Propylene Glycol based Heat-Transfer Fluids
Freezing points of propylene glycol based heat-transfer fluids suitable for the food processing industry.
For many heat-transfer applications it is necessary to use a heat-transfer fluid with lower freezing point than water. The most common antifreeze fluid - ethylene glycol - must not be used where there is a chance of leakage to potable water or food processing systems.
In food processing systems the common heat-transfer fluid is based on propylene glycol.
Freezing Points of Propylene Glycol based Water Solutions
Freezing point of propylene glycol based water solutions at different temperatures:
| Propylene Glycol Solution (%) |
by mass | 0 | 10 | 20 | 30 | 40 | 50 | 60 |
| by volume | 0 | 10 | 19 | 29 | 40 | 50 | 60 | |
| Freezing Points | oF | 32 | 26 | 18 | 7 | -8 | -29 | -55 |
| oC | 0 | -3 | -8 | -14 | -22 | -34 | -48 |
Due to slush creation - a propylene glycol and water solution should not be used close to freezing points.
Specific Gravities of Propylene Glycol Solutions
Specific gravity of propylene glycol solutions:
| Propylene Glycol Solution (%) |
by mass | 0 | 10 | 20 | 30 | 40 | 50 | 60 |
| by volume | 0 | 10 | 20 | 29 | 40 | 50 | 60 | |
| Specific Gravity - SG - 1) | 1.000 | 1.008 | 1.017 | 1.026 | 1.034 | 1.041 | 1.046 | |
1) Specific gravity based on propylene glycol solutions with temperature 60 oF.
Densities of Propylene Glycol water Solutions
| Mass Fraction of Propylene Glycol in Solution | Density - ρ - (kg/m3) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Temperature - t - (oC) | ||||||||||||
| -45 | -33 | -22 | -13 | -7 | -3 | 0 | 20 | 40 | 60 | 80 | 100 | |
| 0 | 1000 | 998 | 993 | 983 | 972 | 958 | ||||||
| 0.1 | 1012 | 1012 | 1006 | 998 | 988 | 976 | 965 | |||||
| 0.2 | 1023 | 1022 | 1022 | 1014 | 1004 | 992 | 980 | 967 | ||||
| 0.3 | 1035 | 1034 | 1032 | 1031 | 1022 | 1010 | 997 | 983 | 969 | |||
| 0.4 | 1049 | 1047 | 1044 | 1043 | 1041 | 1030 | 1016 | 1002 | 987 | 971 | ||
| 0.5 | 1064 | 1061 | 1058 | 1055 | 1053 | 1051 | 1038 | 1023 | 1006 | 990 | 974 | |
| 0.6 | 1080 | 1078 | 1074 | 1069 | 1065 | 1063 | 1061 | 1046 | 1029 | 1011 | 994 | 976 |
Boiling Points of Propylene Glycol Solutions
Boiling points of propylene glycol solutions:
| Propylene Glycol Solution (%) |
by mass | 0 | 10 | 20 | 30 | 40 | 50 | 60 |
| by volume | 0 | 10 | 20 | 29 | 40 | 50 | 60 | |
| Boiling Points (oF) | 212 | 212 | 213 | 216 | 219 | 222 | 225 | |
- T (oC) = 5/9 (T (oF) - 32)
Specific Heats of Propylene Glycol Solutions
Specific heat of propylene glycol solutions:
| Propylene Glycol Solution (%) |
by mass | 0 | 10 | 20 | 30 | 40 | 50 | 60 |
| by volume | 0 | 10 | 20 | 29 | 40 | 50 | 60 | |
| Specific Heat - cp - (Btu/lb oF) |
1.000 | 0.980 | 0.960 | 0.935 | 0.895 | 0.850 | 0.805 | |
- 1 Btu/(lbmoF) = 4186.8 J/(kg K) = 1 kcal/(kgoC)
