Countercurrent and concurrent exchanger?

[scilearner]

Hello everyone,

 

I searched the net but I don't understand the difference.

 

BLO0D FLOW ---------------------------------->

0% ........................................… saturation

0% ........................................… saturation

WATER FLOW <-------------------------------

 

Countercurrent

 

BLO0D FLOW ---------------------------------->

0% ........................................… saturation

100%..................................… saturation

WATER FLOW --------------------------------->

 

Concurrent

 

I understand how equilibrium would be reached in concurrent but I don't understand how counter current maintains a concentration gradient. Please explain in simple language. Also if you can explain the above diagrams, I got it from net I don't understand them much. Thanks

Edited November 2, 2010 by scilearner

[scilearner]

Hello guys I just want to know why is that when 2 flows are parallel and opposite to each other, a concentration gradient is maintained always.