Question 49 - According to rules of thumb in chemical process design, consider the use of an expander for reducing the pressure of a gas when more than 20 horsepowers can be recovered. The theoretical adiabatic horsepower (THp) for expanding a gas could be estimated from the equation : THp = Q [ Ti / (8130a) ] [ 1 - (Po / Pi) ^ a ] where 3 ^ 3 is 3 power 3 or 27, Q is volumetric flowrate in standard cubic feet per minute, Ti is inlet temperature in degree Rankine, a = (k - 1) / k where k = Cp / Cv, Po and Pi are reference and systemic pressures respectively. (a) Assume Cp / Cv = 1.4, Po = 14.7 psia, (temperature in degree Rankine) = [ (temperature in degree Celsius) + 273.15 ] (9 / 5), nitrogen gas at Pi = 90 psia and 25 degree Celsius flowing at Q = 230 standard cubic feet per minute is to be vented to the atmosphere. According to rules of thumb, should an expander or a valve be used? (b) Find the outlet temperature To by using the equation To = Ti (Po / Pi) ^ a.

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Why LMTD is calculated in Heat -Exchanger problems..Why dont we take average temperature??

4 Answers   Aker Solutions,

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could any one plzz give me the placement tech papers taken by iocl,and bpcl in chemical stream..... my id is.... mishra.gaurang@gmail.com

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What is a good estimate for the absolute roughness for epoxy lined carbon steel pipe?

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DIFFERENTIAL EQUATIONS - EXAMPLE 20.3 : A differential equation is given as y” + 5y’ + 6y = 0, y(0) = 2 and y’(0) = 3. By using Laplace transform, an engineer has correctly produced the equation L {y} = (2s + 13) / [(s + 2)(s + 3)] = A / (s + 2) + B (s + 3). (a) Find the values of A and B. (b) The inversed Laplace transform of 1 / (s + a) is given by exp (-at) where a is a constant. If the statement : L {y} = 9 L { exp (-2t) } - 7 L { exp (-3t) } is correct, find the equation of y as a function of t as a solution to the differential equation stated in the beginning of this question. When L {d} = 9 L {b} - 7 L {c}, then d = 9b - 7c with b, c and d are unknowns.

1 Answers  

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Please help to get IOCL/HPCL or other chemical engineering paper pls send kathir_skv@yahoo.com Regards, kathirvel

0 Answers   Essar,

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Explain the Deacon reaction?

2 Answers  

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What is the Import Procurement Cycle ? and what are the customization steps in SAP ?

0 Answers   Siemens,

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what is zeroth law ?

6 Answers   ISRO,

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what is Vx-EHT(RED) complex chemical compound.

1 Answers   Excel,

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CHEMICAL ENERGY BALANCE - EXAMPLE 11.1 : Please match the term A - E with the stated definition i - v. Terms : A. Yield. B. Selectivity. C. Relative saturation. D. Molal saturation. E. Absolute saturation. Definitions : i. (moles of desired product formed) / (moles that would have been formed if there were no side reactions and the limiting reactant has reacted completely); ii. (moles of desired product formed) / (moles of undesired product formed); iii. (relative humidity 40 % means partial pressure of water vapour equals 4 / 10 of the vapour pressure of water at the system temperature); iv. (moles of vapour) / (moles of vapour dry gas); v. (mass of vapour) / (mass of dry gas).

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Hi this is aparna.............can any one send drdo question papers on my email id-aparna_patna08@yahoo.com Thanks in advance

2 Answers   DRDO,

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