Compressed air costs around R0,13 per cubic metre; it is not a cheap source of motive power at all. Therefore, it is surprising that many engineers cannot provide an overall cost to company for their compressed air systems. A typical 160 kW air compressor will consume around R1,3 million a year in power when providing a basic plant air service plan operating 24/7/365.
In a recent compressed air leak survey at a major production facility, the audit engineer found compressed air leaks accountable for costs of some R600 000 per annum. The cost of the Artic Driers service was recovered in days, not even weeks.
Ultrasonic leak detection and report generation
There are many types of ultrasonic leak detection devices, from inexpensive to high-end equipment that is capable of performing air and vacuum leak detection, steam trap malfunctions, as well as bearing ultrasound checks. The equipment used by Artic Driers during auditing is sophisticated and provides the cost per leak, as well as the actual compressed air volume lost. Tag numbers are allocated to each leak, and a page per leak report is generated on an Apple iPad using a purpose-built program.
When the company audit team leaves the site, 85% of the report is already complete and ready for download from the Cloud.
The ability to generate an Excel report is the key to targeting the worst leaks first, and the page per leak format makes the issuing of maintenance job cards exceptionally easy. Each card has an area location listed as well as a photograph of the leak with its tag number.
Should the accuracy of a report be challenged, the audit engineer will place an inline flowmeter in the supply when the facility is off line. Any air flow past the probe is then posted as leaks. The ultrasonic air leak detection gun is then used to ‘chase down’ these leaks in the plant, after which the two figures are compared. Invariably there is less than a few percent difference between the results.
Portable air auditing kits
Artic Driers International and Suto-iTech have recently launched a new fully portable device, the S600. This brand-new air auditing system is able to measure simultaneously the oil carry over into an air line, the particle count carry over, as well the dew point.
A variant of the S600 is also able to sample the compressed air in readiness for bacterial counting by a certified laboratory. This is a first In South Africa and a great asset for any laboratory or hospital complex.