1. HARSHAD KANGANE.
M.E. Thermal.
Sem- II.

2. Agenda
 What is a compact heat exchanger?
 Types
 Advantages and limitations
 Cost of heat exchangers
 Care to be taken
 Environmental Aspects
 Conclusion
 Reference

3. Basic Definitions
 A heat exchanger is a device built for efficient heat
transfer from one medium to another, whether the
media are separated by a solid wall so that they never
mix, or the media are in direct contact.

4. What is a Compact Heat
Exchanger?
 HT Area density greater than 700 m2/m3 for gas or
greater than 300 m2/m3 when operating in liquid or
two-phase streams.
 Highly efficient
 Reduce volume, weight and cost

5. Types of CHEs
 Plate and frame heat exchangers: (PHE)
 PHE Countercurrent.mp4

6. Plate and Frame Heat Exchanger
 Most common type of PHE
 Consists of plates and gaskets
 Materials: stainless steel, titanium and non-metallic
 Operation limits:
- temperatures from -35°C to 220°C
- pressures up to 25 bar
- flow rate up to 5000 m3/h

7. Brazed Plate Heat Exchanger (PHE)

8. Brazed Plate Heat Exchanger
 Operates at higher pressures than gasketed units
 Materials: stainless steel, copper contained braze
 Operating limits:
- From -195°C to 200°C
- Pressures up to 30 bar
 It is impossible to clean. The only way is by applying
chemicals.

9. Welded Plate Heat Exchanger (PHE)

10. Welded Plate Heat Exchanger
 Plates welded together to increase pressure and
temperature limits
 Materials: stainless steal and nickel based alloys. Can
be made with copper , titanium or graphite
 Operation Limits:
- temperature limits depend on the material
- can tolerate pressures in excess of 60 bar

11. Spiral Heat Exchanger (SHE)
Spiral HX for Liquid-Liquid.mp4

12. Spiral Heat Exchanger (SHE)
 Two long strips of plate wrapped to form concentric
spirals
 Materials: carbon steel, stainless steel and titanium
 Operation limits:
- Temperatures up to 400°C (depends on gasketed
materials)
- Pressures up to 25 bar

13. Plate Fin Heat Exchanger (PFHE)

14. Plate Fin Heat Exchanger (PFHE)
 High area density and handles several streams
 Materials: aluminum, corrosion and heat resistant
alloys, and stainless steel (available in titanium)
 Operation limits:
- Temperature limits depend on the material
- cryogenic temperature up to 100°C (aluminum)
- stainless steel up to 650°C
- Pressures up to 100 bar for aluminum and 90 bar for
stainless steel

15. Printed-circuit heat exchangers
(PCHE)

16. Printed-circuit heat exchangers
(PCHE)
 Flexibility of design and high strength offered by
techniques of construction
 Materials: Stainless steel 316, alloys, nickel and
titanium.
 The etched plates are stacked and diffusion bonded
together to make the core of Hx
 Operating limits:
- temperature ranges from -200°C to 900°C
- pressures up to 600 bar

17. Compact Shell-and-Tube Heat
Exchanger
To increase surface area, this equipment has a large
number of small diameter tubes

18. Advantages
 Improved energy efficiency
- Closer approach temperatures allows greater energy
transfer.
 Smaller volume and weight
 Higher efficiency
 Lower cost
 Multi-stream and multi-pass configurations
 Tighter temperature control
 Power savings
 Improved safety

19. Limitations
 Lack of industrial awareness
Companies remain aware of technology of CHE
 Limited choice
Particularly for high-pressure
 Conservatism in the user industries
Process industries are reluctant to adopt what they
may seen either as new technologies.
 Susceptibility to fouling
Perception that small passages are likely to foul.
 Expensive.
 Blockages can occurs very easily.

20. Cost of compact heat exchangers
 Compact heat exchanger tend to be cheaper especially
when their total installed cost is considered.
 In some cases the materials used to manufacture is
expensive, but when we consider the cost of unit plus
the installation, the cost is less than equivalent shell
and tube.

21. Cost of compact heat exchangers

22. Care to be taken
 Fouling:
- Use of non-fouling fluids wherever possible is of
course recommended, for example clean air or
gases, light carbons and refrigerants.
- In open systems, check the possible application of
self-cleaning strainers, and the installation of systems
to dose with biocides, scale inhibitors, etc., to control
fouling.
- Use self-cleaning filter if possible
- Consider chemical cleaning. If this is undertaken, the
system must be designed to allow the introduction and
complete removal of cleaning fluids.

23. Corrosion:
 In some CHEs, the wall thicknesses are less than in a
shell-and-tube heat exchanger, so corrosion rates and
allowances need to be accessed carefully
 Although CHEs are often made from more corrosion-
resistant materials than the shell-and-tube units, other
corrosion mechanisms such as cracking may
occur, and the compatibility of the material with the
fluids in the CHE should be checked.

24. Environmental Aspects
 Energy conservation and environmental
considerations are the driving forces behind changes
aimed at reducing both chemical and thermal waste.
 More efficient use of energy and raw materials
 Smaller and cheaper plant
 Ability to handle high-pressure reactions

25. Application
 Automobile
 Marine
 Aerospace, Aircraft
 Criogenic systems
 Refrigeration.
Manufacturers in the Market
 Alfa Laval
 Gea Ecoflex
 Sondex
 Swep
 Tranter
 Funke

26. Conclusion
 Compact heat exchangers are available in a wide
variety of configurations to suit most processes heat
transfer requirements.
 The advantages of CHEs, and associated heat transfer
enhancement techniques, extend far beyond energy
efficiency.
 Lower capital cost, reduced plant size, and increased
safety are typical of the benefits arising from the use of
CHEs.
 Compact heat exchangers can replace some normal
size heat exchangers bringing advantages and
performance.

27. References
 ADVANCES IN COMPACT HEAT EXCHANGERS.
(n.d.). Retrieved March 5, 2009, from
http://www.rtedwards.com/books/164/index.html
 http://www.chemkb.com/equipments/heat-
exchangers/printed-circuit-heat-exchanger-pche
 http://www.alfalaval.com
 http://www.wikipedia.com