Page 210 - Industrial Ventilation Design Guidebook

4,4 WATER PROPERTIES AND TREATMENT 1 7 i

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3
« Dynamic viscosity of 0.9 x 10" to 1.2 x 10~ Pa s
• Flash points from 108 to 263 °C
The influences these factors have on fluid flow in the tubes are as follows:
• What may be turbulent flow in the heat exchanger for water will
reduce to transitional or laminar flow for the heat transfer fluid,
reducing the coefficient of heat transfer to a value 70% or more of
that for water.
• Viscosity changes make conventional water pipe sizing tables useless;
these must be upgraded by the application of appropriate correction
factors.
• Density changes.
• Specific heat capacity changes.
• Thermal conductivity changes.
Table 4.15 gives typical properties of some fluids. For other fluids,
contact the manufacturer for exact data. With heat transfer oils, care
must be taken that chemical changes such as carbonization do not take
place.