Air knive helps Corus to cut costs

Chard, UK - Corus has achieved significant cost savings through the installation of a blower-powered airknife  to remove surface moisture from steel strip as it exits a five-stand mill at its Trostre Works, Llanelli. The company had previously used compressed air delivered through 66 nozzles, which was expensive process and impacted on production quality.

The nozzles delivered 1748 scfm at 5Bar, which equated to more than 7HP/5kW per nozzle making a total in excess of 345kW with an annual running cost for a 48 week/year of around £75,000. By comparison, the Airknife system, supplied by Air Control Industries Ltd of  Chard, Somerset, uses just 60kW yet achieves more efficient moisture removal. Payback was achieved in just 21 weeks.

Moreover, whilst the compressed air supply was vulnerable to demands for other operations within the plant, resulting in inconsistent performance, the blower-powered air knives deliver the required air output - constantly. Air delivered by the Airknives also has the benefit of being heated by the blowers, as a result of air compression, making it a more effective drying agent.

The original compressed air moisture removal system was also vulnerable to contamination by oil and moisture, which could cause imperfections in the tinplate - problems that have been eliminated by the new air knive system as air is filtered at the inlets of both the enclosure and blower.

The air knife moisture removal system comprises a pair of stainless steel chevron-shaped aiknives covering a width of 1240mm fed at all times by four of the company’s 15kW EP10 blowers, which are housed in pairs in acoustic enclosures. Air from the blowers is delivered to the air knives, first via 200mm ducting and then by two 150mm ducts. The blowers are powered by inverter-controlled, high-efficiency EFF1 motors.

“Low-volume and applications which require low to medium-pressure are an inefficient use of compressed air”, said Paul Millett, senior development engineer at Corus. "In less than six months we have recouped our investment and quality has also improved through the reduction of imperfections caused by contamination during the moisture removal process.”