P hidrostatik =
ρ x g x h =
996,6 x 9,8 x 2,354 =
pa =
psi P design =1,05 x P hidrostatik
= psi
tj =
in
18. COOLER C-01
Fungsi :
Untuk mendinginkan produk dari reaktor asam oksalat type
: Shell and tube heat exchanger
bahan :
Stell pipe IPS Temperatur fluida panas masuk T
2
= 80
o
C =
o
F Temperatur flluida panas keluar T
1
= 55
o
C =
o
F Temperatur fluida dingin masuk t
1
= 25
o
C =
o
F Temperatur fluida dingin keluar t
2
= 45
o
C =
o
F Dirt factor Rd fluida panas
= Dirt factor Rd fluida dingin
= Total Rd
= ΔP yang diizinkan
= 10 psi
Rate massa fluida yang masuk Wl =
kgjam =
lbjam Q media pendingin
= kkaljam
= btujam
Rate massa air dingin masuk W
1
= kgjam
38.410,475 152.297,53
2.542,552 176,0
131 77
113 0,001
0,001 0,002
2.298,869 5.068,087
3,357
3,525
1,250 22.992,809
tj= PD
2SE−0,6PD +nC tj=
, 2x18750 x 0,8−0,6 x ,
+10 tahun x 0,125 intahun
Universitas Sumatera Utara
= lbjam
Direncanakan dipakai Heat Exchanger dengan ukuran Bagian tube
: OD,BWG
: in
Pitch :
1 in triangular pitch panjang tube
: 16 ft
Dari tabel at
: in
a :
ft2 Passed
: 2
1.Neraca Massa dan Energi W larutan
: kgjam
= lbjam
Cp larutan :
kkalkg
o
C =
btulb
o
F Q larutan
: 5068,087 x 0,517 x 176 - 131
= btujam
2.Dt Untuk aliran counter - current ;
Ft = Kern,1983
Δt = FT x LMTD =
3 Temperatur kalorik Tc =
o
F tc
=
o
F 0,940
54,881 153,500
104,000 S
= t
2
- t
1
= 36
= 0,571
T
2
- t
1
63
o
F ln Δt
2
Δt
1
0,154 R
= T
2
- T
1
= 45
= 1,250
t
2
- t
1
36 131,0
suhu rendah 77,0
54,0
LMTD =
Δt
2
- Δt
1
= 9,000
= 58,384
0,517 0,517
118.000,274
Panas Dingin
Beda 176,0
suhu tinggi 113,0
63,0 5.605,310
1 12
0,063 0,131
2.298,869 5.068,087
Universitas Sumatera Utara
Trial U
D
Dari Kern,1983 diketaui overall design coeffecient U
D
untuk sistem cooler Light organik -air
= 75 -150 btuj.ft
2
.
o
F Kern,1983 tabel 8
Diambil harga UD =
112,5 btuj.ft
2
.
o
F Check Up
Q =
U
D
x Dt
x A
= ft
2
Nt =
a x
L =
= x
16 Digunakan 4 lewatan pada tube n-4
Standarisasi harga Nt Kern, tabel 9 : Untuk OD = 1 in, 8 BWG
NT standart =
A =
NT x a x L =
20 x 0,131 x 16 =
ft
2
= btuj.ft
2
.
o
F Jadi digunakan spesifikasi cooler :
Bagian Shell : IDs
= 1 in
n =
2 buah
B =
1 x IDs =
in Bagian Tube :
OD, BWG
Nt =
buah ID =
in Pt
= in
L =
ft a
= ft
2
ft n
= buah
at =
in
2
C = in
0,063 0,50
51,330
8 12
12 20
0,282 1
16 0,1309
2 28,67
A 28,67
13,69 0,131
20
41,888 U
D
koreksi =
Q =
118.000,274 A x Δ
t
41,888 x 54,881 A
= 118000,274
75 54,88
Universitas Sumatera Utara
EVALUASI PERPINDAHAN PANAS
Fluida panas ; Shell size, solution Fluida dingin : tube size, water
1 1
at = in
at =
Nt x at =
= ft
2
= ft
2
2 W
2 Gt =
wat as
= lbjam.ft
2
= lbjamft
2
3 Pada Tc =
o
F 3
Pada tc =
o
F μ =
0,765 Cp μ = 0,0251 Cp
= 1,855 lbft jam
= 0,0608 lbft jam
De = 0,73 in
De = 0,654 in
De = 0,061 in
De = 0,055 in
De x Gs De x Gs
= =
4 jH =
20 4
v =
5 Pada Tc =
o
F 3600 x r
k =
Wm
o
C =
btujft
2
.
o
F =
btujam ft
o
F c
= 0,32 btulb
o
F hi
= btuj.ft
2
.
o
F cμk
13
= hio =
hi.ID 280 x 0,282
6 ho = jH.kDecμk
13
.Փs =
= 7
Փs = 1 dan Փt =1 9.787,049
0,061 160.971,194
177.946,338
= 0,500
119,438 157,920
5.744,014 Gt
153,50 0,155
812,986 0,084
280 2,350
153,50 104,00
Re,s =
= 10.655,146
Re,t =
= m
1,855 m
0,347 0,032
Gs =
= 5.068,087
0,347 =
5.605,310 14.596,091
0,032 as
= IDs x CB
0,063 144.Pt.n
= 100
1,260 288,000
20 x 4
Universitas Sumatera Utara
8 Koefesien clean overall Uc h
io
x h
o
h
io
+ h
o
9 Dirt factor, R
d
: R
d
= U
C
- U
D
= =
U
C
x U
D
Preasure Drop
1 Untuk Res = 684,842 1
Untuk Ret =
f =
ft
2
in
2
f =
ft
2
in
2
s =
2 ft
2 Menghitung
Dp karena panjang =
pipa DP
t
= 5.22 x 10
10
x D x s x f
t
= ft
DP
t
= 3
= psi
= 3
Menghitung Dp karena tube
passes =
psi Untuk Gt =
DP
s
yang diijinkan = psi
V
2
Kern Gb. 27 memenuhi syarat
2g 4n
x V
2
s 2g
= psi
DP
T
= DP
t
+ DP
r
DP
T
= psi
DP
s
yang diijinkan = memenuhi syarat
DP
r
= 0,184
0,695 10
177946,338 DP
s
= f x G
s 2
x D
s
x N+1 0,511
5.22 x 10
10
x D
e
x s x f
s
12271442,36 3184200000
0,0039 10
= 0,023
7,680 Ds
= 25
f x G
t 2
x L x n 12
2,083 1621242845
3173760000 16,7
0,0027 6120
29.522,439 0,004
0,002 1
N+ 1 =
12L =
192 B
8 U
C
= =
18862 =
68,00 Btujamft
2 o
F 277
Universitas Sumatera Utara
19. FILTER PRESS FP-01
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