CN1977128B - Method for burning refining residues - Google Patents

Method for burning refining residues Download PDF

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Publication number
CN1977128B
CN1977128B CN2005800215017A CN200580021501A CN1977128B CN 1977128 B CN1977128 B CN 1977128B CN 2005800215017 A CN2005800215017 A CN 2005800215017A CN 200580021501 A CN200580021501 A CN 200580021501A CN 1977128 B CN1977128 B CN 1977128B
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CN
China
Prior art keywords
burner hearth
injector
gas
residue
described device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CN2005800215017A
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Chinese (zh)
Other versions
CN1977128A (en
Inventor
让-泽维尔·莫林
克里斯琴·埃诺尔特
让-克劳德·福彻
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General Electric Technology GmbH
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Alstom Technology AG
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Filing date
Publication date
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Publication of CN1977128A publication Critical patent/CN1977128A/en
Application granted granted Critical
Publication of CN1977128B publication Critical patent/CN1977128B/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
    • F23L7/00—Supplying non-combustible liquids or gases, other than air, to the fire, e.g. oxygen, steam
    • F23L7/007—Supplying oxygen or oxygen-enriched air
    • 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 
    • F23C1/00—Combustion apparatus specially adapted for combustion of two or more kinds of fuel simultaneously or alternately, at least one kind of fuel being either a fluid fuel or a solid fuel suspended in a carrier gas or air
    • 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 
    • F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
    • F23C5/08—Disposition of burners
    • F23C5/32—Disposition of burners to obtain rotating flames, i.e. flames moving helically or spirally
    • 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
    • F23C9/003—Combustion apparatus characterised by arrangements for returning combustion products or flue gases to the combustion chamber for pulverulent fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D1/00—Burners for combustion of pulverulent fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
    • F23G7/00—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals
    • F23G7/008—Incinerators or other apparatus for consuming industrial waste, e.g. chemicals for liquid waste
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2214/00—Cooling
    • 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

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Environmental & Geological Engineering (AREA)
  • Combustion Of Fluid Fuel (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Abstract

The present invention relates to a method for burning crude oil refining residues in a boiler, including a furnace and injectors, characterized in that cooled gas containing oxygen is injected into the furnace in the hottest portion thereof to cause cracking of the tar or polycyclic aromatic hydrocarbons and the conversion thereof into basic materials that burn readily and thus pollute less.

Description

The method that is used for burning refining residues
Technical field
The present invention relates to a kind ofly be used to burn from the residue of refining petroleum and make the method and apparatus of the minimum emissions of nitrogen oxide and dust.
Background technology
These residues comprise tar, pitch and pitch, and it has lower commercial value, especially comprise at room temperature for solid-state and in the time of 100 ℃ viscosity surpass the product of 500 centistokes (centistokes).They are often burnt for the purpose of oneself by refinery.In Europe, the production that for example is used for the light diesel fuel of motor vehicle causes producing these residues.
Their burnings in conventional boiler are unfavorable for environment, in Europe, particularly in France, make this scheme become impossible at the new standard of the discharging of sulfur oxide.These restrictions also will be applied to dust, polycyclic aromatic hydrocarbons (PAH) and volatile organic compound.
In order to replace these residues of burning, can adopt processing, and the processing of these other forms is more complex and expensive to other less form of environmental hazard.Therefore, can adopt evaporating method, it is attached in the combined cycle or takes these residues are changed into the form of dark conversion process of the final residue (for example, petroleum coke) of economic worth.
The present increase output of what is called " the bucket end " residue (tar) that burns in conventional boiler of refinery particularly in Europe, also will cause these residues are handled changing.
Summary of the invention
The objective of the invention is to propose a kind of method and injection apparatus that is used for aforesaid residue burning, they all can be used for existing equipment, particularly tangential heating boiler, and reduce the discharging of pollutant (mainly being nitrogen oxide and unburned carbon dust) significantly.
It is characterized in that oxygen-containing gas is ejected in the thermal region of described burner hearth according to of the present invention being used in the method for the boiler burning that comprises burner hearth and injector, and cycle gas is ejected into simultaneously in the thermal region of burner hearth from the residue of refining petroleum.
What be close to burner is an eddy-currents, that is, make burning gases center on the vertical axis rotation, transforms fully to guarantee them, and does not leave unburnt.Be ejected in the very hot zone of burner hearth, because of the decomposition of unburned carbon ash has been guaranteed the residue Pintsch process and changed into to be easy to burn and pollute less basic compound (CO, H 2, CH 4, CO 2).This method is applied to tangential heating boiler especially.
Spray in the time of cycle gas motion is joined in the air-flow of oxygen-containing gas, thereby impel described gas to be penetrated in the burner hearth, particularly be penetrated in the thermal region of cyclone.Spraying cycle waste gas also be easy to make combustion product that the residue cracking obtains in burner hearth evenly, thereby prevented that waste gas from temperature peak occurring near the heat exchanger that is arranged at above the combustion zone.The increase of nitrogen oxide in the thermal region (NOx) growing amount is by the low growing amount compensation of nitrogen oxide, and this is because use segmentation air or segmentation fuel to carry out sectional combustion.
According to characteristics, spray the influence of the injector of the corner be subjected to being arranged on burner hearth.Eject position will be as the function of the character for the treatment of combustion residue and is determined.One or more jetting heights can be set like this: the function that decomposes as the expectation of the nitrogen oxide that obtains in the face of the function of the peak temperature in the burner hearth of the fuel injector of barge arrangements and the sectional combustion that produces as combining by injection air and fuel and spraying cycle waste gas, oxygen and residue.
According to second configuration, spray the influence that is subjected to the injector on the burner hearth sidewall.
According to characteristics of second configuration, injector is in the centre of each sidewall of burner hearth.
In the modification of second configuration, injector is on four walls.
In another modification of second configuration, injector is on two relative walls.
According to the device that is used for gas is ejected into boiler furnace of the present invention, it is characterized in that it is installed in the exhaust gas recirculation pipeline, and comprise coaxial gas injection tube.This two is sprayed to combine and formed the thermal transition zone.These devices can be installed in a plurality of positions in the boiler furnace.
According to characteristics, this device is basically perpendicular to the wall of burner hearth in horizontal plane.This device in horizontal plane position, gradient and depart from the function that is suitable for as boiler construction, infiltrate in the heat burning whirlpool zone thereby impel.Therefore, backflow waste gas supply pipe can be crooked, and it causes extra, the rotation of approximate horizontal ground of inlet flow, thereby produce or aggravated around the rotating flow of the approximate vertical axis that is back to the waste gas in the burner hearth.
According to another characteristics, this device tilts towards the bottom of burner hearth approximate vertical.The angle of inclination is preferably less than 45 °.
According to second characteristics, this device comprises cooling circuit.The temperature at injection apparatus tip makes and must cool off it.
According to the 3rd characteristics, this installs by gas cleaning, to prevent that it is because of the obstruction that becomes of the dust from burner hearth.
According to the 4th characteristics, this device is retractible.Therefore, can in boiler work, keep in repair.
According to the 5th characteristics, this device comprises the some flame that impels the residue spontaneous combustion.
Description of drawings
From the following description that only provides as example, will understand the present invention better in conjunction with the accompanying drawings, in the accompanying drawing:
-Fig. 1 is the vertical cross-section diagram according to boiler of the present invention,
-Fig. 2 is the sectional view according to boiler of the present invention,
-Fig. 3 is the detailed sectional view of injector according to the present invention at eject position,
-Fig. 4 be Fig. 3 injector the detailed sectional view of retracted position and
-Fig. 5 is the detailed sectional view of playpipe.
The specific embodiment
In Fig. 1, boiler 1 comprises burner hearth 2, and the fuel 3 that is centered on by hot-air 4 supplies in this burner hearth 2.Injector 5 injection of oxygen or oxygen-containing gas 50, residue 51 and cycle gas 52 (suitable time).Cooling fluid 53 such as water flows so that it is cooled off in injector 5.Injector 5 is arranged on the height place of the thermal region 20 of burner hearth 2.Extra air sprays via injector 6, with the realization sectional combustion, thus the discharging of minimizing nitrogen oxide, injector 6 is positioned at the top of injector 5, makes the time that waste gas stopped between two injector height 5 and 6 0.2 second to 5 seconds.
Fig. 2 the height place of thermal region 20 from above the boiler 1 of Fig. 1 is shown.Fuel 3 and hot-air 4 spray in the corner of boiler 1.In this modification, injector 5 is positioned at the centre of the sidewall 21 of burner hearth 2, but also can be positioned at corner.Fuel 3 injection around the corner produces the whirlpool 200 of vertical axis, and residue 51 and gas 50 advance towards this whirlpool 200.
Injector 5 is shown specifically in Fig. 3, and it comprises supply pipe 500, the pipe 510 that is used for residue 51 that is used for oxygen (or oxygen-containing gas) 50, the return duct 531 that is used for the supply pipe 530 of cooling fluid 53 and is used for described cooling fluid 53.Cycle gas 52 arrives via pipe 520.Injector 5 is penetrated in the thermal region 20 to impel residue 51 with downward-sloping less than 45 ° angle.Being combustion zone 23 below the zone 22 that is used for residue after gasifying 51, is after-combustion zone 24 above zone 22.
Be discharged into the playpipe 54 in the burner hearth 2 shown in Fig. 5, it is made of four coaxial cylinders; Residue 51 flows in central cylinder 540, oxygen rich gas 50 flows between the cylinder 541 of cylinder 540 and vicinity, cooling fluid 53 flows between cylinder 541,542 and 543, thereby in pipe 54, form a backhaul, outflow is to be easy to cooling off backflow between innermost cylinder 541 and 542 between outmost cylinder 542 and 543.
Waste gas 52 arrives via pipe 520, and enters the pipe 521 of injector 5, is imported into thus (referring to Fig. 3) in the burner hearth 2.
Fig. 4 illustrates the injector 5 that is in retracted position, and this assembly comprises pipe 54 and is withdrawn into pipe 530,531,510 and 500 in the supply pipe 521 of waste gas 52, makes the assembly of this injector 5 in use to keep in repair.
Next manner of execution is described.Fuel 3 and hot-air 4 are ejected in the bottom 23 of burner hearth 2.Burning begins gradually, and the zone 20 of burner 30 tops is the hottest zones.Residue 51 and oxygen rich gas 50 are ejected in this zone 20 residue 51 cracking and be decomposed into flammable basic compound in zone 20.Cycle gas 52 via injector 5 time coaxial injection motion is joined the air-flow and the residue 51 of oxygen (or oxygen rich gas) 50, thereby impel residue 51 and gas 50 to be penetrated in the cyclonic current zone 200 of vertical axis of burner hearth 2, and produce the thermal transition zone that promotes residue 51 burnings.
The quantity that is installed in the injector 5 in the burner hearth 2 determines as the function of the character for the treatment of combustion residue 51.Injector can be arranged on one or more height, the function of the hot-fluid that is allowed as wall 21, and as the function of the necessary condition of the smoothed temperature peak value in the waste gas at waste gas bump heat exchanger bundle 7 places.
The gradient of injector 5 and departing from vertical direction thereof less than 45 °.
Spraying system 5 comprises the some flame that is used to impel residue 51 spontaneous combustions.

Claims (13)

1. be used for comprising burner hearth (2) and injector (5,30,6) burning is from the method for the residue of refining petroleum (51) in the boiler (1), it is characterized in that cycle gas (52), described residue and oxygen-containing gas (50) are ejected in the burner hearth (2) simultaneously in the thermal region (20) of described burner hearth (2).
2. according to the method for claim 1, it is characterized in that, spray the influence of the injector (5) of the corner be subjected to being arranged on burner hearth (2).
3. according to the method for claim 1, it is characterized in that, spray the influence of the injector (5) on the sidewall (21) that is subjected to being arranged on burner hearth (2).
4. according to the method for claim 3, it is characterized in that injector (5) is arranged on the centre of the sidewall (21) of burner hearth (2).
5. according to the method for claim 4, it is characterized in that injector (5) is arranged on four walls (21).
6. according to the method for claim 4, it is characterized in that injector (5) is arranged on two relative walls (21).
7. be used for realizing according to the device in each the burner hearth (2) that gas (5) is ejected into tangential heating boiler (1) of method of aforementioned claim, it is characterized in that, described device is installed in the pipeline (521) of waste gas (52) that are used for refluxing, and comprise coaxial gas injection tube (540,541,542,543).
8. according to the device of claim 7, it is characterized in that described device is arranged in the horizontal plane perpendicular to the wall (21) of burner hearth (2).
9. device according to Claim 8 is characterized in that, described device tilts towards the bottom vertical of burner hearth (2).
10. according to the device of claim 7 or claim 8, it is characterized in that described device comprises cooling circuit (53,530,531,541,542,543).
11., it is characterized in that described device is by gas cleaning according to each device among the claim 7-9.
12., it is characterized in that described device is retractible according to each device among the claim 7-9.
13., it is characterized in that described device comprises a flame according to each device among the claim 7-9.
CN2005800215017A 2004-04-30 2005-04-28 Method for burning refining residues Expired - Fee Related CN1977128B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR0450840A FR2869673B1 (en) 2004-04-30 2004-04-30 PROCESS FOR COMBUSTION OF REFINING RESIDUES
FR0450840 2004-04-30
PCT/FR2005/050284 WO2005111498A1 (en) 2004-04-30 2005-04-28 Method for burning refining residues

Publications (2)

Publication Number Publication Date
CN1977128A CN1977128A (en) 2007-06-06
CN1977128B true CN1977128B (en) 2011-11-09

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CN2005800215017A Expired - Fee Related CN1977128B (en) 2004-04-30 2005-04-28 Method for burning refining residues

Country Status (7)

Country Link
US (1) US20110146546A1 (en)
EP (1) EP1740886A1 (en)
CN (1) CN1977128B (en)
CA (1) CA2564639C (en)
FR (1) FR2869673B1 (en)
MX (1) MXPA06012429A (en)
WO (1) WO2005111498A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102563634B (en) * 2011-11-14 2015-02-18 上海锅炉厂有限公司 Coal dust thickness-thinness separating and distributing structure of single-fireball eight-corner direct-flow burner
GB2531010A (en) * 2014-10-07 2016-04-13 Linde Ag Incineration of waste
JP6461588B2 (en) * 2014-12-12 2019-01-30 川崎重工業株式会社 Combustion system
JP2017190920A (en) * 2016-04-14 2017-10-19 日工株式会社 Burner device and combustion method for the same
CN110925744B (en) * 2019-12-11 2021-09-17 中国能源建设集团广东省电力设计研究院有限公司 System for recycling bypass flue gas heat from heat conducting oil of cold flue gas recirculation unit and control method

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD127936A1 (en) * 1976-09-03 1977-10-19 Paul Fischer PROCESS FOR BURNING SLEEPING FROM WASTEWATER CLEANING
US4878442A (en) * 1988-06-17 1989-11-07 The United States Of America As Represented By The Department Of Energy Nox control for high nitric oxide concentration flows through combustion-driven reduction
US5020454A (en) * 1990-10-31 1991-06-04 Combustion Engineering, Inc. Clustered concentric tangential firing system
US5129333A (en) * 1991-06-24 1992-07-14 Aga Ab Apparatus and method for recycling waste
DE4140063A1 (en) * 1991-12-05 1993-06-09 Hoechst Ag, 6230 Frankfurt, De BURNER FOR THE PRODUCTION OF SYNTHESIS GAS
US5217363A (en) * 1992-06-03 1993-06-08 Gaz Metropolitan & Co., Ltd. And Partnership Air-cooled oxygen gas burner assembly
DE19806823C2 (en) * 1998-02-18 1999-12-09 Loesche Gmbh Device and method for the combustion of fuels containing vanadium
US6325002B1 (en) * 1999-02-03 2001-12-04 Clearstack Combustion Corporation Low nitrogen oxides emissions using three stages of fuel oxidation and in-situ furnace flue gas recirculation
US6314896B1 (en) * 1999-06-10 2001-11-13 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Method for operating a boiler using oxygen-enriched oxidants
US6260491B1 (en) * 1999-09-13 2001-07-17 Foster Wheeler Corporation Nozzle for feeding combustion providing medium into a furnace
US6699030B2 (en) * 2001-01-11 2004-03-02 Praxair Technology, Inc. Combustion in a multiburner furnace with selective flow of oxygen
US6702569B2 (en) * 2001-01-11 2004-03-09 Praxair Technology, Inc. Enhancing SNCR-aided combustion with oxygen addition
US7185595B2 (en) * 2001-09-07 2007-03-06 Air Products & Chemicals, Inc. Method for largely unsupported combustion of petroleum coke
US7484956B2 (en) * 2003-09-16 2009-02-03 Praxair Technology, Inc. Low NOx combustion using cogenerated oxygen and nitrogen streams

Also Published As

Publication number Publication date
CA2564639C (en) 2012-12-04
CA2564639A1 (en) 2005-11-24
WO2005111498A1 (en) 2005-11-24
US20110146546A1 (en) 2011-06-23
MXPA06012429A (en) 2007-01-31
FR2869673A1 (en) 2005-11-04
EP1740886A1 (en) 2007-01-10
CN1977128A (en) 2007-06-06
FR2869673B1 (en) 2010-11-19

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Address after: Baden, Switzerland

Patentee after: ALSTOM TECHNOLOGY LTD

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Granted publication date: 20111109

Termination date: 20180428