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A schedule number 40 standard steel pipe (outer diameter 4.5 in. and wall thickness 0.237 in.) carrying steam is lagged (insulated) with two layers. First layer (near the steel pipe) having 50mm thickness is made of 85% magnesia and second layer having 60 mm thickness is made of cork. The inner surface temperature of the steel pipe is maintained at 150°C and the outer surface temperature of the cork is maintained at 35°C. Determine the individual thermal resistance of each layer and the rate of heat loss per meter length of the pipe. Consider only the conduction heat transfer. Make suitable assumptions if necessary? (Take
1 in.= 2.54 cm)
Material: Thermal.conduct.
Steel pipe. 45(W/(m-°C)
85% magnesia. 0.07 "
Cork 0.043 "
A metal ball (radius 2.5 cm) initially at a uniform temperature of 450°C is suddenly placed in a controlled environment in which the temperature is maintained at 100°C. The convective heat transfer coefficient is 10 W/(m² -K). Determine the time taken (in hours) for the metal ball to cool to 150 °C ? Clearly mention the suitable assumptions if necessary?. Property data are given below.
Property of all metal ball,unit ___________ value
Density, kg/m³_______7800
Thermal conductivity,W(m-°C)____35
Heat capacity, (J/kg-°C) 460
A light fuel oil is used in the tube side of a 2-4 shell-and-tube heat exchanger. Water is heated in the shell side from 10°C to 50°C while the oil is cooled from 90°C to 60°C. The overall heat-transfer coefficient is 53 W/(m²-°C). The LMTD correction factor is 0.975.
Calculate the area of the heat exchanger for a total heat transfer rate of 500 kW. ?
Draw the temperature profiles of hot and cold fluids in a 1-2 shell and tube heat exchanger?
Draw the neat sketch of a 1-2 shell and tube heat exchanger?
Determine all the view factor for a duct of equilateral triangular cross section. Assume that all surfaces are plane.?
A chamber for heat curing large aluminium sheets, lacquered black on both sides, operates by passing the sheets vertically between two steel plates 150mm apart. One of the steel plates is at 300°C and the other plate is at 25°C. The emissivity of steel plates is 0.56 and the Stefan-Boltzmann constant is 5.67x108 W/(m²-K4). What is the heat transfer rate per unit area between the plates?
Write short notes on pool boiling of saturated liquid with neat sketch of flux vs temperature drop?
Derive the equation for the partial pressure distribution of A and B for diffusion of A through non-diffusion B considering the point z-0 to z-z where the partial pressure of A is PA?
A Test tube, 1.5 Cm in diameter and 12cm long, has 0.4g camphor on it. How long will it take for the camphor (C,H,O) does disappear? The pressure is atmospheric and the temperature is 200C. The sublimation pressure of camphor at this temperature is 97.5 mmHg and the diffusivity of camphor can be estimated by using the fuller' equation. Diffusion volumes: C-16.4, H=1.98, O-5.48, Air 20.1?
