Abstract: An apparatus for processing materials provides a material processing chamber, formed from an enclosure having a top and a bottom. The bottom has an opening therein, and a shaft extends through the opening and into the chamber. A bearing assembly may be arranged about a lower portion of the shaft, the bearing assembly including a bearing extension arranged about a portion of the shaft. The bearing extension has a portion thereof extending through the opening of the bottom of the chamber. A first seal assembly forms a first seal between the bearing extension and the bottom of the chamber, and a second seal assembly forms a second seal between the bearing assembly and the shaft.