A bayonet cooler is used to reduce the temperature of a pharmaceutical fluid. The pharmaceutical fluid flows through the cooler, which is fabricated of 10-mm- diameter, thin-walled tubing with two 250-mm-long straight sections and a coil with six and a half turns and a coil diameter of 75 mm. A coolant flows outside the cooler, with a convection coefficient at the outside surface of ho = 500 W/m2 · K and a coolant temperature of 20°C. Consider the situation where the pharma- ceutical fluid enters at 90°C with a mass flow rate of 0.005 kg/s. The pharmaceutical has the following properties: p = 1200 kg/m3, µ, = 4 X 10-3 N · s/m2, cp = 2000 J/kg · K, and k = 0.5 W/m · K. is correct in his assertion.
(c) Would you expect the outlet temperature of the pharmaceutical to depend on whether the springs have a left-hand or right-hand spiral? Why?