Table of Content Introduction of heat exchanger. Design of Coolers.

Table of Content

• Introduction of heat exchanger.

• Design of Coolers.

Continue

• Introduction of fixed bed reactors.

• Design of reactors.

Heat exchanger

• Heat exchanger is a device designed to transfer heat from one fluid (liquid or gases) to another where the two fluids are physically separated.

• In our design we assumed that the cooler which used is a shell and tube heat exchanger.

• The advantages of shell and tube heat exchanger are:

1. The configuration gives a large surface area in a small volume.

2. Can be constructed from a wide range of materials.3. Easily cleaned.

Assumptions:

1- Use shell and tube heat exchanger, two shell and four tube passes.

2- Assume the outer, the inner diameter and the length of the tube.

Design procedure of shell and tube heat exchanger:

1. Heat load ,(kW)

2. Log mean Temperature, (˚C)

Where - Inlet shell side fluid temperature (˚C). - Outlet shell side fluid temperature (˚C). - Inlet tube side temperature (˚C).- Outlet tube temperature (˚C).

)(

)(ln

)()(

12

21

1221

tT

tTtTtT

Tlm

TmCQ ph

3.Provisional Area, (m2)

Where - True temperature difference.

- ( Temperature correction factor)

4. Area of one tube, m2. Where-Outer diameter (do), (mm)

-Length of tube (L), (mm)

- Number of tubes = provisional area / area of one tube

mTU

QA

mT

lmtm TFT tF

LdA o

5. Overall heat transfer coefficient, W/m2 oC.

Where- Outside coefficient (fouling factor).- Inside coefficient (fouling factor).

6. Bundle diameter.

Where- Outside diameter (mm).- Number of tubes.-K1 & n1 are constant.

ii

o

id

oi

o

odo hd

d

hdi

d

kw

d

dLNd

hhU

11

2

1110

0

odh

idh

0d

tN

7. Shell diameter.

8. Shell thickness.

Where- t: shell thickness (in).

- P: internal pressure (psig).

- ri: internal radius of shell (in).

- EJ: efficiency of joints.

- S: working stress (psi).

- Cc: allowance for corrosion (in).

ClearanceDD bs

cJ

i CPSE

t

6.0

Pr

Results

Equipment name Cooler

Objective To cool the feed stream and prepare

it to inter the separator Equipment Number E-103

Type Shell and tube heat exchanger Location After the reactor (CRV-100)

Utility Sea water

Material of construction Carbon steel

Insulation Quartz wool – Glass wool Shell Side Inlet temperature (oC) 200

Shell Side Outlet temperature (oC) 40

Tube Side Inlet temperature (oC) 35

Tube Side Outlet temperature (oC) 94.439

Heat load (kW) 1169.316

Overall heat transfer coefficient (W/m2 oC) 300

LMTD (oC) 32.972

Number of tubes 470

Tube length (m) 4.88

Tube diameter (m) 0.63354

Heat Exchanger area (m2) 144.161

Thickness (mm) 18.5

Shell diameter (m) 0.69554

Number of tube Rows 4

Cost $ $93,200

Reactors• In our plant, the reactor used is catalytic fixed bed reactor.

• catalytic fixed bed reactor is a cylindrical tube, randomly filled with catalyst particles which may be spheres or cylindrical pellets to optimize flow distribution patterns and to alternate the speed of reaction.

• It is used very commonly in industry because it has many valuable features such as:

1. It gives the highest conversion.2. Efficient heat transfer.3. Temperature uniformity.4. Less severe pressure drop.

Design Procedure of Catalytic Fixed Bed Reactor

For CH4+CO22CO+2H2

1. Get reaction rate constant (k).

2. Calculate the concentration for carbon dioxide.

3. Calculate the rate of reaction.

4. Calculate the weight of catalyst.

AA kCr

0A

A

F

r

dW

dx

5. Calculate the volume of reactor.

6. Assume the ratio of length to diameter of reactor (L / D).

7. Calculate the height of reactor.8. Calculate the flow rate of heating the

reactor. 9. Calculate the thickness of reactor.10. Calculate the cost.

*)1()(

WcolumnV

ResultsEquipment name reactor

Objective To convert CO2 and CH4 to CO

Equipment Number ERV-100 (flow sheet 1)

Type Catalytic fixed bed reactor

Location After Furnace F-100


Insulation Quartz wool – Glass wool

Operating temperature (oC) 800

Operating pressure (psia) 14.696

Feed Flow Rate (mole/s) 52.174

Conversion 92.22

Results

Weight of Catalyst (Kg) 1000

Height of Bed/s (m) 1.9409

Volume of reactor (m3) 0.4187

Catalyst Type Ni-Al2O3

Catalyst Density (Kg/m3) 3980

Reactor Height (m) 3.4261

Reactor Diameter (m) 0.4852

Reactor thickness (m) 10

CO2 Flow rate for heating reactor kg/h 13631.388

Cost $ $32300


Objective To convert CO2 and CH4 to CO

Equipment Number ERV-100 (flow sheet 2)


Location After Furnace F-100






Conversion 91.58

Results

Weight of Catalyst (Kg) 1000



Catalyst Type Ni-Al2O3




Reactor thickness (m) 10

CO2 Flow rate for heating reactor kg/h 13792.75

Cost $ $32300

Equilibrium Reactor 2 (flow sheet 2)

CO+2H2CH3OHAssumption:

• Set Hydrogen as a limiting reactant.

• The porosity of the catalyst Φ=0.3

• the ratio of length to diameter (L/D)=4


1. Get reaction rate constant (k).

2. Calculate the concentration.



0A

A

F

r

dW

dx

)(AB

CAA CKeqC

CCkr



7. Calculate the height of reactor.8. Calculate the flow rate of cooling the


*)1()(

WcolumnV


Objective To convert CO and H2 to methanol

Equipment Number ERV-101 (flow shee2)


Location After cooler E-101






Conversion 30.11

Results

Weight of Catalyst (Kg) 2323.88



Catalyst Type CuO/ZnO/Al2O3




Reactor thickness (m) 57.9

H2 Flow rate for cooling reactor kg/h 13792.75

Cost $ $95,300


CO+CH3OHCH3COOH1. Get reaction rate constant (k).

2. Calculate the partial pressure for CO and CH3OH.



0A

A

F

r

dW

dx

BAA PkPr



7. Calculate the height of reactor.8. Calculate the flow rate of cooling the


*)1()(

WcolumnV


Objective To convert CO and CH3OH to CH3COOH

Equipment Number CRV-101 (flow sheet 1)






Operating pressure (psia) 517


Conversion 90

Results




Catalyst Type CH3I

Catalyst Density (Kg/m3) 2278.9





Cost $ $12,800


Objective To convert CO and CH3OH to CH3COOH

Equipment Number CRV-100 (flow sheet 2)






Operating pressure (psia) 515


Conversion 90

Results




Catalyst Type CH3I

Catalyst Density (Kg/m3) 2278.9





Cost $ $11,200

Thank you for listeningThank you for listening

Table of Content Introduction of heat exchanger. Design of Coolers.

Documents

Transcript of Table of Content Introduction of heat exchanger. Design of Coolers.