A compressed air leakage and end use study was completed by an auditor at a printing plant. A number of leakage points were identified, and during the course of the ultrasound survey a few inappropriate end uses were identified because they, too, produce an ultrasonic signal.
One compressed air consumer that was identified as inappropriate was a compressed-air-powered ionizer bar that was situated over a web of printed material. This ionizer deposited a stream of ionized air onto the paper web to prevent the paper from sticking together due to static, which causes problems in the finishing process.
Measurements showed that this ionizer consumed 15 cfm of compressed air costing about $2,600 per year. This device had been installed and forgotten, it was still continuously emitting a flow of compressed air even when the press was shut down. Due to the high energy intensity of the compressed air used by this device, this item wastes significant energy.
Fortunately, there is an alternative — the plant also uses fan-powered ionizers on another press line. These devices emit the same flow of ionized air, but uses fractional hp fan power to deposit the stream. This device uses less than $300 per year in electricity, a significant reduction over compressed air power.
Modifications are underway to correct the situation and eliminate the compressed air powered ionizer.