Classifications

• • 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
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23B—METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
  • F23B7/00—Combustion techniques; Other solid-fuel combustion apparatus
  • F23B7/002—Combustion techniques; Other solid-fuel combustion apparatus characterised by gas flow arrangements
  • F23B7/007—Combustion techniques; Other solid-fuel combustion apparatus characterised by gas flow arrangements with fluegas recirculation to combustion chamber
• • 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
• • 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
  • F23L2900/00—Special arrangements for supplying or treating air or oxidant for combustion; Injecting inert gas, water or steam into the combustion chamber
  • F23L2900/07001—Injecting synthetic air, i.e. a combustion supporting mixture made of pure oxygen and an inert gas, e.g. nitrogen or recycled fumes
• • 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
  • Y02E20/32—Direct CO2 mitigation

Definitions

• the present invention relates to a method for reducing the amount of flue gas from combustion systems operating in the usual temperature range from 850 to 1100 ° C. and with excess oxygen by supplying oxygen.
• DE-A-40 26 245 discloses a process for the thermal treatment of wastes and residues, in which pure oxygen without dilution is used as the oxidizing agent, the aim being to melt the mineral constituents and thus to glaze them to separate and store the form or to recycle it. It is therefore necessary to work with temperatures of at least 1200 to 1400 ° C, preferably even temperatures of 1600 ° C. Conventional incinerators are unsuitable for such high temperatures.
• the method according to the invention allows for the first time to separate these two tasks from one another and to reduce the amount of flue gas by about 70%, so that flue gas cleaning can be carried out much more simply and efficiently, since the flue gases no longer contain the considerable amounts of atmospheric nitrogen as ballast
• the acidic constituents to be removed subsequently by the flue gas cleaning such as SO / SO 3 , HCl and HF, are present in higher concentrations and can therefore be removed more easily and efficiently.
• a particular advantage of the method according to the invention is that all conventional firing and boiler systems can be used.
• the downstream flue gas cleaning systems can, however, be dimensioned much smaller or, if they already exist in the usual dimensioning, they can be operated more economically and ecologically.
• the amount of oxygen admixed to the cooled partial flow of the exhaust gases is controlled by the oxygen content after the furnace and upstream of the boiler, which is measured in the usual way and is desired for the respective combustion material.
• the amount of recirculated and cooled exhaust gases is controlled according to the invention by the temperature measured in the boiler in the usual way.
• the amount of this partial flow is between 60 and 90% of the exhaust gases, while 10 to 40% of the flue gas cleaning is supplied. If desired, the ratio of these partial flows can be varied, especially if different wastes or fuels with different calorific values are used.
• the method according to the invention it is entirely possible to add the oxygen to only a partial stream of the recirculated cooled exhaust gases, while the main quantity of the recirculated cooled exhaust gases is only circulated.
• this measure permits easier and more reliable mixing of the recirculated cooled exhaust gases with the admixed oxygen and, on the other hand, the targeted introduction of oxygen to the material to be burned.
• the exhaust gas stream is dedusted before being returned to the furnace.
• the partial flow of the flue gases to be recirculated will preferably only be removed after the dedusting, mixed with oxygen and returned to the furnace.
• the amount of flue gas is reduced by this nitrogen content.
• Another advantage of the method according to the invention is that the efficiency of the overall system is significantly increased, since the lower amounts of flue gas also result in a reduction in energy losses due to exhaust gases.
• there is better heat transfer in the boiler since the exhaust gases predominantly consist of C0 2 and H 0, which emit the energy more strongly than nitrogen.
• the formation of nitrogen oxides is completely avoided or suppressed to such an extent that it is not necessary to de-nitrogenize the flue gases.
• the method according to the invention can be used in practically all conventional firing and boiler systems, in particular in those with a grate furnace, rotary tube furnace or with burner systems.
• High-calorific and low-calorific wastes and fuels such as garbage can thus also be used, since it is now possible for the first time to provide the oxygen required for the combustion regardless of how much gas must be made available as a coolant in order to Avoid excessive temperatures.
• the amount of flue gas is reduced to a maximum, since the flue gases only contain the optimally required excess amount of oxygen in addition to the combustion product CO 2, H 0 and the oxidizable impurities.
• the air nitrogen previously carried as ballast is no longer contained in the smoke gases produced according to the invention.
• Acidic impurities such as S0 “, HCl, HF can be used in the usual way Remove way. If necessary, denitrification can be dispensed with entirely.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chimneys And Flues (AREA)
• Treating Waste Gases (AREA)

Applications Claiming Priority (4)

Publications (1)

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ID=25925377

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (6)

• 1994
  • 1994-04-14 WO PCT/EP1994/001153 patent/WO1994025801A1/de active Application Filing
  • 1994-04-27 TW TW083103816A patent/TW247927B/zh active

Patent Citations (6)

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