Assignment:
A hollow, porous cylinder 25 m in OD, 15 mm in ID is fed internally with liquid diethyl ether at 293 K. The ether flows radially outward and evaporates on the outer surface. Pure nitrogen at 373 K and 1 atm flows perpendicular to the cylinder axis at 3 m/s, carrying away the evaporated ether. The ether flow is to be that which will just keep the outer surface of the cylinder wet with liquid. Since mass-transfer rates vary about the periphery, the cylinder will be rotated slowly to keep the surface uniformly wet. Calculate the surface temperature and the rate of ether flow, in kg/h per meter of cylinder length.
Provide complete and step by step solution for the question and show calculations and use formulas.