Papers : IFS - Indian Forest Service Chemical Engineering Previous Year Paper (2000)

PAPER - I : SECTION A
1. Answer any four of the following: (10 x 4 = 40)
(a) Develop an expression for predicting the minimum fluidisation velocity.
(b) Explain about the penetration theory of mass transfer.
(c) With a neat sketch, explain the working principle of a spray drier.
(d) Discuss the merits and demerits of different feed conditions in a multiple effect evaporator.
(e) Briefly explain about the effectiveness NTU method for the design of double pipe and shell, and tube heat exchangers.

2. Briefly explain the working principles of the following equipments : (10 x 4 = 40)
(a) Ball mill
(b) Plate-and-frame filter press
(c) Pneumatic conveyor
(d) Rotary pump.

3. Answer the following:
(a) Write on equilibrium and differential distillation. (10)
(b) What do you understand by bound moisture and unbound moisture of a solid material? (10)
(c) Briefly explain about the design of cooling towers. (10)

(d) Define the following:
(i) Absorption factor
(ii) Theoretical number of plates
(iii) Optimum reflux
(iv) Plait point

4. (a) Develop an equation for the radiative heat transfer between two concentric cylinders with diameters d1 and d2 and emissivities e1 and e2 radiating heat at temperatures T1 and T2 K respectively. (20)

(b) Draw a neat sketch of the floating head heat exchanger with one pass on shell side and two passes on tube side and explain the function of its various components. (20)

SECTION B
5. Answer any four of the following: (10 x 4 = 40)
(a) Explain clearly about ion-exchange separation process.
(b) What are the materials generally used in process vessel construction? Briefly explain about the basic characteristics of (i) carbon steels and (ii) high alloy steels.
(c) Mention about various types of supports for (i) vertical vessels and (ii) horizontal vessels. With neat sketches, explain about saddle support and skirt support.
(d) Enlist the different types of pyrometers. Describe the working principle of any one type of pyrometer.
(e) Explain the importance of frequency response study in control system. Define corner frequency and mention its importance.

6. (a) Explain clearly about (i) dialysis, (ii) osmosis and (iii) reverse osmosis. (15)
(b) With neatsketches, explain the working principles of batch dialysis and continuous dialysis and types of equipments used for this purpose. (25)

7. Calculate the cylindrical shell thickness, the conical roof thickness and the thickness of bottom plates for carbon steel (structural) conical roof storage tank to store 250,000 litres of liquid of density 940 kg/m3.
Slope of the roof-one in five.
Superimposed load on the roof= 125 kg/m2.
Permissible stress in steel = 1450 kg/cm2.
Specific gravity of steel = 7.7.
Modulus of elasticity = 2 x 106 kg/cm2
Assume diameter of the tank equal to its height. Draw a free-hand sketch of the tank indicating the essential fittings on it. (40)

8. (a) How do you measure liquid level if (i) the liquid is corrosive and (ii) the liquid contains suspended solid particles? Suggest the instruments to be used in these two cases. Briefly describe their principles of functioning. (20)

(b) Write about the following:
(i) Control valve characteristics (8)
(ii) Block diagram (5)
(iii) PID controllers (7)

PAPER-II : SECTION A
1. Answer any four of the following:
(a) Define theoretical amount of air and excess air supplied for combustion of coal and sulphur. (10)
(b) Define heat of reaction. How do you calculate heat of reaction at a given temperature and pressure? (10)
(c) What are the ideal reactors? Emphasise the assumptions involved in defining the same. (10)
(d) ‘The entropy of the universe is ever increasing’. Discuss. (10)
(e) How do you analyse kinetic data collected in ad experimental batch reactor finally to arrive at the rate equation for the given reaction? (10)

2. A fuel gas containing CO2: 2.1%, C25H42: 7.0%, CO: 33.8%, H2: 40.6%, C12H44: 11.2% and N2: 5.3% is burnt with 30% excess air. Calculate the fuel gas (burner outlet gas) analysis on dry basis. Assume complete combustion in the burner. (40) 3. For the catalytic dehydrogenation of 1-butene (C4H8) to 1,3-butadiene (C4H6) C4H8(g) → C4H6(g) + H2(g) carried out at 900 K and 1 atm, and with a ratio of 10 mol of steam per mol of butene, determine the extent of reaction at equilibrium. Determine the same in absence of the steam too. (40)

4. In an experimental catalytic packed- bed reactor, using a fixed feed rate of FA0 = 10kg- mol/hr, for the reaction A → R, the following kinetic data were collected Find the rate equation. (40)

SECTION B
5. Answer any four of the following:
(a) What are the feed stocks used to produce polystyrene commercially? (10)

(b) What are the major differences in structures and physical properties of low density polyethylene (LDPE), high density polyethylene (HDPE) and linear low density polyethylene (LLDPE)? (10)

(c) What are the permissible limits of the constituents in the ambient air for residential and protected areas in India? (10)
(d) Write short notes on : HAZOP/HAZAN studies (10)
(e) What factors you take into consideration in determining a chemical plant layout? (10)

6. How is paper produced commercially? Describe paper production from the raw materials, with the help of a neat flow sheet. (40)

7. (a) What is ‘greenhouse’ effect? Discuss how various greenhouse gases contribute to the effect. What are your suggestions to minimize the ‘greenhouse’ effect? (24)

(b) How do ground level concentration of pollutant emitted from a chimney vary with meteorological conditions? (16)

8. (a) Define fixed capital and working capital. How do you arrive at them? (20)
(b) Discuss briefly the utility of PERT/CPM charts. (10)
(c) Explain the different components in Profit and Loss Account. (10)