Liquid nitrogen is stored in a spherical tank of 1-m diameter, where tank surface is maint...

Liquid nitrogen is stored in a spherical tank of 1-m diameter, where tank surface is maintained uniformly at 80 K. The spherical tank is enclosed by a 1.6-m diameter concentric sphere with uniform surface temperature of 273 K. Both spherical surfaces have an emissivity of 0.01, and the gap between the inner sphere and outer sphere is vacuumed. Determine the rate of vaporization for the liquid nitrogen.