Knowledge Base > Which Heat Exchanger Suits Your Product Best?

Which Heat Exchanger Suits Your Product Best?

Introduction to Heat Exchanger

A heat exchanger is a device, which transfers thermal energy between two fluids at different temperatures. In most thermal engineering applications, both the fluids are in motion and the main mode of heat transfer is convection. Examples are automobile radiators, condenser coils in the refrigerator, air conditioners, solar water heaters, chemical industries, domestic boilers, oil coolers in a heat engine, and milk chillers in pasteurizing plants.

Classification according to construction:

  • Plate Type Heat exchangers
  • Shell and Tube heat exchanger
  • Scraped surface heat exchanger

Plate-type heat exchanger

A plate heat exchanger is used to transfer heat energy from one fluid to another. These fluids never encounter each other due to being separated by the heat exchanger. Typically, a plate heat exchanger will consist of several parallel plates positioned above each other, thus creating a passage in which the fluid can flow between.

Figure1 ‑a Product flow in Plate Heat Exchanger

Working Principle

Shell and tube type heat exchanger

The shell and tube heat exchanger consists of a bundle of round tubes placed inside the cylindrical shell. Shell and tube heat exchangers transfer heat between a bundle of tubes surrounded by a large shell vessel. Tubes enable the processing of fluids that are more viscous or contain more particulate or larger matter. Fluids that run through the tubes exchange heat with fluids that run over the tubes contained by the shell. The baffles provide support to tubes and deflect the fluid flow normal to tubes.

Figure1 ‑b Product Flow in Shell and Tube Heat exchanger

Working Principle


Scraped Surface Heat exchangers
Some processes require heat transfer that prevents fouling from viscous and sticky products. In those processes, scraped surface heat exchangers are the right choice because of their ability to process fluids that include a high number of particulates or high viscosity. Scraped surface heat exchangers are often more expensive than other exchangers but work more efficiently in applications where other options would be ineffective.
Figure1‑c Product Flow in the scraped surface heat exchanger

Working principle


Comparison between plate heat exchanger, Shell and tube exchanger, and scraped surface exchanger
CharacteristicsPlate Heat ExchangerShell and Tube ExchangerScraped surface Exchanger
CostInexpensive compared with other designsInexpensive compared with other designsRelatively more expensive than other designs
CleaningExcellent CIP-abilityExcellent CIP-abilityCIP-ability is lower than in other designs
Heat regenerationHigh heat regenerationMedium heat regenerationNo heat regeneration
CapacityEasy to increase/decrease capacityDifficult to expand capacityDifficult to expand capacity
FootprintSmaller footprint than other designsLarger footprint than plate-and-frame designsSmaller footprint than other designs
PressureLow operating pressureHigh operating pressureHigh operating pressure
FluidityNot for use with highly viscous or large particulate fluidNot for use with highly viscous products or products with large particulatesHighly effective with viscous products or products with large particulate fluids
PressureHigh TurbulenceMedium operating pressureNone
ApplicationsPlate heat exchangers are commonly used for beverage, beer, wort, eggs, sauces, and most dairy processingShell and Tube heat exchangers areused for pulpy juices, ketchup, and oil refineriesScraped surface exchangers are commonly used for Ketchup, Mayonnaise, Spreads and fillings, Sauces and puddings, Baby food

Conclusion

The article was an attempt to deliver all the essential information about what Heat Exchanger is and which type of Heat Exchangers is suitable for your product. Not many documents are available that simplify heat exchanger and compares different aspects of a heat exchanger.

This image has an empty alt attribute; its file name is Authors-note-1.png
Author: Surabhi Soral is a Food Technologist and passionate about setting things right in the first go. She is a Consultant at Food Safety Works and heads the the regulatory and compliance team.

Leave a Comment