1-805-484-2992
Quotes - Engineering - Sales
HHX Series Heatless Desiccant Dryers
| PRODUCT | TYPE | FLOW | RATING |
|---|---|---|---|
| Desiccant Air Dryer | Demand Heatless | 40 to 5,400 SCFM | 150 psig / -100°F |
Specifications
Configuration & Size
Sizes:
18 frames, 40 to 5,400 SCFM
Connections:
1 in NPT to 6 in ANSI flange
Power:
100-240 V/1/50-60 or 12-24 VDC
Desiccant:
Activated alumina, up-flow drying
Features
- A demand purge control reads bed temperature and holds each tower on line until it is actually loaded
- 7 in touchscreen with Modbus TCP/IP, RS-485 and a 30-day data log
- Stainless flow diffusers give a 4.8 second bed contact time at rated flow
- Separate fill and drain ports, so a desiccant change does not mean breaking piping
Purge that follows the load
Why a heatless dryer at light load should not purge as if it were flat out
A heatless twin-tower dryer dries the air in one tower of activated alumina while a slice of the dried air is expanded to atmosphere through the other tower to strip out the water it collected. On a fixed timer that purge runs at the full rate whether the plant is drawing the dryer's whole rating or a fraction of it. The HHX Series stops doing that: a demand control watches the heat front moving through the bed and keeps the drying tower on line until the moisture load has used it up, so the purge tracks the water coming in rather than the clock.
Eighteen frames cover 40 to 5,400 SCFM at 100 psig and 100°F saturated inlet. Up-flow drying through stainless diffusers gives every frame a 4.8 second contact time, which is what lets the same vessels hold class 1 at -100°F on a fixed 4-minute cycle, class 2 at -40°F on demand or a 10-minute cycle, and class 3 at -4°F on demand or a 16-minute cycle. The 7 in touchscreen talks Modbus TCP/IP and RS-485 and keeps 30 days of data, so a plant system can log the mode and every tower switch without a separate recorder.
Our refrigerated-vs-desiccant comparison uses about 15 percent of rated flow as the purge of a typical heatless unit, and that is the air a demand control goes after on nights, weekends and slow shifts. The controls run on 100 to 240 V single phase or a 12 to 24 VDC supply, so the dryer wires into almost any compressor room.
HHX Series Applications
From a 46 in cabinet to a 126 in pair of towers
The three smallest frames, 40, 60 and 90 SCFM, share a 32 x 32 in base and grow only in height, from 46 to 78 in, on a 1 in NPT connection at 365 to 575 lb. The 115 and 165 SCFM units share one 54 in frame at 685 lb. Ports step to 2 in NPT from 260 to 590 SCFM, to 3 in ANSI flanges from 750 to 1,550 SCFM, then 4 in at 2,100 and 3,000 and 6 in at 4,100 and 5,400 SCFM, where the dryer stands 126 in tall and weighs 12,000 lb.
Leave headroom to pour desiccant in at the top and room to drain it at the bottom, and plan the rigging: the flanged frames weigh more than a ton. Pipe a 0.01 micron coalescer ahead of the inlet and a 1 micron particulate filter after the outlet, each with isolation valves, and aim the purge muffler where the blowdown will not bother anyone. The base filtration package puts that coalescer and dust filter in place for you; the advanced package adds a particulate stage ahead of the coalescer.
Common FAQs
Read the switchover intervals in its 30-day log against what the compressors were doing at the time. At full rated flow the towers switch about as often as a timed dryer would; as the load falls each tower stays on line longer, and long gaps on nights and weekends are the saving made visible. Bring the log into the plant system over Modbus TCP/IP or RS-485 and trend it beside compressor load. If the interval never stretches, the plant runs near the dryer's rating, or the inlet is hot or wet enough that the bed really does load on schedule.
The work is in the controls rather than the piping. The HHL asked operators to pick one of eight purge economizer settings and revisit it as the plant changed; the HHX senses the bed and sets its own timing within the selected class. Communications move from the HHL's RS-232 to Modbus TCP/IP and RS-485; the HHS already offered Ethernet and Modbus, but any plant system that read either old dryer needs its point list checked against the new controller. The controls accept 100 to 240 V single phase or 12 to 24 VDC, which covers most existing supplies.
When the air arriving at the dryer carries solid dirt as well as oil: an old steel header shedding rust, a receiver never cleaned out, or a system just extended with new pipe. Scale caught by a coalescer blinds its fine media long before the element has done its oil work, so the plant buys elements on a dirt schedule and loses line pressure in between; a coarser stage ahead takes that load instead. A coalescer that keeps reaching high pressure drop long before its oil load would explain it is the sign the advanced arrangement was needed.
| Part Number | SCFM | Connection | H x W x D (in) | Weight (lb) |
|---|---|---|---|---|
| HHX-40 | 40 | 1 in NPT | 46 x 32 x 32 | 365 |
| HHX-60 | 60 | 1 in NPT | 61 x 32 x 32 | 445 |
| HHX-90 | 90 | 1 in NPT | 78 x 32 x 32 | 575 |
| HHX-115 | 115 | 1 in NPT | 54 x 44 x 38 | 685 |
| HHX-165 | 165 | 1 in NPT | 54 x 44 x 38 | 685 |
| HHX-260 | 260 | 2 in NPT | 72 x 49 x 38 | 1,010 |
| HHX-370 | 370 | 2 in NPT | 63 x 55 x 38 | 1,215 |
| HHX-450 | 450 | 2 in NPT | 71 x 55 x 38 | 1,350 |
| HHX-590 | 590 | 2 in NPT | 101 x 50 x 53 | 1,473 |
| HHX-750 | 750 | 3 in ANSI flange | 109 x 51 x 48 | 2,134 |
| HHX-930 | 930 | 3 in ANSI flange | 113 x 56 x 56 | 2,414 |
| HHX-1130 | 1,130 | 3 in ANSI flange | 113 x 59 x 56 | 2,875 |
| HHX-1350 | 1,350 | 3 in ANSI flange | 118 x 60 x 56 | 3,722 |
| HHX-1550 | 1,550 | 3 in ANSI flange | 113 x 66 x 56 | 4,167 |
| HHX-2100 | 2,100 | 4 in ANSI flange | 116 x 73 x 56 | 4,417 |
| HHX-3000 | 3,000 | 4 in ANSI flange | 122 x 78 x 65 | 9,010 |
| HHX-4100 | 4,100 | 6 in ANSI flange | 124 x 93 x 88 | 9,900 |
| HHX-5400 | 5,400 | 6 in ANSI flange | 126 x 102 x 92 | 12,000 |
