What Are Heat Exchangers and Why You Should Know About Them

Heat Exchangers

How many of us have ever considered how our central heating system works, why is it that our refrigerator is cold on the inside despite it being warm in the room on the outside or how does an air conditioning system work to cool a room. Have we considered our industrial and manufacturing processes, many of which operate on massive scales, requiring complex pieces of engineering and differing temperature requirements existing side by side. What prevents an engine from overheating?

These are questions that many a curious person may ask and for others, we take this technology for granted, never giving it a second thought but without it, we would not be able to drive to work, we would not be able to chill our foods and our houses would be very cold!

The mechanism that is used in the processes is known as Heat Exchanger. What is a heat exchanger? A Heat Exchanger really does as the name suggests, it is a device which allows the transfer of heat from one fluid to another without the fluids touching each other.

There are many types of heat exchangers and there are differing flow patterns within them but all of the heat exchangers essentially do the same job. It would very much depend upon the application as to what heat exchanger would best fit your process. Heat exchangers conserve energy and hence save businesses many thousands of pounds per year.

Two common types of heat exchangers would be the Shell and Tube Heat Exchanger and the Plate and Fin Heat Exchanger. Both produce the same result but use different processes.

Shell and Tube Heat Exchanger

This type of heat exchanger consists of an outer shell which can be made from different materials. Within the outer shell is placed tubes and fluid would be passed through the tubes. On the outside, within the shell, is passed a different fluid at a different temperature. This allows for the transfer between temperatures without the need for the fluids to come into contact with one another. A Shell and Tube Heat Exchanger is commonly used in high pressure applications.

Plate and Fin Heat Exchanger

This type of heat exchanger uses plates which are commonly made from steel or titanium and ‘fins’ which are placed between the plates. Gaskets are used to seal the plates. The plates are screwed to the fins to create a solid structure. In this type of heat exchanger, fluid streams at different temperatures pass through alternate layers, hence allowing for heat / cold transfer. This type of heat exchanger is very cost efficient and can be developed for use in a variety of applications. It is compact and easy to maintain hence making it a very popular choice for many applications.

It can help to have a basic understanding of heat exchangers so that when you are discussing your process requirements, this can be done from a point of knowledge, after all you are the one who knows your requirements best of all.

Image Credits: Heat Exchangers from sspopov/Shutterstock