Heating efficiently with lost heat AERZEN blowers for heat recovery Blower technology plays a functional key role in wastewater treatment plants, but causes the lion’s share of the operational costs. For the highest possible level of energy efficiency, the Wertach wastewater treatment plant relies on energetically optimised AERZEN Delta Blowers. Moreover, this wastewater company has invested in a heat recovery unit – a promising green trend in the wastewater industry. Heat recovery is a promising green trend in the wastewater industry Harald Gerbeth, manager of Wertach wastewater treatment plant When we were faced with the decision to invest we were wondering who offers technology for effective heat recovery - and found AERZEN. Three energetically optimised AERZEN Delta Blowers play an essential role in heat recovery at the Wertach wastewater treatment plant.When it was decided that the 23-year-old oil heating system in the operations building required renovation, the main consideration was to arrange its replacement. However, in parallel with this decision process, they had the idea of using the heat coming from the three positive displacement blowers to heat the room and the warm water. “The awareness developed continuously”, reflects Harald Gerbeth, head of the wastewater treatment plant. Physically related waste heat originating from the compression of air, mainly during the warm summer months, was recognised as having unexploited potential. It is important to understand that Wertach is one of 15 award-winning communities in Bavaria which have been particularly successful in their commitment to dealing with climate change as pilot communities under the European SEAP project (Sustainable Energy Action Plan).Utilise heat from the process airConversion of the wastewater treatment plant was translated into action during the three-year SEAP-project phase. The objective was to extract heat from the blower air and use this to supply the hot water for the heating system boiler. With this system, the air coming from the AERZEN positive displacement blowers flows into the air-water plate heat exchanger with a temperature of 68 degrees C and leaves it in direction to the aeration basin with a temperature of below 30 degrees C. “Thus, we are utilising a delta of about 40 degrees”, underlines Gerbeth. The system works simply but effectively: in case of low heating requirements in the operations buildings, a mechanical flap in the piping can be set so that the air coming from the blowers is fed into the basins without any detours. When the requirement for heating is high, the volume flow can be channelled through the heat exchanger completely or partially before the air reaches the basin. To ensure that the heat recovery does not affect the operational costs of the blowers, flow-optimised profiles are installed in the plate heat exchanger. The pressure losses are only about 0.05 bar with a delta p of about 0.5 bar. “After all, the Delta Blowers are primarily destined to supply air for aeration of the basins and not to generate heat”, wastewater manager Gerbeth, who heads the wastewater treatment plant of the community Wertach as independent contractor, makes clear.Simple and efficient technologyThe wastewater treatment plant, located in the Allgaeu region, has a total of three Delta Blowers (GM 4 S, Vmin 46 m³/h, Vmax 342 m³/h) with an installed power of 7.5 kW each. Combined into a cascaded group, two Delta Blowers with fixed speed cover the permanent base load. The third positive displacement blower works with variable speed, to adjust the volume flow energy-efficiently to requirements. All in all, the technology installed in Wertach is nearly maintenance-free, as the construction with only two pumps, a small control system and a buffer storage with feelers and the self-cleaning plate heat exchanger has been designed effectively and simple. And the linkage of the positive displacement blowers including heat exchanger installed was simple. For transport of the recovered heat they only had to recess an isolated pipe including control cable in the floor. The connection to the preserved heater network is accomplished via a used buffer storage, which was not needed anymore at the Wertach primary school. The overall costs for the modifications amounted to about EUR 13,400. The annual savings of fuel oil, of 1,850 litres on average, correspond to about 1,000 Euros and five tons of CO2. The example at Wertach shows how energy efficiency can be increased easily and with short ROI periods with currently available technology. Gerbeth sees the highest potential in linking positive displacement blowers and plate heat exchangers mainly for smaller wastewater treatment companies. So, heat recovery from process technology is becoming ever more important. AERZEN is closely tracking this trend and providing engineering support, so that positive displacement blowers and heat recovery are perfectly in tune with each other. Moreover, in the medium-term we recognize that in blower technology heat recovery will have an even greater influence on the design of the complete solution.
CE-marking for AERZEN Vacuum Blowers At the beginning of this year, following a new evaluation, AERZEN vacuum blowers of type HV and CM are complete machines, having attained the valued CE marking. This provides considerable simplifications for customers. AERZEN has re-evaluated with success the distinction between a complete and an incomplete machine through a new legal opinion for the purposes of the Machine Directive.
A new look for Aerzen Turbo The successful Aerzen Turbo-Series TB has been updated: The innovative system was specially developed for biological wastewater treatment plants with small and average volume flow requirements. Now, the series TB, which, at present, is available in eleven sizes, has been the subject of numerous constructive adjustments, through which energy consumption has been reduced by up to six percent. The small dimensions of the TB series results in extremely high power density. Moreover, the air conveyance has been optimised. Due to the separation of electrical and mechanical technology, heat losses are not transmitted to process air and the efficiency and reliability of the electrical technology is increased.
News from the AERZEN site After a one year construction period, the new production hall in the centre of the AERZEN premises is now ready to move into. The processing machines, which had been enclosed, or put in temporary storage during the construction period, have restarted their production operations. In another section, a portal milling machine has been replaced by a new Uniport 7000. This ultramodern machining centre has a mobile portal with a fixed table, which allows flexible and precise multi-sided machining of large components, such as pistons and housing parts. Thanks to the changeover to a Siemens Sinumerik 840D control system, the Uniport 7000 can be programmed with 3D data.
Service location South re-staffed Due to the continuously increasing number of machines to be serviced and customers to be supported in this region, AERZEN decided to re-staff the Service location Blaubeuren/South: since mid 2015, service technician Izudin Licina has been responsible for postal code area 7, and Markus Mühlbauer for postal code area 8 and parts of area 9.
New representation in Vietnam AERZEN wanted to strengthen its presence in Asia and thus established a new representation in Ho Chi Minh City, Vietnam in the middle of last year. Since 6th July 2015, Nha Ca Nguyen has been responsible for all local business developments. In future, Nha Ca Nguyen will work closely with sales engineer Edmund Tan of Aerzen Asia Singapore.
New Sales Manager for Iran Jalil Pazoki is the new AERZEN Sales Manager for the Sales region of Iran. Since 1st October 2015 he has represented AERZEN from his office in Tehran. Pazoki has both German and Iranian nationalities, studied electrical engineering, and in his previous roles he worked for system manufacturers and other engineering companies, and as a project and sales engineer in Iran, where he was able to make contact with numerous AERZEN customers.
AEO-F Certificate extended After a successful monitoring on 14th December 2015, the main customs office Hanover has renewed the AEO-F certificate for AERZEN. As Authorized Economic Operators AERZEN‘s customs procedures and export of goods operations are streamlined, so that a fast and secure supply chain can be guaranteed for the customer.
