Aerzen presents the first Rotary Lobe Compressor

Phil Black - PII Editor 06/12/2010

93 5 minutes read

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Aerzen Delta Hybrid – Innovation from tomorrow’s world!

Relying on experience in the design and production of rotary lobe blowers since 1868 and screw compressors since 1943, Aerzen has continually set new standards for quality and innovation in the field of twin-shafted positive displacement machines. Aerzener Maschinenfabrik is amongst the pioneers of compressor technology and is today one of the leading manufacturers worldwide.

1960 saw the launch of the world’s first compact blower arrangement, 1987 saw the development of internal pulsation dampening and 2006 saw the launch of the fifth generation of blowers – the G5. This model range has proven extremely successful due to its in-built qualities of ease of use; ergonomic design regards maintenance, low noise levels and high reliability of operation and remains a market leader today.

This unique combined experience from the worlds of rotary lobe blowers and screw compressors is the foundation upon which the new groundbreaking and future-oriented Delta Hybrid technology has been developed – the first series of Rotary Lobe Compressors.
Delta Hybrid is a synergy of blower and compressor technology. By combining the technical advantages of both concepts it offers completely new possibilities for generating positive pressure or vacuum in air and neutral gas applications.

A total of 7 patents or patent applications currently make the Delta Hybrid one of the most innovative products in compressor technology. While low pressure applications call for the Roots-principle of isochoric compression, the screw compressor with its internal compression ratio offers greater energy efficiency in higher pressure ranges.

The package concept is based on the well known and successful Aerzen Delta design (Delta Blower and Delta Screw) but has been systematically upgraded. These compact packages already offer class leading noise enclosures, carefully designed to minimise noise, allow safe but easy access to filters and provide an optimized air flow arrangement that prevents warm discharged air from short circuiting and being dragged in on the inlet side. The current Delta Package design also features an external oil-level indicator that can reliably be viewed even when the machine is operational – reducing downtime and simplifying the work of operators.

Aerzen have listened to customers worldwide to understand what tomorrow’s requirements will be and a clear message was received that power costs were increasingly an issue. Over a ten year operating period energy costs equate to about 90% of the total Life Cycle Costs of a compressor. With this in mind, the Delta Hybrid was developed with the focus on increasing energy efficiency and achieving a significant reduction of energy costs and greenhouse gas emissions.

The ideal union of both rotary lobe blower and screw compressor technologies resulted in the Delta Hybrid, a future-oriented innovation that reduces the energy consumption by up to 15% compared to current market leading designs.

A 3+3 twisted rotor profile is used for low pressures applications up to 800 mbar (12 psi) whereas a 3+4 rotor profile is used for pressures up to 1500 mbar (22 psi): the result is that a machine with optimised efficiency can be selected for the required pressure range. A newly optimized fluidic design of inlet and discharge ports provides for ideal flow conditions and reduced slippage. Inlet air is sucked in on the cold side of the package and insulated discharge silencer isolation helps to maintain a low inlet temperature therefore increasing the compression efficiency. Moreover, the belt-driven Delta Hybrid offers the significant advantage of providing exact design sizing to suit the requirements of the application. This differs to direct drive designs which utilise standard gear ratios and which inherently produce inbuilt inefficiencies. In other words, a machine supplied which provides a 5% excess in volume flow corresponds to a 5 % higher energy use, whereas the Delta Hybrid package which uses belt-drive does not suffer from this over sizing and energy wastage.

The new Delta Hybrid-series distinguishes itself by the following advantages:

•    Especially favourable price performance-ratio considerably below the investment-, energy- and maintenance costs for a comparable turbo- or screw compressor
•    Energy savings of up to 15 % compared to conventional blowers and compressors
•    Low maintenance and service costs; reliability and durability
•    Very wide flow control range from 25% to 100% and highest efficiency even at partial load
•    Robust bearing design (Lh10 of up to 60 000 operating hours even under maximum load)
•    Low compressed air discharge temperatures thanks to excellent heat management
•    Compact design that allows Side-by-Side installation
•    Automatic belt tension by means of hinged motor mounting plate, operation and maintenance access from the front, oil level check from the outside even during operation
•    Low noise levels as standard
•    Suitable for outdoor installation

Another essential advantage of the new Aerzen Rotary Lobe Compressor is the extension of the range of application and increased pressure capabilities. By design, conventional rotary lobe blowers are limited to a differential pressure of 1 bar (15 psi). When it comes to higher pressures other types of compressors are used. These are often designed for significantly higher pressures and at higher initial investment. The new Delta Hybrid now closes this gap with a differential pressure capability of 1.5 bar (22 psi). Vacuum operation can now be extended from -500 mbar (-15”Hg) to -700 mbar (-21”Hg). In addition, the safe discharge temperature limit of the Aerzen Delta Hybrid has been raised to 180 °C (356ºF), enabling full load operating in especially warm climates.

Similar to its predecessor, the Delta Hybrid stands out for its outstanding reliability and long life cycle. In wide-ranging research, Aerzener Maschinenfabrik developed new seal solutions at the drive shaft and at the rotor chamber to minimize the natural wear. A new Aerzen patented bearing system extends the bearing life to Lh10 exceeding 60 000 operating hours (at a differential pressure of 1000 mbar (15 psi).

As in previous generations the Delta Hybrid features a purely reactive discharge silencer. Since absorption material breaks down over time, Aerzen has avoided its use to prevent contaminating the downstream process system. This makes it suitable for use in pneumatic conveying systems in the food industry, reducing potential costly cleaning and interruption of production.

The new Aerzen Delta Hybrid packages have been designed for oil free compression of air and neutral gases and find application in varied industries such as wastewater treatment plants, chemical industry, power generation plants, or for the pneumatic transport of powders.

Aerzen now have the ability to offer a range of low pressure high volume oil-free package solutions to exactly suit all customers’ requirements. Delta Hybrid sits ideally between the current G5 Delta Blower packages, designed to operate up to 1000mbar and the VM/VML screw compressor packages, designed to operate at between 2 and 3.5 barG. Selection tools used by the Company allow each application to be sized and an optimal machine selected. Whole Life Cost calculations can be provided comparing the different technologies which reflect the varying capital, operation, and maintenance and power costs for a 20 or 25 year lifetime. The result is the presentation of all Aerzen technologies side by side, giving the end user the choice according to their own Companies strategies, objectives and goals.

For further information please contact;

AERZEN MACHINES LTD.
Aerzen House, Langston Road
Loughton, Essex, IG10 3SL
United Kingdom

Phone: +44 (0) 20 8502 8100
Fax: +44 (0) 20 8502 8102

E-mail : sales@aerzen.co.uk

www.aerzen.co.uk