Vacuum Furnace Insulation

Vacuum Furnace Insulation Two types of insulation are used in vacuum furnaces: the radiation shield and a hot pack of solid or fibrous insulation.

In the radiation shield, each time a vacuum space is provided between two adjacent parallel sheets of matter, the heat loss is reduced. Heat can transfer between the two only by radiation. The amount of heat transferred depends primarily on the temperature difference between them, and also on their surface quality. Usually, the hot face and one or more inner shields are a refractory metal, or graphite for the highest temperatures, and the remaining shields are of a less expensive material, such as stainless steel. The hot pack insulation uses various combinations of metal and graphite or conventional insulating fiberboard of blanket. The insulating properties of blankets improve in vacuum because the spaces between fibers are evacuated.