This document provides detailed specifications and calculations for the design of two reactors and associated equipment, including hydrogen quench coils, mechanical designs, nozzles, and heat exchangers. It covers reactor dimensions, design pressures, materials, and thermal properties, along with a fractionator's specifications, performing mass and energy balance calculations. The document encompasses critical calculations for heat load transfer, fluid velocities, pressure drops, and specifications of various components used in the reactor design process.

1. Chapter 5: Equipment Design
Reactor Design:
Ln (Xi/Xf) = K/ LHSV [4].
Xi = inlet concentration (wt. %)
Xf = outlet Concentration (wt. %)
LHSV= Liquid hourly space velocity (hr-1
)
K= Rate constant (hr-1
)
Reactor 1
Average Rate Constant = 2.9818 hr-1
LHSV = 2.91/ Ln (0.88/.12)
= 1.474 hr-1
Volume (m3) = Volumetric flow rate (m3
/hr.) / LHSV
= 8.57 / 1.474
= 5.817 m3
20% Excess volume = (0.2*5.817) + 5.817
= 6.98 m3
Assume L/D = 5
Volume Of reactor = ( *D2
/4)*5D
6.98 = *5*D3/4
D = 1.33 m
L = 5* 1.33
= 6.67 m
Hydrogen quench coil design:
Hydrogen quench gas = 16.9 m/s max
Quench flow rate = 10807.4 kg/hr.
= 120.3 m3
/hr.
= 0.033427 m3
/sec
Area = 0.033427/16.9
=.00148 m2

2. *D2
/4 = 0.001978
D = 0.05 m
= 5 cm
Select 2 inch Schedule 160 pipe of ASME B31.3 [12].
Nominal size = 2 inch
Outside diameter = 2.375 inch
Wall thickness = .344 inch
Weight = 7.46 lb/ft.
Reactor 2
Average Rate Constant = 2.9818 hr-1
LHSV = 2.91/ Ln (0.86/.011)
= 0.67 hr-1
Volume (m3
) = Volumetric flow rate (m3
/hr.) / LHSV
= 54.87 / 0.67
= 8.190 m
20% Excess volume = (0.2*83.4) + 83.4
= 9.828 m3
Assume L/D = 5
Volume Of reactor = ( *D2
/4)*5D
100 = *5*D3
/4
D = 1.58 m
Length of reactor = 7.9 m
Hydrogen quench coil design:
Hydrogen quench gas = 16.9 m/s max
Quench flow rate = 3339.6 kg/hr.
= 37.1 m3
/hr.
= .0103 m3
/sec
Area = 0.0103/16.9

3. =0.000609 m2
*D2
/4 = 0.000309
D = 0.0278 m
= 2.78 cm
= 3 cm
Select 1 ¼ inch schedule 160 pipe of ASME B31.3 material
Nominal size = 1 ¼ inch
Outside diameter = 1.6 inch
Wall thickness = 0.25 inch
Weight = 3.76 lb/ft.
Mechanical Design:
Reactor – 1
Maximum Allowable stress = 13100 psi for SA 340 material [8].
Design Pressure = 173.4 + 17.3
= 190.74 kg/cm2
Shell thickness t= PD/ (2fJ-P)
= (190.74*1.33)/ (2*921*0.85-190.74)
= 0.184 m
= 18.4 cm
Design of heads:
Hemispherical head design [2].
t = PD/4fJ
= (190.74*133)/ (4*0.85*921)
= 8.1 cm
Reactor – 2
Shell thickness t = PD/ (2fJ-P)
= (190.74*1.58)/ (2*921*0.85-190.74)
= 0.219 m

4. = 21.9 cm
Hemispherical head design
t = PD/4fJ
= (190.74*158)/ (4*.85*921)
= 9.62 cm
Nozzle design
Allowable stress (psi) = 13100
Outside diameter of nozzle (in) = 6
Nominal wall thickness of nozzle (in) = 0.65
Nozzle corrosion allowance (in) = 0.078
Under tolerance allowance = 12.5%
Interior Pressure (psi) = 2390
UT (in) = 0.65*0.125
= 0.08125
Rn (in) = Do/2 – (Twall – C.A) + UT
= (6/2)-(0.65-.078)+0.08125
= 2.5
Treq (in) = 0.592
Inside diameter = 4.81586 in
Select 1 ¼ Cr- 1 Mo Material reactor
Select ASME B 16.5 material class 2500 Flanges [9].
Select nominal pipe size = 5 inch
Flange Diameter = 16 ½ inch
Number of bolts = 8
Bolt Diameter = 1 ¾ inch
Bolt Circle Diameter = 12 ¾ inch
Gasket
Inner ring inside diameter = 5 1/16 inch

5. Sealing Element (inside diameter) = 5 ¾ inch
Outside Diameter = 7.31 inch
Heat Exchanger Design
Chemical API S.G Flow rate
(kg/hr.)
Temp
In.(O
C)
Temp out
(O
C)
VGO 14.09 0.9719 5000 t1 = 165 t2 = 200
Diesel 26.89 0.8933 1981.67 T1 = 285 T2 = 120
Heat Capacity of Diesel = 2.51 KJ/kg K
Heat Load, Q = mCp T = m*Cp*(T1 – T2)
= 1981.67*2.51*(285-120)
= 784741.3 KJ/hr.
This Heat load will transfer to Crude.
Heat Capacity of VGO = 2.33 KJ/kg K
Q = m*Cp (t2 – t1)
784741.3 = 5000*2.33*(t-165)
t2 = 232.2443 o
C
For counter-current flow
TLMTD = ((T1 - t2) – (T2 - t1)) / ln ((T1 - t2) / (T2 - t1))
= ((285 – 232.2) – (165-120)) / ln ((285 – 232.2)/(165 – 120))
= 48.7 o
C
For Heavy hydrocarbon oils
Assume overall coefficient U = 190 W/m2 o
C

6. Q = UA Tm
Provisional area
A = Q/U T = (784741.3*1000/3600) / (190*48.7) = 84.67 m2
Choose 20 mm o.d., 16 mm i.d., and 4.88 m long tubes, MOC = cupro-nickel
Allowing for tube-sheet thickness, take
L = 4.83 m
Area of one tube = 4.83*20*10-3
* = 0.303 m2
Number of tubes, Nt = 84.67/0.303 = 262.48
As the shell-side fluid is relatively clean use 1.25 triangular pitch.
Shell Side = Diesel
Tube Side = VGO
For 2 Pass, K1 = 0.249, n1 = 2.207
Bundle diameter Db = do (Nt / K1)1/n1 = 20 (262 / 0.249)1/2.207
= 468.5 mm
Use a split-ring floating head type.
From Figure Shell-bundle clearance, bundle diametrical clearance = 65 mm
Shell diameter, Ds = 468.5 + 65 = 533.5 mm
Tube-side coefficient
Mean Crude temperature = (165 + 232.2)/2 = 198.62 o
C
µ = 3.01 cp = 3.01*10-3
Pa-s
K = 0.126 W/m o
C
Cp = 2.33 KJ/Kg K
Tube cross-sectional area, = ( /4) *di2
= (Pi/4)*162
= 201 mm2
Tubes per pass = 204/2 = 102

7. Total flow area, A = 102*201*10-6
= 0.02 m2
Crude mass Velocity = m/A = (5000 / 3600) / 0.02 = 67.75 Kg/m2
s
Density of Crude = 971.9 Kg/m3
Crude linear Velocity = 67.75 / 971.9 = 0.0697 m/s
Re = udi/µ = (971.9*0.0697*0.016) / (3.01*10-3
) = 360.17
Pr = Cp µ/ Kf = (2.33*1000)*(3.01*10-3
) / 0.126 = 54.94
Re < 4000, Use Dittus-Bolter equation
Nu = 1.86(RePr)0.33 (de/L)0.33
Nu = 1.86*((463.7*42.67)^0.33)*((0.016/0.00488)^0.33)= 72.03
hi *di/kf = 72.03
hi = 72.03*0.126 / 0.016
hi = 567.24 W/m2 o
C
Viscosity correction factor
hi (tw – t) = U(T – t)
tw – 182.5 = (200 / 567.24)*(202.5 – 198.62)
tw = 183.86 o
C
So, µw = 1.066 cp
(µ/ µw)0.14
= (2.33 / 1.066)0.14
= 1.15
hi = 567.24*1.15 = 652.3 W/m2 o
C
Shell-side coefficient
Choose baffle spacing, lB = Ds/5 =533.5 / 5 = 106.7 mm.
Tube pitch, Pt = 1.25*20 = 25 mm

8. Cross-flow area, As = ((Pt – do)/ Pt)*Ds*lB = ((25-20) / 25) * 106.7 *533.5 *10-6
= 0.011
m2
Mass Velocity, Gs = (1981.67 / 3600) / 0.011 = 46.78 Kg/m2
s
Equivalent dia., de = (1.10/do)*(Pt
2 – 0.917do2) = (1.10/20)*(252
– 0.917*202
) = 14.2
mm
Mean Shell side Temp. = (285+120)/2 = 202.5 o
C
Diesel Density = 893.3 Kg/m3
Viscosity = 0.96 cp
Cp = 2.51 KJ/kg o
C
kf = 0.126 W/m o
C
Re = Gs*de/µ = (46.78*14.2*10-3
) / (0.96*10-3
) = 692.11
Pr = Cp µ/ Kf = (2.51*1000)*(0.96*10-3
) / 0.126 = 19.12
From graph of heat transfer factor jh vs. Re
Choose 25% baffle cut
jh = 0.02
Nu = jh *Re*Pr1/3 (µ/ µw)0.14 = (0.02)*692.11*(19.12)1/3
*(1.15)0.14
= 53.2986
hs *de/kf =53.2986
hs = 53.2986*0.126/ (14.2*10-3
)
= 472.9 w/m2 o
C
Overall Coefficient
Thermal conductivity of cupro-nickel alloys = 50 W/m o
C
Fouling coefficients for Heavy hydrocarbons, hod = hid = 2000 W/m2 o
C
(1/Uo) = (1/ho) + (1/hod) + ((do ln (do/di)) / 2kw) + (do/ (di*hid)) + (do/ (di*hi))

9. = (1/472.9) + (1/2000) + ((0.020*ln (20/16))/ 2*50) + (20/ (16*2000))
+ (20/ (16*652.3))
1/Uo = 0.0052
Uo = 192.2961 w/m2 o
C
Well above assumed value of 190 w/m2 o
C
Pressure drop
Tube-side
Re = 463.69
From figure of friction factor jf vs. Re
jf = 0.025
Pt = 8 jf (L’/di) ( *ut2/2) (µ/ µw)-0.14
= 2[8*(0.025)(4.83*1000/16) + 2.5]*(971.9*0.06912
/ 2)* (1.15)-0.14
= 292.4 N/m2
This is acceptable.
Shell side
Linear Velocity = Gs / = 44.9 / 893.3 = 0.05 m/s
Re = 664.39
From figure of friction factor jf vs. Re
jf = 0.078
Pt = 8 jf (Ds/de)*(L/lB)*( *ut2/2)
= 8*(0.078)*(544.2/14.2)*(4.83*1000/157.2)*(893.3*0.052
/ 2)*

10. = 83004.54 N/m2
= 83 KPa =
This is acceptable [6].
Fractionator Design
Fig. 5.1: Chemcad fractionator Flow sheet

11. No. of stages 32
Calculate condenser duty kcal/h
-
2.43E+06
Calculate main column P drop (atm) 0.13
Calculate condenser pressure (atm) 3
Bottom mass holdup kg 0.9072
Bottom liq. level m 0.3048
Calc. Reflux ratio 0.3447
Calc. Reflux mole (kmol/h) 62.7203
Calc. Reflux mass (kg/h) 1606.068
Tray Specifications:
Tray no. 10
Tray temp C 145.85
Configuration:
No. of strippers 1
Total No. of stages 30
Press of column top atm 1.5
Column pressure drop atm 0.13
Bottom steam rate 138
(kmol/h)
Steam temperature C 265
Steam pressure atm 5
1st feed stage # 28
Side Strippers:
Stripper no. 1
No. of stages 2
Draw from stage 25
Return to stage 23
Steam flow rate
(kmol/h) 22
Steam temp C 167.85
Steam pressure atm 7
Bot. vol. flow m3
/h 2

12. FLOW SUMMARIES:
Stream No. 1 2 3 6
Stream Name feed Top L. Naphtha Bottom
Temp C 237.85 51.85 141.8252 186.7882
Pressure atm 2 3 1.6068 1.63
Enthalpy kcal/h -89480 1.15E+07 -29522 25526
Vapor mole fraction 0.76154 0 0 0
Total kmol/h 37.4776 181.9822 8.1645 7.3308
Total kg/h 5184.11 4659.993 1566.36 1840.154
Total std L m3
/h 6.9699 5.5998 2 2.2526
Total std V m3
/h 840.01 4078.89 183 164.31
Flow rates in kg/h
Water 0 2879.037 1.9216 1.4391
Methane 90 90 0 0
N-Butane 250 249.9995 0.0005 0
N-Heptane 650.0001 649.6669 0.3295 0.0036
NBP111C 0 0 0 0
NBP137C 287.4377 285.9348 1.4887 0.0141
NBP156C 144.622 142.1405 2.4575 0.024
NBP170C 159.0759 152.955 6.0577 0.0631
NBP183C 180.2144 163.4447 16.5927 0.1755
NBP192C 82.4432 43.7147 38.5705 0.1571
NBP198C 86.2804 3.0244 83.0051 0.2512
NBP204C 90.137 0.0725 89.6696 0.3946
NBP209C 94.0158 0.0016 93.3924 0.6216
NBP215C 97.9116 0 96.9284 0.9832
NBP220C 101.8276 0 100.266 1.5616
NBP226C 77.9706 0 76.1355 1.8351
NBP232C 58.1942 0 56.0845 2.1097
NBP253C 811.2737 0 671.1692 140.1045
NBP289C 1369.731 0 230.353 1139.378
NBP325C 235.51 0 1.9258 233.5842
NBP384C 317.4653 0 0.0122 317.4532

13. Tray Design:
Tray Vapor Liquid Space NPass Diameter %flood
Presure
Drop
kg/h kg/h cm m atm
2 9767.95 5107.96 60.96 1 1.07 71.23 0.0064
3 11102.06 6442.07 60.96 1 1.07 78.83 0.0073
4 11395.58 6735.59 60.96 1 1.22 61.53 0.0056
5 11464.38 6804.39 60.96 1 1.22 61.77 0.0056
6 11479.46 6819.47 60.96 1 1.22 61.78 0.0056
7 11479.79 6819.8 60.96 1 1.22 61.71 0.0056
8 11475.16 6815.17 60.96 1 1.22 61.63 0.0056
9 11469.4 6809.41 60.96 1 1.22 61.53 0.0056
10 11463.07 6803.08 60.96 1 1.22 61.43 0.0056
11 11461.73 6801.74 60.96 1 1.22 61.34 0.0056
12 11455.97 6795.97 60.96 1 1.07 79.98 0.0077
13 11449.24 6789.25 60.96 1 1.07 79.87 0.0077
14 11442 6782.01 60.96 1 1.07 79.76 0.0077
15 11432.95 6772.95 60.96 1 1.07 79.64 0.0076
16 11421.23 6761.23 60.96 1 1.07 79.51 0.0076
17 11406.52 6746.53 60.96 1 1.07 79.37 0.0076
18 11387.6 6727.61 60.96 1 1.07 79.22 0.0076
19 11362.86 6702.86 60.96 1 1.07 79.04 0.0076
20 11328.53 6668.53 60.96 1 1.07 78.83 0.0075
21 11272.76 6612.76 60.96 1 1.07 78.54 0.0075
22 11164.78 6504.78 60.96 1 1.07 78.09 0.0074
23 10032.12 6248.22 60.96 1 1.07 69.67 0.0063
24 9725.1 5941.2 60.96 1 1.07 68.89 0.0062
25 9237.21 3407.19 60.96 1 1.07 67.76 0.0054
26 9009.91 3179.88 60.96 1 1.07 67.28 0.0054
27 8837.86 3007.84 60.96 1 1.07 66.91 0.0054
28 4548.81 3902.89 60.96 1 0.91 61.92 0.0054
29 4017.36 3371.44 60.96 1 0.91 57.73 0.0053
30 4017.36 1840.15 60.96 1 0.91 57.37 0.0051
31 648.35 1818.38 60.96 1 0.46 38.47 0.005
32 648.35 1566.36 60.96 1 0.3 79.06 0.0074

14. Tray No. 2
Tray Loadings Vapor Liquid
9767.95 kg/h 5107.958 kg/h
4687.663 m3/h 7.235 m3/h
Density 2.084 kg/m3 705.969 kg/m3
System factor ................ 1
Valve type : V-1
Valve material : S.S.
Valve thickness ................ 12 gauge
Deck thickness ................ 14 gauge
Tower internal diameter ................ 1.067 m
Tray spacing ................ 60.96 cm
No. of tray liquid passes ................ 1
Downcomer dimension
Width
cm
Length
cm Area m2
Side 10.16 62.63 0.043
Avg. weir length ................ 62.63 cm
Weir height ................ 5.08 cm
Flow path length ................ 86.36 cm
Flow path width ................ 93.473 cm
Tray area ................ 0.894 m2
Tray active area ................ 0.807 m2
% flood ................ 71.225
Hole area ................ 0.153 m2
Approx # of valves ................ 129
Downcomer clearance ................ 4.445 cm
Downcomer backup ................ 15.75 cm
Downcomer residence time ............... 3.393 sec
Downcomer velocity ............ 0.046 m/sec
Liquid holdup ................ 23.263 kg
Design pressure ................ 1.5 atm
Joint efficiency ................ 0.85
Allowable stress ................ 932.23 atm
Corrosion allowance ................ 0.079 cm
Column thickness ................ 0.159 cm
Bottom thickness ................ 0.953 cm

15. Cost estimations:
Column diameter m 1.0668
Tray space m 0.6096
Thickness (top) cm 0.2381
Thickness (bot) cm 5.08
Total purchase $ 288827
Total installed $ 866481
Shell weight kg 14135
Column purchase $ 288827
Column installed $ 866481
Cost of shell $ 193384
Cost of trays $ 21412
Platform & ladder $ 12383