II B.Tech I Semester Supplementary Examinations, November 2005 FURNACE TECHNOLOGY AND PYROMETRY (Metallurgy & Material Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????
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1. (a) Derive an expression for steady state conduction of heat through a composite plane wall.
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(b) A furnace wall is made upof a steel plate of 10mm thickness (k = 15kcal/m − hr − deg). A silica brick layer on inside is laid to 150mm thickness and a magnesia brick of 200mm thickness on outside. The inside and outside wall surfaces are at 650 o C and 125 o C respectively. Calculate heat loss from unit area of wall if KSio2 = 1.75kcal/m−hr−deg and KM go = 4.5kcal/m−hr−deg If heat loss is to be reduced to 2000Kcal/hour by keeping an air gap between steel and magnesia bricks estimate necessary air gap if Kair =0.03 kcal/m − hr − deg . 2. Distinguish between free and forced convection. Define the important dimensionless groups and explain their significance. [16] 3. (a) Give examples of heat exchangers. Develop an expression for heat transfer from one fluid ot another in a
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i. Parallel flow and ii. counter current flow heat exchanger in terms of inlet and outlet temperatures of the fluids and overall heat transfer coefficient.
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(b) A tubular heat exchanger is to be designed for cooling oil from a temperature of 800 c to 300 C by a large body of stagnant water at a constant temperature of 200 C. The heat transfer surface consists of 30m long straight tube of 20mm inside diameter. The oil (cp = 0.6kcal/kg. deg, sp.gr = 0.8) flows through the cylindrical tube with an average velocity of 50cm/sec. Calculate the overall heat transfer coeff. of the oil cooler. [8+8] 4. (a) Define the terms:
i. Black, gray and real surfaces ii. Emissivitly, luminous and non-luminous flames.
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(b) A 2cm thicksteel slab heated to 5250 C is held in air stream of mean temperture 250 C.Calculate the time interval for the slab to reach the temperature 250 C without deviation not more than 0.50 C at any point in the slab. Data given: Density of steel = 7950kg/m3 Cp =455J/kg.deg, k=46w/m.deg, heat transfer coefficient on plate surfce = 36W/m2 .deg. [8+8]
5. What are the characteristic features of vertical shaft furnaces? Draw the profiles of furnaces for melting of iron ores and melting of cast irons. Explain the differences. [16] 1 of 2
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Code No: NR211802
6. (a) Explain Peltier and Thomson emfs. compare and contrast noble and base metal thermocouples. (b) Describe the principles, working and range of temperature measurement of resistance pyrometers. Give typical applications. [8+8]
8. Write short notes on: (a) Planck’s law of monochromatic radiation. (b) Arc furnaces. (c) Sources of heat losses in furnaces
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(d) Thermopile.
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7. State Wien’s law. With a neat sketch explain the functioning principle of any type of optical pyrometer. What factors affect the pyrometer reading and how? [16]
NR211802 II B.Tech I Semester Supplementary Examinations ...
A silica brick layer on inside is laid to 150mm thickness and a · magnesia brick of 200mm thickness on outside. The inside and outside wall · surfaces are at 650 ...
2. Explain the following: · (a) Reynolds number · (b) Nusselt number · (c) log mean temperature differene. (d) importance of heat transfer in furnace technology.
(b) Explain the basic principle of the instrument used for Condition monitoring · of any process. [8+8] · 2. (a) Compare and construct the functioning of rupture ...
What is the theory of lubrication? Explain how surface tension plays a role in the · performance of lubricating oils and hydraulic fluids? What is surface tension ...
(b) What is the purpose of providing âbondsâ in brick work. With the help of · neat sketches illustrate âEnglish bondâ. [8+8] · 2. (a) What is a âdamp-proof courseâ?
(b) The following observations are related to a closed compass traverse ABCD. Find out the stations which suffer local attraction and give the values of the.
NR. (b) Calculate the density of naphthalene decahydride (C10H18) from its refractive index value of 1.4804 at 18 oC. [10+6] · 8. (a) Explain how the depression ...
diagrams. Show that the entropy change during the cycle is zero ... if the small amounts of argon and carbon oxide present in the mixture are · neglected.
(b) Describe various types of heat exchangers based on temperature ... (c) Explain the mechanism of heat transfer by radiation. [5+6+5] ... (a) Thermal diffusivity.
(a) Job order production and batch production system. (b) Mass production and flow production. [4+4+4+4] · 7. DefineâCritical pathâ, âslack timeâand âDummy ...
(b) One bag contains 4 White balls and 3 black balls and a second bag contains 3 ... [8+8] · 3. (a) The amount of bread ( in hundreds of pounds) X that a certain ...
(c) Explain sign conventions of heat and work in thermodynamics. [5+5+6] · 3. (a) State and explain second law of thermodynamics. (b) Define and explain ...
b=4.318 cm is fed by a 4 GHz carrier from a coaxial cable. Determine if a · TE10 mode will be propagated. If so calculate the phase velocity and group · velocity.
(c) An amplifier with voltage gain of 60 decibels uses 0.05 of its output voltage in · negative feedback. Calculate the gain of the feedback amplifier. [6+6+4].
Determine the length of the wire needed if the diameter · of the wire is 0.25 mm. Assuming that the temperature coefficient of resis- · tance of the wire is constant, ...
(b) Draw the block schematic of 4x1 MUX and give its truth table. [6] · 6. (a) Design a full adder with minimum number of NAND gates. [8] · (b) Draw the logic ...
8. (a) Enumerate various mechanical and diffusion properties of cartilage with ex- · amples? [8] · (b) Write briefly about âlubricationâ of joints? [8] · *****. 1 of 1.
Black body and Grey body. iii) · Reynolds number and Nusselts Number. 4.a) Derive Reciprocity theorem when the heat exchange is taking place between the.
Polynomials in single variable are stored in the form of linked lists. Each · structure has space for one coefficient and one exponent and a link. Assume.
armature and field resistances are 0.03 ohm. And 60 ohm ... 6.a) Explain with the help of diagrams how a rotating magnetic field is produced in · the air gap of a ...
(figure.1). (c) Obtain Thevenin's equivalent circuit for the network below figure 2. 1 of 3 ... (a) Obtain open circuit and short circuit parameters. Obtain relation ...
Show the reaction mechanisms of the following reactions. (a) Gatterman reaction. ... How will you determine the configuration of glucose with the help of Fischer's method? 7. (a) What ... Explain the theory of colour and constitution? *****. 1 of 1.
Maximize the following problem using Simplex Method. Z = 10x + y + ... 10; x1, x2 ⥠0. 8. Write short notes on the following: (a) Kuhn-Rucker conditions. 1 of 2 ...
