Abstract: The invention relates to a method and equipment for the continuous sintering of mineral material in a sintering furnace (S). In the method, a material bed (2) is formed on a conveyor base (1), the material bed (2) is conveyed by the conveyor base (1) through the process zones (I-VII) of the sintering furnace that have different temperatures, the zones including at least one drying zone (I), at least one cooling zone (VII), and at least one other process zone (II, III, IV, V, VI) between the said drying zone and cooling zone, and gas is conducted through the conveyor base and the material bed (2), when the material bed travels through the process zones (I-VII), and gas is circulated in a circulation gas duct (3) from the last cooling zone (VII) to the drying zone (I). Part of the gas flow that is conducted to the drying zone (I) in the circulation gas duct (3) is removed as an exhaust gas flow (B) by the exhaust gas blower (5) of an exhaust gas duct (4).

Abstract: In order to increase energy efficiency in an industrial furnace (1) operated by heating gas and protective gas for thermally treating materials, a first burner (3.1) is actuated for heating with priority over a second burner (3.2), the second burner (3.2) is engaged additionally and operated when the output from the first burner (3.1) falls below the level necessary to heat the industrial furnace (1) up to a temperature setpoint, and the second burner (3.2) is switched off when the temperature setpoint has been reached.

Abstract: A fuel delivering terminal (1) is disclosed adapted to be connected to a delivery end of a combustion lance (3) of lime regenerating ovens, wherein D is the external diameter of the terminal (1) and is greater that the internal diameter d of the delivery end of the combustion lance (3); a combustion lance equipped with the terminal (1) and a system and a process for controlling the fuel supply flow through such lances are also disclosed.

Abstract: A premix burner assembly for heating the combustion chamber of a dryer for an HMA plant, soil remediation plant, or the like is designed to meet the very low emission limitations that are imposed in certain areas such as the southern portion of California. The burner assembly includes a burner, a primary nozzle, an air source connected to the burner, a fuel source, and a fuel injection system connected to the fuel source and to the burner. Premixing is achieved through the supply of a gaseous fuel from the fuel injection system into the burner upstream of the primary nozzle so as to lead to nearly complete premixing of the air and fuel prior to discharge into the combustion chamber, thereby permitting combustion of the fuel with only very small amounts of excess air. Burner efficiency is increased and emissions are further reduced by employing air distribution and control devices upstream of the fuel injection system and by carefully controlling the supply of both air and fuel to the burner.

Abstract: A flue wall, and method for making same, adapted to be readily assembly with like walls and other components to form a battery of heated comparments in a pit in which carbon anodes, such as used in the manufacture of alumina are baked. The wall includes upper and lower sections each having two interlocked parallel panels, of pre-cast monolithic construction. The upper and lower sections interfit to form a hollow flue confining the flow of hot gases generated by fuel burners. Baffles across the flue channel the gases in a serpentine-like path. Inclined apertures at spaced locations permit gases envolved by the anodes as they bake to flow into the flue and combust with the hot gases from the burners. Lifting lugs are provided to enable the wall to be fabricated at a site remote from the bake pit and transporated to the pit in form. In one embodiments the panels in each section have symmetrical interfacing reliefs of baffles, vacuum supports and edgewall portions to facilitate casting and assembly.

Abstract: A method for removing magnesium and calcium from sodium sulfate solutions to render the solutions suitable for membrane processing, which comprises adjusting the pH of the solutions to about 11 to 13 with sodium hydroxide to form a precipitate containing the bulk of the magnesium and the calcium, removing the precipitate from the resulting partially purified sodium sulfate solution, and contacting the partially purified sodium sulfate solution with a polystyrene divinyl benzene copolymer chelating cation exchange resin having an aminophosphonic functional group and having sodium as the exchangeable cation, to remove essentially all of the magnesium and the calcium from the partially purified sodium sulfate solution.

Abstract: A high temperature fan plug for a jet heat recuperator includes inner and outer face plates spaced apart by tubular spacers extending between the plates to form a heat insulative cavity. A fastener bolt extends from one face plate through a tubular spacer and projects from the other face plate. A spring with washers at opposite ends thereof is compressed by nut members on the end of the bolt which projects from the face plate for clamping the outer and inner face plates against the spacers. A hub structure carried by the inner and outer face plates receives a seal. The face plate exposed to high temperatures in the recuperator extends between spaced apart rings that are secured to a rim that is in turn carried by the other of the face plates. The rings slidably engage the outer peripheral portion of the face plate exposed to the high temperature environment.

Abstract: An apparatus for soaking steel pieces including cold steel pieces and hot steel pieces. The apparatus is of the type which includes: a soaking furnace for subjecting the steel pieces to a soaking treatment; a preheating chamber for preheating the cold steel pieces before the cold steel pieces are introduced into the soaking furnace, the preheating chamber being connected to the soaking furnace for receiving waste heat from the soaking furnace for the preheating treatment and having an outlet portion for discharging the cold steel pieces; and a mechanism for introducing the steel pieces into the soaking furnace and for advancing the steel pieces through the soaking furnace.

Abstract: A gas flows through a pipe employed for intensive heat and material transfer, wherein the pipe has a length equal to 0.5 to 100 meters. The pipe features a gas inlet and two gas outlets. A solid body charge interacting with the gas flow enters at an inlet position in the pipe, passes a plurality of baffles which reduce the cross section in the pipe, and emerges from the pipe at the end position. Together with the surface of the solid body charge, the baffles form gaps of 3-50 mm which reduce the boundary layer of gas on the charge limiting the heat or material transfer. Between each pair of neighboring baffles are chambers in which the gas rotates and thus strikes the charge repeatedly. As a result the efficiency of material and heat transfer is further improved. With this countercurrent system the solid body can take up and release heat during its passage through the pipe and can take up or release material according to the character of the gas flowing in the inlet.

Abstract: A device for thermally treating scrap employs a charging facility for conveying scrap to a furnace chamber. The charging facility is fitted with a waste gas flue and a loading port and has a pre-loading space in which the scrap is pre-heated. The device is easily operated and can be run with relatively little loss of energy by having the pre-loading space of the charging facility releasably connected to the furnace chamber and/or waste gas flue such that the pre-loading space is fed with waste heat from the furnace chamber. Preferably the pre-loading space is part of a waste gas or waste heat circuit. The pre-loading space is also provided with an extendable unit which can be pushed into the mouth or loading port of the furnace for feeding the scrap to the furnace.

Abstract: A reverberatory furnace for melting aluminum or other metals which includes a preheater (12) which utilizes exhaust flue gasses from the furnace (10) to preheat the metal before it enters the furnace. A set of horizontal flue ducts (18, 20, 22) conduct the flue gasses to a preheater chamber (26) where they heat the metal. An air entrance port (50) is provided in the preheater chamber (26) to allow secondary combustion of the volatile flue gasses for additional efficiency.

Abstract: An apparatus for preheating steel scrap comprises: a preheating vessel, having an open top and a bottom lid capable of being opened and closed, for receiving and preheating steel scrap, said preheating vessel being adapted to receive steel scrap to be preheated from said open top and to discharge the steel scrap preheated in said preheating vessel by opening said bottom lid; a hood downwardly flaring for covering said open top of said preheating vessel, said hood being movable from said open top of said preheating vessel and adapted to introduce high-temperature waste gases discharged from a steel-refining metallurgical furnace into said preheating vessel; a pit for housing said preheating vessel, said pit being provided with a duct for discharging to the outside said waste gases discharged into said pit from the bottom of said preheating vessel after preheating said steel scrap received in said preheating vessel; and, a canopy for sealing the gap between said pit and said preheating vessel housed in said pit

Abstract: An apparatus for the heat treatment of a material passing through a plurality of treatment zones using a heated gaseous treatment medium conducted in a substantially closed circuit through these zones. A heat exchanger is associated with each treatment zone. The heat exchanger defines, in an operative relation with the respective treatment zone a medium discharge path and a medium replacement path which paths are arranged in a heat exchange relationship. The fractional portion of a treatment medium discharged from each treatment zone transfers its heat and energy to the fresh replacement medium. A throttle or flow control in the medium replacement path for each treatment zone permits individualized control of draft and medium turnover according to the different conditions prevailing in each zone. A filter is also provided to prevent impurities in the medium discharge flow path from entering the heat exchanger.

Abstract: A heated soaking furnace, a chamber for preheating cold steel pieces in communication with said soaking furnace, means for transferring a portion of the heat from the furnace to the chamber, means for moving the steel pieces through the chamber to preheat the steel pieces and means for conveying the steel pieces from the outlet of the chamber to the inlet of the furnace.

Abstract: A method for processing various organic materials such as lignocellulosics or biomass into more useful states, such as charcoal, carbon black, and coke, and other processed products while producing useful off-gases, includes feeding aggregate pieces of the material to a vertically extending heating chamber and, preferably, closing the chamber to air to control oxygen therein. The pieces are conveyed upwardly through the chamber in a predetermined time by spiral vibratory conveyor. The chamber is heated to a preselected temperature sufficient for gaseous conversion of volatile hydrocarbon constituents of the material. Resultant off-gases are removed from the chamber for further use such as burning thereof for heating the chamber or condensing volatiles, etc.Apparatus for carrying out the method includes preferably first and second such chambers, there being continuous spiral vibrator tray in each chamber carried by a central, vertical support column.

Abstract: The apparatus includes a plurality of extruders which feed parallel streams or ribbons of raw material or charge along rollers through successive chambers in a kiln and through an annealing lehr to zones where the material is cut. The surfaces of the raw material are coated on three sides with a parting or releasing agent and, on the side to be exposed, with a glaze or engobe, or left uncoated.The firing chamber of the kiln has opposed rows of fuel burners on the sides directed toward ports on the other side and refractory rollers which protrude through the side walls and are supported on circumferentially spaced wheels. Wheels between adjacent ends synchronize rotation of the rollers. Manifolds feed the stack gases from the firing chamber into the preheating chamber.The process includes using charges which are either a mixture of a small amount of soluble carbonaceous material and water to adjust the carbon and moisture content of the clay or silica with carbonaceous material and water.

Abstract: A steel strip such as stainless steel is passed in uncoiled form through a jet recuperator, an intermediate furnace section, and a main fired furnace section in which a fuel such as natural gas is burned. The exit end of the main furnace section has an opening only slightly greater than the cross-section of the strip. The strip is preheated in the jet recuperator by forcing waste gases from top and bottom waste gas chambers through holes in the bottom and top, respectively, of the waste gas chambers against both sides of the strip. The strip is further heated by the waste gases in the unfired intermediate section and brought to final temperature in the main fired section.

Abstract: This invention provides a furnace system for and method of melting metal charges which utilizes hot gases generated by a burner, and are ordinarily discharged from the furnace as waste, for the dual purpose of preheating metal to be subsequently melted and preheating combustion air which is used to provide more efficient operation of the furnace burner.

Abstract: An improved arrangement for preheating a charge of raw material, illustratively an alloying charge, with hot gases prior to application of such charge to a ferroalloying kiln or other electric furnace is described. The charge to be preheated is loaded into a main vertically disposed reservoir which communicates at its bottom end with a combustion chamber adapted to generate the hot gases for preheating. A perforated transition cylinder is vertically disposed within the combustion chamber. Hot gases flow into the interior of the transition cylinder through the apertures and are directed upwardly through the charge stored in the main reservoir, thereby effecting the desired preheating action. The gases emerging from the top of the main reservoir enter a smoke chamber, from which they are discharged into suitable scrubbing and ventilating facilities. The preheated charge is selectively introduced into the electric furnace from the main reservoir via the transition cylinder.

Abstract: A joint between a rotary kiln and a tiltable hearth furnace, characterized in that a part of the hearth furnace embraces the discharge end of the rotary kiln and the pivotal axis of the hearth furnace coincides with the axis of rotation of the rotary kiln at the joint between the rotary kiln and the hearth furnace.

Abstract: A method and an apparatus for heating a granular aggregate for mixture with asphalt by means of a flue gas being chemically inert to the aggregate. The aggregate is moved intermittently within the gas under control of the stationary periods of driven screw conveyors. The apparatus has several heating sections, each section having a conveyor, a thermostat with a sensing device at the end of the section, and possibly also an oil burner, the thermostat being connected to the driving means of the conveyor.