The Hilton H953 Concentric Tube Heat Exchanger allows rapid measurement of surface and overall heat transfer coefficients in turbulent flow conditions. The unit is bench mounted and self-contained. It enables detailed temperature profiles, overall heat transfer coefficients and the important relationship between Nusselt, Reynolds and Prandtl Numbers to be established.
This is a classic concentric tube type with hot water flowing through the central tube while cooling water flows through the annular space. The heat exchanger has been divided into three equal sections in order to allow examination of the intermediate stream temperature conditions and temperature distribution through the heat exchanger. Thermocouples sense the hot and cold stream temperatures at the four stations and the wall temperatures on entry and exit.
Hot water provided by an electrical heater, is fed by a pump into the upper end of the central tube of the heat exchanger. The water cools as it flows through the heat exchanger, and on leaving passes through a flow meter and then back to the heating tank, where it is reheated.
Mains cold water passes through a combined flow control valve and flowmeter to a separate pair of valves mounted on the front panel. These valves direct the cold water to either end of the heat exchanger and allow instantaneous flow reversal from concurrent to counter-current flow.
