ENGINEERING ECONOMY - EXAMPLE 7.2 : In the purchase of a machine with a period n = 8.5 years, the minimum attractive rate of return, i = 12 %, the cost P = $55000, F = $4000 is the salvage, annual maintenance A = $3500. The return of the investment or equivalent uniform annual benefit is $15000. The equivalent uniform annual cost is P (A / P, i, n) + A - F (A / F, i, n). The investment is considered acceptable only when equivalent uniform annual benefit is greater than the equivalent uniform annual cost. From the compound interest table, (A / P, i = 12 %, n = 8 years) = 0.2013, (A / P, i = 12 %, n = 9 years) = 0.1877, (A / F, i = 12 %, n = 8 years) = 0.0813, (A / F, i = 12 %, n = 9 years) = 0.0677. Prove by calculations whether the investment above is acceptable.

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Why reflux is necessary in distillation column?

1 Answers   Deepak Fertilisers,

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could anyone send me model question papers or outline of graduate trainee(chemical engg) post?

0 Answers   NPCIL,

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Where the Induced draft, forced draft & balanced draft furnace are to be used? Selection of furnaces are based on which criteria?

0 Answers   IFFCO, MahaGenco,

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How can one determine if a particular solid can be fluidized as in a fluidized bed?

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What are the assumptions made for kynch theory?

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Name the three classes of organic solvents?

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Question 55 - The differential equation is 3 dy / dt + 2y = 1 with y(0) = 1. (a) The Laplace transformation, L for given terms are : L (dy / dt) = sY(s) - y(0), L(y) = Y(s), L(1) = 1 / s. Use such transformation to find Y(s). (b) The initial value theorem states that : When t approaches 0 for a function of y(t), it is equal to a function of sY(s) when s approaches infinity. Use the initial value theorem as a check to the answer found in part (a).

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Re: Sugar Cane Bagasse What are the 1. Specific Heat of Bagasse at 50% moisture, 40% moisture and 25% moisture? 2. What is bu;lk density of bagasse at 50% moisture, 40% moisture and 25% moisture? 3. What is specific gravity of bagasse at 50% moisture, 40% moisture and 25% moisture? 4. What is the specific heat of flue gases generated from boiler fuelled by bagasse? 5. What is the specific gravity of flue gases generated from boiler fuelled by bagasse?

0 Answers   Voice Engineers,

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Explain the factors involved in considering the choice of dry screw compressor?

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Hi, I am in need of interview questions from Engineers india limited in chemical engineering.if any one has kindly post it to me soon.

0 Answers   Halliburton, IOCL,

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UNIT OPERATION - EXAMPLE 9.2 : A distillation column separates 10000 kg / hr of a mixture containing equal mass of benzene and toluene. The product D recovered from the condenser at the top of the column contains 95 % benzene, and the bottom W from the column contains 96 % toluene. The vapor V entering the condenser from the top of the column is 8000 kg / hr. A portion of the product from the condenser is returned to the column as reflux R, and the rest is withdrawn as the final product D. Assume that V, R, and D are identical in composition since V is condensed completely. Find the ratio of the amount refluxed R to the product withdrawn D. Hint : Solve the simultaneous equations as follow in order to find the answer (R / D) : 10000 = D + W; 10000 (0.5) = D (0.95) + W (0.04); 8000 = R + D.

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