Patents by Inventor Ernst Luhrsen

Ernst Luhrsen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5942316
    Abstract: The invention concerns a multi-layer refractory wear body having a wear layer being exposed to a direct thermal, mechanical and/or metallurgical attack, and at least another layer of a ceramic material having different physical properties.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: August 24, 1999
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Andreas Schuler, Robert Sheriff, Martin Wiesel
  • Patent number: 5657997
    Abstract: A fixing device for a ceramic sealing plate in a carrying frame or cassette of a seal on a metallurgical vessel has the sealing plate held by a band on the carrying frame or the cassette. To press the sealing plate evenly along its perimeter, the band is corrugated in its longitudinal direction. One set of ridges of the band lies elastically on the sealing plate. The ridges lying between the one set lie elastically on the carrying frame or on the cassette, or on a spacer sheet between the band and the carrying frame of the cassette.
    Type: Grant
    Filed: May 3, 1995
    Date of Patent: August 19, 1997
    Assignee: Didier-Werke AG
    Inventor: Ernst Luhrsen
  • Patent number: 5429283
    Abstract: An immersion nozzle is employed for discharging material from a vessel to a mold and includes an upper section to be connected to the vessel and a lower section having a region to be immersed in material in the mold. The upper and lower sections have extending therethrough respective discharge channels that communicate and that enable material to be discharged from the vessel to the mold. The discharge channel of the upper section converges downwardly in a first vertical plane to join the discharge channel of the lower section. The discharge channel of the upper section also expands downwardly in a second vertical plane transverse to the first vertical plane to join the discharge channel of the lower section. Each of the upper and lower sections is formed by at least one respective separate member. The members have adjacent ends having mutually facing and fitting surfaces, and each pair of facing and fitting end surfaces has therebetween a seal.
    Type: Grant
    Filed: May 31, 1994
    Date of Patent: July 4, 1995
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Siegfried Pohl, Karl Baum, Erich Galle
  • Patent number: 5413744
    Abstract: A process for heating a ceramic shaped part by providing a ceramic shaped part which at ambient temperature has a homogeneously distributed carbon skeleton, and heating the shaped part inductively.
    Type: Grant
    Filed: October 13, 1993
    Date of Patent: May 9, 1995
    Assignee: Didier-Werke AG
    Inventors: Raimund Bruckner, Ullrich Hintzen, Ernst Luhrsen, Hans Rothfuss, Albert Ott
  • Patent number: 5303905
    Abstract: A refractory ceramic stopper has therein a recess including an annular outwardly enlarged portion defining a stop surface. A stopper rod inserted into the recess in the stopper has a support surface. A plurality of spreadable members having opposite ends are positioned about the stopper rod and are inserted therewith into the recess in the stopper. The spreadable members are spread outwardly such that they enter the enlarged portion of the recess in the stopper with first ends of the spreadable members confronting the stop surface of the stopper and with second ends of the spreadable members confronting the support surface of the stopper rod. Thereby the spreadable members lock the stopper onto the stopper rod.
    Type: Grant
    Filed: September 23, 1992
    Date of Patent: April 19, 1994
    Assignee: Didier-Werke AG
    Inventors: Siegfried Pohl, Dirk Masurat, Ernst Luhrsen, Gerd Bohndorf
  • Patent number: 5190716
    Abstract: A ceramic part to be used in a high temperature environment and that is preheated prior to use is manufactured by a process including shaping the part and subjecting the part to a heat treatment operation. The heat treatment operation is performed at least partially on location at a position of use of the part in the high temperature environment by a heating device that also is operated to perform the preheating of the part.
    Type: Grant
    Filed: November 19, 1991
    Date of Patent: March 2, 1993
    Assignee: Didier-Werke AG
    Inventors: Raimund Bruckner, Hans Rothfuss, Albert Ott, Ernst Luhrsen
  • Patent number: 5173199
    Abstract: An apparatus is disclosed for use in replacing a worn pouring pipe by moving a pouring pipe from a waiting position to a pouring position beneath a discharge opening of a metallurgical vessel, and for use in adjusting flow of molten metal from the metallurgical vessel through the discharge opening. For this purpose, slide rails are provided beneath the metallurgical vessel for supporting head plates of pouring pipe in the waiting position, the pouring position and a discharge position. Also, a linear actuator is provided for pushing the pouring pipe from the waiting position to the pouring position, and can be detachably coupled to the head plate of the pouring pipe so that it can move the pouring pipe in opposing direction to adjust the flow of molten metal through the discharge opening between zero flow and full flow.
    Type: Grant
    Filed: July 24, 1991
    Date of Patent: December 22, 1992
    Assignee: Didier-Werke AG
    Inventors: Raimund Bruckner, Ernst Luhrsen, Hans Rothfuss, Ullrich Hintzen, Peter Keutgen
  • Patent number: 5173242
    Abstract: An assembly includes a discharge member of a metallurgical vessel and a pipe member connected to the discharge member at mutual surfaces thereof defining a seat therebetween. An annular recess is formed in the region of such seat, a seal seals such seat, and gas is supplied to the annular recess. The seal is in the form of a pair of compressible sealing rings positioned between the mutual surfaces of the two members on opposite sides of the annular recess. A pressure indicator is connected to a gas supply line supplying gas to the annular recess to provide an indication of the pressure of gas prevailing in the annular recess, and particularly of changes of such pressure.
    Type: Grant
    Filed: July 30, 1991
    Date of Patent: December 22, 1992
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Ulrich Schneider
  • Patent number: 5171495
    Abstract: A refractory immersion nozzle which can be used for processing metal melts, and a process for producing the nozzle by providing a mixture containing alumina having a maximum grain size of 250 microns, an aggregate having less tendency than alumina to form incrustations during use of the nozzle, boron nitride, a fluxing agent, a bonding agent and a mixing liquid, molding the mixture to form a shaped body, and drying the shaped body. The nozzle inhibits accretion of slag constituents from the metal melts, and has sufficiently good spalling resistance.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: December 15, 1992
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Albert Ott
  • Patent number: 5106060
    Abstract: A closing and/or regulating apparatus for tapping molten metal from the interior of the metallurgical vessel includes an inner refractory pipe having extending through a wall thereof at least one opening and an outer refractory pipe fitted over the inner pipe and having extending through a wall thereof at least one opening. Outer and inner surfaces of the inner and outer pipes, respectively, define mating sealing surfaces. One of the pipes is fixedly mounted to a metallurgical vessel, and the other pipe is movable axially and/or rotatably relative to the one pipe to thereby selectively bring the openings to the two pipes relatively into and out of alignment. The inner pipe has adjacent an inner end thereof at a position inwardly of the opening therein a closure closing the interior of the inner pipe. The outer pipe defines therein a space forming a gas distribution chamber at a location confronting the closure.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: April 21, 1992
    Assignee: Didier-Werke AG
    Inventors: Ullrich Hintzen, Ernst Luhrsen, Andreas Schuler
  • Patent number: 5092500
    Abstract: A refractory discharge device includes an immersion nozzle formed substantially of carbon-bonded magnesium oxide or carbon-bonded aluminum oxide or fused quartz. The immersion nozzle has therethrough a discharge passage and has an outer surface and an outlet end. An external reinforcement member is formed entirely separately from the immersion nozzle from a zirconium oxide material that is directly bonded without any carbon and by burning at a high temperature. The external reinforcement member is attached to the outer surface of the outer surface of the immersion nozzle at a position such that during use the external reinforcement member will extend above and below a casting powder covering of molten metal into which the refractory discharge device will be immersed.
    Type: Grant
    Filed: February 7, 1991
    Date of Patent: March 3, 1992
    Assignee: Didier-Werke AG
    Inventors: Udo Weber, Ernst Luhrsen, Albert Ott, Steve Lee
  • Patent number: 5083688
    Abstract: A rotary valve for controlling the discharge of molten metal in a substantially downward direction from a metallurgical vessel includes a refractory rotor rotatable about a substantially horizontal axis. The rotor has an outer peripheral surface, either conical or cylindrical, arranged symmetrically about the axis, and the rotor has therethrough a flow channel having inlet and outer ports, at least the outlet port opening onto the outer surface. A refractory stator has therein a recess defined by an inner surface, either conical or cylindrical, complementary to the outer surface of the rotor, the stator having therethrough a discharge channel. The rotor fits within the recess in the stator, with the outer and inner surfaces thereof being complementarily positioned symmetrically about the axis.
    Type: Grant
    Filed: December 21, 1989
    Date of Patent: January 28, 1992
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Ullrich Hintzen, Raimund Bruckner
  • Patent number: 5080265
    Abstract: A closing and/or regulating apparatus for tapping molten metal from the interior or a metallurgical vessel includes a vertical inner pipe having extending through a wall thereof at least one opening for the passage of molten metal. An outer pipe is fitted over the inner pipe and has extending through a wall thereof at least one opening. One of the pipes is to be mounted stationarily with respect to a metallurgical vessel, and the other of the pipes is displaceable relative to such one pipe in a vertical axial direction through a working stroke at which the openings of the pipes may be brought into alignment to thereby discharge molten metal downwardly through the interior of the inner pipe. The dimension of the opening in the stationary pipe in such direction is greater than the dimension of the opening in the displaceable pipe in such direction.
    Type: Grant
    Filed: October 17, 1990
    Date of Patent: January 14, 1992
    Assignee: Didier-Werke AG
    Inventors: Ullrich Hintzen, Ernst Luhrsen, Andreas Schuler
  • Patent number: 5072864
    Abstract: Disclosed are wearable carbon-containing refractory elements, such as wearable refractory parts of a slide valve for use in controlling flow of molten metal from a metallurgical vessel, which are impregnated with tar or other wear reducing agent. In order to prevent decarburization of the refractory elements, they are saturated in an aqueous borate solution and then dried, so that the borate will migrate outwardly toward the surfaces of the elements and form protective layers which will prevent infiltration of ambient air into the refractory material. Prior to saturation of the elements in the borate solution, the wearable surfaces of the elements, such as those surfaces which will be subject to contact with molten metal, are coated with film which will prevent saturation by the borate solution, such that no protective layer is formed at the wearable surfaces. This allows the tar or other wear reducing agent to migrate outwardly through the wearable surfaces so as to reduce wear caused by the molten metal.
    Type: Grant
    Filed: September 14, 1990
    Date of Patent: December 17, 1991
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Andreas Schuler, Ullrich Hintzen
  • Patent number: 5058784
    Abstract: A closing and/or regulating apparatus for tapping molten metal from the interior of the metallurgical vessel includes an inner refractory pipe having extending through a wall thereof at least one opening and an outer refractory pipe fitted over the inner pipe and having extending through a wall thereof at least one opening. Outer and inner surfaces of the inner and outer pipes, respectively, define mating sealing surfaces. One of the pipes is fixedly mounted to a metallurgical vessel, and the other pipe is movable axially and/or rotatably relative to the one pipe to thereby selectively bring the openings to the two pipes relatively into and out of alignment. The inner pipe has adjacent an inner end thereof at a position inwardly of the opening therein a closure closing the interior of the inner pipe. The outer pipe defines therein a space forming a gas distribution chamber at a location confronting the closure.
    Type: Grant
    Filed: October 17, 1990
    Date of Patent: October 22, 1991
    Assignee: Didier-Werke AG
    Inventors: Ulrich Hintzen, Ernst Luhrsen, Andreas Schuler
  • Patent number: 5037017
    Abstract: A rotary valve for controlling the discharge of molten metal from a metallurgical vessel includes a refractory rotor having a cylindrical outer peripheral surface and fitted within a recess defined by a cylindrical inner surface in a refractory stator and complementary to the outer surface. The rotor may be rotated about either a horizontal or a vertical axis relative to the stator and may be axially moved within the recess therein. The rotary valve may be mounted on the exterior of a bottom wall of a metallurgical vessel or alternatively may be mounted within a refractory lining of the metallurgical vessel, particularly in a transition area between a side wall and a bottom wall of the metallurigcal vessel. Further alternatively, the rotary valve may be mounted within the refractory lining of the bottom wall of the metallurgical vessel, with the rotor extending through the bottom wall and being actuated for movement from below the bottom wall.
    Type: Grant
    Filed: October 13, 1989
    Date of Patent: August 6, 1991
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Ullrich Hintzen, Raimund Bruckner
  • Patent number: 5025961
    Abstract: A refractory shutoff assembly for controlling the discharge of molten metal from a metallurgical vessel includes a refractory inner pipe to be fixedly mounted in a bottom of the vessel, such inner pipe having therethrough at least one opening at a position to be above the vessel bottom. A refractory outer pipe is mounted about the inner pipe and has therethrough at least one opening. The outer pipe has a lower end with an annular end surface. The outer pipe is movable relative to the inner pipe axially thereof between an open position, whereat the opening in the outer pipe aligns with the opening in the inner pipe, and a closed position, whereat such openings are isolated to block molten metal discharge.
    Type: Grant
    Filed: August 13, 1990
    Date of Patent: June 25, 1991
    Assignee: Didier-Werke AG
    Inventors: Ullrich Hintzen, Ernst Luhrsen, Andreas Schuler
  • Patent number: 4994216
    Abstract: A process of making carbon-bonded refractory shapes by preparing a mix of refractory materials, pitch or tar and a binder resin, molding the mix into shapes and hardening the shapes. A starting mix is used which, based on the added quantity by weight of pitch or tar, contains 1 to 10 weight % of hollow fibers. The refractory shapes have the advantage that they exhibit less cracking, and hardly any, or even no, breaking occurs during their fabrication.
    Type: Grant
    Filed: October 20, 1988
    Date of Patent: February 19, 1991
    Assignee: Didier-Werke AG
    Inventors: Ullrich Hintzen, Heinz Schermer, Ernst Luhrsen
  • Patent number: 4949886
    Abstract: A rotary valve for controlling the discharge of molten metal from a metallurgical vessel includes a refractory rotor having a cylindrical outer peripheral surface and fitted within a recess defined by a cylindrical inner surface in a refractory stator and complementary to the outer surface. The rotor may be rotated about either a horizontal or a vertical axis relative to the stator and may be axially moved within the recess therein. The rotary valve may be mounted on the exterior of a bottom wall of a metallurgical vessel or alternatively may be mounted within a refractory lining of the metallurgical vessel, particularly in a transition area between a side wall and a bottom wall of the metallurgical vessel. Further alternatively, the rotary valve may be mounted within the refractory lining of the bottom wall of the metallurgical vessel, with the rotor extending through the bottom wall and being actuated for movement from below the bottom wall.
    Type: Grant
    Filed: September 19, 1988
    Date of Patent: August 21, 1990
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Ullrich Hintzen, Raimund Bruckner
  • Patent number: 4923225
    Abstract: A member formed of ceramic refractory material has therein an opening. A metal coupling member for attaching a metal member such as a rod or a tube, to the refractory member has an externally threaded portion extending into the opening in the refractory member. The coupling member has a head extending radially outwardly beyond the threads of the threaded portion and embedded in the refractory member. The opening in the refractory member may be internally threaded to receive the threads of the threaded portion of the coupling member.
    Type: Grant
    Filed: September 27, 1988
    Date of Patent: May 8, 1990
    Assignee: Didier-Werke AG
    Inventors: Ernst Luhrsen, Siegfried Pohl, Albert Ott, Wilhelm Parbel, Karl Baum