S

wg cos

FIG. 11-8 Estimation of window cross-flow area [Eq. (11-15)]. To convert inches to meters, multiply by 0.0254. Note that lc and Ds have units of inches.

to evaluate all bulk properties of the shell-side fluid. For large temperature ranges or for viscosity that is very sensitive to temperature change, special care must be taken, such as using Eq. (11-6).

2. Findj'k from the ideal-tube bank curve for a given tube layout at the calculated value of (NRe)s, using Fig. 11-9, which is adapted from ideal-tube-bank data obtained at Delaware by Bergelin et al. [Trans. Am. Soc. Mech. Eng., 74, 953 (1952) and the Grimison correlation [Trans. Am. Soc. Mech. Eng., 59, 583 (1937)].

3. Calculate the shell-side heat-transfer coefficient for an ideal tube bank hk.

FIG. 11-9 Correlation of' factor for ideal tube bank. To convert inches to meters, multiply by 0.0254. Note that p' and Do have units of inches.
FIG. 11-10 Correction factor for baffle-configuration effects.

where c is the specific heat, k is the thermal conductivity, and |lw is the viscosity evaluated at the mean surface temperature.

4. Find the correction factor for baffle-configuration effects Jc from Fig. 11-10.

5. Find the correction factor for baffle-leakage effects Jl from Fig. 11-11.

6. Find the correction factor for bundle-bypassing effects Jb from Fig. 11-12

7. Find the correction factor for adverse temperature-gradient buildup at low Reynolds number Jr:

a. If (NRe)s < 100, find J* from Fig. 11-13, knowing Nb and (Nc +

c. If 20 < (NRe)s < 100, find Jr from Fig. 11-14, knowing J* and

8. Calculate the shell-side heat-transfer coefficient for the exchanger hs from hs = hkJcJJbJr (11-22)

FIG. 11-11 Correction factor for baffle-leakage effects.

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