STHE - Inclusion of " pipe K" and thickness in "U"

[patrickraj]

Dear members,

As in page no- 62 of Applied process design for chemical and petrochemical plants by E.E. Ludwig volume three, how to incorporate tube material thickness and conductivity in the worked out example in page no-106(Condensation in the presence of non condensables).Any suitable example.

Thanks

 

[patrickraj]

Dear friends,
The following are the equations:

Page : 106 The following common equation is used for both desuperheating and condensing.
1 1
---- = ---- + ro
U(dir) ho




Page 58 / Page 62:

1 1 Lw { Ao } 1
---- = ---- + ro + ---- {----- } + ri + ----
U ho Rw {Avg. } hi [Ai].
[Ao]

ho - film coefficient outside tube
hi - film coefficient inside tube
ro - fouling factor outside tube
ri - fouling factor inside tube
Lw - tube wall thickness.
Rw- tube thermal conductivity