Food Engineering
Field Reports

Clean compressed air system is green, too

The last thing a processor needs is oil-contaminated food. Oil-free air compressors fill the bill while conserving energy.

May 6, 2014
Kolak Snack Foods Ltd. is a leading UK manufacturer of crisps (potato chips) and snacks. Its brands include Kolak Diamond Crisps and Snacks and Dylans Hand Cooked Crisps. At its London plant, the company manufactures a range of standard, crinkle-cut and low-fat crisps; extruded products; pellet-based snacks; prawn crackers; and mini poppadoms (crisp, disc-shaped Indian food), both as its own brands and private label products. 

Atlas Copco ZT 90 air compressors
Atlas Copco ZT 90 air compressors deliver clean compressed air without using oil and conserve energy at Kolak Snack Foods in London, UK. Source: Atlas Copco.

When Kolak experienced a business upturn and required increased output capacity at its manufacturing plant in London, it decided to upgrade its production equipment, including its air compressors. Kolak chose oil-free air compressors from Atlas Copco due to their reliability and ability to provide a guaranteed supply of high-quality, oil-free air.

Clean, oil-free compressed air and energy efficiency were essential considerations in the selection of new air compressors when upgrading the existing plant air facility. Kolak is committed to quality, and so, while ensuring reliability and the continuity of output, the company also wanted to be certain any possible risk of product contamination during process operations was eliminated.

To achieve this, Kolak chose Atlas Copco oil-free, rotary screw, full-feature machines—two ZT 90 FF compressors and a ZT 90 VSD (variable speed drive) FF—which provide a guaranteed supply of high-quality air. As a result of the installation, the process air at Kolak’s London plant complies with the ISO 8573-1 (2010) Class 0 standard of air purity, which embraces the Class 0 industry standard. Class 0 measures all three forms of oil contamination: aerosol, vapor and liquid. Atlas Copco is said to be the first compressor manufacturer in the world to achieve the TÜV-certified standard for its zero-oil, zero-risk Z-series of stationary compressors.

The 24/7 work pattern at the London plant, which is in place to meet production demand, meant the new compressors had to be able to work long hours. “The Atlas Copco VSD compressor works in tandem with the base load compressors to cover all the main 7 bar [101.5psi] plant air application duties, including heat exchanger, steam boiler and packing operations,” says Rikin Lakhani, Kolak Snack Foods director. “This ensures output is matched to demand in the most energy-efficient way, with the VSD compressor taking over any additional site load.”

Each of the three new compressors features a total installation concept—a pre-wired and pre-piped solution, ready for use out of the box. Integrating each compressor’s internally mounted dryer and variable speed drive enables the compact package to supply high-quality dry compressed air at the lowest cost. 

The internally mounted adsorption dryer eliminates the moisture before it enters the air net to provide a reliable process and contamination-free end product. No external energy is needed to dry the air, and as the dryer needs no purge air, no compressed air is wasted. The pressure drop through the dryer is minimal, which again cuts down its operating cost. 


For more information:  Holly Boutot, 413-493-7116,
holly.boutot@us.atlascopco.com, www.atlascopco.com