Festo’s Steve Sands says that saving energy and money on compressed air with existing machinery is not difficult and does not necessarily require expensive consultants or surveys.
A structured approach to the problem of energy saving and a relatively small investment in time and updating can quickly deliver substantial returns. Some of the most critical actions that can be taken are to identify functions on a machine that require high and low pressures and use zoning plates in manifolds. Then, modern regulator manifolds can be deployed to optimise the air pressure in each. Unused sections of the system can be isolated using timed or controlled shut off valves, particularly at night or during partial operating shifts.
Point-of-use pressure regulators should be set to the minimum required pressures. Lower pressures often allow cylinders to operate faster by reducing the quantity of free air that needs to be exhausted during every stroke. And clogged filter elements that restrict the airflow should be replaced.
Pressure regulators should be mounted directly in the port of cylinders to minimise air consumption in the return or non-working stroke direction.
Leaks from split tubing, loose fittings, worn valves and cylinders should be identified and rectified. Large flows can be heard when the machinery is quiet, particularly at night. Finer, but nonetheless, costly flows can be detected using leak detection liquid, diluted washing up liquid or, for a drier approach, an acoustic sniffer or electronic leak detector.
As with most efficiency initiatives, many small individual actions can be undertaken relatively cheaply and yet their combined effect can be dramatic. It is wasteful that, until now, most maintenance departments have not been tasked with improving plant efficiency.