HDD Series (40-5,000 CFM)
Heatless Twin Tower Regenerative Dryer:
Introducing the Air Stream (HDD) Heatless Regenerative Compressed Air Dryer series by Next. In today’s demanding industrial environment, moisture can wreak havoc on equipment and processes. It is crucial to invest in cutting-edge technology that safeguards your operations. That’s where our Heatless dryers come in.
Designed with global environmental conditions in mind and built to excel, our regenerative dryers are the ultimate solution for moisture control in compressed air systems. All dryers produced by Next are certified with ASME, CRN, UL, CUL certifications.
Whether you operate in manufacturing, food processing, pharmaceuticals—or anywhere else—our dryers provide a vital shield against the damaging effects of moisture. Our dryer series uses fully pneumatic stainless steel actuator valves rather than dated shuttle valves, which allows for independence of flow and pressure.
With industry standards of design pressure being up to 150 PSIG, we thought it best to invest in the technical advantages and manufacture our pressure vessels to run at 250 PSIG as a standard. In addition, our dryers offer dewpoint ranges from (-40 °F°/C) to (-100 °F/-76°C) for maximum dryness.
Investing in our compressed air desiccant air dryers means investing in reliability, productivity, and peace of mind. With our expertise and commitment to excellence, we provide you with the tools to achieve superior air quality and protect your valuable equipment and processes.
HDD Series Features
- Mounted Filtration
- NHDC-2300, 4.6 HMI -Touch Screen Controller
- UL, CUL, Electrical Certifications
- ASME, CRN Code Welded Pressure Vessel Certification
- Stainless Steel Angle Body Valves / Butterfly Valves
- Tower Pressure Relief Valves
- Purge Adjustment Valve
- Purge Flow indicator
- Horizontal Purge exhaust mufflers
- Tower Pressure Gauges
- Stainless steel Desiccant Strainers
- Counter-Current Re-pressurization
- Nema-12 Electrical enclosure
- Field adjustable Drying Cycle time (6,10,15 min)
- Separate Drain and Fill port
- Fail-Safe Design
- Common Alarm Output
NHDC 2300 Controller
- 4.6 Color touch screen HMI interface
- Energy management system
- Main display shows the following information
- Dewpoint
- Drying, Regenerating, and Repressurizing Side
- Time Remaining for each state
- Outputs 10+
- Digital Dewpoint Trend
- Alarm status
- Alarm log
- Process History
- Energy Savings
- Filter maintenance indicator
- Modbus TCP communication
- Remote Start Stop
Operating Voltage
- 110, 115 V / 1 PH / 50-60 HZ
- 230/208/220 V / 1 PH / 50-60 HZ –(Optional)
- 24 V DC- (Optional)
Pressure Vessel Certification
- ASME VIII, CRN
(HDD-80-2500) All Provinces
Control Panel Certification
- UL & CUL
- CSA– (Optional)
Pre & Post Filtration Microns
- Pre-Filtration grade 0.01 μm
- Post-Filtration grade 1 μm
- Secondary-Post Filtration 1 μm (Optional)
Electrical Enclosure Rating
- NEMA 12
Average Purge Air*
- 15%
Outlet Pressure Dew Point
- -40° F / ° C
- -100 ° F / -73° C (Optional)
Min/Max inlet air temperature ° F / ° C
- 40/120 ° F
- 4.4/48 ° C
Min/Max Operating Pressure
- 60/150 Psig
- 4 / 10 Bar
Design Pressure
- 200 Psig
- 13.7 Bar
HDD Series Dryer Models
Correction Factors
*Additional Flows Available Upon Request
Sizing:
Air flow capacity = Operating Pressure x Inlet air Temperature
Correction Sample:
If a compressor delivers 500 scfm at 120 psi pressure with a 120°F inlet temperature, please choose your dryer model as follows:
(500 scfm / 1.08 / .75) =617 scfm, therefore an HDD-600 would be needed.
HDD Optional Features
ALTERNATE VOLTAGES:
- ALT-V-1: 208-230 VOLTS / 1 PHASE / 50-60 HZ
- ALT-V-2: 24 VOLT DC
- ALT-V-3: 12 VOLT DC
- PC: PNEUMATIC CONTROL
ELECTRICAL ENCLOSURE:
- N4: NEMA 4: ELECTRICAL ENCLOSURE
- N4X-P: NEAMA 4X: POLYCARBONATE ELECTRICAL ENCLOSURE
- N4X: NEMA 4X: STAINLESS STEEL ELECTRICAL ENCLOSURE
- N7: NEMA 7 EXPLOSION PROOF
CONTROLLER:
- ALT-C-1 NHDC-2201: (DIGITAL CONTROLLER)
- ALT-C-3 NHABC: (ALLEN BRADLEY INTERFACE)
- ALT-C-4 NHSC: (SIEMENS INTERFACE)
CONDENSATE DRAIN:
- EFD: EXTERNAL FLOAT DRAIN
- EZLD: ELECTRONIC ZERO LOSS DRAIN
- PZLD: PNEUMATIC ZERO LOSS DRAIN
- HPTD: HIGH PRESSURE TIMER DRAIN
DEW POINT & DIGITAL MONITORING:
- DCC+DDP: DEMAND CYCLE CONTROL
- DDPM-40: DIGITAL DEW POINT MONITOR (-40° F/ -73° C)
- DDP-40: DIGITAL DEW POINT SENSOR (-40° F/°C)
- DDP-100: DIGITAL DEW POINT SENSOR (-100° F/ -73° C)
- FTS: FAILURE TO SWITCH ALARM
- DCA: DRY CONTACT ALARM
- ESS: EMERGENCY STOP SWITCH
- RSS: REMOTE START / STOP
BYPASS:
- 3VBP: THREE VALVE BYPASS
- 9VBP: NINE VALVE BYPASS
FILTRATION:
- DPF DUAL PRE FILTER
- DAF: DUAL AFTER FILTER
- SP-F: SPECIAL FILTER CONFIGURATION
- FS: FILTER SKID
- RSS: REMOTE START / STOP
PACKAGES:
- LAP: LOW AMBIENT PACKAGE
- SZ: SUBZERO PACKAGE
- RS: RENTAL SKID
CONSTRUCTION:
- NYM: NO YELLOW METAL
- SP-DIM: SPECIAL – DIMENSION
- CSA: CANADIAN STANDARDS ASSOCIATION
- CRN: CANADIAN REGISTRATION NUMBER (3000+ CFM)
- BTS: BUILT TO SUIT
- IOPG: INLET-OUTLET PRESSURE GAUGE
- IOTG: INLET-OUTLET TEMPERATURE GAUGE
- TTG: TANK MOUNTED TEMPERATURE GAUGE
- VMI: VISUAL MOISTURE INDICATOR
- SST: STAINLESS STEEL CONTROL AIR TUBING
- CR: CONTROL LINE PRESSURE REGULATOR
- EPH: ELECTRICAL PANEL HEATER
- AC: AFTERCOOLER
- TAG: STANDARD STAINLESS STEEL ID TAGS
- MGP: MARINE GRADE 2 PART EPOXY PRIMER & PAINT
*If an option is not listed, please contact our sales team to accommodate any additional options.
Your next step toward working with NEXT Air & Gas is to contact us for a Quote. Fill out the information below and give us the appropriate information needed to get started. Be sure to fill out all the contact information and our team will reach out with any questions or concerns.
If you’d rather speak to Sales Engineering, feel free to contact us at (865) 635-8178.
Below are links to product information and brochures. Please click and download at your convenience. If you have any questions or suggestions on materials you think would be helpful, please call us at (865) 635-8178.
Principle of Operation
The NEXT HDD series is extremely simple and efficient in design, it uses dry compressed air for regeneration. The hard, attrition resistant activated alumina is contained in dual towers. While the compressed air is being dried in one tower the desiccant in the other tower is reactivated.
For regeneration of the desiccant, a small amount of the dried air (from the drying tower is expanded to near atmospheric pressure in the regenerating tower. The dry air becomes super dry on expansion and readily absorbs the moisture from the saturated desiccant bed.
Because they require neither heat nor blower and utilize up draft drying and counter flow regeneration.
HDD series offers maximum in reliability. An HMI and PLC control the entire drying and regeneration process. Replacement of desiccant every few years is about the only maintenance cost.
Due to their low initial cost and low maintenance cost, HDD dryers are generally used whenever sufficient compressed air capacity is available.
Overview
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.
State of the Art PLC with Touch Screen Interface
The entire drying/ regeneration cycle is controlled by a Micro-Logix programmable logic controller (PLC), among the most reliable controllers available. The plc is supplied with a 4.6″ touch screen HMI display which, among other items, will provide the operator with the following information.
- 4.6 Color Touchscreen HMI Interface
- Energy Management System
- Main Display Provides Multiple “at a glance” Data Points:
- Dew Point -OP+
- Drying, Regenerating, and Repressurizing Side
- Time Remaining for Each State
- Alarm Status
- Process History
- % Energy Savings
- Filter Maintenance Indicator
- Modbus TCP Communication
- Remote Start Stop
- Outputs 10+
- Digital Dew Point Control Dew Point Trend
Digital Dewpoint Transmitters Optimize Operations
NEXT’s FAN-500 and 510 are the ideal dew point sensors for monitoring dew point changes for our desiccant dryers. If your needs include a set dew point of -40° F or -100° F, NEXT’s range of dew point sensors has it covered.
- Modbus-RTU Interface
- Higher Resolution of Sensor Signal Through Improved Evaluation Electronics
- Integrated Display (Fan-500)
- Pressure-tight up to 5,000 psig./350 Bar (special version)
- Extreme Long-Term Stability
- Quick Response Time
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. Beaded activated alumina is used as the adsorption media in heated desiccant dryers. The beads exhibit a very high internal surface area and high moisture separation efficiency. Each lot of desiccants is thoroughly tested for density, moisture content, abrasion resistance, surface area, mesh size and granule strength to assure that it meets strict design requirements.
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 an 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.
Angle Body Piston Valve
These high-performance, 2-way direct acting valves are designed for reliability and durability. They utilize 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. Angle body valves are used to control depressurization of the regenerating vessel and to control the dry purge air flow during the cooling phase of the process. Angle body valves offer high flow rates and long service life in compact, economical packages.
PRESSURE VESSELS
HDD desiccant vessels have been designed with a wide diameter for a large cross- sectional flow area. This results in a low flow velocity which minimizes both pressures drop across the bed and attrition of the desiccant itself. The Vessels incorporate the flowing additional features:
- Stainless steel inlet and outlet air diffusers for even flow distribution
- Stainless steel bed support on units above 3,000 scfm
- Desiccant fill and drain ports
- 1/16” corrosion allowance
- Operating pressure gauge on each vessel
- Pressure relief Valve on each vessel
PREMIUM PLEATED & WRAPPED COMPRESSED AIR FILTERS
Next offers superior filtration from 1 micron to 0.01 micron, and connections from ½” NPT to 10” FLG. Next Filters are engineered to be efficient under any parameter. Next elements offer a durable element construction with an efficient drain layer to ensure continued performance after optimal element change periods.
