise, and customer feedback help guide Aerzen to new innovations. Aerzen is a pathbreaker when it comes to setting a benchmark for value, efficiency and reliability.
This information has been sourced, reviewed and adapted from materials provided by Aerzener Maschinenfabrik GmbH.
For more information on this source, please visit Aerzener Maschinenfabrik GmbH.