Hitachi demonstrates that energy efficiency has powerful financial rewards.
While South Africa may currently be experiencing an intense lesson in the need for energy efficiency and power saving, globally companies are becoming increasingly aware of energy costs; and have undertaken initiatives to reduce energy usage and attendant costs, as well as to protect the environment.
This is according to Mike Cronin, owner and managing director of Elquip Solutions, the Hitachi Drives agency in South Africa.
“Because of our links to Hitachi worldwide, we have the advantage of being exposed to some of their best practices; and of bringing South African industry the benefit of this experience,” explains Cronin.
“One case study that immediately caught our eye because of the pervasive South African energy crisis at present, was a project undertaken at the end of 2007 by Hitachi for Stryker Orthopaedics; which manufactures a range of orthopaedic implants, bone cements and bone substitute materials at its facility in Limerick, Ireland.”
Design considerations
Cronin continues: “According to Silverteam, a UK-based drives and automation company, which also specialises in Hitachi solutions, Stryker’s plant has eight extraction fans, and all were working hard to ensure complete extraction of dust particles. Initial calculations suggested that significant energy savings could be made if each were tuned to exact local demand, instead of operating faster than necessary.”
There were a number of practical issues to be addressed, not least, which would prove the best drives to use. Ultimately, the L300P Series from Hitachi were recommended. The drives are particularly appropriate for fan drive applications with a track record in energy-saving applications.
A PLC would be required to control the system and Silverteam selected a unit from the Hitachi EH150 series for the purpose. The PLC communicates with the plant’s existing building management system (BMS) to make the whole installation intelligent and interactive.
Implementation and benefits
Initially the drives were configured to give the fans three set speeds, but the intention is to upgrade this with PID pressure sensor feedback, so that load-matching becomes exact. With the PLC and BMS working together, it has been possible to programme in tune with tea and lunch breaks, so that the air handling is not running unnecessarily when machines are idle for two hours each day.
“Simply putting drives into Stryker’s system improved their electrical usage profile, and so is saving them an extra 15% above expectations,” explains Cronin
The biggest saving for the company is, it turns out, an unexpected one. Since the facility is pulling in less outside air and they are able to recycle half of the already heated air, they are saving nearly 30% of their gas bill or more than R700 000 on heating. There is scope to further increase the recycling. This is on top of a nearly R950 000 saving that has been made on electricity, to operate the dust extraction system.
Cronin concludes: “It is projects like this that demonstrate that energy efficiency is not only environmentally responsible, but it is also very good business practice. As the costs of energy increase, more and more businesses will start to realise the value of having a system that maximises this mission-critical resource.”
For more information contact Mike Cronin, Elquip Solutions, +27 (0)11 826 7117, [email protected], www.elquip.co.za
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