Heat
exchangers are widely used in various industrial applications for the
purpose of transferring heat from one fluid or gas to another while
preventing the two from intermingling. Heat exchangers are essential in gas
plants for transferring heat during gas processing. In most heat exchangers
there is a solid wall to separate the fluids and prevent them from mixing.
In some other designs, the fluids may come in contact with each other. Fins
or corrugations are sometimes fixed with the wall so that it can increase
the surface area and induce turbulence.
Materials of Construction
Heat exchangers are typically constructed of
- Stainless steel
- Titanium
- Steel
- Bronze
- Copper
- Aluminum
- Cast iron
Flow Arrangements of Heat Exchangers
Classification of heat exchangers is on the basis of their flow
arrangement. There are three types of flow arrangements:
- Parallel-flow Heat Exchangers: The two fluids
enter the heat exchanger from same end, and move parallel to one another
to the other side.
- Counter-flow Heat Exchangers: Here the fluids
enter from opposite sides. This is supposed to be the most efficient as
it can transfer the most heat.
- Cross-flow Heat Exchanger: Here the fluids move in
a perpendicular fashion.
Types of Heat Exchangers
There are also different types of heat exchangers which we are explaining
below:
- Shell and Tube: This is the most common type of heat
exchanger. It has multiple finned tubes, where one type of fluid runs
through the tubes while the other fluid runs over them, thereby causing
it be heated or cooled. Usually composed of stainless steel straight or
u-tubes, they have coil and baffle arrangement which maximizes heat
transfer performance.
- Plate: Here the fluid flows through baffles, leading the
fluids to be separated by plates with a large surface area. It is
considered more efficient than the shell and tube design. The plates
have corrugation patterns that produce turbulent flow which also helps
in creating a self-cleaning effect thereby reducing fouling.
- Regenerative: This heat exchanger takes advantage of the heat
derived from a specific process so as to heat the fluid used in the same
process. It can be made with the shell and tube design or the plate
design
- Intermediate Fluid or Solid: This type of heat exchangers
uses the fluids or solids inside the body to hold heat and move it to
the other side so as to release it. This heat exchanger is mainly used
to cool gases while removing impurities at the same time.
Diagrammatic Representation of Parts of A Heat Exchanger (Shell and
tube)
Applications
Industrial Applications: They are widely used in
- Chemical plants
- Gas plants
- Petroleum refineries
- Petrochemical plants
- Natural gas processing
- Refrigeration
- Pharmaceutical industry
- Power plants
- Air conditioning
- Space heating
|
- Food processing
- Industrial engineer processes
- Pulp and paper industry
- Steel industry
- Aerospace
- Semiconductor
- Automotive
- Water treatment facilities
- Textiles
|
Residential Applications:
- Radiant floor heating
- Pool heaters
- Domestic hot water
- Snow and ice melting
- Central, solar and geothermal heating
Heat
Exchanger
