Method and apparatus for retorting oil shale

In apparatus for recovering oil products from raw oil shale and the like, the combination comprising:

• an elongated, generally cylindrically shaped housing having heat-conductive walls with inner surfaces defining a retort chamber, said housing having a longitudinal wall portion, an upper end wall portion, a lower end wall portion, and an outlet spaced a distance from the inlet along said chamber, said retort housing and chamber being sloped downwardly for gravity flow of the oil shale therethrough from said inlet to said outlet;
• a rotating member in said retort housing having conveyor blade portions extending out from a central rotary shaft portion arranged to force the incoming raw oil shale countercurrent to the gravity flow, said conveyor blade portions having a peripheral surface area defining an annular flow passage between said inner surfaces and said peripheral surface area for crushing oil shale and confining the crushed oil shale to a layer to which heat is applied from said inner surfaces;
• means for heating the oil shale moving in said annular flow passage as the oil shale travels through said flow passage from said feed portion to said discharge portion by heating said inner surfaces to produce oil product vapors in said retort chamber and resulting in spent oil shale that is delivered via said annular flow passage by gravity flow to said discharge portion;
• a condenser coupled to said retort chamber arranged for removing the oil product vapors therefrom at different points of elevation along said housing and condensing said vapors into a liquid form;
• and
• valve means normally closing said outlet portion that is selectively opened, while keeping the inside of said retort chamber closed to the atmosphere, to discharge the spent oil shale.

In a method of recovering oil from oil shale and like materials, the steps of:

• controllably supplying selected amounts of raw oil shale to an upper feed inlet of a generally cylindrical retort chamber having heat-conductive walls with inner surfaces and a lower outlet and generally inclined so that the shale will gravitate from said inlet toward said outlet;
• crushing the raw oil shale between moving peripheral surface areas on a rotating member in the chamber and said inner surfaces of said walls defining said chamber while conveyor portions on said rotary member are moved in a direction to cause shale to move countercurrent to gravity flow in the retort chamber, and confining the crushed oil shale to a layer that travels from the upper feed inlet to and through said lower outlet by gravity flow while heat is applied thereto through said walls in the retort chamber to retain oil product vapors therein;
• and
• removing the oil product vapors from an upper portion of said retort chamber.