Give yourself a competitive edge by reducing production costs with a revolutionary Parker Heat of Compression Air Dryer. The unique design uses the normally wasted heat from the compressor to regenerate its desiccant. In addition to efficiently using the heat-of-compression, the Parker HOC produces extremely low dew points.
The outlet dew point from any heat-of-compression dryer is based in large part on the discharge temperature of the compressor. If the compressor, for whatever reason, does not deliver high enough temperatures, then the dryer can’t deliver low dewpoints. This has always been one of the problems with conventional heat-of-compression dryers; until now. The HOC design can be equipped with a small optional trim heater which can be automatically energized, if the regeneration temperatures are not adequate. Because the heater is located in the stripping line, it is not heating the full flow of the compressor; rather, it is comparable to a typical heated dryer. The heated stripping time is adjustable between 0 and 90 minutes, allowing the dryer to deliver low dew points under virtually any set of conditions. The heater is identical to our heated dryer design; we use an incoloy sheathed heater derated to 14 watts/sq. inch, and is controlled by a temperature transmitter that provides heater overtemp alarm and shutdown. Also provided is a temperature transmitter in the cold zone for heater shutdown, if there is a loss of flow across the heater.
Additionally, the HOC design comes equipped as standard with a heatless mode of operation. If, for example, the primary compressor is down and portable oil-free compressors are brought in for temporary use, the inlet temperature to the dryer may be as low as 100°F.
In this case, the HOC dryer can operate in a heatless mode and deliver the specified dew point. As with any heatless dryer, the HOC will now purge 15% of the inlet air.
When the trim heater option is purchased, the dryer can also operate as an externally heated dryer; another mode of operation, if the primary compressor is down and portable oil-free compressors are brought in. As with any externally heated dryer, the purge will be 7% of the inlet air.
With these two features, the HOC can deliver any required dew point, under any set of conditions, all the time.
Five key features set the HOC apart from other dryers:
Full Flow Heating
Both the HOC-SP and the HOC utilize full flow heating; all of the air from the final stage of compression is directed into the regenerating tower. We know that compressor flows vary during the course of a day or week. Heat-of-compression designs that split flow at the inlet, and only use partial flow regeneration, are unable to perform at less than 100% flow. The HOC-SP & HOC can deliver dew point as low as 15% load.
Dry Gas Stripping
The HOC uses dry outlet air to continue to regenerate the desiccant. After 90 minutes of full flow heating, the HOC begins a stripping cycle using only 2% of the dry process air to remove additional moisture from the desiccant in the regenerating tower. The net result is a lower outlet dew point.
Dry Gas Cooling
After 90 minutes of stripping, the HOC begins to cool the desiccant in the regenerating tower with dry outlet air. No air is lost during cooling. Some competitive heat-of-compression designs cool with wet air; preloading the desiccant in the regenerating tower with water making it very dif cult to deliver low dew points.
High Performance Switching Valves
All of the valves used in the HOC-SP and HOC are high performance, leak tight, and re safe. This means they work under all conditions. If a switching valve fails, or even leaks, you get wet air downstream. We recognize this fact and designed our heat-of-compression dryers to use bubble tight valves that don’t leak.
Fail Safe Drain Traps
The only place that liquid water is removed is through the drain traps. Our dual drain trap system is the most reliable drain available. The truth is, if the trap fails, then the dryer fails. Any single trap will ultimately fail. The dual drain trap uses 2 separate traps; a mechanical primary, and a liquid level sensor as a back up. The primary trap will operate reliably for a long time, but like any mechanical device it will eventually fail. When that happens, water backs up into a liquid level sensor that opens a valve draining out the water while simultaneously triggering an alarm. The water is removed; the dryer performs.