Hey! This is the best presentation about Heat exchanger device of shell and tubes type and there is also mentioned their defects and overcome method...
2. TRANSFER OF THERMAL
ENERGY BETWEE
TWO OR MORE FLUIDS
between a solid surface and a
fluid
between solid particulates and a
25-11-2015Transport Phenomenon (CH 306)
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Heat exchanger
4. Based on transfer process
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Indirect Contact – Shell & Tube Heat Exchangers
Direct Contact – Cooling Towers
Gas-Liquid exchangers
Liquid-Liquid exchangers
Gas-Gas heat exchangers
Based on phase of fluids
5. Based on construction
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Tubular
Double pipe heat exchanger
Shell and tube heat exchangers
Spiral heat exchangers
Plate-type
Plate and frame heat exchangers
Spiral plate heat exchangers
Extended Surface
Plate-fin exchanger
Tube-fin exchanger
10. Shell and Tube Heat exchanger
A system with Shell & Tubes used for heat
exchange.
A shell (a large pressure vessel) with a
bundle of tubes inside it.
11. Working
One fluid runs through the tubes,
and another fluid flows over the
tubes (through the shell) to
transfer heat between the two
fluids.
The set of tubes is called a tube
bundle.
See the Animation………
13. Types of shell & tube H.E
• Among the several types : given are most readily
used.
14.
15.
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Advantages
Less expensive as compared to Plate
type coolers
Can be used in systems with higher
operating temperatures and
pressures
Pressure drop across a tube cooler
is less
Tube leaks are easily located and
plugged since pressure test is
comparatively easy
Disadvantages
Heat transfer efficiency is less
compared to plate type cooler
Cleaning and maintenance is
difficult since a tube cooler
requires enough clearance at one
end to remove the tube nest
Requires more space in
comparison to plate coolers
17. Bafels
Device used to restrain the flow of a fluid or to
prevent the spreading of fluid in a particular
direction.
Flow-directing panel in some vessels such as
shell and tube heat exchangers, chemical
reactors, or static mixers.
18. Use of Baffles In Shell And Tube Heat
Exchangers
Why are baffles used?
To support the tube
To direct the fluid stream across the tube
To improve the rate of heat transfer Shell
Tubes
Baffle
21. Fouling
• Fouling occurs when any type of particles both
organic or inorganic plug or plate out on heat
transfer surfaces creating a resistance to
transfer energy
• There are two types of fouling
– Macro-fouling
– Micro-fouling
22. Macro Vs Micro Fouling
• Macro-fouling
– Sand
– Silt
– Scale
– Rust
– Mineral deposits
Example- CaCO3
• Micro-fouling
– Biological growth
– Algae
– Bacteria
– Mussels
• Micro-fouling is
controlled by water
treatment
23. 2.Corrosion of heat exchangers
Another series problem in heat exchangers is corrosion
Severe corrosion can and does occur in tubing and very
often with common fluids such as water.
To avoid corrosion
►Proper material selection based on full analysis of the
operating fluids, velocities and temperatures is a must.
►Protection of the heat exchanger from corrosion [e.g.
cathodic protection]
►Treatment of the cooling water used and using inhibitors.
24. 3.Heat exchangers vibration
Vibration of the tubes as a result of the flow of the
shell side past them is important phenomena
specially when the H.X size and flow quantities of
flow are increased
Vibration effects
►Vibration has a bad effect on both tubes and shell
►The joints between the tubes and tube sheet can
fail due to vibration causing leakage
►It causes leakage in the joints between shell and
tubes
►Increase the shut down time to repair the H.X
25. How to avoid vibration
Using inlet support baffles
Using double segmental baffles [improve
tube support]
Inlet support
baffles
Double-segmental baffles
