Doyle Dryers
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Heatless Air & Gas Dryers - Series HP


The Doyle Series HP Heatless air and gas dryers are designed for capacities ranging from 10 to 3,000 SCFM and outlet dew points from -40°F to -100°F at line pressure. Standard units are designed to handle saturated inlet air or gas at 60 to 150 PSIG and 40 to 120°F.

Heatless gas dryer diagram

Regeneration is accomplished by dry air/gas purge at atmospheric pressure plus a short five (5) minute vessel switching cycle to utilize the heat release from adsorption of moisture on the adsorbent. This process requires no heat for regeneration; however the purge air/gas rate for regeneration is considerably higher than heat reactivated air dryers. Heatless air dryers
are normally the most economical selection for use with air cooled compressor aftercoolers where the dryer Inlet air temperature is 110 to 120° F.


The Doyle Series HP Heatless air and gas dryers are most commonly used for Natural Gas, Other Fuel Gas and Process and Instrument Air systems. 

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To CONSERVE PURGE AIR/GAS, an adjustable flow control system is provided to allow decreasing the purge flow rate when operating at less than the design capacity.

STAINLESS STEEL SCREENS at the vessels inlet and outlet nozzles hold the adsorbent in the vessels.

Each unit has an AUTOMATIC REPRESSURING valve that pressures up the regenerated vessel to protect the adsorbent and prevent temporary loss of downstream pressure. This feature is required with the short five (5) minute switching cycle to prevent rapid break down of the adsorbent particles from the frequent pressure surges.

A PURGE SILENCER is provided to reduce the loud noise associated with depressuring the vessels every five (5) minutes. The silencers are rated to maintain the noise level as 85dBA or less at a distance of 3 feet from the unit.

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  • Series HP Air Dryers The series HP Heatless air dryer is a completely packaged system with fully-automatic controls and weatherproof or explosion proof electrical construction. Only the process air and electric power connections are required to place the unit in service.
  • A complete charge of activated alumina adsorbent is provided installed in the adsorber vessels.
  • Pressure gauges are provided on each vessel.
  • Each vessel has a pressure relief valve.
  • Vessels are ASME Code construction with code stamp designed for, at a minimum, a pressure of 150 PSIG at 400°F with a 1/16" corrosion allowance, or to specific job requirements.
  • Each vessel has separate adsorbent fill and dump connections.
  • Electrical components and wiring are furnished in accordance with the National Electrical Code.
  • Piping, flanges and fittings are all carbon steel construction and fabricated to ANSI standards.


  • Color change moisture indicator on dry air outlet line.
  • Panel lights to indicate which vessel is on stream drying.
  • Four-way switching valve sensor to signal customer alarm on switching failure.
  • High humidity sensor with customer alarm contact.
  • Energy saving moisture load control.

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Industries & Markets Served

Oil Exploration
Petroleum Refining
Gas Processing
Utility Companies
Steel Mills
Paper Mills

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Doyle Dryers LLC: PO Box 309  Sapulpa, OK 74067  Tel: 918-224-4002  Fax: 918-224-1195 Email: Privacy Policy
Air Dryers — Process Gas & Liquid Dehydrators & Treaters