Having Secondary Air Mixing Means Patents (Class 110/265)
  • Patent number: 6269755
    Abstract: Various burner configurations for combustion of a particulate fuel such as sawdust, and many types of varying moisture content biomass fuels such as poultry litter. The burners exhibit a high turndown ratio. the burners include a housing defining an upright combustion chamber lined with refractory material and generally circular cross section, a main combustion region within an upper extent the combustion chamber, an initial combustion zone at a lower end of the combustion chamber of reduced-size cross-section compared to the combustion chamber and a transition region increasing in cross-section from the initial combustion zone to the main combustion region. A principal fuel (e.g., sawdust) is supplied with combustion air to the initial combustion region, and an auxiliary ignition fuel supplies heat to the initial combustion region for igniting the principal fuel.
    Type: Grant
    Filed: July 29, 1999
    Date of Patent: August 7, 2001
    Assignee: Independent Stave Company, Inc.
    Inventors: John J. Boswell, Dale R. Eichmeyer
  • Patent number: 6260491
    Abstract: A nozzle for feeding combustion maintaining medium into a furnace at high temperature conditions includes a nozzle tip, at least partly protruding into the furnace, and a feeding mechanism for feeding the combustion medium from a source of the medium to the nozzle tip. The nozzle tip includes a mainly open ended outer shell, an air cooling zone, a shroud, and an air channel. The outer shell includes a first end wall portion in flow connection with the feeding mechanism and a second end wall portion protruding into the furnace. The cooling zone is formed on the interior side of at least a portion of the second end wall portion of the outer shell, by providing an air flow along the interior side. The shroud includes a shroud wall portion disposed to cover at least a portion of the first end wall portion of the outer shell.
    Type: Grant
    Filed: September 13, 1999
    Date of Patent: July 17, 2001
    Assignee: Foster Wheeler Corporation
    Inventor: John Grusha
  • Patent number: 6202578
    Abstract: A method and reactor for processing fuels with a wide particle size distribution, particularly for flame combustion. The fuel is blown tangentially with the aid of an airflow into a swirl chamber containing a burning mass, thus creating a vortex, from the center of which a flow of material is led out of the swirl chamber. The vortex created by the feed of the fuel-air mixture and the diameter of the outlet flow are arranged to create a selective delay for coarse particles, so that the size of the particles is reduced, through mechanical treatment caused by evaporation, pyrolysis, and collision, to become smaller than the desired limit value, before they escape from the swirl chamber. The temperature of the cylindrical jacket of the swirl chamber is held below the melting point of the ash.
    Type: Grant
    Filed: March 24, 1998
    Date of Patent: March 20, 2001
    Assignee: Vapo Oy
    Inventors: Seppo Ruottu, Markku Miettinen, Mauno Oksanen
  • Patent number: 6199494
    Abstract: The firing performance of a radial, scroll, or vortex cyclone furnace can be improved when firing difficult to burn materials having a relatively low heating value or a relatively high moisture content, such as sub-bituminous and lignite coals. This can be achieved by introducing additionally heated primary air into the burner of the radial and vortex cyclone furnace or separately introducing preheated or additionally heated auxiliary air into the scroll burner. Moreover, additionally heated tertiary air can be introduced into the radial and scroll burners to further improve firing performance. Moreover, additionally heated primary air can be mixed with the coal before introducing the mixture into the scroll burner to further improve firing performance.
    Type: Grant
    Filed: August 3, 1999
    Date of Patent: March 13, 2001
    Inventor: Edwin M. Griffin
  • Patent number: 6189464
    Abstract: A combustion method utilizing a pulverized coal combustion burner which is provided with a pulverized coal nozzle for jetting a fluid mixture of pulverized coal and air and an air nozzle for jetting air. In the method, a combustion flame formed by the pulverized coal combustion burner forms a first zone of a gas phase air ratio of one or less at a radially central portion of the flame and a second zone of a gas phase air ratio of more than one outside of the first zone adjacent the coal nozzle, and a third zone of a gas phase air ratio of one or less at a downstream side from said first and second zones.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: February 20, 2001
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Hirofumi Okazaki, Hironobu Kobayashi, Toshikazu Tsumura, Kenji Kiyama, Tadashi Jimbo, Kouji Kuramashi, Shigeki Morita, Shinichiro Nomura, Miki Shimogori
  • Patent number: 6167818
    Abstract: A cyclone furnace includes a cylindrical shaped furnace chamber having an inlet end for the introduction of fuel-air and an outlet end defining a re-entrant throat member. A monolithic deflector cone and orifice member comprised of a castable ceramic refractory material is secured to the re-entrant throat member.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: January 2, 2001
    Assignee: Cyclone Combustion Enhancement Group, LLC
    Inventor: Daniel Dejanovich
  • Patent number: 6152051
    Abstract: A combustion burner includes a mixture nozzle, a gas supply nozzle, and a flow guide. The mixture nozzle extends toward an interior of a furnace, and defines a mixture passage through which a mixture containing powdered solid fuel and gas for transferring the solid fuel flows. A distal end portion of the mixture nozzle is flared so that a flow passage area of the mixture passage increases progressively in a direction of flow of the mixture. The gas supply nozzle radially surrounds the mixture nozzle to define between the gas supply nozzle and the mixture nozzle a gas passage through which a combustion oxygen-containing gas flows toward the furnace. The flow guide is provided within the mixture nozzle at a position upstream of the flared portion of the mixture nozzle with respect to a flow of the mixture so as to make the mixture flow straight along an inner peripheral surface of the flared portion of the mixture nozzle.
    Type: Grant
    Filed: April 20, 1998
    Date of Patent: November 28, 2000
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Kenji Kiyama, Toshikazu Tsumura, Tadashi Jimbo, Koji Kuramashi, Shigeki Morita, Miki Mori
  • Patent number: 6145450
    Abstract: A burner assembly in which an inlet is located at one end of a tubular member thereof for receiving a fuel/air mixture, and an outlet is located at the other end of the tubular member for discharging the mixture. Secondary air is directed towards the outlet and a register vanes are provided in the path of secondary air flow for regulating the quantity of air flowing through the paths. A stabilizer vane extends from the outer surface of the burner housing and is constructed and arranged to stabilize the secondary air flow without affecting the discharge of the fuel from the burner.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: November 14, 2000
    Assignee: Foster Wheeler Corporation
    Inventor: Joel Vatsky
  • Patent number: 6146130
    Abstract: A compound spin vane (CSV) for use in an air passage of a fossil fuel-fired burner. In one embodiment, the CSV is a multi-piece construction of platelike outer and inner vane elements connected to an intermediate platelike rail element. In another embodiment, the CSV includes at least two and possibly three vane portions, rigidly interconnected in spaced lateral relationship with respect to each other. If desired, the vane portions may be simple, curved planar surfaces, and may be arranged with trailing edges arranged at angles with respect to each other. The invention may be employed as a replacement for flat spin vanes found in secondary air passages of known single and dual register burners. When used in such manner in a single register burner, the invention changes secondary air flow characteristics so as to mimic those commonly found in a dual register burner.
    Type: Grant
    Filed: October 26, 1998
    Date of Patent: November 14, 2000
    Assignee: The Babcock & Wilcox Company
    Inventors: Hamid Sarv, Jeffrey A. LaRose, Albert D. LaRue, Peter W. Waanders
  • Patent number: 6116171
    Abstract: A pulverized coal combustion burner has a circumferential distribution of pulverized coal density at an outlet portion of a pulverized coal nozzle made uniform, and a complete NO.sub.x decrease is attained. An oil gun (01) for stabilizing combustion is provided at a center portion. An annular sectional oil primary air flow path (02) surrounds the oil gun (01), and an annular sectional pulverized coal and primary air mixture flow path (14) surrounds the oil primary air flow path (02). Around the mixture flow path (14) is an annular sectional secondary air flow path (15), and an annular sectional tertiary air flow path (16) surrounds the secondary air flow path (15). A pulverized coal supply pipe is connected in the tangential direction to the mixture flow path (14). Further, an entering angle control (28) of the mixture is provided within the pulverized coal supply pipe (11). Within the mixture flow path (14), a pulverized coal density dividing cylinder (25) is provided.
    Type: Grant
    Filed: November 9, 1995
    Date of Patent: September 12, 2000
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Hideaki Oota, Toshimitsu Ichinose, Masaharu Ooguri, Hitoji Yamada
  • Patent number: 6109911
    Abstract: A method and an arrangement for reducing emissions of nitrogen oxides in a combustion apparatus provided with a tubular furnace. The method comprises burning odor gases at first sub-stoichiometrically, and subsequently supplying additional air to the furnace (3) in the transverse direction thereof in such a manner that the final air ratio is over 1. The arrangement comprises an additional air duct (7) which extends to the furnace of the boiler and from which additional air is supplied to the furnace (3) in the transverse direction of the furnace (3).
    Type: Grant
    Filed: October 7, 1998
    Date of Patent: August 29, 2000
    Assignee: Kvaerner Pulping Oy
    Inventors: Ari Tamminen, Risto Syrjalainen, Heikki Koivuniemi, Erkki Valimaki
  • Patent number: 6024030
    Abstract: A burner for combustion of a pulverized coal mixture having two kinds of rich and lean concentration has a height of a burner panel reduced and the overall burner simplified. A rich/lean separator (10, 20, 30) is provided within a pulverized coal conduit (2) so that a high concentration mixture is formed in an outer peripheral portion and a low concentration mixture is formed in a central portion within a single pulverized coal conduit. Thus, a rich mixture burner and a lean mixture burner, which have been conventionally provided separately, may be formed into a single burner. Recirculation of air is accelerated by a cutaway slit (20d, 30d) provided in a central portion of the rich/lean separator to make the air flow rate distribution uniform in a pulverized coal nozzle. Also, a duct and an air blow box for the combustion air to be supplied to the pulverized coal flame are not integrally formed continuous in the height direction, but are divided into a plurality of discontinuous units.
    Type: Grant
    Filed: June 3, 1997
    Date of Patent: February 15, 2000
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Akiyasu Okamoto, Kimishiro Tokuda, Koutaro Fujimura, Hachiro Kawashima, Shouichi Kai, Tadashi Gengo, Kouichi Sakamoto
  • Patent number: 5979342
    Abstract: A burner for the combustion of coal dust in which a stream of primary air and coal dust mixture is conducted through a dust conduit connected to a primary dust tube. A secondary air tube surrounds the primary dust tube, and a tertiary air tube surrounds the secondary air tube. The secondary and tertiary air tubes are connected to a helically-shaped input housing, and a conically flared section extends from each of the secondary and tertiary air tubes. An angular momentum is applied in the dust conduit divides the primary air and coal dust mixture into high-dust and low-dust partial streams, so that the high-dust partial stream flows through the primary dust tube, and the low-dust partial stream flows through the primary gas tube.
    Type: Grant
    Filed: August 14, 1998
    Date of Patent: November 9, 1999
    Assignee: Babcock Lentjes Kraftwerkstechnik GmbH
    Inventors: Alfons Leisse, Michael Streffing
  • Patent number: 5960723
    Abstract: A method and apparatus retrofitted to a multiple-intertube pulverized-coal burner to reduce NO.sub.x emissions of roof fired boilers. An internal two stage process controls the amount of secondary air which flows to the burner. The first stage includes a secondary air damper and air flow station to regulate the amount of air which flows into a windbox of the burner. A baffle plate assembly which includes a plurality of baffle plates further limits the amount of air which flows to the core of the burner for combustion of the fuel. The baffle plates create a pressure drop within the windbox which forces or diverts a quantity of air to the periphery of the burner. The second stage includes an outlet formed in the hot primary air duct, an air plenum which communicates therewith, and a plurality of interjectory air ports which correspond with the burners in number and position along a front wall of the boiler and which communicate with the air plenum.
    Type: Grant
    Filed: January 29, 1998
    Date of Patent: October 5, 1999
    Assignee: AEP Resources Service Company
    Inventors: Scott A. Vierstra, John J. Letcavits
  • Patent number: 5842426
    Abstract: A burner for combustion of a pulverized coal mixture having two kinds of rich and lean concentration has, a height of a burner panel reduced and the overall burner simplified. A rich/lean separator (10, 20, 30) is provided within a pulverized coal conduit (2) so that a high concentration mixture is formed in an outer peripheral portion and a low concentration mixture is formed in a central portion within a single pulverized coal conduit. Thus, a rich mixture burner and a lean mixture burner, which have been conventionally provided separately, may be formed into a single burner. Recirculation of air is accelerated by a cutaway slit (20d, 30d) provided in a central portion of the rich/lean separator to make the air flow rate distribution uniform in a pulverized coal nozzle. Also, a duct and an air blow box for the combustion air to be supplied to the pulverized coal flame are not integrally formed continuous in the height direction, but are divided into a plurality of discontinuous units.
    Type: Grant
    Filed: June 15, 1995
    Date of Patent: December 1, 1998
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Hideaki Ohta, Akiyasu Okamoto, Kimishiro Tokuda, Koutaro Fujimura, Hachiro Kawashima, Shouichi Kai, Tadashi Gengo, Kouichi Sakamoto, Mutsuo Kuragasaki
  • Patent number: 5829367
    Abstract: A burner for combustion of a pulverized coal mixture having two kinds of rich and lean concentration has a height of a burner panel reduced and the overall burner simplified. A rich/lean separator (10, 20, 30) is provided within a pulverized coal conduit (2) so that a high concentration mixture is formed in an outer peripheral portion and a low concentration mixture is formed in a central portion within a single pulverized coal conduit. Thus, a rich mixture burner and a lean mixture burner, which have been conventionally provided separately, may be formed into a single burner. Recirculation of air is accelerated by a cutaway slit (20d, 30d) provided in a central portion of the rich/lean separator to make the air flow rate distribution uniform in a pulverized coal nozzle. Also, a duct and an air blow box for the combustion air to be supplied to the pulverized coal flame are not integrally formed continuous in the height direction, but are divided into a plurality of discontinuous units.
    Type: Grant
    Filed: July 24, 1997
    Date of Patent: November 3, 1998
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Hideaki Ohta, Akiyasu Okamoto, Kimishiro Tokuda, Koutaro Fujimura, Hachiro Kawashima, Shouichi Kai, Tadashi Gengo, Kouichi Sakamoto, Mutsuo Kuragasaki
  • Patent number: 5829369
    Abstract: A burner having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO.sub.x burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO.sub.x back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing.
    Type: Grant
    Filed: November 12, 1996
    Date of Patent: November 3, 1998
    Assignee: The Babcock & Wilcox Company
    Inventors: Jennifer L. Sivy, Larry W. Rodgers, John V. Koslosy, Albert D. LaRue, Keith C. Kaufman, Hamid Sarv
  • Patent number: 5827054
    Abstract: A compound spin vane (CSV) for use in an air passage of a fossil fuel-fired burner. In one embodiment, the CSV is a multi-piece construction of platelike outer and inner vane elements connected to an intermediate platelike rail element. In another embodiment, the CSV includes at least two and possibly three vane portions, rigidly interconnected in spaced lateral relationship with respect to each other. If desired, the vane portions may be simple, curved planar surfaces, and may be arranged with trailing edges arranged at angles with respect to each other. The invention may be employed as a replacement for flat spin vanes found in secondary air passages of known single and dual register burners. When used in such manner in a single register burner, the invention changes secondary air flow characteristics so as to mimic those commonly found in a dual register burner.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: October 27, 1998
    Assignee: The Babcock & Wilcox Company
    Inventors: Hamid Sarv, Jeffrey A. LaRose, Albert D. LaRue, Peter W. Waanders
  • Patent number: 5823764
    Abstract: A low NOx burner comprising ducts for the primary (6), secondary (7) and tertiary air (14), arranged coaxially around its longitudinal axis, for supplying of the primary, secondary and tertiary air, respectively, to a combustion chamber (3), means for accumulation of the air (5), means to give vorticity to the primary, secondary and tertiary air (11, 15, 27) installed in the respective ducts, means for supply of fuel (23, 32, 43) arranged within said ducts to inject the fuel into said combustion chamber. The axial swirler for the secondary air (11) is formed by a plurality of blades each of which is made up of a stationary part (11a) and a mobile part (11b) connected to actuator means capable of moving it in an angular direction to give an air outlet angle of between 30.degree. and 60.degree.. The axial swirler for the tertiary air is conical in shape and has fixed blades. On the tertiary air duct a passage (16) is formed for supply of secondary and tertiary air.
    Type: Grant
    Filed: July 15, 1997
    Date of Patent: October 20, 1998
    Assignees: Ansaldo Energia S.p.A., Enel S.p.A.
    Inventors: Marco Alberti, Roberto Rizzi, Marcello Martano, Gennaro De Michele, Sergio Ligasacchi
  • Patent number: 5806443
    Abstract: To provide a pulverized coal burner capable of reducing the NOx concentration at the time of a low load, a pulverized coal burner includes a secondary air nozzle and a tertiary air nozzle concentrically positioned about the outer periphery of a fuel nozzle carrying a pulverized coal with a primary air, and two swirling flow generators are included at least one of these nozzles with a positional relation parallel to a flow of air. One of the swirling flow of the two swirling flow generators can be set strongly. And, under a condition of low air flow rate, air can be supplied from one swirling flow generator alone. Since the swirling strength of the combustion air can be increased, the concentration of NOx produced by the combustion of the pulverized coal can be reduced. Also, because the swirling strength at the time of low load can be increased, the NOx concentration can be reduced by keeping the pulverized coal flame stable.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: September 15, 1998
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Hironobu Kobayashi, Kiyoshi Narato, Masayuki Taniguchi, Tsuyoshi Kouno, Hirofumi Okazaki, Shigeki Morita, Toshikazu Tsumura
  • Patent number: 5799594
    Abstract: Method for combusting pulverized fuels in a tangentially fired boiler and reducing emission of nitrogen oxides comprises steps of feeding a substantially air-deficient mixture of fuel and primary air through a fuel feeding pipe (1) tangentially into a furnace of the boiler in order to form a reducing flame (II) aNd blowing of at least one stream of combustion air into the furnace. The invEntion is based in that the stream of primary air and fuel is caused to recirculate and turbulate at the open end (2) of the fuel feeding pipe (1) by passing it through a flame holder (9) extending into the fuel feeding pipe (1), and the stream of combustion air is directed away from the primary air/fuel stream in order to prevent the combustion air to mix into the reducing flame (II).
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: September 1, 1998
    Assignee: IVO International Oy
    Inventors: Pauli Dernjatin, Kati Savolainen, Juha Lepikko
  • Patent number: 5765488
    Abstract: A cyclone furnace combustion system and method in which a burner is mounted relative to a cyclone furnace for discharging a relatively fine particulate fuel in an axial direction into the furnace. Relatively coarse particulate fuel is discharged into the furnace in a tangential relationship thereto and air is provided in the furnace to support combustion of the fuels.
    Type: Grant
    Filed: February 13, 1996
    Date of Patent: June 16, 1998
    Assignee: Foster Wheeler Energy Corporation
    Inventor: Joel Vatsky
  • Patent number: 5746143
    Abstract: A combustion system in which a coal/primary air mixture is discharged from burners located in the corners of the furnace towards an imaginary circle disposed in the center of the furnace. Air is discharged from air nozzles also located in the corners of the furnace in two flow streams--one directed towards the center of the furnace in a combustion-supporting relation to the fuel, and the other along the inner surfaces of the furnace boundary walls to maintain an oxidizing atmosphere and minimize corrosion and slagging.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: May 5, 1998
    Inventor: Joel Vatsky
  • Patent number: 5738021
    Abstract: An air damper assembly for a coal-fired furnace in which a damper sleeve extends between two spaced walls adjacent the furnace in a manner to define an air inlet. A threaded support member is connected to the damper, and a threaded shaft is in threaded engagement with the support member. Rotation of the shaft causes corresponding movement of the support member, and therefore the damper, to vary the size of the opening and therefore the amount of air introduced into the furnace.
    Type: Grant
    Filed: February 6, 1996
    Date of Patent: April 14, 1998
    Assignee: Foster Wheeler Energy International, Inc.
    Inventors: Joel Vatsky, Walter Van Dyke
  • Patent number: 5738023
    Abstract: The invention relates to an apparatus for burning fossil fuel, for instance oil, gas, coal, biogas formed from organic waste, or the like, which apparatus comprises combustion means for burning this fuel in addition to converting means for converting the energy becoming available in this combustion into a desired form of energy, for instance a burner which can transfer the combustion heat to a heat exchanger for heating of heating medium, air or mains water, which apparatus further comprises a supply conduit for combustion air and a discharge conduit for flue gases.
    Type: Grant
    Filed: September 29, 1995
    Date of Patent: April 14, 1998
    Inventor: Bernhardt Diedrich Mennink
  • Patent number: 5727480
    Abstract: An over-fire air control system for a pulverized fuel furnace, in which a burner assembly is provided for discharging a fuel/primary air mixture along with secondary air to combust the fuel. The amount of primary air and secondary air discharge is controlled to achieve incomplete combustion, and an overfire air port is provided through which additional air is discharged to complete the combustion. The overfire air port receives two streams of air, one high in volume and low in velocity and the other low in volume and high in velocity. Dampers are provided for controlling the air streams to achieve optimum quantifies and velocities of the air. According to one embodiment, a source of one of the air streams is the primary air portion of the fuel/primary air mixture applied to the burner assembly. As a result, the formation of nitrous oxides are reduced and fairly precise air fuel ratios can be maintained despite variations in the quality of the fuel and the pressure and amount of primary air.
    Type: Grant
    Filed: April 17, 1996
    Date of Patent: March 17, 1998
    Assignee: Foster Wheeler International, Inc.
    Inventor: Juan Antonio Garcia-Mallol
  • Patent number: 5724901
    Abstract: An oxygen-enriched gas burner and method of operation thereof for incinerating and/or melting and/or vitrifying and/or performing thermal treatment and/or oxidizing ground/liquid waste materials and particularly, but not exclusively, contaminated waste materials. The burner comprises a body having annular chambers and defining an injection nozzle which is adjustable whereby to adjust the configuration of a flame and wherein the nozzle is provided, at the center thereof with an axial feed port through which the grounded solid/liquid waste material is injected within the flame. The waste material is fed axially within the flame under control pressure with the waste feed and flame configuration being adjusted independently from one another whereby the waste material is substantially incinerated without substantially affecting the combustion of the gas which would otherwise produce undesirable carbon monoxide and hydrocarbons.
    Type: Grant
    Filed: November 2, 1995
    Date of Patent: March 10, 1998
    Assignee: Gaz Metropolitan and Company Limited
    Inventors: Christophe Guy, Jamal Chaouki, Jean-Guy Chouinard
  • Patent number: 5724897
    Abstract: An improved pulverized coal burner that reduces the formation of nitrogen oxides. The coal burner includes fuel splitters that separate a mixture of primary air and coal into a plurality of streams while the mixture is discharged through a diffuser having a plurality of partially open areas and a plurality of blocked areas. After passing through the diffuser, the plurality of streams are discharged into a furnace to be burned. The plurality of partially open areas and blocked areas are created by removing sections of the diffuser and replacing the removed sections with fuel spiders. Creation of these discrete streams delays mixing with secondary air. Because primary air is supplied in sub-stoichiometric quantities, the coal in these split streams will be burned under fuel-rich conditions for the first 100 to 200 milliseconds of combustion, until the delayed mixing of secondary air occurs. Combustion in a fuel-rich environment retards formation of nitrogen oxides in two ways.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: March 10, 1998
    Assignees: Duquesne Light Company, Energy Systems Associates
    Inventors: Bernard P. Breen, John P. Bionda, James E. Gabrielson, Anthony Hallo
  • Patent number: 5720165
    Abstract: A system for burning biomass to produce hot gas including a wood processing system, a combustor, a cyclone ash separator, a turbine, and a control system. The wood processing system serves to process, dry and prepare the biomass for injection into the combustor. The biomass is injected into the bottom of the combustor. Combustion of the biomass takes place in the combustor. The resultant combustion gas enters the cyclone ash separator for removal of ash in the combustion gas. The cleaned combustion gas exits the cyclone ash separator via a duct. An air bypass assembly (104) permits and controls a flow of bypass air (129) from an annulus 98 of the cyclone ash separator into the duct to combine with the combustion gas. The combustion gas and bypass air (129) enter the turbine, where they expand to power the turbine.
    Type: Grant
    Filed: September 21, 1995
    Date of Patent: February 24, 1998
    Assignee: Bioten GP
    Inventors: Joseph W. Rizzie, Franck Picker
  • Patent number: 5713291
    Abstract: A multi-cylinder air delivery port for introducing air into a fossil fuel-fired boiler and auxiliary equipment. The air delivery port is generally comprised of a linearly translatable and rotatable bundle of open ended cylinders that allow air to be injected with a directional and/or swirling flow pattern without the use of louvered damper blades and spin vanes of conventional air delivery ports.
    Type: Grant
    Filed: April 3, 1996
    Date of Patent: February 3, 1998
    Assignee: The Babcock & Wilcox Company
    Inventor: Ted V. Mull, Jr.
  • Patent number: 5699746
    Abstract: Combustion gas is fed to a furnace, preferably a recovery boiler for combusting black liquor from cellulose pulp processing, through a gas nozzle disposed in association with a wall of the furnace. The nozzle has a longitudinal axis of elongation, an exterior, and a hollow interior. Cooling gas is directed into contact with the nozzle exterior, and typically also the furnace wall where the nozzle engages the furnace wall. The cooling gas typically moves in a direction substantially perpendicular to the longitudinal axis of the nozzle (e.g. at a velocity of between 10-30 m/sec), and cools the nozzle. Combustion gas passes through the nozzle hollow interior and enters the furnace facilitating combustion of black liquor within the furnace. Desirably the cooling gas is redirected and enters the nozzle interior as the combustion gas. The nozzle may be further cooled by cooling fins or studs on a portion of the nozzle exterior impacted by cooling gas.
    Type: Grant
    Filed: April 4, 1996
    Date of Patent: December 23, 1997
    Assignee: A. Ahlstrom Corporation
    Inventors: Samuli Nikkanen, Markku Tanttu
  • Patent number: 5687658
    Abstract: A method of burning coal with less than 10% volatiles in a burner supported by air. The coal is pulverized in a pulverizer and supplied to the burner mixed with a vehicle in the form of air. The object is more reliable ignition. The coal is separated from the air before it enters the burner and is combined into a new mixture with heated air. The second mixture is forwarded at a higher temperature and with a lower level of coal. The coal is separated from the second mixture and combined into a third mixture with heated air. The third mixture is forwarded at a higher temperature and with a higher level of coal.
    Type: Grant
    Filed: June 12, 1996
    Date of Patent: November 18, 1997
    Assignee: Babcock Lentjes Kraftwerstechnik GmbH
    Inventors: Michael Streffing, Alfons Leisse
  • Patent number: 5685242
    Abstract: A pulverized coal combustion burner includes a pulverized coal nozzle, and secondary and tertiary air nozzles provided in concentric relation to the pulverized coal nozzle. A flame stabilizing ring is provided at an outlet end of the pulverized coal nozzle. A separation wall is provided within the pulverized coal nozzle to divide a passage in this nozzle into two passages. A pulverized coal/air mixture flows straight through the two passages, so that recirculation flows of the pulverized coal/air mixture are formed in proximity to the outlet end of the pulverized coal nozzle. As a result, the ignitability of the pulverized coal, as well as a combustion rate, is enhanced, thereby reducing the amount of discharge of NOx.
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: November 11, 1997
    Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki Kaisha
    Inventors: Kiyoshi Narato, Hironobu Kobayashi, Masayuki Taniguchi, Tsuyoshi Kohno, Hirofumi Okazaki, Kazuyuki Ito, Shigeki Morita, Akira Baba
  • Patent number: 5680823
    Abstract: A pulverized fuel burner having lower emissions and lower unburned fuel losses by outwardly diverting and swirling pulverized fuel at the outlet of a fuel nozzle carrying the pulverized fuel. Diverting cone is positioned at the outlet of the fuel nozzle and include swirling plates connected there between for outwardly diverting some of the pulverized fuel and swirling a remainder of the pulverized fuel. Together these effects reduce the axial momentum of the fuel, shortening the flame and improving its emission and unburned fuel loss characteristics.
    Type: Grant
    Filed: March 22, 1995
    Date of Patent: October 28, 1997
    Assignee: The Babcock & Wilcox Company
    Inventor: Jeffrey A. LaRose
  • Patent number: 5680822
    Abstract: A solid fuel burner mountable on a boiler furnace. The forward portion of the burner is insertable through an opening in the casing of the furnace so as to extend into the furnace's combustion zone. The burner includes a tubular main body accommodating a feed screw for the solid fuel. The free end of the screw terminates in the forward portion of the burner. The other, closed end of the burner is mounted rotatably in a bearing. A drive rotates the feed screw inside the main body. An ignition chamber is disposed at the forward end portion. One open end of the ignition chamber meets up with the main body and the feed screw terminating within the chamber. An air supply duct with its delivery end in the chamber supplies combustion air to the fuel. An inlet in the main body gives access to the screw and thus permits the supply of fuel from a solid fuel container to the feed screw.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: October 28, 1997
    Inventor: Jorgen Hallberg
  • Patent number: 5678499
    Abstract: A system and method for preheating a mixture of fuel and air as the mixture is introduced into a furnace combustion chamber comprises passing the mixture through a nozzle extending into an upstream portion of an opening defined in a wall enclosing the combustion chamber. The nozzle is sized so that an annular space is formed between the nozzle and the opening. Hot air is introduced through the annular space and mixes with and preheats, in a downstream portion of the opening, the mixture passing through the nozzle. The preheated mixture then passes into the furnace combustion chamber for combustion therein.
    Type: Grant
    Filed: July 3, 1995
    Date of Patent: October 21, 1997
    Assignee: Foster Wheeler Energy Corporation
    Inventor: Juan Antonio Garcia-Mallol
  • Patent number: 5662464
    Abstract: A multi-directional after-air port for controlling air flow to a furnace in a staged combustion system has multiple sets of louvers or dampers oriented perpendicular to each other for improved control over combustion air-flow direction.
    Type: Grant
    Filed: September 11, 1995
    Date of Patent: September 2, 1997
    Assignee: The Babcock & Wilcox Company
    Inventors: Jeffrey A. LaRose, Mitchell W. Hopkins, Melvin J. Albrecht
  • Patent number: 5651320
    Abstract: A burner for burning powdered fuel in air. The air is divided into concentric annular currents. A tube (6) conveys primary air or gas. The tube is surrounded by another tube (12). The second tube conveys secondary air. The exit of the primary-air tube inside the secondary-air tube is surrounded by an annular baffle (26). The baffle is open at each end, has secondary air flowing through it, and extends axially beyond the primary-air tube as much as 25% of the tube's outside diameter. The thickness of the gap (25) between the primary-air tube and the baffle is at least 1.5% of that diameter.
    Type: Grant
    Filed: January 6, 1995
    Date of Patent: July 29, 1997
    Assignee: Babcock Lentjes Kraftwerkstechnik GmbH
    Inventors: Alfons Leisse, Michael Streffing
  • Patent number: 5649494
    Abstract: A burner (10) for the combustion of fuel comprises a passage (32) through which in operation a mixed flow of fuel and air passes for primary combustion at it's outlet. Two further annular passages (34, 36), concentric with and radially outward of the passage (32), are provided through which supplementary flows of air pass to support the primary combustion. The outlets of the two annular passages (34, 36) diverge to discharge the supplementary flows of air at an angle to the mixed flow of fuel and air. Members (62) are provided in the annular passage which obstruct the discharge of the supplementary flow of air. Furnace gases circulate in the region downstream of the obstruction members (62). Circulation of the furnace gases delays the mixing of the fuel and air mixture with the supplementary air flows to reduce the nitrogen oxides produced.
    Type: Grant
    Filed: February 10, 1995
    Date of Patent: July 22, 1997
    Assignee: Rolls-Royce Power Engineering plc
    Inventor: Peter F. Hufton
  • Patent number: 5593298
    Abstract: For reducing pollutant generation in a tangentially fired furnace, a method and apparatus for modification of a main air-fuel compartment. An extender dish for mounting on the discharge face of the compartment has a wide projection to extend across the discharge face half portion closer to the axis of the fireball in the furnace firing chamber and a narrow projection to extend across the discharge face half portion further from the fireball axis. Preferably a flow restricting plate is also provided to extend across a part of the discharge face portion closer to the axis of the fireball. These air restricting means cause a portion of the combustion air from the main air-fuel compartment discharge face to be directed outside the fireball therein reducing oxygen concentration and flame temperature thereby lowering pollutant generation.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: January 14, 1997
    Assignee: Combustion Components Associates, Inc.
    Inventors: John F. Hurley, Edward O. Hartel
  • Patent number: 5568777
    Abstract: An improved pulverized coal burner that reduces the formation of nitrogen oxides. The coal burner includes fuel splitters that separate a mixture of primary air and coal into a plurality of streams while the mixture is discharged through a diffuser having a plurality of partially open areas and a plurality of blocked areas. After passing through the diffuser, the plurality of streams are discharged into a furnace to be burned. The plurality of partially open areas and blocked areas are created by removing sections of the diffuser and replacing the removed sections with fuel splitters. Creation of these discrete streams delays mixing with secondary air. Because primary air is supplied in sub-stoichiometric quantities, the coal in these split streams will be burned under fuel-rich conditions for the first 100 to 200 milliseconds of combustion, until the delayed mixing of secondary air occurs. Combustion in a fuel-rich environment retards formation of nitrogen oxides in two ways.
    Type: Grant
    Filed: December 20, 1994
    Date of Patent: October 29, 1996
    Assignees: Duquesne Light Company, Energy Systems Associates
    Inventors: Bernard P. Breen, John P. Bionda, Jr., James E. Gabrielson, Anthony Hallo
  • Patent number: 5544596
    Abstract: The present invention relates to a method of supplying coal and sulphur absorbent to a combustor with combustion in a fluidized bed. The coal is crushed and sorted into a fine and a coarse fraction. The fine fraction is mixed with water, possibly with oil and/or emulsifier, into a paste which is pumped into the bed of the combustor via a number of first nozzles. The coarse coal fraction is supplied to the combustor pneumatically in dry state, directly or via at least one lock hopper systems and a number of other nozzles. The invention also relates to a power plant for application of the method.
    Type: Grant
    Filed: September 2, 1994
    Date of Patent: August 13, 1996
    Assignee: ABB Stal AB
    Inventor: Roine Brannstrom
  • Patent number: 5542361
    Abstract: The invention relates to a method for feeding a reaction gas, such as oxygen or oxygen-enriched air to a flash smelting furnace through a concentrate burner, so that the gas is fed in around a pulverous material distribution channel located in the middle of the burner. Oxygen or oxygen-enriched air is fed into the reaction shaft through tubular channels in several separate gas jets, and the discharge velocity of the gas jets is adjusted.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: August 6, 1996
    Assignee: Outokumpu Research Oy
    Inventors: Launo L. Lilja, Valto J. Makitalo
  • Patent number: 5530176
    Abstract: A method and apparatus for disposing of hazardous waste material by burning in a cement-producing kiln includes providing a predetermined quantity of hazardous waste material in a predetermined configuration, and providing an apparatus for aerating and using that apparatus to aerate the hazardous waste material to produce a supplementary fuel having a predetermined density. The method also includes providing an apparatus for injecting the hazardous waste material into the cement kiln and includes the step of injecting the hazardous waste material into the cement kiln at a predetermined injection rate thereby causing the hazardous waste material to burn while suspended in the kiln atmosphere and causing the hazardous waste material to supplement the primary fuel source and maintaining the cement-producing temperature within the kiln.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: June 25, 1996
    Assignee: Pneu-Mech Systems Mfg., Inc.
    Inventor: David Brady
  • Patent number: 5515794
    Abstract: An improved burner for partial oxidation process gas generators is provided which has annular passages formed between coaxially aligned conduits extending from upstream sources to the downstream reaction zone. An outer coolant jacket, internally baffled from optimum coolant flow and sized for minimum downstream area surrounds a recessed and fuel/oxidizer delivery conduit ending in a nozzle. The central delivery conduit is not attached to the coolant jacket and the annular space between them is connected to a high pressure supply of relatively inert gas which can periodically be vented through the annular space to prevent slag build up on the nozzle or coolant jacket.
    Type: Grant
    Filed: January 23, 1995
    Date of Patent: May 14, 1996
    Assignee: Texaco Inc.
    Inventors: Jerrold S. Kassman, Allen M. Robin, John D. Winter, James K. Wolfenbarger
  • Patent number: 5505146
    Abstract: A burner system for a furnace includes horizontal rows of cell burners some of which contain a secondary air port vertically spaced from a coal nozzle. The cell burners are in the front and rear walls of the furnace. Near the side walls of the furnace, which are connected between the front and rear walls, additional double-burner cells are provided which include a pair of vertically spaced coal nozzles or burners. Either a single lower row or a lower and upper row of cell burners include the double-burner cells at the side walls. The double cell burners are operated at 1.0 or higher throat stoichiometry. This reduces corrosion at the side walls while only slightly increasing NO.sub.x emission.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: April 9, 1996
    Assignee: The Babcock & Wilcox Company
    Inventor: Thomas A. Laursen
  • Patent number: 5441000
    Abstract: A secondary air distribution for a furnace in which an housing is provided for receiving air and a set of dividers are located in the housing for dividing the air passing through the housing into a plurality of streams. A set of dampers are disposed in the housing and are located relative to the dividers for controlling the flow of each of said streams. Additional dividers are provided for splitting each of the streams of air flow and an additional set of dampers are disposed in the housing and are positioned relative to the additional dividers for controlling the flow of each of the split stream portions to the modules.
    Type: Grant
    Filed: April 28, 1994
    Date of Patent: August 15, 1995
    Inventors: Joel Vatsky, Timothy W. Sweeney, Lawrence F. Newman
  • Patent number: 5431114
    Abstract: A combustion apparatus including a mixture feeding pipe for injecting a mixture of pulverized coal for combustion air into a furnace, with the mixture being then ignited. A first gas feeding passage is disposed outwardly of the mixture feeding pipe for feeding oxygen-containing gas into the furnace, with a second gas feeding passage being disposed between the gas feeding passage and the mixture feeding pipe, in a radial direction, for feeding the oxygen-containing gas into the furnace. A projection is disposed between the gas feeding passage and the mixture feeding pipe and extends at an exposed end surface thereof into the furnace beyond an exposed end of the mixture feeding pipe, with the projection being hollow for allowing the oxygen-containing gas to flow within the projection.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: July 11, 1995
    Assignee: Babcock-Hitachi Kabushiki Kaisha
    Inventors: Shigeki Morita, Kouji Kuramashi, Shigeto Nakashita, Keiji Ishii, Tadashi Jimbo, Kunio Hodozuka, Akira Baba, Hironobu Kobayashi
  • Patent number: 5417564
    Abstract: A new and improved method and apparatus for altering the firing pattern of an existing furnace of the type including at least one pair of vertically spaced apart burners mounted on a wall of the furnace and supplied with secondary air from a common windbox. The method involves cutting a rectangular panel from the furnace wall around a first burner wherein the burner is located asymmetrically toward a first panel end and spaced farther away from a vertically opposite second end of the panel. The cut-out panel is then reversed in orientation from end to end so that the first burner is then spaced farther apart at a greater distance from a second burner. The panel is reinstalled in the furnace wall in reverse orientation thereby providing a greater spacing or staging distance between the first and second burners producing a reduced level of NO.sub.x when the burners are fired.
    Type: Grant
    Filed: January 27, 1994
    Date of Patent: May 23, 1995
    Assignee: Riley Stoker Corporation
    Inventor: Oliver G. Briggs
  • Patent number: 5368825
    Abstract: A novel process and apparatus for continuously producing very fine, ultrapure ceramic powders from ceramic precursor reactants in a self-sustaining reaction system in the form of a stabilized flame thereof to form ceramic particles and wherein the thus formed ceramic particles are collected in the absence of oxygen.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: November 29, 1994
    Assignee: Aerochem Research Labs, Inc.
    Inventors: Hartwell F. Calcote, William Felder