The PNEUDRI range of heatless and heat regenerative dryers from domnick hunter has been extended with a desiccant dryer that uses the latest aluminium forming technology to radically reduce weight and bulk.
PNEUDRI systems produce totally clean and dry compressed air down to -40 deg C pdp as standard and can be supplied with a dewpoint of -70 deg C pdp. PNEUDRI systems are used throughout Australian industry to remove impurities that can adversely affect processes powered by compressed air. In underground coal these would include pneumatically powered tools and refuge chambers.
The latest, patented, PNEUDRI range saves weight and bulk by using a single high tensile aluminium extruded section containing two desiccant chambers. This modular design eliminates the need for complex valves and interconnecting piping.
The extruded aluminium columns are bolted together in such a way that additional units may be added to increase the compressed air capacity, facilitating further plant expansion.
The DDS system used with PNEUDRI equipment operates by continuously testing and measuring the outlet air quality (or dewpoint) of the dryer and adjusting the duration of desiccant chambers’ drying and purging cycles to suit variable operating conditions. The fewer cycles the machine goes through in an hour, the less energy it demands.
Normally a dryer is set up to cope continuously with the worst peak loads it might encounter which might occur for only 5% of the time the dryer is in use. Over a day’s work cycle wide fluctuations may be caused by ambient air conditions or periods of low demand. Over a year’s work cycle, the peaks can vary just as much - the dryer might have to cope with extremely warm days and high humidity for only 15 days out of 365.
It makes environmental and economic sense for the machine to be able to evaluate the humidity of the air it is dealing with and to slow down its cycles during the extended periods when full capacity is not required.
The company said the DDS system saves considerable volumes of compressed air that would otherwise be consumed by frequent purging of the air dryers’ desiccant chambers.
