Patents by Inventor Yih-Wan Tsai

Yih-Wan Tsai 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: 5893940
    Abstract: A method of controlling NO.sub.x emissions from a glass melting process in which combustion fuel produces exhaust gas in a melting furnace including NO.sub.x compounds is disclosed. Furnace exhaust gas passes from the melting furnace through a regenerator to a zone downstream from the regenerator. Ammonia is injected into the furnace exhaust gas at the downstream zone while the furnace exhaust gas is within a desired temperature range to reduce the amount of NO.sub.x compounds. Additional gas is introduced into the furnace exhaust gas as it moves from the regenerator to the downstream zone whenever the furnace exhaust gas has a temperature which is outside the desired temperature range at the downstream zone so as to modify the furnace exhaust gas temperature such that the furnace exhaust gas is within the desired temperature range when furnace exhaust gas reaches to the downstream zone.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: April 13, 1999
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 5840093
    Abstract: The instant invention provides a method of controlling the accumulation of sodium sulfate in the checker packing of a regenerator of a cross-fired regenerative-type glass melting furnace. Typically, glass batch materials are melted within the furnace by combustion of fuel. This combustion produces exhaust gas that is drawn through the regenerator and heats the checker packing. During the melting operation, sodium sulfate gas is formed by the melted glass and is carried with the exhaust gas through the regenerator. The sodium sulfate gas may condense on a portion of the checker packing. As the sodium sulfate condensate accumulates on the checker packing, it may restrict the flow of exhaust gas and/or combustion air through the regenerator.
    Type: Grant
    Filed: December 6, 1996
    Date of Patent: November 24, 1998
    Assignee: PPG Industries, Inc.
    Inventors: Yih-Wan Tsai, Walter W. Scott
  • Patent number: 5795363
    Abstract: The present invention provides an apparatus and method for reducing the occurrences of solid defects in float glass due to corrosion of refractory in a glass melting and refining furnace. In making flat glass by the float process, batch materials are fed into a melting and refining furnace and heated to form molten glass. The molten glass passes through the melting section and into a refining section of the furnace where the glass is gradually cooled and conditioned prior to delivering the glass to a forming chamber where the molten glass is floated upon molten metal and formed into a continuous sheet of glass. During the melting operation, alkali vapors from the molten glass accumulate within a downstream portion of the melting section. These vapors attack and corrode those portions of the melting section of the furnace which are constructed from silica refractory. The products of the corrosion are deposited in the molten glass resulting in solid defects.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: August 18, 1998
    Assignee: PPG Industries, Inc.
    Inventors: George A. Pecoraro, Yih-Wan Tsai
  • Patent number: 4816056
    Abstract: In a method of making glass or the like, wherein the batch materials are liquefied in a distinct zone from the refiner, the liquefied material is heated in an intermediate stage before being fed to the refiner. The heating entails intensified flames that impinge the surface to provide homogenization and a barrier to surface flow of low density material.
    Type: Grant
    Filed: October 2, 1987
    Date of Patent: March 28, 1989
    Assignee: PPG Industries, Inc.
    Inventors: Yih-Wan Tsai, John E. Sensi
  • Patent number: 4747772
    Abstract: A multi-outlet burner for heating material. Nozzles are positioned along a longitudinally extending portion of the burner that generally parallels the material surface. Combustion gas and fuel are combined at each nozzle to produce a plurality of flames that are directed in a sweeping direction over the surface.
    Type: Grant
    Filed: February 18, 1987
    Date of Patent: May 31, 1988
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4738702
    Abstract: The circulation of exhaust gas within a heating vessel is controlled to reduce the adverse effects of the abrasive and corrosive exhaust gas on exposed interior surfaces of the vessel. The firing rates of the burners in the vessel may be varied to alter the flow patterns within the vessel. Additional jet burners with high exhaust gas velocity may be used to direct their exhaust flow in a direction opposing the exhaust flow of other selected burners. Burners may also be angled so as to reduce the flow component of the exhaust gas that may pass over the exposed interior surfaces of the vessel.
    Type: Grant
    Filed: October 6, 1986
    Date of Patent: April 19, 1988
    Assignee: PPG Industries, Inc.
    Inventors: Jeffrey S. Yigdall, Yih-Wan Tsai
  • Patent number: 4678491
    Abstract: Exhaust from a melting vessel passes through a transition section and into a rotary kiln to preheat batch material. A gas jet injects a high velocity gas stream into the transition section to alter its flow and reduce buildup of material due to entrained material in the exhaust leaving sticky deposits on interior surfaces of the transition section and kiln.
    Type: Grant
    Filed: November 18, 1985
    Date of Patent: July 7, 1987
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4675041
    Abstract: In a heating vessel wherein corrosive exhaust degrades exposed positions of the vessel, a high velocity gas jet injects gas between the corrosive exhaust and the exposed portions of the vessel. The gas minimizes contact between the exhaust and the exposed portions so as to reduce wear due to corrosive degradation.
    Type: Grant
    Filed: December 19, 1985
    Date of Patent: June 23, 1987
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4671765
    Abstract: A multi-outlet burner for heating material. Nozzles are positioned along a longitudinally extending portion of the burner that generally parallels the material surface. Combustion gas and fuel are combined at each nozzle to produce a plurality of flames that are directed in a sweeping direction over the surface.
    Type: Grant
    Filed: February 19, 1986
    Date of Patent: June 9, 1987
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4565560
    Abstract: A burner tip for passing fuel into a glass melting chamber, the burner tip having at least a portion thereof extending a distance into a fuel input passageway fluidly communicating the chamber interior to the chamber exterior, the distance being sufficient to minimize inspiration of chamber exterior or ambient air through an unsealed space formed between the outside surface of the burner tip and the walls forming the fuel input passageway, into the chamber interior, wherein at least the portion of the burner tip which extends into the fuel input passageway is made of high temperature, high oxidation-resistant material capable of withstanding the chamber interior atmosphere during both firing and off-firing cycles, while in direct contact therewith over a substantial time period.
    Type: Grant
    Filed: December 19, 1984
    Date of Patent: January 21, 1986
    Assignee: PPG Industries, Inc.
    Inventors: John F. Krumwiede, Yih-Wan Tsai
  • Patent number: 4527617
    Abstract: Regenerator packing members are constructed and arranged to form tapered passageways interconnecting regenerator flues to induce transverse flow of gas between flues for increased heat transfer. A preferred embodiment includes parallelepiped bricks arranged in an open basketweave pattern, with spaces between brick ends and side faces defining the tapered passageways.
    Type: Grant
    Filed: September 30, 1983
    Date of Patent: July 9, 1985
    Assignee: PPG Industries, Inc.
    Inventors: Robert Gagne, Yih-Wan Tsai
  • Patent number: 4506726
    Abstract: In a regenerative furnace of the type used for melting glass, localized overheating of the regenerator packing is minimized, heating of the regenerator packing is made more uniform, and regenerator efficiency is improved by employing flow control gas jets in the space alongside the regenerator packing to counteract flow imbalances in the regenerator.
    Type: Grant
    Filed: February 28, 1983
    Date of Patent: March 26, 1985
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4496316
    Abstract: A method of and apparatus for selective control of combustion gas flow in a furnace firing port in a furnace of the type having a plurality of firing ports, each port having a passageway for receiving combustion gas, e.g. preheated air, from a common plenum chamber, wherein the chamber includes a back or target wall in opposed spaced relationship to each of the passageways. A flow control pipe is inserted through a plenum wall directed toward the passageway between the plenum and port. A small quantity of pressurized gas, e.g. air, is injected generally along the flow path of combustion air in the plenum toward passageway to alter the amount of combustion air flowing into the port. In a preferred embodiment, combustion air is increased by injecting air through a target wall flow control pipe cocurrent with the flow to induce additional flow into the port and combustion air is decreased by injecting air countercurrent to the flow adjacent to the passageway to impede flow into the port.
    Type: Grant
    Filed: July 5, 1983
    Date of Patent: January 29, 1985
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4257476
    Abstract: In a regenerative furnace of the type used for melting glass, localized overheating of the regenerating regenerator packing is minimized and heating of the regenerator packing is made more uniform by the utilization of a manifold flue. The gas distribution space is in continuous contact with the regenerator packing while the manifold flue is joined to said gas distribution space at a plurality of points below the regenerative packing. Further, flow control dampers may be located in the flue between the regenerative packing and the joining point of the manifold flue and another damper may be in the manifold flue itself to regulate the passage of gas to and from the regenerative packing so that the packing is evenly heated or cooled.
    Type: Grant
    Filed: March 29, 1979
    Date of Patent: March 24, 1981
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4256173
    Abstract: In a regenerative furnace of the type used for melting glass, localized overheating of the regenerating regenerator packing is minimized and heating of the regenerator packing is made more uniform by the utilization of a second flue. The first flue passage is in continuous contact with the regenerative packing while the second passage is joined to said first passage at points at each end of the regenerative packing. Further, there are flow control dampers located in said first passageway between the regenerative packing and the joining point of the second bypass flue and another damper in the bypass flue itself to regulate the passage of hot gas to and from the regenerative packing so that the packing is evenly heated or cooled.
    Type: Grant
    Filed: March 29, 1979
    Date of Patent: March 17, 1981
    Assignee: PPG Industries, Inc.
    Inventors: Yih-Wan Tsai, Robert H. Duffus
  • Patent number: 4088180
    Abstract: In a regenerative furnace of the type used for melting glass, localized overheating of the regenerator packing is minimized, heating of the regenerator packing is made more uniform, and regenerator efficiency is improved by employing a movable baffle in the space beneath the regenerator packing and/or by a baffle in the plenum above the packing.
    Type: Grant
    Filed: February 17, 1977
    Date of Patent: May 9, 1978
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4047560
    Abstract: In a regenerative furnace of the type used for melting glass, localized overheating of the regenerator packing is minimized, heating of the regenerator packing is made more uniform, and regenerator efficiency is improved by employing a movable baffle in the space beneath the regenerator packing and/or by a baffle in the plenum above the packing.
    Type: Grant
    Filed: July 8, 1975
    Date of Patent: September 13, 1977
    Assignee: PPG Industries, Inc.
    Inventor: Yih-Wan Tsai
  • Patent number: 4045197
    Abstract: An apparatus and method are provided for recovering waste heat from the exhaust of a combustion-heated glass melting furnace and transferred by heat pipes to an enclosure in which incoming glass batch materials are preheated prior to being fed to the furnace for melting. The batch materials are efficiently preheated with the waste heat without permitting direct contact between the exhaust effluent and the batch materials so that the entrainment and discharge of batch dust with the effluent is avoided.
    Type: Grant
    Filed: September 8, 1976
    Date of Patent: August 30, 1977
    Assignee: PPG Industries, Inc.
    Inventors: Yih-Wan Tsai, John E. Sensi, Vincent I. Henry