D-1
Z MED Medical Air System
4107 9022 67.00
D.1 General Information
CAUTION:
This manual is designed to serve as
the operation and maintenance guide for your
dryer. The contents of this manual should be
carefully read BEFORE attempting any phase of
operation or maintenance. Failure to follow the
operating and maintenance procedures of the
instruction manual could result in personal in-
jury or property damage.
All information, specifications, and illustrations
within this manual are those in effect at the
time of printing. The manufacturer reserves the
right to change or make improvements without
notice and without incurring any obligation to
make changes or add improvements to products
previously sold.
When requesting information, service, ordering
of spare parts, etc., please reference all
information supplied on the serial number plate
located inside the dryer control panel.
To facilitate maintenance, recommended
spare parts for your specific dryer model are
available. Failure to maintain recommended
spare parts and filter cartridges might result in
expensive and unnecessary downtime for which
the manufacturer cannot be responsible. To
request a quotation of, or place an order for,
recommended or emergency spare parts, please
contact your local distributor.
D.1.1 Drying Cycles
This fully automatic, heatless type dryer
alternately cycles the compressed, process gas
flow through two desiccant charged towers
where the entrained, vaporous moisture content
of the gas is adsorbed. One desiccant tower
is always on-line in a drying cycle throughout
normal dryer operation. The opposite, off-line
tower is in a regeneration cycle for removal of
the previously adsorbed moisture content. (See
D.2 and D.3 for Basic Dryer operation)
D.1.2 Continuous Purge Mode
When the dryer selector switch on the Central
Control System (CCS) panel is in the “continuous
purge” position, the dryer will shift towers based
on a factory pre-set time interval regardless of
dew point reading. This time interval setting will
vary based on dryer size. At normal operating
conditions, one tower will be at the system
pressure while the other tower is at “0” psi.
During tower changeover, the second tower will
go through a re-pressurization cycle to equalize
the pressure between the two towers and then
switch to the second tower. The first tower will
then be exhausted, and then the tower goes
through the regenerating (purge) cycle.
D.1.3 Controlled Purge Mode
When the dryer selector switch on the Central
Control System (CCS) panel is in the “controlled
purge” position, the dew point monitor controls
the dryer tower switching based on the dew
point condition. When the dew point reading is
above the setpoint of -10ºC (14ºF), the dryer will
function normally (one tower at system pres-
sure, one tower at “0” psi.). When the dew point
is below the setpoint of -10ºC (14ºF) on the dew
point monitor, the dryer will continue to use the
first tower until it can no longer maintain the
dew point setting. At this time the dryer will go
through the process of switching to the second
tower and regenerate (purge) tower one. The
dryer will continue to flow gas through the sec
-
ond tower until tower two can no longer hold
the set dew point and then switch back to the
first tower.
Appendix D - Desiccant Dryer
