Manufacturing facility slashes pressure - and power bills

Optimising on-site compressed air

A recent energy audit at its manufacturing facility paves the way for Geofabrics to optimise its on-site compressed air system and derive ongoing energy savings.

For the past 23 years, Geofabrics has manufactured a range of innovative geosynthetic solutions - such as ‘spunbond’ non-woven continuous filament needle-punched geotextiles - from its headquarters in North Albury near the Victoria/New South Wales border. The manufacturing process is highly reliant on compressed air - clean and dry compressed air at constant pressure is vital to the success of the fibre-drawing process. In fact, compressed air generation accounts for approximately two thirds of the site’s electricity consumption.

Recently, Geofabrics carried out a site energy audit, confirming the company’s suspicions that its manufacturing process had become somewhat energy intensive. As a result, the company executed a plant-wide overhaul of its manufacturing process. Central to the overhaul was the upgrade of the site’s compressed air system. Here, Geofabrics implemented a customised compressed air solution from Champion Compressors.

According to Geofabrics Operations Manager Rod Press, it is essential that the process air pressure is maintained at exactly 3.2 bar. “We can’t use higher pressure air as it causes the geosynthetic fibre to rip. Conversely, if the pressure is too low, the fibre will block the tubes of the manufacturing line,” he says. “We need precise control over the air to ensure we have access to it at 3.2 bar - and lots of it. This is the optimum pressure at which the fibre can be drawn to maintain its structural integrity, while at the same time optimising the production rate.”

Prior to the upgrade, a control valve was used to drop the compressed air pressure down from 7 to 3.2 bar. This was obviously an area of inefficiency in the old production process, but a low-pressure compressor that met all of the criteria had always proved difficult to come by.

Following the energy audit, Geofabrics engaged local automation and process-control specialist Remtron Automation to develop a solution designed to reduce power consumption. Together, the Champion Compressors/Remtron team was able to custom-design a low-pressure compressor with the ability to deliver compressed air at only 4 bar.

“Other compressor manufacturers could only offer off-the-shelf models incapable of meeting our operational requirements,” says Press. “We decided to go with the Champion solution as they had the ability to tailor the unit to our requirements.”

The customised Champion 160 kW VOC160 variable output compressor (VOC) is complemented by a suite of Champion’s ancillary air-treatment equipment, including a refrigerated air-dryer and a filtering system designed to remove contaminants down to 0.01 microns.

After one year in operation, the low-pressure air compressor has had a dramatic impact on Geofabrics’ bottom line, with the company reducing its power consumption by a staggering 12%. “The compressor has just about paid for itself after only a year,” says Press.

At present, the new low-pressure unit handles the majority of the process air production. When additional air is required, one of the legacy 7 bar compressors kicks in and provides the required top-up. This small remaining inefficiency is set to be remedied with the imminent delivery of a second low-pressure Champion compressor.

With a strong likelihood for further energy savings, the future looks bright for Geofabrics. In fact, once installed, the second low-pressure compressor will provide the company with the capacity to increase production. “We now have a major part of the infrastructure in place to boost throughput should we require,” says Press. “With support from Remtron and Champion Compressors, we’ve been able to take our manufacturing process to the next level, safe in the knowledge that that our energy savings will also continue to increase.”