Compressor change leads to greener galvanising

Edited by the Engineeringtalk editorial team May 8, 2006

Measures put in place by a galvanising company in Scotland to achieve the ISO14001 environmental management standard have led the company to save many thousands of pounds in energy costs.

Measures put in place by a galvanising company in Scotland to achieve the ISO14001 international environmental management standard have led the company to save many thousands of pounds in energy costs.

Among the measures introduced by Elgin-based Highland Galvanizers was the replacement of its existing fixed speed compressor with a speed-regulated model from CompAir.

Highland Galvanizers provides hot dip galvanising services to a wide range of industries throughout Scotland.

As well as considering the requirements of ISO14001, the company was looking to achieve energy savings in its progress towards meeting its Climate Change Levy (CCL) commitments and to counter the effects on the business of escalating utility costs.

Among the energy efficiency measures undertaken was the upgrade of the compressed air system.

A survey of the system identified that the existing compressor was not fully loaded and spent a significant amount of time running off load.

CompAir distributor Scot Industrial Air examined the usage requirements and recommended replacement with a CompAir L45SR variable speed compressor.

The resulting installation was subsequently data logged and showed energy savings in the region of GBP 6000 per annum.

Highland Galvanizers' Managing Director Geoff Crowley says: "We were supported in our energy saving drive with advice from Action Energy and we implemented a number of measures that have resulted in electricity savings of over 197,000kWh per annum - cost savings in the order of GBP 12,200".

"The new compressor alone has contributed some 50% to those savings and we saw a payback on our investment in just 19 months".

"The measures have also enabled us to maintain our CCL discount of GBP 2000 a year".

With its existing compressor system, Highland Galvanizers found itself in the common situation of having a compressor designed to perform continuously at maximum output capacity, whereas this maximum capacity was only required at limited peak times.

In normal operation, the majority of conventional compressors operate at an average of 50 to 70% of their full capacity.

CompAir's LSR series of speed regulated compressors incorporates a variable speed switched reluctance drive system which matches power consumption to air demand.

The LSR series compressors are able to accurately maintain a set pressure while responding instantly to changes in air demand.

Maintaining air system pressure at an exact pre-set level eliminates the need to operate within pressure bands, further enhancing energy performance by reducing electrical and mechanical loads.

A further operational advantage for Highland Galvanizers, where demand on the site's power supply is particularly high, is the fact that the L45SR is able to start without any increase in power supply current above normal running levels.

This reduces stress on the site's power supply and eliminates peak current energy cost penalties.

Other benefits of the LSR series include ease of installation, minimum maintenance, low noise outputs and simple operator controls.

Having achieved such significant energy cost savings at its Elgin plant, the company has also been able to use the experience to introduce an efficient compressed air system at a new facility.

Crowley explains: "We formed a new company, Highland Colour Coaters, in 2002".

"This operation is situated in a state-of-the art galvanising and powder coating plant in Cumbernauld".

"Compressed air is critical to the operation of the plant and our experience at Elgin had already shown that by selecting a variable speed drive compressor we could ensure an energy efficient operation from the outset".

As at Elgin, the compressor of choice for Highland Colour Coaters was a CompAir L45SR.

A data log exercise carried out during normal operation has confirmed that its energy cost is just over GBP 8,000 a year lower than if they had chosen a fixed speed compressor.

Bobby Hodge, CompAir Regional Manager, adds: "As our manufacturing industry faces increased competition from overseas it is critical that energy costs are controlled, CompAir's range of energy efficient variable speed compressors are helping industry achieve these savings while at the same time reducing carbon emissions to help meet the UK targets set at Koyoto".