Emerald Group Publishing Limited
Copyright © 2000, MCB UP Limited
HPC compressors cut computer manufacturer's costs
Edited by Jenny Pickles,New Developments Section Editor
HPC compressors cut computer manufacturer's costs
Keywords Computers, Operating costs, Energy saving
A major Taiwanese-owned computer manufacturer, Foxteq of Renfrew, is achieving major energy savings with three HPC Plusair direct-coupled rotary screw compressors. After the Greenfield site factory opened in summer 1998, output of PCs for IBM and Compaq increased dramatically to around 100,000 units per year within weeks, yet the costs of Foxteq's compressed air remains reassuringly low.
"It's not just the energy savings - the quality of the compressed air is so good" said Robin Sinclair, Maintenance Supervisor at Foxteq. "Clean air is very important to us, particularly for our powder coating line. Any dampness or oil in the compressed air causes a blotchy finish - and that's an instant reject. We have had no problems at all."
Foxteq manufactures PCs from start to finish, with a pressing shop manufacturing computer chassis, an injection moulding shop producing the enclosures, the powder coating line spraying the colour finishes and a large cleanroom assembly area. Some 250 people are employed at the Renfrew site.
Facilities and Maintenance Manager John McBlain and Maintenance Supervisor Robin Sinclair had both had excellent experience of HPC screw compressor installations in other locations, so were keen to include HPC in the list of possible suppliers when the factory was planned in 1998.
"At my last company we had two new compressors and one old HPC Plusair" said Robin Sinclair. "Only the HPC machine was reliable".
John McBlain asked several compressor suppliers to quote, including Kerr Compressor Engineers, the HPC Authorised Distributor for Scotland, based in East Kilbride. He asked each to recommend a compressed air installation capable of delivering up to 1,430cfm (40.5m3/min) of clean, dry compressed air at 7.5bar and at minimum cost. The free air delivery figure was calculated to allow for expected growth at Foxteq and for compressed air provision during routine maintenance.
The cost of running was vital to Foxteq calculations, since the company has a set budgeted running cost for each of their factories throughout the world, which makes it possible to define exactly how much it costs to make each component. Kerr Compressor Engineers therefore proposed installing the latest HPC Plusair direct-coupled screw compressors, which in some applications have lower running and long-term maintenance costs than alternative screw compressor designs. In these HPC DSD units, the drive motor and the airend are designed to operate at the same low speed, making it possible for the drive and compression units to be directly coupled with no transmission losses, which cuts wear and also reduces noise and vibration. The low noise level of the DSD compressors was also important because the compressors were to be installed within the working area.
With the quotation for the compressor installation, Ian Kerr, the Managing Director of Kerr Compressor Engineers, supplied detailed power consumption data for HPC Plusair DSD screw compressors plus forward projections for a maintenance contract. Comparing these with other suppliers' figures, John McBlain and his team decided that the HPC system, while not the cheapest at the outset, would provide both the highest quality compressed air and the lowest total cost over a projected five years' operation.
Foxteq took over its new premises at the beginning of May 1998, ordered their compressor installation later that month and took delivery in June, two weeks after the order was placed. Commissioned during July 1998, the installation consists of three HPC Plusair DSD141 direct-coupled rotary screw compressors, an HPC MAC41 digital sequencer, a large compressed air dryer and filters to remove all oil and particulate. Each DSD141 is capable of delivering 476cfm (13.5m3/min) of compressed air and the current configuration is to have two compressors on line at any one time with the third on standby. Ian Kerr makes the point that there is a big difference between the geared coupling which some compressor manufacturers refer to as "direct drive" and true direct coupling, in which there are no gearing, fewer components and greater efficiency. The lack of gearing dramatically reduces the vibration factor, and he stood a 20p piece on its edge on the top of one of the compressors while it was working to demonstrate just how little vibration is produced. The 20p piece stayed upright until he removed it. Less vibration means less noise and ultimately less wear, again improving the value of the direct-coupled compressors.
"In average factory conditions, you can't even tell by listening whether or not an HPC DSD compressor is running" he said. "You have to put your hand on it to be sure". The Foxteq compressor installation has proved to be totally reliable since its installation.
"The compressor installation is one of the areas of the factory we never have to bother about" said Robin Sinclair. "We just leave running the system to the MAC-41 controller. There are not many systems in the factory which are that reliable!"
John McBlain is enthusiastic about the standard of engineering and support his company has received from Kerr Compressor Engineers. "Their support is first-class and their professionalism, engineering standards and design capability to give us the air quality we need cannot be bettered" he said. "This is the sort of package I have dreamed about."
For further information from: Mark Sharman, HPC Engineering Plc, Victoria Gardens, Burgess Hill, West Sussex RH15 9RQ. Tel: +44 (0) 1444 241671; Fax: +44 (0) 1444 247304.