Additional Homework Problems

P8-30B

Radial flow reactors are used to help eliminate hot spots in highly exothermic reactions. The velocity is highest at the inlet and then decreases as the fluid moves away from the inlet. The overall heat-transfer coefficient varies with the square root of the radial velocity:



And at the inlet U = U(r = r0) = 100 BTU/(h ft2 °F)


  1. Rework problem P8-6 for a radial reactor.

  2. Rework problem P8-12 for a radial reactor.

  3. Consider the flow conditions to one of the tubes for the SO2 oxidation described in Example 8-10. Replace the tube with a radial flow reactor 1 cm in height with an inlet diameter of 0.5 cm. The reactor is immersed in the same boiling liquid as in Example 8-10. Plot the temperature and conversion as a function of radius and catalyst weight for three different inlet temperatures. Study the behavior of this reactor by varying a number of parameters, such as flow rate and gas composition.

  4. The reaction discussed in problem P8-15 is to be carried out in a single plug-flow reactor immersed in the same coolant. The tubular flow reactor is 2 ft in diameter. The height of the radial flow reactor is 1/2 in and the diameter of the inlet is 1 in. In both cases the coolant temperature is 100°C and the overall heat-transfer coefficient is 2000J/(m2 h °C). Plot conversion and temperature as a function of reactor radius.

[3rd Ed. P8-18]