Basics of Shell and Tube Heat Exchangers: A brief presentation [With PDF]

What is a Heat Exchanger?

A Heat exchanger is a device to transfer heat from one fluid (Liquid/Gas) to another. There are various types of heat exchangers used in process piping. Shell and tube heat exchanger is the most widely used heat exchanger. Fig 1 shows the typical working principle of a shell and tube heat exchanger.

Working principle of Typical Shell and Tube Heat Exchanger
Fig. 1: Working principle of Typical Shell and Tube Heat Exchanger

Basic Components of Shell and Tube Heat Exchanger

Typically a Shell and Tube Heat Exchanger consists of two-compartment / section one is shell side and other is channel/tube side

  • Shell side section consists of the following components: Shell, Cover, Body Flange, Nozzles, Saddle support.
  • Channel / Tube side section consists of the following components: Channel, Cover, Body Flange, Nozzles, Tube Sheet and Tubes  (Tube Bundle)
Components of a Shell and Tube Heat Exchanger
Fig. 2: Components of a Shell and Tube Heat Exchanger

Tube Bundle

Tube Bundle (Fig. 3) consists of the following components

  • Tube sheet
  • Tubes
  • Baffles
  • Tie rods and Spacers
  • Sliding strips
Typical tube bundle of a shell and tube heat exchanger
Fig. 3: Typical tube bundle of a shell and tube heat exchanger

Tube Pattern (Fig. 4)

Typical tube patterns
Fig. 4: Typical tube patterns

Tube Pitch

The tube shall be placed with a min. c/c distance of 1.25 times the tube outside diameter of the tube. When mechanical cleaning of the tube is specified then min. A cleaning lane of 6.4 mm shall be provided.

Type of Shell and Tube Heat Exchanger

TEMA Exchanger Type

  • R –  Refinery and Petrochemical Application
  • C –   General Process Application
  • B – Chemical Process Application

TEMA Heat Exchanger applicable Criteria

  • Inside diameter 2500 mm
  • Product of nominal diameter (mm) and design pressure (kPa) of   5 x 106
  • design pressure of 3000 psig

Fixed Tube Sheet Heat Exchanger (Fig. 5)

Example of a typical fixed tube heat exchanger
Fig. 5: Example of a typical fixed tube heat exchanger

Floating Head Heat Exchanger Removable Bundle (Fig. 6)

Example of a typical Floating Head Removable bundle heat exchanger
Fig. 6:Example of a typical Floating Head Removable bundle heat exchanger

Stationary Tube sheet with removable tube bundle (Fig. 7)

Example of a typical stationary tube sheet type heat exchanger
Fig. 7: Example of a typical stationary tube sheet type heat exchanger

Stack Types of Configuration

In this, two or three heat exchangers placed one above other. This is termed as 1 shell in parallel and 2 or 3 Shells in series. Refer Fig. 8.

Figure showing stack arrangement of heat exchangers
Fig. 8: Figure showing stack arrangement of heat exchangers

Design codes used for Heat exchangers

  • API 660 / ISO 16812 ( Shell and Tube heat exchangers for general refinery service )
  • ASME SECT.VIII Div.1 (UHX) or Div.2, PD 5500, EN 13445, AD 2000 Merkblatt.
  • TEMA -Tubular Exchanger Manufacturers Association
  • Shell DEP 31.22.20.31 and DEP 31.21.01.30

Software for used Thermal Design

  • HTRI – Heat Transfer Research Institute
  • HTFS – Heat Transfer Research and fluid flow service

Design of Shell and Tube Heat exchangers

  • MIN. SHELL THK.(Fig. 9) as per TEMA for class – R\
Minimum Shell thickness of shell and tube heat exchanger
Fig. 9: Minimum Shell thickness of shell and tube heat exchanger
  • Baffle clearance, Baffle spacing and thickness as per TEMA table RCB -4.3
  • Tie rod size and nos. as per TEMA table R- 4.71  for class – R
  • PERIPHERAL GASKET: The min. width of the peripheral ring gasket for external joints shall be 10 mm for shell sizes up to 584 mm and 12 mm for all larger shell sizes.
  • PASS PARTITION GASKET: The min. width of the gasket web for pass partition of the channel shall not be less than 6.4 mm for shell sizes up to 584 mm and 9.5 mm for all larger shell sizes. Gasket  joint shall be confined type
  • Shell and Head design is done as per selected Pressure vessel Design Code  such as ASME, EN or AD
  • The most widely used design code across the world is ASME Sect. VIII Div.1 & 2
  • Body / Girth Flange Design as per Appendix -2 of ASME Sect. VIII Div.1
  • The tube sheet design is Mandatory as per UHX of ASME Sect. VIII Div.1
  • The tube sheet is designed for the following three cases.
    • Tube side pressure (Pt) acting and Shell side pressure (Ps) is Zero
    • Shell side pressure (Ps) acting and Tube side pressure (Pt) is Zero
    • Shell side pressure (Ps) acting and Tube side pressure (Pt) acting
  • Please consider the effect of Vacuum in above load cases
  • Tube sheet Design formula based on the theory of Flat Plates

Material of Construction most widely used:

  • Carbon steel and Cladding Plates
  • Stainless Steel
  • Duplex Stainless steel
  • Tubes –  Carbon steel, Stainless steel, Duplex stainless steel, Exotic material such as copper, Inconel, Titanium

Application of Heat Exchangers

Shell & Tube Heat Exchangers find their application in the following Industries-

  • Refinery and Petrochemical
  • Fertilizer
  • Oil and Gas
  • Chemical

Few more resources for You..

Shell & Tube Heat Exchanger Piping: A brief Presentation
An article on Plate Heat Exchanger with Steam
A typical Check List for Reviewing of Shell & Tube Heat Exchanger Drawings
A brief presentation on Air Cooled Heat Exchangers
Basic Considerations for Equipment and Piping Layout of Air Cooled Heat Exchanger Piping
Reboiler Exchanger and System Type Selection

Anup Kumar Dey

I am a Mechanical Engineer turned into a Piping Engineer. Currently, I work in a reputed MNC as a Senior Piping Stress Engineer. I am very much passionate about blogging and always tried to do unique things. This website is my first venture into the world of blogging with the aim of connecting with other piping engineers around the world.

4 thoughts on “Basics of Shell and Tube Heat Exchangers: A brief presentation [With PDF]

  1. What I like the most about the shell & tube design compare to other type like plate and frame or helicoil is that despite the fact they are built to last for a longer life is:
    1- The tube bundle is easy to replace because you have just one or 2 gaskets to replace
    2- They are easy to repair a tube temporary by plugging it for a fast restart of the process while waiting for the next shut down
    3- If you need to clean the tubes, you can easily see from your eyes if the tubes are clean enough.
    4- For high scale application their is the possibilty to add an automatic brush in each tube to avoid any scale or plug tube.

    In steam application I suggest to use a vertical shell & tube design to flood the heat exchanger.

  2. Congratulations
    Great presentation with very easy explanation to understand the fundamentals of heat exchanger
    Thank you

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