Drive puts new life into old compressors

Edited by the Engineeringtalk editorial team Aug 28, 2002

The new Retrofit VSD variable speed drive from EnergAir will allow users of compressed air to reduce energy consumption without the capital outlay required by a new air compressor.

The new Retrofit VSD variable speed drive from EnergAir will allow users of compressed air to reduce energy consumption without the capital outlay required by a new air compressor.

Existing compressors that have become a financial liability due to increased electricity charges can now be upgraded with variable speed control to accurately match air generation with system demands and significantly reduce energy bills.

Increased electricity costs have recently brought a strong industry focus on air generation as a prime candidate for energy saving.

As a solution to improving overall system efficiency, compressor manufacturers and suppliers are currently recommending existing compressors be replaced with variable speed compressors.

Graham Coats of UK based compressed air management specialist EnergAir points out a number of disadvantages with this course of action and suggests a more economical alternative.

"While a new compressor might provide better more efficient air production, the majority of compressors operating in industry today are only part way through their life cycle and represent a capital investment that will be lost if they are replaced prematurely.

Secondly, buying one VSD compressor will not solve the problem when multiple compressors are on site, often of different brands that cannot communicate with each other".

Retrofitting EnergAir's compressor-specific variable speed drive to an existing compressor addresses both these concerns.

The cost of the drive and commissioning is a fraction of that represented by a single new compressor and so offers significant savings in capital outlay.

In addition, it will extend compressor life by controlling duty cycles and avoiding harsh on/off full-load operation, thereby protecting the original investment.

The software that is provided with an EnergAir retrofit VSD can be used with an EnergAir control system to network a series of compressors of any make to achieve full system integration.

The control system is used to track the air demand profile on site, replacing inefficient on/off cascade systems with fine-tuned air generation, ensuring maximum efficiency.

EnergAir are able to retrofit drives packages to virtually any type of screw compressor, including the more common oil lubricated types and higher speed 'dry' compressors.

Multiple compressors offer more scope for energy saving, but installation on just a single compressor can easily show pay back periods as low as twelve months.

For companies who require reduced energy costs in the future, but prefer not to make any immediate capital investment, EnergAir are also offering a complete air system control and monitoring package effectively free of charge.

By closely monitoring energy usage before an installation, EnergAir are able to accurately calculate the potential savings to be made in a system and balance those reductions against a monthly payment scheme.

Typical pay back periods range from twelve to eighteen months.

During that period, the user also has the option of free 24-hour system monitoring and maintenance support.

The control and monitoring interface is implemented in an easy-to-use windows environment using a PC and EnerSoft compressor control software.

In addition to fine-tuning control, the package also provides real-time visual indication of energy usage, system pressure, compressor load and efficiency.

Monthly reports can be compiled automatically and printed out to support internal plant-wide efficiency monitoring reports.

Provided with online access, it also facilitates EnergAir's 24h 'alert' monitoring service offering complete peace of mind to users of compressed air in continuous or critical plant processes.

EnergAir retrofit drives are based on a Control Techniques VTC drive, providing advanced open-loop control and designed specifically to cope with the real time demands of high speed pump applications.

The units are quiet and reliable in operation and also have the flexibility to interface with virtually any factory automation system via EnergAir's Enercon, energy management package.

EnergAir offers the Retrofit VSD drive, full commissioning and 24h maintenance support via a select number of specialist partners guaranteeing immediate response and impartial technical advise.