A cylindrical furnace for heat-treating materials in a spacecraft environment has a 90-mm diameter and an overall length of 180 mm. Heating elements in the 135-mm-long section (1) maintain a refractory lining of ?₁ = 0.8 at 800?C. The linings for the bottom (2) and upper (3) sections are made of the same refractory material, but are insulated. Determine the power required to maintain the furnace operating conditions with the surroundings at 23?C.

Transcribed Image Text:

-T- 23°C LA, T, = 800°C E = 0.8 D- 90 mm -L = 135 mm 45 mm