Magic Word „Energy Efficiency“ Comvac: energy efficiency through new technologies and heat recovery
Viewed in terms of energy cost of ownership over their entire service lives, compressors, air blowers and vacuum generators cost much more to run than they do to purchase and install. Which is why many manufacturers will be using this year’s Comvac, the leading trade fair for compressed air and vacuum technology, to highlight the energy efficiency of their systems.
Compressed air is used in a wide range of industrial processes and systems, including all kinds of automation and process engineering technologies, drying systems, transport and handling solutions for powdered goods, not to mention power tools, hoists and packing systems. The industrial sector is therefore constantly seeking ways of generating and supplying this energy carrier as efficiently as possible. There’s only so much they can save on air volume, compressed air quality and pressure bands before overall system reliability, quality and safety start to suffer, so the primary focus is on energy costs.
Heat Recovery — an Exciting Option
Even major compressor manufacturers like Boge acknowledge that generating compressed air is not per se the most efficient form of energy conversion because a sizeable percentage of the input energy (electricity) used to generate compressed air is converted into heat. The good news is that Boge and several other Comvac exhibitors are committed to ensuring that this heat does not go unused. They have developed heat recovery systems that can boost overall compressor system efficiency — the ratio of usable energy output to primary energy input — to as much as 95 percent.
According to Dieter Richter, CEO of Boge Anlagenbau, the latest water-cooled compressors come factory-ready for heat recovery systems. But there are also solutions on the market for retrofitting older compressors with heat recovery systems. Boge, for example, offers a solution named Duotherm, which it will be showcasing at Comvac. “In Hannover, we’ll be presenting an external heat exchanger that can be retrofitted to Boge and other brands of compressor,” Dieter Richter said.
The Duotherm system is available in five output classes for oil-injected screw compressors of all rated outputs from 7.5 to 110 kilowatts and is easy to install. The heat recovery unit’s heat exchanger can be used to couple the compressor’s oil circuit with, say, the user’s process water system. In this way, the waste heat given off by the compressor is captured and transferred for use elsewhere in the factory. This free energy is a major plus, especially in factories that use temperature-based processes. But even in settings where process heat is not required, the recovered heat can still be used for space heating and for pre-heating water for showers, washrooms and the like.
Hybrid Compressors That Combine Rotary Lobe and Screw Technologies
Over the past few years, Aerzener Maschinenfabrik has been rolling out its new Delta Hybrid technology, an innovation the company describes as the “world’s first rotary lobe compressor.” Each Delta Hybrid unit brings together rotary lobe blower and compressor technology to form a rotary lobe compressor that opens up completely new possibilities in overpressure and vacuum generation. The Delta Hybrid series currently has 14 models in the overpressure class, with the largest-sized units capable of delivering positive pressures of up to 1.5 bar. Aerzener plans to continually expand the series.