VACUUM HEAT TREATMENT FURNACE

摘要

PURPOSE:To reduce the time for vacuum evacuation by providing auxiliary heating elements, and heating a heat insulation structure in which the steam infiltrated in a vacuum vessel while the vessel is open is adsorbed thereby evaorating the adsorbed moisture. CONSTITUTION:The outdoor air infiltrates in a vacuum vessel 1 and steam is absorbed in a heat insulation structure 5 in the stage of charging a heat treatment object into the heat treatment space 3 in the vessel 1. The moisture adsorbed in the structure 5 is heated and evaporated by a main heating element 4 and the auxiliary heating elements 5 provided on the outside peripheral surface of the structure 5, and is quickly discharged to the outside of the vessel 1. The time for vacuum evacuation is considerably reduced by the above-mentioned device.