Is countercurrent flow more efficient than concurrent?
When you take the LMTD (logarithmic mean temperature difference) in the 2 cases, the value is higher in a counter current flow than a co current flow. As we know that heat transfer depends largely on the temperature difference, counter current flow is better.
What is difference between concurrent and countercurrent?
In concurrent exchange the two fluids move in the same direction as they pass through the pipes. In countercurrent exchange the fluids move in opposite directions.
Why is countercurrent more efficient than co current?
The maximum amount of heat or mass transfer that can be obtained is higher with countercurrent than co-current (parallel) exchange because countercurrent maintains a slowly declining difference or gradient (usually temperature or concentration difference).
Is Co current or counter current more efficient?
Overall, the counter-current heat exchanger is more efficient compared to the co-current heat exchanger, and is more widely used in the chemical process industry.
What is meant by effectiveness by NTU method?
The effectiveness ( ), is the ratio between the actual heat transfer rate and the maximum possible heat transfer rate: where: Effectiveness is a dimensionless quantity between 0 and 1.
Which heat exchanger flow type is the most efficient?
Counter flow heat exchangers
Counter flow heat exchangers are the most efficient of the three types. In contrast to the parallel flow heat exchanger, the counter flow heat exchanger can have the hottest coldfluid temperature greater than the coldest hot-fluid temperature.
What is a concurrent flow?
(definition) Definition: A multi-commodity flow in which the same fraction of the demand of each commodity is satisfied.
How efficient is a heat exchanger?
Typically, they can achieve efficiency rates of approximately 90%. This is higher than the efficiency offered by kettle, tubular, spiral or shell and tube heat exchangers.
What is meant by concurrent and countercurrent exchange?
Concurrent and Countercurrent Exchange. These models involve the exchange of a dissolved material from a high concentration solution to a low concentration solution where the solutions are separated by a permeable membrane. This type of exchange is very common in biological and industrial applications. As an example,…
How to modify the concurrent flow model into a countercurrent flow model?
Modifying the concurrent flow model into a countercurrent flow model is simply a matter of switching the valves along one pipe to be flowing in the opposite direction. The values and meanings of all the parameters will remain unchanged.
What is the gradient of a countercurrent exchanger?
Countercurrent exchangers maintain a constant gradient along their length to ensure that exchange takes place along the entire length. Detailed Explanation of CountercurrentExchange No exchange without gradient The greater the gradient the greater the rate of exchange
What are the disadvantages of co-current ductwork?
This is especially likely if the ductwork is not insulated. While a direct relationship exists between the material and process gas in the co-current design, the opposing flow of the solids and gas employed in the counter-current configuration makes it more difficult to control the temperature of the solids.