Operation 3 - 1
3
Operation
that power is supplied to the drain valve; the other LED in-
dicates that the drain port is open. The power indicator
turns off when the drain port opens. If either LED fails to
turn on at the proper time, refer to the maintenance section
of this manual. If the dryer is under warranty, call your local
representative for authorization before servicing.
Operation of the automatic drain valve is controlled by an
electronic timer. The drain opening can be set from 0.5 to
10 seconds. The drain cycle can be set from 0.5 to 45
minutes.
To minimize air losses, the timer should be adjusted to
open the port just long enough to discharge accumulated
condensate. The timer is properly set if nothing but air
vents at the end of the open period. If air vents for more
than a few seconds, set the timer for a longer cycle or
shorter drain opening. If liquid is still discharging when the
port closes, set the timer for a shorter cycle or longer drain
opening.

3.3 Initial Start-Up For Dryers

With Fixed Cycle Electronic

Timer Controls

(Models LS60 through LS1000 only)
WARNING!
Ensure that the dryer is de-energized, valve isolated
and fully depressurized before attempting to remove
or disassemble any dryer component or subassem-
bly. Failure to do so may result in serious personal
injury and/or equipment damage.
CAUTION: Each component of a Deltech Regenerative
Desiccant Dryer System has been selected to compliment
the performance of the other components of the system.
Therefore, use of unauthorized parts or supplies or im-
proper operation will degrade system performance.
Once the Hydrobloc LS Series Dryer System has been in-
stalled according to instructions, it is ready to be oper-
ated. The system is fully automatic and does not require
any auxiliary controls. It is designed to run continuously.

3.1 How It Works

Incoming air or gas is first passed through the system pre-
filter to remove liquid water and oil contaminants. The
dryer then removes vaporous contaminants. The dryer's
cycle control system alternately cycles the compressed
gas flow through the unit's twin desiccant chambers. As
the vapor-laden gas supply enters and flows downward
through a desiccant chamber, the contaminant vapors are
attracted to and adsorbed on the surface of the activated
desiccant.
Adsorption is an exothermic (heat releasing) process, the
heat which later contributes to regeneration. Dry gas exits
the dryer to an afterfilter for particulate removal. The clean
and dry gas then proceeds downstream into the com-
pressed air system.
While one desiccant chamber is in the Drying Cycle previ-
ously described, the opposite, off-stream chamber depres-
surizes and proceeds through a fixed time, atmospheric
pressure, regeneration cycle using a portion of the dry out-
let process air at the design dew point. This outlet air is
expanded through an orifice, further reducing the dew point.
This extremely dry purge gas, in conjunction with the heat
of adsorption, regenerates the bed. Upon completion of
the regeneration cycle, the desiccant chamber will repres-
surize and once again be placed on-stream for another dry-
ing cycle.
The dryer control system utilizes its pilot gas supply to po-
sition the dryer's inlet and purge switching valves as re-
quired for the cycle at hand.

3.2 Automatic Drain Valve

All Hydrobloc LS Series dryers are equipped with an elec-
tronic drain valve that automatically discharges condensate
from the prefilter.
The automatic drain valve has two LED indicators and a
test button to help verify operation. Pushing the test button
causes the drain port to click open. One LED indicates