These flow charts illustrate how the HC employs an 8 hour time cycle, cooling and stripping cycle to prevent dewpoint bumps at tower shift, and provide lower overall dewpoints.

Left Tower Heating

Hot air directly from the compressors enters the inlet of the HC and is directed by the inlet 2-way valves into the regenerating tower. This hot, thirsty air regenerates the bulk of the water from the desiccant. The air is then directed into the aftercooler where it is cooled, the coalescing separator where liquid water is removed through the drain trap system, then into the drying tower where the air is actually dried to its final low dewpoint.

View larger image of the Left Tower Heating.

Left Tower Stripping

The heating cycle lasts 90 minutes.  At the end of heating, the inlet valves shift position, directing the hot inlet air directly into the aftercooler, separator, and drying tower.  We now begin stripping.  The stripping phase of regeneration lasts 90 minutes.  At the beginning of stripping, the regenerating tower is depressurized through a muffler.  During stripping, a small adjustable flow of dry air is used to re-move the last little bit of moisture from the regenerating tower.  The allows the HC dryer to provide exceptionally low dewpoints.

View larger image of the Left Tower Stripping.

Left Tower Cooling

At the end of stripping, the regenerating tower is repressurized.  The outlet cooling cycle valves open and cooling begins.  During cooling, a portion of the dry outlet air is directed into the regenerating tower to reduce the temperature of the bed prior to tower shift.  There is no air lost during cooling.  Cooling and stripping combine to provide extremely low dewpoints and to eliminate dewpoint fluctuations during tower shift.

View larger image of the Left Tower Cooling.

The HC Model is also available with other options for optimum performance;
an optional booster heater and a heatless mode option (Patent Pending).

Learn more about the
Sahara-Pak models: 

Features: SP & HC

Theory of Operation: SP, HC

Specifications
& Dimensions: SP, HC

Options for Optimum
Performance: HC

Back to Sahara-Pak Introductory Page

Available in Acrobat Reader's PDF format

Sahara-Pak Heat-of-Compression Air Dryer

Ref. No. 058pdf

Check out our Literature page for brochures about Sahara's other air dryers, accessories, and helpful reference guides.