Longcliffe reduce energy costs with Gardner Denver compressor
Calcium carbonate supplier saves over £4,000 per annum with intelligent CompAir system
LONGCLIFFE Quarries, one of the UK’s leading suppliers of calcium carbonate, are achieving minimum annual energy savings of around £4,200 with a predicted return on investment of less than 12 months – thanks to a new Gardner Denver compressed-air system supplied by distributors Aircare Compressor Services Ltd.
The quarry operator is in the process of implementing a programme to reduce carbon and other greenhouse gas emissions and, therefore, continually analyzes the energy performance of all its plant and equipment.
The company’s existing compressors had been running continuously – five days a week for the past six years – providing air to feed the pneumatic circuits throughout the quarry. With in excess of 45,000 running hours on each machine, performance and reliability were becoming problematic, impacting on both energy and maintenance costs.
In addition, the machines had been installed without any compressed-air control, meaning that the two 45kW units were both running simultaneously and inefficiently in order to produce the target air pressure.
Longcliffe Quarries decided to explore alternative options as Mark Whittaker, works engineer, explained: ‘Our compressors are a vital component in our plant operations and if a machine fails it could result in costly downtime. We also have a round-the-clock demand for air, meaning that we need to consider carefully the machines’ energy performance and reliability.
‘Having worked with Aircare previously, we commissioned the company to conduct a comprehensive audit of our actual site air demands to ascertain whether it would be more cost-effective to refurbish our existing machines or replace them with a new compressed-air system.
‘The results confirmed that smaller, high-efficiency compressors from CompAir would offer the low cost of ownership that we required, with payback in as little as 12 months.’
Steve Flint, account manager at Aircare, explained how the new compressed-air system is set to achieve significant energy savings. ‘Using the CompAir airINSITE air auditing system, we monitored the air demand over a typical production period to identify system inefficiencies,’ he said. ‘Results from the audit indicated that the site’s air demand could be met with two, smaller 37kW units.
‘The majority of the time, the minimum air demand from generation fluctuates from 150 cubic feet per minute to 210 cubic feet per minute. This typically requires only one compressor, the CompAir L37RS speed-regulated unit, to deliver the required air output to meet the peaks and troughs in air demand.
However, during busy periods, demand from generation can peak at 410 cubic feet per minute. Using a bespoke-designed, base load selector control system, the fixed-speed L37 compressor is automatically brought on line to cope with the increased air requirement until demand decreases.
Heat recovery has since been proposed as the next energy-saving project. Up to 80% of the energy used to power a compressor is converted to heat, so Longcliffe Quarries can reclaim and reuse as much of this otherwise wasted energy as possible.
Using an automatic volume control damper (VCD), hot air radiated from the compressors is recirculated back into the compressor house during the winter months, helping to save on heating costs. This process is thermostatically controlled, so that during higher ambient temperatures, when heating is not required, the VCD valve will stop the ducting of hot air.
Aircare Compressor Services provide full preventative maintenance, with monthly service checks and 24h support as part of a comprehensive six-year maintenance package.
