• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    A method of fuel combustion in a cylindrical combustion chamber comprising, in said combustion chamber, a projection, from a burner, of a pulverulent solid fuel jet displaced by a transport air, and optionally a primary air flow, and a supply of an oxidizing gas in a direction of propagation so as to form a stream of oxidant gas around the jet of fuel projected by the burner, at a temperature causing a combustion of the fuel, the fuel jet solid having an axial projection component in the same direction as said direction of propagation of the combustion gas in the cylindrical combustion chamber and the ratio between the specific flow rate of the burner momentum and the specific flow rate of the combustion gas being equal to or less than 1.0 and greater than zero.
    公开号:BE1024784B1
    申请号:E2017/5460
    申请日:2017-06-28
    公开日:2018-07-02
    发明作者:Ziad Habib
    申请人:S.A. Lhoist Recherche Et Developpement；
    IPC主号:
    专利说明:

    (73) Holder (s):
    S.A. LHOIST RESEARCH AND DEVELOPMENT 1342, OTTIGNIES-LOUVAIN-LA-NEUVE Belgium (72) Inventor (s):
    HABIB Ziad 1630 LINKEBEEK Belgium (54) Method of combustion of fuel in a tubular combustion chamber (57) Method of combustion of fuel in a cylindrical combustion chamber, comprising, in this combustion chamber, a projection, from a burner, of a jet of pulverulent solid fuel displaced by transport air, and optionally of a primary air flow, and a supply of an oxidizing gas in a direction of propagation so as to form a current of oxidizing gas around of the jet of fuel projected by the burner, at a temperature causing combustion of the fuel, the jet of solid fuel having an axial component of projection in the same direction as said direction of propagation of the oxidant gas in the cylindrical combustion chamber and the ratio between specific flow rate of momentum of the burner and specific flow rate of momentum of the oxidant gas being equal o u less than 1.0 and greater than zero.

    AT
    CM
    BELGIAN INVENTION PATENT
    FPS Economy, SMEs, Middle Classes & Energy
    Publication number: 1024784 Deposit number: BE2017 / 5460
    Intellectual Property Office International Classification: F23C 3/00 F23D 1/02 F23D 99/00 Date of issue: 02/07/2018
    The Minister of the Economy,
    Having regard to the Paris Convention of March 20, 1883 for the Protection of Industrial Property;
    Considering the law of March 28, 1984 on patents for invention, article 22, for patent applications introduced before September 22, 2014;
    Given Title 1 “Patents for invention” of Book XI of the Code of Economic Law, article XI.24, for patent applications introduced from September 22, 2014;
    Having regard to the Royal Decree of 2 December 1986 relating to the request, the issue and the maintenance in force of invention patents, article 28;
    Given the patent application received by the Intellectual Property Office on 28/06/2017.
    Whereas for patent applications falling within the scope of Title 1, Book XI of the Code of Economic Law (hereinafter CDE), in accordance with article XI. 19, §4, paragraph 2, of the CDE, if the patent application has been the subject of a search report mentioning a lack of unity of invention within the meaning of the §ler of article XI.19 cited above and in the event that the applicant does not limit or file a divisional application in accordance with the results of the search report, the granted patent will be limited to the claims for which the search report has been drawn up.
    Stopped :
    First article. - It is issued to
    S.A. LHOIST RESEARCH AND DEVELOPMENT, Rue Charles Dubois 28, 1342 OTTIGNIES-LOUVAINLA-NEUVE Belgium;
    represented by
    GEVERS PATENTS, Holidaystraat 5, 1831, DIEGEM;
    a Belgian invention patent with a duration of 20 years, subject to the payment of the annual fees referred to in article XI.48, §1 of the Code of Economic Law, for: Fuel combustion process in a combustion chamber tubular.
    INVENTOR (S):
    HABIB Ziad, Rue Arthur Van Dormael 10, 1630, LINKEBEEK;
    PRIORITY (S):
    06/28/2016 BE 2016/5489;
    DIVISION:
    divided from the basic application: filing date of the basic application:
    Article 2. - This patent is granted without prior examination of the patentability of the invention, without guarantee of the merit of the invention or of the accuracy of the description thereof and at the risk and peril of the applicant (s) ( s).
    Brussels, 02/07/2018, By special delegation:
    B E2017 / 5460
    The present invention relates to a method of burning fuel in a cylindrical combustion chamber, comprising, in this combustion chamber,
    - a projection, from a burner, of a jet of pulverulent solid fuel displaced by transport air, and possibly of a primary air flow, and
    - a supply of an oxidizing gas in a direction of propagation of ίο so as to form a current of oxidizing gas around the jet of fuel projected by the burner, at a temperature causing combustion of the fuel.
    In the field of calcination of mineral rocks, in particular calcareous and dolomitic rocks, different types of ovens are used, including rotary ovens, tank ovens, and in particular straight annular ovens.
    These straight annular ovens use, for heating the material, upper and lower combustion chambers. The lower combustion chambers are originally designed to work with natural gas as fuel and it burns almost instantly,
    Now, it is becoming more and more desirable to be able to replace, in these ovens currently in service, the combustible gas with a less expensive fuel, in particular a solid pulverulent fuel of the coal, coke or lignite powder type, grape seeds. , olive pits, sawdust, etc.
    An example not in accordance with the invention of the burner is shown diagrammatically in an axial section in FIG. 3a and in perspective in FIG. 4a, the burner comprises a fuel duct 120 surrounded by a cylindrical sleeve 121 comprising a flared portion 127 towards the end of the burner nose ef comprising a plurality of holes 128. The cylindrical sleeve
    B E2017 / 5460
    121 forms with the conduit 120 an annular space through which passes a combustible gas 126. The sleeve 121 and the conduit 120 are provided in an external envelope 122 (shown in FIG. 3a, not shown in the figure
    4a) so that the nose of the conduit 120 protrudes from the flared portion 127 of the sleeve 121 and from the nose of the external envelope 122 t that the flared portion 127 of the sleeve is set back relative to the nose of the external envelope 122 Axial primary air 105 can circulate between a space formed by the external envelope 122 and the sleeve 121, as well as by the plurality of holes 128 on the flared part of the sleeve.
    ίο The supply of the burners in the lower combustion chambers of annular calcination ovens with such a solid pulverulent fuel proved, however, during experimental tests carried out by the applicant, hardly suitable. In fact, the combustion is incomplete, which leads to combustion of the unburnt no longer in the combustion chamber, but in the bed of material and even in the interior cylinder of the annular furnace, by which the hot smoke gases are recovered. This results in a deterioration in the quality of the cooked product (loss of reactivity) and in productivity (frequent stops of the oven to clean it). And we end up having to continue to use combustible gas in combination with pulverulent solid fuel to avoid these problems. The expected price reduction is thus greatly reduced,
    It should be noted that the lower combustion chambers of the annular straight ovens are small and short. They are designed for natural gas which burns instantly according to the law of "immediately mixed, immediately burned" of a homogeneous combustion (gas-gas combustion). In these chambers also the air necessary for combustion arrives premixed with recirculated smoke gases, which have a reduced oxygen concentration.
    When solid fuel is sprayed into the combustion chamber, the situation is different, we are faced with heterogeneous combustion (solid-gas) where the law of "immediately mixed, immediately burned" is no longer applicable. Burning time is much longer and depends very much
    B E2017 / 5460 factors such as particle size, reactivity of the solid surface, availability of oxygen near the solid surface.
    Simply replacing gaseous fuel with solid fuel in existing combustion chambers has therefore proven to be really problematic.
    In order to improve the combustion of solid fuel, mechanical devices have already been provided which force the solid fuel to mix more intimately with the oxidant (see for example BE 1015804 and EP2143998). However, such systems remain complicated and costly to manufacture and especially to maintain, they present non-negligible risks of malfunction, such as blockages, rapid wear of mechanical parts, etc.
    The object of the present invention is to remedy these drawbacks and therefore to propose a combustion method applicable in the combustion chambers of ovens, in particular of existing ovens, which is effective with consumption only of pulverulent solid fuel.
    To solve this problem, a combustion method has been provided as indicated at the beginning, in which the solid fuel jet has an axial projection component in the same direction as said direction of propagation of the oxidant gas in the cylindrical combustion chamber and wherein the ratio between specific flow rate of momentum of the burner and specific flow rate of momentum of the oxidant gas is 1.0 or less and greater than zero.
    The specific momentum flow rate is the measure of the force of a jet (eg burner jet or oxidant current) divided by the power of the burner.
    The specific flow rate of momentum of the burner used is calculated according to the following equation (1):
    Gax_brûleur ~ (Gmcs + Qmat) x Vinj / P + Qmap x Vap / P, where Qmcs ~ mass flow rate of solid fuel (kg / sec),
    Qmat - mass flow of transport air (kg / sec),
    Qmap ™ mass flow rate of primary air (kg / sec),
    B Ε2017 / 5460 of axial fuel injection (m / sec)
    Vap ~ axial injection speed of the primary air, and
    P - burner power (MW).
    The axial injection speed is calculated according to the following equation (2):
    For fuel
    Vinj ”Qvat / Sb, where
    Qvat ~ actual volume flow rate of the transport air (m 3 / sec), and Sb “cross section of the fuel injection pipe into the burner (m 2 ). primary air ίΖί
    Sap “cross section of the primary air injection pipe into the burner (m2)
    The burner power is calculated according to the following equation (3):
    P - Qmcs x PCI, where
    PCI - lower calorific value of the fuel (MJ / kg).
    The specific flow rate of momentum of the oxidizing gas is calculated according to the following equation (4):
    Gax_comburant ~ Qmgc x Vgc / P, where
    Qmgc - mass flow rate of oxidizing gas (kg / sec), and
    Vgc - axial speed of the oxidant gas around the solid fuel jet (m / sec).
    The axial speed of the oxidizing gas is calculated according to the following equation (5):
    Vgc ~ Qvgc / Scb, where
    Qvgc volume flow rate of the oxidizing gas (m 3 / sec), and Sch cross section of the combustion chamber (m 2 ).
    The basic principle in the design of the burners is that a burner must have a large momentum flow rate (injection speed x mass flow rate) sufficient for the central fuel jet to be able to suck the oxidant arriving at its periphery, thus forcing the fuel / oxidizer mixture, which accelerates combustion. The aerodynamics of a
    B E2017 / 5460 traditional design flame is therefore determined by the burner itself (see Figure 1}.
    On the contrary, the process according to the present invention is based on an aerodynamics which is determined by the oxidant arriving in the combustion chamber. The oxidizer here forces the fuel to enter its current by adapting the flow rate of momentum of the burner to that of the oxidant (see Figure 2), It is therefore no longer the fuel jet that is driving, it is the fuel which is entrained by the oxidizer. This results in an increased residence time of the fuel, with the effect of being able to use combustibleο a fuel only in a pulverulent solid form and to obtain total combustion of this fuel in the combustion chamber.
    To adapt this flow rate of movement of the burner, it is possible, for example, to provide for increasing the fuel injection section in the burner nose, which has the immediate effect of reducing the injection speed of the fuel while retaining unchanged your fuel and oxidant flow rates and the speed of the oxidant and what has no influence on the operation of the oven itself, This is a minor and easy modification of the burner nose, with immediate effect on the ratio claimed between the specific flow rates of momentum which is adapted to become equal to or less than 1.0. Preferably this ratio will be between 0.5 and 0.9.
    According to one embodiment of the method according to the invention, the cylindrical combustion chamber has first and second axial ends ef the jet of pulverulent solid fuel is projected by the burner from the first axial end of the combustion chamber towards the second axial end. Advantageously, the burner is arranged in an opening provided in the front wall of the first end of the combustion chamber. The solid fuel jet can thus come into contact with the oxidant over the entire length of the combustion chamber.
    According to the invention, the oxidizing gas is mainly a flue gas recirculated, for example from the calcination oven. This smoke gas can be enriched with oxygen, for example by adding air.
    B E2017 / 5460
    Avaretagsusement, te oxidant gas is fed tangentially into ia combustion chamber at said first end thereof, so as to form a helical stream of oxidant gas around the jet of fuel projected by the burner, This promotes the oxidant fuel5 mixture. It is of course also possible to provide that the oxidizing gas is supplied to the combustion chamber at said first end thereof, parallel to its axis and around the fuel jet projected by the burner. The propagation of the oxidizing gas must in any case follow a direction of propagation towards the downstream end of the combustion chamber.
    To further promote the fuel-oxidant mixture, provision may be made, according to the invention, for partial or total rotation of the fuel jet transported by transport air. This can for example be obtained by giving a rotational movement to the transport air, using guide vanes,
    The process according to the invention is intended to be preferably implemented in a lower combustion chamber of an annular straight furnace for calcining limestone or dolomitic rock,
    The present invention also relates to such a combustion chamber comprising, at a first axial end, a burner arranged to project a jet of pulverulent solid fuel into this chamber, and optionally an axial primary air flow, and a supply inlet for an oxidizing gas arranged so as to form a current of oxidizing gas in a direction of propagation around the jet of fuel projected by the burner, the burner being arranged to project the solid fuel according to an axial component of projection having the same direction as the direction of propagation of the current of oxidizing gas in the cylindrical combustion chamber, so as to allow the implementation of the method according to the invention. It also relates to a straight annular furnace for calcining limestone or dolomitic rock, comprising at least one such combustion chamber as well as to a straight annular furnace for calcining limestone or dolomitic rock, implementing a method according to the invention.
    B E2017 / 5460
    The invention will now be described in more detail with reference to the accompanying drawings given without limitation,
    Figure 1 schematically shows a projection not in accordance with the invention of a pulverulent solid fuel jet in an oven
    S conventional rotary.
    FIG. 2 schematically represents a projection according to the invention of a pulverulent solid fuel in a combustion chamber, for example of a straight annular calcination furnace,
    FIG. 3a represents a schematic view according to a longitudinal section of a burner not in accordance with the invention.
    FIG. 3b represents a view in axial section of a burner which can be used for implementing the method according to the invention,
    Figure 4a shows a schematic perspective view of a burner not according to the invention.
    FIG. 4b represents a schematic perspective view of an embodiment of a burner which can be used for implementing the method according to the invention.
    FIG. 4c represents a schematic perspective view of another embodiment of a burner which can be used for implementing the method according to the invention.
    FIG. 5 represents a view in axial section of a straight annular calcination furnace provided with lower combustion chambers implementing the method according to the invention.
    In the various drawings, the identical elements bear the same references.
    It is customary to use, in the combustion chambers of industrial rotary ovens, burners which are supplied only with pulverulent solid fuel. The conditions provided for the operation of burners of this kind, the power of which is 88 MW, in a rotary kiln with a flow rate of 11 ot / day are summarized in table 1 below.
    B E2017 / 5460
    Debit tco Speed(m / sec) Gax (N / MW) Oxidizer * ï 65808 7h 550 2.5 0.74 Air oftransport 22Ï27 mVh 50 60 6.10 Coal 9ÛG0 kg / h 50 60 2.28 Total burner 8.38 Gaxjarüleur / Gax ^ comburanl 11.29
    * The oxidizer in this case is Air.
    As you can see the specific flow rate of momentum of the burner (transport air - coal) is much higher than that of the oxidant.
    In Figure 1 this combustion chamber 1 is illustrated schematically. The fuel is sprayed by the burner 2 at a very high injection speed 3 and the injection cone 4 formed by the sprayed fuel io outside the burner nose has a very tapered shape, Thanks to this high injection speed 1e oxidizer 5, supplied around the fuel jet, is drawn into it,
    As can be seen from FIG. 5, a conventional annular straight furnace for calcining limestone or dolomitic rock comprises an outer cylinder 6 and an inner cylinder 7 forming an annular space 8 into which the material to be baked descends. The raw material is introduced from the top of the oven at 9 and the cooked product is discharged from the bottom at 10. The fuel is injected at two levels, through several upper 11 and lower 12 combustion chambers (from 4 to 8 chambers depending oven capacity). In general, 1/3 of the fuel is injected into the chambers 11 and 2/3 into the chambers 12. All of the smoke from the upper chambers 11 and part of the smoke from the lower chambers 12 is drawn upwards by a blower. draft 13, therefore against the current of the movement of the material charge. In this area there is a calcination against the current. The other part of the flue gases from
    B E2017 / 5460
    UT lower combustion chambers 12 is drawn downwards by a depression created at the return vents 14 provided in the inner cylinder 7, lower than the combustion chambers 12, this is the calcination zone by cocurrent, at the level smoke flues from the co-current calcination zone mix with the cooling air introduced at the bottom of the oven at 15. This mixture forms the recirculation fumes which. at 18, are recovered from the lower cylinder 7 and brought back to the lower combustion chambers 12 to become the oxidizing gas there. Through a conduit 17, this oxidizing gas 31 arrives at each of the chambers 12 tangentially to the axis of the chamber and therefore to the jet of the ίο burner 18 injected axially. Therefore, the oxidant gas 31 acquires a rotational movement which induces a centrifugal force pushing the oxidant gas 31 towards the walls of the cylindrical combustion chamber.
    Experimental tests were then carried out to apply to each of the combustion chambers of such a conventional annular calcination furnace is a supply of the burner only with pulverulent solid fuel,
    FIG. 3b represents an axial section of an embodiment of the burner according to the invention. The burner comprises a sleeve 21 comprising a central duct 20 through which the pulverulent solid fuel is supplied. The sleeve 21 further comprises at least one additional duct 23 through which 20 of the combustible gas 28 can be supplied when the furnace is ignited. , and only at that time. An external envelope 22 envelops the sleeve 21 and forms with it a space through which axial primary air 5 can be supplied to aid combustion. The external envelope 22 comprises a portion 19 whose internal diameter is gradually reduced towards the nose of the burner, and the sleeve comprises a portion 27 whose external diameter increases progressively towards the nose of the burner so as to reduce the space between the nose of the external casing 22 and the nose of the sleeve 21. This reduction d The space between the outer casing 22 and the sleeve makes it possible to increase the speed of injection of the axial primary air 5 into the combustion chamber without having to provide a high flow rate of axial primary air. The nose of the outer casing 22, the nose of the sleeve 21, the nose of the central duct 20 and the nose of said at least one additional duct 23 pass through a plane orthogonal to the axis 30 of the burner.
    B E2017 / 5460
    FIG. 4b represents a perspective view of a first embodiment of the burner according to the invention. The sleeve 21 comprises a central duct 20 through which the pulverulent solid fuel is brought. The sleeve 21 further comprises an additional conduit 23 forming a thin annular space, through which combustible gas 26 can be supplied at the time of ignition of the furnace, and only at that time. An outer jacket 22 (not shown in Figure 4b) wraps the sleeve 21 and forms a space through which axial primary air 5 can be supplied to aid combustion.
    1Q Figure 4c shows a perspective view of another embodiment of the burner according to the invention. The sleeve 21 comprises a central duct 20 through which the pulverulent solid fuel is brought. The sleeve 21 further comprises a plurality of additional conduits 23 distributed around the central conduit 20, these additional conduits 23 through which gas
    X5 fuel 26 can be supplied when the oven is switched on, and only at that time. An external envelope 22 (not shown in FIG. 4c) envelops the sleeve 21 and forms a space through which axial primary air 5 can be supplied to aid combustion.
    According to other possible embodiments of the burner, a reduction in space between the sleeve 21 and the outer casing 22 can be achieved only by reducing the internal diameter of the casing 22 at the level of the burner nose and keeping the external diameter of the sleeve 21 constant, or alternatively by increasing the external diameter of the sleeve 21 at the nose of the noisemaker while keeping the internal diameter of the envelope 22 constant.
    This reduction in space between the sleeve 21 and the casing makes it possible to provide a higher primary air injection speed at the outlet of the burner.
    According to another possible embodiment of the burner, the internal diameter of the casing 22, the external diameter of the sleeve 21 and the space between the sleeve 21 and the external casing remain constant. In this case, the axial primary air flow or the volume of the sleeve 21 or the volume of the interior of the casing 22 are adapted to allow the axial primary air to exit at a predefined speed at the nose of the burner.
    B E2017 / 5460 w
    FIG. 5 represents a diagram of an annular oven and includes a representation of an embodiment of a cylindrical combustion chamber 12 according to the invention. In this embodiment, the combustion chamber comprises an inlet forming the casing 22 of the burner 18 and the axis 30 of the burner is preferably located in the axis 30 'of the cylindrical combustion chamber 12, The combustion chamber 12 further includes an oxidizing gas inlet 31 located tangentially to the axis 30, 30 'of the burner and of the cylindrical combustion chamber, as described above. The combustion gases are then evacuated from the combustion chamber by a pipe ίο The conditions provided for the operation of a burner as described using the example in FIG. 3b, the power of which is 1.13 MW, in a ring furnace with 4 lower combustion chambers and whose lime flow rate is 1501 / day, are summarized in Table 2 below.
    is Table 2
    Debit f (° C) | Speed (m / sec) Gax (M / MW) Oxidizer * ~~ lO995 n / F 700 [6.1 5.99 Axial primary air 700 m 3 / h 200 ; 34 1.89 Transport air 199m 3 / h 50 i 80 3.19 Coal 185 kg / h 50 i 80 2.73 Total burner 7.81 GaxJsrûleur / Gaxjcomburanî 1.30
    The oxidizer is in this case formed of recirculation gases.
    The injection speed of the fuel transported by air is obtained by passage through the duct 20 which has a section of 0.001 m 2 , The “force” of the burner, that is to say its specific flow rate of quantity of movement (primary axial air + transport air + coal) is still slightly greater than that of the oxidant, but it is insufficient to suck the oxidant into the fuel. It is not to be compared with that of the rotary kiln described above. And therefore we observe an unsatisfactory combustion with an oven with the
    B E2017 / 5460
    Provision has now been made, for an annular calcination furnace having the same lime flow rate of 150 t / day and provided with identical lower combustion chambers with burners of the same power, to reduce the specific flow rate of momentum of the burner, on the contrary of what the skilled person would have imagined on the basis of his knowledge. The new conditions applied are those indicated in Table 3.
    * The oxidizer is in this case formed of recirculating gases.
    As can be seen, only the injection speed of the solid powdery fuel displaced by the transport air was changed, to almost half of its value. Such a modification could be obtained by adapting the section of the duct 20, to a value of 0.002 m 2 . This minor modification induced a ratio between the specific flow rate of the momentum of the burner and the specific rate of the momentum of the oxidant to be much less than 1,
    Surprisingly, it was found that this simple modification gave rise to a flame, initiated very quickly, as quickly as with natural gas, and above all that, now, it was the fuel which was sucked into the helical current of the oxidizing gas.
    This phenomenon is shown schematically in the figure
    2. Given its low injection speed 3, the fuel projected by the burner 2 forms a more open projection cone 4 and it is also sucked into the stream of oxidizing gas which becomes the engine.
    B E2017 / 5460
    An identical experiment was carried out on a burner, the power of which is 1.81 MW, in a straight annular furnace provided with 5 combustion chambers and whose flow rate is 3001 / day. The operating conditions with a burner whose cross section of the fuel supply duct is
    0.001 m 2 are given in table 4.
    Table 4
    Debit TfC) Speed (m / sec) Gax (N / MW) Oxidizer * Ï7502m ¥ = 700 6.2 8.13 Axial primary air Ï4Q0 nr / h 200 34 1.89 Transport air 318 m 3 / h 50 60 3.19 Coal 236 kg / h 50 60 2.73 Total burner 7.81 Gaxbrûieur / Gaxcomburanf 1.27
    * The oxidizer is in this case formed of recirculating gases.
    Ceο This result was found to be unsatisfactory for obtaining a satisfactory fuel-oxidant mixture in the combustion chamber and therefore total combustion of the pulverulent solid fuel therein.
    By modifying the injection speed of the fuel, by enlarging the cross section of the injection pipe to 0.002 m 2 , the conditions given in Table S below are obtained:
    Table 5
    Debit τ rc) Speed(m / sec) Gax (N / MW) Oxidizer * Ï75ÏÏ2 mP / h 700 :::: 6.2 6.13 Axial primary air 14Ö0 m7h 200 34 1.89 Transport air 318 nr / h 50 35 1.86 Coal 296 kg / h 50 35 1.59 Total burner 5.34 Gaxjorû! Eur / Gax_comburant 0.87
    BE2017 / 5460 * The oxidizer is in this case formed by recirculating gases.
    This arrangement allows a drastically increased residence time of the particles in the combustion chamber and therefore oxygen is better available and combustion is complete inside the combustion chamber.
    It should be understood that the present invention is in no way limited to the embodiments indicated above and that many modifications can be made thereto without departing from the scope of the appended claims.
    ίο We can for example add a clean movement to the burner, either by adding rotation fins in the pulverulent solid fuel circuit, or by adding rotation fins to the transport air circuit or to the axial primary air circuit, or a combination of these measures. You can also add an additional air circuit at the periphery of the burner, which is rotated to help open the fuel spray cone in the chamber.
    It is also possible to inject the fuel directly into the stream of oxidizing gas, for example at the point of arrival thereof in the combustion chamber, but before it is put into rotation.
    It is also quite possible not to supply primary air to the burner, which can modify the values of the ratio claimed compared to those obtained with a burner in which primary air is supplied.
    In a burner without primary air, when a fuel jet is used at an injection speed Vinj equal to 15 m / sec, the claimed ratio can even become equal to 0.25. At a Vinj injection speed of 45 m / sec, it will then be 0.74.
    B E2017 / 5460
    权利要求:
    Claims (11)
    [1]
    1. A method of burning fuel in a cylindrical combustion chamber, comprising, in this combustion chamber,
    - a projection, from a burner, of a jet of solid fuel
    5 powder moved by transport air, and possibly by a primary air flow, and
    - a supply of an oxidizing gas in a direction of propagation so as to form a current of oxidizing gas around the jet of fuel projected by the burner, at a temperature causing combustion of the fuel, characterized in that the jet of solid fuel has an axial projection component in the same direction as said direction of propagation of the oxidant gas in the cylindrical combustion chamber, and in that the ratio between specific flow rate of momentum of the burner and specific flow rate of
    15 momentum of the oxidant gas is equal to or less than 1.0 and greater than zero,
    [2]
    2. Method according to claim 1, characterized in that the ratio between specific flow rate of momentum of the burner and specific rate of momentum of oxidant gas is between 0.25 and
    20 0.9.
    [3]
    3. Method according to either of claims 1 and 2, characterized in that the cylindrical combustion chamber has first and second axial ends and in that the jet of pulverulent solid fuel is projected by the burner from the first axial end of
    25 the combustion chamber towards the second axial end,
    [4]
    4. Method according to claim 3, characterized in that the oxidant gas is fed tangentially into the combustion chamber at said first end thereof, so as to form a helical stream of oxidant gas around the jet of fuel projected by the burner.
    [5]
    5. Method according to claim 3, characterized in that the oxidizing gas is supplied to the combustion chamber at said first
    B E2017 / 5460 end of the latter, parallel to its axis and around the jet of fuel projected by the burner,
    8. Method according to any one of claims 1 to 5, characterized in that it comprises a partial or total rotation of the jet of
    S fuel transported by transport air,
    [6]
    7, Method according to any one of claims 1 to 8, characterized in that it comprises a partial or total rotation of the primary air flow.
    [7]
    8, Process according to any one of claims 1 to 7, ίο characterized in that the oxidizing gas is a recirculated smoke gas.
    [8]
    9. Method according to any one of claims 1 to 8, characterized in that said combustion chamber is a lower combustion chamber of an annular straight furnace for calcining mineral rock.
    [9]
    10. A cylindrical combustion chamber comprising, at a first axial end, a burner arranged to project a solid powdery fuel into this chamber and a supply inlet for an oxidant gas arranged so as to form a stream of oxidant gas in a direction of propagation around the jet of fuel projected by the burner, characterized in that the burner is arranged to project the solid fuel
    20 along an axial projection component having the same direction as said direction of propagation of the gases in the cylindrical combustion chamber, this chamber being arranged for the implementation of the method according to any one of claims 1 to 9.
    [10]
    11, Annular straight furnace for calcining mineral rock,
    25 comprising at least one combustion chamber according to claim 10.
    [11]
    12. Straight annular furnace for calcining mineral rock, implementing a process according to any one of claims 1 to 11.
    B E2017 / 5460;
    CM
    B E2017 / 5460 t — S r ~ ä
    B E2017 / 5460
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    FR2683620A1|1993-05-14|Thermal enclosure for the treatment of industrial products and industrial lime kiln including such an enclosure
    WO2017129872A9|2017-09-28|Homogenised reaction method, such as lean-gas combustion, and devices implementing same
    FR3047300A1|2017-08-04|GASIFICATION PROCESS AND DEVICES FOR IMPLEMENTING THE SAME
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    FR3006038A1|2014-11-28|ASYMMETRIC ROTARY OVEN BURNER
    同族专利:
    公开号 | 公开日
    BE1024784A9|2018-07-24|
    EP3475609A1|2019-05-01|
    BE1024784B9|2018-07-30|
    FR3053102B1|2021-10-15|
    FR3053102A1|2017-12-29|
    WO2018002151A1|2018-01-04|
    EP3475609B1|2022-03-09|
    BE1023896B1|2017-09-06|
    BE1024784A1|2018-06-27|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    BE1015604A3|2002-07-17|2005-06-07|Schoppe Fritz|Method and device for increasing the stability of flame in fireplace coal fog.|
    US20060169181A1|2003-02-24|2006-08-03|Posco|Method and burner apparatus for injecting a pulverized coal into rotary kilns, method and apparatus for producing cao using them|
    EP2143998A2|2008-07-11|2010-01-13|Rheinkalk GmbH|Burner unit for pulverulent fuel|
    EP3805640A1|2019-10-09|2021-04-14|S.A. Lhoist Recherche Et Developpement|Combustion chamber for an annular vertical shaft kiln and process of combustion in such a combustion chamber|
    BE1028191B9|2020-04-07|2021-11-30|Lhoist Rech Et Developpement Sa|Lime or dolomite calcination process and annular upright furnace implemented|
    法律状态:
    2018-08-29| FG| Patent granted|Effective date: 20180702 |
    优先权:
    申请号 | 申请日 | 专利标题
    BE2016/5489|2016-06-28|
    BE20165489A|BE1023896B1|2016-06-28|2016-06-28|METHOD FOR FUEL COMBUSTION IN A TUBULAR COMBUSTION CHAMBER|
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