Chapter 9 Theories of Mass Transfer page 9-1
Chapter 9 Theories of Mass Transfer
1. O2 absorption
From Ex. 8.1-1,
–kaL/v
2. Film thickness in a fluidized bed
3. Copper Adsorption
Mass balance over the bed shows that at any point z,
After integration, we have v1(c1 – c10) = v2(c20 – c2) = –v2c2
From the equilibrium data, c2(sat) = 0.4601 c1 – 6.110-5 = 14.81 c2 + 0.0257
dz = ka(c – c(sat)) = -13.81ka(c + 0.00186)
Chapter 9 Theories of Mass Transfer page 9-2
c2L + 0.00186
4. Partition of iodine in ether and water
5. Mass transfer from a sphere
1/2 1/3 0.074
-4
6. Sherwood number for wetted wall column
7. Egg breathing
8. Film theory for fast mass transfer
ev0l/D – 1 (c – c) = c v – n
9. Evaporation of a water drop
10. Mass transfer with total slip on wall
When total slip occurs, the velocity profile is a plug flow. Thus from penetration theory,
k = (4/3)
()1/2 (9/4)1/3
zD
zD
11. Methylene chloride stripping
In this problem, water evaporation augments the stripping of CH2Cl2. To emphasize this
effect, we assume for both solutes
Chapter 9 Theories of Mass Transfer page 9-4
v0
exp(v0/k0) – 1 (c – c) + c v
But for water, from Eq. 3.3-11, since v0 is independent of c1i,
v0 = n2
c = –kln(1 – y)
Combining these two equations, we have
ln(1 – y20)