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A countercurrent mechanism system is a mechanism that expends energy to create a concentration gradient. It is found widely in nature and especially in mammalian organs. For example, it can refer to the process that is underlying the process of urine concentration, that is, the production of hyperosmotic urine by the mammalian kidney .
Initially the countercurrent exchange mechanism and its properties were proposed in 1951 by professor Werner Kuhn and two of his former students who called the mechanism found in the loop of Henle in mammalian kidneys a Countercurrent multiplier [14] and confirmed by laboratory findings in 1958 by Professor Carl W. Gottschalk. [15]
The number of transfer units (NTU) method is used to calculate the rate of heat transfer in heat exchangers (especially parallel flow, counter current, and cross-flow exchangers) when there is insufficient information to calculate the log mean temperature difference (LMTD). Alternatively, this method is useful for determining the expected heat ...
In other words, the length of the loop of Henle limits the concentration of the gradient, i.e., the longer the loop, the greater the osmotic gradient. Thus, longer loops would allow for steeper gradients and greater capacity to concentrate urine. Through the countercurrent multiplier the loop of Henle increases the osmolarity of the medulla.
A regenerative heat exchanger, or more commonly a regenerator, is a type of heat exchanger where heat from the hot fluid is intermittently stored in a thermal storage medium before it is transferred to the cold fluid. To accomplish this the hot fluid is brought into contact with the heat storage medium, then the fluid is displaced with the cold ...
A fixed disk allows the two phases to be mixed and to create an emulsion. It operates as a pump to draw the two phases from the preceding stage. Decantation chamber where the two previously mixed liquids are thoroughly separated by centrifugal force. Overflow weirs stabilize the separation area independently of flow rates.
For large scale productions and for very valuable molecules countercurrent solid movement need to be applied to increase the separation efficiency, the yield and the productivity of the purification. The MCSGP process combines both techniques in one process, the countercurrent SMB principle and the solvent gradient batch technique.
Countercurrent distribution, therefore, is a method of using a series of vessels (separatory funnels) to separate compounds by a sequence of liquid-liquid extraction operations. Contrary to liquid-liquid extraction, in the CCD instruments the upper phase is decanted from the lower phase once the phases have settled.