Abstract: Method and apparatus for calcining fine-grained material such as in the manufacture of cement in which the raw material is subjected to the sequential steps of pre-heating, calcining and sintering. At least one of the stages is fueled by coal dust which has been ground and dried with a drying exhaust gas derived from one of the stages. In accordance with the invention, an exhaust gas fraction is withdrawn from one of the stages, and has a relatively high concentration of injurious substances such as alkalis and sulfur. This withdrawn exhaust gas fraction is then cooled by one of a variety of methods, and then treated for the removal of the injurious substances. Finally, the cooled gas fraction is used to dry the coal dust fuel by conserving energy which would otherwise be lost in the process.

Abstract: A worm centrifuge system is disclosed wherein a rotatably supported centrifuge drum is provided together with a conveyor worm rotatably supported within the drum. A drive motor is provided for the drum and a separate drive motor is provided for the worm. A centrifuge drum and conveyor worm are normally operated at different RPMs. The conveyor worm is driven by one of the motors through a planetary gear and a housing of the planetary gear is connected to the centrifuge drum. The other drive motor connects with the housing of the planetary gear by a belt system. A switchable coupling is provided to connect the input of the planetary gear to its housing during start-up and then selectively to disengage the housing from the input of the planetary gear after operating speed is attained and the other drive motor is energized. The maximum energy requirements for each of the drive motors is reduced, thereby reducing cost.

Abstract: The present invention is directed to a method for compressing and agglomerating coal dust without the use of bonding agents in which the coal dust is passed through a conventional roll press operating at a compressive force of at least 20 kilonewtons (kN) per centimeter (cm) of roll width. The high pressure conditions make it possible to secure suitable compression and agglomeration at temperatures below 200.degree. C.

Abstract: Method and apparatus for the thermal treatment of finely divided material for the calcination of cement wherein the material is preheated in a multi-stage heat exchanger and later passed to a calcining furnace. The material is partly deacidified in a pre-calcination zone before entering the sintering furnace where further calcining and sintering of the material is completed. A portion of the feed material is treated with rapidly oxidizing fuel components in a pre-calcination zone in a first stage and with more slowly oxidizing fuel components in a second stage, the more slowly oxidizing fuel components being a mixture of relatively fine granulated fuel particles of substantially uniform size and larger particles of briquetted or coarsely broken fuel.

Abstract: An apparatus to burn carbon bodies has at least two independently controllable electric resistance heating circuits, at least two temperature sensors and a comparator. Two or more regions of a selected carbon body can be independently heated by the two circuits. The actual temperature of each of those two or more regions can be monitored by corresponding temperature sensors connected to the comparator. The comparator controls each electric resistance heating circuit independently so as to minimize any difference between a preselected temperature and the actual temperature of each region.

Abstract: A casting consisting of a dehydrated agglomerate of particulate material and shaped such that one of its right angle projections is in the form of a trapezoid whose sides include angles greater than 90.degree., the sides being joined by means of curved surfaces.

Abstract: An arcuate shaped magnetic system is housed in a fixed cryostat within a rotating drum. A slurry containing magnetizable particles is charged into an operating area defined by the magnetic system at the lower part of the drum and magnetic particles adhering to the drum are removed as the drum rotates the same to a discharge location. The cryostat has an outer wall which conforms to the shape of the drum and houses a sector-shaped refrigeration tank. The refrigeration tank has an arcuate wall section conforming to the shapes of the cryostat wall and the drum and is positioned in close proximity to the outer cryostat wall only in the operating area in order to minimize inward heat transfer.

Abstract: Wall structure for a smelting stack is comprised of a cooling fluid flow pipe membrane layer comprised of a series of vertical, parallel arranged pipes extending between upper and lower manifold members. The pipe membrane completely surrounds a hot zone in the smelting stack. The upper and lower manifolds extend interiorly of the pipe wall membrane to define an alcove in which there is positioned a series of vertically arranged lengths of insulation cladding which are spaced from one another by gaps filled with fire-proof materials. The gaps contain elements of the pipe membrane layer directed interiorly of the pipe membrane. A waste-gas stack may be mounted directly adjacent the smelting stack with a common wall therebetween. The waste-gas stack wall comprises only a pipe membrane.

Abstract: Method and apparatus for drying and pulverizing coal which is to be used as a powdered fuel in the manufacture of cement. Air which has been heated in the cooling step of the cement making process is passed through a tertiary air conduit for delivery to a calcining step of the cement making process, and at least a part of the dust-laden air from the grinding step is introduced into the tertiary air conduit.

Abstract: A rotary mower has a cutting plate to which freely pivotal blades are attached by retaining pins. Instead of riveting the pins directly to a leaf spring which holds the pins in place, a keyhole slot is provided in each leaf spring and a narrow waist of the retaining pin fits into rectilinear portion of the keyhole slot and is held in position there by a holding plate riveted to the leaf spring. This allows case hardening of the entire retaining pin and prevents nonuniform stresses in the latter from causing breakage.

Abstract: A height adjuster for an agricultural implement, such as the crop pickup device of a field chopper, picker, thresher or like machine having an intake or pickup unit drawing the crop to a chopper or blower, has at least one movable front point or shoe which is swingable about an axis transverse to the direction of travel and rides on the ground. Within this shoe switches are provided to respond to the pivotal movements of the shoe and control a hydraulic cylinder for lifting or lowering the pickup unit to conform to changes in the ground contour.

Abstract: An installation for calcining finely divided particles such as for the preparation of cement including a building which houses a pre-heater, a relatively short rotary tubular kiln which receives the pre-heated particles from the pre-heater, and a rotary cooler which receives the discharge from the rotary kiln, the rotary cooler having a discharge end received in a portion of the building below the pre-heater, the discharge end of the rotary cooler being surrounded by sound absorbing material.

Abstract: A method and apparatus for the production of coal dust includes a connection between a pulverizing mill's exhaust gas output port and a transition region between a preheater region and a calcination region of a related calcination installation which uses the coal dust as a fuel.

Abstract: A method for the cementation of a metal from a solution containing metallic ions by the addition of a finely divided cementation medium, wherein the cementation reaction is carried out in a reaction chamber located in an oscillating reactor which is at least partially filled with agitation bodies inert with respect to the reaction, the agitation bodies having a maximum dimension in the range from 2 to 150 mm and being sufficiently large to transmit the oscillations of the reactor into the reaction chamber, the specific gravity of the bodies being appreciably greater than the specific gravity of the solids in the reactor. The method is particularly applicable to the cementation of copper.

Abstract: A wet settling machine having a jig screen has the separating liquid mechanically pulsed and the energy of the pulsations is stored in and released from sealed air chambers which open downwardly into the settling liquid.

Abstract: A wet settling machine for processing mineral mixtures, particularly fine-grained coal and other minerals, has the separating liquid energized into a pulsating motion with a basic wave and an upper harmonic superimposed on the base wave. The harmonic wave may proceed longitudinally with respect to the base wave or transversely with respect to the base wave. The base wave is pneumatically generated and the harmonic wave is mechanically generated.

Abstract: Apparatus for the thermal treatment of finely divided material for the calcination of cement wherein the material is preheated in a multi-stage heat exchanger and later passed to a calcining furnace. The material is partly deacidified in a pre-calcination zone before entering the sintering furnace where further calcining and sintering of the material is completed. A portion of the feed material is treated with rapidly oxidizing fuel components in a pre-calcination zone in a first stage and with more slowly oxidizing fuel components in a second stage, the more slowly oxidizing fuel components being a mixture of relatively fine granulated fuel particles of substantially uniform size and larger particles of briquetted or coarsely broken fuel.

Abstract: The invention relates to a method for burning fine-grain material, particularly for the manufacture of cement clinker from cement raw meal. The material is thermally treated in a multistage burning process with a pre-heating stage, a calcining stage with a high-degree of calcination, a sintering stage in a very short rotary kiln and a cooling stage. Fuel is introduced both into the sintering stage in the short rotary kiln as well as into the calcinating stage. Hot exhaust air from the cooling stage is supplied both to the sintering stage as well as to the calcining stage as furnace air. The invention also relates to an apparatus for the manufacture of mineral products of the burning process such as cement clinker.

Abstract: A method and apparatus for the production of a hydraulic binder of the type used for plaster and masonry mortar within a cement producing installation including a preheating zone and a clinker calcining zone. In accordance with the invention, the cement producing plant is modified to the extent of providing for the removal of a predetermined portion of the material being processed from at least one point between the preheating zone and the clinker calcining zone wherein the withdrawn material has a predetermined condition of activation so that it is useful alone or in a mixture with other ingredients in the manufacture of the binder.

Abstract: A solid sleeve worm centrifuge having a cylindrical separating portion and a conical discharge portion is provided with a static plate attached to the rotating worm in the area of transition from the cylindrical portion to the conical portion. The static plate prevents the backflow of solids already precipitated from the conical portion to the cylindrical portion of the centrifuge. Intensive dehydration of the separated solids is thus achieved, so that the solids may be stored directly or processed further without additional liquid removal treatment. A liquid withdrawal conduit is provided in the cylindrical portion of the centrifuge to continuously remove liquid separated from a solid-liquid mixture.