Patents by Inventor Mahendra L. Joshi

Mahendra L. Joshi 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).

  • Publication number: 20030157450
    Abstract: A burner apparatus comprises a conduit adapted to convey preheated oxidant and having outlet and inlet ends, and a conduit adapted to convey preheated fuel and having outlet and inlet ends. The conduit adapted to convey preheated fuel is substantially parallel to the conduit adapted to convey preheated oxidant. The conduit adapted to convey preheated oxidant is positioned substantially vertically above the conduit adapted to convey preheated fuel. The conduit adapted to convey preheated oxidant and the conduit adapted to convey preheated fuel each are positioned within its own respective elongate cavity in a refractory burner block. Each of the conduits are positioned in their respective cavity such that a substantially annular region is present between an outer surface of each conduit and its respective cavity. Each conduit inlet end extends through a respective plenum for receiving an ambient temperature fluid, the plenums adapted to pass the ambient temperature fluid into the respective annular regions.
    Type: Application
    Filed: January 3, 2003
    Publication date: August 21, 2003
    Inventors: Mahendra L. Joshi, Arnaud Fossen, Harley A. Borders, Remi P. Tsiava, Olivier Charon
  • Publication number: 20030054301
    Abstract: An oxy-fuel burner generates a long, luminous, stable and adjustable flame temperature profile flame by incorporating separate, fuel and oxygen jets oriented in a unique geometry. In one preferred embodiment, the fuel is injected horizontally at medium injection velocity (50-200 m/s) while primary oxygen is injected underneath the fuel jet at supersonic velocity (300-500 m/s). The supersonic velocity oxygen jet (20 to 50% required for stoichiometric combustion) entrains fuel and furnaces gases in it's core for the primary flame development over the furnace load. The subsequent mixing of the fuel, primary oxygen and entrained furnace gases establish a low NOx, stable, long and luminous primary flame. The secondary oxidant, preferably air or low purity oxygen (50 to 80% of stoichiometric needs), is injected above the flame using one or more oxygen jets to create an oxy-fuel flame with adjustable flame characteristics.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 20, 2003
    Inventors: Harley A. Borders, Mahendra L. Joshi, Eric Streicher, Thierry Legiret
  • Patent number: 6454562
    Abstract: A process controls oxy-boost firing and air-fuel burner firing in furnaces, including large glass furnaces such as float furnaces. The large side-fired regenerative float furnaces use oxy-boost firing for a variety of reasons, including production increase, improved glass quality, lowering of superstructure temperatures, and reduction of emissions. An adaptive controller receives input data from process parameter sensors throughout the furnace, and adjusts its control logic for controlling both the oxy-boost burners and the air-fuel port burners.
    Type: Grant
    Filed: April 20, 2000
    Date of Patent: September 24, 2002
    Assignees: L'Air Liquide-Societe' Anonyme a' Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude, American Air Liquide, Inc.
    Inventors: Mahendra L. Joshi, Ovidiu Marin
  • Publication number: 20020121108
    Abstract: A retrofit technology for air-fuel fired, vertical glass furnace for oxygen firing or boosting to provide additional heat to the process to increase furnace production capacity. The additional firing using oxygen is strategically controlled to enable enhanced radiation from oxygen flame for the spheroidizing process without negative effects on the overall process. With proper implementation, an increased production from 50% to 200%, depending on the size of the spheres, can be achieved while maintaining acceptable product quality. Processes in accordance with the present invention can be performed using one of a number of methods of oxygen boosting.
    Type: Application
    Filed: October 19, 2001
    Publication date: September 5, 2002
    Inventors: Eric Streicher, John Foss, Mahendra L. Joshi, Harley A. Borders
  • Patent number: 6431467
    Abstract: A low firing rate oxy-fuel burner which may be comprised of commercially available standard components and which includes an oxidant conduit and a fuel conduit within the oxidant conduit. The fuel conduit has a fuel nozzle at the forward end thereof with a fuel swirler in the form of a twist drill positioned therein which is maintained in a an aerodynamically centered position by the flowing fuel stream. The oxidant conduit has an oxidant nozzle at the forward end thereof with an oxidant swirler in the form of helical spring position therein and surrounding the fuel nozzle.
    Type: Grant
    Filed: January 7, 2000
    Date of Patent: August 13, 2002
    Assignee: American Air Liquide, Inc.
    Inventors: Mahendra L. Joshi, Donald J. Fournier, Jr.
  • Patent number: 6398547
    Abstract: An oxy-combustion firing configuration, process, and apparatus can reduce the consumption of oxygen and fuel in an oxy-fuel combustion processes. Processes in accordance with the present invention include operation of an automated logic control device which controls an oscillating valve and controller. The valve and controller are used to oscillate the fuel and/or oxygen supplied to individual burners in a furnace. The oscillating parameters, such as frequency, amplitude, duty cycle, and phase difference between individual burners and their stoichiometry ratio are set to initiate preferable oxy-combustion in that furnace. Selective burner placement in the furnace enables the formation of deflagration zones which can provide very intense heating and complete combustion.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: June 4, 2002
    Assignees: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude, American Air Liquide inc.
    Inventors: Mahendra L. Joshi, Harley Borders, Olivier Charon
  • Publication number: 20010044089
    Abstract: A kiln is provided with oxidant injection locations upstream of air blowers which blow air into the kiln. The addition of oxygen into the kiln increases the cooling capacity of a clinker cooler, and enhances combustion in the kiln.
    Type: Application
    Filed: July 9, 2001
    Publication date: November 22, 2001
    Inventors: Ovidiu Marin, Mahendra L. Joshi, Olivier Charon, Jacques Dugue
  • Patent number: 6309210
    Abstract: A kiln is provided with oxidant injection locations upstream of air blowers which blow air into the kiln. The addition of oxygen into the kiln increases the cooling capacity of a clinker cooler, and enhances combustion in the kiln.
    Type: Grant
    Filed: March 16, 1999
    Date of Patent: October 30, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'etude et, l'Exploitation des Procedes Georges Claude
    Inventors: Ovidiu Marin, Mahendra L. Joshi, Olivier Charon, Jacques Dugue
  • Publication number: 20010018962
    Abstract: A heat exchanger useful for preheating oxidizing gases in a combustion process includes a shell having an inlet and an outlet for the ingress and egress of a first heat exchange fluid, such as a flue gas or preheated air. A first tube manifold couples an inlet end-cap to the first end of the shell. The inlet end-cap has an inlet for receiving a second heat exchange fluid, such as an oxidizing gas. In one embodiment, a second manifold couples an outlet end-cap to the second end of the shell. The second manifold includes an outlet tube therein extending from the second manifold through an outlet opening in the outlet end-cap. A tube bundle is disposed within the shell for transporting the oxidizing gas through the heat exchanger and is coupled to the first and second tube manifolds. The outlet tube collects oxidizing gas flowing through the tube bundle for discharge to a combustion system.
    Type: Application
    Filed: January 23, 2001
    Publication date: September 6, 2001
    Applicant: American Air Liquide Inc.
    Inventors: Mahendra L. Joshi, Arnaud Fossen, Harley A. Borders, Remi Pierre Tsiava, Olivier Charon
  • Patent number: 6276928
    Abstract: An oxygen enrichment system is provided which uses the existing air/fuel burners of a regenerative furnace to distribute additional oxygen to the burners for increased efficiency, and reduced nitrous oxide emissions. The centrally positioned cooling air lances in the burners of a regenerative furnace are modified to deliver oxygen when the burners are firing for oxygen enrichment. During the burmer firing cycle, oxygen is delivered from an oxygen supply through the oxygen lance to provide a central oxygen jet. The fuel is delivered concentrically around the oxygen jet. During the non-firing cycle of the burner, cooling air or other cooling fluid is delivered from the cooling air supply through the oxygen jet for cooling the offside of the furnace.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: August 21, 2001
    Assignee: American Air Liquide, Inc.
    Inventors: Mahendra L. Joshi, Harley A. Borders, Olivier Charon
  • Patent number: 6276924
    Abstract: A self-cooled oxidant-fuel burner consisting novel fuel and oxidant nozzles and three compartment refractory burner block design is proposed. The new oxidant-fuel burner can fire in high-temperature (2200° F. to 3000° F.) and high-particulate (or high process volatiles/condensates) furnaces without over-heating or causing chemical corrosion damage to it's metallic burner nozzle and refractory burner block interior. Using various embodiments of nozzle and block shape, the burner can offer a traditional cylindrical flame or flat flame depending on the heating load requirements. The new features of this burner include unique fuel nozzle design for the streamline mixing of fuel and oxidant streams, a controlled swirl input to the oxidant flow for desired flame characteristics, a controlled expansion of flame envelope in the radial and axial dimensions, and efficient sweeping of burner block interior surface using oxidant to provide convective cooling and prevent any build up of process particulates.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: August 21, 2001
    Assignees: American Air Liquide, Inc., L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Mahendra L. Joshi, Harley A. Borders, Ovidiu Marin, Olivier Charon
  • Patent number: 6273180
    Abstract: A heat exchanger useful for preheating oxidizing gases in a combustion process includes a shell having an inlet and an outlet for the ingress and egress of a first heat exchange fluid, such as a flue gas or preheated air. A first tube manifold couples an inlet end-cap to the first end of the shell. The inlet end-cap has an inlet for receiving a second heat exchange fluid, such as an oxidizing gas. In one embodiment, a second manifold couples an outlet end-cap to the second end of the shell. The second manifold includes an outlet tube therein extending from the second manifold through an outlet opening in the outlet end-cap. A tube bundle is disposed within the shell for transporting the oxidizing gas through the heat exchanger and is coupled to the first and second tube manifolds. The outlet tube collects oxidizing gas flowing through the tube bundle for discharge to a combustion system.
    Type: Grant
    Filed: December 23, 1998
    Date of Patent: August 14, 2001
    Assignees: L'Air Liquide, Societe Anonyme pour l'Etude et l'Eploitation des Procedes Georges Claude, American Air Liquide
    Inventors: Mahendra L. Joshi, Arnaud Fossen, Harley A. Borders, Remi Pierre Tsiava, Olivier Charon
  • Patent number: 6264466
    Abstract: An oxygen enrichment system is provided which uses the existing air/fuel burners of a regenerative furnace to distribute additional oxygen to the burners for increased efficiency, and reduced nitrous oxide emissions. The centrally positioned cooling air lances in the burners of a regenerative furnace are modified to deliver oxygen when the burners are firing for oxygen enrichment. During the burner firing cycle, oxygen is delivered from an oxygen supply through the oxygen lance to provide a central oxygen jet. The fuel is delivered concentrically around the oxygen jet. During the non-firing cycle of the burner, cooling air or other cooling fluid is delivered from the cooling air supply through the oxygen jet for cooling the offside of the furnace.
    Type: Grant
    Filed: March 31, 2000
    Date of Patent: July 24, 2001
    Assignee: American Air Liquide, Inc.
    Inventors: Mahendra L. Joshi, Harley A. Borders, Olivier Charon
  • Patent number: 6241514
    Abstract: A kiln adapted to recycle kiln dust includes a recycle dust pipe in fluid communication with an oxidant stream to increase the concentration of oxygen in the fluidized recycle dust before the recycle dust stream is directed into the kiln flame. Increasing the oxygen concentration in the recycle dust stream improves the efficiency of the recycling process. A supplemental fuel stream may be introduced into the recycle dust stream to provide an additional flame to preheat the recycle dust stream before the recycle dust stream is directed into the kiln flame.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: June 5, 2001
    Assignees: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude, American Air Liquide, Inc.
    Inventors: Mahendra L. Joshi, Ovidiu Marin, Olivier Charon, Jacques Dugue
  • Patent number: 6210151
    Abstract: A self-cooled oxidant-fuel burner consisting novel fuel and oxidant nozzles and three compartment refractory burner block design is proposed. The new oxidant-fuel burner can fire in high-temperature (2200° F. to 3000° F.) and high-particulate (or high process volatiles/condensates) furnaces without over-heating or causing chemical corrosion damage to it's metallic burner nozzle and refractory burner block interior. Using various embodiments of nozzle and block shape, the burner can offer a traditional cylindrical flame or flat flame depending on the heating load requirements. The new features of this burner include unique fuel nozzle design for the streamline mixing of fuel and oxidant streams, a controlled swirl input to the oxidant flow for desired flame characteristics, a controlled expansion of flame envelope in the radial and axial dimensions, and efficient sweeping of burner block interior surface using oxidant to provide convective cooling and prevent any build up of process particulates.
    Type: Grant
    Filed: May 16, 2000
    Date of Patent: April 3, 2001
    Assignees: American Air Liquide, L'Arr Liquide Societe Anonyme pour l'Etude et, l'Exploitation des Procedes Georges Claude
    Inventors: Mahendra L. Joshi, Harley A. Borders, Ovidiu Marin, Olivier Charon
  • Patent number: 6171100
    Abstract: Burner firing method and device are presented where an oxidizing oxygen-fuel burner is fired at an angle to the reducing air-fuel burner flame to reduce overall NOx emissions from high temperature furnaces. The oxidizing oxy-fuel burner stoichiometric equivalence ratio (oxygen/fuel) is maintained in the range of about 1.5 to about 12.5. The reducing air-fuel burner is fired at an equivalence ratio of 0.6 to 1.00 to reduce the availability of oxygen in the flame and reducing NOx emissions. The oxidizing flame from the oxy-fuel burner is oriented such that the oxidizing flame gas stream intersects the reducing air-fuel flame gas stream at or near the tail section of the air-fuel flame. The inventive methods improve furnace temperature control and thermal efficiency by eliminating some nitrogen and provide an effective burnout of CO and other hydrocarbons using the higher mixing ability of the oxidizing flame combustion products.
    Type: Grant
    Filed: September 20, 1999
    Date of Patent: January 9, 2001
    Assignees: American Air Liquide, Inc., L'Air Liquide Societe Anonyme pour l'Elude et l'Exploitation des Procedes George Claude
    Inventors: Mahendra L. Joshi, Benjamin J. Jurcik, Jr., Jean-Francois Simon
  • Patent number: 6155818
    Abstract: An oxy-burner having a back-up firing system includes an oxidant conduit coupled to an oxidant injector nozzle. A primary oxygen line is coupled to the oxidant conduit and transports oxygen into the oxidant conduit. An auxiliary air ejector is coupled to the oxidant conduit and is configured to receive a motive fluid and to entrain ambient air and force the entrained air into the oxidant conduit. In operation, upon detecting a disruption in the primary oxygen supply, a motive fluid is supplied to the auxiliary air ejector. The motive fluid injected by the auxiliary air ejector entrains ambient air sufficient to either continue operation of the oxy-burner, or provide cooling air to the oxy-burner in the event that the burner is shut down. Upon restoring the primary oxygen supply, the back-up oxy-burner system can be deactivated and the oxy-burner return to standard operation.
    Type: Grant
    Filed: December 16, 1999
    Date of Patent: December 5, 2000
    Assignees: L'Air Liquide, Societe Anonyme pour l'Etude et, l'Exploitation des Procedes, Georges Claude, Air Liquide America Corporation
    Inventors: Mahendra L. Joshi, Olivier Charon, Harley A. Borders, Roman E. Grosman
  • Patent number: 6126438
    Abstract: A burner apparatus comprises a conduit adapted to convey preheated oxidant and having outlet and inlet ends, and a conduit adapted to convey preheated fuel and having outlet and inlet ends. The conduit adapted to convey preheated fuel is substantially parallel to the conduit adapted to convey preheated oxidant. The conduit adapted to convey preheated oxidant is positioned substantially vertically above the conduit adapted to convey preheated fuel. The conduit adapted to convey preheated oxidant and the conduit adapted to convey preheated fuel each are positioned within its own respective elongate cavity in a refractory burner block. Each of the conduits are positioned in their respective cavity such that a substantially annular region is present between an outer surface of each conduit and its respective cavity. Each conduit inlet end extends through a respective plenum for receiving an ambient temperature fluid, the plenums adapted to pass the ambient temperature fluid into the respective annular regions.
    Type: Grant
    Filed: June 23, 1999
    Date of Patent: October 3, 2000
    Assignees: American Air Liquide, L'Air Liquide Societe Anonyme pour l'Etude et, l'Exploitation des Procedes Georges Claude
    Inventors: Mahendra L. Joshi, Arnaud Fossen, Harley A. Borders, Remi P. Tsiava, Olivier Charon
  • Patent number: 6123542
    Abstract: A self-cooled oxidant-fuel burner consisting novel fuel and oxidant nozzles and three compartment refractory burner block design is proposed. The new oxidant-fuel burner can fire in high-temperature (2200.degree. F. to 3000.degree. F.) and high-particulate (or high process volatiles/condensates) furnaces without over-heating or causing chemical corrosion damage to it's metallic burner nozzle and refractory burner block interior. Using various embodiments of nozzle and block shape, the burner can offer a traditional cylindrical flame or flat flame depending on the heating load requirements. The new features of this burner include unique fuel nozzle design for the streamline mixing of fuel and oxidant streams, a controlled swirl input to the oxidant flow for desired flame characteristics, a controlled expansion of flame envelope in the radial and axial dimensions, and efficient sweeping of burner block interior surface using oxidant to provide convective cooling and prevent any build up of process particulates.
    Type: Grant
    Filed: November 3, 1998
    Date of Patent: September 26, 2000
    Assignees: American Air Liquide, L'Air Liquide, Societe Anonyme pour l'Etude et, l'Exploitation des Procedes Georges Claude
    Inventors: Mahendra L. Joshi, Harley A. Borders, Ovidiu Marin, Olivier Charon
  • Patent number: 6116896
    Abstract: A system and method for increasing the amount of oxygen in a kiln chamber is disclosed. The radial surface of a rotatable kiln is provided with at least one oxidant injection port extending through the radial surface into the kiln chamber. A cam is connected to the radial surface adjacent the oxidant injection port. A valve assembly including a valve chamber in fluid communication with an oxidant supply is mounted adjacent the kiln substantially in fixed spatial relation with the rotatable kiln body. The valve assembly includes a follower member adapted to contact a surface to the cam to actuate the valve assembly. Rotation of the kiln body brings the cam into contact with the follower member, thereby actuating the oxidant injection assembly, and injecting oxidant through the injection port into the kiln chamber.
    Type: Grant
    Filed: September 15, 1999
    Date of Patent: September 12, 2000
    Assignees: Air Liquide America Inc., L'Air Liquide, Societe Anonyme pour l'Etude Et, l'Exploitation des Procedes Georges Claude
    Inventors: Mahendra L. Joshi, Ovidiu Marin, Olivier Charon, Jacques Dugue