Luas transfer panas A Beban panas reboiler Media pemanas Mencari ΔT
A-219
Vt = 3600
= 3026453.163 lb jam.ft
2
3600 x 63,2611 lbft
2
= 13.289 fts 5. Harga Reynold
ID = 0.532 in = 0.044333 ft
Re t =
persamaan 7.3 kern
= 0.044333 ft x 3026453.163 lb jam.ft
2
1,61027 lb ft.jam = 83323.24614
Dari figure 25 kern, pada Vt = 13.28906972 fts pada T = 37,5
o
C = 99,5
o
F Didapatkan heat transfer koefisien hi = 1180 Btujam.ft
2
.
o
F Sehingga hio = hi x
= 1180 x 0.044333
0,0625 = 837.0133333 Btujam.ft
2
.
o
F
Pehitungan shell side hot fluid
1. Jarak baffle B B =
ID shell 2
= 15.25
2
A-220
= 7.625 in 2. Luas flow area as
Diketahui Pt= 34 in square pitch as =
ID shell x C x B
144 Pt dimana C’ = 15.25 - 1 = 14.25 in
as = 15.25 x 14.25 x 7.625
144 x 34 = 15.343 ft
2
3. Kecepatan aliran pada shell Gs =
Fv as
= 4106.674461
15.343
2
= 267.6636998 lbjam.ft
2
G” = Fv
L x Nt
23
= 267.6636998lbjam
12 x 124
23
= 13.76241262 lbjam Asumsi ho = 400 Btujam.ft
2
.
o
F Dari hitungan tube, hio = 837.0133 Btujam.ft
2
.
o
F tw = ta+
ho hio+ho
tv-ta
= 99,5 ℉+
400 lb jam.ft
2
837.0133 + 400 lb jam.ft
2
212-99,5
= 135.89
o
F
A-221
= 57.729
o
C tf =
Tv + Tw 2
= 212.04 + 135.89
2 = 173.96
o
F Berdasarkan Carl L yaws, didapat:
- Densitas = 0,7588 kgL = 47,3491 lbft
3
- Viskositas = 0,8383 cp = 2,02869 lbft.jam - Thermal konduktivity = 0,0929 Btujam.ft
- Kapasitas panas = 0,12 Btulbm.
o
F - Spesific grafity = 1,5
Dari grafik 12.9 Kern didapat ho = 410 Btujam.ft
2
.
o
F ho trial ≈ ho hitung, memenuhi
Clean overall koefisien Uc Uc =
+ =
837.0133 410 837.0133 + 410
= 275.198 Btujam.ft
2
.
o
F Faktor pengotor:
Rd = −
= 275.198
− 119.92 275.198 119.92
= 0,004705422
A-222
Rd Rd hitung = 0,0003
Menghitung Pressure drop ΔP Pipa air pendingin
Untuk Re = 83323.24614 Pada figure 26 kern, didapatkan faktor friksi f = 0,00025 ft
2
in
ΔPt =
2
5,22 10
10
∗
= 0,00025 3026453.1637
2
12 4 5,22 10
10
0.044333 1 = 4.7495 psi
ΔPr = 4
2
2 ′
= 4 4 13.2890
2
1 2 32,2 = 4.38756 psi
P tube = Pt + Pr = 4.7495+ 4.38756
= 9.181 psi ∆
P tube 10 psi memenuhi
Shell hot fluid
Data fisik umpan pada T = 100.002
o
C berdasarkan Carl L Yaws.
A-223
- Densitas = 0,793 kgL = 49,4832 lbft
3
- Viskositas = 0,7188 cp = 1,7395 lbft.jam - Thermal konduktivity = 0,08975 Btujam.ft
- Kapasitas panas = 8,64815 Btulbm.
o
F
Nilai Reynold:
Re =
= 15.25 − −.75
1 12
267.6636998 1,7395
= 185.93 Dari figure 29, didapat f=0,001 ft
2
in
2
Number of crosses: N+1
= 12 x LB = 12 x 127.625
= 19 crosses S =
= 49,4832
62,5 = 0,79173
ΔPshell = fx Gs
2
x Ds x N + 1 2 x 5,22x10
10
x De x s pers 12.74 kern
A-224 =
0,001 267.6636998
2
15.2512 19 2 5,22 10
10
15.25 0,79173 = 1.36x10
-9
psi P shell P shell allowable 10 psi, sehingga P shell bisa diterima.
A-225
Tabel C.14.4 Spesifikasi Condensor CD
– 401
Alat Condensor
-401 Kode
CD – 401
Fungsi Mengkondensasikan produk atas distillasi DC-401
Bentuk Shell and Tube Heat Exchanger
t
LMTD
119,92
o
F Luas, A
292.0944 ft
2
Dimensi pipa Shell
: ID
= 15.25 in B
= 7.625 in Lewatan
= 4 N+1 = 19
∆P
s
= 1.36x10
-9
psi
Tube :
Jumlah = 124
Panjang = 12 ft BWG = 12
OD = 34 in
ID = 0.532 in
Pitch = 1.25 in square pitch
Lewatan = 4 ∆P
t
= 9.181 psi Clean Overall
Coefficient , Uc
275.198 btujam ft
2
.
o
F Design Overall
119.9 btujam ft
2
.
o
F
A-226 Coefficient
, U
D
Dirt Factor , R
d
0,0047 hr ft
2 o
F Btu Bahan konstruksi
Stainless Steel SA-240 A ISI tipe 316 Jumlah
1 buah