Abstract: A compact, hydraulically operated pressure valve for selective opening and closing of conduits or the like is provided which can withstand extremely high pressures in use, is easily repaired and/or replaced, and is low in cost. The valve includes a thin, circular metallic diaphragm which is mounted for bulging in response to pressure directed thereagainst, along with cavity structure adjacent to and in communication with one face of the diaphragm; in use when the diaphragm is located in closing relationship to a pressurized conduit, hydraulic fluid directed to the chamber establishes a desired pressure differential across the diaphragm such that the latter experiences only a desired pressure. The bulging of the diaphragm also causes the latter to sealingly engage a sharp marginal sealing edge associated with the valve, to further enhance the integrity of the closure effected thereby.

Abstract: Modular, conveyor-type heat exchange apparatus is provided which is especially adapted for handling large volumes of shale rock and preheating incoming raw shale using hot, spent shale from a commercial processing operation. The apparatus includes an elongated heat exchange zone having a plurality of separate, interconnected, insulated modules; two superposed, oppositely moving sections of an endless conveyor pass through the zone and respectively support hot and raw shale material for heat exchange therebetween. The conveyor includes spaced, interconnected, shale-supporting triangular elements which facilitate gas flow between the conveyor sections in the heat exchange zone. In preferred forms, the modules present restricted inlet and outlet throats, and are provided with slow moving fans for circulation of air currents between the conveyor sections without creation of chimney-like drafts along the length of the modules.

Abstract: An improved, multiple-well screen structure is provided which is especially adapted for use in a large scale reactor employed in oil shale processing operations. The screen includes a plurality of adjacent, juxtaposed concavities each presenting perforate sidewalls and a lower outlet opening. Preferably, the screen is circular in plan configuration and includes three sector-shaped (in plan) concavities respectively formed from cone sections. The sections are interconnected along arcuate, reinforced juncture lines to present a structurally sound material supporting, gas-pervious screen which can be easily and completely emptied using only gravity-induced material flow.

Abstract: A low cost, high efficiency process for treating oil shale is provided which allows essentially complete recovery of the valuable hydrocarbon fraction of the shale, including light ends, without direct firing of the shale or use of other expensive processing steps heretofore proposed. In preferred forms, the oil shale is heated in a closed heating system using circulating, oxygen-free gases until the shale "break point," or temperature at which the hydrocarbons begin to vaporize from the shale, is reached; at this point the system is slowly depressurized and hydrocarbons are simultaneously released to a condensation stage for the recovery thereof and control of circulating fan horsepower. Steam may also be added to the circulating system to further purge hydrocarbons from the shale and provide additional control of fan horsepower.