Abstract: A side stream of hot blast air is used to preheat oxygen at a heat exchanger. The resultant hot oxygen is injected into a tuyere of a blast furnace with pulverized or granular coal. The cooled side stream may be recombined with the hot blast air for injection into the tuyere, fed to the stove as part of the cold blast air, or fed to stove for combustion with blast furnace gas.

Abstract: An installation for soldering or for heat-treating workpieces (1) under a protective gas atmosphere, includes a workpiece transportation apparatus (2), an entrance (3) into the installation and an exit (4) out of the installation, a combustion-gas or heating-gas stream (B) which is conducted separately from the protective-gas stream (S) and brings the protective-gas stream (S) to operating temperature, and comprising an insulating means (5) which surrounds the installation. A considerable amount of energy is saved in that the combustion-gas or heating-gas stream (B) and the protective-gas stream (S) have approximately corresponding heat capacities and can be conducted through the installation in counterflow.

Abstract: A metal heat treatment method includes quenching a workpiece by blowing an inert gas onto the workpiece, adjusting the temperature of the inert gas to approximately an isothermal holding temperature of the workpiece for transformation of the workpiece, holding the isothermal holding temperature within a margin of error of approximately plus or minus five degrees Celsius for a given period, and performing a metal heat treatment with the isothermal holding temperature kept statically or dynamically by varying the temperature of the hot-gas.

Abstract: Support assembly for supporting heat regeneration checker work in a hot blast stove for a blast furnace. The assembly includes a supporting grid for supporting the checker work, and supporting columns for supporting the supporting grid. The assembly includes a cast iron material. The cast iron material includes a ferritic matrix and a dispersion of graphite particles wherein the shape of the graphite particles is substantially vermicular or nodular.

Abstract: A non-oxidizing heating method and apparatus in which a non-oxidizing gas of high temperature is continuously generated and supplied into a furnace by changing over a plurality of heat storage type heaters alternately while repeating an operation in which one heater stores heat and the other heater heats and blows the non-oxidizing gas. Since it is possible to heat by producing a completely non-oxidizing atmosphere within the furnace, the method and apparatus can be effectively utilized in furnaces which require heating in a non-oxidizing atmosphere, for example, various furnaces such as a ladle, tundish, etc. used in a field of steel manufacturing and continuous casting, and various furnaces used in a field of heating and heat treatment of metallic materials, and thus, it is effective to achieve reduction of operational cost, improvement of product quality, and improvement of product yield.

Abstract: A continuous checker column is molded and formed in situ inside a regenerative chamber, thereby eliminating the need for large numbers of individual, preformed checker bricks. A plurality of rigid molding rods or flexible cable rods are passed through, or hang from, a template installed in or above the empty checker chamber portion of a regenerative chamber. The molding rods are sized, shaped, and spaced to correspond substantially to the size, shape and spacing of the openings desired in the checker column. Then, a refractory material is injected into the checker column and allowed to harden. The molding rods are at least partially retracted, leaving the desired openings in the hardened refractory material. The injection and retraction steps can be repeated, as necessary, until the entire checker column has been formed.

Abstract: In the construction of a hot blast stove, walls are made of pre-formed and baked bricks. At the joint between two walls, cast joining elements of complex shape are incorporated. The cast joining elements may be cast in situ. This avoids the need for pressing joining bricks of a variety of shapes.

Abstract: A burner is mounted on top of a regenerator by a pipe connector.The combustion chamber of the burner communicates with the furnace interior via a tunnel and with the interior of the regenerator comprises a packing of ceramic material with a tubular casing of ceramic fibers. An electrical heating element is mounted in the pipe connector or is situated near the top of the packing.

Abstract: Combustion air and fuel gas used for firing blast furnace stoves is preheated by utilizing the heat of waste gases resulting from such firing. The combustion air and fuel gas are passed through respective heat exchangers in heat exchange relationship with the waste gases, thereby preheating the combustion air and fuel gas. The combustion air, after passage thereof through the respective heat exchanger, is further preheated by an externally fired recuperator. The flue gases from the externally fired recuperator are fed to the waste gases before preheating of the combustion air by such waste gases. The external firing of the recuperator is controlled as a function of the final preheated temperature of the thus twice preheated combustion air.

Abstract: The present invention relates to a method and an apparatus for the recovery and recycling of heat from hot exhaust gases, specifically from exhaust gases in metallurgical processes and from warm gases having an exiting temperature of below about 800.degree. C. According to the preferred embodiment of the present invention, warm or hot exhaust fuel gases transfer their retained heat to the lower portions of vertically positioned, capillary-type action heat transfer pipes. Cold air is then directed past the upper portion of the heat pipes, thereby transferring the heat of the heat transfer pipes to the cold air. The now heated air gains further heat, prior to introduction into the blast furnace, by passing over, previously heated refractory gratings.

Abstract: In a support construction for a hot blast main which is connected by respective branches to the outlets of a plurality of hot blast stoves of a blast furnace, the main is suspended on each stove by means of a rod system secured to a stiffened transitional region between the wall and dome of the stove and having an outer end located above the main. The main is suspended from this outer end, to which at least one strut extends from the stove wall adjacent the hot blast outlet. A travelling crane track is secured to the lower side of the rod systems so as to extend above valves incorporated in the hot blast branches. Thus these valves can easily be removed and replaced.

Abstract: A cupola system for production of gray iron employs otherwise wasted heat to preheat fuel, pig iron, flux and compressed air fed into a melting furnace, by diversion of melting furnace exhaust-gases through a preheating furnace containing feeding conduits for the fuel, pig iron and flux, and for the compressed air; the preheating furnace is laterally inclined downwardly from a point of exhaust to a chimney, to the melting furnace; the diverting means includes a closed, downwardly concave reflecting top over the melting furnace, and the preheating furnace has a concave roof; an important provision of the invention is employment of a maximum number of conventional size and shape tuyeres in a radial array in the melting furnace.

Abstract: A regenerative air preheater includes a masonry casing having therein a combustion chamber and a checker shaft with checker bricks, and a separating wall between the combustion chamber and checker shaft. A space is provided between the separating wall and the checker bricks. Insulating material comprising fireproof fiber material is positioned within the space. The insulating material is structurally free of the separating wall.

Abstract: A blast stove having adjoining combustion and checker chambers, for use with a blast furnace. A support structure, mounted within the checker chamber, supports tiers of interlocked checkerbricks. The support structure includes vertically extending columns which loosely engage a series of transversely extending girders. The girders supportively engage a plurality of grid bar assemblies, each assembly including a plurality of grid bars maintained in a spaced relation by transverse rods and spacers welded to the bars and further including interlocking apparatus for engaging the underlying girders and an adjacent grid bar assembly. The grid bar assemblies support a plurality of grid shoes having grid assembly engaging grooves for interlocking the grid shoes to the grid bar assemblies. The top surface of the grid shoes include recesses which receive bosses located on the underside of the checkerbricks so that the first layer of checkerbricks, is engaged by the shoes.

Abstract: A mixing chamber for mixing hot blast exiting from a hot blast stove with cold blast from a supply thereof to provide a uniform blast mixture adapted to be introduced into a blast furnace. The chamber comprises an open ended tubular member defining openings at opposite ends thereof, one of these openings being an entry into the tubular member and the other being an exit therefrom. The entry is adapted to have introduced therethrough hot blast exiting from a hot blast stove while the exit is adapted to communicate with the blast furnace. The tubular member is provided with a pair of diametrically opposed passageways therethrough, each of which is oriented tangentially with respect to the inner surface of the tubular member.

Abstract: A conduit, specifically a hot-blast main for a blast furnace, is supported on a vessel specifically a hot-blast stove, into which it is connected by a branch, by means of at least one vertical support member and a framework mounted on the vessel and carrying the support member. The framework includes a strut or tie element extending from the end of the support member to the point of connection of the conduit branch into the furnace. The support member, which may be a rod hinged to the framework, may suspend the conduit from above or support it from below. This construction is simple and provides support for the conduit without problems due to vertical movement caused by thermal expansion of the point of connection into the vessel.

Abstract: The swirling burner comprises a vertical combustion chamber and an annular blast member located beneath the combustion chamber and provided with a central cylindrical space and a plurality of alternately superposed fuel gas passages and air passages. These passages are communicated with the cylindrical space through blow openings which are inclined in the same direction with respect to the radii of the cylindrical space. In a modification, the burner is further combined with straight blowing type burner for promoting the effect of the air-gas mixing.

Abstract: Intercrystalline stress corrosion of the walls of heat exchangers employed to produce hot air for injection into a blast furnace, particularly the wall of the passage interconnecting the combustion and heat exchange chambers, is avoided by eliminating pressure differentials across the walls. Also, the walls of the heat exchanger are heated to a temperature above the condensation point of deleterious vapors present or formed in the apparatus to thereby further minimize the possibility of occurrence of stress corrosion.

Abstract: A hot blast stove apparatus comprising a hot blast stove having a discharge passage for hot blast gases, and a temperature equalizer material in the passage such that the hot blast gases discharged from the hot blast stove, gradually lowering in temperature with lapse of time, are continuously supplied with heat from the equalizer material and the hot blast gases discharged from the passage are at an equalized temperature.