DOMNICK hunter has introduced a range of compressed air drying systems that are only 60 per cent the size and weight of conventional designs but which save more energy.
Its Pneudri range of heatless and heat regenerative dryers has been extended with a desiccant dryer that uses the latest aluminium forming technology to reduce weight and bulk.
Pneudri systems produce totally clean and dry compressed air down to -40°C pdp as standard (ISO 8573.1 Class 1.2.1). For critical situations, they can be supplied with a dewpoint of -70°C pdp (ISO 8573.1 Class 1.1.1).
The systems are widely used throughout Australian industry to remove impurities that can adversely affect processes powered by compressed air.
Business development manager John Davis said Pneudri systems' performance could be further extended with domnick hunter's Dewpoint Dependent Switching (DDS) energy management system, designed to save up to 80 per cent of power consumed during the process of drying compressed air.
The optional DDS systems fits all Pneudri adsorption compressed air dryers or can be retrofitted to its dryers currently in service within a wide range of industries.
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.
"Multibanking dryers enables individual banks to be easily isolated for maintenance - or even an increase in air capacity requirements, such as a night shift," Mr Davis said.
The DDS system 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.
Mr Davis said normally a dryer was set up to cope continuously with the worst peak loads it might encounter.
“Regardless of the fact that these peak loads might occur for only 5 per cent of the time the dryer is in use, it operates all the time as if it was required to provide its full rated capacity.
"In actual service, of course, compressed air systems are rarely required to operate at full capacity all the time,” he said.
“Over a day's work cycle there are wide fluctuations caused by factors such as shift work, ambient air conditions and 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.
"So 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 DDS system saves considerable volumes of compressed air that would otherwise be consumed by frequent purging of the air dryers' desiccant chambers.
The chambers are purged to release the water vapour collected by the desiccant within them. When the dryer switches to a purge cycle, compressed air is used to release the water vapour, exhaust them from the dryer and restore the desiccant for the next operating cycle.
"If the machine is going through operating cycles unnecessarily quickly for the conditions, it is wasting compressed air by purging desiccant which doesn't require it,” Mr Davis said.
“Instead, it makes a lot more sense to extend the drying cycle when conditions are suitable. During this extended period of energy-free drying, no purge energy is consumed and the machine is operating to its optimum efficiency."
Domnick hunter recently doubled the size of its Australian headquarters to cope with expanding demand for its advanced technologies, which also include gas generation, breathing air purification, sterilisation of process liquids and air and safe disposal of compressed air condensate.