In a double tube heat exchanger, we have a large tube and a concentric small tube, and all of the heat transfer process takes place inside the large tube. One fluid flows inside the small tube and the other fluid is between the two tubes, so the inner tube acts as a conductive barrier. The outer side or side of the shell includes the flow of fluid through the inner side or side of the pipe.
This type of heat exchanger is known as stud, jacketed tube, jacketed U-tube, and tube-in-tube heat exchanger. They may consist of a tube or a bundle (less than 30) and the diameter of the outer tube must be less than 200 mm. In some cases, the inner tube has longitudinal ribs to increase the rate of heat exchange between the working fluids.
Specifications and Applications
One of the simplest heat exchangers is a two-pipe heat exchanger. Please note. 1 shows this type of circuit, where one pipe or casing is inside another, as shown in the figure. With a simple and clear design, customers have a variety of options to choose from. There are many non-standard heat exchangers on the market to meet the needs of industries and projects in a variety of applications. This type is best used in small volume applications with a heat transfer area of less than 45 square meters.