Problem 9.43 The 4 m x 4 m horizontal roof of an uninsulated aluminum melting furnace...
Problem 1: A furnace has a 4 m high composite wall constructed of 4 cm thick fireclay brick on the inside, and 10 cm of oval-core concrete block with sand in the cores as the outer surface. The inside surface of the wall is at 400°C. The outer surface is exposed to quiescent air at 23°C (i.e., natural convection is occurring). What is the steady-state temperature of the outer surface of the wall? Use a film temperature of 400K to...
The hot combustible gasses of a furnace are separated from the ambient air and its surrounding, which are 28oC, by a brick wall 120 mm thick. The brick has a thermal conductivity of 1.23 W/m-oK and a surface emissivity of 0.82. At steady state conditions the outer surface temperature is 120oC. Air surface film conductance is 15 W/m2-oK. What is the total heat transmitted for 20 square meter area.The hot combustible gasses of a furnace are separated from the ambient...
The wall of a furnace consists of two parts, a ceramic brick lining (k=1.1 W/m C,. l=20 mm) and an outer steel wall (k=50 W/ m C, l=10 mm). The inner heat transfer coefficient is 29 W/ m2 C and the outer heat transfer coefficient is 14 W/ m2 C. Taking the bulk temperature of the furnace to be 1000 C and the air temperature outside the furnace as 15 C calculate the temperature of the outer steel wall exposed...
a) what is the heat loss per unit length from the pipe in W/m? b) Estimate the heat loss per unit length if a 50 mm thick layer of insulation with a conductivity of 0.058 W/m K. Neglect radiation for this part. 3. A 0.20-m diameter, thin-walled steel pipe is used to transport saturated steam at a temperature of 486K in a room for which the air temperature is 25°C and convection heat transfer coefficient at the outer surface of...
The surface of a furnace wall is at a temperature of 1350oC. The outside wall temperature is 42oC. The furnace wall is made of 25 cm of refractory material having a thermal conductivity of 1.4 W/moK. The outside wall is steel, 1 cm thick with thermal conductivity of 47 W/moK. Calculate the thickness in meters of brick to be installed in between the refractory material and steel if its thermal conductivity is 0.28 W/moK and the heat loss is not...
The roof of a refrigerated truck compartment is of composite construction, consisting of a layer of foamed urethane insulation (t2 = 50 mm, ki = 0.026 W/mK) sandwiched between aluminum alloy panels t1 = 5 mm, kp = 180 W/m-K). The length and width of the roof are L = 10 m and W = 3.5 m, respectively, and the temperature of the inner surface is Tsi = -10°C. The truck is moving at a speed of V = 105...
A horizontal uninsulated steam pipe passes through a large room whose walls and ambient air are at 300 K. The pipe of 125-mm diameter has an emissivity of 0.85 and an outer surface temperature of 373 K. Calculate the rate of heat loss per unit length from the pipe. The answer should be close to 45.2 W/m Please show all work clearly
Due to a particularly cold day, water that was transported to outdoor equipment through an uninsulated, thin-walled metal pipe began to freeze, which caused a cylindrical ice layer, 4 mm thick, to form on the inside of the pipe. If the pipe is 100 mm diameter with an internal convective coefficient of h = 1400 W/m2- K and a mean water temperature, Tm = 277 K, and the temperature of the inner surface of the ice, Tsi, is 273 K,...
IF YOU CANNOT SOLVE THEM ALL THEN PLEASE DONT SOLVE ANY. A hollow aluminum sphere, with an electrical heater in the center, is used in tests to determine the thermal conductivity of insulating materials. The inner and outer radii of the sphere are 0.15 and 0.18 m, respectively, and testing is done under steady-state conditions with the inner surface of the aluminum maintained at 250°C. In a particular test, a spherical shell of insulation is cast on the outer surface...
The roof of a refrigerated truck compartment consists of a layer of foamed urethane insulation (t2 = 62 mm, ki = 0.026 W/m K) between aluminum alloy panels (t1 = 6 mm, kp = 180 W/m K). The length of the roof is L = 9 m. The net solar radiation into the roof is 131 W/m2. The temperature of the inner surface is Ts,i = -3 °C and the air temperature is T. = 30 °C. The convective heat...