Completely packaged dryers with
these outstanding features:
· Continuous removal of water vapor from compressed air and gas. Standard pressure dewpoints of -40°C (-40°F) Dewpoints as low as
-75°C (-100°F) available optionally.
· Lowest installation costs. Units are fully assembled, completely packaged with prefilter
and afterfilter.
· Lowest possible operating cost. Heating period control is standard with all models.
· Available with HY’s unique “AutoDew” demand
cycle control with direct reading digital dewpoint meter.
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General Information
GJ air dryers are heat reactivated, dual tower, desiccant type dryers designed to continuously adsorb water vapor from compressed air and gas. Continuous drying is accomplished by the operation of two desiccant towers. Drying takes place in one desiccant bed while the other (exhausted) bed is being reactivated. After a fixed time period of 4 hours or when the desiccant tower in service is exhausted (see “Autodew Demand Cycle Operation”) service is automatically switched from the exhausted tower to the reactivated one.
Switching air (or gas) flow from one tower to the other is fully automatic. Switchover from one tower to the other takes place only when both are at equal pressure to eliminate lines surges and to minimize desiccant attrition. Reactivation of the saturated desiccant is accomplished by a small flow of electrically heated dry air (gas) which is passed upwards (counter-current to drying) through the desiccant bed to carry away liberated moisture. HY heat reactivated dryers are designed to prevent breakthrough of wet air (gas) under specified operating conditions and to prevent heat and dewpoint “bumps” at the beginning of the drying cycle.
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Standard Features
· Pressure Dewpoints
Standard -40°C (-40°F)
Optional -100°C (-75°F)
· Counter-Current Reactivation
· Controlled Depressurization and Repressurization
· Heating Control
Heating of the desiccant bed is terminated by a temperature
controller on the basis of desiccant bed temperature. Only the
required amount of heat to reactivate the desiccant is introduced
into the dryer. This minimizes power and purge air consumption.
· Switching Failure Alarm and Dump Failure Alarm
Alarm on a failure to switch towers and failure of a desiccant tower
to depressurize for regeneration.
· Dewpoint Indicator
A colour-change type dewpoint indicator is standard, except with
dryers operating on AutoDew (see optional AutoDew Demand
Cycle Operation).
· Purge Flow Indicator
A pressure gauge connected in the purge line ahead of the purge
orifice.
· Fully Automatic Operation On a Fixed Time Cycle (standard)
GJ dryers operate on an 8 hour total cycle,
four hours drying and four hours reactivation.
All functions of the operation of the dryer are performed
automatically on a fixed time cycle with PLC controls. All dryer
functions and alarms are indicated on a text display.
Steps such as depressurization, shifting of the inlet switching
valve, start and termination of the heating period are repeated
automatically.
· AutoDew Demand Cycle Operation (OPTIONAL)
With this option the drying cycle is terminated on the basis of
efflent moisture content. This means the full adsorptive capacity
of the desiccant bed is utilized. Under certain operating
conditions there will be substantial redcutions in the amount of
purge air loss and utilities required.
· Chamber Pressure Gauges
· Chamber Temperature Indicatores
· Prefilter and Afterfilter included, (mounted on all 2” dryers)
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Typical GW Dryer Flow Schematic
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Dryer Model Selection
Tables below contain the (11) standard GJ dryer sizes and
basic information on connection size and maximum flow rates at
100 PSIG. The actual models are selected from sizing curves which
are not contained in this bulletin.
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Standard features supplied with basic model
· Fully automatic on a fixed 8 hour time cycle.
· PLC controls with text display.
· Electric reactivation.
· Prefilter and afterfilter included. Mounted on all 2” npt dryers.
Complete with differential pressure indicators and float type drain.
· 380 VAC
· 150 PSIG (1034 Kpag) design pressure.
· Heating period control.
· Switching and dump failure alarm.
· Low purge pressure alarm.
· Dewpoint indicator colour change type (not supplied
with demand cycle dryers).
· Purge flow indicator (pressure gauge).
· Alarm light and dry alarm contacts.
· Chamber pressure gauges.
· Chamber temperature indicators.
GJ dryers listed in this bulletin are designed to
operate within the following limitations:
Fluid: Air or mixture of diatomic gases of non toxic or corrosive character.
Inlet flow: Standard models from 100 to 7000 SCFM at 100 PSIG
Inlet temperature: 60 to 110°F (16 to 43°C)
Inlet pressure: 60 to 150 PSIG (420 kpa to 1035 kpa)
Note:
The Maximum capacity of the dryer is affected by the inlet temperature. Do not use these figures to select a dryer.
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Design Features
Desiccant towers
Designed and fabricated in accordance with the ASME code for unfired pressure vessels. Each dryer features separate desiccant fill and drain ports. Piping manifolds, gauges, etc. do not have to be removed to either fill or drain the desiccant. Each chamber is equipped with a stainless steel desiccant support and outlet screen.
Heaters
Electrical heaters are of the hairpin type and are enclosed inside a separate heater housing outside the desiccant chamber. Heaters are not in direct contact with the desiccant. Heaters are electrically interlocked and are de-energized on switching failure, dump failure or low purge pressure alarm.
Switching Valves
All switching valves are non lubricated valves with Teflon seats.
Control and Instrumentation
Each chamber is equipped with a pressure relief valve, thermometer and pressure gauge.
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Dimensions and Weights
Model GJ*- |
3/1 |
6/1 |
12/1 |
20/1 |
30/1 |
40/1 |
60/1 |
80/1 |
100/1 |
150/1 |
200/1 |
Flow(scfm) |
100 |
200 |
422 |
700 |
1000 |
1400 |
2000 |
2800 |
3520 |
5280 |
7000 |
Connection DN |
32 |
40 |
50 |
65 |
80 |
100 |
125 |
150 |
150 |
200 |
200 |
Length |
1150 |
1310 |
1550 |
1950 |
1780 |
2200 |
2400 |
2650 |
2930 |
3500 |
3600 |
Width |
385 |
500 |
625 |
685 |
680 |
770 |
1000 |
1100 |
1200 |
1650 |
1800 |
Height |
1370 |
1830 |
1930 |
2180 |
2600 |
2570 |
2790 |
2980 |
3200 |
3560 |
3760 |
Inlet Height |
220 |
280 |
310 |
360 |
360 |
360 |
400 |
350 |
450 |
480 |
480 |
Outlet Height |
1270 |
1750 |
1830 |
2070 |
2490 |
2450 |
2650 |
2840 |
3050 |
3360 |
3360 |
Heater power(KW) |
1.35 |
3.1 |
5.8 |
9.7 |
14.7 |
19.5 |
41.5 |
52 |
76.5 |
93 |
127 |
Weight(kg) |
370 |
665 |
1090 |
1660 |
1890 |
2580 |
4130 |
4760 |
5860 |
7280 |
9950 |
* Capacities given are for inlet pressures of 100 PSIG and 100°F inlet temperature.
* Dimension and weights are approximate.
* Please consult factory for certified drawings. |
