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Process Heat Transfer 183

Table 4.7 Continued

Transfer Properties

RoR = (Rfi)R + (Rfo)R (4.7.9)

Uoc-U 0
(4-7.10)
U 0U OC
hi ho
U oC= ———— (4.7.11)
hj + ho

R f ; = f(fluid', type of phase change') — Table 4.3 (4.7. 12)

hj = f(fluid', type of phase change') — Table 4.3 (4.7. 13)

ho = f(fluid', type of phase change') — Table 4.3 (4.7. 14)

R fo = f(fluid', type of phase change') - Table 4.3 (4.7.15)

Variables

m, - t z - (At) LM - h 3, 2 - h4 j2 - Q - U 0 - U oC - F - ROA - ROR - (R f OR - (R f 0) R - hi - ho

Degrees of Freedom

F=15-15 = 0

Table 4.8 Calculation Procedure for Rating Heat Exchangers____

1. Calculate the heat transferred from Equations 4.7.1, 4.7.2,4.7.7 and 4.7.8.

2. Calculate the approximate values of the heat-transfer coefficients from
Equations 4.7.12 to 4.7.15.

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