ISCO 4230 - 5.2.2 Regenerating the External Desiccant Cartridge

4230 Flow Meter
Section 5 Maintenance and Service
5-3
5.2.2 Regenerating the
External Desiccant
Cartridge
Isco supplies two different chemicals in the cartridges. Before
regenerating them, you must identify the chemical your unit
uses. Both chemicals are blue when active and pink or pale
amber when saturated.
• One chemical looks like irregular chips or flakes of
tinted plaster; it is anhydrous calcium sulfate and you
regenerate it by heating at 400° - 440°F (200° - 225°C).
• The other chemical looks like glassy beads or pellets;
this is silica gel and you also regenerate by heating, but
at a lower temperature, 212° - 350° (100° - 175°C).
MSDS (Material Safety Data Sheets) for these chemicals are pro-
vided at the back of this manual.
To regenerate the desiccant cartridge:
1. Snap it out of its bracket.
2. Pull the silicone tubing from the end of the cartridge.
3. Remove one of the end caps from the cartridge by twisting
and pour the saturated desiccant into a metal, ceramic, or
other heat-resistant container.
4. Identify the desiccant and heat it at the proper tempera-
ture two to three hours, or until the blue color returns.
5. Do not try to regenerate the desiccant inside the cartridge;
the cartridge is plastic and will melt.
6. Refill the cartridge with the regenerated desiccant (or with
the extra desiccant provided in the accessory package.
7. Replace the end caps. If you have difficulty removing or
replacing the end caps, you can coat the O-rings with a
small amount of silicone oil. (Do not use any other type of
oil; it may attack the plastic.)
Notice the cotton filters behind the perforated plates in the end
caps; they keep small pieces of the desiccant material from
falling out of the cartridge. Replace these filters from time to
time using ordinary, locally-available cotton balls.
CAUTION
There have been reports of irritating fumes coming from the
desiccant during regeneration. While our attempts to duplicate
the problem have been unsuccessful, we still urge you to use
caution.
• Use a vented oven in a well-ventilated room.
• Do not remain in the room while the regeneration is
taking place.