1. Heat Exchangers

2. Heat Exchangers
•Heat exchangers are one of the most common pieces of
equipment found in all plants.
•Heat Exchangers are components that allow the
transfer of heat from one fluid (liquid or gas) to another
fluid.
•In a heat exchanger there is no direct contact between
the two fluids. The heat is transferred from the hot fluid
to the metal isolating the two fluids and then to the
cooler fluid.

3. Types of Heat Exchangers

4. Double-Pipe Exchanger

5. Double Pipe
Simplest type has one tube inside another - inner
tube may have longitudinal fins on the outside
However, most have a
number of tubes in the outer
tube - can have very many tubes
thus becoming a shell-and-tube

6. Shell-and-Tube Heat Exchanger

7.  Shell-and-Tube Heat Exchangers are the most
important type of HE.
 It is used in almost every type of industry.
 This type of heat exchanger consists of a set of
tubes in a container called a shell.
 The fluid flowing inside the tubes is called the
tube side fluid and the fluid flowing on the outside
of the tubes is the shell side fluid.

8. Main Components of Shell-and-Tube
Heat Exchangers

9. Some common heat-exchanger
terms
 Tube side: Inside the tubes.
 Shell side: Outside the tubes, between the
tubes and the shell.
 Tube sheet A thick plate provided with holes
(one per tube) in which the tubes are fixed.
 Tube bundle Consists of tubes, tube sheet and
baffle plates
 Shell A cylinder of plate in which the tube bundle
is placed

11. TEMA Heat
Exchangers

12. Shell and Tube Heat Exchangers
Construction
 Fixed Tube-sheet type
 U-tube type
 Floating Head type

13. Front head type
 A-type
 B-type
B
Channel and removable cover Bonnet (integral cover)
A

14. Shell type
 E-type
 F shell
E F
One-pass shell Two-pass
shell
Longitudinal baffle

15. More shell types
 G and H shells normally only used for horizontal thermosyphon
reboilers
 J and X shells if allowable pressure drop can not be achieved in an E
shell
J
HG
X
Split flow Double split flow
Divided flow Cross flow
Longitudinal
baffles

16. Low-finned Tubes
 Flat end to go into tube sheet and
intermediate flat portions for baffle
locations
 Available in variety of metals including
stainless steel, titanium and inconels

17. Plate and frame
 Plates hung vertically and
clamped in a press or frame.
 Gaskets direct the streams
between alternate plates and
prevent external leakage
 Plates made of stainless steel or
higher quality material
 Plates corrugated to give points
of support and increase heat
transfer

18. Plate Heat Exchanger

19. Chevron Washboard
Plate types
Corrugations on plate
improve heat transfer
give rigidity
Many points of
contact and a
tortuous flow path

20. General view of
plate exchanger
“Plate exchanger”
normally refers
to a gasketed
plate- and-frame
exchanger

21. Flow Arrangement within a
PHE
Alternate plates (often same plate types inverted)
Gaskets
arranged for
each stream to
flow between
alternate plates

22. Air-Cooled or Fin-Fan
Exchanger

23. Air-cooled exchanger
 Air blown across finned tubes (forced
draught type)
 Can suck air across (induced draught)
Finned tubes

24. ACHE bundle

25. Spiral Heat Exchanger

26. Spiral Heat Exchangers
 Spiral heat exchangers can be used in most applications in the
chemical process industry
 In many difficult applications where fouling and plugging are
problems, a standard shell and tube design may not be
effective
 While a spiral heat exchanger often has a higher initial cost, it
may provide a lower life cycle cost due to lower fouling rates
and ease of maintenance

27.  A spiral heat exchanger is composed
of two long, flat plates wrapped
around a mandrel or center tube,
creating two concentric spiral
channels
 In a spiral heat exchanger, the hot
fluid flows into the center of the unit
and spirals outward toward the outer
plates while at the same time, the cold
fluid enters the periphery and spiral
inward, exiting at the center