H971 LaminarViscous Flow Heat Transfer Unit
Heat transfer is allowed to take place between oil and water in a concentric tube. Oil flowing in the inner tube is supplied by an international oil company and has a kinematic viscosity at 70°C, of approximately 8x10-6 m2 s-1.
The oil is raised to a maximum temperature of 90°C in a tank fitted with an electric heating element. Control is by a panel mounted digital PID controller and the maximum temperature is limited by a separate thermostat for operator safety.
The heated oil is pumped from the tank into the core tube of the diagonally mounted concentric tube heat exchanger. As it flows downwards, the oil is cooled as heat is transferred to the flow of cooling water which surrounds the core tube.
On leaving the oil passes through a flow control valve to a strong glass measuring cylinder fitted with a contents scale. By measuring the volume change over time, an accurate flow rate may be determined. A quick acting valve and internal overflow allows oil back to the heater tank for re-circulation.