my work of heat exchange

8/18/2019 MY WORK of heat exchange

1/29

1

Contents

1.0 DESIGN OF HEAT EXCHANGER ................................................................................................... 3

1.1 INTRODUCTION ............................................................................................................................. 3

1.1.1 Flow Arrangement ....................................................................................................................... 3

1.1.2 Types of Heat Exchangers ............................................................................................................ 4

1.3 Problem statement ............................................................................................................................ 5

1.3.1 Justification .................................................................................................................................. 5

1.4 Chemical engineering design............................................................................................................ 5

1.4.0 Heat Load ..................................................................................................................................... 7

1.4.1 Calculation of area ....................................................................................................................... 8

1.4.2 Choice of tubes ............................................................................................................................ 8

1.4.3 Tube side coefficient calculations ................................................................................................ 9

1.4.4 Shell side coefficient Calculations .............................................................................................. 11

1.4.5 Overall heat transfer coefficient ................................................................................................ 13

1.4.6 Tube side pressure drop ............................................................................................................ 13

1.5 Mechanical design ............................................................................................................................ 15

1.5.1 Design pressure .......................................................................................................................... 15

1.5.2 Design temperature ................................................................................................................... 15

1.5.3 Shell side design ......................................................................................................................... 15

1.5.4 Nozzle design ............................................................................................................................. 16

1.5.5 Channel Cover ............................................................................................................................ 16

1.5.6 Head and closure ....................................................................................................................... 17

1.5.7 Effective length of heat exchanger ............................................................................................ 18

1.5.8 Gasket design ............................................................................................................................. 18

1.5.9 Bolts load estimation ................................................................................................................. 19

1.5.10 Minimum bolt area .................................................................................................................. 19

1.5.11 Flange design ........................................................................................................................... 20

1.5.12 Tube sheet thickness ................................................................................................................ 20

1.5.13 Weight Analysis ........................................................................................................................ 21

1.5.14 Stress analysis .......................................................................................................................... 24

1.5.15 Longitudinal bending stress at mid span, ............................................................................ 261.5.16 Longitudinal bending stress at support, ............................................................................. 26


2/29

2

1.5.17 The resultant axial stress due to bending and pressure, σr ..................................................... 26

REFERENCE ........................................................................................................................................ 28


3/29

3

CHAPTER 1

1.0 DESIGN OF HEAT EXCHANGER

1.1 INTRODUCTIONHeat transfer to and from process fluids is one major operation in chemical process industries.

Heat exchangers are the major devices for this operation. Heat exchanger as the name implies is

used as a medium in which fluids exchange heat without any physical contact. The fluid streams

flow through the heat exchangers and are separated by a conducting wall through which heat can

pass from hot stream to the cold stream without physical contact between the two streams. Heat

transfer in each fluid involves convection and conduction (through the wall separating the two

fluids). The design of heat exchangers involve several factors including; thermal analysis,

structural stress, pressure drop, size and cost.

1.1.1 Flow Arrangement

Heat exchangers are classified according to flow arrangements and type of construction. There are

three primary flow arrangements. These are parallel flow, counter-current flow and cross flow.

In parallel-flow heat exchangers, the two fluids enter the exchanger at the same end, and travel in

the same direction (parallel) to one another to the other side.

In counter flow arrangements, the fluids enter the heat exchanger from opposite directions, flow

in opposite directions and exit in opposite directions.

THi

TCi

figure 1.1 schematic diagram showing parallel

TCf

THf

THiTHf

TCi

TCf

figure 1.2 schematic diagram showing counter


4/29

4

In cross flow, the fluids flow at right angles to each other. This type of flow is found in cross flow

heat exchangers which are normally used for cooling or heating of gases.

The most common among the flow patterns in heat exchangers are the parallel flow and counter

current flow. Heat transfer is more efficient in a counter current flow than a parallel flow under

comparable conditions.

The design of a parallel flow heat is advantageous when the two fluids are required to be brought

to nearly the same temperature. In this design counter current flow would be considered for

efficient heat transfer.

1.1.2 Types of Heat Exchangers

1. Double Pipe Heat Exchangers

These are the simplest kind of heat exchangers used in industries. They are typically used

for small flow rates. The term double pipe refers to a heat exchanger consisting of a pipe

within a pipe usually of a straight-leg construction with no bends. In these devices both hot

and cold fluids flow in concentric tubes.

Advantages

They are cheap to maintain and design

Disadvantage

They have very low efficiencies

Occupies a very large space

2. Shell and tube heat exchangers

The shell and tube is one of the most important heat transfer equipment in the process

industry. It consists of a bundle of tubes enclosed in a cylindrical shell.

Advantages

Used for much larger flow rates than the double pipe heat exchanger.

It can be used for all types of applications.

The configuration and arrangement gives a large surface area in a small volume.

It has a good shape for pressure operation.


5/29

5

It uses well established fabrication techniques.

Shell and tube exchangers can be constructed from a wide range of materials.

3. Fired heaters

4.

Spiral heat exchangers 5. Plate-fin heat exchangers

6. Plate and frame heat exchanger: mostly used for heating and cooling.

7. Agitated vessels

8. Plate-fin exchangers

9. Air cooled: coolers and condensers

Air-cooled heat exchangers include a tube bundle, which generally has spiral-wound fins

upon the tubes, and a fan, which moves air across the tubes and is provided with a driver.

1.3 Problem statement

The main aim of this chapter is to design a heat exchanger that will cool the RBDO at a flowrate

of 769.77kg/h and 185oC to cool RBDO at 160oC using RBO at 80oC to 108oC.

1.3.1 Justification

In the production of soybeans oil from soybean seeds, the refinery process require deodorization

of the olein (efined bleached oil,RBO) at the final stage of the refinery. The RBO is heated to a

temperature of 273oC in the deodorizing chamber for deodorization. The Refined Bleached

Deodorized Oil (refined bleached deodorized oil,RBDO) upon leaving the deodorizing chamber

to storage is at a very high and the temperature needs to be cooled to a lower temperature as well

as the heat energy contained in the RBDO needs to be made used of and not to be discarded.

Shell and tube heat exchanger is suited for higher-pressure and temperature applications .

1.4 Chemical engineering design

General heat transfer equation is given by

, Q U A Δ T

Where Q =Heat transferred per unit time (kW)

A=Heat transfer area (m2)

ΔT Mean temperature difference (˚C) ΔT=ΔTF


6/29

6

ΔT T t T tln (T t.)T t

Where, T1 – Tube side inlet temperature (oC)

T2 – Tube side outlet temperature (oC)

t1 – Shell side inlet temperature (oC)

t2 – Shell side outlet temperature (oC)

M x Cp(t) x (T1-T2) = m x Cp(s) x (t1-t2)…………………………………….

Where, Cp(t) – Liquid specific heat capacity at tube side (kJ/KgoC)

Cp(s) - Liquid specific heat capacity at shell side (kJ/KgoC)

M - Shell side mass flowrate (kg/s)

m - tube side mass flowrate (kg/s)

Where FT is temperature correction factor and it’s a function of R and S

R −− and S −−

ΔT 185108 16080ln 18510816080 ΔT 78.5˚C

t2=108˚C t1=80˚C

T1=185

T2=160˚C


7/29

7

R 18516010880 0.895

S −− 0.267 From Coulson and Richardson’s chemical engineering vol 6, figure 12.19 the graph for correction

factors for heat exchangers when R= 0.895 and S=0.267, Ft=0.97

Hence a heat exchanger with one shell pass and two or more tube passes is suitable for the design.

ΔT=78.5x0.97 =76.1oC

1.4.0 Heat Load

Assumptions

1. Steady state conditions

2. Constant overall heat transfer coefficient

3. Constant heat capacities of both fluids.

4. Heat losses are negligible

Heat loss by hot fluid=heat gained by cold fluid

Q m c Average temperature at shell side 185+1602 173˚C

Heat capacity of oil at 168℃ 2.077 kJkg.K mass flowrate of oil at shell side 769.77 kghr Q=769.77 X 2.077(185 – 160)

= 68.89kw


8/29

8

Therefore, the quantity of heat energy required to be exchanged by the process streams in the heat

exchanger is 68.89kW

1.4.1 Calculation of area

The design of a heat exchanger involves an iterative procedure, from literature a heat transfer

coefficient is assumed for the process streams and it is used in the chemical design calculations.

At the end of the calculations the overall heat transfer coefficient obtained must be higher or equal

to the heat transfer coefficient assumed from literature. If not the calculated heat transfer

coefficient is used in the calculations until it converges. In this report the coefficient of heat transfer

assumed is 551.908W/m2.K

Hence U=100W/m2K Q=68.89kW

Tm=76.9oC

A QU∆T A 68.89 x10 100×76.9 8.958m

1.4.2 Choice of tubes

From Perry’s Chemical engineers handbook the following dimensions where chosen:

Outer diameter of tubeD 34 in0.01905m Inner diameter of tubeD0.620in0.015748m Pitch diameterp 1 . 2 5 × D 0.0238125m Length of tube (L)=2.44m

Number of tubes AπDL

Number of tubes 8.958

π×0.01905×2.44 57.3tubes

Area of one tube π × 0.01905 × 2.44 Area of one tube 0.146 m so for 2 tube passes,tube per pass 572 29tubes


9/29

9

1.4.3 Tube side coefficient calculations

Cross sectional area of one tube πD4

Cross sectional area of one tube π×0.015748

4 1.948×10−m

Tube per pass is 6 tubesFlow Area 29 × 1.948 × 10− 35.649 x10− m Mass velocityG mass flowrateṁflow areaA

Mass velocityG 769.773600×3.385 x10− 37.850 kg/m. s

Tube side linear velocity, u Gρ

Where G is the mass velocity and ρt is the tube side density

Density of oil at 1600C = 832 kg/m3

Tube side linear velocity, u 37.85832 0.045 m/s Re ρ × D × uμ

Viscosity of oil at mean temperature 160˚C;

6.1×10− Pa.s

Re 832×0.01574×0.0456.1×10− R e 9 . 6 6 × 1 0 Pr C × μK

Where Pr = Prandtl number

Kt = thermal conductivity of RBDO (Olein)

Kt = K x w

From Richardson and Coulson, volume 6.thermal conductivity of organic liquids is given by:

k 3 . 5 6 × 1 0−Cp ρM


10/29

10

Where ρ is density of RBDO at tube side temperature832 kgm M is the molecular weight of RBDO920kg/kmol

Cp is the specific heat of RBDO at tube side temperature 2.045 kJkg.K Hence thermal conductivity of RBDO:

k 3 . 5 6 × 1 0− ×2.045×832920 0.059 Wm. K

K

0.059×0.9999

= 0.059 . Pr 2.045 x10 × 6 . 1 × 1 0−0.059 Pr 2.1 x 10

Hence the Nusselt number is calculated as;

Nu h × DK

j × R e × P r. LD 2.440.015748 154.94 R e 9 . 6 6 × 1 0

Reading from fig 12.23 from Richardson and Coulson, volume 6 for Re=9.66x102 and L/Di=155

Jh= 1.8x10-2 where Jh is the tube side friction factor.

h K × J × R e × P r.D

h 0.058×7.5×10− ×2.787×10 ×1.08 x 10 .0.015748 h 177.913 Wm. ˚C


11/29

11

1.4.4 Shell side coefficient Calculations

Mean temperature at shell side 108+802 94˚C Calculating RBO density at shell side,

ρ of RBO at 94˚C 871.48 kgm Calculating specific heat capacity Cp of RBO at 94˚C 1.833 kJkg.K

Cp 1.833 kJkg.K Calculating RBO thermal conductivity at shell side,

K k 3 . 5 6 × 1 0− ×1.833×871.48920

0.056 Wm. K K 0.056×0.998

K 0.056 Wm. K

Viscosity of RBO at 94˚C; T=7.67×10−Pa.s μ 7 . 6 7 × 1 0−Pa.s A P DDlP

Where Pt= tube pitch ,

DO=tube outside diameter,

DS =shell inside diameter, m

lB =baffle spacing, m

P 1.25D 1.25×0.019050.0238125m


12/29

12

From Richardson and Coulson. Volume 6 table 12.4 the values of n and k are obtained for two

tube passes using triangular pitch.k 1=0.249 and n=2.207

D D × Nk

D 0.01905× 2900.249. 0.5624m

For a split ring floating head exchanger from fig.12.10 in Richardson and Coulson, volume 6

bundle clearance=57mm

Shell inner diameter (Ds) = 562.4. +57=0.61949m

l shell diameter

5 0.01290m

A P DDlP 0.02381250.019050.61949×0.012900.0238125 0.001598m mass velocity of RBO G ṁA 771.323600×0.0016

mass velocity of RBO G 134.05 kgm. s

linear velocity at shell side μ Gρ 134.05871.48 0.154m/s

Equivalent diameter, D 1.100.01905 (P 0.917D) Equivalent diameter, D 1.100.01905 0.0238125 0.9170.01905 0.0135m

Re GDμ 134.05×0.01350.154 1.20×10

Pr C p × μ

K 1.833×10 ×7.67×10−

0.056 251.1

Choosing 25% segmental baffle cut and for Re 1.2 × 10, from chart in Richardson andCoulson volume 6, fig 12.29 J 1 . 4 × 1 0− h J × R e × P r. × KD 1.4×10− ×1.20×10 ×0.056×251.1.0.01353 43.07 Wm. K


13/29

13

1.4.5 Overall heat transfer coefficient

1

u 1

h + 1

h + D × l n

DD

2 × K + D

D × 1

h + D

D × 1

h

1u 143.07 + 14000 + 0.01905×ln0.019050.015742 × 5 4 + 0.019050..015748 × 1177.91+ 0.019050.015748 × 14000

U 100.74 Wm. K Since the overall calculated heat transfer coefficient Uo is almost equal to the assumed U the design

is accepted.

1.4.6 Tube side pressure drop

ΔP N × 8 × J × LD +2.5× ρu2 Where Np is the number of tube passes

L is the length of tube

ut is the tube side velocity

ρ is the density at tube side

ΔP 2 × 8 × 1 . 8 × 1 0− ×154.94+2.5 × 832×0.0452 ΔP 41.8kPa Shell side pressure drop

ΔP 8 × J × DD × LL × ρu2 Where Ds is the shell diameterDe is the equivalent shell diameter

L b is the baffle length

L is the length of tube


14/29

14

ρ is density of bulk fluid at shell side

u is velocity of fluid at shell side

ΔP

8 × J

× DD ×

LL ×

ρu2

Δ P 8 × 1 . 4 × 1 0− × 0.619490.01353 × 871.4×0.007672 ΔP1.314kPa Table 1.1 Summary of Chemical Engineering design

Parameter Value

Heat Load 68.89kW

Assumed heat transfer coefficient 100W/m2.K

Log mean temperature 76.1˚C

Correction factor 0.97

Heat transfer area 8.958m2

Tube side design

Tube outer diameter 0.019m

Tube inner diameter 0.016m

Number of tubes 57

Reynolds Number 966

Prandtl number 21

Tube side Transfer coefficient 177.913W/m2

Pressure drop 41.8kPa

Shell side design

Inner Diameter 0.619m

Baffle spacing 0.013mReynolds number 12

Shell side transfer coefficient 43.070W/m2.K

Pressure 1.314kPa

Overall heat transfer coefficient 100.74W/m2.K


15/29


16/29

16

1.5.4 Nozzle design

Nozzle diameter =152.4mm

(For shells with internal diameter between 590.042mm to 736.6m use nozzle diameter of

152.8mm).

Minimum nozzle thickness, tn =××.×− +4

Where

Dn , nozzle internal diameter

Nozzle thickness =.×.×.×.−. + 4 = 4.20mm

Nozzle thickness is 4.20mm≈ 4mm

1.5.5 Channel Cover

The outside diameter of the channel shall be the same as that of the shell. The thickness of the

channel shall be greater of the two values: (i) shell thickness or (ii) thickness calculated on the

basis of the design pressure shown below.

The effective channel cover thickness (IS: 4503 section 15.6.1):

×

where D diameter of cover usually same as outside shell diamter c a factor which is 0.25 when the cover is bolted with fullfaced gaskets and 0.3when bolted with narrow faced or ring type gaskets P is design pressure in N/mm2 and f is allowable stress value in N/mm2 at design temperature

Outside diameter of shell=shell internal diameter + 2(shell thickness)

DC = 619.49+16=635.49mm

t 635.49× √ 0.25×0.2210×100.6 0.1481mm Use tcc = 0.1481+4mm (corrosion allowance) = 4.15mm


17/29

17

1.5.6 Head and closure

The ends of a cylindrical vessel are closed by heads of various shapes. The principal types used

are categorized as either flat end or domed end (hemispherical, ellipsoidal, torispherical).For the

purpose of this design-floating head heat exchanger both the flat end and the torispherical end is

used.

1.5.6.1 Torispherical head

Inside depth of the head (hi) can be calculated as h R R R + +2ri. Where crown radius R i = Ds (shell diameter) = 619.49mm

Knuckle radius ri = 0.06R i=0.06(619.49) =37.1694mm

h 619.49619.49 619.492 619.49+ 619.492 +2×37.1694. 82.93mm Thickness of torispherical head PRW2fj0.2p + C Where W 3 + 3 + ..1.7706mm

Thickness of head 0.22×619.49×1.77062×100.6×0.85 0.2×0.22 +4mm

Thickness of head 5.4mm Use same thickness of shell for head

1.5.6.2 Flat Head

Head thickness, t= C p De

t, head or closure thickness

C p, design constant, dependent on the edge constraint (Sinnott, 2003)

De, nominal plate diameter=619.49mm

Using a full face gasket, bolted cover, take Cp = 0.4


18/29

18

f is the permissible tensile strength of the material

0.4×619.49× .. 11.6 Closure thickness = 11.6+4(corrosion allowance) =16mm

1.5.7 Effective length of heat exchangerE effective heat exchanger length Length of tubes + 2 × h Eeffective heat exchanger length2.44+ 2×0.08293 2.61m

1.5.8 Gasket design

Gaskets are used to make the metal surfaces leak-proof. Gaskets are elasto-plastic materials and

relatively softer than the flange. (IS: 4503)

Gaskets are made from elastic-plastic materials which will deform and flow under load to fill the

surface irregularities between the flanges faces, yet retain sufficient elasticity to take up the

changes in the flange alignment that occur under load. (Sinnott, 2003)

Material: vegetable fibre

Gasket internal diameter = shell internal diameter =619.49mm

Gasket width =30mm (assumed) from Richardson and Coulson minimum width should be 10mm.

Gasket outer diameter =619.49+30= 649.49mm

Gasket factor, m =1.75

Seating stress =7.6 N/mm2 (Sinnott, 2003)

Basic gasket seating, bo =

=15mm

Effective gasket seating b = 2.5 b = 2.5√ 15 =9.68mmEffective gasket seating b is approximately 10mm

Mean gasket diameter, G = 649.49mm


19/29

19

1.5.9 Bolts load estimation

The bolt load due to gasket reaction under atmospheric conditions is given by:

W

y × G × π × b

W 7.36×649.49×π×9.68145.37kN Where Wis the bolt load required to seat the gasket

From W H + H Where

Wm2, minimum required bolt load under the operation condition

H, total pressure force π4 × G × P H π × G × b × m × P W π × G × b × m × P + π4 × G × P

W π×649.49×9.68×1.75×0.22 + π4 ×649.49 ×0.22 W 80.493kN Hence Wm1 is the controlling load since is greater than Wm21.5.10 Minimum bolt area

The minimum bolt cross sectional area (bolt material is carbon steel)

A Wf 145370100.6 1445.029 M16 nominal thread diameter with bolt circle diameter (C b) of 860mm, 32 bolts and 18mm roots

diameter (d br ) are selected.

Corresponding actual bolt circle diameter

A π4 d × number of bolts π4 × 18 ×328143mm


20/29

20

A > A therefore the selected bolts are suitable1.5.11 Flange design

Thickness of the flange is given by,

× + 0 . 3 + {1 . 5 × × ℎ × }−

hG is the radial distance from gasket to bolt circle

B is the flange internal diameter

+ 2× + 12 H π4 ×649.49 ×0.2272.888

Where 0 . 3 + .×.×..×. − 2.4903

ℎ

2 700.49649.49

2 25.5

649.49× 0.222.4903×100.6 +423.25 Hence flange thickness is 23.25mm

1.5.12 Tube sheet thickness

Tube sheet thickness, tf =×

+ C

Where F, tube sheet constant (for tube sheet having straight tubes F=1)

G is the mean gasket width

P is the design pressure


21/29

21

f is the permissible tensile strength

t 619.49×12

× 0.22100.6

+418.48mm 1.5.13 Weight Analysis

Length of heat exchanger=2.44

Shell internal diameter Di=0.61949m

Shell outer diameter Do=0.63549m

Thickness of shell=0.008m

Outer diameter of tube do=0.015748m

Number of tubes Nt = 57 tubes

Density of carbon steel=ρc=7850kg/m3

Density of fluid in tubes=832kg/m3

Weight of shell body, Ws

volume of shell body π4 (D D) × L

volume of shell body π4 0.63549 0.61949 ×2.44 volume of shell body 0.03848m

weight of shell body V × ρ ×9.81

weight of shell body 0.03866 × 7850 × 9.81

weight of shell body 2963.30N Weight of tubes, Wt

V π4 (d d) × L × N


22/29

22

V π4 0.01905 0.015748 ×2.44×290.00686m weight of tubesV × ρ ×9.810.00686×7850×9.81491.75N

Weight of head, Wh volume of head 0.087D volume of head 0.0870.61949 0.02068m

weight of head 0.020985 × 7850 × 9.81 1592.80N Weight of insulation, Wi

w V × ρ ×9.81

V πD × t × L where ti is the thickness of insulationV πD × t ×Lπ×0.61949×0.1×2.440.4749m Density of insulation material=130kg/m3

w 0.4749×130×9.81605.60N Weight of spacers and tie rods, Wsr

W V × ρ × g Rods of length of 3m

V 14 × π × 1 9 × 1 0− × 3 8 . 5 0 5 9 × 1 0−m Rods of length of 2.5m

V 14 × π × 1 9 × 1 0− ×2.57.088×10−m

Total volume V + V 1.5594×10−m W 1.5594×10− ×7850×9.81120.0871N

Weight of baffles, W b


23/29

23

For shell diameter between 152-635mm baffle diameters is given as:

D 16mm+0.8mmtolerance (Sinnott, 2003)

Baffle diameter619.49 1.6+0.8 617.09mm

Cross sectional area of one baffle 14 × π × 0.61709 0.2990m For 25% Baffle

Baffle area remaining 0.75 × 0.2990 0.2243m Total number of tubes through the baffles is 29 with 2 tie and rods

Total area covered by tubes 29 × 14 × (0.015748) 1.674×10−m Effective surface area 0.2243 1.674 × 10− 0.2226 Volume of baffle Effective surface area of baffle × Thickness of baffle

Take thickness of baffle to be 3mm

Volume of baffle 0.2226 × 0.003 6.68 × 10− weight of baffle 6.68 × 10− ×9.81×785051.436N Weight of tube sheet, Wts

weight of tube sheet V × ⍴ × g cross sectional area of tube sheet A 14 × π × d 0.25×π×0.63549m0.4991m

dts covers the whole outer diameter of the shell=0.63549m

Area of tubes 0.09413m Volume of tube sheet A A × t Tube sheet thickness 15.08x10−m


24/29

24

volume of tube sheet 0.49910.09413 ×0.015086.11×10−m weight of tube sheet 6.11 × 10− ×7850×9.81470.52N

Weight of fluid in the tubes, Wft

W V × ⍴ × g volume of mixture in the tubes 14 × π × (0.015748) ×2.444.753×10−m Total volume of mixture in the tubes 29 × 4.75 × 10− 0.0138m

Taking that water fills the head fully at both ends

Inside depth of head=82.93x

10−m

Volume of mixture in closure 14 ×π×0.61949×0.082930.04035m weight of oil in the tubes 0.04054 × 7850 × 9.81 3107.24N

Weight of RBO at shell side, Wfs

Volume of RBOVolume of shellvolume of tubesvolume of baffle Volume of RBO 0.03848 0.00686 1.5594 × 10− 6.724×10− 0.0294 weight of RBO at shell side 0.0311 × 7850 × 9.81 2263.14N

Dead weight, DW

D W W + W + W + W + W + W + W + W + W DW2974.43+491.75+1616.02+607.91+120.09+51.72+262.51+3119.04+

2397.1011672.87N

1.5.14 Stress analysis

4 0.22×619.494 × 8 4.26/


25/29

25

2 0.22×619.492 × 8 8.52/

11672.87

619.498` × 8 0.76/

Longitudinal bending moments at mid-span, ML1

2 × 1 + 2 1 + 43 4

2 11672.87

25.84

, ℎ ℎ 2 0.619492 0.30976 A is the distance from saddle centre line from shell end.

0.4 0.4 × 0.30976 0.12390 5.84×2.44

4× 1 + 20.30976 0.0832.44

1 + 4×0.0833×2.44 4×0.123902.44 78.12

Longitudinal bending moment at supports, ML2

× × 1 + 21 + 43

Where H is the depth of head

5 8 4 0 × 0 . 1 2 3 9 0 × 1 0.123902.44 + 0.30976 0.0832×0.12390×2.441 + 4×0.0833×2.44


26/29

26

563.47 1.5.15 Longitudinal bending stress at mid span, Stress at midspan =

Stress at midspan =×.×.×.

Stress at midspan =0.032N/mm2

1.5.16 Longitudinal bending stress at support, Stress at support =

× C, is an empirical constant, for a completely stiff shell c=1

Stress at support =×.××.×. =0.23N/mm2 (Standard9, 1967)

1.5.17 The resultant axial stress due to bending and pressure, σr

σr, = ±

σr = 4.26±0.023 = 4.282N/mm2

Table 1.2 Summary of Mechanical Engineering design

Parameter Value Parameter Value

Design Pressure 220kPa Design Temperature 203.5˚C

Shell thickness 8mm Nozzle diameter 152.4mm

Shell diameter 619.49mm Nozzle thickness 4mm

Tube sheet thickness 18.6mm Torispherical head

Flange thickness 23.25mm Thickness 8mm

Stress Analysis Inside depth 82.93mm


27/29

27

Longitudinal stress 4.26N/mm2 Dead weight 11.64kN

Circumferential stress 8.52N/mm2 Effective length of heat

exchanger

2.61m

Direct stress 0.76N/mm2 Corrosion allowance 4mm


28/29

28

REFERENCE

Baukal.Jnr, 2000. Heat Transfer in Industrial Conmbustion. New York: CRC Press.

BEE India, B. O. E. E., 2008. Cooling Towers. In: Bureau Of Energy Efficiency. New Delhi: s.n., pp. Pgs 2-

5,11

Branan, C. B., 2005. Rules of Thumb for Chemical Engineers. 4th ed. ed. Boston: Gulf

Professional Publishing.

Cheremisinoff, N. P., 2000. Handbook of Chemical Processing Equipment. s.l.:Butterworth-

Heinemann.

Coulson & Richardson, 2005. Chemical Engineering Design. 4th ed. Oxford: Elsevier

Butterworth-Heinemann.

Couture, P. L., 2010. Thermal-hydraulic Design Of Replacement Cooling Tower For Vermont Yankee

Nuclear PowerStation, Hartford: s.n.

Kent, J., 2012. Handbook of Industrial Chemistry and Biotechnology. In: Handbook of Industrial

Chemistry and Biotechnology. New York: Springer Science Business media.

Lieberman, N. P., 1988. Process Design for Reliable Operations. 2nd ed. Houston(Texas): Gulf

Publishing Co..

Perry, R. H. & Green, D. W., 1999. Distillation. In: Perry's Chemical Engineer's Handbook. 7th

ed. New York: McGraw-Hill Companies, Inc, pp. 35-37.

Peters, M. s. & Timmerhaus, K. D., 1991. Plant Design And Economics For Chemical

Engineers. Fourth Edition ed. New York: McGraw- Hill Co..

Price, R. M., 2003. Distillation. [Online]

Available at: factstaff.cbu.edu/rprice/lectures/distill7.html

Sinnot, R. K., 2005. Chemical Engineering Design. Fourth Edition ed. Oxford: Eslevier

Butterworth-Heinemann.


29/29

Sinnott, R., 2005. Chemical Engineering Design. 4th ed. s.l.:Elsevier Butterworth- Heinemann.

Sinnott, R. K., 2003. Coulson & Richardson's Chemical Engineering Design. Oxford: Elsevier

Butterworth Heineman.

Sinnott, R. K., 2005a. Coulson & Richardson's Chemical engineering series. 4th ed. Oxford:

Elsevier Butterworth-Heinemann.

Sinnott, R. K., 2005b. Coulson & Richardson's Chemical engineering series. 4th ed. Oxford:


Sinnott, R. K., 2005c. Coulson & Richardson's Chemical engineering series. 4th ed. Oxford:


Sinnott, R. K., 2005. Coulson & Richardson's Chemical engineering series. 4 ed. Oxford:


Sinnott, R. & Towler , G., 2013. Chemical Engineering Design Principles, Practice and

Economics of Plant and Process Design.. 2nd ed. Boston: Bulterworth-Heinemann Publications.

my work of heat exchange

Documents