Use Of Ammonia As A Coolant; General Information On Ammonia Refrigeration Plants/Systems; Danger For Humans And The Environment; Hazard Statements H - Modine ECO ICN Serie Manual De Uso

14 - Use of ammonia as a coolant

!
All information contained in this paragraph is generic and does not replace that contained in the
technical and safety data sheets of the coolant.
Always refer to the information contained in the safety data sheet of the coolant.

14.1 - General information on ammonia refrigeration plants/systems

An ammonia refrigeration plant/system uses a common refrigeration cycle in which ammonia is the coolant.
Schematically, a plant/system consists of a compressor, a condenser, a separator
Ammonia enters the compressor as saturated vapour at a pressure of about 2-3 atmospheres and comes out as
superheated vapour at a pressure of 8-10 atmospheres and at a temperature of about 80-90°C. In this compression
phase, ammonia receives energy from the compressor which is then subsequently used for cooling. Hot ammonia,
in the vapour phase, is sent to the condenser, which makes it liquid at output, at a temperature slightly above
ambient temperature. From the condenser, the ammonia reaches the separator that allows separating the liquid
phase from the remaining one in the vapour phase. In this step, the ammonia reduces its pressure and,
simultaneously, greatly decreases its temperature due to partial evaporation. The liquid ammonia in the separator is
cooled and sent, by means of a pump system, to the units placed in the cells, where it is evaporated again through
a metering valve. This phase transformation requires heat taken from the air of the surrounding environment, cooling
the cell and its contents. Once it has carried out its cooling task, the ammonia returns to the separator in the vapour
phase, to begin a new cycle.
The ICN unit is the part of the plant that, by means of electric fans, allows the evaporation of the liquid ammonia
and the consequent cooling of the place of installation.
This brief description highlights that plants of this type pose risks associated to extremely high and extremely low
temperatures, to pressures, electricity as well as the use of dangerous substances and various machines in
continuous and automatic operation.

14.2 - Danger for humans and the environment

- Ammonia is toxic for the airways,
- Prolonged exposure or a severe exposure to ammonia vapours may cause ulceration of the conjunctiva and the
cornea, glottis edema, bronchospasm, pulmonary edema and respiratory arrest.
- Ammonia is highly irritating to the eyes and mucous membranes, in the presence of moisture on the skin,
- Splashes of liquid ammonia can cause cold burns or burns due to its caustic action,
- Ammonia can be dangerous to the aquatic environment, particularly for fish.

14.3 - Hazard statements H

H221: Flammable gas.
H331: Toxic if inhaled.
H314: It causes severe skin burns and eye damage.
H400: Very toxic to aquatic life.
EUH071: Corrosive to the respiratory tract
Danger
Caution
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