A method and device for the combined manufacturing of cement clinker and calcined clay, in a cement manufacturing line by the steps: providing, preheating and precalcining a cement raw meal in a preheater and calciner section, sintering the precalcined cement raw meal in a rotary kiln and cooling the resulting cement clinker with a counter current air stream in a clinker cooler, and in a clay manufacturing line by the steps: providing and preheating a clay raw material in a heat exchange section, and calcining the preheated clay raw material suspended in gas in a flash calciner. Hot air from the cooler is divided into a first combustion air stream for sintering the cement raw meal and a second combustion air stream for calcining the clay raw material. Exhaust gas from calcining clay raw material is fed into the calcination of the preheated cement raw meal.

An electrically controlled valve which can be operated using a programable controller. A cooperating pair of the electrically controlled valves can be used in a Regenerative Thermal Oxidizer (RTO). The electrically controlled valve has two seats, and a blade which can move between a first position contacting the first seat and a second position contacting the second seat. The blade is moved by an actuator which is controlled by a variable frequency drive (VFD). A control computer continuously monitors the operation of both valves and halts operation of the system upon detecting a fault (error). The motion of the blade is programmed such that force of impact on the seat is reduced. Once the blade is seated, a brake is engaged which maintains the stationary position while utilizing relatively low power.

Provided is a system for recovering waste heat discharged from distillation columns, incinerators, blast columns, smelting columns, and the like at relatively low temperatures to produce hot water in high efficiency, which can be used in various industrial fields. The investment and operating costs of the waste heat recovery system are relatively low as compared with the conventional systems.

A method for calcination of a carbon dioxide rich sorbent (containing CaCO.sub.3) includes combusting in a furnace a fuel with an oxidizer, supplying heat transfer (HT) solids into the furnace and heating them, transferring the HT solid particles from the furnace to a reactor having a rotatable container, supplying a carbon dioxide rich solid sorbent (containing CaCO.sub.3) into the rotatable container, rotating the rotatable container for mixing the solid particles and the carbon dioxide rich solid sorbent for transferring heat from the solid particles to the carbon dioxide rich solid sorbent and generating carbon dioxide and carbon dioxide lean solid sorbent (mainly CaO), discharging the carbon dioxide and the carbon dioxide lean solid sorbent from the rotatable container and the subsequent classification of the HT solids from the lean sorbent.

A method for denitrification of flue gases and a system, wherein flue gases generated in a rotary kiln are conveyed to a calcining zone for the deacidification of raw cement meal. Aqueous ammonia solution, ammonia, or ammonia-releasing substances for denitrifying the flue gases injected into the calcining zone according to the method of selective non-catalytic reduction (SNCR), and the flue gas stream, together with an ammonia slip generated during the denitrification, is passed through a heat exchanger and through at least one dedusting device. The flue gas is guided through a exhaust gas line via a catalyst for the decomposition of excess ammonia with residues of nitrogen oxide in accordance with a method of selective catalytic reduction (SCR), wherein the catalyst is arranged in a reactor provided in the exhaust line, and is no larger than is required for a sufficient decomposition of the ammonia.

Included are: a direct reduction furnace for reducing iron ore directly into reduced iron using a high-temperature reducing gas including hydrogen and carbon monoxide, an acid gas removal unit having an acid gas component absorber for removing, with an absorbent such as an amine-based solvent, acid gas components (CO.sub.2, H.sub.2S) in a reduction furnace flue gas discharged from the direct reduction furnace, and a regenerator for releasing the acid gas, and a degradation product removal unit for separating and removing a degradation product in the absorbent used by circulating through the absorber and the regenerator.

Methods and systems are provided for extracting and utilizing the energy contained in molten slags generated from metal producing and refining operations. The energy is extracted while the slag is contained within a containment vessel, such as a slag pot, after the slag has been discharged from a furnace. The energy is accessed by immersing into the slag a temperature-resistant treatment vessel, such as, a cylindrical vessel made of graphite, having an internal cavity. The energy from the slag is transmitted by direct contact with the surface of the treatment vessel. The treatment vessel and slag may be moved relative to each other to overcome the low thermal conductivity of the slag. Any substance placed within the cavity is thereby heated without directly contacting the molten slag. The methods and systems provide for high temperature chemical reactions, energy conversions, or transfer operations within the internal cavity.

A device for treating bulk material with a gas, the device including a grate through which gas can flow from an under-grate space to the upper side and which conveys a layer of bulk material in a conveying direction from a loading end to a discharge end. The grate has a plurality of mutually adjacent rows, each of which includes at least one bar that is elongate in the conveying direction and may be moved alternately back and forth in the conveying direction. Driving is controlled such that the forward stroke of the at least one bar of two adjacent rows takes place at the same time, while the rearward stroke of the at least one bar of two adjacent rows takes place at different times.

Disclosed is a method of operating a furnace containing a charge to heat the charge, comprising wherein gaseous oxidant comprising 60 vol. % to 85 vol. % oxygen is passed through a heated regenerator and into the furnace, so that the oxidant is heated to emerge from an oxidant port at a temperature of 500 C. to 1400 C., and gaseous fuel is fed into said furnace through two or more fuel ports; and the heated oxidant and fuel are combusted in the furnace to produce gaseous hot products of said combustion which heat the charge; and then the flow of oxidant through the regenerator into the furnace is discontinued, and said combustion products are passed into said oxidant port and through and out of said cooled regenerator to heat said regenerator, wherein the temperature of the combustion products that pass out of said regenerator is at least 500 C.; under dimensional and operational conditions which attain functional and economic advantages.

A pure oxygen direct combustion system using a liquid metal according to the present invention comprises: a reactor for receiving a liquid metal; a heat exchanger, connected to the bottom of the reactor, for exchanging heat for the liquid metal; a circulation pump, connected to the heat exchanger, for circulating the incoming liquid metal; a nozzle, connected to the circulation pump and disposed on the reactor; a reduction unit, connected to the circulation pump, for performing a reduction for the oxidized liquid metal; and a separation unit, connected to the reactor and the reduction unit, wherein the particles of the liquid metal injected from the nozzle are subjected to sensible heat from the gas generated from the reactor, heat-exchanged by the heat exchanger and regenerated by the reduction unit, and then supplied back to the reactor.