Page 395 - Chemical process engineering design and economics

Reactor Design 375

System Properties

(Ah n) nV = Ii c pi' nv/ (T R' - T 0') (7.4.17)

(Ah n+1) nvi = Si c pi' nvi, i (T R' - T 0') (7.4.18)
AH° R =H° C' -(HV -HY) (7.4.19)

k = A' exp (- E' / R' T R') (7.4.20)

Uj = f(reaction solution', jacket fluid') — Table 7.6 (7.4.21)

U c = ^reaction solution', coil fluid') — Table 7.6 (7.4.22)

Unknowns
nVi, A - x n+i, A - Ah n - Ahn +1 - AH° R - r n> A - V r - c n + 1>A - V R - Qj - U, - Aj - T, -
Q n - U c - Ac - T c - A R - Q c - P n - p - k

Table 7.5 Calculation Procedure for Sizing CSTRs____________

1. Obtain the reaction volume, V r , from Equations 7.4.1, 7.4.3 to 7.4. 5 and
7.4.20.

2. Select a standard reaction volume, V (rated capacity), from Equation 7.4.6.
R
x
3. Calculate the actual conversion, , using the rated capacity, Equations 7.4.1
n> A
and 7.4.3 to 7.4.5.
4. Next calculate the heat-transfer rate in each reactor, Q n, from Equations 7.4.2
and 7.4.17 to 7.4.19.

5. Determine if the jacket area, Aj, is sufficient.

6. Calculate the jacket heat-transfer rate, Q J; from Equations 7.4.7 to 7.4.9 and
7.4.21.

7. Determine if Qj is sufficient from Equation 7.4.10.

8. If not, determine if the coil area, A c, is sufficient.

9. Calculate the coil heat-transfer rate, Q c, from Equations 7.4.11 to 7.4.13 and
7.4.22.

Copyright © 2003 by Taylor & Francis Group LLC