A technical white paper published by Atlas Copco's Oil-free Air Division, explaining the differences between screw technology and the traditional Roots-type lobe technology, concludes that the introduction of air blowers using internal compression instead of external compression sets a new standard for energy efficiency in the low-pressure market.
On average, screw technology is reported to be 30 per cent more energy-efficient - and this is the technology used in Atlas Copco's recently introduced ZS range of blowers that improve energy efficiency for low-pressure applications and in industries such as wastewater treatment and pneumatic conveying.
Chris Lybaert, President of Atlas Copco's Oil-free Air Division, states: "Over the past 50 years the blower market for small-volume flows has not seen any major technical improvements. The only considerable development we have seen with the Roots-type lobe blowers was the reduction of pulsation levels. There were still significant steps to be made in the area of energy efficiency. Atlas Copco achieved this by developing the twin-screw design for a low-pressure blower. By doing so, we introduced a technological advantage in this market segment."
The range of ZS screw blowers uses the concept of internal compression, while the traditional Roots-type lobe blowers rely on external compression to obtain an external system pressure. The detailed technical white paper demonstrates that, with a thermodynamic approach, internal compression is more efficient than external compression from 0.4bar(e) / 5.8psi(g) upwards. Tests, witnessed and certified by the independent Technische Uberwachungs-Verein (German Technical Monitoring Association, or TUV) have proven that the ZS is 23.8 per cent more energy-efficient than a tri-lobe blower at 0.5bar(e)/7psig, and 39.7 per cent at 0.9bar(e)/13psig. The technical white paper, TUV certificate and additional information, images and movies can be found at www.efficiencyblowers.com/.