Abstract: The present invention generally pertains to an agitating element for agitating low-to-medium-viscosity liquids. The agitating element comprises an inner main blade and an outer side blade, and the two blades are integrally constructed. The main blade is angled with respect to the rotation axis of the agitating element, while the side blade is angled with respect to the rotation plane of the agitating element. The agitating element according to the current invention enables high hydraulic efficiency especially in a vertical direction so as to accomplish thorough mixing of the material with a minimal energy input.

Abstract: Oil-containing solids are dried and heated by contacting them in a drying zone with superheated steam admitted to the zone at a temperature in excess of 200.degree. C. The heated solids may be distilled to remove hydrocarbons therefrom and the resulting proceduce and/or combustion products of the distillation or other combustion products are used to heat a mixed vapor remainder, after separation of said carbon from the vapors formed during the drying, to the temperature of 1200.degree. C. for recirculation to the drying zone.

Abstract: The dry distillation of oil shale and like volatilizable materials as carried out by intimately mixing it with a fine-grain hot heat-transfer medium. According to the invention the hot distillation residue is passed in direct heat exchange with a cooling gas and the latter is utilized as one component of a preheating mixed gas which is passed in uniflow with the devolatilizable material through at least one riser. Hot combustion gases can make up other components of these mixed gases.

Abstract: The rotary hearth furnace plant for heating granular high-carbon solids comprises an approximately funnel-shaped hearth, which rotates on a vertical axis and has a central outlet, which is disposed over a rotary table, on which the heated solids are moved by means of blades to an exit. The outlet of the rotary hearth furnace is disposed over the radially outer portion of the rotary table, which has a raised rim and a centrally disposed exit. A gastight hood is disposed between the rim of the rotary table and the rotary hearth.

Abstract: In a process of recovering oil from oil-containing minerals on a traveling grate, hot gases are passed through the bed in a retorting zone, oil is separated from the retort gases in a separating stage, solid carbon in the retorted bed is burnt in a succeeding combustion zone by means of oxygen-containing gases passed through, gases from which the oil has been removed in the separating zone are passed through the bed in a succeeding cooling zone and the heated gases are recycled to the retorting zone.

Abstract: Oil-containing materials and part of the hot burnt material which is available after the combustion of solid carbon are charged into a retorting shaft reactor and the oil-containing mineral in the mixture is heated to the retorting temperature.

Abstract: Tubing is made by continuously pulling steel strip at a predetermined feed speed from a supply, shaping the strip into a multilayer tube of a predetermined mass per unit length, and advancing the tube at the feed speed through a soldering station. The strip is coated with a solder-type material and an electric current is passed through the tube between a contact engaging the tube in the station and a contact engaging the tube downstream of the station to fuse the solder and tube together. The contact outside the soldering station is displaced so that the spacing between the contact is varied substantially proportionately with the product of the feed speed and the predetermined mass per unit of length of the tube. Downstream of the soldering station the tube and solder are cooled to bond the tube together.