Apparatus with moving bed pressure letdown stage for recovering retorted

Abstract

A dry sealing leg apparatus is comprised of four chambers through which a moving bed of retorted shale particulates from an oil shale retort is passed serially: a surge chamber, a gas injection chamber, a seal leg chamber, and a gas disengaging chamber. In the gas injection chamber, a sealing gas penetrates the moving bed of shale and divides into two portions. One portion travels countercurrently to the shale through the surge chamber and enters the retort at a positive pressure to seal product gases therein. A second portion travels co-currently with the shale through the seal leg chamber and gas disengaging chamber and exits at a pressure less than that of the retort, having been reduced in pressure by resistance to its passage through the shale. A method is provided wherein shale particulates are retorted, then passed through the dry sealing leg to reduce pressure, and crushed at a lower pressure than the operating pressure of the retort, following which the crushed retorted particulates are transported by an entraining gas stream to a fluidized combustor in which a substantial proportion of combustible materials on the shale particulates is burned to release heat energy for recovery from the flue gases.