
309Heterogeneous Reactors
The mean residence time
is
θ= ==
m
Mass flowrate
S
S
()
mi
h
10
30 05
The equation for conversion
B
θ is
B
()
/
θ
θ
τ
θ
τ
θ
τ
τθ
=
−
+
−
−
36 61
23
Construct the table shown below:
S. No.
Particle
Size R
i
(mm)
Weight
Fraction
w
i
Time for
Complete
Conversion
i
i
O
O
R
R
=
(h)
θ
τ
Conversion
x
Bi
1
R
1
= 1 w
1
= 0.2 τ
1
= 1
0.5
x
B1
= 0.648
2
R
2
= 1.5 w
2
= 0.3 τ
2
= 1.5
0.3333
x
B2
= 0.544
3
R
3
= 2 w
3
= 0.3 τ
3
= 2
0.25
x
B3
= 0.467
4
R
4
= 3 w
4
= 0.2 τ
4
= 3
0.1667
x
B4
= 0.361
Mean conversion
xxW
wx wx wx wx
BBii
i
BB
=
=+
=
=
=
∑
1
4
11 22 33
0 5051
50 51
.
.%
Note: Refer MATLAB program: cal_xb_mean3.m
4.1.1.2.4 Moving Bed Reactor
The cou ...