Steam at 200ºC flows in a cast iron pipe (k = 80 W/m•ºC) whose inner and outer diameters are D1 = 0.20 m and D2 = 0.22 m. The pipe is exposed to room air at 35ºC. The heat transfer coefficients at the inner and outer surfaces of the pipe are 90 and 20 W/m2•ºC, respectively. The pipe is to be covered with glass wool insulation (k = 0.05 W/m•ºC) to decrease the heat loss from the steam by 90 percent. The required thickness of the insulation is
(a) 1.2 cm
(b) 2.0 cm
(c) 2.8 cm
(d) 3.3 cm
(e) 4.0 cm
We need at least 10 more requests to produce the solution.
0 / 10 have requested this problem solution
The more requests, the faster the answer.