Heat Exchangers

In these types of heat exchangers, two fluids exchange heat. One fluid is referred to as the tube-side fluid (which goes through the heat exchanger inside the tubes) and the other is the shell-side fluid (which goes through the heat exchanger in the shell, outside the tubes).

A straight tube heat exchanger is easier to clean than a U-tube heat exchanger, making it a better choice when the tube-side fluid could have a tendency to foul the tubing and require more regular maintenance.

The U-tube heat exchanger works well when the tubes and shell will have different thermal expansion characteristics because it can allow the tube and the shell to expand or contract independently.

Spiral heat exchangers are circular units containing a concentric spiral flow channel in a bulk fluid. Spiral heat exchanger flow may be counter-current or co-current. Spiral heat exchangers are particularly suitable for use with fluids that tend to cause fouling and clogging and to minimize pressure drop of ultra-high viscosity fluids.

Advantages are the high overall heat transfer coefficient, compact size, relatively low pressure drop, and ease of cleaning.

In plate heat exchangers, heat is transferred from one fluid to another through a flat metal heat exchanger plate, instead of through a heat exchanger tube wall. Sometimes referred to as plate and frame heat exchangers or flat plate heat exchangers, they are made up of a series of plates held together in a frame with a fixed space between each plate.

Hot fluid flows between alternate spaces between plates, The cold fluid flows through the other set of spaces between plates. Gaskets are used between plates to provide a seal. Plate heat exchangers work well when very large square footages are required in a small footprint.

• High value for overall heat transfer coefficient (U value)
• Compact design compared to shell and tube
• Can be taken apart for easy cleaning and maintenance

A brazed plate heat exchanger is a type of a plate heat exchange that does not need gaskets. Instead, it is brazed together using copper or stainless steel to give a strong, compact construction.

In scraped-surface heat exchangers, the product enters the cylinder at the bottom and flows upward. The heating or cooling medium travels in a counter-current flow through a narrow channel.

Rotating blades continuously remove product from the cylinder wall to ensure uniform heat transfer to the product. The product enters the cylinder in a corkscrew pattern in the same direction as the rotating part. This preserves product quality by providing a larger flow area, gentler product handling and reduced pressure drop across the inlet. The food product finally leaves the cylinder at the top. Ideal for products that are viscous, sticky or contain particulates.