QP-IFSM-24-CHEMICAL-ENGINEERING-PAPER-I-021224

Indian ie oa (Nan) JBNV-U-CHME CHEMICAL ENGINEERING Paper -I Time Allowed : Three Hours Maximum Marks : 200 Question Paper Specific Instructions Please read each of the following instructions carefully before attempting questions : There are EIGHT questions in all, out of which FIVE are to be attempted. Questions no. 1 and 5 are compulsory. Out of the remaining SIX questions, THREE are to be attempted selecting at least ONE question from each of the two Sections A and B. Attempts of questions shall be counted in sequential order. Unless struck off, attempt of a question shall be counted even if attempted partly. Any page or portion of the page left blank in the Question-cum-Answer Booklet must be clearly struck off: All questions carry equal marks. The number of marks carried by a question/part is indicated against it. Unless otherwise mentioned, symbols and notations have their usual standard meanings. Assume suitable data, if necessary, and indicate the same clearly. Neat sketches may be drawn, wherever required. Answers must be written in ENGLISH only. JBNV-U-CHME 1 Ql. (a) (b) (c) (d) (e) Q2. (a) (b) (ce) SECTION A Briefly describe the working principle of a steam jet ejector, along with its performance. Discuss the dependency of temperature on the viscosities of gases and liquids. Describe various types of dryers with sketches and applications. In liquid-liquid extraction, describe the selection criteria of good solvents. A grey body of 20 m2 area, radiates 106 W at 1227°C. Calculate the emissivity of grey body. If the temperature is increased to 1327°C, what would be the percentage change in emissive power ? Countercurrent stripping of ammonia from a dilute solution by air is carried out in a sieve tray column having 6 trays. The equilibrium relationship is given by y, = 0-85 x,. 90 percent of ammonia is removed when the molar flow of air is 1-5 times that of the solution. (i) Calculate the ideal stages of the column and stage efficiency. (ii) | Find the percentage removal, if the air rate of flow is increased to 2 times the solution rate. Rivers are the source of water supply for factories. Water at the rate of 2 x 10° kg/hr has to be pumped from a river to a factory overhead tank, placed at a height of 25 metres from the river bed, the total length of pipeline being 1500 metres. The iron pipe having an inside diameter of 30 cm has been used for this pumping. The viscosity of river water is 0-764 cP and friction factor is given by f = 0-0014 + a] . Calculate : (i) The Reynolds number (Re), if p = 1 gm/cc (ii) The head loss due to friction. The wall of a furnace is constructed from an inner layer of 0-6 cm thick steel (k = 40 W/mK) and an outer layer of 10 cm brick (k = 2-5 W/mK). The inner surface temperature is 900 K and the outside surface temperature is 480 K. Calculate the heat loss from the furnace per unit area and also the temperature at the interface. Assume steady state exists and effects at the corners and edges of the wall are negligible. The temperatures at the surface are uniform. JBNV-U-CHME 2 15 15 10 Q3. (a) (b) (c) A hot moving body is 0-62 m long, 0-2 m wide and 0-1 m deep. The surface temperature of the hot body is 350 K. Find the rate of heat flow (heat loss) from the hot body to the atmosphere at 276 K at a speed of 29 m/s. The conditions are such that boundary layer may be assumed turbulent over the entire surface. The radiation from the hot body may be neglected. The same average convection heat transfer coefficient, as for the bottom and sides, may be used for the front and rear surfaces. The properties of air at the average temperature are given as : Density = 1-092 kg/m; Viscosity = 19-123x10-6 N.s/m?2. Thermal conductivity = 0-0265 W/m.K, Specific heat = 1014 J/kg.K, Prandtl Number = 0-71. k 0-62 m > oe Air ae 02m 29 m/s was Bottom of the moving body, 350 K Crushing is an important method for size reduction of solid particles. Estimate the energy required to crush 1 x 10° kg/hr of sodium silicate, if 80% of the feed passes through a screen 3-75 cm aperture and 80% of the product passes through a screen with 0-03 cm aperture. The work index (Wj) for sodium silicate is 13-1. A spherical naphthalene ball of 10 gm is kept suspended in a large volume of air at 45°C and one atm pressure. Diffusivity of naphthalene in air Dap=6-92 x 10-6 m*/s, and density p=1-14 gm/cc. The sublimation pressure at 45°C is 0-8654 mmHg. Calculate the time required for sublimation of 7 gm of naphthalene. Molecular weight of naphthalene is 128. JBNV-U-CHME 3 15 15 10 A 20% NaOH solution is concentrated in an evaporator. 4500 kg/h of this solution enters the evaporator at 333 K and the product contains 50% solids. The pressure of saturated steam used is 172-4 kPa and the pressure in the vapour space of evaporator is 11-7 kPa. The overall heat transfer coefficient is 1565 W/m? K. Calculate the heating surface area required and the steam economy of the evaporator. The heat capacity of superheated steam may be taken as 1-884 kJ/kg.K. 15 The required charts and steam tables are enclosed. ) ಟ೦11೧[೧೪ ૩1૦૩4૫ 181005 Jo 151੦੪ 601୦ | (3, eprxoipAy 07608 Jo ٢0070۰ snoonbe এ0} மர 801707౧౧ : 1 "গান (4) 13174 مز‎ 1810 பத (a) 051 901 04 ९) 0 - હ! க்‌, | | 71% ଥି r ஜு 2 4 গর গলপ काकाको aden : ગ 9५ ++ PP HOTN జ १२02 ٦ ന 4 > ५ 7ا‎ + ॐ । ೫1 لف‎ ८) ૮ 1 8 . 4- ¦ 7 17 + 001 > নল | ‹ A : 4 क ਫ਼. 001 ਤਰ 1 | 24 ந்‌ A 1 : € ட்ட ৷ 4 iN 20 ૧-1 ந்த்‌ ഹട ‰ १५०४ ~ ८1-11-11 14 11८4 7 HON % 305 லி ୨154 kt कि കാ % १० ৰ லர দা 7 09 i 1 † fs ల్లో “੧-1 ੧ ಇ હાડ ડાઇ এ. 1 001 $८ os ೪2 9 04 ق2011 39190 مر 2243 (9১)‏ JBNV-U-CHME # | 87/7 4680) ] 0 6 {) 0.20 0.30 0.40 0.50 0.10 (૫૦1૩0૦૬ யுவ ۸7 ¦ ¦ Concentration (wt fraction 11) JBNV-U-CHME Enthalpy concentration chart for the system NaOH-water FIGURE 2 Table 1 : Properties of saturated Steam and Water (Steam Table), SI Units e — — Volume Enthalpy ie ‘ a =i Diceniie (m*/kg) (kJ/kg) - (kPa) Liquid Sat’d Vapour Liquid Sat’d Vapour Liquid Sat’d Vapour 0.01 0.6113 0.0010002 206.136 0.00 2501.4 0.0000 9.1562 3 0.7577 0.0010001 168.132 12.57 2506.9 0.0457 9.0773 6 0.9349 0.0010001 137.734 25.20 2512.4 0.0912 9.0003 9 1.1477 0.0010003 113.386 37.80 2517.9 0.1362 8.9253 12 1.4022 0.0010005 93.784 50.41 2523.4 0.1806 8.8524 15 1.7051 0.0010009 77.926 62.99 2528.9 0.2245 8.7814 18 2.0640 0.0010014 65.038 75.58 2534.4 0.2679 8.7123 21 2.487 0.0010020 54.514 88.14 2539.9 0.3109 8.6450 24 2.985 0.0010027 45.883 100.70 2545.4 0.3534 8.5794 25 3.169 0.0010029 43.360 104.89 2547.2 0.3674 8.5580 27 3.567 0.0010035 38.774 113.25 2550.8 0.3954 8.5156 30 4.246 0.0010043 32.894 125.79 2556.3 0.4369 8.4533 33 5.034 0.0010053 28.011 138.33 2561.7 0.4781 8.3927 36 5.947 0.0010063 23.940 150.86 2567.1 0.5188 8.3336 40 7.384 0.0010078 19.523 167.57 2574.3 0.5725 8.2570 45 9.593 0.0010099 15.258 188.45 2583.2 0.6387 8.1648 50 12.349 0.0010121 12.032 209.33 2592.1 0.7038 8.0763 55 15.758 0.0010146 9.568 230.23 2600.9 0.7679 7.9913 60 19.940 0.0010172 7.671 251.13 2609.6 0.8312 7.9096 65 25.03 0.0010199 6.197 272.06 2618.3 0.8935 7.8310 70 31.19 0.0010228 5.042 292.98 2626.8 0.9549 7.7553 75 38.58 0.0010259 4.131 313.93 2635.3 1.0155 7.6824 80 47.39 0.0010291 3.407 334.91 2643.7 1.0753 7.6122 85 57.83 0.0010325 2.828 355.90 2651.9 1.1343 7.5445 90 70.14 0.0010360 2.361 376.92 2660.1 1.1925 TAT91 95 84.55 0.0010397 1.9819 397.96 2668.1 1.2500 7.4159 100 101.35 0.0010435 1.6729 419.04 2676.1 1.3069 7.3549 JBNV-U-CHME 6 Vapour — Volume Enthalpy pees . — Preseave (m*/kg) (kJ/kg) (kPa) Liquid Sat’d Vapour Liquid Sat’d Vapour Liquid Sat’d Vapour 105 120.82 0.0010475 1.4194 440.15 2683.8 1.3630 7.2958 110 143.27 0.0010516 1.2102 461.30 2691.5 1.4185 7.2387 115 169.06 0.0010559 1.0366 482.48 2699.0 1.4734 7.1833 120 198.53 0.0010603 0.8919 503.71 2706.3 1.5276 7.1296 125 232.1 0.0010649 0.7706 524.99 2713.5 1.5813 7.0775 130 270.1 0.0010697 0.6685 546.31 2720.5 1.6344 7.0269 135 313.0 0.0010746 0.5822 567.69 2727.3 1.6870 6.9777 140 316.3 0.0010797 0.5089 589.13 2733.9 1.7391 6.9299 145 415.4 0.0010850 0.4463 610.63 2740.3 1.7907 6.8833 150 475.8 0.0010905 0.3928 632.20 2746.5 1.8418 6.8379 155 543.1 0.0010961 0.3468 653.84 2752.4 1.8925 6.7935 160 617.8 0.0011020 0.3071 675.55 2758.1 1.9427 6.7502 165 700.5 0.0011080 0.2727 697.34 2763.5 1.9925 6.7078 170. 791.7 0.0011143 0.2428 719.21 2768.7 2.0419 6.6663 175 892.0 0.0011207 0.2168 741.17 2773.6 2.0909 6.6256 180 1002.1 0.0011274 0.19405 763.22 2778.2 2.1396 6.5857 190 1254.4 0.0011414 0.15654 807.62 2786.4 2.2359 6.5079 200 1553.8 0.0011565 0.12736 852.45 2793.2 2.3309 6.4323 225 2548 0.0011992 0.07849 966.78 2803.3 2.5639 6.2503 250 3973 0.0012512 0.05013 1085.36 2801.5 2.7927 6.0730 275 5942 0.0013168 0.03279 1210.07 2785.0 3.0208 5.8938 300 8581 0.0010436 0.02167 1344.0 2749.0 3.2534 5.7045 JBNV-U-CHME Table 2 : Properties of Superheated Steam (Steam Table), SI Units (v, specific ____ volume, m*/kg; 77, enthalpy, kJ/kg; 5, entropy, ... m°/kg; 7, enthalpy, kJ/kg; s, entropy, kJ/kg.K) Absolute Temperature (°C) Pressure kPa 100 150 200 250 300 360 420 500 (Sat. Temp., __ © ‎ 17.196 19.512 21825 24,186 26445 29.216 31.986 35.679 10 26875 2783.0 2879.55 29773 80765 31976 3320.9 3489.1 (45.81) 84479 8.6882 8.9038 9.1002 9.2813 9.4821 9.6682 9.8978 3418 3.889 4856 4.820 5.284 5.839 6.394 7.134 50 H 26895 2780.1 28777 297.0 8075.5 3196.8 20.4 3488.7 (81.33) 7.6947 7.9401 8.1580 8.3556 8.5873 8.7385 8.9249 9.1546 2.270 2587 2900 3211 3.520 3.891 4.262 4.755 75 H 26794 2778.2 28765 2975.2 80749 3196.4 3320.0 3488.4 (91.78) 7.5009 7.7496 7.9690 8.1673 8.3498 8.5508 8.7374 8.9672 12 1.6958 1.9364 2.172 2.406 2.639 2.917 8.195 8.565 100 26722 27764 2875.3 29743 3074.8 3195.9 8819.6 3488.1 (99.63) 7.3614 76134 7.8343 8.0883 58 8.4175 .6042 8.9342 1.2853 1.4443 1.6012 1.7570 1.9482 2.129 2.376 150 H 2772.6 28729 2972.7 8073.1 3195.0 83189 3487.6 (111.37) s 7.4193 7.6488 7.8488 80790 8.2293 84168 8.6466 1? 0.4708 0.5842 0.5951 0.6548 0.7257 0.7960 0.8898 400 H 2752.8 2860.5 20642 3066.8 81908 88153 3484.9 (143.63) 8 6.9299 7.1706 7.8789 /7.5662 7.712 7.9598 8.1918 1? 0.2999 0.8363 0.8714 0.4126 ` 0.4533 0.5070 700 77 28448 2953.6 ଓ୦୫୨.1 3184.7 33109 3481.7 (164.97) 5 6.8865 7.1088 7.2979 7.5063 7.6968 7.9299 y 0.2060 0.2327 _0.2579 0.2873 ` 0.3162 0.8541 1000 2827.9 29426 30612 3178.9 3065 3478.5 (179.91) 6.6940 69247 9 7.3349 75275 7.7622 1? 0.18248 0.15195 .16966 .18988 0.2095 0.2852 1500 27968 29233 3037.6 3.1692 8299.1 3473.1 (198.32) s 6.4546 6.7090 6.9179 7.1363 7.8828 7.5698 0.11144 118547 0.14113 0.15616 0.17568 2000 2902.5 3023.5 3159.3 3291.6 3467.6 (212.42) 8 6.5453 6.7664 6.9917 71915 7.4817 1? 0.08700 0.09890 0.11186 0.12414 0.13998 2500 2880.1 3008.8 3149.1 8284.0 3462.1 (223.99) 5 6.4085 8 6.8767 88 7.8234 1? 0.07058 0.03114 0.09933 019879 0.11619 3000 2855.8 29985 3188.7 3276.3 3456.5 (23890 2 6272 6 60 69% ? __ 6.5890 6.7801 6.9878 7.2338 JBNV-U-CHME 8 (b) | Write explanatory notes on the following : 5x2=10 (i) Minimum fluidization velocity (ii) Navier-Stokes equation (c) An oil is being cooled in a heat exchanger from 372 K to 350 K and flows inside the tube at a rate of 3600 kg/h. A flow of 1450 kg water per hour enters at 289K for cooling and flows outside the tube. Mean heat capacity of the oil, Com = 230 kJ/kg.K and for water, Com = 4187 kJ/kg K. @ Calculate the outlet temperature of water and heat transfer area if the overall heat transfer coefficient U; = 340 W/m2.K and the streams are countercurrent. (ii) | Find the above two values for parallel flow streams as mentioned in part (i). 15 JBNV-U-CHME 9 Q5. (a) (b) (c) (d) (e) SECTION B Find the solution to the following Laplace equation : s F(s) = ———-——_ ‘s) (s+1)(s+4) What do you understand by the term “steady state temperature” ? Steady state temperature of a thermometer (time constant 0-2 min) is 30°C. At time t = 0, the thermometer is placed in a bath maintained at 40°C. What will be the temperature read by the thermometer after 9-0 seconds ? What are the types of heads used for vertical tall vessels ? Explain each type with neat diagram. Explain the applications of supercritical fluid in separation processes. Explain mechanism of separation by dialysis with a neat concentration profile diagram. Two tanks are connected in series (non-interacting mode) as shown in the figure. The time constants are t, = 1 and t, = 0-5; Ry = 1. Plot the response of the level in tank 2 if a unit-step change is made in the inlet flow rate to tank 1. (Graph paper is enclosed) A q(t) | ‘a JBNV-U-CHME 10 10 Qi. (b) (c) (a) (b) (c) It is proposed to remove Cat? from water which contains 0-15 gm/litre by using Na-resin. The percentage removal of Cat ions is to be 90%. The resin has ion exchange capacity of 3 eq/litre. Find out the quantity of resin needed to remove Cat2 ion of 40,000 litres water. Selectivity is given as K’o,/K’y, = 2-5. Explain the following with neat sketch : (i) Ultimate stress (ii) Proof stress (iii) Yield stress (iv) Resilience A vessel is to be designed for maximum operating pressure of 450 kN/m2. The vessel has a nominal diameter of 1-4 m and tangent to tangent length 2-5 m. The maximum allowable design stress of the material is 120 MN/m? at working temperature. Corrosion allowance is 1-5 mm. The weld joint efficiency of vessel material is 0-80. Calculate the thickness of standard plate to fabricate this vessel. Define the term “Final value theorem”. Also find an analytical expression for n unit impulse response of a system whose transfer function is given by Ye)___28 X(s) (5? +35 +2) In an industrial township it is required to supply drinking water of 2 x 107 litres/day from raw water containing 3-3% salt concentration. It is decided to use RO unit, so that it can supply drinking water with < 300 ppm of salt. Membrane used was of thickness 0-8 micrometer and having water permeability of 70 L/m2.h MPa and salt rejection 98%. The pressure applied in feed side is 75 atm and on the permeate side is 1-0 atm. Assume polarization modulus is 1-2. Calculate area of membrane needed if only 30% of the feed water permeates through the membrane. JBNV-U-CHME 11 15 15 15 10 15 Q8. (a) Explain the general categories of chemical attacks for handling corrosive liquids in vessel. For handling and storage of 98% sulphuric acid and phosphoric acid, what materials do you recommend for storage economically ? (b) An organic solution in 0-05 molar NaCl needs to be separated by ultrafiltration. The filtration is gel layer controlled. The feed concentration is 0.01 gm/mL and gel concentration is 0.4 gm/mL. The charge number of organic molecule is 10e and radius 0-005 micrometer. Calculate the permeate flux. Data : Mass transfer coefficient 5 x 10-5 m/s. (c) Express the transfer function (C/R), for the following block diagram. an eee Ro ee Be M| JG, v JBNV-U-CHME 12 15 10 15