FR2483452A1 - PROCESS FOR PURIFYING REACTION PRODUCTS - Google Patents

Abstract

THE INVENTION CONCERNS A PROCESS FOR DEPURING REACTION PRODUCTS, COMING FROM THE COMBUSTION OF MATERIALS CONTAINING IMPURITIES, BY ADDITION OF PRODUCTS COMBINING THESE IMPURITIES, IN WHICH THE TEMPERATURE INDISPENSABLE TO THIS COMBINATION IS MAINTAINED BY ALLOCATING PART OF THE CHEREE BY COMBUSTION WITH CURRENTS OF HEAT-ABSORBING MATERIAL, INTRODUCED DIRECTLY INTO THE COMBUSTION ZONE, AND IN WHICH THE MIXING RATE OF THE PRODUCTS TAKING PART IN THE REACTION, ESSENTIAL FOR THE COMBINATION OF IMPURITIES, IS OBTAINED BY DIRECT RELATION TO THESE ADDITIONAL PRODUCTS TO FUEL AND OR TO COMBUSTION AIR. THE PROCESS ALLOWS A MORE RATIONAL AND MORE INTENSIVE USE OF THE ADDITIONAL PRODUCTS.

Description

_C nr-ernte invention con1cerie you purifying process tie 'zodui * s ie

  reaction caused by comrhus-tion to L :. range of fuels with high calorific value

  contains: 'nt impurities such as compounds of -

  sulfur, chlorine and fluorine, by addition, in the

  hearth, of adducts combining these impurities.

  Methods are known which make it possible to carry out the

dry ration of reaction products from the combustion of fuels containing impurities such as fuel, chlorine and fluorine. In these proceedings, the

  produced from sdcition combining impurities are in-

  products in the home in various ways.

  According to a first known method, the procedure is carried out so that the adducts are introduced into the hearth in the form. sprayed, above the flame area, with air jets. The disadvantage of this

  known method is that the introduction rode of the pro-

  additive in the fireplace does not provide the combi-

nlaison of the impurities by the products of addition because the mixing energy, relatively reduced,

  air jets are not enough to obtain a metering rate

  Statistical line of the constituents associated with D, action. In addition, this mixture of constituents associated with the reaction takes place, for the most part, in temperature zones: e not ensuring optimal reaction conditions. In addition, the transparent residence time for the acceleration of the reaction is insufficient since the spraying of the products

  Addition usually takes place in reaction zones.

tion inert.

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  According to a second known method, one proceeds so that

  the adducts are mixed with the fuels

immediately before the introduction of these

  deny. Until now, the drawback of this process was that the adducts were subjected to the entire flame temperature spectrum, therefore had to pass through temperature zones rendering the adducts inactive. This is particularly the case for fuels with a high calorific value

necessarily producing flames at high temperatures

cross out. The object of the present invention is therefore to influence the temperature of the flame, in the combustion of fossil fuels with high calorific value, laying down conditions of temperature and mixing rate essential for the combination of harmful materials, so as to initiate this combination upon combustion by addition of gaseous adducts

or of fine grain size.

  This object is achieved, according to the invention, by a process in which, by transfer of part of the amount of heat released by the combustion of

  high calorific fuels at low cost

  rants of heat-absorbing material, introduced directly into the combustion zone, the temperature essential for the combination is maintained

  harmful substances, and in which, by providing

addition directly to the combustibl-e and / or to the combustion air, the rate of.language of the products associated with the reactivity is reached.

  the combination of harmful materials.

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  Many different types! Ourr'ont @be used cormme cou-

Rurts of heat-absorbing material to limit the temperature required for the reaction. According to a first embodiment of the method according to the invention, the stream of heat-absorbing material

  Their may be constituted by a cooled smoke gas

di, poor in oxygen, coming from the process of com

  *. cleanly said by external recycling, or a

foreign combustion process.

  The invention also makes it possible to use d4- gas.

  clnappement resulting from the operation of a turbine;, az simultaneously as an oxidizing agent and as a stream of material, e absorbing heat It will also be possible to use as a stream

heat absorbing material the flue gases

  c., keys, vacuumed in the 'lamme inside the hearth.

In accordance with the process of the invention, the adducts themselves may be used to form the stream of heat absorbing material. This will, in particular, be the case loz'sque, as in the addition of

  calcivm or dolomite carbonate, the energy required

  to be. The initiated calcination is drawn from the flame.

  The addition products will be made up of

  I, -: as reagents and metallic oxides, hy-

droxy-des and dea carbonates as well as by suspen-

We are concerned about these products.

  The aort of the absorbent material stream l ,. heat

  in the area of flame allows to reach the tem-

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  temperature and the mixing rate required for the reaction

  addition products contained in the fuel-

  target and / or in combustion air The application of the process of the invention is described below in detail, by way of nonlimiting example, with reference to the attached drawing, the single figure of which is a schematic longitudinal section. a pulverized coal burner

  The burner shown consists of a separate air tube

  dull 2, from a vehicle fuel air tube

and adduct 1, and an air tube supplied

  loping 3; this burner allows to create a zone of

  primary combustion 6 with a multiple air index

  tiple, between 0.6 and 1.1, of the stoichiometry.

  The burner is shaped so as to produce, internally

laughter of the flame, by determined processes (tour-

  wrap around air, é: anouissement co-

  burner mouth, isolation of internal air), an intensive reflux zone 5 from an already advanced combustion zone. The mixture

  air and fuel are quickly heated

  fD and inflamed. It is possible to act on this issue.

  heating and on this ignition by adjusting the ouanti-

internal air tee.

  The remainder of the combustion air, constituting the

  r-nt partial 4 (also known as a draft of air

  dué), is injected at the periphery, by a plurality of nozzles, so as to generate A e-xt-rieur of the y 2483452 :: e rmi..aie a? larxeone secondary or an area of fo; - ' very active! 7 ane les rartie $ de 7i.a surf-ce, i.héri = g'i l flc-u1, e, '... oign?: Es du coura.t air pe; rtiel, gases br. the cold sheets coming from the hearth are sucked up by ch ç u u ..... s s. at the flame temperature

  n is therefore abaicée and this contributes to influence-

  c'ncer favorably the unfolding:; e the reaction between the -, adSition product and harmful substances

carbonated.

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Claims (6)

  1. Process for the purification of reaction products generated   from flame combustion of fuels   high calorific value containing impurities- tees such as sulfur, chlorine and fluorine compounds, by adding, in the hearth,   addition tubes combining these impurities, laughed in that, by transfer of part of the quantity of heat released by the combustion of fuels with high calorific value to   streams of heat absorbing material, products directly in the combustion zone,   maintaining the temperature essential for com-   harming harmful substances, and in that, by adding additives directly to   combustibles and / or combustion air, dye the mixing rate of products associated with the reaction essential to the combination of harmful materials 2. Method according to Claim 1, characterized in   what the flow of absorbent material of the cha-   consists of a cooled flue gas,   poor in oxyEene, from the process of bustion proper by external recycling, or   of a foreign combustion process.   3. Method according to Claims 1 and 2, character-   that the exhaust gas is coming from the operation of a gas turbine is used if-   simultaneously as an oxidizing agent and as a amount of heat absorbing material. * 7 2483452 4. Method according to claim 1, characterized in that, as a stream of heat absorbing material, the gases of recycled smoke, drawn into the flame inside the fireplace. 5. Method according to the claims. 1, 2, 3 and 4, characterized in that   that the adducts consist of reactive gases and metal oxides, hydroxides and carbonates as well as by aqueous suspensions of these products. 6. Method according to claim 5, characterized in that the addition products are simultaneously used to constitute a   stream of heat absorbing material. e