Heat exchangers are used in a number of applications to transfer heat from one liquid to another. Often they are used to actually generate heat such as when used in small space heaters, but they also have a number of other applications in areas such as cooling, where they can pull heat from a space. There are a number of different types of heat exchangers that can be used depending on the need. Here are four of the most common types of heat exchangers.
Plate and Frame Heat Exchangers
Plate and frame heat exchangers make use of embossed rectangular plates that are held together by a frame. These plates have holes in them that allow liquid to pass between the plates. Each of these holes has a fitted gasket on it so that the plates remain separated and so that the flow of the liquid can be controlled. Plate and frame heat exchangers are often used in applications involving foods because they are easy to disassemble and clean. Two plates can even be welded together to prevent any leakage between them.
Brazed Plate Heat Exchangers
Brazed plate heat exchangers are similar to plate and frame heat exchangers and are also often used when food is present. These exchangers, however, are designed to completely prevent leakage because all of the plates are brazed. The inlet and outlet ports are then welded together. These exchangers are smaller than shell exchangers and do not use any rubber gaskets, which means they can operate longer and at more extreme temperatures than plate and frame heat exchangers.
Welded Plate and Shell Heat Exchangers
While the shell and tube heat exchanger was one of the earliest models of heat exchangers, it has since been replaced with the more effective welded plate heat exchanger. This type of exchanger works the same as the shell and tube system, but because the tubes have been replaced by plates, it’s much more efficient. The plates are welded together and then placed inside the cylindrical shell. This exchanger uses no gaskets, allowing it to operate at extreme temperatures similar to the brazed plate exchangers. It’s also much smaller than traditional tube exchangers, taking up only about thirty percent of the space.
These exchangers can be used in a number of applications, including steam and district heating and as a refrigerant condenser.
Free Flow Plate Exchangers
Free flow plate exchangers are designed to be used in industries that deal with materials containing fibre and other types of pulp. These exchangers use plates that do not come into contact with each other. The small gap between the plates ensures that nothing will become trapped between them, while the entire system is designed to be easily cleaned without taking anything apart. Other advantages to using free flow plate exchangers include the fact that they can operate at incredibly high temperatures and that the plates are very rigid and strong. In addition to being used with pulpous materials, they may also be used to cool some foods such as tomato sauces, mustard, and yoghurt.