Having Vertically Spaced Gas Supply Ports Patents (Class 432/99)
  • Patent number: 4747773
    Abstract: A vertical shaft kiln utilized in calcining limestone defines a series of processing zones including an upper preheating zone, a first calcining zone, a second calcining zone having a length twice that of the first calcining zone and a material cooling zone, Burners inject burnt gases intermediate the two calcining zones. Major heat transfer to the limestone is accomplished in the first calcining zone by directing a major portion of the burnt gases in counter-current to the material flow therethrough. Minor heat transfer is accomplished in the second calcining zone by directing a minor portion of the burnt gases therethrough in co-current relation with the material. Combustion air is provided through ducts in the material cooling zones and mixed with the minor portion of burnt gases externally of the shaft prior to injection into the burners.
    Type: Grant
    Filed: June 8, 1987
    Date of Patent: May 31, 1988
    Inventors: Lucian A. Predescu, Lucian D. Predescu
  • Patent number: 4740157
    Abstract: Solid materials are efficiently calcined in a single column kiln by effecting said calcination through a plurality of vertically arranged zones, by means of a method comprising the steps of feeding said solid materials to a preheating zone wherein the materials are preheated countercurrently with combustion gases, allowing said preheated materials to fall to an air preheating zone to which primary air is fed in parallel flow with said falling preheated materials, allowing said materials to fall to a calcining zone to which fuel is admitted in parallel flow with said preheated air, allowing the thus calcined materials to fall to a cooling zone to which secondary cold air is fed countercurrently with said falling materials, exhausting the combustion gases produced in the calcining zone together with said secondary air which was preheated by the calcined materials, at a point between said calcining and cooling zones, and feeding said combustion gases and secondary air as a mixture to the preheating zone.
    Type: Grant
    Filed: May 20, 1986
    Date of Patent: April 26, 1988
    Inventor: David D. D'Agrosa
  • Patent number: 4708640
    Abstract: The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part but is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6).
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: November 24, 1987
    Assignee: Outokumpu Oy
    Inventors: Matti E. Honkaniemi, Lauri A. Mustikka, Martti J. Jankkila, Pentti O. Hokkanen, Risto M. Heikkila, Launo L. Lilja
  • Patent number: 4705474
    Abstract: The present invention relates to a method and apparatus for preparing a feed mixture, made of several batch components, at one stage in order to feed it into a smelting furnace. The preparation of the batch may include the preheating and drying of the material, the removal of crystal waters and evaporable substances as well as the conduction of the batch into the smelting furnace. According to the invention, a hot inert gas is conducted through a downwards settling batch so that the gas is mixed into the batch as well as possible, but even partial fluidization is prevented. The apparatus of the invention comprises a pretreatment silo (6) which is uniform at the upper part is divided into several sub-silos (7) at the lower part. At the lower part of the sub-silos there are connected ducts (8) wherealong the batch flows into the smelting furnace (9) located below the pretreatment silo (6).
    Type: Grant
    Filed: July 28, 1986
    Date of Patent: November 10, 1987
    Assignee: Outokumpu Oy
    Inventors: Matti E. Honkaniemi, Lauri A. Mustikka, Martti J. Jankkila, Pentti O. Hokkanen, Risto M. Heikkila, Launo L. Lilja
  • Patent number: 4699588
    Abstract: An improved pulsating processing system for thermal, chemical, and physical processes which employs nonlongitudinal acoustic modes in a processing chamber to enhance the processing. An acoustically resonant processing chamber is provided as the processing vessel. A frequency tunable pulse combustor or other selectively variable frequency acoustic exciter is positioned to excite natural nonlongitudinal acoustic modes in the processing chamber. Material introduced into the processing chamber is thereby subjected to nonlongitudinal acoustic pulsations while the material is being processed. Also disclosed is an improved frequency and amplitude tunable pulse combustor which may be employed to excite the natural acoustic modes in the processing chamber. One disclosed embodiment is a system for drying a slurry of material such as kaolin. The nonlongitudinal acoustic excitations in the system result in improved moisture removal and particle heating.
    Type: Grant
    Filed: March 6, 1986
    Date of Patent: October 13, 1987
    Assignee: Sonotech, Inc.
    Inventors: Ben T. Zinn, Brady R. Daniel
  • Patent number: 4668184
    Abstract: An improved annular shaft kiln for burning particulate material such as limestone which adds a bridge to the lower part of the annular material zone between the burning zone and the cooling zone. This bridge permits heated cooling gas and at least some of the spent cooling gas to be withdrawn from the annular zone and be supplied directly to the combustion chamber of the kiln.
    Type: Grant
    Filed: July 8, 1986
    Date of Patent: May 26, 1987
    Assignee: Fuller Company
    Inventor: William D. Dorman
  • Patent number: 4662841
    Abstract: A method and apparatus is disclosed for burning and sintering alkaline materials such as limestone and dolomite in a shaft furnace wherein the alkaline material travels successively through a preheating, burning and cooling area. At the upper end of the cooling area the cooling air traversing the shaft from bottom to top is aspirated into a recuperator wherein fresh combustion air is preheated by the cooling air and then supplied to the burner which heats the burning area. Part of the aspirated cooling air may also be directed past the recuperator through a bypass conduit to heat a dryer which dries the materials to be processed by the shaft furnace.
    Type: Grant
    Filed: October 30, 1985
    Date of Patent: May 5, 1987
    Inventor: Peter Zeisel
  • Patent number: 4619606
    Abstract: A vertical maltdrying kiln is described whereby several flow zones for the drying air are provided within a vertical malt compartment. At least in the uppermost flow zone at least one airduct with perforated sidewalls is provided, which extends in the transverse direction through the malt compartment. In the uppermost flow zone, the drying air enters through this airduct and optionally through perforated sidewalls in the transverse direction, while it escapes in the upward direction. Preferrably, a lower malt discharge lock is perforated, so that drying air may enter into the lowermost flow zone. This drying air may escape through perforated sidewalls or through airducts with perforated sidewalls. Preferrably, the entire drying air of all flow zones may escape in the upward direction through the upper open end of the malt compartment.
    Type: Grant
    Filed: February 7, 1985
    Date of Patent: October 28, 1986
    Inventor: Christian K. Numberger
  • Patent number: 4473352
    Abstract: In a double-incline shaft kiln in which ore materials are charged into the furnace from the top of a vertical external portion of the shaft and are calcined by burners installed in the lower portion of the shaft, the calcining zone is effectively extended by the provision of an injector which causes the hot gas to flow in the lower portion of the shaft parallel to the flow of ore materials. Further, at the turnover locations for the ore descending through the shaft, the width of the shaft is broken into at least two portions which promotes a more even velocity of the material flow across the width of the shaft so as to enable combustion control and the prevention of the ash of solid fuel, such as coal, from mixing with the calcined material to cause discoloration and lumps.
    Type: Grant
    Filed: October 15, 1982
    Date of Patent: September 25, 1984
    Assignee: Nippon Lime, Ltd.
    Inventors: Hiraku Sonoda, Setsuo Tamura
  • Patent number: 4452584
    Abstract: A method and improved kiln for calcining and sintering of lumpy materials which includes an arrangement for creating a cavity in the material being processed adjacent each burner units so that a solid fuel can be applied on a cavity surface of the material at each burner.
    Type: Grant
    Filed: March 12, 1982
    Date of Patent: June 5, 1984
    Inventors: Ulrich Beckenbach, Helmuth Beckenbach
  • Patent number: 4431407
    Abstract: A process for burning and sintering material in lump form in a shaft furnace in which part of the cooling air flowing in a counterflow through the cooling zone is removed from the shaft furnace before the upper end of the cooling zone and is introduced into the column of material in the burning zone area, accompanied by a mixture of air and fuel. As a result a reducing furnace atmosphere is obtained, which extends up to the plane of the upper combustion chambers. The invention also relates to an annular shaft furnace for performing this process.
    Type: Grant
    Filed: December 24, 1981
    Date of Patent: February 14, 1984
    Inventors: Ulrich Beckenbach, Helmuth Beckenbach
  • Patent number: 4403951
    Abstract: A shaft furnace for burning or firing and sintering material, such as limestone, dolomite, etc in lump or pellet form, in which the cooling air is introduced into the external cooling air duct in the vicinity of the furnace bottom, flows upwardly through duct the air duct and downwards through an internal cooling air duct and then passes from an air outlet of internal cooling air duct positioned in the vicinity of the furnace bottom into a first bustle pipe or the like surrounding the shaft furnace. A combustion air duct is supplied with combustion air from a first bustle pipe. A fuel gas supply line runs within the external cooling air duct.
    Type: Grant
    Filed: December 24, 1981
    Date of Patent: September 13, 1983
    Inventors: Ulrich Beckenbach, Helmuth Beckenbach
  • Patent number: 4389979
    Abstract: A method and apparatus for the operation of a stoker-fired boiler having a boiler arranged coaxially adjacent to a stoker chamber. The cross-sectional area of the connection between the stoker and the boiler is constricted, preferably in the range of one-third to one-fourth of the cross-sectional area of the stoker chamber, so that the flammable gases flowing from the stoker to the boiler are accelerated and generate a reduced pressure at the constricted connection. Tertiary air is introduced at the circumference of the constricted connection at an increased pressure, to thereby induce more complete combustion of the gases. The area of flow flares out as the gas enters the boiler. In the preferred arrangement, guide means control the introduction of the tertiary air through an annular gap at the constricted connection The stoker also preferably includes rings of nozzles arranged at selected angles to introduce secondary air into the stoker chamber.
    Type: Grant
    Filed: May 1, 1981
    Date of Patent: June 28, 1983
    Inventor: Oddmund Saxlund
  • Patent number: 4352661
    Abstract: Air heated outside the calcining zone of a shaft kiln is passed through raw material in a hopper mounted above the kiln in order to preheat the raw material. In one embodiment the preheating air is heated by an excess air burner which communicates with the hopper. In another embodiment, the hot calcined material is cooled by forcing cool air through it and the heated air is utilized as preheating air by directing it through a by-pass conduit which connects the cooling zone of the kiln with an extension of the hopper. In neither embodiment does the preheating air constitute combustion supporting air.
    Type: Grant
    Filed: February 6, 1981
    Date of Patent: October 5, 1982
    Assignee: A. P. Green Refractories Co.
    Inventors: James A. Crookston, James L. Hill
  • Patent number: 4334859
    Abstract: A method and apparatus for economically melting matrix materials, said apparatus comprising a drier, a vertical furnace including a unique arrangement of refractory bars and a rotary kiln and the method including passing the solid matrix material first through a dryer which is heated by the waste gas of a vertical furnace, then to the top of the vertical furnace where it is melted by direct flame contact and thereafter cascading the melted material downwardly through said arrangement of refractory bars as the exhaust from a rotary kiln is blown upwardly through the vertical furnace with the melted material finally flowing from the bottom of the furnace into a rotary kiln where it is further heated and mixed prior to discharge.
    Type: Grant
    Filed: July 20, 1978
    Date of Patent: June 15, 1982
    Inventors: Susumu Minegishi, Mikio Minegishi
  • Patent number: 4291634
    Abstract: Apparatus for disposing of pelletized refuse by conversion into useful gaseous products and inert solid residue, comprising a vertical shaft and an enlarged hearth beneath the shaft, with a multiplicity of tuyeres for feeding oxygen-containing gas into the hearth.
    Type: Grant
    Filed: May 29, 1980
    Date of Patent: September 29, 1981
    Assignee: Union Carbide Corporation
    Inventors: Victor E. Bergsten, Edward P. Eardley, Thomas G. Halvorson
  • Patent number: 4287160
    Abstract: Process for the burning of lime, cement or other lumpy bulk materials in a shaft kiln using coal. Coal dust or particulated dry coal is continuously fed into a gasification chamber positioned in the center of the shaft kiln and is therein partially or fully gasified by the addition of air in substoichiometric proportions. The partially or fully gasified fuel is mixed with air at an elevated temperature. Such mixture is then burned in the burning zone of the shaft kiln. The flow of the heating medium, i.e., the burnt fuel, and the flow of the kiln charge are co-current within the kiln. The shaft kiln has a centrally postioned gasification chamber which is mounted on radial supports which are positioned in the shaft kiln in such a way as to produce a space below the supports. The space is substantially free from kiln charge. Uniform distribution of the gases is guaranteed across the cross section of the shaft kiln by the space.
    Type: Grant
    Filed: August 9, 1979
    Date of Patent: September 1, 1981
    Assignee: Johann Schaefer Kalkwerke
    Inventor: Hans von Zander
  • Patent number: 4252521
    Abstract: A furnace is disclosed for the heat treatment of mainly lumpy to fine grained material. The furnace is either a shaft furnace or a rotary furnace for the calcination or sintering of limestone, dolomite or magnesite. The calcination material passes through a preheating zone, a calcination zone and a cooling zone. The calcination zone has a gas feed and gas withdrawal device. A calcination device is provided in the calcination zone to which is connected a gas conveying device for the production of a hot gas circulation. The hot gas circulation device is situated between the gas withdrawal device and the calcination device and is provided as a conveying blower subjected to a cooling liquid.
    Type: Grant
    Filed: January 15, 1979
    Date of Patent: February 24, 1981
    Assignee: Klockner-Humboldt-Deutz AG
    Inventor: Heinrich Buchner
  • Patent number: 4249891
    Abstract: A continuous grain drying and conditioning apparatus of a type including a burner and blower, or a multiplicity of burners and blowers, surrounded by a plenum chamber, air pervious grain holding walls positioned outwardly with respect to the plenum chamber is characterized by having a plenum divider which is selectively adjustable in position to divide the grain holding walls into a heating section and a cooling section. A multiplicity of grain turning apparatus of full and partial width of the grain column is disposed in the grain column for separating the grain mass into two or more separate divisions and then turning the cooler-wetter grain inwardly as it moves downwardly and turning the hotter-dryer grain outwardly as it moves downwardly in the grain column. Grain is constantly removed from the bottom of the apparatus at a rate governed by the average temperature of the air exiting the grain at a point adjacent the position of the plenum divider and a point closer to the input of the grain.
    Type: Grant
    Filed: September 14, 1978
    Date of Patent: February 10, 1981
    Assignee: Beard Industries, Inc.
    Inventors: Ronald T. Noyes, Eugene E. Williams
  • Patent number: 4221560
    Abstract: The present invention provides an apparatus for the regeneration of wet spent active carbon devised so as to bring the active carbon supplied from a hopper into contact with a reaction gas generated or heated to high temperature in a furnace, wherein an exhaust duct for the high-temperature exhaust gas from the furnace is installed penetrating the hopper in order to heat the active carbon descending therein and a condensate collecting header for discharging water separated from the active carbon is disposed at the lower part of the hopper.
    Type: Grant
    Filed: October 10, 1978
    Date of Patent: September 9, 1980
    Assignees: JGC Corporation, Takeda Chemical Industries, Ltd.
    Inventors: Hideji Idei, Mitsuhiko Iwasaki, Michio Ito, Toshimichi Hirabayashi, Zenji Matsumoto, Nobutaka Ninomiya
  • Patent number: 4205459
    Abstract: In regenerating an adsorbent by eliminating water and an adsorbed matter which are contained therein, the adsorbent is indirectly heated while descending within a drying furnace and is indirectly heated while ascending within a regenerating furnace in order to prevent the adsorbent from scattering due to water vapor and the adsorbed gas separated by the heating of the adsorbent and to prevent the adsorbent from burning itself due to heat.
    Type: Grant
    Filed: March 8, 1978
    Date of Patent: June 3, 1980
    Assignees: Hitachi, Ltd., Hitachi Chemical Co.
    Inventors: Yasuo Koseki, Toyohiko Kaneko, Masayoshi Kubota, Sankichi Takahashi
  • Patent number: 4172328
    Abstract: Apparatus for contacting a packed bed of particulate material with a treating gas includes a downwardly converging bin, hot gas distributors and a cooling gas distributor. The method whereby the apparatus is used as a reactor dryer to treat particulate sponge iron is also disclosed.
    Type: Grant
    Filed: March 6, 1978
    Date of Patent: October 30, 1979
    Assignee: Midrex Corporation
    Inventors: Robert M. Escott, Winston L. Tennies, Gilbert Y. Whitten, Jr.
  • Patent number: 4165216
    Abstract: This invention comprises an apparatus and process for drying and/or heating materials. This invention was designed for use in the production of charcoal from wood feed material; however, it can be used to heat and/or dry many types of materials. Feed material is disposed in a reactor, wherein there is provided a first array of input channels extending through said feed material, through which hot gases are introduced into said feed material, and a second array of output channels extending through said feed material to collect and exit those hot gases and any gases or vapors derived from the heating and/or drying of the feed material.
    Type: Grant
    Filed: March 23, 1977
    Date of Patent: August 21, 1979
    Assignee: Enerco, Inc.
    Inventors: Eugene W. White, Francis M. Gross, Fred E. Knoffsinger
  • Patent number: 4147504
    Abstract: The regenerating apparatus or furnace has gas burners mounted thereon to deliver combustion gas tangentially to a header and thence to distributing ports arranged circumferentially around and internally of a columnar bed of carbon being regenerated to provide uniform temperature distribution across the bed. In an alternate construction, the columnar bed is annular, headers are provided exteriorly and interiorly of the bed, and distribution ports conduct the combustion gas through the inner and outer walls defining the annular bed.
    Type: Grant
    Filed: February 16, 1977
    Date of Patent: April 3, 1979
    Assignee: Unitika Limited
    Inventors: Kiyoshi Akae, Masaya Kitada, Yoshiyuki Uno
  • Patent number: 4120644
    Abstract: The present invention provides a double-cylinder type apparatus for the regeneration of active carbon, which comprises a heating furnace provided with at least one burner and at least one annular regeneration chamber composed of at least one set of an inner cylinder and an outer cylinder installed concentrically inside said heating furnace, said outer cylinder having a plurality of holes penetrating the side wall thereof, wherein the spent active carbon is supplied to the upper part of said annular regeneration chamber and the regenerated carbon is to be taken out at the lower part of the same. The heating of said annular regeneration chamber from the side of said inner cylinder is performed either by introducing the flue gas arising in said heating furnace into the inner cylinder or by providing at least one burner within said inner cylinder and utilizing the combustion gas from said burner.
    Type: Grant
    Filed: March 23, 1977
    Date of Patent: October 17, 1978
    Assignees: JGC Corporation, Takeda Chemical Industries, Ltd.
    Inventors: Kouichi Numasaki, Yoshihisa Sakai, Takehiko Nawa, Zenji Matsumoto, Nobutaka Ninomiya
  • Patent number: 4083679
    Abstract: An installation for the burning and/or sintering and cooling of cement clinker, lime, magnesite, dolomite and similar materials in granular or crushed form, especially adapted as a small-scale cement mill or lime mill, having two movable materials carrying platforms arranged inside a burn chamber, in a staggered relationship, and an intermediate wall subdividing the burn chamber into a forehearth for the upper platform and a main hearth for the lower platform. Blowers supply combustion air, draw the used burn gases through air permeable back walls above the platform, recirculate them into the changing shaft to dry and preheat the materials, and cool the sintered materials in the cooling shaft. An aftersinter platform or rotating aftersinter kiln may be arranged between the lower platform and the cooling shaft.
    Type: Grant
    Filed: January 17, 1977
    Date of Patent: April 11, 1978
    Assignee: Readymix Cement Engineering GmbH & Co. KG
    Inventor: Erich Bade
  • Patent number: 4054409
    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.
    Type: Grant
    Filed: May 12, 1976
    Date of Patent: October 18, 1977
    Assignee: Nippon Kokan Kabushiki Kaisha
    Inventors: Ryo Ando, Kazuo Sano, Takao Miyazaki
  • Patent number: 4030876
    Abstract: A method in which activated carbon having a bulk density of at least 0.35, a particle size of 5 to 40 mesh and a water content of 50 to 120% is regenerated by being passed successively through drying, burning and reviving treatment zones of a vertical columnar furnace, which zones are maintained within temperature gradients such as to prevent explosion and oxidation or destruction of the carbon due to overheating while the carbon descends through the zones and is heated by a high temperature combustion gas flowing upwardly through the treatment zones at a rate not exceeding the minimum rate of fluidization of the descending carbon.The regenerating apparatus or furnace has gas burners mounted thereon to deliver combustion gas tangentially to a header and then to distributing ports arranged circumferentially around and internally of a columnar bed of carbon being regenerated to provide uniform temperature distribution across the bed.
    Type: Grant
    Filed: June 10, 1975
    Date of Patent: June 21, 1977
    Assignee: Unitika Ltd.
    Inventors: Kiyoshi Akae, Masaya Kitada, Yoshiyuki Uno
  • Patent number: 4008994
    Abstract: The present invention provides an apparatus, and a method for the regeneration of spent wet active carbon, which apparatus comprises a drier for substantially drying the spent carbon, a heating furnace provided with at least one burner and at least one duct, and a regeneration chamber consisting of at least one set of inner cylinder and outer cylinder installed concentrically and vertically inside said heating furnace to penetrate the top and bottom walls of the furnace, wherein said inner and outer cylinders have respectively a multiplicity of holes penetrating the side walls thereof, said inner cylinder is connected with a supply tube for a regeneration gas capable of effecting regeneration of the dried carbon-to-be-regenerated upon contact therewith, the upper end of said outer cylinder is connected with said drier so as to receive said dried carbon therefrom while the lower end thereof forms an outlet for the regenerated carbon, and said duct is connected with the drier so as to facilitate direct or indir
    Type: Grant
    Filed: May 8, 1975
    Date of Patent: February 22, 1977
    Assignees: Japan Gasoline Co., Ltd., Takeda Chemical Industries, Ltd.
    Inventors: Kouichi Numasaki, Nobutaka Ninomiya, Zenji Matsumoto, Kiyoshi Adachi, Toyohisa Fujimoto
  • Patent number: 4002422
    Abstract: Apparatus for treating particulate material with hot gases wherein preheated gases are introduced to the particulate material to heat and treat such material and a second cooler gas is introduced to the heated material to impart some cooling to the material and to heat the second gas to treatment temperature followed by movement of the heated second gas through the bed of material in which it acts in the same manner as the hot treating gas.
    Type: Grant
    Filed: September 22, 1975
    Date of Patent: January 11, 1977
    Assignee: Midrex Corporation
    Inventor: Robert Milton Escott
  • Patent number: 3958919
    Abstract: In a method for melting a material in a vertical shaft furnace having an upper portion, a lower combustion zone portion and an intermediate post-burning portion, said upper and lower portions being separated by a restriction and wherein coke is burned and the material melted in said lower combustion zone by introducing a blast of air close to the bottom of the lower combustion zone to produce combustion gases containing CO and/or H.sub.
    Type: Grant
    Filed: June 10, 1974
    Date of Patent: May 25, 1976
    Assignee: Rockwool Aktiebolaget
    Inventor: Sven Olof Kjell Kjell-Berger
  • Patent number: 3957422
    Abstract: The device and method of the invention embodies a shaft furnace containing no constrictions in the cross section of the shaft furnace that would unfavorably affect the movement characteristics in the filling. The arrangement of the pipes of the burning system in rings composed of closed arcuate pipe segments, adapted to the shape of the shaft furnace cross section and the provision of such pipes with a multiplicity of discharge openings for the fuel and the air of combustion which are uniformly distributed in intimate proximity to each other of horizontal rows of air and fuel pipes over the furnace periphery.According to the invention it is also feasible to arrange, in dependency on the furnace height and the material to be heat-treated, several pairs of ring pipe lines for fuel and air of combustion, either directly on top of each other in close proximity or in different combustion planes.
    Type: Grant
    Filed: January 23, 1975
    Date of Patent: May 18, 1976
    Inventor: Georg Bernhard Kohn
  • Patent number: 3941557
    Abstract: A calcining method and apparatus are provided wherein material to be treated is fed into the top of the furnace and the finished material discharges from the bottom of the furnace and cooling and combustion air enters under forced draft through the bottom of the furnace and flows upwardly through the column of material. A part of the fuel supply is delivered to the region between an upper preheating zone in the furnace and a subjacent combustion or firing zone and the balance of fuel required for firing is introduced into the combustion zone about its periphery. Provision is also made for bypassing part of the cooling air from a lower cooling zone to the combustion zone, with intermediate cleaning of the bypassed air.
    Type: Grant
    Filed: December 23, 1974
    Date of Patent: March 2, 1976
    Assignee: Klockner-Humboldt-Deutz Aktiengesellschaft
    Inventor: Heinrich Buchner