RS COMPACT FREEZE TUNNEL, Руководство по эксплуатации и обслуживанию

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OPERATION & MAINTENANCE MANUAL
CompactFreezer
6
2.4. LIQUID NITROGEN HAZARDS
Inform all personnel about the potential hazards related to the use of liquid nitrogen in chilling
equipment!
COLD BURNS: The freezer operates on liquid nitrogen, which can reach temperatures as low as -320°F (-
196°C). Physical contact with the liquid nitrogen can cause cold burns and tissue damage. Avoid any
direct contact with liquid nitrogen or mediums/metal in direct contact with liquid nitrogen by wearing
suitable safety gear (safety glasses, facial shield, long
‐ sleeved clothes, long pants, appropriate thermal
insulated gloves). The surface of the product leaving the freezer is at sub ‐ zero temperature and should
not be handled without sufficient protection. This also applies to the internal surfaces of the freezer
when just opened.
HIGH PRESSURE INJURY: Never trap liquid nitrogen in a line without safety relief valves. As liquid in the
pipe warms, it expands while changing to a vapor and causes the pressure to increase. Unless this
pressure can bleed back into the supply tank or out a safety relief valve, it may burst the line. Safety
relief valves should be piped to an outside area. Always open valves slowly in case of a leak downstream.
Know where shut
‐ off valves are in case of an emergency.
OXYGEN DEFICIENCY: Nitrogen is a colorless, odorless, non ‐ toxic gas. The atmosphere we breathe is
78% nitrogen by volume. However, nitrogen gas can displace the air in the area surrounding during the
evaporation of liquid nitrogen and cause asphyxiation. An appropriately sized exhaust system needs to
be installed with the freezer to remove the spent vapor outside of the building. This is to prevent the
nitrogen concentration in the room air from building up to an excessive concentration and reduce the
amount of life supporting oxygen in the air to an unacceptable level.
Oxygen concentrations in the ambient (i.e. room) atmosphere should always be higher than 19.5%, the
lower limit according to OSHA. Exposure to atmospheres containing 16% or less of oxygen will lead to
unconsciousness without warning! Please refer to the MSDS sheet in the Appendix to see the effects of
lower oxygen levels on the body.