Shows spotlight clean, efficient power

Tom Shelley reports on developments in fluid power

Saving energy and protecting the environment were the two key trends in hydraulic and pneumatic developments at this year's IFPEX – Air-Tech show. By the entrance was a stand devoted to Exhaust Air Recycling System or EARS, which was invented by Australian Chris Bosua and which reduces energy consumption by recycling partly compressed exhaust air instead of venting it to atmosphere. Asked whether it was finding applications, Bosua replied, "In the rest of the world, yes, but in the UK, rather less so." While small systems cut energy costs (Bosua estimates that a 7.5kW system would only consume £2,100 worth of energy costs in a year as opposed to £4,000 using a conventional system) a larger system could additionally allow the purchase of a smaller compressor, so payback time could be "a couple of months." Presently, the only significant commercial customer identified in the UK is Kingpin Tyres, a remould company in Wem, Shropshire, but Tom Parker Ltd has recently purchased the UK distribution rights. Less radical, but equally effective in installations with multiple air compressors is the Belgian-developed system marketed in the UK by EnergAir Solutions. UK manager Pete Tomlins explained that 20 to 30% savings are not uncommon when a single controller is used to switch individual fixed-speed compressors on a joint system in and out of service and to regulate the speed of one or more compressors powered through variable speed drives. System setup begins by monitoring electric current being consumed by each compressor and pressure delivered, after which an audit shows how much energy is being wasted. A system strategy can then implemented in which the minimum number of fixed speed compressors are kept in service. The other common feature in many of the offerings to be found at the shows was environmental concern. Peter Stanford of Bambi Air Compressors showed us some of its totally enclosed 'silent' air compressors, most of which produce no more than 40dB(A) of noise. Typical applications include supplying compressed air to open doors in residential homes or t-shirt printing in high street shops. The company also supplies oil-free compressors that are slightly noisier, typically producing 53dB(A). Applications include supplying air to pneumatically-actuated valves in landfill gas systems and water treatment plants. Several companies had new oil water separators to allow cleaned condensate to be discharged without incurring penalties for discharging water containing oil. Ken Fitzsimmonds of Filterworld showed us the company's new, British-made 'Magnasorb' separators that remove oil by passing condensed water through a convoluted path. Oil remains in the filter cartridge in the canister. When it is full, it is disposed of. Since the water is flowing, there is no stagnant water in the devices to harbour bacteria, unlike some other designs. The absorbing media used are a primary, porous, polymer-based material that absorbs oil but rejects water, and an active, carbon-based secondary element. Close by was another company, Condensate Systems, which claimed to offer what company managing director Richard Turner described as "the lowest-priced condensate cleaner on the market". British designed and made, Sepura's 'SEP 60' features a patented oil adsorption medium based on recycled glass, which is claimed to be up to three times as effective as active carbon. Designed for system capacities of up to 60cfm = 10kW, where it has a service life of 5000 operating hours or up to one year, it brings legal compliance within economical reach of many thousands of smaller compressor users. In the field of hydraulics, Mike Retford, sales and engineering director of MGR Fluid Power claimed that "water is coming back into vogue again" as an alternative working fluid to oil. Water was, of course, the original working fluid used in hydraulic systems, and has gained particularity popularity in the oil and gas industries or anywhere where there is a great risk of fire, such as in the high temperature forging presses used in the aerospace industries. Water is much more erosive than oil, but Retford pointed out that new hard coatings developed by the US company BOC Water Hydraulics have overcome many of the problems, and the rising price of hydraulic oil is causing renewed interest in water.