When it comes to heat exchangers, many different types are used in various industries. In this blog post, we will be discussing the different ways heat exchangers are used in industry and what makes them so valuable.
What are industrial heat exchangers?
Industrial heat exchangers are devices used to transfer heat between two fluids or gasses. The fluids can be either liquid or gas at different temperatures.
In most heat exchangers, a heat transfer surface separates the fluid, which incorporates a wide range of different flow configurations to achieve the desired performance in different applications.
There must be a temperature difference for the heat to transfer, and heat always flows from hot to cold.
There are many different heat exchangers used for heat transfer, but the most common type used in industry is the gasket plate heat exchanger.
A plate-type heat exchanger is composed of a series of plates that are placed between two hot and cold fluids. The heat from one fluid is transferred to the other fluid through the plates.
Plate heat exchangers are very efficient and can be used for various applications. They are often used to heat or cool fluids, and they can also be used to heat or cool gases.
Where are heat exchangers commonly used?
Heat exchangers are used in various industries, such as chemical, petrochemical, pharmaceutical, power generation, and food processing.
Heat exchanger systems are used in many engineering applications, including heating, air conditioning, heating and refrigeration units, electrical systems, chemicals processing systems, and food processing systems.
Just a selection of sectors that use heat exchangers in industry applications
- Food and beverage industry
- Pharmaceutical industry
- Chemical processing industry
- Industrial process cooling and heating
- HVAC systems
- Power plants and cogeneration
- District heating and cooling
- Geothermal heat pumps
Which heat exchanger is used most in industries?
The most widely used heat exchangers in many industries are plate (PHE), also known as gasketed heat exchangers, and shell and tube heat exchangers.
What are the different types of heat exchangers?
- Plate heat exchanger (PHEs)
- Finned tube heat exchanger
- Shell and tube heat exchangers
Plate heat exchangers (PHEs)
One of the most common heat exchangers used in industry is the plate heat exchanger.
Plate heat exchangers are made up of metal plates placed between two end covers. These plates are then sealed with gaskets, and the entire unit is welded together. The spaces between the plates are where the heat is transferred from one fluid to the other.
PHEs are very efficient and can be used for various industrial applications. They are often used to heat or cool fluids, and they can also be used to heat or cool gases.
What are some of the advantages of using a plate heat exchanger?
Plate heat exchangers are commonly used in these industries because of their ability to transfer heat quickly and efficiently. Additionally, they are easy to maintain and can be customized to meet the specific needs of each application.
There are many advantages to using plate heat exchangers. They are very efficient, have a small footprint, and are easy to maintain. Plate heat exchangers are also very versatile and can be used in many industries.
Some of the benefits of industrial plate heat exchangers include;
- High heat transfer efficiency
- Compact design
- Easy to clean and maintain
- A PHE be customized to meet specific needs
- Durable and long-lasting
What is a shell and tube heat exchanger?
Double Pipe Heat Exchangers are a form of shell and tube heat exchanger.
Double pipe heat exchangers employ the simplest heat exchanger design and configuration, consisting of two or more concentric, cylindrical pipes or tubes (one larger tube and one or more smaller tubes).
Some of the types of shell and tube heat exchangers available include helical coil heat exchangers and double pipe heat exchangers, and some of the applications include preheating, oil cooling, and steam generation.
Advantages of shell and tube heat exchangers
- They can be designed and produced to sustain tremendous amounts of pressure.
- Shell and tube heat exchangers are extremely versatile and steady.
- They may be made and installed to endure extremely low and extremely high temperatures.
- Resistant to thermal shocks.
- There are no size restrictions.
Finned tube heat exchanger
A finned tube heat exchanger consists of a series of tubes placed inside a housing. The housing has fins that are attached to the outside of the tubes.
The heat from the hot gas is transferred to the fins and then to the fluid inside the tubes. This heat exchanger is very efficient and can be used in many industries.
Where would you use a finned tube heat exchanger?
Finned tube heat exchangers are often used for heat recovery in processes that exhaust hot gasses. The heat in the gas is transferred into a liquid, usually water or thermal oil. The heated liquid can be used in an application where you would normally use even more energy to heat it.
Advantages of using a finned tube heat exchanger
- Increase heat transfer rate – The surface area of contact in a finned tube increases. This increases the heat transfer rate.
- Improve heat transfer coefficient – The heat transfer coefficient is how well something transfers heat. In an ordinary tube, the outside area is about the same as the inside area. This means that the fluid with the lowest heat transfer coefficient will control how much heat is transferred. A finned tube increases the surface area a lot. This is helpful when the heat transfer coefficient of the fluid inside the tube is greater than that of the fluid outside the tube.
- The project will be less expensive because the equipment is smaller – Finned tubes can increase the surface area significantly. This means that you can use fewer tubes in an application, which will reduce the size of the equipment needed. This can lead to a decrease in the project’s cost in the long run.
Understanding heat exchangers and flow arrangement
The arrangement of the hot and cold fluid’s flow within the heat exchanger is another major way of categorizing them.
There are four principal flow configurations employed by heat exchangers;
- Countercurrent flow – Countercurrent flow heat exchangers, also known as counter-flow heat exchangers, are designed such that the fluids move antiparallel (i.e., parallel but in opposite directions) to each other within the heat exchanger.
- Cocurrent flow – In cocurrent flow heat exchangers, the streams flow in the same direction and parallel. This is less efficient than countercurrent flow, but it does provide a more uniform wall temperature.
- Crossflow – Crossflow heat exchangers are more efficient than countercurrent flow exchangers but less efficient than parallel flow exchangers. In these units, the streams flow across each other at right angles.
- Hybrid flow – Hybrids of the different types of flow are often found in industrial heat exchangers. These are combined crossflow/counterflow heat exchangers and multi-pass flow heat exchangers.
Cocurrent flow industrial heat exchangers also referred to as parallel-flow heat exchangers, are heat exchanging devices in which the fluids move parallel to and in the same direction.
Although this configuration typically results in lower efficiencies than a counterflow arrangement, it also allows for the greatest thermal uniformity across the walls of the heat exchanger.
Direct contact heat exchangers bring the hot and cold fluids into direct contact within the tubes rather than relying on radiant heat or convection.
Heat exchanger fouling
Fouling is the deposition of unwanted materials on heat exchanger surfaces.
Fouling can reduce heat transfer efficiency and, in extreme cases, cause failure of the heat exchanger.
Fouling occurs when liquids or gases come into contact with heat exchanger surfaces.
The fouling material may be a solid, liquid, or gas.
Fouling can be classified as either organic or inorganic.
Organic fouling is caused by the deposition of organic materials, such as oils, greases, and tars. Inorganic fouling is caused by the deposition of inorganic materials, such as scale (calcium carbonate), silt, and rust.
Fouling can also be classified as either reversible or irreversible. Reversible fouling is caused by materials that can be removed from heat exchanger surfaces without damaging the surface. Irreversible fouling is caused by materials that cannot be removed without damaging the heat exchanger surface.
Heat exchangers are important in many industrial applications because they allow heat to be transferred between two fluids without coming into direct contact. This is important because it allows heat to be transferred more efficiently, and it also prevents fouling, which can reduce heat transfer efficiency.
As plate heat exchangers are crucial for industrial efficiency, manufacturers need to understand how they work and the benefits they provide.
Heat exchangers are used in various industries, including food processing, chemical production, and pharmaceutical manufacturing. In these industries, heat exchangers help to improve the efficiency of processes by transferring heat between fluids.
Keeping your heat exchanger running smoothly is crucial for maintaining efficiency in your industrial process. If you suspect fouling, contact an expert who can help you clean your heat exchanger and restore it to working order.
Do you have any questions about heat exchangers in industry? Get in touch with us today to learn more about how we can help you improve your process efficiency. We’re always happy to chat.