Taylor-Wharton HC Series - Manual

HC SERIES
High Cap
acity Liquid
Nitrogen Refrigerators
TW-346
SAFETY
Before using any cryogenic refrigerator, read the
Handle with Care booklet provided with the unit.
It details safety precautions that must be under-
stood before using the equipment. If a replace-
ment booklet is needed, order publication TW-10
Handle with Care from your supplier.
Following are a few of the safety precautions
described in the Handle with Care booklet.
Please be sure to read the entire booklet.
Store and use these containers only in well
ventilated areas. In a confined area, nitrogen
gas from these units may cause suffocation by
displacing air needed for breathing. Install a
suitable oxygen monitor.
Do not touch liquid or cold metal surfaces
with your bare skin. The liquid nitrogen refrig-
erant in these containers is extremely cold: -
196
°C (-320°F). Exposure of skin or eyes to
liquid, cold gas or frosted parts could result in a
severe frostbite-like injury. Because of the
extremely low temperature, a face shield and
gloves must be worn when transferring liquid
nitrogen and material into or out of these con-
tainers.
OPERATION
Filling: Adding liquid nitrogen to a warm con-
tainer may cause splashing and will generate a
significant volume of nitrogen gas as cold liquid
contacts warm refrigerator surfaces. Add liquid
slowly to minimize these effects. Be sure there is
adequate ventilation. Keep your head clear of
the heavy volume of vapor that may be pro-
duced. It is extremely cold and could case
personal injury.
WARNING
DO NOT OVERFILL. Over-filling may result in personal
injury due to liquid spillage.
DETERMINING LIQUID LEVEL . Liquid level
must be checked at regular intervals – refrigera-
tion depends on the presence of liquid nitrogen.
The liquid level in the container can be deter-
mined with a dipstick. Insert the dipstick straight
into the container so that it rests on the canister
positioning fixture on the bottom of the unit. After
5 to 10 seconds, withdraw the dipstick and wave
it back and forth in the air. A frost section will
form representing the depth of liquid in the
container.
WARNING
Never use a hollow rod or tube as a measuring rod.
When a warm tube is inserted into liquid nitrogen, liquid
will spout from the top of the tube and may cause
personal injury.
The liquid level chart shows volume of liquid
nitrogen vs. depth for HC Series refrigerators.
These values are approximate and are based on
a standard condition with no stored material in
the container. With stored material, the liquid
volume will be slightly less than the value of the
chart.
LIQUID LEVEL CHART
INSERTING OR REMOVING CANISTERS: To
prevent unnecessary loss of liquid nitrogen and
accumulation of ice, the necktube core (the
stopper) should remain in the container when
the stored material is not being accessed.
When accessing stored material, the necktube
core should be removed as briefly as possible.
When removing material from the canisters,
withdraw the canister just far enough to remove
contents. Completely withdrawing the canister
will unnesessarily expose the stored material to
warm, room temperature conditions.
WARNING
Some canisters have liquid drain openings; some do
not. If canisters are completely removed from the
container, liquid nitrogen may remain in the canister
or drain from the bottom. When removing canisters,
stop briefly at the necktube to allow liquid to drain
completely, then handle the canister carefully to
prevent personal injury. Avoid direct canister contact
with bare skin. The use of proper personal protective
equipment is strongly urged – cryogenic gloves, face
shield and gown – to protect against splashing.
When room temperature product is added,
slowly lower the canister into the refrigerator to
reduce the boiling of refrigerant and the surge
of cold nitrogen gas. When inserting the
canister, tilt the bottom of the canister in the
direction of the index ring notch.
SECURING CONTENTS: The contents of all
models may be secured with a seal or lock
through tabs on the edge of the lid opposite the
hinge.
ROUTINE CARE & MAINTENANCE
If ice accumulates inside the necktube, a
general cleaning of the refrigerator should be
Operating Instructions
Model(s) Liters/inch Liters/cm
HCL12/HC20 1.25 0.5
HCL21/HC34/
HC35/HC34
2.3 0.9