A double pipe heat exchanger, in its simplest form, is just one pipe inside another larger pipe. One fluid flows through the inside pipe and the other flows through the annulus between the two pipes. The wall of the inner pipe is the heat transfer surface. The pipes are usually doubled back multiple times as shown in the diagram at the left, in order to make the overall unit more compact.
Thermal Capability
Since the heating medium is in direct contact with the entire process pipe surface area, jacketed pipe provides maximum heat transfer to the process. Heat transfer to the process is only limited by the process convection coefficient. For these reasons, jacketed piping possesses the maximum thermal capability for bulk temperature maintenance, wall temperature maintenance, and heat exchanger applications (including melt out).
Applications :
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A primary advantage of a double pipe heat exchanger is that it can be operated in a true counterflow pattern, which is the most efficient flow pattern. |
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It will give the highest overall heat transfer coefficient for the double pipe heat exchanger design. |
Advantages :
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Double pipe heat exchangers can handle high pressures and temperatures well. |
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When they are operating in true counterflow, they can operate with a temperature cross. |
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The cold side outlet temperature is higher than the hot side outlet temperature |
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