10
DTX10 - DTX100 USER GUIDE
6.
Operational Notes
Never service the dryer or filters without first relieving pressure.
Check all air connections for leaks and tighten as required. Downstream air leaks will affect dew point.
Bypass air leaks will affect dew point. Only soft seat bypass valves may be used.
Dryer will not perform without proper pre-filtration, condensate drainage, and purge flow. Dryers may
require up to 48 hours of operation to reach normal operating dew points. Therefore, indicators and/or
alarms should not be recognized until that time. Applications requiring dew points lower than -40°F, or with
nonstandard operating conditions, may require additional time to reach equilibrium.
Exhaust valves and/or exhaust mufflers may have to be cleaned due to dusting in shipping and start-up.
A desiccant dryer should never be suddenly pressurized or depressurized. This will cause fluidizing and
dusting of the desiccant bed.
After start-up, some dusting may occur. This will diminish with time. Some dusting may occur with normal
operation. The Exhaust Mufflers should be cleaned regularly and an Afterfilter should be used.
Flow direction is Upflow Drying - Downflow Purge. Switching Failure Alarm is optional and the dryer must
be operating over 70 PSI for proper function of the alarm. Dryer valving is “fail-safe” on power loss. This
means the inlet valves open and exhaust valves close, allowing system to remain pressurized and air to
flow through both towers, and down stream.
The standard dryer has been designed for drying service to 150 PSIG.
The dryer must repressurize before switching.
6.1
Variable Cycle Control
The heatless dryer is equipped with Variable Cycle Control. This control allows for easy adjustment
to meet varying plant loading. By using this control, the dryer can be set to one of two standard
fixed time cycles, a) standard 100% load (10 minute), b) short cycle -80°F dew point (5 minute).
Complete cycle times are given below.
Cycle Times (time in minutes: seconds)
The short cycle will provide a -40°F to - 80°F dew point when operating at or below design
conditions. Always set the purge as if you had a full inlet flow when using these cycles. The cycles
automatically compensate for the light loading; there is no need to turn the purge down.
TOTAL
TIME
PER TOWER TIME
CYCLE
DRYING
REGEN.
REPRESS.
100% Load
10:00
5:00
4:15
0:45
75% Load
15:00
7:30
4:15
3:15
50% Load
20:00
10:00
4:15
5:45
Short (-80)
5:00
2:00
2:00
0:30
