How does a Shell and Tube Heat Exchanger work?
Shell and Tube heat exchangers are a specific kind of heat exchanger that include bundles of precisely spaced tubing compressed within a sizable cylindrical casing, or shell. Heat exchange is the process of transferring heat from one similar material or medium to another. Shell and tube heat exchangers are the most common type of heat exchanger design. They are categorized based on things like their performance qualities, tube type, material of construction, and other traits.
The shell and tube heat exchanger uses intermediate thermal contact between two fluids. This form of heat exchanger is made up of a tube bundle and an outer shell. The fluid in the tube bundle and shell are at two different temperatures. The driving factor behind the exchange of heat is this temperature difference. The tube bundle may include a variety of tubes, including plain tubes, spiral tubes, and tubes with fins. These tubes can be arranged in a variety of ways, including a U-shaped configuration, a fixed tube configuration, and a floating head arrangement.
High-pressure applications are perfect for these kinds of heat exchangers due to the inherent construction qualities of the setup. Large chemical plants and oil refineries are where they are most frequently used. These heat exchangers offer a straightforward design, cheap initial investment costs, steady performance, and minimal maintenance expenses. Even so, compared to plate heat exchangers with comparable heat exchange capacities, these heat exchangers demand greater installation space.
The design and operation of a shell and tube heat exchanger is simple. One fluid flows through the tube bundle, while the other flows through the shell. These flows are usually set up in a counter-current flow path to maximize heat transfer. The fluids exchange heat with one another through the tubing bundle walls as they move. According to the laws of thermodynamics, heat is transferred from the hot liquid to the cold liquid. This allows for precise heating or cooling of the process fluid using a heating or cooling medium, usually steam or water. The overall surface area of the tubing bundle, temperature difference, thermal conductivity of the tube material, thickness of the tube walls, and physical properties of the fluids, and flow rate of the fluids determines the heat transfer rate of the heat exchanger. Shell and tube heat exchangers have several advantages and benefits over other types of heat exchangers.
The main advantages of shell and tube heat exchanger are as follows:
- Compared to plate heat exchangers, shell and tube heat exchangers are generally less expensive.
- These heat exchangers are simple to build and need little maintenance.
- Shell and Tube heat exchangers can be designed to allow for a non-homogeneous flow of fluids, such as a bubbly liquid or slurry.
- These heat exchangers can operate over a wide variety fluid densities and viscosities.
- In applications requiring high pressure and temperature, they are preferable to plate heat exchangers.
- Compared to plate heat exchangers, tubular heat exchangers have a lower pressure drop.
- Compared to plate heat exchangers, shell and tube heat exchangers are less likely to clog and foul.
- The design of shell and tube heat exchangers is both reliable and adaptable.
Most often in the chemical processing sector, shell and tube heat exchangers are used to heat, cool, condense, and evaporate highly corrosive liquids and gases. Because of their adaptability to a wide range of temperatures and pressures, shell and tube heat exchangers are among the most common types of heat exchangers. Niche FPP is the original fluoropolymer heat exchanger manufacturer and has had heat exchangers in process since the 1960’s!