A stainless steel billet (k = 13 Btu/hr-ft-F, α = 0.24 ft2 /hr), 4 inches in diameter, is passing through a 20 ft. long heat-treating furnace. The initial billet temperature is 200°F, and it must be raised to a minimum temperature of 1500°F before working. The heat transfer coefficient between the furnace gases and the billet surface is 6 Btu/hr ft2 F, and the furnace gases are at 2200°F. At what maximum velocity (ft/min.) can the billet travel through the furnace and satisfy these conditions?

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.

Consider a large isothermal enclosure that is maintained at a uniform temperature of 2000 k. calculate the emissive power of the radiation that emerges from a small aperture on the enclosure surface. what is the wavelength ? , below which 10% of the emission is concentrated? what is the wavelength ? 2 above which 10% of the emission is concentrated? determine the wavelength at which maximum spectral emissive power occurs. what is the irradiation incident on a small object placed inside the enclosure?