Question

Oranges contain about 15 wt.% solids and 85 wt.% water. In a plant, manufacturing lines A and B are used for the production of orange jam. In the manufacturing line A, crushed orange and sugar are mixed in a 45:55 mass ratio, and the mixture is heated to evaporate water until the residue contains one-third water by mass. (Both line A and B are single units material balances)

(a) Draw and label a flowchart of this process for line A separately.                                                 (5)

(b) Calculate how many pounds of oranges are needed to make a pound of jam.                          (5)

(c) Making a pound of jam is something you could accomplish in your own kitchen (or maybe even a dorm room). However, a typical manufacturing line for jam might produce 1500 lb_m/h. List technical and economic factors you would have to take into account as you scaled up this process from your kitchen to a commercial operation.                                                                                                                  (6)

(d) In the manufacturing line B, the velocity of the orange jam stream containing about 15 wt% solids and 85 wt% water was measured to be 10.5 m/s and the radius of the piping was 8 inches. Line B has the same mixing mass ratio as line A.

e) Calculate the mass flow rate of the orange jam product.                                                              (10)

f) Calculate the number of oranges per year that can be processed with this process if it is run 8 hours a day and 360 days a year. Ignore changes due to unsteady state at startup. Use the following data: Mass of an orange: 0.4 kg Water content of an orange: 85% Density of the solids: Since its mostly sugars, it’s about the density of glucose, which is 1.540g/cm³                                         (6)

Answer 1

Answering the first 4 questions by applying material balances as shown.

c). Technical and economic factors considered while scaling up jam production process from kitchen to commercial operations are :

i). In kitchen, we can use a simple juicer to extract orange juice and then in a single pan over flame after adding sugar (and stirring with a spoon) we can heat it to get the required jam

If we are producing it commercially, a crusher needs to be installed for orange juice extraction, a mixer for achieving a uniform mixing of sugar in solution. Then an evaporator for concentration to achieve the desired jam.

ii) For a continuous operation in commercial production, a proper network of pipe streams is laid for the transportation within the equipments.

iii). In commercial production, instrumentation is required in plant for the various parameters control in process and a QCD lab needs to be set up to analyse the concentrations etc. because during commercial production, product specifications are to be maintained constant.

iv). Requirements for plant utilities like electricity, steam, instrument air etc. during commercial production.