Mass Balance: Homework Problems
Q1) In a snack frying process, potato chips are being produced at a rate of 1000 kg/h. The chips contain 35 % oil. The frying process is using up 375 kg/h of oil. Assume that the level of oil in the fryer in constant. How much oil is leaking from the fryer, if any?
If the potato dough entering the process contains 40 % moisture and the final chips contain 2% moisture, 2% salt and 3% emulsifier, how much water is being boiled off during frying? If the dough is made from potato flour containing 10 % water, how much flour is being used? How much emulsifier and salt are being used? Assume that salt and emulsifier are added to the dough.
Q2) In the glucose recycle problem solved in class,
A. Calculate using Excel and plot sizes of purge (P) and recycle (R) streams as a function of fructose yield (F) for 10% impurity in the incoming glucose stream (G).
B. Also, following the procedure that I went over in the class for P=0, show the first three steps of calculations showing how the values of F, I, an R evolve over time, for P=20 kg.
C. Consider a case when P = R (splitter). Calculate and plot the values of P, x, F as a function of impurity I (vary between 1% to 10%).
Problem on Unsteady State Mass Balance
Q3) A large tank of volume 10 m3 contains salt solution. The tank is half full and the concentration of salt in the tank is 500 grams per liter. In order to dilute the concentration of salt, fresh water is introduced in the tank at a rate of 50 liters/min. How long will it take to achieve the desired final concentration of 50 grams of salt per liter? Assume 1) the tank is well mixed 2) it is OK if it overflows.
Plot the concentration of salt in the tank and amount of salt in the tank as function of time.
4) In the sugar purification problem involving a centrifuge, that was solved in the class, calculate and plot the purity of sugar coming out of the dryer as a function of centrifuge efficiency. In the problem that was solved in class, the centrifuge efficiency was 80%. Take several values for the efficiency.
Attachment:- Assignment.rar