Countercurrent flow
produces the maximum concentration difference over the entire length of the membrane and allows recovery of a substantial portion of the most highly diffusive solute
while minimizing the transport of the less diffusive solutes.
What is the advantage of counter current flow over co current flow in a heat exchanger?
One of the great advantages of counter-current flow is
the possibility of extracting a higher proportion of the heat content of the heating fluid
. It is important to note that the LMTD value for counter-current flow is much larger than for cocurrent flow at the same terminal temperature (see Figure 1.9).
Is countercurrent flow efficient?
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.
What is a counter current flow and why is it so important?
This is the
way that a fish’s gills absorb the maximum amount of oxygen from the water
. Water flows in the opposite direction to the blood flow in the gills to ensure that there is always a higher concentration of oxygen in the water than the concentration of oxygen in the blood.
What are advantages of countercurrent exchange?
The counter-current exchange system makes
gas exchange extremely efficient
. Fish are able to extract a much higher proportion of oxygen from water than most animals can form air. This is essential for an aquatic lifestyle as water has a much lower oxygen content than air. Water helps to support the gills.
Where is countercurrent exchange found in the body?
Venous blood recovers heat from the arterial blood as the former warms on its way back to the body. Blood vessels in the neck also employ a countercurrent arrangement and that results in a brain temperature about 1°C cooler than that of the body. (A countercurrent exchange of blood oxygen occurs in
the gills of fish
.)
What Animals use countercurrent gas exchange?
Arctic foxes and wolves
– use countercurrent exchange to heat and cool their feet so that they don’t freeze in the ices and snow. Jackrabbits- use this exchange in their ears to help cool their bodies.
Which is better co-current or counter-current?
In Chemical engineering most of the operations are
counter-current
in nature because, the mass transfer or heat transfer will be maximum in the counter-current flow. Co-current flow is preferred in rare cases of heat transfer where a quick heat transfer is required.
Which is better counter flow or parallel flow heat exchanger?
The counter-flow heat exchanger has three significant advantages over the
parallel flow
design. First, the more uniform temperature difference between the two fluids minimizes the thermal stresses throughout the exchanger.
Why is counter-current flow more efficient than co-current flow?
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).
Why does diffusion happen with countercurrent flow?
Counter current involves blood in the capillaries flowing in the opposite direction to the flow of water flowing over them. Gases
diffuse faster from one area to another when the concentration difference between the two areas is at its greatest
, as compared to when the concentration difference is low.
What is counter flowing flowing?
With a counter flow arrangement,
the cooling medium flows in the opposite direction to the liquid being cooled
. Find out why this so much more efficient. In a shell and tube heat exchanger, coolant usually flows through the central ‘tube core’ to cool hot oil, water or air, which passes over and around the tubes.
Is cross flow more efficient or counter flow?
In the mixing zones,
the flow corresponds more or less to the crossflow
, whereas pure counterflow prevails in the middle part. The length of this middle part determines the output first and foremost. This means that it is always possible to achieve the required thermal efficiency of 0.73, but this comes at a price.
What is meant by countercurrent flow?
1 :
flowing in an opposite direction
. 2 : involving flow of materials in opposite directions countercurrent dialysis. Other Words from countercurrent Example Sentences Learn More About countercurrent.
Why is there counter-current flow in dialysis?
The blood flows in one direction and the dialysate flows in the opposite. The counter-current flow of the blood and dialysate
maximizes the concentration gradient of solutes between the blood and dialysate
, which helps to remove more urea and creatinine from the blood.
Why are fish gills rich in blood?
This process of breathing begins when a fish gulps water through its mouth. 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
.
