Exchangers are one of the most significant and utilized pieces of process equipment in industrial settings. As the name implies, industrial heat exchangers are industrial equipment that exchanges or transfers heat from one medium to another. It uses thermal energy exchange to send energy between two or more mediums at different temperatures. However, there are many heat exchangers, each with its benefits and drawbacks. They specialize in certain applications and industries.
Plate and Frame Heat Exchanger
Gaskets separate parallel corrugated plates. They control the alternating flow of hot and cold fluids over the plate surfaces in plate and frame designs. The straightforward mechanical design allows for simple cleaning. It also provides for capacity modifications by adding or removing plates.
The plate heat exchanger is an exception to all other forms of heat exchangers that share a similar design. Heat is usually transferred between two fluids using metal plates. The plate is a metal casing with spaces inside that serve as passageways for fluids to flow through. Because it has a larger surface area in contact with fluids, it has higher heat transfer rates than other types.
Although plate heat exchangers are more expensive, the increased efficiency is a significant benefit. Because of its endurance and low replacement rates, this heat exchanger is suitable for power plants. Industries mostly use plate heat exchangers in liquid-to-liquid applications. For example, hot process water with chemicals/contaminants heating cold mains water to provide clean hot water.
Double Pipe Heat Exchangers
Double pipe heat exchangers are like shell and tube heat exchangers. They use the most basic heat exchanger design and structure. It consists of two or more concentric, cylindrical pipes or tubes (one larger tube and one smaller tube). The shell and tube heat exchanger’s design lets one fluid flow through the smaller tube(s). The fluids remain separated and flow via their channels throughout the heat transfer process. However, double-pipe heat exchangers provide some design flexibility. For example, heavy equipment manufacturers can design with concurrent or countercurrent flow arrangements. In addition, they can be used modularly in a system’s series, parallel, or series-parallel combinations.
Shell and Tube Heat Exchangers
Shell and tube heat exchangers are the most adaptable of all heat exchanger types. They are the most known type of heat exchangers. They consist of a single tube or sequence of parallel tubes (i.e., tube bundle). A sealed, cylindrical pressure vessel (i.e., shell) encases these tubes. Heat moves between fluids that travel through a bundle of tubes and fluids within a huge shell vessel. The vessel surrounds the tubes in shell and tube heat exchangers. Tubes inside the shell allow for the processing of more viscous fluids than a plate and frame heat exchanger. Helical coil and double pipe heat exchangers are two types of shell and tube heat exchangers. Their use includes preheating oil cooling and steam generation.
These designs are typically utilised for high-pressure applications. But you can also use them in vacuum conditions when you require a structure that can withstand high stresses. For example, a shell and tube containment element may be better for hot gasses compared to a finned tube bank. This is especially if the gases are unpleasant to health or need restraining from the atmosphere. Industries use shell and tube heat exchangers in the oil, gas, and chemical industries.
Finned Tube Heat Exchanger or Air Cooled Heat Exchanger
This heat exchanger is also referred to as an air-cooled heat exchanger (ACHE) or dryer. It works by circulating gas or air over or over the piping to cool the fluid. The efficiency of these units is due to the enlarged surface – the fins. The fins protrude into the air/gas flow, boosting the structure’s heat transfer ability.
These tube heat exchangers are often utilized in systems that exhaust hot gases for heat recovery. The exchanger transfers the heat in the gas to a liquid, water, or thermal oil. The industry can then use the heated liquid in an application that would ordinarily require much more energy to heat. Chemical applications, steam cooling, textile processing, grain drying, and food processing enjoy ACHEs. Because air is the most often utilized process fluid, ACHEs have many applications.
Condensers, Evaporators, and Boilers
Boilers, condensers, and evaporators are also heating exchangers. But, they use a two-phase heat transferring mechanism. One or more fluids in a two-phase heat exchanger undergo phase change during the heat transfer. As a result, they either move from a liquid to a gas or from a gas to a liquid. For example, condensers are heat exchangers that take a heated gas or vapor and cool it to the point of condensation. They then convert it from a gas to a liquid. In evaporators and boilers, on the other hand, the heat transfer process converts fluids from liquid to gas or vapor.
There’s a wide variety of heat exchangers available. But, the application’s requirements determine the design and usefulness of each type in transferring heat between fluids. Therefore, these variables influence the best design of the intended heat exchanger.
