Reducing energy usage is a significant issue for manufacturers who utilise compressed air. In fact, energy is estimated to account for 75% of the lifetime costs of compressed air systems.
Up to 30% of that energy is wasted, so there is plenty of scope for manufacturers to optimise their compressed air systems, improve their bottom lines, and reduce their carbon footprints.
Energy savings can be made by achieving an operating balance that takes into account the capabilities of the compressors, production targets, and cost minimisation.
Overall energy bills can be reduced by looking at the overall compressed air system. In order to optimise energy usage, it is necessary to consider the compressed air generation units as well as the distribution network.
The Airscan system
Atlas Copco Compressors Australia undertakes audits, reports, and recommendations. Any optimised final solution will take into account plant changes, changing demand for compressed air over time, and the strengths and limitations of the individual pieces of machinery and distribution systems.
The company’s Airscan tool works in two steps. First it logs and analyses all the relevant parameters - flow delivered, power consumption, pressure and quality required. This process is flexible. Customers can specify its depth and the amount they would like to spend on it.
Once logged, these figures are used to prepare a report, including a cost analysis, graphs, and recommendations for optimising the system and reducing energy use. Several possible strategies are put forward.
A typical completed audit may first reveal that there are a number of air leaks within the distribution system. Repairs would be recommended.
Further, it may reveal that the number of unloaded running hours is high and recommend a reduction in order to cut energy usage. And it may recommend fine-tuning of settings and so on.
The company’s ES Central controllers are also useful tools for those looking to minimise energy bills.
Reduction in overall working pressure reduces energy use. Each 1 bar (14.5 psi) reduction in working pressure results in 7% direct energy savings and a further 3% saving through leak reduction.
With Central controllers it is possible to link all compressors and dryers, lower overall pressure band, eliminate the need for higher working pressure and optimise the compressor mix.
Energy Recovery Systems
When air compressors are in operation energy is lost as radiation. It is possible to recover this rejected heat and re-use it in the production cycle.
Atlas Copco’s Energy Recovery systems are able to extract an amount of energy from the compressed air that is equivalent to the amount of energy that the electric motor uses.
The most common uses for the recovered energy include process heating, extra space heating, heating water or preheating boiler make-up water.