Taylor-Wharton 24K w/ AutoTend - Manual (Page 30)

Defrosting Your K-Series Cryo-Storage System
All liquid nitrogen storage systems are subject to ice and frost buildup over time.
Regular preventive maintenance programs should be instituted to remove ice and
frost from the sensor and fill tubes and from the refrigerator lid.
Ice and frost buildup in the sensor tube may result in false readings being relayed to
the controller from the sensors. Ice can form a thermal barrier around a level sensor,
rendering it insensitive to the temperature differences between vapor and liquid.
Sensors and thermocouples should be carefully removed regularly and inspected for
ice and frost buildup.
Ice and frost buildup in the fill tube may block the flow of liquid nitrogen into the
refrigerator during fill. This blockage can result in the liquid level dropping to danger-
ously low levels, and may result in the Low Alarm sensor being activated. In addition,
a fill line blockage may cause the Low LN
2
, Supply Alarm to be activated. If the fill line
becomes blocked, it must be warmed until the ice blockage is cleared. Ice blockage
would typically form in the fill tube at the point at which water will form ice. This
location may be just inside the storage chamber, near the top. Warm with a hair dryer
or other safe low heat source with the solenoid in the open position. If this is not
successful in 2 minutes, remove the fill tube from the refrigerator, allow to thaw to
room temperature, and purge with dry nitrogen or oil-free dry air to remove all traces
of moisture before re-installation.
Excessive ice and frost buildup may occur on the refrigerator lid if the lid is left open
or the liquid level is too close to the underside of the lid. To defrost the lid, open the
lid to the fully open position. Clean the ice and frost from the underside of the lid by
allowing it to thaw slightly and wiping with a clean, lint-free cloth. Care must be taken
to insulate the inventory control system from high temperatures, which may affect the
viability of the stored product.
Excessive ice and frost buildup on the lid may occur if the lid is misaligned or the
insulative gasket material is damaged. Should this occur, please contact your Taylor-
Wharton distributor for assistance.
Cleaning Your Taylor-Wharton CryoStorage System
The cryogenic vessel of all K-Series CryoStorage Systems may need to be cleaned
and sterilized if the type of stored product is changed or the unit is taken out of
service. The vessel must be cleaned and sterilized, regardless of the type of stored
product, prior to return to Taylor-Wharton for repair or maintenance
1
To clean and sterilize your K-Series CryoStorage System, first turn the unit off.
Disconnect the power source and the liquid nitrogen source. Remove all stored
product and inventory control system components. Allow the residual liquid nitrogen
to evaporate and the cryogenic vessel to warm to ambient temperature. Increasing air
flow with a room fan or blower will expedite the evaporation.
Spray the entire inner vessel surface with ample amounts of an approved disinfec-
tant.
2 Allow surface contact to be maintained for a minimum of five minutes. Rinse the
inner vessel with water, remove all water and debris, and towel dry the surface. Spray
the inner vessel surface with a 70% alcohol to water solution and maintain surface
contact for fifteen minutes. Rinse the inner vessel surface with water and towel dry.
NOTE:
Ice or frost in the sensor tube
may restrict the movement of
sensor probes in the tube. Do
not pull excessively on the
sensor wiring while attempting
to change sensor position. It
may be necessary to remove
the sensor tube from the
container and allow it to thaw
before the sensors can be
repositioned