Step 1-4 Draw a physical/schematic diagram, identify all possible transport mechanisms and set a frame of coordinates. Draw a shell, such as that its surface perpendicular to the transport direction The flow is totally in the direction of (upward) z. The assumptions are: L Laminar Flow KR V, = v,(r) V = Ve = 0 p=P(z) AR R We use cylindrical coordinates, r, ez, direction. 1.8.) Boundary conditions: B.C.1 B.C.2 B.C.3