The headquarters of Steve Lindsey’s innovative compressor company, Lontra, is in the picturesque village of Napton on the Hill in the heart of the Warwickshire countryside. While it is probably the last place you’d expect to find a state-of-the-art technology centre, it fits the company’s ethos: setting itself apart in a traditional industry by blending good old-fashioned engineering with the latest in manufacturing and design techniques.
Founded in 2004, the company claims the novel Blade Compressor design, which has delivered energy savings of more than 20% in commercial operations such as wastewater aeration and industrial air, is “the first big change in the air compressor industry since the 1800s”. Hailed by some as the next James Dyson, Lindsey has reinvented the air compressor to overcome common problems such as air leakage and inefficient air compression that lead to higher energy usage and the need to use environmentally unfriendly oil.
Lontra’s Blade Compressor is oil-free and double-acting: continuously taking air in and compressing it at the same time. The design can be imagined as a piston and a cylinder – but the cylinder is wrapped into a doughnut-shaped ring and the piston is a blade. The compressor features an intake port that is constantly open, without valves. As the blade rotates, it pulls a volume of air behind it until it reaches its original starting point. The blade passes through a disc and releases the compressed air into a chamber.
The oil-free geometry provides internal compression with very low leakage and low inlet and outlet flow losses, and is also claimed to be quieter, smoother and more efficient than a lot of traditional compressors on the market. So just how important is such a development?
Lindsey stresses that compressors are proliferating globally, not just in factories but in trains and even in fridges. “They underlie all of modern life,” he says. Sometimes described as ‘the fifth utility’, compressors account for 10% of industrial electricity use in Europe.
For example, “1% of the UK’s electricity is used on wastewater treatment, dominated by compressed air”, he says. In this sector, his device is already proving its usefulness. “The Lontra Blade Compressor has demonstrated 21% electricity saving in its first application in the water industry at a Worcester waste treatment facility owned by Severn Trent Water,” he says. In addition, the company has licensed its product to Sulzer, a Swiss engineering group, for use in the municipal and regulated wastewater treatment sector, and the firm has reported reaching even higher energy savings than those achieved in Worcester.
However, Lontra is setting its sights on more than just wastewater treatment. “Wastewater is only a small part,” says Lindsey. “The food industry uses compressed air to blow food around factories and into packets, corn is blown out of a hopper and around a factory, cement is transported around sites via compressed air. It is such a big industry, and a small change will make a big difference to the world’s energy consumption.”
The company’s new medium-pressure, 7-10bar Blade Compressor will compete in a market worth $30 billion. In addition, its original model offers lower pressures of up to 1bar. “We now have one for low- and medium-pressure factory use, to compete in markets with a total value of $60 billion,” says Lindsey.
Lontra is still rapidly expanding. The company has doubled in size every 14 months, and this growth shows no signs of slowing. This expansion has included the launch of a technology centre, which boasts an array of high-tech kit to ensure the company’s design process stays ahead of the game.
The centre’s test cell can operate two compressors side-by-side and runs 93 data channels simultaneously, measuring conditions such as temperature, air flow, movement and pressure at 25kHz. “If running at, say, 4,000rpm, you can freeze-frame the machine at every degree and match with models. It allows you to develop the product much more quickly,” says Lindsey.The test cell provides thermal imagery and has a host of cameras running 24/7. The data generated by the instrumentation of the rig is fed to Lontra’s eight-strong design team to create an almost realtime loop for rapid development. The rig was used to create the medium-pressure, 10bar Blade Compressor.
The design team has also developed an analytical model of the Blade Compressor to run a virtual prototype and virtual tests of the blade in the various conditions it will face in industry – an unusual approach for this sector. “This kind of thing is found in high-end automotive but not in the compressor industry,” says Lindsey.
Clive Hudson, engineering director at Lontra, agrees. “In this industry, people have not had this much data,” he says. “It is a modern way of looking at a traditional industry.”
Lontra may be grabbing headlines with its oil-free, energy-saving design, but it is not the only company to be pushing forward compressor technology to achieve higher levels of efficiency.
Another innovator in the field is Atlas Copco. “A recent milestone was the launch of the GA VSD+ compressor range in 2013, which saw breakthroughs in the design, size, noise emissions and energy savings of oil-injected compressors,” says the company.
Atlas Copco claims the 7-15kW GA VSD+ is the biggest innovation in small compressor technology in 20 years, providing users with energy savings of up to 50% compared with traditional, fixed-speed compressors. It is 15% more efficient than the company’s current variable-speed drive compressor (the 7-37kW GA VSD), and also provides a leap in free air delivery – the amount of air flow you get from the compressor in standard conditions – of 12%.
Magnetic motors
Initially available in 7-15kW options, the range was recently extended with models between 18 and 37kW. Atlas Copco also began manufacturing its own inverter in 2014, the Neos, made to suit the often tough and dusty working conditions of a compressor.
The improvement in energy efficiency is made possible by the company’s interior permanent magnetic (iPM) motors, which drive the new compressor range – this is the first time it has manufactured motors for compressors.
The vertically mounted, IP66, oil-cooled iPM motor was specifically designed by Atlas Copco to match its screw element, and is fully enclosed to improve reliability. The use of the company’s own direct-drive motors means that the latest compressor outperforms comparable fixed-speed models even at full load, it claims.
Atlas Copco redesigned the conventional layout of a compressor. Instead of a space-hogging horizontal design, the new compressor has a vertical layout that provides a canopy size 55% smaller than traditional models. This small footprint (610 x 630mm) allows the compressor to be placed right on the production line. Since only two panels need to be removed for servicing, it can even be placed against a wall.
In addition, the compressor runs more quietly than previous models, at 62dB(A), because of the integration of an ERP 2015-compliant efficient fan motor that reduces electricity consumption and noise levels. The low noise levels are further aided by the use of separate compartments for the drivetrain and cooling system.
Paul Clark, business line manager for the industrial air division of Atlas Copco Compressors, says: “With products of this standard coming in, there is every reason to be confident that, in the near future, every new compressor will incorporate variable-speed drive.”
Ingersoll Rand is also making advances with compressors. Kevin Kosobud, portfolio leader for the company’s contact-cooled compressors, says that a lot of the change in the industry is being driven by customers looking to reduce their energy use following the setting of new climate targets. The industry is also facing pressure from legislation from the EU and US Department of Energy to make compressors much more efficient than ever before.
“About a couple of years ago, we embarked on looking at our oil-flooded compressors, and developing new air-ends (the compressor screw element) and new packages to be able to exceed all of these needs from the customers and the regulations,” says Kosobud.
This process has led to the development of Ingersoll Rand’s next-generation R-Series line of oil-flooded rotary screw compressors, which was launched six months ago. The air-end enhancements feature an optimised rotor profile that can deliver up to 18% energy efficiency.
The R-Series has been analytically modelled for low pressure drop, and has minimal sound output. It also features an intelligent progressive adaptive control, which displays vital information, such as lubricant levels, measured by onboard sensors. “For example, if more lubricant is required it will interface with you and notify you and your system when maintenance needs to be done, so users can effectively manage maintenance and reduce downtime when the plant is in full utilisation mode,” says Kosobud.
The total air system option includes an integrated refrigerated dryer, patented three-in-one heat exchanger and coalescing filters to ensure the compressor operates reliably in a hot, dusty, industrial environment.
Developing the R-Series has been a big engineering project for Ingersoll Rand, particularly as some of the company’s legacy products were designed well over 10 years ago. “If you think about what has happened in efficiency requirements from an end-user standpoint, and then what has happened from a technology standpoint, achieving efficiency requirements and the way you design a new air-end are a lot more sophisticated, including the kind of software models that we’ve been able to use,” says Kosobud.
To allow it to develop products as quickly as possible, Ingersoll Rand has design teams based in North Carolina, Shanghai, the Czech Republic and India. The teams work collaboratively. When one finishes working on a design for a product, the next team will pick it up and continue to refine it.
In an attempt to outpace targets for energy efficiency in the industry, Ingersoll Rand will be launching a 37kW variable-speed unit in the R-Series line on 1 September. Kosobud says this model will surpass the mandate for Lot 31, the EU’s eco-design preparatory study on compressors.
“It’s exciting, as it will deliver energy savings to the customers that they have been asking from us for a long time, and will see them make substantial savings.
“In response to customers we have also made sure that the compressors are as reliable as possible as uptime is so important.”
For example, in a measure to improve reliability, steel graded hoses, rather than rubber ones, are now used inside the compressor package. While the material costs more, steel ensures there will be no leakage. This feature will be used throughout Ingersoll Rand’s future lines.
The company is also providing its customers with a dedicated team that will look for “energy waste points” throughout an entire air system in a manufacturing facility to improve the energy efficiency of the whole system, not just the compressor.
“With the platforms that we’ve developed, we can react to new legislation in the future, new user needs and be able to refresh this product, because we are building this programme from more of a platform perspective,” says Kosobud.
It seems, then, that an invention underpinning much of modern life, but with its roots firmly in the 18th century, is finally being given a high-tech, 21st-century makeover, driven by the modern concerns about global warming and the pressing need to reduce energy consumption.
In focus: Energy-saving potential
“The Lontra Blade Compressor has demonstrated 21% electricity saving in its first application in the water industry at a Worcester waste treatment facility owned by Severn Trent Water.”
“The food industry uses compressed air to blow food around factories and into packets, corn is blown out of a hopper and around a factory, cement is transported around sites via compressed air. It is such a big industry, and a small change will make a big difference to the world’s energy consumption.”