18. reboiler oke

6.18. Reboiler (RB-01)Fungsi : Memanaskan kembali bottom product Distilation Coulumn

Tipe: Shell and TubeGambar:Fluida Panas: Steam

W= 5.494,330 kg/jam = 12.112,909 lb/jam

T1= 330 oC

= 626 oF

T2= 170 oC

= 338 oFFluida Dingin: Gliserol

W= 3.041,924 kg/jam = 6.706,286 lb/jam

t1= 109 oC

= 228,2 oF

t2= 287,8 oC

= 550,04 oFPerhitungan:

1. Beban Panas Rb-01, QQ = 6.283.864,944 kJ/jam = 5.956.041,993 Btu/jam 2. Log Mean Temperature Difference (LMTD)Fluida Panas (oF)Fluida Dingin (oF)Selisih

626Suhu tinggi55076

338Suhu rendah228,2109,80

Selisih-33,84

LMTD= = 91,843 oFR=

= 0,895

S = = 0,8090Ft

= 0,74

(Fig.19 Kern, page 829)

(3 Shell Pass 6) t = 67,964 oF3. Tc = Tavg = 482 oFtc = tavg =389,12 oF

UD = 100- 500 cold fluid more than 2 cp , dipilih = 150 Btu/hr.ft2.oF

(Table 8 Kern, page 840)

A =

A= 432,334 ft2

Karena A > 200 ft2, maka dipilih HE jenis Shell and Tube Exchanger. Rencana Klasifikasi

Tube Side :

Panjang tube (L)

= 10 ft

= 120 in

Outside Diameter (OD)= 1 in

BWG

= 14

Pass

= 6

a"

= 0,2618

(Table 10.Kern)

Jumlah tube (Nt)

=

Tube sheet

= 1,25 triangular pitch

Nt

= = 165,14

Dari Tabel 9 Kern, diperoleh Nt yang mendekati yaitu 164

- Koreksi UD

A= Nt x L x a''

= 432,334 ft2

UD =

UD = (5.956.041,993 Btu/jam) / (432,334 ft2 x 91,843)

= 150 Btu/jam.ft2.oF

(koreksi memenuhi)karena nilai Ud sama dengan nilai Ud asumsi, maka data untuk Shell.

Shell side :

ID

= 21 1/4 in

Baffle Space (B) = (ID/2) = 10,625 in

Pass (n)

= 3

Pt

= 1 1/4 in

(Table 9 Kern, Page 841)Fluida panas (Steam) : Tube Sidea. Flow area per tube (a't)= 0,546 in2Total flow area (at)

= Nt x a't / 144 x n

= 0,209 ft2b. Laju alir steam, Gt

= W / at

= 12.112,909 lb/hr / (0,209 ft2 )= 58.035,031 lb/(hr) (ft2)c. Bilangan Reynold, Ret

Pada tavg

= 482 oF

Viskositas ( )

= 0,02147 cp = 0,052 lb/ft hr

ID

= 0,834 in= 0,070 ft

Ret

= D x Gt /

= 77.629,647

d. L/D

= 10 ft/ 0,070 ft

= 142,857

jH

= 201

(Fig. 24 Kern, page 834)e. Pada tavg

= 482 oF

k = 0,0918 Btu/hr ftoF

Cp = 8,709 Btu/lboF

Prandl Number ( Pr ) =

= 4,929

Dengan (/w) = 1 untuk bahan kimia kecuai untuk hidrokarbon.

Koreksi viskositas diabaikan karena tidak significant, maka didapat :

hi = 451,833 Btu/hr ft2oF

hio = hi (ID / OD)

= 451,833 Btu/hr ft2oF (0,834 in/ 1 in)

= 376,829 Btu/hr ft2 oF

Fluida dingin: Shell Side

Suhu rata-rata

= 396 oFBaffle spacing (B)

=7,63 inClerance (C')

=pitch OD

= 1 1/4 in 1 in

= 0,25 ina. Luas area laluan (as)=(ID x C' x B) / (144 Pt)

= 0,314 ft2b. Laju alir, (Gs)

= W / as

= 6.706,286 lb/h / (0,314 ft2 )

= 21.385,857 lb/hr ft2c. Pada Tavg

= 389 0F

Viskositas (u)

= 0,0033 cp

= 0,008 lb/ft hr

Diameter ekivalen (De)= 0,72 in

(Fig. 28 Kern, page 838)

= 0,060 ft

Maka Reynold Number (Res)= D x Gs /

= 160.675,113JH

= 800

(Fig. 28 Kern, page 838)d. Pada Tavg

= 389 0F

k

= 0,916 Btu/hr ft0F

Cp

= 18,650 Btu/lb 0F

Prandl Number ( Pr ) =

= 0,546

f.

Koreksi viskositas diabaikan karena tidak signifikan, maka didapat :

ho = 6.666,099 Btu/hr ft20F

4.Clean overall coefficient, Uc

Uc= (hio x ho) / (hio + ho)

= (376,829 Btu/hr ft2 oF x 6.666,099 Btu/hr ft2 oF) / (376,829 + 6.666,099)Btu/hr ft2 oF

= 356,667 Btu/hr ft2 oF5.Dirt factor, Rd

Rd = (Uc - UD ) / (Uc x UD)

= ( 356,667 - 150 ) Btu/hr ft2 oF / ( 356,667 x 150 ) Btu/hr ft2 oF

= 0,004

PRESSURE DROP

Tube side

1.Untuk NRe = 77.629,647

Faktor friksi ( f ) = 0,00018


s

= 1,1050

2.Pt

=

= 0,00151 psi

3.Gt

= 58.035,031 lb/(hr) (ft2)

V2/ 2g= 0,001


Pr

= (4n / s) (V2/ 2g)

= 0,0217 psi

4.PT

= Pt + Pr

= 0,00151 psi+ 0,0217 psi

= 0,0232 psi

Shell Side

1) Faktor friksi

Res

= 160.675,113

Faktor friksi ( f )= 0,002

(Fig. 29 Kern, page 839)2) Number of cross, (N+1)

N + 1

= 12 L / B

= 12 (120 in) / 10,625 in

= 135,529

Ds

= ID / 12

= 21 1/4 in / 12

= 1,771 ft

s

= 0,82

3) Ps

= = 0,0855 psiIDENTIFIKASI

Nama AlatReboiler

Kode AlatRb 01

Jumlah1 buah

OperasiKontinyu

FungsiMemanaskan kembali bottom product Distilation Coulumn (DC-01)

DATA DESIGN

TipeShell and Tube

Bahan KonstruksiCarbon steel

Rd Calculated0,004

UC356,667

UD150

Shell SideTube Side

ID=21 1/4 inLength=10 ft

B=10,625 inOD BWGPitch==1 in141 1/4 in tri

Passes=3Passes=6

Ps=0,0855 psiPt=0,0232 psi

EMBED Visio.Drawing.11

EMBED Equation.3

EMBED Equation.3

EMBED Equation.3

EMBED Equation.3

EMBED Equation.3

EMBED Equation.3

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_1200055319.unknown

18. reboiler oke

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