Sullair DEX Series, User & Service Manual

DEX HEATED REGENERATIVE DRYER

SECTION 5

20

5.6

PANEL MOUNTED DATA 

DISPLAY

This device is intended to provide the equipment
operators with basic information regarding the
operation of the equipment. A copy of the data
display program is included later in this manual and
shows the various information screens that are
provided.

At power up, the display will show the default screen
that provides access to “STATUS” or “CONTROL”
information. At any time, or from any screen, the
default screen can be reached by pressing the
“Menu” button.

From the default screen, dryer “STATUS” screens
can be reached by pressing up and down arrows
From the default screen. 

 Dryer is equipped with Auto and manual switch. On
auto switch the PLC will control the function of the
dryer and in manual mode customer can step the
process for trouble shooting . When steps are made
the switch has to be turned to Auto mode.

Dry air cooling switch is also provided for choosing
dry air cooling for better dew point or ambient air
cooling if dew point spike is not issue.

5.7

EQUIPMENT START UP

During transportation and/or storage of the
equipment it is possible that the desiccant has been
preloaded with atmospheric moisture. It is
recommended to fully regenerate both desiccant
beds prior to placing the dryer in service. Thus it is
necessary for the installation to be completed and
process air to be available.

Prior to starting the regeneration the complete
installation should be checked over to verify the
following points.

1. Are the connections to and from the system

inlet and outlet made?  Are the correct size

and pressure rated connections used?

2. Is the correct electrical service connected to

the dryer with a suitably sized Disconnect

switch? With the power applied to the dryer it

is necessary to verify that the phase rotation

of the supply is correct. 

3. Ensure that all instrumentation service

valves are in the open position and all vent

valves are in the closed position. All liquid

drain service valves are to be in the open

position.

4. With the system outlet valve and bypass

valves closed slowly open the dryer inlet

block valve to pressurize the system. Check

the complete dryer system for leaks at this

time. All leaks must be repaired and re

tested.

5. Verify that all instrument and pilot air tubing

fittings are tight and that the pilot air service

valve is open.

6. With the power on verify that the PLC is in

the “RUN” mode and after a few minutes the

regeneration process for vessels “1” and “2”

will begin. Observe all operations of these

first two cycles and verify the settings of tem-

perature, pressure and valve operations in

the PLC program.

At the completion of the start up procedure the dryer

system is ready to dry the process air. Slowly open

the system outlet valve to pressurize the downstream

system. Ensure the bypass valve is closed prior to

operating the dryer.

After start up and approximately one week of service

all process piping flanges and the bolting should be

checked for tightness. Thermal cycling may affect

some gaskets from the initial bolt torque pre-loading

and thus some bolting may need to be tightened.

5.8

EQUIPMENT SHUT DOWN

The Dryer can essentially be shut down under any

“emergency conditions”

 at any time in the cycle. It

is advisable to be fully familiar with the dryer and its
operation to avoid any possible hazard or injury as
the equipment is under pressure and may be hot.
When the system is shut down and the power
removed, the dryer bypass valve must be opened
and the outlet block valve must be closed to prevent
the vessel in adsorption becoming overloaded with
moisture.

FOR PLANNED SHUTDOWNS, IT IS
RECOMMENDED TO COMPLETE THE
REGENERATION PROCESS (HEATING AND
COOLING) PRIOR TO STOPPING THE DRYER

.

This ensures that the full heating and cooling cycle
took place and that a fully regenerated bed will be
available when the system is re-started. 

If a long shut down is planned it is recommended to
remove the process flow and fully regenerate both
vessels prior to shut down. The equipment should
then be left depressurized with the system inlet and
outlet block valves closed and the power removed.
To place the system in operation repeat the start up
procedure.