Abstract: A circular solvent extractor useful in a commercial process for the removal of bitumen from tar or oil sands or other solvent extraction processes requiring high tonnage throughput. The extractor comprises two major segments that are stationary, namely, a ring-shaped roof member and a ring-shaped drain trough means positioned therebeneath, and one segment that is movable which comprises a pair of continuous, spaced-apart sidewalls having a plurality of spaced-apart, liquid permeable, process cells rotatably attached to the sidewalls. The sidewalls and their attached process cells are movable about a circular trackway for travel between the fixed hood and drain trough means, forming an annular process chamber therearound. The annular chamber is sealed by upper and lower, circumferential liquid seals coacting between the moving sidewalls and the stationary hood and drain trough means to prevent the leakage of solvent vapors therefrom.

Abstract: A traveling grate consisting of individual pallets each supported on four wheels and independently connected to continuous side walls so that the pallets can pivot down away from and back toward the continuous sidewalls as the rear wheels follow a depressed portion of the trackway in the discharging zone of a retort. The wheels travel in a tunnel which is isolated from the processing zone of the grate retort but is in fluid communication with the charging and discharging zones. The processing zones are also separated from the remainder of the retort by transverse seals formed by false windboxes. Gas leakage from the processing zone is minimized by the tunnel-encapsulation of the retort's processing zone.