The chocolate peanut factory

One worldwide-recognised brand in the field of agroindustry manufactures the

industrial chocolate peanut snack W&W's in three steps. Initially, the peanuts are

sieved in order to remove broken grains (B); then, the unbroken peanuts (P) are

driven to the next unit where are first roasted and then covered with chocolate

(C). Following, the third step consists of a crusting operation, where each piece is

covered with a layer of a sugar (S) - water (W) mixture and then is dried. The

scheme below shows the process.

Qkg/h

0.590 kg P/kg

0.410 kg B/kg

Sieving

Qkg Bih

Qkg P/h

Qkg C/h

Roasting

&

Coating

Qkg/h

w.kg C/kg

w kg P/kg

Qkg/h

w.kg Cikg

wkg P/kg

Qkg/h

0.660 kg S/kg

0.340 kg W/kg

Crusting

Qkg W/h

Qkg/h

0.290 kg C/kg

0.430 kg P/kg

0.280 kg S/kg

The stream Qe is made of low quality pieces that cannot be commercialised so it

keeps the same composition as the product sent to crusting unit. In average, there

are 10 kg of satisfactorily coated peanuts per each kg of rejected peanuts. If the

production of commercial W&W's is stated to be 1000.0 kg/h, find the mass

flowrate and compositions of the rest of streams, this is, all feeds (Q₁, Q4 and Q₂)

and exits (Q3, Q6, Qs and Q9). Assume that the process operates in steady state.