The heat exchanger is a working unit with heat transferring from one to another medium. They can be separated by plates or walls of pipes, if one of the medium moves through the pipes. The larger the area of the separating surface, the more efficient the heat exchange is.
The choice of a heat exchanger should be made depending on the task it will perform, and on the required power, as well as on a number of some other conditions. For example, a device with pipes is more suitable for liquids, with a rotating heat exchanger for gases, and units with plates can be used for any medium.
Types of heat exchangers
According to the principle of operation, heat exchangers are divided into two types:
- Recuperative;
- Regenerative.
The regenerators allow mixing of the heating and heated medium, in case of recuperators there is no mixing, the medium are hermetically separated.
Types of heat exchangers
There are many types of heat transferring equipment. The following heat exchangers are widely used:
- Submersible. The device is equipped with a cylindrical coil, which is located in a chamber with liquid. These heat exchangers are used in conditions where boiling is allowed;
- Graphite. Cylinder for the passage of one medium is inside a rectangular block and is washed by another medium, passing crosswise. It is used for environments that cause increased metal oxidation (corrosion);
- Spiral. A metal sheet twisted in a spiral, requires gaskets or partitions. Such a heat exchanger is difficult to maintain, but is efficient and has a small weight;
- Shell-and-tube. One medium passes through the pipes located in the shell, the pipes are washed by another medium. Good for liquids;
- Plate. Medium are separated by plates, the number of channels varies from two (one for each medium) and more. Plate heat exchangers are more compact, efficient, and suitable for different medium.
