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Heatless Regenerative Desiccant Dryers

Low Capital Investment. Long Life and Low Maintenance.

Next Air & Gas Heatless Regenerative Desiccant Dryers are ideal for demanding applications requiring very dry air.  Our dryers offer dewpoints ranging from -400 F to -1000 F. Our heavy duty design can operate around the clock, providing years of trouble free service with minimal maintenance.

Next Air & Gas offers two lines of Heatless Regenerative Dessicant Dryers, our HHD Series, with inlet flow capacities of 80 to 5,000 CFM, and our MDA Series of Mini Desiccant Dryers with inlet flow capacities of 10 to 45 CFM.

Should you need guidance determining which type of dryer works best for your operation, our on-staff experts are happy to do an analysis and make recommendations. You can request assistance here.

Principle of Operation

The twin tower design allows for continuous adsorption of water vapor from compressed air by using the X-PACK – a hygroscopic desiccant with high crush strength and a high surface/volume ratio. Drying is accomplished by passing compressed air through one desiccant bed adsorbing moisture while the other is being simultaneously regenerated with the expanded purge air.

Regeneration of desiccant is accomplished without the use of heat.  The wet bed is dried by diverting a small portion of the super-dry air from the outlet at near atmospheric pressure. The purge flow rate is adjustable to suit the specific outlet conditions (desired dewpoint). The super dry air flows in a counter direction through the wet bed, sweeping all the water vapor previously adsorbed by the desiccant. The DDC-15 microprocessor controller monitors the automatic operation of the dryer and provides options for load management, fixed cycle and dewpoint based control.

Next Air & Gas ensures pressure equalization in the twin towers prior to switching. This prevents line surge and minimizes desiccant attrition. The tower being reactivated will be gradually re-pressurized at the end of its reactivation cycle before switchover takes place. Purge flow and de-pressurization are in a downward direction, counter flow to the drying air flow.

Heatless Dryer Operation Diagram
Heatless Dryer Operation Key

Industry-Standard Performance
And Exceptional Quality

Optional Features

Standard Features

Heatless Dryer Charts
Model No.  Inlet (CFM)Inlet/Outlet ConnectionsL x W x H (inches)Weight (Lbs)Pre-filterAfter Filter
80-HDD80¾” NPT34x24x76550FTX-125FTP-125
100-HDD1001” NPT34x24x76690FTX-125FTP-125
125-HDD1251” NPT34x24x76710FTX-125FTP-125
150-HDD1501” NPT40x36x76810FTX-200FTP-200
200-HDD2001” NPT40x36x83850FTX-200FTP-200
250-HDD2501 ½” NPT44x40x831010FTX-300FTP-300
300-HDD3001 ½” NPT44x40x851200FTX-300FTP-300
375-HDD3751 ½” NPT46x42x851350FTX-450FTP-450
500-HDD5002” NPT50x45x901460FTX-600FTP-600
650.HDD6502” NPT50X45x901790FTX-600FTP-600
800-HDD8003” FLG55x48x1052150FTX-900FTP-900
1000-HDD10003” FLG55x48x1052960FTX-1500FTP-1500
1250-HDD12503” FLG60x50x1093470FTX-1500FTP-1500
1500-HDD15003” FLG60x50x1094180FTX-1500FTP-1500
2000-HDD20003” FLG70x62x1154980FTX-3000FTP-3000
2500-HDD25004” FLG70x62x1155800FTX-3000FTP-3000
3000-HDD30004” FLG80x70x1206400FTX-3000FTP-3000
4000-HDD40006” FLG90x80x1229100FTX-5000FTP-5000
5000-HDD50006” FLG98x86x12011800FTX-5000FTP-5000

Next Air & Gas Performance Advantages

The performance of any desiccant dryer depends on the quality of its key components. Next Air & Gas uses the best available valves, controllers and desiccant. With accurately designed and sized components, the dryers are manufactured to provide you with years of trouble-free operation.

Electronic Controllers Provide The Information You Need

All Next Air & Gas heated desiccant regenerative dryers are equipped with the state of the art PLC controllers that regulate and monitor dryer function. A simple user interface allows the operator to quickly enter settings and monitor operations, including dewpoint selection, energy cycle, diagnostics, and more. The unit can also be connected to a remote computer.

Digital Dewpoint Transmitters Optimize Operations

The digital dewpoint transmitters are compact, reliable and continuously monitor the dryer performance. With available options, monitors can be used as indicators, alarm units or as controllers. A simple interface permits the operator to choose between multiple units, output the data to a PC, set alarm levels and do field calibration of the sensor.

Quality Desiccant Media

Next Air & Gas uses a mixture of adsorption media in its heatless range of desiccant dryers to achieve consistent dewpoint. Activated Alumina, Molecular Sieve and Silica Gel are used in varying ratios depending on the application. The long lasting, high crush strength media has a very high surface/volume ratio.

High Efficiency Blower

Super-Tough, Maintenance-Free Bi-Directional Piston Valves

These non-lubricated, high quality, high performance, bi-directional piston valves are designed to handle the most severe conditions. They require no maintenance and come with a five-year limited warranty.

Angle Body Piston

Angle Body Piston Valve

These high-performance, 2-way direct acting valves are designed for reliability and durability. It uses a profiled disc in conjunction with a high-resolution compact positioner and linear feedback potentiometer to provide precise proportional flow. The stainless steel internals and a tough fiber composite actuator body, along with the use of oversized bearing and Viton® seals, make it possible to consistently provide smooth piston movement for years of trouble-free service.

Butterfly Valve

Butterfly Valves for Precise Control

These versatile, high-performance butterfly valves are used by Next Air & Gas to provide you with precision control and complete bubble-tight shut off. The digitally controlled actuators provide easy PLC interface and feature fast response time. The tongue-and-groove seat design feature ensures complete isolation of flowing media from the body and stem. Rugged and reliable, these valves are designed to provide years of trouble-free service.