More Related Content
What's hot
What's hot (20)
Similar to 1. Course highlights.pdf
Similar to 1. Course highlights.pdf (20)
Recently uploaded
Recently uploaded (20)
1. Course highlights.pdf
- 2. INTRODUCTION TYPES OF HEAT EXCHANGERS Co-current Counter current In counter current flow, the hot and cold fluids flow in the opposite direction In co-current flow, both the hot and cold fluids flow in the same direction Tci : Cold fluid inlet temperature Thi : Hot fluid inlet temperature Tco : Cold fluid outlet temperature Tho : Hot fluid outlet temperature Tci Thi Tco Tho Tci : Cold fluid inlet temperature Thi : Hot fluid inlet temperature Tco : Cold fluid outlet temperature Tho : Hot fluid outlet temperature Thi Tho Tco Tci
- 3. VARIOUS TYPES TYPES OF HEAT EXCHANGERS Shell and tube 1 Air cooled 2 Plate and frame 3 Spiral plate 4 Plate and fin 5 Spiral tube 6 Double pipe 7 Bayonet 8 Jacketed vessels 9 Fired heaters 0 1
- 4. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types Fluids characteristics (thermal properties, viscosities, fouling...) 1 Process conditions (t’puts, temperatures...) 2 Space required for the heat exchanger 3 Type and size of foundation 4 Maintenance costs 5 CONSIDERATIONS IN TEMA TYPE SELECTION
- 5. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types BEM Fixed tube sheet heat exchanger
- 6. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types U tube heat exchanger CFU
- 7. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types Outside packed stuffing box heat exchanger AEP
- 8. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types Outside packed lantern ring heat exchanger AJW
- 9. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types Internal floating head heat exchanger AES
- 10. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types Kettle type floating head reboiler AKT
- 11. SHELL AND TUBE TYPES OF HEAT EXCHANGERS TEMA types AKT AES AJW AJW CFU BEM
- 12. SHELL AND TUBE TYPES OF HEAT EXCHANGERS Floating tube sheet Straight tubes secured at both ends One tube sheet is free to move Tube bundle may be removed Covers, gaskets… are accessible for Mtce
- 13. SHELL AND TUBE TYPES OF HEAT EXCHANGERS Floating tube sheet Outside packed stuffing box 1 Outside packed lantern ring 2 Internal floating head 3 AEP AJW AES
- 14. AIR COOLERS TYPES OF HEAT EXCHANGERS Overview Forced draft Induced draft
- 15. AIR COOLERS TYPES OF HEAT EXCHANGERS Forced draft / Induced draft Fan Tube bundle Hot process fluid Cold ambient air Cold ambient air Forced draft Induced draft Fan Tube bundle Hot process fluid AIR IS PUSHED AIR IS PULLED Cold ambient air Cold ambient air
- 16. AIR COOLERS TYPES OF HEAT EXCHANGERS AIR IS PUSHED AIR IS PULLED Less horse power requirement More flexibility for mounting the unit More uniform air distribution Less exhaust air recirculation Less heat transfer area requirement Forced draft / Induced draft
- 17. PLATE AND FRAME TYPES OF HEAT EXCHANGERS Overview Embossed plates Top carrying bar Bottom guide bar Frame plate (stationary) Pressure plate Gasket HOT IN COLD IN COLD OUT Corner openings HOT OUT
- 18. PLATE AND FRAME TYPES OF HEAT EXCHANGERS Overview Construction details (single / double pass…) Design basis (Plates, gaskets…) Heat capacity control Maintenance practices (assembling, disassembling, cleaning, gasket replacement…) More on Plate HX further ahead :
- 19. PLATE AND FIN TYPES OF HEAT EXCHANGERS Overview 13 Al ALUMINUM 26.982 29 Cu COPPER 63.546
- 20. PLATE AND FIN TYPES OF HEAT EXCHANGERS Overview 13 Al ALUMINUM 26.982 29 Cu COPPER 63.546
- 21. DOUBLE PIPE TYPES OF HEAT EXCHANGERS Overview True counter current flow Simplicity of construction Low cost Well adapted to high P / T applications Primarily used for low flow rates Jacketed pipe HX
- 22. DOUBLE PIPE TYPES OF HEAT EXCHANGERS Overview Jacketed pipe HX
- 23. DOUBLE PIPE TYPES OF HEAT EXCHANGERS Overview Jacketed pipe HX
- 24. JACKETED VESSELS TYPES OF HEAT EXCHANGERS Overview Half-pipe coil jackets 2 Conventional jackets 1 Zone 2 : Cooling water in ~30°C Zone 1 : Cooling water in ~10°C Steam out (zone 1) Steam out (zone 2) Half pipes Vessel ZONE 2 ZONE 1 Half pipes Vessel
- 25. TUBE CONSTRUCTION Introduction SHELLAND TUBE Tube Seamless Welded
- 26. TUBE CONSTRUCTION Introduction SHELLAND TUBE Tube Seamless Welded
- 27. TUBE CONSTRUCTION Introduction SHELLAND TUBE Tube Thin tubes Thick tubes Used when the tube material is expensive Used when the pressure requires greater strength Used with very corrosive fluids
- 28. TUBE CONSTRUCTION Introduction SHELLAND TUBE Finned Fluted
- 29. Type A Channel and removable cover Type B Bonnet (integral cover) Type C Channel integral with tubesheet Type D Special high pressure closure Type N Channel integral with tubesheet SHELLAND TUBE Stationary head
- 30. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Encompass a maximum heat transfer surface Allow for cleanability inside and outside the tubes Unit area : It is the cross sectional area within the tube layout which encloses one tube within the framework of the spacing pattern
- 31. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Flow perpendicular to 60° angle of unit area Flow perpendicular to 120° angle of unit area Square pitch 2 Diagonal square pitch 3 Pitch OD Tube #1 Tube #2
- 32. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Flow perpendicular to 60° angle of unit area Equilateral triangular pitch 1 Square pitch 2 Diagonal square pitch 3 Suitable when not necessary to clean the tubes outside Does not provide access to the tubes The tubes can only be cleaned chemically
- 33. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Flow perpendicular to 60° angle of unit area Equilateral triangular pitch 1 Square pitch 2 Diagonal square pitch 3
- 34. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Flow perpendicular to 120° angle of unit area Square pitch 2 Diagonal square pitch 3 Equilateral triangular pitch 1
- 35. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Diagonal square pitch 3 Square pitch 2 Mechanical cleaning of the tubes outside is possible
- 36. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Diagonal square pitch 3 Square pitch 2 Mechanical cleaning of the tubes outside is possible
- 37. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Square pitch 2 Diagonal square pitch 3
- 38. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Square pitch 2 Diagonal square pitch 3
- 39. TUBE CONSTRUCTION Tube layout SHELLAND TUBE Equilateral triangular pitch 1 Flow perpendicular to 60° angle of unit area Flow perpendicular to 120° angle of unit area Square pitch 2 Diagonal square pitch 3 Pitch OD Tube #1 Tube #2
- 40. TUBE CONSTRUCTION Tube sheet SHELLAND TUBE Tubes Tube sheet Holes in the tube sheet Expanded into grooves cut into the tube sheet Welded to the tube sheet
- 41. TUBE CONSTRUCTION Tube sheet SHELLAND TUBE Tubes Tube sheet Holes in the tube sheet Example of a tube sheet Fixed Floating Single Double
- 42. TUBE CONSTRUCTION Tube sheet Single tube sheet SHELLAND TUBE
- 43. TUBE CONSTRUCTION Tube sheet SHELLAND TUBE Double tube sheet
- 44. TUBE CONSTRUCTION Tube sheet SHELLAND TUBE Double tube sheet
- 45. SHELLAND TUBE SHELL CONSTRUCTION Type “E” One pass shell COOLERS / CONDENSERS HEATERS / EVAPORATORS INLET (COLD) OUTLET (HOT) OUTLET (COLD) INLET (HOT)
- 46. SHELLAND TUBE SHELL CONSTRUCTION Type “F” COOLERS / CONDENSERS HEATERS / EVAPORATORS INLET (COLD) OUTLET (HOT) OUTLET (COLD) INLET (HOT) Two pass shell
- 47. SHELLAND TUBE SHELL CONSTRUCTION Type “G” COOLERS / CONDENSERS HEATERS / EVAPORATORS INLET (COLD) OUTLET (HOT) OUTLET (COLD) INLET (HOT) Split flow shell
- 48. SHELLAND TUBE SHELL CONSTRUCTION Type “H” Double split flow LONGITUDINAL BAFFLES (solid or perforated)
- 49. SHELLAND TUBE SHELL CONSTRUCTION Type “H” Double split flow HEATERS / EVAPORATORS INLET (COLD) OUTLET (HOT)
- 50. SHELLAND TUBE SHELL CONSTRUCTION Type “H” Double split flow COOLERS / CONDENSERS INLET (HOT) OUTLET (COLD)
- 51. SHELLAND TUBE SHELL CONSTRUCTION Type “J” Divided flow Suitable for low pressure drop requirements
- 52. SHELLAND TUBE SHELL CONSTRUCTION Type “J” Divided flow HEATERS / EVAPORATORS INLET (COLD) OUTLET (HOT)
- 53. SHELLAND TUBE SHELL CONSTRUCTION Type “J” Divided flow COOLERS / CONDENSERS INLET (HOT) OUTLET (COLD)
- 54. SHELLAND TUBE SHELL CONSTRUCTION Type “K” Kettle reboiler DOME SPACE WEIR (welded to the shell)
- 55. SHELLAND TUBE SHELL CONSTRUCTION Type “K” Kettle reboiler VAPOR LIQUID SHELL INLET
- 56. SHELLAND TUBE SHELL CONSTRUCTION Type “K” Kettle reboiler VAPOR LIQUID SHELL INLET TUBE INLET TUBE OUTLET
- 57. SHELLAND TUBE SHELL CONSTRUCTION Type “X” Cross flow shell Suitable for low pressure drop requirements
- 58. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Introduction Tube sheet Baffles Tube Tie rods
- 59. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Introduction Baffles Provide support to the tubes Prevent damage from mechanical vibrations Direct the flow through the shell side
- 60. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Introduction Baffles Segmental baffles Tie rods and spacers Impingement baffles Vapor distribution Tube bundle bypassing Longitudinal baffles
- 61. Single segmental baffle arrangement SHELLAND TUBE BAFFLE AND TUBE BUNDLES Segmental baffles Shell Shell Baffle pitch Baffle pitch Baffle Baffle Minimum baffle spacing is 1/5th of the shell diameter and not less than 2” (50.8 mm) Maximum unsupported tube span : 74 d0.75 d : tube OD (in) 29 Cu COPPER 63.546 13 Al ALUMINUM 26.982 (1-0.12) x 74 d0.75
- 62. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Segmental baffles Shell Baffle pitch Baffle Baffle Cross flow velocity Baffle pitch Heat transfer coeff. Pressure drop
- 63. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Segmental baffles No tubes in window 4 Single 1 Triple segmental 3 Double 2 Window-cut baffle
- 64. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tie rods and spacers Tube bundle assembly Tube Tie rod Spacer Baffle Screws into the stationary tube sheet on one side Secures the last baffle with a nut on the other end Tie rods Hold the baffles in place Spacers Locate the the baffles Reduce bypassing of the tubes
- 65. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Impingement baffles at high velocity condensing a two phase fluid When the shell side fluid is : The tube bundle should be protected against impingement
- 66. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Impingement baffles BAFFLE Cross sectional view Shell inlet nozzle
- 67. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Vapor distribution COOLERS / CONDENSERS More inlet nozzles Larger inlet nozzles SHELL OUTLET NOZZLE (Liquid) LARGE INLET NOZZLE (Vapor) 1 3 2 Inlet nozzle Inlet nozzle Inlet nozzle Vapor distribution system
- 68. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tube bundle bypassing
- 69. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tube bundle bypassing Shell side heat transfer rates Tube bundle bypassing Shell Outer tube limit Outer tube limit Clearance between outer tube limit and shell Clearance
- 70. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tube bundle bypassing Shell side heat transfer rates Tube bundle bypassing Shell Clearance between longitudinal baffle and shell Clearance Longitudinal baffle Cross sectional view
- 71. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tube bundle bypassing Shell side heat transfer rates Tube bundle bypassing Clearance between longitudinal baffle and shell Clearance Cross sectional view
- 72. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Tube bundle bypassing Reducing tube bundle bypassing Sealing strip Sealing strip Bypass restricted with sealing strips Bypass without sealing strips Sealing strips Extend from baffle to baffle Inserted in slots cut into the baffle
- 73. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Longitudinal baffles Longitudinal baffle Longitudinal baffles can be insulated to improve thermal efficiency !!! FIXED TUBE SHEET Longitudinal baffle Achieve multi-passes in HX shells
- 74. SHELLAND TUBE BAFFLE AND TUBE BUNDLES Longitudinal baffles Longitudinal baffle Longitudinal baffles can be insulated to improve thermal efficiency !!! Longitudinal baffle welded to the shell Weld Bypassing restricted Bypassing restricted Cross sectional view FIXED TUBE SHEET
- 75. MORE ON TUBE PATTERN DESIGN OF HEAT EXCHANGERS SQUARE ROTATED SQUARE TRIANGULAR Good heat transfer More tubes can fit in the shell To be used for severe fouling on the shell side
- 76. HOW TO CONNECT DESIGN OF HEAT EXCHANGERS MULTIPLE HX IN SERIES T1 : Shell-side inlet temperature (°C) T2 : Shell-side outlet temperature (°C) t1 : Tube-side inlet temperature (°C) t2 : Tube-side outlet temperature (°C) T1 T2 t1 t2 T2 t1 T1 t2 T2 t1 T1 t2 2 exchangers 1 exchanger 3 exchangers
- 77. DESIGN OF HEAT EXCHANGERS INFLUENCE OF BYPASS STREAMS ON LMTD Longitudinal baffle Bypass through clearance Bypass through clearance Shell Therefore only a part of the shell-side product stream is heated or cooled This part is heated or cooled more because the flow is smaller !!! Tube bundle bypassing LMTD TUBE BUNDLE BYPASSING
- 78. DESIGN OF HEAT EXCHANGERS MORE ON THE TUBE SIDE HEAT TRANSFER COEFF. The flow velocity and the heat transfer coefficient can be increased through a multipass arrangement Tube side flow velocity Tube side flow cross section Keep in mind, in a multipass arrangement : Tube side heat transfer coeff. Increase of the pressure loss Reduction of the effective temperature difference There is no ideal countercurrent flow
- 79. DESIGN OF HEAT EXCHANGERS MORE ON THE SHELL SIDE HEAT TRANSFER COEFF. SHELL SIDE PRODUCT STREAMS ACCORDING TO TINKER T. Tinker, Shell side characteristics of shell and tube HX, Trans. ASME 80 Stream A : Leakage stream through the gap between the tubes and the baffle holes Shell Shell Baffle Baffle holes
- 80. DESIGN OF HEAT EXCHANGERS MORE ON THE SHELL SIDE HEAT TRANSFER COEFF. SHELL SIDE PRODUCT STREAMS ACCORDING TO TINKER T. Tinker, Shell side characteristics of shell and tube HX, Trans. ASME 80 Stream A : Leakage stream through the gap between the tubes and the baffle holes Stream B : Cross stream through the bundle Shell Shell Baffle Baffle holes
- 81. DESIGN OF HEAT EXCHANGERS MORE ON THE SHELL SIDE HEAT TRANSFER COEFF. SHELL SIDE PRODUCT STREAMS ACCORDING TO TINKER T. Tinker, Shell side characteristics of shell and tube HX, Trans. ASME 80 Stream A : Leakage stream through the gap between the tubes and the baffle holes Stream B : Cross stream through the bundle Stream C : Bypass stream through the annular gap between the bundle and the shell Shell Shell Baffle Baffle holes
- 82. DESIGN OF HEAT EXCHANGERS MORE ON THE SHELL SIDE HEAT TRANSFER COEFF. SHELL SIDE PRODUCT STREAMS ACCORDING TO TINKER T. Tinker, Shell side characteristics of shell and tube HX, Trans. ASME 80 Stream A : Leakage stream through the gap between the tubes and the baffle holes Stream B : Cross stream through the bundle Stream C : Bypass stream through the annular gap between the bundle and the shell Stream D : Bypass stream between the baffle and the shell Shell Shell Baffle Baffle holes
- 83. DESIGN OF HEAT EXCHANGERS IMPORTANT NOTES TO REMEMBER !!! To reduce the pressure loss on the shell side : Alter the baffle spacing and baffle arrangement Use larger pitch or quadratic pitch Use shorter tube lengths Use larger nozzle diameter Install a pure cross stream heat exchanger (TEMA “J” or “X”)
- 84. DESIGN OF HEAT EXCHANGERS IMPORTANT NOTES TO REMEMBER !!! What is important for a heat exchanger ? High flow velocity Low bypass and leakage streams Multiple passes on the tube side Small clearance between tube and baffle plate holes Small clearance between baffle and shell Longitudinal plates or sealing strips
- 85. DESIGN OF HEAT EXCHANGERS Shell outer diameter (Do) Shell inner diameter (Di) Sealing strips (limit bypass stream) Tie rods (support tube bundle) Shell outer limit diameter (DH) (envelope of tube pattern) ROTATED SQUARE Pitch (T) Tube outer diameter (do) Tube inner diameter (di)
- 86. DESIGN OF HEAT EXCHANGERS Baffle (front one, another baffle oriented upside down is behind it) (alternating baffle arrengement)
- 87. DESIGN OF HEAT EXCHANGERS “Rear” baffle Baffle (front one, another baffle oriented upside down is behind it) (alternating baffle arrengement) Segmental height (H) (height of the baffle cut)
- 88. DESIGN OF HEAT EXCHANGERS Total number of tubes (n)
- 89. DESIGN OF HEAT EXCHANGERS Number of tubes in cross stream on the center line (nacr)
- 90. DESIGN OF HEAT EXCHANGERS Number of vertical tube rows (ntv)
- 91. DESIGN OF HEAT EXCHANGERS Baffle Segmental height (H) (height of the baffle cut) #1 Baffle window #1 Number of tubes in the baffle window (nw)
- 92. DESIGN OF HEAT EXCHANGERS Number of tubes in the baffle window (nw) Baffle Segmental height (H) (height of the baffle cut) #2 Baffle window #2
- 93. DESIGN OF HEAT EXCHANGERS Segmental height (H) (height of the baffle cut) Baffle window #1 Baffle window #2
- 94. DESIGN OF HEAT EXCHANGERS Segmental height (H) (height of the baffle cut) Baffle window #1 Baffle window #2 Number of vertical tube rows between baffle windows (ncross)
- 95. FOULING TENDENCIES GUIDELINES FOR ALLOCATION OF STREAMS Fouling on tubes HX thermal performance Tubes pressure drop Minimize fouling Facilitate cleaning
- 96. FOULING TENDENCIES GUIDELINES FOR ALLOCATION OF STREAMS Fixed tube sheet HX BEM Clean fluid Dirty fluid
- 97. CORROSION GUIDELINES FOR ALLOCATION OF STREAMS Can cause severe damage to the heat exchanger ! The shell need not be made of corrosion resistant material
- 98. CORROSION GUIDELINES FOR ALLOCATION OF STREAMS The shell need not be made of corrosion resistant material Made of corrosion resistant alloys
- 99. CORROSION GUIDELINES FOR ALLOCATION OF STREAMS The shell need not be made of corrosion resistant material Made of corrosion resistant alloys If the corrosion cannot be effectively prevented but slowed by choice of material, a design must be chosen in which corrodible components can be easily replaced !!!
- 100. CORROSION GUIDELINES FOR ALLOCATION OF STREAMS The shell need not be made of corrosion resistant material Made of corrosion resistant alloys COOLING WATER
- 101. CRITICALITY OF FLUIDS GUIDELINES FOR ALLOCATION OF STREAMS Should be positively contained to prevent leaks !!! AES AEP AJW AKT
- 102. PHYSICAL STATE GUIDELINES FOR ALLOCATION OF STREAMS OF THE FLUIDS The shell side tends to be preferred for services with phase changes ! Kettle type floating head reboiler AKT Larger cross section Lower pressure drops
- 103. OPERATING PRESSURE GUIDELINES FOR ALLOCATION OF STREAMS AND TEMPERATURE Temperature / Pressure Metal thickness Cost of HX construction High Temp. / P fluid The tubes being smaller in Φ than the shell, withstand higher pressures
- 104. ALLOWABLE GUIDELINES FOR ALLOCATION OF STREAMS PRESSURE DROP Fluids with low allowable pressure drop should be placed on the tube side Low allowable dP Streamlined flow Lower turbulence Tubes facilitate :
- 105. To obtain an economic design high heat transfer coefficients are required Heat transfer coefficients Flow turbulence • Highly viscous fluids • Low flowrates Re < 200 Use a high number of tube passes to velocity GUIDELINES FOR ALLOCATION OF STREAMS HIGH VISCOSITY LOW FLOWRATES
- 106. FLUID VELOCITY GUIDELINES FOR ALLOCATION OF STREAMS High velocity fluid Tube side Velocity Heat transfer coefficients Fouling High velocity fluids
- 107. LOW HEAT GUIDELINES FOR ALLOCATION OF STREAMS TRANSFER COEFF. Low heat transfer coeff. fluids Shell side Tube Tie rod Spacer Baffle
- 108. THERMAL EXPANSION GUIDELINES FOR ALLOCATION OF STREAMS Temperature change > 150 °C High temperature change fluid The shell better able to handle large temperature changes !
- 109. FLUID ALLOCATION : WHAT YOU SHOULD REMEMBER GUIDELINES FOR ALLOCATION OF STREAMS side Tube Fouling, erosive or corrosive fluids Toxic, lethal or valuable fluids Fluids with less allowable pressure drop Less viscous fluids Higher pressure / Higher temperature fluids Fluids with higher volumetric flowrate Cooling water NOTE : While deciding the fluid allocation, many trade-offs are made in heat transfer coefficients, pressure drops… None of the suggestions discussed in this section are definitive ! Use them only as a starting point.
- 110. GUIDELINES FOR ALLOCATION OF STREAMS side Viscous fluids Fluids with lower volumetric flowrate High temperature change fluids Shell NOTE : While deciding the fluid allocation, many trade-offs are made in heat transfer coefficients, pressure drops… None of the suggestions discussed in this section are definitive ! Use them only as a starting point. FLUID ALLOCATION : WHAT YOU SHOULD REMEMBER