High temperature sealing device

Abstract

A gas-tight seal for rotating high-temperature devices, comprising one or two seals of the labyrinth type, located on opposite sides of a hopper through which the shaft passes. Each labyrinth uses a plurality of rings as seal members. One set of the rings, separated by ring-shaped spacers, is rigidly attached to the hopper wall where the shaft passes into the hopper. The other set, of smaller diameter and interfitted with the first set, is slidingly fit to the rotating shaft, possibly with driving splines, but not fastened rigidly to either the shaft or the hopper. In an alternate embodiment, the spacer rings are replaced with graphite rings which contact both the stationary and rotating rings. The hopper is filled with particulate solid matter which is capable of withstanding the temperatures to be encountered, such as mica flakes or graphite flakes, or ash or char. The particulate matter forms a seal around the shaft itself, and fills the gaps in the labyrinth. If the application requires that the seal hold in pressure (as opposed to vacuum), the hopper is sealed.