Heat Exchanger - Design, Construction and Working

1. By: Baher EL ShaikhBy: Baher EL Shaikh
Mechanical EngineerMechanical Engineer
EMetahnexEMetahnex
1

2.  Shell and tube heat exchangers are one of the
most common equipment found in all plants
 How it works?
2

3.  Heat Exchanger
 Cooler
 Heater
 Condenser
 Reboiler
Both sides single phase and process stream
One stream process fluid and the other cooling water or air
One stream process fluid and heating utility as steam
One stream condensing vapor and the other cooling water or air
One stream bottom stream from a distillation column and the other a hot utility
or process stream
 Classification according to service .
3

4.  Code
 Standard
 Specifications
Is recommended method of doing something
ASME BPV – TEMA
is the degree of excellence required
API 660-ASME B16.5–ASME B36.10M–ASME B36.19-ASME B16.9–ASME B16.11
Is a detailed description of construction, materials,… etc
Contractor or Owner specifications
4

5. 2- Channel
3- Channel Flange
4- Pass Partition
5- Stationary Tubesheet
6- Shell Flange
7- Tube
8- Shell
9- Baffles
10- Floating Head backing Device
11- Floating Tubesheet
12- Floating Head
13- Floating Head Flange
14 –Shell Cover
1- Channel Cover
5

6. 6

7.  Front Head TypeFront Head Type
A - Type B - Type C - Type
7

8.  Shell TypeShell Type
E - Type F - Type
J - Type
K - Type
8

9.  Rear End Head TypesRear End Head Types
M - Type S - Type T - Type
Fixed Tubesheet Floating Head Pull-Through
Floating Head
9

10.  U-Tube Heat ExchangerU-Tube Heat Exchanger
 Fixed Tubesheet Heat ExchangerFixed Tubesheet Heat Exchanger
 Floating Tubesheet Heat exchangerFloating Tubesheet Heat exchanger
10

11. AES
11

12. AKT
12

13.  Terminology
 Design data
 Material selection
 Codes overview
 Sample calculations
 Hydrostatic test
 Sample drawing
13

14.  ASME
 TEMA
 API
 MAWP
 MDMT
 PWHT
 NPS – DN – NB – NPT
 Sch - BWG
14

15.  Heat Exchanger Data Sheet :
 Design pressure
 Design temperature
 Dimensions / passes
 Tubes ( dimensions, pattern)
 Nozzles & Connections
 TEMA type
15
 Baffles (No. & Type)

16. 16

17.  A – Yield StrengthA – Yield Strength
 B – Tensile StrengthB – Tensile Strength
 C – Rupture pointC – Rupture point
A
B
C
17

18.  Creep Strength
a slow plastic strain increased by time and temperature (time and
temperature dependant) for stressed materials
 Fatigue Strength
The term “fatigue” refers to the situation where a specimen breaks
under a load that it has previously withstood for a length of time
 Toughness
The materials capacity to absorb energy, which, is dependant upon
strength as well as ductility
18

19. ASME code OverviewASME code Overview
ASME
BPV
code
Sec.I Power Boilers
Sec.II Materials
Sec.III Nuclear Fuel Containers
Sec.IV Heating Boilers
Sec. V Non Destructive Examination
Sec. VI Operation of heating boilers
Sec. VII Operation of power boilers
Sec. VIII Pressure vessels
Sec. IX Welding and Brazing
Sec. X Fiber-Reinforced plastic PV
Sec. XI Inspection of nuclear power plant
Sec. XII Transport tanks
19

20. ASME code overviewASME code overview
 Sec. II: Materials
 Part A : Ferrous material specifications
 Part B : Non-Ferrous material specifications
 Part C : Specifications of welding rods, electrodes and filler metals
 Part D : Properties
 Sec. VIII: Rules of construction of pressure vessels
 Division 1 : 3 Subsections + mandatory Annex + non mandatory Annex
 Division 2: Alternative rules
 Division 3 : Alternative rules of high pressure
20

21. 21
ASME code overviewASME code overview

22. TEMA code overviewTEMA code overview
 TEMA classes:
 Class R: Generally severe requirements for petroleum
and related processing applications
 Class C: Generally moderate requirements of commercial
and general processing applications
 Class B: Chemical Process service
 TEMA subsections
 10 subsection
22

23. Sample CalculationsSample Calculations
 Shell thickness calculations under Internal Pressure:
 t : Min. Required Shell Thickness
 P : Design Pressure of Shell Side
 S: Max. Allowable Stress of Shell Material
 R: Shell Inside Radius (corroded conditions)
 E : Joint Efficiency
 CA: Corrosion Allowance
 UT: Under Tolerance (if applicable)
PR .
SE – 0.6 P
+ CAt = + UT
23

24. Sample CalculationsSample Calculations
 Channel thickness calculations under Internal Pressure:
 t : Min. Required Channel Thickness
 P : Design Pressure of Tube Side
 S: Max. Allowable Stress of Channel Material
 R: Channel Inside Radius (corroded conditions)
 E : Joint Efficiency
 CA: Corrosion Allowance
 UT: Under Tolerance (if applicable)
PR .
SE – 0.6 P
+ CAt = + UT
24

25. Sample CalculationsSample Calculations
 Body Flanges:
25

26. Sample CalculationsSample Calculations
 Body Flanges:
 Trial and error calculations
 Gasket seating conditions
 No. of bolts and size
 Bolt circle diameter
 Inside and outside diameters
 Check min. and max. bolt spacing
 Detailed analysis of the flange
 Forces calculations
 Moment calculations
 Stresses calculations
26
 Operating conditions

27. Sample CalculationsSample Calculations
 Precautions in body flanges design and installations:
 Pairs of flanges
 Bolt holes shall straddle center line
 Corrosion Allowance
 Bolts shall be multiple of 4
 Bolting shall be allowed to be removed from either side
27
 Calculated thickness not include the RF
 Cladding

28. 28
Sample CalculationsSample Calculations
 Nozzles and standard flanges:
 Flange Rating (ASME B16.5)
 Nozzle neck thickness calculations
 Area replacement calculations
Sample
 Impingement protection

29. 29
Sample CalculationsSample Calculations
Tubesheet:
• Tubesheet is the principal barrier between shell side and tube side
• Tubes shall be uniformly distributed
• Tubesheet thickness shall be designed for both sides
• Tubesheet shall be designed for bending stresses and shear stresses
• Corrosion allowance
• Made from around flat piece of metal with holes drilled for the tubes

30. 30
Sample CalculationsSample Calculations
Tubesheet:
• Tubesheet thickness for bending
T: Effective tubesheet thickness
S: Allowable stress
P: Design pressure corrected for vacuum if applicable at the other side
η: Ligament efficiency
For Square
pattern
For Triangular
pattern
G: Gasket effective diameter
F: Factor

31. 31
Sample CalculationsSample Calculations
Tubesheet:
• Tubesheet thickness for Shear:
T: Effective tubesheet thickness
DL: Effective diameter of the tube center parameter DL=4A/C
C: Perimeter of the tube layout
A: Total area enclosed by the Perimeter C
P: Design pressure
S: Allowable stress
do: Outside tube diameter

32. 32
Tube-to-TubesheetTube-to-Tubesheet
jointjoint
Expanded
Seal welded
Strength welded

33. 33
Hydrostatic TestHydrostatic Test
 Test pressure : 1.3 X MAWP
 Test Procedure
 Gasket change

34. 34
Sample drawingSample drawing
Construction drawing is the design output
Sample drawing 1 Sample drawing 2

35. 35
Baher EL Shaikh
baherfm@yahoo.com