VIII - 41
Pra Rencana Pabrik Urea Formaldehyde Concentrate
Jumlah : 1 buah
5. Bak Penampung Air Sanitasi L – 261
Fungsi = Untuk mengalirkan air dari A – 252 ke A - 260 Tipe
= Centrifugal pump
ρ air = 62,43 lb cuft
Rate bahan = 1,983 m
3
jam = 8,3024 gpm = 0,0192 cuft dt
Asumsi aliran turbulen :
Diameter Optimum = 3.9 x qf
0,45
x ρ
0,13
Peter Timmerhaus 4ed, pers. 15 Diameter pipa optimum = 0,694 in
Dipilih pipa 1 in, sch 40 Foust, App. C6a
OD = 1,315 in ID = 1,05 in = 0,0874 ft
A = 0,006 ft
2
Kecepatan aliran, V =
pipa k
volumetri rate
area
2
cuftmnt ft
x
dtmnt 60
1
=
006 ,
1,1496
X
60 1
=
3,1932 ftdt
A - 252 A - 260
L - 261 P
2
V
2
P
1
V
1
A B
∆ Z
reference plane
16 ft
10 ft
10 ft
5 ft
VIII - 42
Pra Rencana Pabrik Urea Formaldehyde Concentrate
= 0,00054 lbft dt berdasarkan sg bahan N
Re
= µ
ρ v
D = 33917,2935 2100
asumsi turbulen benar Dipilih pipa commercial steel
= 0,0017 f = 0,05
Diguakan persamaan Bernoulli : F
x gc
x 2
v gc
g Z
P
2
∑ +
∆ +
∆ +
∆ =
− α
ρ Wf
Perhitungan Friksi berdasarkan Peters Timmerhaus 4
ed
, tabel 1, hal. 484.
Taksiran panjang pipa lurus = 35 ft
Panjang ekuivalen, Le
-
4 elbow 90 ˚
= 4 x 32 x 0,0874 = 8,392 ft
-
1 globe valve = 1 x 300 x 0,0874
= 26,225 ft
-
1 gate valve = 1 x 7 x 0,0874
= 0,6119 ft Panjang total pipa
= 70,2289 ft
Friksi yang terjadi :
1. Friksi karena gesekan bahan dalam pipa.
D Le
v f
2
2 1
× ×
× =
gc F
=
m f
2
lb lb
ft 22,8964
0,0874 2,2
3 70,2289
3,1932 0,05
2 =
× ×
× ×
2. Friksi karena kontraksi dari tangki ke pipa [Peters Timmerhaus 4
ed
, hal 484]
2 v
2 2
2
gc K
F ×
× ×
= α
K = 0,4, A tangki A pipa.
m f
2
lb lb
ft 0,0633
2,2 3
1 2
3,1932 ,4
= ×
× ×
=
VIII - 43
Pra Rencana Pabrik Urea Formaldehyde Concentrate
3. Friksi karena enlargement ekspansi dari pipa ke tangki. 0,1583
32,2 1
2 3,1932
2 v
2 2
2 3
= ×
× −
= ×
× ∆
= gc
F α
m f
lb lb
ft
23,1180 0,1583
0,0633 22,8964
F F
3 2
1
= +
+ =
+ +
=
∑
F F
m f
lb lb
ft
P
1
= P
hidrostatik
= ρ
g h = 62,43 x 1 x 5,455 = 340,5860 lb
f
ft
2
P
2
= 1 atm = 2116,8 lb
f
ft
2
1 atm = 14,7 x 144 lb
f
ft
2
P = P
2
– P
1
= 1776,2140 lb
f
ft
2
; ∆P
ρ = 28,4513 ft lb
f
lb
m
0,1583 32,2
1 2
3,1932 2
v
2 2
2
= ×
× −
= ×
× ∆
gc α
ft lb
f
lb
m
Z
1
= 5,455 ft Z
2
= 16,02 ft ∆Z = Z
2
- Z
1 =
16,02 – 5,455 = 10,565 ft ; ∆Z ggc = 10,565
m f
lb lb
ft
Persamaan Bernoulli : F
x gc
x 2
v gc
g Z
P
2
∑ +
∆ +
∆ +
∆ =
− α
ρ Wf
-Wf = 28,4513 + 10,565 + 0,1583 + 23,1180 = 62,2924
m f
lb lb
ft
Sg campuran Himmelblau : berdasarkan sg bahan = 1
960 3
sg gpm
flowrate p
× ×
− =
Wf h
Perry 6ed ; pers 6-11 ; hal. 6-5.
hp 0,1306
3960 1
8,3024 62,2924
= ×
× =
Effisiensi pompa = 45
Peters Timmerhaus 4ed ; fig. 14-37
VIII - 44
Pra Rencana Pabrik Urea Formaldehyde Concentrate
Bhp =
hp 0,2902
45 0,1306
pompa =
=
η
hp
Effisiensi motor = 80
Peters Timmerhaus 4ed ; fig. 14-38 Power pompa
=
hp 1
0,3628 80
0,2902 pompa
≈ =
=
η
hp
Spesifikasi : Fungsi
: Untuk mengalirkan air dari A – 252 ke A – 260.
Tipe : Centrifugal pump
Bahan : Commercial steel
Rate volumetrik : 8,3024 gpm
Total Dynamic Head : 62,2924 ft lbflbm Effisensi motor
: 80 Power
: 1 hp Jumlah
: 1 buah
6. Pompa Bak Kation Exchanger L – 271
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