1. INTRODUCTION Definition:
Heat exchangers are devices that transfer or exchange heat from one media to another. It is used either for cooling or for heating purpose.
The mediums flowing inside the heat exchanger may be gas or liquid depending upon the service requirements of the process.
The transfer of thermal energy (heat) can be accomplished in three ways:
Radiation
Convection
Conduction

2. TYPES OF HEAT EXCHANGER
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Shell-and-tube heat exchangers
Air-cooled heat exchangers
Double-pipe heat exchangers
Plate-and-frame heat exchangers

4. TYPES OF HEAT EXCHANGER
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5. TYPES OF HEAT EXCHANGER
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6. Horizontal Tube, Induced-Draft Air-Cooled Heat Exchanger
Air-Cooled Heat Exchangers
Hood or Plenum
Fan Ring
Fan
Return Headers
Inlet Nozzles
Inlet Headers
Outlet Headers
Outlet Nozzles
Tube Bundle
Drive Assembly
Supports
Horizontal Tube, Induced-Draft Air-Cooled Heat Exchanger

7. Double-Pipe Heat Exchanger
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Double-Pipe Heat Exchanger
Shell Cover Gasket
External Fin Pipe
Vent
Shell
Shell Cover
Return Bend (welded)
Drain
Fixed Support
Sliding Support
Twin Flange
Shell End Piece

8. SHELL AND TUBE HEAT EXCHANGER
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These types of heat exchangers are most commonly and widely used in process industries.
Design criteria:
1. TEMA Standards
Tubular Exchanger Manufacturer's Association
2. API 660 (American Petroleum Institute) Standards
Shell and Tube Heat Exchangers for General Refinery Services

9. SHELL AND TUBE HEAT EXCHANGER
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Basic components of SHELL and TUBE heat exchanger are:
Tubes: Provide heat transfer surface
Shell or Body: Enclose the area in which fluids flow
Nozzles: Inlet and outlet for fluid flow
Tube Sheet: Hold the tube in place

10. SHELL AND TUBE HEAT EXCHANGER
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Baffles: Support the tubes in proper position and guide the shell side flow to increase heat transfer
Channel Cover: Allows tube inspection
Pass Divider: Separate the tube side Flow

11. TYPES SHELL AND TUBE HEAT EXCHANGER
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Fixed Tube sheet
Tube sheet is welded to the shell.
Tube bundle is permanently installed.
Used when the temperature range is limited and shell side fouling is limited.
U-Tube or U-Bend:
Has only one tube sheet
Tube bundle can be removed
Used where temperature difference between shell and tube side fluids are high.

12. TYPES SHELL AND TUBE HEAT EXCHANGER
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Floating Head
Tube bundle can be pulled out.
Tube sheet on one side is bolted between channel and shell.
Tube sheet on the other side floats inside the shell and free to move horizontally.
Test ring is required for hydro test.

13. TYPES SHELL AND TUBE HEAT EXCHANGER
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14. FIN FAN COOLER Tubes are Round or Rectangular.
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Tubes are Round or Rectangular.
Fins generally on the outside of the tubes.
For some applications fins may be inside of the tube.
Fins are attached to the tubes by a tight mechanical fit, tension winding, adhesive bonding, soldering , brazing and welding etc.

15. Typical Air-Cooled Heat Exchanger
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Lifting Lug
Air Seal
Tube Keeper (top)
Air Seal
Header
• The RGB specifications for the accent colour palette are as follows:
Blue - Red 75 Green 180 Blue 210
Yellow - Red 255 Green 205 Blue 25
Orange - Red 255 Green 155
Green - Red 165 Green 220 Blue 20
Tube
Air Seal
Nozzle
Header
Fins
Tube spacer
Side Frame
Tube Support (bottom)

16. PLATE HEAT EXCHANGER
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Consist of a number of corrugated metal plates in mutual contact.
Each plate having four ports( Inlet and Outlet).

17. A B Plate-and-Frame Heat Exchanger Aout Bin Nozzle Header
Separating Sheet
Bin
Aout
Nozzle
Header
Corrugated Sheet
Side Bar
Distributor
Effective Length
Effective Width
Heat Transfer Section
Distribution Section
Cout
Ain
Bout B A
STREAM A
Cin

18. PROBLEMS IN HEAT EXCHANGER
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Fouling:
Fouling is the build-up of different kinds of deposits on the parts of an exchanger.
Fouling effectively increases tube wall thickness due to fouling particles.
Pressure drop across exchanger increases.
Due to fouling, time of heat transfer increases.

19. PROBLEMS IN HEAT EXCHANGER
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Tube leakage:
Removal of metal due to fluid flowing in or across the tube.
Can eat away and weaken tube metal which may lead to tube leak
Scale Formation:
Build up of solid impurities on the inside of a tube wall.
Tube Leak:
It affects heat transfer process.

20. CLEANING OF HEAT EXCHANGER
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The method of cleaning is selected depending upon type of deposit and facilities in the plant.
1. High pressure water jet wash:
Hydro jet machine is used .
Water jet pressure around 5000 to PSI.
During hydro jet cleaning all required PPE shall be used as the water jet can easily puncture and tear the skin.

21. CLEANING OF HEAT EXCHANGER
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2. Chemical cleaning:
Involves circulation of hot wash oil or light distillate through tubes or shell.
Cleaning compounds should be compatible with the metallurgy of the exchanger.
Sometimes commercial cleaning solutions are used.
3. Mechanical Cleaning:
Involves tube cleaning using a wire brush or scrappers.
Care should be taken to avoid damaging the tubes

22. HEAT EXCHANGER MAINTENANCE
ACTIVITIES:
1. SCAFFOLDING
2.BLINDING
3.INSULATION REMOVAL
4.DRAINING
5.HEAD COVER REMOVAL
6.PRE-INSPECTION
7.BUNDLE PULLINGOUT/HYDROJET CLEANING
8.TUBE BLOWING
9.SHELL SIDE/TUBE SIDE HYDROTEST/PNEUMATIC TEST
10.IRIS TEST
11. PLUG INSERT/WELD
12.RE-HYDROTEST
13.HEAD COVER BOXUP
14.BLIND REMOVAL

23. 4/21/2017
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