P hidrostatik =
ρ x g x h =
918,4 x 9,8 x 3,181 =
pa =
psi P design =1,05 x P hidrostatik
= psi
tj =
in
23. COOLER C-02
Fungsi :
Untuk mendinginkan larutan dari 100
o
C menjadi 55
o
C sebelum masuk ke crystallizer
type :
Shell and tube heat exchanger bahan
: Stell pipe IPS
Temperatur fluida panas masuk T
2
= 100
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
59.758,87 3.008,784
131 77
113 0,001
0,001 0,002
647,584 1.427,663
45.453,869 18.345,802
2,678
2,812
1,250
212,0 tj=
PD 2SE−0,6PD +nC
tj= ,
2x18750 x 0,8−0,6 +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
: 1427,663 x 0,517 x 204,8 - 131
= btujam
2.Dt Untuk aliran counter - current ;
Ft = Kern,1983
Δt = FT x LMTD = 3 Temperatur kalorik
Tc =
o
F tc
=
o
F Trial U
D
0,940 69,786
171,50 104,000
S =
t
2
- t
1
= 36
= 0,364
T
2
- t
1
99
o
F ln Δt
2
Δt
1
0,606 R
= T
2
- T
1
= 81
= 2,250
t
2
- t
1
36 131,0
suhu rendah 77,0
54,0
LMTD =
Δt
2
- Δt
1
= 45,000
= 74,241
0,517 0,517
59.832,497
Panas Dingin
Beda 212,0
suhu tinggi 113,0
99,0 6.633,165
12 12
0,063 0,131
647,584 1.427,663
Universitas Sumatera Utara
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 =
75 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 = 34 in, 18 BWG 18
NT standart =
A =
NT x a x L =
24 x 0,1963 x 16 =
ft
2
= btuj.ft
2
.
o
F Jadi digunakan spesifikasi cooler :
Bagian Shell : IDs
= 8 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
11,43 A
11,43 5,46
0,131
12,793
15 14 12
12 32
0,282 1
16 0,1309
2 1325,418 x 66,962
A =
59832,497 75
69,79
32
67,021 U
D
koreksi =
Q =
59.832,497 A x Δ
t
Universitas Sumatera Utara
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 =
10 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 40 x 0,654
6 ho = jH.kDecμk
13
.Փs =
= 7
Փs = 1 dan Փt =1
EVALUASI PERPINDAHAN PANAS
9.830,589 0,061
= 0,750
55,943 22,560
517,782 161.687,312
Gt 171,50
0,145 816,603
0,084 40
2,350 178.737,974
171,50 104,00
Re,s =
= 960,486
Re,t =
= m
1,855 m
1,085 0,037
Gs =
= 1.427,663
1,085 =
6.633,165 1.315,734
0,037 as
= IDs x CB
0,334 144.Pt.n
= 312,5
10,688 288,000
114 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 =
lbjamft
2
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
0,699 10
7,680
DP
s
= f x G
s 2
x D
s
x N+1 0,515
5.22 x 10
10
x D
e
x s x f
s
99714,61 3184200000
0,00003 178737,974
10 =
0,023 Ds
= 25
f x G
t 2
x L x n 12
2,083 1635699878
3173760000 3,3
0,0023 1447
29.522,439 0,004
0,002 1
N+ 1 =
12L =
192 B
15 U
C
= =
1262 =
16,08 Btujamft
2 o
F 79
Universitas Sumatera Utara
24. KRISTALIZER K-01
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