Compressors that impress
Choosing the right compressor is not a hit and miss affair. Many factors need to be considered as Greg Davie, marketing manager of GnG Sales explains.
THE HUMBLE AIR COMPRESSOR is the lifeblood of every panel shop. Down time or inefficient running of this workhorse will lead to delays and a significant impact in the shop’s profitability. Proper maintenance of this most
valuable piece of equipment is critical, but selecting the right one to begin with can help minimise future problems. There is a bit to consider when replacing an old compressor or opening a new facility. You need to carefully
weigh up three major factors: current requirements; future shop expansion; budget.
ESTIMATING YOUR CURRENT AND FUTURE NEEDS
When selecting the right size compressor you need to accurately calculate current needs and estimate forecasted expansion of workload within the compressor’s lifecycle. The service life of the compressor will vary depending
upon the type and quality you choose. Your compressor dealer will help you.
To estimate current and future needs it is necessary to find out actual air consumption of equipment required to run off the compressor.
The supplier of your air tools can help you with information. A word of warning - make sure you get the “Actual” air consumption and not the “Average”. There is a significant difference in these numbers and if you base your requirements on the “Average” figures you will find you have underestimated your requirements by as much as 50 per cent. Once you have, as accurately as possible, identified your current and future needs add a factor of 30 per cent to this figure. Doing this will ensure the compressor is never overworked when under maximum expected load. This will result in a longer service life and lower maintenance cost. This additional factor of 30 per cent will allow the compressor
to cycle, which dramatically aids in the cooling process of the pump and minimises oil bypass through the piston ring into the air line. It will also minimise the heat generated from the compressor and reduce moisture contamination.
CHOOSING THE RIGHT COMPRESSOR TYPE
Once the size of the compressor is determined a decision can be made, based on efficiency and budget, as to what compressor type to install.
Most workshops need three-phase power to drive a suitable compressor. Compressor sizes from about 20 to 30 cfm are normally standard piston powered, however a screw compressor is most likely be the best option for larger output.
A standard piston compressor is normally powered by a motor connected to the pump via V belts. The pump can consist of one, two or three cylinders that compress air and store it in a receiver tank. This system can be quite noisy and a suitable position, in a dust-free environment, should be found. Sound insulated cages are available to minimise noise pollution.
BUDGET PERMITTING
The more practical choice for larger air requirements is a screw compressor. The most common size for the average panel shop would be an 11kW (15HP) unit supplying approx 58cfm free air delivery. Screw compressors are
extremely quiet and offer longer service life provided there are standard prescribed maintenance schedules. Like piston types, screw compressors are supplied with a suitable storage receiver. Regardless of compressor types it is highly recommended that quality refrigerated drier systems and pre-filters and after-filters are installed to eliminate contamination in air lines.
It will cost you a little more at installation but will pay dividends by reducing wear and tear on air tools and contamination of job areas.
GET HELP
You need a competent air line designer and installer to make sure you get the best from your compressor. Many panel shops have poorly designed and installed air line systems which choke air supply to workstations and contaminate tools with oil, dust and moisture.
By ensuring you identify the right layout of the air line, every part of the workshop can benefit from clean, regulated air supply so critical to the performance and life of the equipment used in the air line and to shop profitability.