Save energy, save money – simple credit crunch proof economics
February 15th 2009 The prevailing climate of financial uncertainty within commerce and industry and fluctuating fuel prices makes it essential for manufacturing and process industries to contain and control their consumables and energy costs. Here John Forman of Atlas Copco Compressors examines the issues.
Minimising the use of energy is a primary focus area for all companies and Atlas Copco is no different, evidenced by the increase in the number of specifically energy-efficient products it supplies. This continuous shift towards more energy-efficient equipment and services has resulted in reduced energy consumption throughout a large number of installations within industry.
As the world leader in compressed air technology, Atlas Copco is recognised as a solutions provider that not only innovates state-of-the-art products, services and systems but assists compressed air users to take all necessary steps to measure, control and, where possible, to reduce their energy consumption.
For example, the company stresses the importance of the correct sizing of a compressor installation to meet a specific production requirement. The nominal compressed air requirement of a system is determined by all of the consumers – the tools, machines and processes. Therefore the size of a compressor should be based not on the total air-using equipment but on the usage factor at any given time. Equally important, there is a need to conduct regular system audits to provide a true picture of how much energy is being used and to highlight any sources of avoidable losses within a network.
These are just some of vital measures that help the user avoid the wasted money of inefficient compressed air production.
Checking for peak efficiency
While it is obvious that a compressed air system operating at peak efficiency saves money, not every operator is aware of just how fit their installation may be – and with energy costs expected to keep rising there has never been a better time to find out. That is why, as part its commitment to keeping energy and production costs down to the minimum, Atlas Copco offers operators throughout industry a free compressed air system health check.
The procedure is a non-intrusive service that doesn’t interfere with production processes and examines the entire air supply system - compressors, filters, dryers, pipework, ancillaries, controls and monitoring - highlighting every energy-consuming feature.
The detailed examination starts with an assessment of the size and capacity of the compressor installation and its running profile relative to the compressed air application. That means noting the hours it is loaded/unloaded or the operating hours that are actually timed during the examination visit. Running pressure is also checked to ensure that it is at a level appropriate to the demands of downstream processes, as excessive downturn of the delivered air pressure can waste energy.
But, without doubt, one of the largest energy-loss culprits that the experts will focus upon has to be the condition and configuration of the airnet pipe work. Here even the smallest leaks can create significant pressure drops and can represent more than 75% of the running costs during the working life of a compressed air installation, so this particular aspect of a system merits special attention.
Once the examining engineer has completed all aspects of the assessment process, an on the spot written assessment is provided that shows exactly where matters can be improved and essential savings can be made.
Energy saving concepts
Many of the true energy economies of the present and the future start with the design of the compressed air products and systems themselves. Companies these days must adopt a design philosophy that from the outset places maximum emphasis on gearing technology developments towards energy-saving product and system solutions.
As an example of this approach, and not the least of Atlas Copco’s achievements, was the pioneering introduction of integrated variable speed drives to its range of oil-injected and oil-free stationary compressors - an innovation that offers the benefit of matching output to process demand which can save up to 35% of energy costs.
The pursuit of ever-greater energy efficiency is also embodied in the latest introductions to the GA compressor family. In fact, these are the world’s first oil-injected compressors to integrate a water separator into the compressed air cooling system, thereby reducing internal pressure drops by 50% and contributing an extra 2% to overall energy efficiency. What’s more, these air compressors also offer VSD-controlled radial cooling fans for even greater economy, capable of reducing energy requirements by up to a massive 50%.
One new version of these stationary screw compressors, with variable speed drive, has broken eight performance records within the compressed air industry in terms of overall energy requirements, energy consumption of individual elements and the lifetime of replacement parts.
Engine regulation system for portable compressors
And it is not only stationary compressors that are designed for optimal energy-saving performance. In calculating the total cost of ownership for a portable compressor, the largest portion of expense is operating cost - and up to 80% of that cost is for fuel. So every saving in the amount of fuel consumed by a portable compressor has a direct positive impact on the operator’s bottom line.
Conventional engine regulation systems for portable compressors focus on stable output but not on optimised fuel consumption at varying loads. The electronic control module of the unique FuelXpertTM system matches the air demand needs to the engine speed and air inlet to ensure that fuel consumption is minimal regardless of workload and operating conditions achieving a fuel saving of 10%.
Nitrogen generation at the lowest cost
Energy-saving innovations are not confined to the production of compressed air alone. Low tyre pressure is a major contributor to tyre wear, to inferior braking/handling performance, and to excessive fuel consumption – a direct energy cost. The culprit is the gradual migration of oxygen through the tyre walls that leads to progressive under inflation. What’s more, minute rust particles in the wheel wells, created partly from moisture-laden inflation air, find their way into valve cores, prevent correct seating and lead to slow, undetected leaks.
Nitrogen provides the answer to all of these problems. Nitrogen is dry and contains no moisture. Its inert nature prevents rust formation and, without oxygen and moisture present, there is little possibility of the tyre aging prematurely through chemical oxidation. The result is likely to be a more fuel efficient and safe tyre performance with the added bonus of tangible savings of up to 4% in terms of fuel consumption and an estimated 20% in tyre replacement costs. This can lead to a significant saving if you think about haulage vehicles, delivery vans, company cars, materials handling equipment etc etc.
Atlas Copco was also the first company to introduce dual output compressors, such as the innovative GN range, bringing nitrogen and compressed air simultaneously to the automotive workplace. The dual output unit can deliver high quality compressed air for workshop requirements and consistent 97% purity nitrogen for the tyre inflation demands of a wide of range of vehicles.
Regular maintenance reduces running costs
The simplest way to save money from all types of compressor equipment and systems is a programme of regular maintenance. This not only keeps the production facility operating at top efficiency, but it is also an opportunity to reduce running costs.
Around 10% of the lifetime cost of an air compressor is spent on maintenance (around 80% is for electrical power). Which is why planned maintenance packages, designed to maximise the productivity and work life of the compressor are an economic necessity.
The credit crunch and all that it has brought with it has not changed some simple economic truths one iota. If you save energy you save money has always been a true statement. However, the crunch has, alongside a spike in energy prices, focused our collective minds on eliminating the most glaring of inefficiencies and the compressed air system is as good as place to start as any.
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