48
application of the new developed solutions was restricted. Nowadays, it is the glycol
based anti-freeze solutions that have been accepted widely.
Anti-freeze solution is made up of raw alcohol, water and additives. The alcohol is glycol
and the water is distilled water. The additives include antirust agents, anti-toxicity agents,
PH regulating agents (buffering agents), antifoam agents, and other performing
enhancing chemicals.
Table 1 Physical and chemical property of glycol
Density(20
℃
)
1.113 g/mL
Flash point
116
℃
Freezing point
-13
℃
Specific heat capacity(20
℃
)
2349J/(g·k)
Boiling point ( 760mmHg)
197
℃
Vapor pressure ( 20
℃
)
8Pa
Vapor pressure ( 100
℃
)
2133Pa
Thermal conductivity ( 20
℃
)
2.889×0.004[W
／
(cm·s·
℃
)]
Table 2 The glycol concentration, density and freezing point
of the anti-freeze solution
Freezing
Point
(
℃
)
Glycol
Concentration
(%)
Density
(20
℃
)
Freezing
Point
(
℃
)
Glycol
Concentration
(%)
Density
(20
℃
)
-10
28.4
1.0340
-40
54
1.0713
-15
32.8
1.0426
-45
57
1.0746
-20
38.5
1.0506
-50
59
1.0786
-25
45.3
1.0586
-45
80
1.0958
-30
47.8
1.0627
-30
85
1.1001
-35
50
1.0671
-13
100
1.1130
The anti-freeze solution is classified to be the direct-use type and the concentrated type.
The concentrated type can not be used directly and must be diluted to a particular
concentration as stated in Table 2 according to the operating temperature.
