US3927627A - Steam generating system and method utilizing exhaust gas recirculation - Google Patents

Steam generating system and method utilizing exhaust gas recirculation Download PDF

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Publication number
US3927627A
US3927627A US528364A US52836474A US3927627A US 3927627 A US3927627 A US 3927627A US 528364 A US528364 A US 528364A US 52836474 A US52836474 A US 52836474A US 3927627 A US3927627 A US 3927627A
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United States
Prior art keywords
furnace
duct
passing
exhaust gases
section
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Expired - Lifetime
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US528364A
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English (en)
Inventor
Frederick Milton Brunn
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Foster Wheeler Energy Corp
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Foster Wheeler Energy Corp
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Application filed by Foster Wheeler Energy Corp filed Critical Foster Wheeler Energy Corp
Priority to US528364A priority Critical patent/US3927627A/en
Priority to CA235,805A priority patent/CA1024021A/en
Priority to ES442039A priority patent/ES442039A1/es
Priority to JP14013975A priority patent/JPS5629162B2/ja
Application granted granted Critical
Publication of US3927627A publication Critical patent/US3927627A/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
    • F23L15/00—Heating of air supplied for combustion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C9/00—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber
    • F23C9/08—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for reducing temperature in combustion chamber, e.g. for protecting walls of combustion chamber
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Definitions

  • ABSTRACT A steam generating system and method in which a portion of the exhaust gases from a furnace section is passed through a duct system back into the furnace section to reduce the temperature in the furnace section. Air at ambient temperature is also passed directly into the duct system for cooling the exhaust gases before they are passed to the furnace section.
  • This invention relates to a steam generating system and, more particularly, to such a system in which exhaust gases from the furnace section of the system are injected back into the furnace section to reduce the temperature in the furnace section.
  • the present invention is designed to permit the introduction of exhaust gases back into the furnace section yet enable the system to operate at full capacity and permit fans having a conventional operating range to be utilized.
  • a quantity of air at ambient temperature is injected into the duct connecting the convection outlet to the furnace inlet upstream of the fan disposed in the duct to cool the exhaust gases before they are introduced into the fan and passed into the furnace section.
  • the system of the present invention comprises a furnace section, duct means for passing at least a portion of the exhaust gases from the furnace section back into the furnace section to reduce the temperature in the furnace section, and means for passing air at ambient temperature directly into the duct means for cooling the exhaust gases before they are passed back into the furnace section.
  • FIG. 1 is a schematic sectional view of the steam generating system incorporating features of the present invention
  • FIG. 2 is an enlarged, partial elevational view depicting a component of the system of FIG. 1.
  • the steam generating system and method of the present invention will be described in connection with a vapor generator which is broadly indicated by the reference numeral 10 in FIG. 1 of the drawings.
  • the generator 10 includes a radiant furnace section 12 having a bottom hopper l4 and an upper outlet area 16 to which is connected a horizontally and downwardly extending convection section 18 having an outlet 20, with a roof 22 extending over the two sections.
  • a radiant furnace section 12 having a bottom hopper l4 and an upper outlet area 16 to which is connected a horizontally and downwardly extending convection section 18 having an outlet 20, with a roof 22 extending over the two sections.
  • the furnace section 12 is in the form of an upright rectangular enclosure extending vertically from the floor of the generator and defined by front and rear walls 24 and 26, and a pair of side walls, one of which is shown by the reference numeral 28.
  • a vertical partition wall divides the convection section 18 into front and rear gas passes and that the convection section contains a plurality of superheater tubes, reheater tubes, and economizer tubes.
  • the partition wall and tubes are not shown or described in the present invention since they do not form a part of the present invention, and since they are described in detail in US. Pat. No. 3,556,059, assigned to the assignee of the present invention, the disclosure of which is incorporated by reference.
  • Each of the walls 24 and 26, the roof 22, and the walls of the convection section 18 includes an insulating portion 30, formed by a wall-like structure of a conventional insulating material.
  • the walls 24 and 26 also include a finned tube wall portion 32 disposed immediately within the insulating portion 30.
  • the wall portion 32 is formed by a plurality of tubes 34 having fins 34a extending along their lengths with the abutting tins being welded together so that the enclosures defined by the various walls are substantially gas tight.
  • a pair of lower headers 36 and upper headers 38 register with the wall portions 32 of the walls 24 and 26, it being understood that similar type headers are in registery with the wall portions of the side walls of the furnace section.
  • water is passed through the lower headers 36 and the tubes 34 of each of the wall portion 32 and is routed in a predetermined flow path by means of suitable downcomers, additional headers, etc., in a manner so that it is gradually turned into steam by virtue of the heat generated in the furnace section 12, after which the steam is superheated and routed to the upper headers 38 for collection in a conventional manner.
  • wall portions 32 can be incorporated in the walls forming the convection section 18 in which case they would function in a similar manner.
  • a duct 40 is connected to the convection section outlet 20 for receiving the hot exhaust gases passing from the convection section 18 and directing a portion of same into an air preheater 42.
  • the preheater 42 is provided with an outlet 42a for passing the exhaust gases entering therein to a stack, or the like.
  • a forced draft fan 44 is provided for passing ambient air into a duct 46 having a duct 48 connected to an inlet of the preheater 42.
  • the preheater 42 operates in a conventional manner to provide a heat exchange between the gases from the duct 40 and the air from the duct 48 to heat the air.
  • the heated air exits from the preheater 42 into a duct 50 which is connected to a wind box 52 located at the lower portion of the furnace section'12.
  • the wind box 52 functions to supply the preheated air to the furnace section 12 and includes front and rear plates 54 and 56 which are spaced from the corresponding portions of the front and rear walls 24 and 26, respectively, of the furnace section.
  • a plurality of burners 58 are supported by the plates 54 and 56 of the wind box 52 and discharge through a plurality of spaced openings formed in the furnace walls 24 and 26, it being understood that the burners may be arranged in several vertical rows with a plurality of burners in each row. Since the burners 58 are of a conventional design and form no portion of the present invention, they are shown only in general, with it being understood that they include an inlet for receiving fuel, which can be in liquid or gaseous form, or which can be a mixture of pulverized fuel and primary air, as well as an outlet of a reduced cross-section for discharging the fuel into the interior of the furnace section 12 where the fuel is combusted.
  • annular space is defined between the discharge end portion of each burner 58 and its corresponding opening in the wall 24 for permitting the passage of air from the wind box 52 into the furnace section 12 as will be described later. It is understood that in some installations, overfire ports or the like (not shown) may also be provided through which an additional portion of the air-gas mixture would pass directly into the furnace portion 12.
  • a duct 60 connects the duct 40 to the duct 50 for supplying a portion of the hot exhaust gases from the convection section 18 to the duct 50 under the force of a forced draft fan 62 disposed in the duct 60.
  • the preheated air from the preheater 42, and the recirculated exhaust gases from the convection section 18 are mixed in a mixing zone 64 located at the intersection of the ducts 50 and 60.
  • a duct 66 connects the duct 46 to the duct 60 for supplying ambient air directly from the fan 44 to the duct 60 upstream of the location of the fan 62.
  • the air thus mixes with the hot exhaust gases in the duct 60, to cool the hot exhaust gases before they are passed through the fan 62 and to the mixing zone 64.
  • a damper 70 is located in the duct 66 and in the duct 60 both upstream and downstream from the fan 62 to enable the flow rate of the air and gases passing through the respective ducts to be regulated.
  • ambient air at ambient temperature from the fan 44 is passed, via the ducts 46 and 48, into the air preheater 42 and therefore passes in heat exchange to the exhaust gases entering the preheater from the duct 40, to preheat the air before it exits from the preheater into the duct 50.
  • the preheated air passes through the duct 50 to the mixing zone 64 located at the intersection between the latter duct and the duct 60.
  • the duct 60 receives a portion of the hot exhaust gases from the duct 40 and passes same under the force of the fan 62 to the mixing zone 64 where the gases mix "with the preheated air in the duct 50 before the resulting mixture is passed into the wind box 52
  • the mixture of gases and air is then introduced into the 4 furnace section 12 through the annular spaces defined between the burners 58 and the corresponding openings in the walls 24 and 26.
  • Ambient air at ambient temperature from the fan 44 is also passed, via the ducts 46 and 66, directly to a portion of the duct 60 located upstream from the fan 62 whereby a preliminary mixing of the air and hot exhaust gases in the duct 60 occurs to reduce the temperature of the hot gases before they pass into and through the fan 62 and to the mixing zone 64.
  • the dampers can be adjusted to control the relative proportions of the exhaust gases and air through the ducts 60 and 66 and therefore control the mixing between the fluids in the duct 60 and at the mixing zone 64.
  • the temperature of the air-gas mixture applied to the fan 62 is relatively low to permit fans having a standard operating temperature range to be utilized.
  • a steam generating system comprising a furnace, means for passing at least a portion of the exhaust gases from the outlet section of said furnace back into the combustion section of said furnace, said means including a duct connecting said sections and a fan disposed in said duct, means for passing air at ambient temperature directly into said duct upstream of said fan for cooling said exhaust gases before they enter said fan, and means for passing preheated air into said duct downstream of said fan for mixing with said cooled exhaust gases before they are passed to said combustion section.
  • said means for passingpreheated air into said duct comprises a preheater, means for passing a portion of the exhaust gases from said furnace section to said preheater, means for passing ambient air to said preheater where it passes in heat exchange with said exhaust gases to preheat said ambient air, and means connecting said preheater to said duct.
  • the system of claim 1 further comprising means to pass water in a heat exchange relation to said furnace to convert the water to steam.
  • a steam generating system comprising a furnace, a preheater, first duct means for passing a portion of the exhaust gases from the outlet section of said furnace to said preheater, means for introducing ambient air into said preheater where it passes in a heat exchange relation to said exhaust gases in said preheater to heat said ambient air, second duct means for passing said heated ambient air to the combustion section of said furnace, third duet means connecting said first duct means to said second duct means, a fan disposed in said third duct means for passing a portion of the exhaust gases from said first duct means to said second duct means for mixing with said heated ambient air before passing into said combustion section of said furnace, and means for passing air at ambient temperature directly into said third duct means upstream of said fan means for cooling said exhaust gases before they pass into said fan.
  • the system of claim 5 further comprising a plurality of burners cooperating with openings formed in said combustion section of said furnace for combusting fuel in said combustion section, and a windbox extending over said burners, said second duct means passing said heated ambient air to said windbox.
  • a method for reducing the temperature in the combustion section of a furnace comprising the steps of passing at least a portion of the exhaust gases from the outlet section of said furnace through a duct and back into the combustion section of said furnace, passing air at ambient temperature directly into said duct for cooling said exhaust gases, and mixing preheated air with said cooled exhaust gases before they are passed to said combustion section.
  • the method of claim 8 further comprising the steps of passing a portion of the exhaust gases from said furnace section to a preheater, passing ambient air to said preheater where it passes in heat exchange with said exhaust gases to form said preheated air.
  • a method for reducing the temperature in the combustion section of a furnace comprising the steps of passing a portion of the exhaust gases from the outlet section of said furnace in a heat exchange relation -to ambient air to heat said ambient air, passing said heated ambient air to said combustion section of said furnace, mixing a portion of the exhaust gases from said outlet section with said heated ambient air before the latter is passed into said combustion section, and cooling said latter portion of exhaust gases before they are mixed with said ambient air.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Combustion Of Fluid Fuel (AREA)
  • Air Supply (AREA)
US528364A 1974-11-29 1974-11-29 Steam generating system and method utilizing exhaust gas recirculation Expired - Lifetime US3927627A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US528364A US3927627A (en) 1974-11-29 1974-11-29 Steam generating system and method utilizing exhaust gas recirculation
CA235,805A CA1024021A (en) 1974-11-29 1975-09-18 Steam generating system and method utilizing exhaust gas recirculation
ES442039A ES442039A1 (es) 1974-11-29 1975-10-23 Un intercambiador termico.
JP14013975A JPS5629162B2 (es) 1974-11-29 1975-11-21

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US528364A US3927627A (en) 1974-11-29 1974-11-29 Steam generating system and method utilizing exhaust gas recirculation

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JP (1) JPS5629162B2 (es)
CA (1) CA1024021A (es)
ES (1) ES442039A1 (es)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4344371A (en) * 1981-03-31 1982-08-17 Foster Wheeler Energy Corporation Vapor generating system having integrally formed gasifiers extending to either side of the hopper portion of the generator
US4457289A (en) * 1982-04-20 1984-07-03 York-Shipley, Inc. Fast fluidized bed reactor and method of operating the reactor
US4509436A (en) * 1982-09-30 1985-04-09 Osterreichische Draukraftwerke Aktiengesellschaft Method of and apparatus for the desulfurization of flue gas of a coal-fired combustion process
US4573418A (en) * 1982-12-01 1986-03-04 Steirische Wasserkraft- Und Elektrizitaets-Ag Method of and apparatus for reheating desulfurized waste gas
US4699071A (en) * 1985-01-16 1987-10-13 Henkel Kommanditgesellschaft Auf Aktien Nitrogen oxide reduction in furnaces
GR1001317B (el) * 1991-08-23 1993-08-31 Evt Energie & Verfahrenstech Μεθοδος και εγκατασταση δια τη διεξαγωγη της μεθοδου δια τη λειτουργια μιας διαταξεως παραγωγης ατμου.
US6039560A (en) * 1996-01-31 2000-03-21 Sanyo Electric Co., Ltd. Low NOx burner and method of controlling recirculation of exhaust gas
US20050257721A1 (en) * 2002-12-26 2005-11-24 Hitachi, Ltd. Solid fuel boiler and method of operating combustion apparatus
US20120129109A1 (en) * 2008-10-30 2012-05-24 Karlsruher Institut Fuer Technologie Method and device for reducing hazardous emissions in internal combustion systems
US20120145052A1 (en) * 2010-11-16 2012-06-14 Alstom Technology Ltd. Apparatus and method of controlling the thermal performance of an oxygen-fired boiler
US20150096507A1 (en) * 2013-10-03 2015-04-09 Babcock & Wilcox Power Generation Group, Inc. Advanced ultra supercritical steam generator
CN106224938A (zh) * 2016-08-31 2016-12-14 苏州迪森生物能源有限公司 一种具有三档混合风喷口的生物质锅炉系统
US20220404041A1 (en) * 2018-01-19 2022-12-22 Dri-Steem Corporation Condensing, Ultra-Low NOx Gas-Fired Humidfier

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5341745U (es) * 1976-09-14 1978-04-11
JPS5538473A (en) * 1978-09-12 1980-03-17 Takuma Kk Boiler installation capable of low nox emission and saving energy
JPH0624641Y2 (ja) * 1987-12-21 1994-06-29 大阪瓦斯株式会社 ボイラ
US9394419B2 (en) 2013-11-19 2016-07-19 Istanbul Teknik Universitesi Column filling material and a production method thereof

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2229643A (en) * 1937-01-02 1941-01-28 Superheater Co Ltd Method and apparatus for controlling temperature of superheated steam
US2603195A (en) * 1949-07-12 1952-07-15 Shell Dev Tubular heater and method of controlling radiation effects therein
US2730971A (en) * 1949-09-15 1956-01-17 Birkner Max Furnace and boiler plant
US2837066A (en) * 1954-02-25 1958-06-03 Combustion Eng Vapor generator with novel gas recirculating system
US2875736A (en) * 1955-10-26 1959-03-03 Babcock & Wilcox Co Gas recirculation method and automatic apparatus for superheat control
US2980082A (en) * 1955-02-16 1961-04-18 Combustion Eng Method of operating a steam generator
US3048131A (en) * 1959-06-18 1962-08-07 Babcock & Wilcox Co Method for burning fuel
US3781162A (en) * 1972-03-24 1973-12-25 Babcock & Wilcox Co Reducing nox formation by combustion

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS522730B2 (es) * 1972-03-06 1977-01-24
JPS4957420A (es) * 1972-10-05 1974-06-04

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2229643A (en) * 1937-01-02 1941-01-28 Superheater Co Ltd Method and apparatus for controlling temperature of superheated steam
US2603195A (en) * 1949-07-12 1952-07-15 Shell Dev Tubular heater and method of controlling radiation effects therein
US2730971A (en) * 1949-09-15 1956-01-17 Birkner Max Furnace and boiler plant
US2837066A (en) * 1954-02-25 1958-06-03 Combustion Eng Vapor generator with novel gas recirculating system
US2980082A (en) * 1955-02-16 1961-04-18 Combustion Eng Method of operating a steam generator
US2875736A (en) * 1955-10-26 1959-03-03 Babcock & Wilcox Co Gas recirculation method and automatic apparatus for superheat control
US3048131A (en) * 1959-06-18 1962-08-07 Babcock & Wilcox Co Method for burning fuel
US3781162A (en) * 1972-03-24 1973-12-25 Babcock & Wilcox Co Reducing nox formation by combustion

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4344371A (en) * 1981-03-31 1982-08-17 Foster Wheeler Energy Corporation Vapor generating system having integrally formed gasifiers extending to either side of the hopper portion of the generator
US4457289A (en) * 1982-04-20 1984-07-03 York-Shipley, Inc. Fast fluidized bed reactor and method of operating the reactor
US4509436A (en) * 1982-09-30 1985-04-09 Osterreichische Draukraftwerke Aktiengesellschaft Method of and apparatus for the desulfurization of flue gas of a coal-fired combustion process
US4573418A (en) * 1982-12-01 1986-03-04 Steirische Wasserkraft- Und Elektrizitaets-Ag Method of and apparatus for reheating desulfurized waste gas
US4699071A (en) * 1985-01-16 1987-10-13 Henkel Kommanditgesellschaft Auf Aktien Nitrogen oxide reduction in furnaces
GR1001317B (el) * 1991-08-23 1993-08-31 Evt Energie & Verfahrenstech Μεθοδος και εγκατασταση δια τη διεξαγωγη της μεθοδου δια τη λειτουργια μιας διαταξεως παραγωγης ατμου.
US6039560A (en) * 1996-01-31 2000-03-21 Sanyo Electric Co., Ltd. Low NOx burner and method of controlling recirculation of exhaust gas
US7392752B2 (en) * 2002-12-26 2008-07-01 Hitachi, Ltd. Solid fuel boiler and method of operating combustion apparatus
US20050257721A1 (en) * 2002-12-26 2005-11-24 Hitachi, Ltd. Solid fuel boiler and method of operating combustion apparatus
US20120129109A1 (en) * 2008-10-30 2012-05-24 Karlsruher Institut Fuer Technologie Method and device for reducing hazardous emissions in internal combustion systems
US9134022B2 (en) * 2008-10-30 2015-09-15 Karlsruher Institut Fuer Technologie Method and device for reducing hazardous emissions in internal combustion systems
US20120145052A1 (en) * 2010-11-16 2012-06-14 Alstom Technology Ltd. Apparatus and method of controlling the thermal performance of an oxygen-fired boiler
US9752773B2 (en) * 2010-11-16 2017-09-05 General Electric Technology Gmbh Apparatus and method of controlling the thermal performance of an oxygen-fired boiler
US20150096507A1 (en) * 2013-10-03 2015-04-09 Babcock & Wilcox Power Generation Group, Inc. Advanced ultra supercritical steam generator
US9874346B2 (en) * 2013-10-03 2018-01-23 The Babcock & Wilcox Company Advanced ultra supercritical steam generator
CN106224938A (zh) * 2016-08-31 2016-12-14 苏州迪森生物能源有限公司 一种具有三档混合风喷口的生物质锅炉系统
US20220404041A1 (en) * 2018-01-19 2022-12-22 Dri-Steem Corporation Condensing, Ultra-Low NOx Gas-Fired Humidfier
US11940178B2 (en) * 2018-01-19 2024-03-26 Dri-Steem Corporation Condensing, ultra-low NOx gas-fired humidifier

Also Published As

Publication number Publication date
JPS5175232A (es) 1976-06-29
ES442039A1 (es) 1977-03-16
JPS5629162B2 (es) 1981-07-07
CA1024021A (en) 1978-01-10

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