How the Swedish Dafgård food plant recovers 98% energy
As a result of installing a new oil-free compressed air plant with 98% energy recovery, the Dafgård Family has been able to make big energy savings and reduce costs and carbon dioxide emissions. The short payback period and increased capacity made the choice for Atlas Copco an easy one.
Screw compressors Oil-free compressors Food & Beverage Class 0 Compressor Technique Compressor Technique
Energy efficient expansion of production
Oil-free compressors for increased air quality
During 2010, Dafgård Family expanded its production by building a new bakery, where the company’s famous sourdough bread is baked. Anders Dafgård ,Technical Manager, Dafgård Family explains: “With the expansion of our production, our demand for compressed air increased. Our compressed air system at that time was not up to the task. For that reason, we contacted Atlas Copco to review the potential for a new and larger plant.” It became apparent that potential energy savings and an increase of the compressed air quality could be made by switching from oil-injected to oil-free compressed air. “We measured the current energy consumption, and began to discuss the oil-free air alternative, dew points, energy recovery, a new compressor room, LCC calculations, control systems for multiple compressors…” “The compressed air quality of the oil-free alternative with internal MD dryer, together with the short payback period, became the deciding factors for the choice of the new oil-free air compressor” says Klas Johansson, Sales Engineer at Atlas Copco.
When upgrading our production, we always strive to improve our energy use, which means that we always choose the most energy-efficient alternative. That was a major factor in the choice of the new air compressor.
More than 100.000 dollars of yearly energy cost-savings
Dafgård Family installed a ZR 160 VSD FF oil-free air compressor with variable speed drive, internal MD dryer and an ES8 control system for multiple compressors.
“We have decreased our energy costs by 700,000 SEK, which is approximately $ 106,000, per year and lowered our carbon dioxide emissions by 117 metric tons per year”, says Anders Dafgård.
Energy savings of 1100 MWh/year
Atlas Copco’s system for energy recovery enables the surplus energy to be used for heating. Dafgård Family recovers approximately 98% of the surplus energy, which is used for preheating diluted water for the production’s boilers.
“We have many processes in our production where we use direct acting steam. In order to use the energy recovered from the compressor, we have installed a heat exchanger which transfers the heat to the diluted water.”
“That wat we save approximately 1100 MWh/year. In addition to all this we have also gained drier compressed air with higher quality”, concludes Jan-Åke Karlsson, manager processing compressed air at Dafgård Family.