Reliable Blowers for Air Injection into Aeration Tanks

The Schlammersdorf-Vorbach sewage treatment plant processes household waste water for 2,900 residents of the communities Schlammersdorf and Vorbach in the Upper Palatinate region of southern Germany. Air injection into the aeration tanks is carried out by Busch Tyr blowers. Oxygen in this air is required to break down carbon and nitrogen compounds in the waste water during the aerating stages of the process. In the non-aerating stages, air impulse injection is used to mix the tank contents to a homogeneous consistency.

The sewage treatment plant is owned by the waste water treatment authority in Schlammersdorf-Vorbach, and was commissioned in 1996. The receiving water is the Creussen, a minor river that flows beside the plant. The plant uses the activated sludge process with simultaneous sludge stabilization. This purification process was chosen due to the relatively large fluctuations in demand generated by the nearly 3,000 local residents served by the plant. The entire system was installed by D.W.I. Service Sued, which also provides technical support. One of the areas in which D.W.I. specializes is the provision of technical services for waste water treatment plant, and the company works closely in this sector with the vacuum and overpressure specialists Busch.

After passing through the raking and sand trap systems, the waste water flows through a siphon into an aeration tank with a depth of about four meters and a capacity of 1,100 m3.
The simultaneous sludge stabilization achieved by extending the aeration time oxidizes or mineralizes the organic impurities. The excess sludge extracted is more or less stabilized and almost odourless.

The air injection into the aeration tank has been carried out since July 2015 by two Tyr blowers supplied by Busch Vacuum Pumps and Systems. These modern blowers were installed after the previous two blowers supplied by a different manufacturer failed completely within a short period. As the sewage treatment plant was unable to operate without these blowers, a solution had to be found rapidly. Busch was able to supply a replacement blower immediately, it was installed by D.W.I. Service Sued and the plant resumed operation within 48 hours. This temporary blower was later replaced by two Busch Tyr blowers installed in the production building. The Tyr blowers deliver intermittent overpressure at 0.5 bar with constant volume flow. As the maximum pumping speed is required only in cases of extreme contaminant load, the control system is programmed to operate both Tyr blowers at two different speeds without the use of frequency converters. This means the total pumping speed may be set to four levels, allowing enormous energy savings to be achieved. With this arrangement the control system runs the blowers for a maximum of 12 hours a day. The oxygen content in the aeration tank is monitored continuously by the control system: if it falls below a minimum value, the blowers are started automatically. The control system can determine from the oxygen content whether one or two blowers are required, and at what speed they should run. An adequate supply of oxygen is essential to metabolize carbon compounds and to oxidize ammonium nitrogen during the nitrification stage. In the subsequent denitrification stage, the nitrogen decomposition by-products are converted to nitrogen gas by microbial action. This gas is released to the atmosphere, which itself consists primarily of nitrogen.
The operating costs of a sewage treatment plant can represent a large proportion of annual expenditure for small towns and communities. The community authorities operating these systems and technical management both agree that sewage treatment must be carried out with the maximum possible economy and energy efficiency. Personnel costs at the Schlammersdorf plant have been reduced by a high degree of automation and the participation of the Grafenwoehr utility company, which receives plant alarm messages automatically. In practice the plant is inspected every working day, and all parameters relevant to its operation are examined. Technical equipment for the continuous process has been chosen for maximum energy efficiency. For example, the agitators originally used to mix the contents of the aeration tank were removed and replaced by impulse air injection. The two Tyr blowers now perform this function by introducing air through non-clogging membrane inlets at the bottom of the tank. Electrically driven agitators are no longer required.

After a year of operation (July 2016), Gerhard Maier and Johannes Zinnbauer of the Grafenwoehr utility company expressed their complete satisfaction with the two Busch Tyr blowers, which have made an energy efficient and reliable contribution to the purification of waste water in the aeration tanks.

Uli Merkle
Busch Vacuum Pumps and Systems
Maulburg, 18 May 2016

Busch Vacuum Pumps and Systems is one of the largest manufacturers of vacuum pumps, blowers and compressors in the world.
With a lot of experience and top qualified personnel, we are forward-looking and strive to improve our products and ourselves. We are constantly at work developing innovative technologies that will define the vacuum world of the future.
Our manufacturing plants utilize the most modern manufacturing techniques, machinery and equipment under very strict quality controls, which surpass DIN EN ISO 9001 requirements.
As of 2016, Busch Vacuum Pumps and Systems employs more than 3000 people and features the largest selection of vacuum pumps for the industrial applications in the world. Due to its immense line of vacuum pumps, expertise and experience in the building of vacuum systems and the extensive service network, Busch is capable of providing ideal comprehensive solutions.
With 60 companies in 42 countries and sales agencies worldwide, we are strategically positioned throughout the world to provide our customers with the essentials for success.
Our goal always is to provide the customer with the highest possible return on investment. Personal consulting, choice of the optimum product and prompt service on site are key features of our comprehensive service that make the achievement of this goal reality. Our experience and know how in broadly diversified applications and product design furnish the basis.
Busch’s headquarter is located in Maulburg, Germany. Besides Busch Holding, the German manufacturing plant, Busch Produktions GmbH, the sales organization, Dr.-Ing. K. Busch GmbH and service company, Busch Dienste GmbH are headquartered here. In addition, Busch operates production plants in Switzerland, Great Britain, Czech Republic, Korea and the USA.

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This release was published on openPR.