Vertical heat treating apparatus

Abstract

A vertical heat treating apparatus includes a cap body, which is movable up and down, for sealing a treatment vessel that holds objects to be treated. A rotary loading device is provided with a rotary shaft which extends into a through hole provided in the cap body, and a magnetic fluid seal member is provided around the rotary shaft. Heat-exchange media, such as water or ethylene glycol, is circulated within the rotary shaft, preferably to cool the rotary shaft. A temperature sensor may be provided in a housing for the rotary shaft, such that when the temperature exceeds a set temperature, the flow rate of the heat exchange medium is increased. Baffle plates may be provided above an upper surface of the cap body and opposed to the through-hole in the cap body. In one preferred embodiment of the invention, nitrogen gas is circulated through the through-hole in the cap body to prevent corrosive gas from contacting the shaft. Circumferential grooves are defined around the rotary shaft at locations where the heat exchange medium is admitted and discharged from the rotary shaft. Preferably, the heat exchange medium is circulated in the rotary shaft above and below the level of the magnetic seal.