SHELL AND TUBE HEAT EXCHANGER –
A Heat exchanger is an exchanger design used to transfer or swap the heat from one matter to the other. Shell and tube heat exchanger is also a type of heat exchanger and it comes to its one of its designs. This shell and tube heat exchanger is most commonly used heat exchanger used in many oil refineries and thermal processes. This shell and tube heat exchanger is commonly employed for high pressure applications. The heat exchanger consists of two names in the main name, namely shell and tube. So we can easily conclude that the shell and tube heat exchanger is composed on tubes and shells in it for the transfer of the heat energy.
A shell and tube heat exchanger consists of large number of tubes in a large pressure vessel. One type of fluid runs in the tubes and the other type of fluid runs in the shell. The tube may be of any type and are likely to be plain and longitudinal but less finned. The Shell and Tube heat exchanger consists of two fluids. The fluid may be liquid or gas depending on the temperature and the type of liquid. The liquids may enter from the same direction or different direction into the shell and tube heat exchanger.
The heat is transferred from the tubes inside the shell and the fluid in the shell. The more will be the efficiency of the shell and tube heat exchanger with more number of tubes. The other reason to use more number of tubes in that it reduces the heat transfer waste. This is very efficient and can be used in many situations. When the flow of fluids is from the same direction, more heat transfer takes place but when the flow of fluids is from opposite directions, less heat transfer takes place.
There are two types of heat exchangers.
- Heat Exchangers with one phase
- Heat Exchangers with two phases
The heat exchangers with one phase can consist of any fluid that is liquid or gas. The heat transfer cannot take place when the conversion of the phase takes place, i.e., from liquid to gas or gas to liquid. But in the heat exchangers with two phases, the heat transfer will be more efficient than the first one and heat transfer can also take place by converting the water to gas by boiling or converting the liquid to gas by heating.
The shell and tube heat exchanger will also be U shape and consist of inlet and outlet at the same point but two points. The shell consists of the inlet at the opposite direction as the tubes. When the fluid moves in the tubes bundle, the other fluid moves from the shell side. The heat exchange occurs between them efficiently if it is a heat exchanger with two phase and shell and tube heat exchanger.
The heat exchanger may also be the straight tube heat exchanger with one pass tube side and the straight tube heat exchanger with two pass tube side. The selection of material must be in such a way that more heat transfer takes place, i.e., the material should have more thermal conductivity.