174. When Should One Be Concerned With The Tube Wall Temperature On The Cooling Waterside Of A Shell And Tube Exchanger?
When designing heat exchangers where hot process streams are cooled with cooling water, check the tube wall temperature. Hewitt says that where calcium carbonate may deposit heat, transfer surface temperatures above 140 OF should be avoided. Corrosion effects should also be considered at hot tube wall temperatures. As a rough rule of thumb, make this check if the inlet process temperature is above 200 OF for light hydrocarbon liquids and 300-400 OF for heavy hydrocarbons. Consider using Aircoolers to bring the process fluid temperature down before it enters the water-cooled exchanger.
