Drives & Controls May 2022

40 n MOTORS May 2022 www.drivesncontrols.com IE5 PM motors boost efficiency of novel UK compressor A round 10% of all industrial electricity in Europe goes into powering compressors. An effective way to tackle the climate emergency would be to reduce this figure. A new design of positive displacement compressor from a British developer might help to achieve this. Positive displacement compressors are mechanical devices that increase the pressure of a gas by reducing its volume. Compressors are ubiquitous, powering a wide variety of processes and machines, as well as transferring and blowing things around factories – such as pasta, pharmaceuticals, cereals, plastics and even the granular absorbents used in nappies. In fact, compressed air is considered the fourth utility for manufacturing – along with water, gas and electricity. Compressors are found not only in industry. They have applications ranging from air suspension systems on buses, to heat pumps and even domestic refrigerators where they keep the fridge’s contents cold. Compressors are everywhere, and they consume a lot of energy – up to 55% of the energy used in some manufacturing processes, although around 17% is a more typical figure. However, the full potential of compressor technologies has yet to be realised. The first rotary compressor design can be traced back to a water pump invented by the Italian designer Ramelli in 1588. Despite being designed to pump water, its core design is used to this day in vane and rolling piston compressors, and in air-conditioning systems. Another machine originally designed as a water pump made from wood, was re- purposed as the lobe blower back in the 1860s. This made the Roots brothers wealthy and still the design at the heart of most low- pressure air compressors. Arguably, the last big development was the screw compressor – invented by the Swede Alf Lysholm in 1935, originally for a steam turbine. His design currently dominates the mid-pressure market. A Warwickshire company called Lontra decided it was time to transform the industrial compressor landscape. It realised that compressors need to get gas in efficiently, compress it without leakage, and then let it out again without too much loss. Lontra designed a machine inspired by the piston and cylinder found in combustion engines. Essentially, it wraps a cylinder around into a doughnut shape so that the two ends meet. The ends are separated by a rotating disc, allowing the piston to become a blade. This new geometry is protected by a raft of patents. Early testing, in the water industry, has demonstrated electricity savings of more than 21% compared to rival machines that blow air through wastewater and use bacteria to break down pollutants. This process alone accounts for 1% of all UK electricity usage. In the pneumatic conveying sector, a trial of a Lontra compressor to blow solids through pipes achieved savings of up to 34% against a leading competitor. Most compressors are powered by electric motors. Lontra’s LP2 blade compressor uses a specially designed IE5 permanent magnet electric motor, chosen not only for its high efficiency, but because it generates less heat in the rotor. It is liquid- cooled, resulting in steadier temperatures and reducing the likelihood of overheating. Lontra commissioned WEG to design the special constant-torque motor that powers the compressor. The hollow-shaft motor, rated at 80kW, 2,500rpm, achieves efficiencies of 97% across its entire speed range. The motor is shaft-mounted, reducing losses and increasing the efficiency of the compressor even further. Lontra’s compressor proves that these machines do not need to absorb huge amounts of energy. The new design has revolutionised the industry, setting the standard for others to follow. Lontra announced recently that it is building a £17m smart factory in South Yorkshire to manufacture energy-saving low-pressure air systems for use in food and pharmaceutical production, as well as water treatment and other applications around the world. The factory is being financed by a grant and loan package totalling more than £7m from the South Yorkshire Renewal Fund, with about £10m of private sector match funding being supplied by Lontra itself. n A UK company has developed a revolutionary compressor technology that is up to a third more efficient than traditional compressor designs. Marek Lukaszczyk, WEG’s marketing manager for Europe and the Middle East, explains how the compressor is using a specially developed IE5 permanent magnet motor. Lontra’s blade compressor is powered by a specially developed permanent magnet motor