Common Types of Heat Exchangers Explained
Heat Exchangers are pieces of equipment used to transfer heat from one medium to another. The medium is usually fluid, but sometimes even solids are used. The types of fluids and pressures will designate what kind of design to use.
There are different types of heat exchangers, and they can be distinguished in the way they transfer heat and how the fluids flow. These are some of the heat exchangers available.
1). Plate Heat Exchanger
Plate and frame heat exchangers (PHEs) are commonly used in the food and beverage industry, although there a variety of other industries that uses them. One of the primary advantages of PHEs is that they tend to be more efficient than alternative heat exchangers. This is due to the design of the units as they have a large surface area, which enables a greater heat transfer rate. This is due to the variable heat transfer surface. Plates can be easily removed or added to reach desired requirements.
Plate heat exchangers are not just used for cooling – they are also used in heating processes. This is because the fluids flow in alternation from hot to cool. This gives them the ability to either heat the plate or cool them depending on the required needs.
2). Shell and Tube Heat Exchanger
This type of exchangers consists of several tubes. The tubes are divided into two, the tubes to be cooled or heated and the tube to cool or heat. These tubes are arranged close to each other to enable heat exchange.
As the fluid flows through one set of the tubes it either extracts or applies heat to the other tubes. The first set can be used to discard heat from the other tubes in case the application is used for cooling. For heating purposes the first set brings heat and transfers it to the other tubes. The tube thickness determines how effective this exchanger is. A thin tube enables a faster loss of heat or gain of heat.
3). Tubular Heat Exchanger
This exchanger is almost similar to tube heat exchangers. The difference is that the tubes used in a tubular heat exchanger are concentric. One tube is placed inside another. One of the tubes carries the hot fluid, and the other carries the cold fluids. Heat exchange is done while the fluids flow simultaneously.
4). Fin Type Heat Exchanger
These heat exchangers are almost similar to plate exchangers except they have fins fitted between the plates. The fins are used to hold the plates together and also to increase the surface area. With a large surface area, heat transfer is made easier and more efficient.
Fin type heat exchangers are mostly used in the aircraft due to their simplicity. They can also be used in car and railway engines.
5). Spiral HX Heat Exchanger
The spiral heat exchanger has two spiral shaped metal plate and two fluid passages. The fluid only has a single passage, unlike the multi-pipe heat exchanger. This enables faster and easier flow of heat.
The fluid flows in a counter flow enhancing its efficiency in heat exchange. This type of heat exchanger is used in the following industries.
- Fat & Oil Refinery
- Oil & Gas
6). Brazed (fully welded) Heat Exchanger
This type of exchanger consists of corrugated brazed plates specially designed to increase heat exchange. The plates are well arranged to form two alternate layers. To further increase its efficiency, the fluid is made to flow in different directions. The fluids have a counter flow in the plates to enhance heat transfer between them.
This type of exchanger is used in the following industries.
- Industrial process heating or cooling
- Hydraulic oil coolers
- Engine Coolers
- Condensers / Heat Pumps
- Marine Condensers
Regardless of the heat exchanger type, it is important that you regularly maintain your unit to avoid leaks and pressure spikes, which can result in costly downtime or contamination. You’ll also want to make sure you have an emergency plan in case your unit(s) go down.
If you have any issues with your heat exchanger or would like to learn more about our PHE services, please contact us or request a quote. We specialize in plate and frame heat exchangers across multiple industries.