- What is the purpose of countercurrent exchange?
- Why are gills rich in blood?
- Why do fish swim against the current?
- Why the rate of oxygen supply to human cells is faster than the rate of oxygen supply to fish cells?
- What is effectiveness of fin?
- What is counter flow cooling tower?
- How do I choose a heat exchanger?
- What are the two types of heat exchangers?
- Do humans use countercurrent gas exchange?
- Why is one way flow an advantage to fish?
- Why is countercurrent flow more efficient in fish?
- What type of flow has better heat transfer in a coil?
- What is counter current principle?
- What is fouling factor?
- Why is countercurrent exchange more efficient?
- What is counter flow system?
- What is the most effective heat exchanger?
- Why are the most efficient heat exchangers made up of many metal plates rather than pipes?
- Do lungs use countercurrent exchange?
- What is the major difference between Shell and Tube vs plate and frame heat exchangers?
- Why is counter flow more effective?
What is the purpose of countercurrent exchange?
The purpose of counter current exchange is to maintain a concentration gradient between the two fluids in order to maximize movement from one fluid to the other.
The opposite of counter current exchange occurs in concurrent exchange when two fluids flow in the same direction..
Why are gills rich in blood?
The water enters the mouth and passes through the feathery filaments of the fish’s gills, which are rich in blood. These gill filaments absorb oxygen from the water and move it into the bloodstream. … At the same time, waste carbon dioxide in the blood passes out through the gills into the water.
Why do fish swim against the current?
In nature, a fish must exert energy and swim against the current to avoid being swept downstream. In the aquarium the fish moves in the same direc- tion as the moving card, which might be viewed as a fixed object in the stream.
Why the rate of oxygen supply to human cells is faster than the rate of oxygen supply to fish cells?
This is because its body is used to breathing through gills. … Smaller fish and humans breathe faster than larger fish and humans because smaller fish and humans also have smaller lungs and gills, which have less capacity to store and process oxygen than bigger lungs and gills do.
What is effectiveness of fin?
Effectiveness of fin (εfin): It is defined as the ratio of the actual heat transfer that takes place from the fin to the heat that would be dissipated from the same surface area without fin.
What is counter flow cooling tower?
In a crossflow tower, air travels horizontally across the direction of the falling water whereas in a counterflow tower air travels in the opposite direction (counter) to the direction of the falling water. See Figure 1 and Figure 2 for a visual explanation.
How do I choose a heat exchanger?
3 Tips for Choosing the Right Heat ExchangerComprehensively analyze the application’s design. The first step to choosing the right heat exchanger for an application that’s already designed is to thoroughly analyze that design from multiple angles. … Measure the advantages of ambient cooling. … Consider consolidating thermal management needs.
What are the two types of heat exchangers?
What Are The Different Types Of Heat Exchanger?Finned Tube Heat Exchanger Or Air Cooled Heat Exchanger. Suitable for: air/gas to fluid. … Shell And Tube Heat Exchanger. Suitable for: fluid to fluid / fluid to gas. … Plate Heat Exchanger Or Gasket Plate Heat Exchanger. Suitable for: fluid to fluid / fluid to vapour.
Do humans use countercurrent gas exchange?
Countercurrent exchange uses Diffusion to passively (no energy required) transfer the oxygen across to the blood. … Fish have lower metabolic rates than humans, and so their oxygen requirements are much lower than mammals and can live without hemoglobin.
Why is one way flow an advantage to fish?
2. Because water is more vicious than air, it takes more energy to ventilate and swim through it. This causes an increase in demand for oxygen, and therefore fish have a continuous unidirectional flow of water over their gills for maximum diffusion efficiency.
Why is countercurrent flow more efficient in fish?
Fish utilise a counter-current system in order to maximise the amount of oxygen that can extracted from water. Water has a much lower oxygen content than air and as such fish need a much more efficient system that can extract a much higher proportion of oxygen from the surrounding water.
What type of flow has better heat transfer in a coil?
Each of the three types of heat exchangers (Parallel, Cross and Counter Flow) has advantages and disadvantages. But of the three, the counter flow heat exchanger design is the most efficient when comparing heat transfer rate per unit surface area.
What is counter current principle?
Countercurrent exchange is a mechanism occurring in nature and mimicked in industry and engineering, in which there is a crossover of some property, usually heat or some chemical, between two flowing bodies flowing in opposite directions to each other.
What is fouling factor?
The fouling factor represents the theoretical resistance to heat flow due to a build-up of a layer of dirt or other fouling substance on the tube surfaces of the heat exchanger, but they are often overstated by the end user in an attempt to minimise the frequency of cleaning. …
Why is countercurrent exchange more efficient?
Fish gills use a design called ‘countercurrent oxygen exchange’ to maximize the amount of oxygen that their blood can pick up. They achieve this by maximizing the amount of time their blood is exposed to water that has a higher oxygen level, even as the blood takes on more oxygen.
What is counter flow system?
the flow of water and blood in opposite directions across the gills of fish which ensures that blood meets water with the highest possible oxygen content. see COUNTERCURRENT EXCHANGE.
What is the most effective heat exchanger?
Plate exchanger is the most efficient due to turbulent flow on both sides. High heat-transfer coefficient and high turbulence due to even flow distribution are important. However, a plate heat exchanger regenerator is restricted to low viscosities. With high viscosities, a special tubular may be required.
Why are the most efficient heat exchangers made up of many metal plates rather than pipes?
Stainless steel is the metal of choice for constructing flat plate heat exchangers because it can bear high temperatures, does not corrode easily and is extremely strong as well as highly malleable.
Do lungs use countercurrent exchange?
Therefore, oxygen has a diffusion rate in air 10,000 times greater than in water. The use of sac-like lungs to remove oxygen from water would therefore not be efficient enough to sustain life. … Gills use a countercurrent flow system that increases the efficiency of oxygen-uptake (and waste gas loss).
What is the major difference between Shell and Tube vs plate and frame heat exchangers?
Plate heat exchangers are up to five times more efficient than shell-and-tube designs with approach temperatures as close as 1°F. Heat recovery can be increased substantially by simply exchanging existing shell-and-tubes for compact heat exchangers.
Why is counter flow more effective?
The exchanger is performing at its best when the outlet temperatures are equal. Counter flow heat exchangers are inherently more efficient than parallel flow heat exchangers because they create a more uniform temperature difference between the fluids, over the entire length of the fluid path.