Water freely absorbs into
refrigerant as if soaked up by a dry sponge.
Due to its' solubility characteristics,
particularly with HCFC and HFC refrigerants,
water will continue to absorb into refrigerant
until saturation is achieved. Once saturation
is exceeded, a flooded condition is created
(see Flooded
Chiller) and the actual amount of water in
the system cannot be determined by refrigerant
analysis.
To illustrate the range of
values among refrigerant types, at 40 degrees
Fahrenheit, R-11, R-123 and R-134a will become
fully saturated at the following levels:
 |
CFC-11 - 44 ppm
|
|
|
HCFC-123 - 470 ppm
|
|
|
HFC 134a - 600 ppm
|
The impact of moisture in
refrigerant cannot be overstated. Refrigerant
moisture directly causes the formation of
acids resulting in metal corrosion (see
Rust
Particulate,
Rust & Residue),
copper plating and chemical damage to the
insulation in hermetic compressors (see
Hermetic Motor
Burnouts) and other system materials.
Metal corrosion may lead to rust and pitting
of motor bearings and copper plating may form
on bearings causing a reduction in tolerance.
Wet refrigerant may also lead to ice formation
in expansion valve, capillary tubes or
evaporators.
Typical causes of water in the
refrigerant-side of a system include (1) minor
tube leaks and leaks in end sheets; (2) leaks
in low-pressure systems (systems operating
below atmospheric pressure on the suction
side); (3) less than optimal service
procedures (e.g., failure to pull full vacuum,
charging with contaminated refrigerant); and
(4) leaving a chiller or refrigeration system
open to the atmosphere.
Hudson effectively and efficiently eliminates
moisture and the resultant contaminants either
online or offline. Where downtime is crucial,
the Company's patented online decontamination
process rapidly reduces moisture and
contaminants while the chiller or
refrigeration system continues to operate.
When downtime is not a factor, the option of
offline dehydration and decontamination is the
preferred method. Depending upon the actual
moisture level, job conditions and customer
demands, available solutions range from
recovery of the refrigerant, dehydration and
recharging of the system to a system
decontamination that includes oil removal,
refrigerant recovery, dehydration,
purification and reintroduction into the
system in a continuous process until online
instrumentation verifies that all contaminants
have been removed or that it otherwise meets
predetermined specifications.
