By Ron Marshall
A metal products manufacturer installed a desiccant dryer about 10 years ago to protect a special laser costing almost $1 million. The dryer worked perfectly, or so it seemed — it could be heard blowing off and switching sides as dual tower heatless desiccant dryers do.
As part of a compressed air study, the output of the dryer was tested using a dew point measuring device. The air dryer was originally purchased without a dew point display, saving money, so there was no way to tell the quality of the compressed air output, other than putting on an external meter.
The customer was surprised to learn that the dryer was not producing the quality of compressed air expected, rather than the minus 40 dewpoint, a dew point of only +6° was being produced. This was the dew point output of the customer’s refrigerated dryer. The desiccant dryer was not drying at all.
The customer was also surprised to learn that due to a mistake in their maintenance program this dryer had never had its desiccant changed or its filters changed. A full and complete overhaul is now scheduled. Luckily, this problem was caught in time before damage occurred in the laser.