Question

A charcoal briquette is formed with an initial moisture content w₀. The briquette is approximately spherical with a radius R. It is placed into a forced air dryer which produces a lower surface moisture w_s at the surface of the charcoal briquette. This sets into motion the drying process of the charcoal briquette.

(a) Define the system and draw a schematic that describes the process.

(b) Write and simply the general differential equation for mass transfer.

(c) Write and simplify the Fick's diffusion equation.

(d) List any assumptions you made in parts (b) and (c). Can we assume pseudo-steady state here? JUstify your answer.

(e) Define the initial (if relevant) and boundary conditions needed to solve this problem.

Answer 1