It is designed in such a way that the internal temperature of a commercial heat treatment furnace can reach up to 165 oC. All surfaces of the furnace consist of firebrick (10 cm), insulation material and sheet metal (3mm) from the inside out. Given that the outdoor temperature is 22 oC, the outer sheet will be allowed to go up to 35 oC, which is a temperature that will not disturb in contact with hands. In this case, determine the insulation material thickness to be used. The thermal conductivity coefficient of the insulation material is insulation 0.066 W / m oC, 60 W / m oC for sheet metal and 115 W / m oC for firebrick. Indoor heat transfer coefficient will be accepted as 25 W / m2 oC and 12 W / m2 oC for outdoor environment.

Q: A metal cube of 0.1 m sides is being cooled down uniformly from 300°C to 30°C by placing it in cold…

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Q: A flat wall is exposed to an environmental temperature of 38 oC. The wall is covered with a layer of…

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Q: A furnace wall 200 mm thick is made of a material having thermal conductivity of 1.45 W/m. K. The…

A: Answer: (a) The rate of heat transfer through the wall is 3213.675 Watt. (b) The temperatures on the…

Q: A crucible of molten metal at 1800°C is placed on the foundry floor. The foundry man covers it with…

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Q: 2. A 15 cm diameter aluminum ball is to be heated from 80°C to an average temperature of 200°C.…

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Q: 1. A 1000-W iron is left on the iron board with its base exposed to the air at 20°C. The convection…

A: Heat Transfer

Q: 1. The rate of heat flow (q) through a plane wall of thickness x = 50 mm is 700 watt/m?. Determine…

A: Heat conduction  x = 50 mm = 0.05 m (x = wall thickness) q = 700 W/m2  ( q = Heat transfer per unit…

Q: Heat is generated in a sphere of radius 1 m at a rate of 1000 W/m3. The sphere is surrounded by air…

A: The radius of sphere is The heat generation rate is The temperature of air is The thermal…

Q: On a mild Saturday morning while people are working inside, the furnace keeps the temperature inside…

A: GivenTi=23oCTo=14oCT=19oCτ=3 hrwhen windows are opnedτ=2hr

Q: Two walls of a stol composed of insulating materia (k=0.25 KJ/hr-m-°C) with 15 cm thick and concrete…

A: Given   For insulating material Thermal conductivity, k1 = 0.25 kJ/hr.m.K…

Q: Q1 The inner and outer surfaces a spherical shell with radii of 1 cm and 2 cm are 300°C and 100°C,…

A: We have to find heat transfer through the shell

Q: The walls of the flat furnace are connected by two insulating layers A and B. The temperature of the…

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Q: Two long rods of the same diameter, one of brass(k= 85 W/mK) and the other of copper (k=375 W/mK)…

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Q: A rectangular glass window pane on a house has a width of 1.4 m, a height of 2.2 m, and a thickness…

A: Given:The width of the window is the height of the window is the thickness of the window is the…

Q: A long, thin copper rod 5 mm in diameter is exposed to an environment at 20°C. The base temperature…

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Q: The wall of a refrigerated truck consists of 1.5mm sheet steel outer surface, 10mm plywood at the…

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Q: A window with an Rsrvalue of 0.18 receives 300 W/m² of insolation. If the interior of the building…

A: As given that For window RSI- = 0.18 , insolation = 300 W/m2 ; The temperature of the interior Ti=…

Q: Q2/ An insulated steam pipe having an outside Steam pipe diameter of 30 mm is to be covered with two…

A: Given Thermal conductivity(k1)=5k2 T1 and T2 are fixed Thickness = 20mm=0.02m Outside…

Q: 4.) A 3-m-internal-diameter spherical tank made of 1-cm-thick stainless steel steel is used to store…

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Q: The Resistance (R) of an enclosure of surface area of 8,000sf is 20. What is the amount of heat…

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Q: An element on a hot stove is maintained at a constant temperature of Thot = 105 °C and a pan is…

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Q: 1- The heat flux through a slab made of wood with 50 mm thick, whose inner and outer surface…

A: Given Thickness of block = 50 mm = 0.05 m Internal temperature = 40 oC External temperature = 20 oC…

Q: Q2: A 2.5 -mm-diameter electrical wire is insulated by a 2-mm-thick rubberized sheath (k = 0.11 W/m…

A: In-plane slab, the addition of insulation always reduced the heat loss. But in the case of cylinder…

Radiation

Radiation can be described as the energy in the form of a particular matter or electromagnetic waves traveling in the air and can be in the form of light, sound, and heat. Radiation can be detected through special instruments like X-rays. The radiation from a cooler object is less intense as compared to the radiation from hot objects.