AERZEN turbo blowers. Over the decades we have developed these packaged units to technical excellence. In doing so we have acquired expertise that sets standards throughout the world. This is reflected in improved energy efficiency, low life-cycle costs and specially developed core components. To sum it up: it can be seen in every detail of AERZEN’s continuous flow machines.
Construction and functional principle of a turbo blower from AERZEN are simple and at the same time effective. As the air supply of modern wastewater treatment plants is clearly designed for maximum availability, high energy efficiency and long maintenance cycles, AERZEN uses for the demanding bearing system within turbo blowers neither oil nor other lubricants - but simply air.
Casestudy WWTP Emsbüren
Casestudy WWTP Wallau
Turbo blowers and/or turbo compressors are extensively used in sewage treatment. Reliability, energy efficiency, and reduced maintenance costs are extremely important. Turbomachines particularly must do their jobs without major interruptions due to maintenance and repairs - they boost air into the aeration tanks.The air supplies the microorganisms into the basin with oxygen. The more efficient the aeration, the better. Tasking this takes tremendous effort. To enter the necessary oxygen into a basin, the flow machines must function smoothly in a harsh environment over long periods of time.In this case, "frictionless" is known within the context of contemporary innovation; since conventional ball bearings or other mechanical bearings, which always cause some amount of friction; are not practical at the high-rotational speeds, generated inside a turbo blower. Ergo, turbomachines in sewage applications require bearings that operate without mechanical friction, and ensure a smooth operation of the turbocharger during the compression process.
In principle, there are two approaches for the implementation of a friction-free and non-contact bearing of Turbochargers: Magnetic bearing and air bearing. The non-contact bearing also eliminates unnecessary maintenance like lubrication (e.g.: Oil). Therefore, modern speed-controlled turbos are also referred to as "oil-free" high-frequency Turbo Compressors. Previously and for the longest time, magnetic bearings were the most practical solution.This type of bearing generates corresponding magnetic fields into the interior of the blower, completely avoiding contact between the fast-rotating shafts and other components. This solution is highly complex, and the implementation is also quite technically complex. To ensure a smooth function, the system must constantly check the exact position of the shaft. Only then, can the electric currents adjust the magnetic fields as precisely as necessary, for trouble-free continuous operation.The use of finely calibrated sensors and the overall complex control circuit also has disadvantages. On one hand, certain environmental conditions are often not ideal for sensitive components; especially in sewage treatment plants. On the other hand, the complex controls require regular maintenance. Additionally, there is high sensitivity in operating and processing pressure fluctuations and peaks, and technologic aspects such as the compressor pump.For both, dynamic forces that work on the rotor of the machine are created. Due to their complex control circuit, magnetic bearings are rather more limited with regard to robustness, and are quickly switched-off in extreme situations. This results in a frequent failure of the turbomachinery on many systems.One of the most significant drawbacks is the very limited service possibilities. If something needs to be repaired or replaced, it cannot be done at the installation site; only at the manufacturer. This means, in addition to planning the logistics of it all, a critical and possible three-month waiting period for the machine. Regarding the balance of power, the magnetic bearing is not ideal, because a constant production of power is required for the generation of the magnetic field; which increases the turbocharger’s operating costs. Additionally, a backup battery must be provided for an emergency, in case of an interruption of the power supply.The so-called UPS (Uninterruptible Power Supply) ensures that the high-frequency rotating rotor does not immediately come across the mechanical emergency bearing when the power supply fails. The workload on the emergency bearing would be so great at full-speed, costly damages would be highly likely. The UPS can also be switched off, only after the speed decreases to a safer and manageable level. Because the installed batteries must be fully charged and stabilised, a UPS also requires its own maintenance.The battery packs must be regularly checked using a special maintenance plan, and replaced when there are damaged or older/weaker battery cells. Overall, the solution by magnetic bearings is more expensive over the long term, technically overcomplicated, and energy inefficient. Hence, this is why AERZEN relies on another system.
The air bearing is used as standard solution in the Turbo Blowers of the AT and TB Series. The value of non-contact air bearings has enormous advantages over mechanical and magnetic solutions. Functioning value and operation features within the turbos are based on very simple physical principles. The motor shaft connected to the impeller must be precisely borne: a task that cannot be met with current industry standards for bearings, due to the high rotational speeds.AERZEN's air suspension for turbo blowers offers significant advantages of simplicity and energy-efficiency. Compressed air is used in both radial bearings of the drive shaft, and in the axial bearing as air pockets.The air does not come from an external generator, rather is produced by the turbo blower itself; just like with conventional compressors. When the blower is switched on, the shaft produces an alternative circular movement. This increases the pressure in the minimum clearance to the bearing wall, which again presses the shaft in the opposite direction. The high speeds ensure automatic centering of the shaft in the bearing, and increases the operating pressure in the air pocket to more than 30 bars (435 psi). The high pressures generated ultimately result in a free-floating operation of the shaft, centered in the bearing. This type of bearing was also developed for space travel.In contrast to the magnetic bearing, no additional energy input is required for generating the air pocket, because it automatically forms through the normal functions. Additionally, the operating costs are reduced because the bearing is completely maintenance-free. The resistance to interference caused by the simple and robust design of the system is a distinctive technological feature. Even problematic operating conditions such as overloads and pressure fluctuations are compensated simply by its physical properties.If a repair is nevertheless needed, you can replace all related components within a few hours; especially at the installation site. Contact between the friction-components in the bearing is provided only when the turbocharger is turned on or off, or when the air pocket is built up. To prevent premature wear, AERZEN uses an innovative air foil bearing.The bearing and shaft are provided with a two-component coating of graphite and Teflon, which have a high temperature as well as a friction tolerance and resistance. This double "anti-stick coating" significantly reduces mechanical overloads and wear-and-tear during machine start-up.
The AERZEN Turbo generators set new standards when it comes to everyday upkeep, scheduled maintenance, and energy efficiency. The modern turbo compressors are extremely robust and can be used effortlessly within 24-hours of operation in sewage treatment plants and other areas of sewage technologies. In contrast to FLW machines from other manufacturers, the blowers of the TB and AT Series are also suitable for SBR Systems (Sequencing Batch Reactor), due to their control range and the idle operation mode option. The idle mode is much more energy-efficient than constantly switching on-and-off the entire system.Of course, all relative parameters of the turbo fan can be gauged in real-time. A good highlight of this is the real air quantity measurement, which is indirectly derived from the power consumption of most other manufacturers. The AERZEN system uses the so-called “Venturi Principle;” which interprets the air mass, sucked in by differential pressure measurements.This technique allows you to see the air volumes currently being pumped at any given time. The operating performance of sewage treatment plants can significantly be enhanced, based on the determined values. In the long-term, the efficient development of services has a positive impact on energy consumption. The purchase price of the compressor pays off relatively quickly from saved energy costs and, thus, hardly has a long-term effect financially. In sewage treatment plants, more than half of their energy demands are spent on maintaining aeration to the supply basin.Therefore, it may be more practical to change to a modern system. For example: a combination of turbo blower, rotary piston blower and rotary piston compressor; a so-called "blower composite.” Short-life cycle costs and adaptable logistics and operations make the AERZEN systems particularly attractive. The scope and size of the system determines the basic conditions of the respective installation. With this, AERZEN offers customised products and solutions - especially when retrofitting older systems, which is an extremely important factor for our line of work. No matter which product you choose from AERZEN, all our products are manufactured with the highest quality and built specifically for longevity and efficiency.