All You Should Know About Heat Exchangers

Heat Exchangers Introduction:

A heat exchanger is a device whose prime function is to transfer the heat between one liquid to another. Heat exchanger manufacturers claim them to be the most versatile kind of thermal exchangers having a high-efficiency rate. These devices are having the wide range of application scope and their usage is not only limited to the heating applications like space heaters and others but are vastly employed in cooling applications as well such as refrigerator, air conditioners, industrial chillers and etc.

Heat Exchangers Working Principle:

Heat exchanger manufacturers explain their working principle as the device enables the heat from one liquid or gas to transfer to the other liquid or glass without two fluids getting mixed into each other. In easier words, heat exchangers transfer heat without transferring the liquid or gas that was initially carrying heat.

It is also important to understand that not all heat exchangers are working on the principle of heat transfer from one liquid to another, but sometimes also use other mediums to do so.

Different Kinds of Heat Exchanger:

Heat exchangers are commonly distinguished with the help of the direction of the liquid that is flowing through, making a heat exchanger either cross flow, parallel flow, and counter current. In parallel flow both the liquids flow in the same direction entering and exiting from the same sides. In the cross flow, as the name suggests, the liquid flows in the perpendicular direction to each other. Whereas in the countercurrent variation, the liquid flows in opposite directions, meaning one liquid exiting from where the other liquid will be entering.

Heat exchangers are also classified based on other factors rather than the direction of fluid as well. Below are some of the most popular types of heat exchangers.

• Plate Heat Exchanger

• Shell and Tube Heat Exchanger

• Adiabatic Wheel Heat Exchanger

• Regenerative Heat Exchanger

Plate Heat Exchanger:

Plate heat exchanger incorporates thin metal plates, usually plates made out of stainless steel. Using a small rubber structure, these plates are held together with a little space between them. Each plate is designed with openings that allow the liquid flow between them and extract the heat from plates as it flows by.

Shell and Tube Heat Exchanger:

Shell and Tube Heat Exchanger contains various multiple tubes through which the liquid is allowed to flow. These tubes are divided to perform two different functions. The first set is comprised of the liquid to be heated or cooled. And the second set of tubes are designated to trigger heat exchange by either removing the heat from the first set or transferring its own heat away in order to cool down its temperature.

Adiabatic Wheel Heat Exchanger:

The adiabatic wheel heat exchanger uses an intermediate fluid that works as a medium to carry heat. This heat is then transferred to the heat exchanger unit. This kind is made up of a large wheel that performs rotation through the liquid for heat transfer.

Regenerative Heat Exchanger:

In a regenerative heat exchanger, the same liquid is made to pass through both sides of exchangers, which can be a plate, tube or shell heat exchanger. Since the liquid gets really hot, the exiting liquid transfers the heat to the incoming liquid and main a constant temperature. This is the best type of heat exchanger when it comes to energy saving as it works on the regenerative principles.

Heat Exchanger Applications:

Heat exchangers are very popular in electrical, mechanical and chemical systems. Their most common uses are found in ventilation systems, air conditioners, combustion engines, radiators, refrigerators and so on.

Expansion Joints and their Functions

Metal Bellows Expansion joint is a very essential elements to the piping systems. They are used as an alternative of expansion loops. Expansion joints main function is to absorb terminal movements and thermal expansions. They come in varying shapes and sizes with many choices of material.

Expansion joints are crucial in piping systems nowadays. A good piping system understands the functions of expansion joints and where to utilize them for maximum efficiency. They absorb shock, vibrations, reduce noise and take the heat of all the directional movements. Expansion loops can’t fulfill all these functions which is why Metal Expansion joints are used.

Elastomeric joints are unable to cater in extreme weather and pressure induced environments which is why need for expansion joints arises. They can withstand temperatures between 450 Fahrenheit to +2000 Fahrenheit. It can hold the pressure of 3000 psi.

Functional Capabilities of Metal expansion joints

Metal Bellows Expansion Joint while allowing the directional thermal movements, tone down the noise. Their ability to produce a discontinuation among piping system helps in noise and vibration reduction. Rotating parts of an equipment like centrifugal pumps produce unbalanced forces which causes noise. Expansion joints distort those forces and absorbs the energies.

Type 1: Absorption of directional movement and vibration

This type of expansion joint is designed for maximum thermal absorption as they are a major outcome in any piping system. Thermal factors may depend upon temperature, material of joints and size of pipes. They have exceptional resistance to shock which is caused by seismic events or pressure surges in piping systems. These movements are strong enough to emit forces which tend to limit stress of pipes.

Type 2: Spool shaped Expansion Joint
Spool shaped elastomeric joints are made up of tube carcass and cover. This is basically a leak proof lining. Its function is to protect the carcass to form a contact with the fluid. The material of tube should be able to fight temperature, chemical abrasions and acid fumes.

Conclusion:

The main role of metal expansion joints is the reduction of noise, stress and shock. They prevent the harm from external factors which could threaten the solemnity of a system. Misalignment of joints is the main problem that causes issues to a piping system. Expansion joints compensates for all the misalignments and increase the life of the piping system. All you need to know is the different types of expansion joints so that you may understand their application in different areas.