A 10 mm diameter electrical conductor is covered by an insulation of 2 mm thickness. The conductivity of the insulation is 0.08 W/m-K and the convection coefficient at the insulation surface is 10 W/m2-K. Addition of further insulation of the same material will
increase heat loss to a maximum and then decrease heat loss
Current outer radius is 5+2 = 7 mm. The critical cylindrical radius is k/h = 0.08/10 = 8 mm. Heat loss therefore increases to a maximum and then decreases as insulation is added, for fixed conductor and ambient temperatures.
Important Questions from Critical Thickness of Insulation
Two insulating materials of thermal conductivity K and 2K are available for lagging a pipe carrying a hot fluid. If the radial thickness of each material is the same.
For pipes, the radius of the pipe is taken higher than the critical radius, so that any insulation added will ______.
The insulating ability of an insulator with the presence of moisture would
A steam pipe is to be insulated by 2 insulating materials put over each other. For best results
The critical radius of insulation signifies
