Sunday, November 9, 2014
Wednesday, July 23, 2014
How to design a tubular heat exchanger?
At HRS Heat Exchangers, designing tubular heat exchangers is our daily business. In this text we would like to describe you the various steps of the design process.
Step 1: Analyzing the application
When an enquiry for a heat exchanger is received, the first step consists in analyzing the application. Is it a food industry application? Is it an industrial one? The design engineer must define correctly the type of heat exchanger that is necessary and complies with the requirements of the application. As can be seen in our product portfolio, various types of heat exchangers can be used.The design temperature, design pressure and maximum allowable pressure drop must be defined for the product and service fluids.
Thursday, July 10, 2014
Types of Heat Exchangers
Heat exchangers are devices whose primary responsibility is the transfer (exchange) of heat, typically from one fluid to another. However, they are not only used in heating applications, such as space heaters, but are also used in cooling applications, such as refrigerators and air conditioners. Many types of heat exchangers can be distinguished from on another based on the direction the liquids flow. In such applications, the heat exchangers can be and be parallel-flow, cross-flow, or countercurrent. In parallel-flow heat exchangers, both fluid involved move in the same direction, entering and exiting the exchanger side by side. In cross-flow heat exchangers, the fluid paths run perpendicular to one another. In countercurrent heat exchangers, the fluid paths flow in opposite directions, with each exiting where the other enters. Countercurrent heat exchangers tend to be more effective than other types of exchangers. Aside from classifying heat exchangers based on fluid direction, there are types that vary mainly in their composition. Some heat exchangers are comprised of multiple tubes, whereas others consist of hot plates with room for fluid to flow between them. It’s important to keep in mind that not all heat exchangers depend on the transfer of heat from liquid to liquid, but in certain cases use other mediums instead.
Types of Heat Exchangers
Shell and tube heat exchangers are comprised of multiple tubes through which liquid flows. The tubes are divided into two sets: the first set contains the liquid to be heated or cooled. The second set contains the liquid responsible for triggering the heat exchange, and either removes heat from the first set of tubes by absorbing and transmitting heat away—in essence, cooling the liquid—or warms the set by transmitting its own heat to the liquid inside. When designing this type of exchanger, care must be taken in determining the correct tube wall thickness as well as tube diameter, to allow optimum heat exchange. In terms of flow, shell and tube heat exchangers can assume any of three flow path patterns.
Plate heat exchangers consist of thin plates joined together, with a small amount of space between each plate, typically maintained by a small rubber gasket. The surface area is large, and the corners of each rectangular plate feature an opening through which fluid can flow between plates, extracting heat from the plates as it flows. The fluid channels themselves alternate hot and cold fluids, meaning that heat exchangers can effectively cool as well as heat fluid—they are often used in refrigeration applications. Because plate heat exchangers have such a large surface area, they are often more effective than shell and tube heat exchangers.
Regenerative Heat Exchanger
Adiabatic Wheel Heat Exchanger
Source: www.thomasnet.com
more on heat exchangers:Double pipe heat exchanger , shell and tube heat exchanger
more on heat exchangers:Double pipe heat exchanger , shell and tube heat exchanger
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