Shell and Tube Heat Exchangers

Shell and Tube Heat Exchangers

The shell and tube heat exchanger is one of the most common heat exchangers used for industrial purposes. Let us guide you through some of the important aspects of shell and tube heat exchangers.

What are Shell and Tube Heat Exchangers?

A shell and tube heat exchanger is a device that consists of a collection of tubes surrounded by a cylindrical shell within which heat transfer takes place. In a shell and tube heat exchanger, one fluid flows through the tubes and another over the tubes in the area enclosed by the shell.

The fluids inside the heat exchanger are of different temperatures and heat transfer takes place through the tube walls. The hot process fluid transfers heat to the coolant fluid. These fluids can either be in gaseous or liquid form. To ensure efficient heat transfer, many tubes are used to increase the surface area on which the heat transfer process takes place.

How do Shell and Tube Heat Exchangers Work?

When one fluid passes through the tubes and another over the tubes, they exchange heat through the tubes made of thermally conductive materials. These materials include aluminum, steel, and copper. Selecting a shell and tube heat exchanger made from a suitable material is imperative. For instance, stainless steel is strong, durable, and can resist corrosion.

This industrial heat exchanger has an inlet and an outlet. The fluid in the tube flows through the tubes and exits through an outlet. On the other hand, the fluid surrounding the shell enters through an inlet, passes over the tubes, and exits through an outlet.

The fluid flow in shell and tube heat exchangers can be parallel-flow, counter-current flow or cross-flow depending on the type of heat exchanger you need.

Types of Shell and Tube Heat Exchangers

There are several types of shell and tube heat exchangers categorized according to their design. They include:

U-tube heat exchanger

This type of heat exchanger contains several tubes that bend to form a U-shaped pattern hence its name. This heat exchanger allows for maximum thermal expansion due to the U-shaped tubes. It is suitable for fluids with a large temperature difference, such as those used in industrial boilers.

Fixed tube sheet heat exchanger

This heat exchanger features tubes that are attached to tube sheets. The tube sheets are then firmly welded onto the shell. This allows for minimal thermal expansion, which can’t withstand high temperatures. The heat exchanger could be damaged if the temperature difference between the two fluids is too high.

Floating head heat exchanger

A floating head heat exchanger has tubes that are attached to a tube sheet. This tube sheet is then fixed to the shell on one side. On the other side, the tube sheet is not permanently fixed to the shell and is allowed to float.

This design gives allowance for thermal expansion and can withstand a huge temperature difference. The floating head exchanger is also relatively easy to clean and maintain.  

Applications of Shell and Tube Heat Exchangers

Shell and tube heat exchangers can be used in various industrial applications. This is due to its simple design. Below are several industrial applications that use shell and tube, heat exchangers.

  • Power plants
  • Fertilizer industries
  • Marine application
  • Pulp and paper applications
  • Air processing and compressor cooling
  • Pharmaceuticals
  • Metals and mining

Pros and Cons of Shell and Tube Heat Exchangers

Let us look at some of the benefits and limitations of using shell and tube heat exchangers.

Pros

Cost effective

Shell and tube heat exchangers are relatively inexpensive compared to other heat exchangers. If you are working within a budget, shell and tube heat exchangers might be the perfect fit.

Withstands high temperature and pressure

Shell and tube heat exchangers can resist high temperature and pressure unlike some types of heat exchangers. Shell and tube heat exchangers are reliable heat exchangers that can maintain the operations of your factory even in high temperatures.

Easy to clean and maintain

Shell and tube heat exchangers are relatively easy to clean and maintain since they have a simple design and can easily be dismantled.

Cons

Large in Size

Shell and tube heat exchangers have large dimensions and might not be suitable for small spaces. These heat exchangers might also take up too much space, allowing little space to carry out other activities.

Shell and tube heat exchangers are efficient heat exchangers that can be used in a variety of applications. They are also available in different design types, which you can choose from. For more assistance, get in touch with us today.