man in blue with helmet

Edition 01/2018

Article and compact news


Turbo-Hybrid symbiosis: The chemistry is right here

Thanks to AERZEN blowers and smart global control system, DOW increases the energy efficiency of the wastewater treatment plant

Thanks to AERZEN blowers and smart global control system, DOW increases the energy efficiency of the wastewater treatment plant.
DOW produces cellulose-based chemical precursors at Bomlitz in Lower Saxony. The communal wastewater treatment plant operated by an American chemical group is accordingly designed to treat the chemical wastewater originating in production. DOW has now used a modernisation of biology to use an intelligent, fully automatic combination of flow and displacement machines from AERZEN in its blower technology.

AERsmart from AERZEN has the task of optimally distributing the amount of air, required by the aeration energetically optimal to the blowers installed at the Bomlitz wastewater treatment plant. This wastewater treatment plant is located about 1.5 kilometres from the DOW chemical plant.

Cellulose is an important construction material of nature and stabilises plants and trees. It is the main component of plant cell walls and is made of wood or cotton. DOW uses the basic properties of cellulose in the Industrial Park Walsrode (Heath area) and produces derivatives which can develop a wide variety of properties depending on their composition and processing. Some gel at high or low temperatures, others form films or stick, some make liquids differently viscous. Due to their water-binding, thickening and adhesive properties, these derivatives are in demand for a large number of products. In the food and pharmaceutical industries, for example, they replace gluten in baked goods, help to reduce the fat content in food and enable the delayed release of active ingredients in medicines. In the construction sector, methyl cellulose provides the right properties in tile adhesives, wall plasters or mortar.

Communal wastewater treatment plant for chemistry and municipalities

Sebastian Göritz
Sebastian Göritz, wastewater treatment plant Bomlitz: That‘s an innovative thing.

The waste water arising from production is treated in the wastewater treatment plant 1.5 kilometers away from the factory. DOW operates the 350,000 EWG (population equivalent) plant as a communal wastewater treatment plant, thus also taking in the municipal wastewater of the city of Bomlitz and the surrounding villages.
In the course of continuous modernisation, the company replaced three turbo blowers equipped with magnetic bearings and causing more and more expenses in 2017. Today, a combination of two AERZEN turbo blowers with air foil bearings and one Delta Hybrid package supplies the aeration tanks of biology. With a rated motor output of 150 kW each, the two AT200 turbo blowers deliver an intake volume of 5340 cubic metres per hour at a maximum differential pressure of one bar.
Both assemblies cover the base load in the communal wastewater treatment plant and run with an average differential pressure of 0.8 to 0.9 bar, according to Sebastian Göritz, assistant foreman. Both turbo machines are operated via an integrated frequency converter so that the volume flow conveyed can be adjusted according to the load operation with a regulating range of 40 to 100%. Decreasing oxygen demand leads to the gradual shutdown of both base load devices, as the efficiency of turbo machines decreases drastically with low speeds. “In this case, the Delta Hybrid takes over the air supply”, explains Sebastian Göritz. In contrast to the flow principle of the turbo compressors, in partial load operation the displacement principle makes the rotary lobe compressor accordingly more efficient due to its high regulating range of 25 to 100% in low volume flow requirement. With the installed Delta Hybrid type D 98 S, the volume flow conveyed amounts to 5800 cubic metres per hour with a motor power rate of 200 kW.

The Hybrid represents the very best of both worlds

The AERsmart global control system controls the combination of the three blowers autonomously. The remote terminal solution has its own visualisation with touch pad.

AERZEN combines the operating principles of positive displacement blowers and screw compressors in the Delta Hybrid, providing an energy-efficient solution. The machine uses the Roots principle of full pressure compression in low pressure ranges and the screw compressor principle with internal compression in higher pressure ranges. Compared to conventional compressors, this type of machine reduces energy consumption by approx. 15 percent.
However, the communal wastewater treatment plant in Bomlitz goes a big step further in terms of energy efficiency, and combines turbo blowers and rotary lobe compressors into an overall system that is independently optimised thanks to the AERsmart AERZEN global control system. “That‘s an innovative thing”, says Sebastian Göritz. AERsmart is designed to optimally distribute the air volume requested by the control room to the connected assemblies. This distribution is based on the available technologies and the associated characteristics and efficiencies. “The controller decides which machines from the pool are operated with which performance data to achieve the best overall efficiency”, says the wastewater master at DOW. AERsmart thus goes far beyond cascading with speed control and always runs the machine pool at the energetic overall optimum. The AERsmart control is equipped as a remote terminal with a visualisation on a touch display. The operational staff can immediately see the operational state on site and can read the current key figures of the connected assemblies or transfer them into the control room. Sebastian Göritz is confident that plant modernisations in this intelligent form will continue to increase. “Machines that have an ideal speed range should also be operated there”. Savings in energy consumption of at least 15 percent speak for themselves, especially as most electricity is consumed in biology.


Stepping in for low loads: The Delta Hybrid distinguishes itself by a high energy efficiency even in partial load operation.

In view of the new efficiency improvements offered by Industry 4.0 for wastewater treatment, in future, DOW intends to monitor the partial streams more continuously in Bomlitz. Online analytics in particular offers very good development potential. “In the case of carbon suppliers, we have to carry out the measurements where the carbon is produced and not only in the wastewater treatment plant. We are in a position to act instead of just reacting”, explains Sebastian Göritz. The connection of the AERsmart control to the control level is just as much the right way in this context as the control of freight quantities on the basis of actual values.

Compact news

Securing subsidies for energy efficiency

Thanks to public subsidy programmes, energy efficiency now has a double pay off. In order to exploit this potential, AERZEN will offer its customers comprehensive support in the areas of energy efficiency, energy recovery and resource management together with the state-subsidised e.qua network. The climate protection targets adopted by the German government are accompanied by numerous subsidy programmes that can be used by operators of water management facilities. A distinction must be made between concept and investment subsidies for energy in the context of climate protection.
Customer-oriented support by AERZEN and e.qua ranges from measuring volume flow requirements, energy analysis and optimisation and the preliminary clarification of suitable funding options for energy concepts to support in applying for funding.
One example is sewage treatment: wastewater treatment plants are among the largest energy consumers in municipalities. With the latest technologies, considerable amounts of energy can be saved. In order to meet the increased requirements of the water and wastewater industry, AERZEN has paid special attention to the energy efficiency of its assemblies. In addition, well thought-out solutions for waste heat utilisation can be provided. AERZEN thus also meets the political targets set for energy efficiency and energy generation.

Delta Blower series extended

Delta Blower series extended

With the Generation 5 positive displacement blowers AERZEN has set new standards. Now, the series is extended by two new blower stages: GM 110 S and GM 130 S types close the gaps in the volume flow range. The figures “110” and “130” stand for intake volume flows of 110 and 130 m³/min respectively (6,660 and 7,800 m³/h). Previously, there had been a jump from 90 m³/min (5,400 m³/h) to up to 150 m³/min (9,000 m³/h) and with it also a jump in the nominal diameter from DN250 to DN300. With the new blower sizes, this volume flow range is now finer graded, which brings decisive advantages for plant manufacturers and operators in terms of investment costs, dimensions and control range.
What is also new: the enhanced Delta Blower series G5plus. Energy efficiency is currently the most important focus, particularly in the field of compressor technology where energy costs exceed 90% of the life-cycle-costs. AERZEN has always been a standard setter to develop more efficient and environmentally friendly processes. To expand upon the success of the AERZEN Delta Blower series, an exciting new design sets energy saving records. The new G5plus series distinguishes itself by increased energy efficiency of up to 5% and significantly reduced dimensions.
Experience the new blower sizes at the trade fair stand of Aerzener Maschinenfabrik at the IFAT in Munich and the ACHEMA in Frankfurt.

This is AERZEN Performance³

This is AERZEN Performance³

AERZEN defines Performance. as an individual solution for the oxygen supply of biological aeration in waste water technology. Individual assemblies of Delta Blower positive displacement blowers, Delta Hybrid rotary lobe compressors and Aerzen Turbo blowers of the AERZEN range of products or a combination of assemblies of different efficiencies and regulating ranges can be used.

What is so special about Performance³

Every technology has its strengths, but is also subject to physical limitations. By means of a possible technology mix and the use of different sizes, the individual strengths of assemblies can be added to a highly efficient combination with the best control range. The AERZEN Performance³ concept takes into account the respective requirements of a plant and offers you a rightsized solution that suits you and your plant perfectly. You will be supported by AERZEN wastewater experts during the entire process until your Performance³ solution is found.

How does AERZEN proceed?

In a first step, the load profile of a wastewater treatment plant is evaluated and important parameters for the following calculations are determined. If this load profile is not known it makes sense to record the measured value before. For this purpose, AERZEN uses its AERaudit product which is used to measure the volume flow and other important variables during operation of a plant (see page 2).
An analysis of the recorded load profile forms the basis for the Performance³ process. At the beginning, the solution space consists of a multitude of variants. Taking your plant requirements into account, AERZEN will develop the Performance³ solution that best suits you and your plant.

New Head of Opportunity Engineering in Supply Process Gas

On 1 September 2017, Carsten Holldack assumed responsibility for the group Opportunity Engineering in the Supply Process Gas division. The graduate mechanical engineer, born in 1970, has more than 20 years of professional experience in the field of rotating equipment. His previous roles were in development, product management and salesmanagement. The “Opportunity Engineering” group at the Aerzen site, led by Holldack, consists of six experienced process gas specialists.

Klaus Peter Glöckner new member of the General Management

Since 1 December 2017, the General Management of Aerzener Maschinenfabrik consists again of three persons: Graduate engineer Mr. Klaus Peter Glöckner completes the Management team and has got to know the company intensively over the past few months. Klaus Peter Glöckner is responsible for the EMEA region. He was previously employed as Chief Sales Officer and Managing Director at Messrs. Kelvion.

Aerzen Colombia celebrated its 10th anniversary

On 27 September 2017, Aerzen Colombia S.A.S., based near the capital, Bogotá, celebrated its tenth anniversary. The subsidiary, which when it opened was called Aerzen Andina, started out as an agency of Aerzen Iberica. This developed into two separate subsidiaries - Aerzen Colombia, which now has 15 employees, and Aerzen Andina Peru, where four colleagues are currently employed. The markets in Bolivia, Ecuador and Venezuela are supervised by commercial agents. Ricardo Castillo, Managing Director of Aerzen Colombia, is pleased about the tenth birthday celebrations: “We hope to be able to celebrate many more anniversaries and to contribute to the growth of the AERZEN group.”