Rotary plug

Purpose: To provide a sealing device capable being fitted without any trouble in the vicinity of the lower end of a rotary plug, thereby to minimize the space of ingression of sodium vapor into the sliding surface of the rotary plug. Constitution: A slightly large, annular space is formed at the lower part of an annular space between the sliding surfaces of a large rotary plug and a small rotary plug. An annular body having a rectangular section is interposed in said former space. Sodium vapors generated from the sodium solution level while the reactor is in operation make ingress together with the cover gas through the annular space formed on the sliding surfaces of the large rotary plug and the small rotary plug, and in accordance with the ascent, the vapors and gas are cooled and condensed. However, since the ascent of the sodium vapors is checked by a seal ring interposed in the annular space in the vicinity of the lower part of the rotary plug, there is no ingress of a large quantity of sodium vapor. (Yoshihara, H.)