A horizontal steam line carries saturated steam at a rate of 6.0E6 lbm/h. The steam line has a diameter of 2.67 ft, a wall thickness of 2 in, and a length of 150 ft. Accounting for the steam pressure...

A horizontal steam line carries saturated steam at a rate of 6.0E6 lbm/h. The steam line has a diameter of 2.67 ft, a wall thickness of 2 in, and a length of 150 ft. Accounting for the steam pressure drop in the pipe, steam may be considered saturated at an average pressure of 800 psia. The pipe is insulated with a thickness of 7 inches. Find the rate of heat loss to the ambient at 23 C. The emissivity of the insulation is 0.7. Other data include
P_ambient

= 1 atm,
k_s

= 10 Btu/h·ft·F,
k_i

= 0.7 Btu/h·ft·F. The ambient air is quiescent.