Tube heat exchanger
Structure: Concentric sleeves composed of different diameters. Several sections of sleeves can be connected with U-shaped tubes according to heat exchange requirements, in order to increase the heat transfer area; cold and hot fluid can be countercurrent or cocurrent.
Advantages: simple structure, convenient processing, high pressure resistance, large heat transfer coefficient, can maintain complete countercurrent to maximize the average logarithmic temperature difference, and can increase or decrease the number of pipe sections for easy application.
Disadvantages: The structure is not compact, the metal consumption is large, there are many joints and it is easy to leak, and the area is large.
Uses: It is widely used in the ultra-high pressure production process. It can be used in places with small flow and small heat transfer area.
Tube and tube heat exchanger
Tube-and-tube heat exchangers, also known as tube and shell heat exchangers, are the most typical bulkhead heat exchangers with a long history and dominate the role.
Advantages: large heat transfer area provided by unit volume equipment, good heat transfer effect, sturdy structure, wide range of structural materials that can be used, large operating flexibility, and large-scale installations.
Structure: shell, tube bundle, tube sheet, baffle baffle and head. One fluid flows inside the tube, and its stroke is called the tube side; the other fluid flows outside the tube, and its stroke is the shell side. The wall surface of the tube bundle is the heat transfer surface.
Baffle baffle: In order to increase the flow velocity of the shell-side fluid, a certain number of baffle baffles that are perpendicular to the tube bundle are often installed in the shell. The baffle not only can prevent the fluid from short circuiting and increase the fluid velocity, but also force the fluid to cross-flow through the tube bundle multiple times according to the prescribed path, which greatly increases the turbulence.
a. missing shape
b. disc shape
There are two types of baffle baffles: disc-shaped and disc-shaped. The former is more commonly used.