السلام عليكم ورحمة الله وبركاته
السؤال هو التالي:
[LEFT]Fresh organic juice contains 12% by mass of solids, besides the balance water, and concentrated organic juice contains 42% by mass solids. Initially a single evaporation process was used for the concentration, but volatile constituents of the juice escaped with the water, leaving the concentrate with flat taste. The current process overcomes this problem by bypassing the evaporator with a fraction of the fresh juice. The juice that enters the evapotator is concentrated to 58%
(by mass). And the evaporator product stream is mixed with the bypassed fresh juice to achieve the desired final concentration.
a) Draw and label a flowchart of this process, neglecting the vaporization of everything in the juice but water. First prove that the subsystem containing the point where the bypass stream splits off from the evaporator feed has one degree of freedom. Then perform the degree-of-freedom analysis for all subsystems. And then write (in order) the equations you would solve to determine all unknown stream variables.
b) Calculate the amount of product (42% by mass concentrate) produced per 100 kg fresh juice fed to the process and the
fraction of the feed that bypass the evaporator.