For the aluminum production system described in Figure 10.38, calculate the following.

Question

a. Amount of aluminum input to “primary aluminum casting” (? in kg of aluminum)

b. Amount of aluminum input into “secondary aluminum casting” (?, in kg aluminum)

c. Total energy consumed.

d. If the waste, W, from the product assembly is sent to shape casting to be reused, recalculate all three values for parts (a), (b), and (c).

Answer 1

a. Fraction of material in Product Assembly that becomes waste = 0.08

Therefore the fraction of material in Product Assembly that becomes product is 0.92

If X is mass of material in Product Assembly,

???????????????????????????????? ???????????????? ???????? ???????????????????????????? ???????????????????????????????? ???????????????? ????????????????? ???????????????????????????? = 3.8 ????????

???????????????????????????????? ???????? ???????????????????????????????? ???????? ????????????????? ???????????????????????????? ????????????? ???????????????????????????? ???????????????????? ???????? 0.25

?????????????????????????????????,???????????????????????????????? ????????????? ???????? ???????????????? ???????? ???????????????????????????? ???????????????????????????????? ???????? 0.75

???????????????????????????????? ???????????????????????????????????? ???????? ????????????????? ????????????????????????????

???????????????????????????????? ????????????? ???????????????????????????? ???????????????????? ???????????????? ????????????????? ???????????????????????????? = ???? = 0.25×5.07 = 1.27 ????????

???????????????????????????????? ???????? ???????????????????????????????? ???????? ????????????????? ???????????????????????????? ????????????? ???????????????????? ???????????????? ???????????????????????????? ???????????????????????????? = 0.6

???????????????????????????????? ???????????????? ???????? ????????????????? ???????????????????????????? ???????????????? ???????????????????????????? ???????????????????????????? = 0.6×5.07 = 3.04 ????????

???????????????????????????????? ???????????????? ???????? ????????????????? ???????????????????????????? ???????????????? ???????????????????????????????????? ???????????????????????????? = 0.4×5.07 = 2.03 ????????

???????????????????????????????? ???????????????????????????????????? ???????????????????????????????? ? ????????????? ???????? ???????????????? ???????? ???????????????? = 0.3

?????????????????????????????????,???????????????????????????????? ???????? ???????????????????????????? ???????????????? ???????? ????????????????? ???????????????????????????? = 0.7





d. If the waste W from the Product Assembly is sent to shape casting to be recycled



???????????????????????????????? ???????????????? ???????????????????????????? ???????????????????????????????? ???????????????????????????????? ???????? ????????????????? ???????????????????????????? = 0.08×3.8 = 0.3 ????????



This will change the amount of material needed from Primary and Secondary casting



???????????????????????????????? ???????????????????????? ???????????????? ???????????????????????????? ???????????? ???????????????????????????????????? ???????????????????????????? = 5.07?0.3 = 4.77 ????????



???????????????????????????????? ???????????????? ???????? ????????????????? ???????????????????????????? ???????????????? ???????????????????????????? ???????????????????????????? = 0.6×4.77 = 2.86 ????????







???????????????????????????????? ???????????????? ???????? ????????????????? ???????????????????????????? ???????????????? ???????????????????????????????????? ???????????????????????????? = 0.4×4.77 = 1.91 ????????



???????????????????????????????? ???????????????????????????????????? ???????? ???????????????????????????????????? ???????????????????????????? = ???? +???? = 1.91 ???????? ???? = 1.91????? = 1.91?1.27 = 0.64 ????????