Helping companies to cut their costs
November 1st 2011

Applying simple non-intrusive air audit data logging techniques over a fixed period of time will establish a true indication of a system's air use and cost and help identify any waste factors such as leaks and pressure drops.Ken Revell, customer care manager, sales support group at Atlas Copco, explains

Most compressed air users would agree that to get the best return from their capital investment, the monitoring, measuring and management of compressor installations is essential if optimum control, improved productivity and energy efficiency is to be achieved. That is why Atlas Copco and its distributors carry out energy audits as the definitive approach to identifying trends, establishing how well systems are performing, and recommending energy-efficient solutions where needed.

Whether the purpose of an air audit is part of an on-going service contract, a means to monitor the progress of an established installation or to determine the efficiency of an existing system for potential replacement, the question the Atlas Copco distributor asks of the customer is 'Do you know how much compressed air you use and how much it costs to produce?' The starting point is to measure the power requirement for the compressor installation, a simple initial procedure that may be followed by a full system audit where deemed necessary.

Atlas Copco authorised distributors have applied these monitoring techniques to many diverse applications, and as a result of implementing these energy-efficient measures, it is not uncommon for operating cost savings of 40% to be realised.

For example, the Wales-based distributor Control Gear helped a bridgeworks and water engineering products manufacturer in South Wales make savings of £8000/annum following an energy audit.With the aid of iiTraks and supporting software, a potential saving of £12,000 was realised by another of the distributor's customers who make vibration dampening products in Wiltshire.

In the North West, Precision Pneumatics helped a theme park to cut its annual power consumption by 50%, and also achieved a 35% annual energy savings for a newspaper publisher. In South Yorkshire, the Compressed Air Division of the Search Group of Companies achieved £35,000 in energy savings for a large engineering plant and £15,000 per annum for a health care products manufacturer.

That is why it is standard practice within the distributor network to conduct these investigations. Every distributor in the nationwide network has the technical capacity and dedication to help compressed air users maximise energy savings and to improve the reliability and productivity of their compressed air systems.

Using iiTrak data loggers, Atlas Copcotrained engineers can help operators get an indication of a system's air use and cost without any interruption to the air supply or production process. The result is an accurate indication of a plant's compressed air demand and, importantly, of any potential waste.

The compact, unobtrusive, battery-powered iiTrak loggers have the latest data capture technology to log compressor load status via current sensing. They are designed as stand alone units, with one logger allocated to each machine in a multiple installation, or one unit dedicated to each compressor characteristic to be measured. Easily installed at point of use, they are connected by a single cable for one leg of incoming power. Data is captured by the unit's flash card memory for subsequent computer download and scrutiny.

The true amount of energy drawn by each compressor (both on load and off load) is measured. The mains voltage and power factor correction is also recorded which gives the true kilowattage consumed by each compressor. The candidate compressors are logged for a minimum period of one week after which the data is downloaded to a computer. In some instances, the user's production process programme and relevant air demand variations may require an extended measurement period; the battery power for the iiTrak units is adequate for about three weeks of operation before replacement is necessary. The Atlas Copco software programme for the iiTrak enables simulated compressor comparisons to be made against the actual system.

It is usual for Atlas Copco's iiTrak energy monitoring to take place prior to an in-depth investigation to obtain a full understanding of the air use by scrutinising every stage from compressed air production to its point of use. The audit procedure uses sophisticated devices such as a mass flow measurement meter, relative pressure sensor/transmitters, ultrasonic leak detection apparatus and power meter monitoring. These pinpoint inefficiencies such as inadequacies in the production and use of the compressed air supply, poor pipework design and pressure drop sites. They also show where systems are operating at too high a pressure and where energy is being wasted due to piping leaks.

The distributor then looks at present and future needs in depth, submits a report of the findings, and recommends solutions based on audit data and close knowledge of the application. As a result, customers can be provided with energy-efficient systems tailored to their needs. Recommendations may include energy-efficient VSD compressors that match compressor output to process demand, generating energy savings of up to 35%.

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