Combustion chamber

Abstract

The invention relates to a combustion chamber (100) comprising: • a first chamber (120); • an intermediate chamber (130) comprising a convergent chamber (131) which comprises a first truncated cone (131P) defining a second volume, and comprising a divergent chamber (132) which comprises a second truncated cone (132P) defining a third volume; • a second chamber (140); the intermediate chamber (130) being inserted between the first chamber (120) and the second chamber (140) along a first axis (Z1) and being configured such that: • a first generatrix of the first truncated cone (131P) forms a first acute angle with a transverse plane orthogonal to the first axis (Z1); and • a second generatrix of the second truncated cone (132P) forms a second acute angle with the transverse plane which is greater than the first acute angle.

Description

[0001] COMBUSTION CHAMBER

[0002] Scope of the invention

[0003] The invention relates to the field of waste treatment.

[0004] In particular, the invention relates to the field of waste combustion.

[0005] State of the art

[0006] In prior art, we know of so-called "secondary" combustion chambers in a waste incineration line.

[0007] Such secondary combustion chambers are typically connected to an outlet of a primary combustion unit, for example a rotary kiln, and provide secondary combustion of the primary combustion fumes generated by burning waste in the primary combustion unit.

[0008] In the prior art, secondary combustion chambers are known to be cylindrical in shape and of sufficient length to increase the residence time of combustion fumes in the secondary combustion chamber.

[0009] However, such a geometry has the disadvantage of resulting in a non-homogeneous temperature distribution in the secondary combustion chamber.

[0010] This results in an accumulation of incomplete combustion by-products in the form of ash, which increases the fouling rate in the secondary combustion chamber, and consequently increases maintenance costs and the risk of equipment failure.

[0011] To limit these disadvantages, it is known in the prior art to inject auxiliary fuels into the secondary combustion chamber in an arrangement that promotes the formation of a turbulent helical flow by means of burners.

[0012] However, when the system is operating at high capacity, this turbulent helical flow is dominated by the flow of combustion fumes entering the secondary combustion chamber, which has the disadvantage of creating preferential passages that reduce the residence time of a large part of the combustion fumes in the secondary combustion chamber.

[0013] In addition, the corrosive environment of the secondary combustion chamber increases the risk of air leaks, which imposes sub-stoichiometric operating conditions on the burners, reducing flow turbulence and combustion efficiency and increasing the risk of fouling, resulting in high maintenance costs and requiring frequent technical shutdowns to implement procedures for cleaning ash accumulated in the secondary combustion chamber.

[0014] The invention aims at least to limit the aforementioned drawbacks. Summary of the invention

[0015] According to a first aspect, the invention relates to a combustion chamber comprising a volume intended to receive combustion fumes, the volume comprising a first, a second, a third and a fourth volume communicating fluidly with each other, and comprising • a first chamber comprising a first chamber wall delimiting the first volume, and comprising an inlet for receiving primary combustion fumes into the first volume;

[0016] • an intermediate chamber comprising a converging chamber including a first truncated cone delimiting the second volume, and comprising a diverging chamber including a second truncated cone delimiting the third volume;

[0017] • a second chamber comprising a second chamber wall delimiting the fourth volume, and comprising an outlet for evacuating secondary combustion fumes generated by combustion of primary combustion fumes in the combustion chamber;

[0018] the intermediate chamber being interposed between the first chamber and the second chamber along a first axis, the converging chamber converging along the first axis in a direction from the first chamber to the diverging chamber and said diverging chamber diverging along the first axis in said direction, the intermediate chamber being configured such that:

[0019] • that a first generatrix of the first truncated cone forming a first acute angle with a transverse plane orthogonal to the first axis, • that a second generatrix of the second truncated cone forming a second acute angle greater than the first acute angle with said transverse plane.

[0020] One benefit is to promote the formation of a turbulent flow by increasing the axial velocity of the combustion fumes linked to the progressive reduction of the cross-section through which said fumes pass into the second volume, which improves the mixing of the combustion fumes and the homogeneity of the temperature distribution.

[0021] Another benefit is to promote a longer residence time of combustion fumes in the combustion chamber, by reducing the axial velocity of the combustion fumes and increasing their tangential velocity in the third volume, which has the effect of improving combustion efficiency.

[0022] Thus, the fact that the second acute angle is greater than the first acute angle allows for a sufficient residence time of the turbulent flow in the combustion chamber in order to promote complete combustion of the combustion fumes.

[0023] According to one embodiment, a first portion of the second truncated cone is located on a first side of a first longitudinal plane comprising the first axis, and a second portion of the second truncated cone and the outlet of the second chamber are located on a second side of the first longitudinal plane separating the first side from the second side, the first portion of the second truncated cone comprising the second generatrix and the second portion of the second truncated cone comprising a third generatrix forming a third acute angle less than the second acute angle with the transverse plane.

[0024] This embodiment helps to limit fouling of the combustion chamber by reducing the formation of recirculation zones which cause ash deposits on the inner walls of the divergent chamber, while promoting the flow of combustion fumes towards the outlet of the second chamber.

[0025] According to one embodiment, a first portion of the second chamber wall is located on the first side of the first longitudinal plane, and a second portion of the second chamber wall is located on the second side of the first longitudinal plane and connects the second truncated cone to the outlet of the second chamber, the second portion of the second chamber wall forming, in a second longitudinal plane comprising the first axis and being orthogonal to the first longitudinal plane, a fourth acute angle less than the third acute angle with the transverse plane.

[0026] This embodiment helps to guide combustion fumes towards the outlet of the second chamber, while limiting the formation of recirculation zones in the combustion chamber.

[0027] This method of implementation therefore makes it possible to improve combustion efficiency and limit fouling of the combustion chamber.

[0028] According to one embodiment, the second portion of the second chamber wall forms, from the diverging chamber to the exit, in the second longitudinal plane and with the transverse plane, a plurality of successive fourth acute angles less than the third acute angle, and whose respective measures gradually decrease towards the exit of the second chamber.

[0029] This embodiment allows for a smooth flow of combustion fumes towards the outlet of the second chamber, while further limiting the formation of recirculation zones in the combustion chamber, through a progressive variation in the geometry of the wall of the second chamber connected to the outlet.

[0030] This embodiment also makes it possible to improve combustion efficiency and limit fouling of the combustion chamber.

[0031] According to one embodiment, the first acute angle is between 35° and 40°.

[0032] According to one embodiment, the second acute angle is between 50° and 60°.

[0033] According to one embodiment, the difference between the first acute angle and the second acute angle is between 15° and 20°.

[0034] According to one embodiment, the second truncated cone is attached to the first truncated cone. This embodiment improves the mechanical strength of the combustion chamber.

[0035] This embodiment also makes it possible to maintain a homogeneous flow of combustion fumes during the passage from the second volume to the third volume, which improves combustion efficiency.

[0036] According to one embodiment, the length of the second truncated cone along the first axis is greater than the length of the first truncated cone along the first axis.

[0037] According to this embodiment, the volume to be occupied by the combustion fumes in the third volume is larger and increases progressively along the first axis, which allows for a longer residence time of the combustion fumes in the combustion chamber, and therefore promotes complete combustion of these fumes.

[0038] According to one embodiment, the entrance to the first chamber comprises an opening formed in the first chamber wall and leading into the first volume, and further comprises a portion of a pipe extended along a longitudinal axis of the pipe so as to lead into said opening, said longitudinal axis being oriented along the pipe towards the opening and forming a fifth angle between 93° and 95° with the first axis so that said longitudinal axis has a positive component along the first axis in the direction from the first chamber to the second chamber.

[0039] One benefit of a positive component along the first axis is to guide the primary combustion fumes when injected into the first volume along a slightly upward trajectory along the first axis, which helps to promote faster combustion and to guide the combustion fumes towards the exit of the combustion chamber.

[0040] The value of the angle between 93° and 95° has the benefit of ensuring good mechanical strength between the portion of the pipe at the inlet and the first chamber wall.

[0041] According to one embodiment, the combustion chamber includes at least one burner configured to emit a flame along an emission axis oriented towards the first volume, an orthogonal projection of the emission axis of said burner onto the transverse plane forming a non-zero angle with an orthogonal projection onto said transverse plane of an axis of entry of the primary combustion fumes into the first volume.

[0042] This embodiment makes it possible to maintain a high temperature in the combustion chamber while optimizing the available volume that can be occupied by the combustion fumes, which promotes complete combustion of the combustion fumes.

[0043] According to one embodiment, the non-zero angle is approximately equal to 120°.

[0044] This embodiment also makes it possible to maintain a high temperature in the combustion chamber while promoting centrifugation of the combustion fumes in the first volume, and thus to optimize the available volume that can be occupied by these fumes and to further promote complete combustion.

[0045] According to one embodiment, the combustion chamber includes at least one injection lance configured to emit an auxiliary flow comprising at least one fuel along an injection axis oriented towards the first volume, an orthogonal projection of said injection axis onto the transverse plane forming a non-zero angle with an orthogonal projection onto said transverse plane of the inlet axis.

[0046] This embodiment makes it possible to increase the amount of material to be burned in the first volume while optimizing the available volume that can be occupied by combustion fumes, which further improves combustion efficiency.

[0047] According to one embodiment, the combustion chamber comprises a plurality of injection lances distributed around the first axis and each capable of emitting an auxiliary flow comprising at least one fuel along distinct respective injection axes each oriented towards the first volume.

[0048] This embodiment allows for a further increase in the quantity of material to be burned in the first volume while maintaining an optimized available volume that can be occupied by combustion fumes, thus further improving combustion efficiency.

[0049] According to one embodiment, orthogonal projections of the respective injection axes of at least two injection lances onto the transverse plane form an angle between them that is substantially equal to 90°.

[0050] This embodiment allows for further optimization of the available volume that can be occupied by combustion fumes in the first volume, thereby improving combustion efficiency.

[0051] According to one embodiment, the combustion chamber is a secondary combustion chamber of a waste incineration line.

[0052] This embodiment makes it possible to ensure more complete combustion of primary combustion fumes from the combustion of waste, for example hazardous, in a primary combustion chamber, for example a rotary kiln.

[0053] According to another aspect, the invention relates to a combustion device comprising the combustion chamber, and further comprising a primary combustion chamber delivering the primary combustion fumes.

[0054] Brief description of the figures

[0055] Other features and advantages of the invention will become apparent from the detailed description that follows, with reference to the attached figures, which illustrate:

[0056] Figure 1: A schematic perspective view of a combustion chamber according to the invention. Figure 2: A schematic representation of a longitudinal section of the combustion chamber, in an embodiment in which the slope of the second truncated cone is constant around the first axis.

[0057] Figure 3: A schematic representation of a longitudinal section of the combustion chamber, in an embodiment in which the slope of a portion of the second chamber wall connecting the second truncated cone to the outlet is greater than the slope of the second truncated cone.

[0058] Figure 4: A schematic representation of a longitudinal section of the combustion chamber, in an embodiment in which the slope of the second truncated cone is not constant around the first axis.

[0059] Figure 5: A schematic representation of a longitudinal section of the combustion chamber, in an embodiment in which the slope of a portion of the second chamber wall connecting the second truncated cone to the outlet gradually decreases along the first axis until the outlet of the second chamber.

[0060] Figure 6: A schematic representation of a longitudinal section of the combustion chamber, in an embodiment in which the primary combustion flue gas inlet axis forms a distinct angle of 90° with the first axis.

[0061] Figure 7: A schematic representation of a cross-section of the first chamber, in an embodiment in which the combustion chamber includes injection lances and burners.

[0062] Description of the invention

[0063] According to a first aspect, the invention relates to a combustion chamber 100.

[0064] As shown in Figure 1, the combustion chamber 100 comprises a first chamber 120, an intermediate chamber 130, and a second chamber 140 distributed along a first axis Zi.

[0065] According to one embodiment, the combustion chamber 100 is installed so that the first axis Zi is a vertical axis, i.e. an axis of gravitational force at the level of the combustion chamber 100.

[0066] According to one embodiment, the combustion chamber 100 is self-supporting.

[0067] It includes, for example, a support in contact with the ground. The first chamber, 120, includes the support, for example.

[0068] The first chamber 120 includes, for example, a portion of wall in contact with the support, or with the ground.

[0069] The first axis Zi is defined by a direction along which the combustion chamber 100 extends, and by a direction going from the first chamber 120 to the second chamber 140.

[0070] Thus, the first axis Zi is oriented from the first chamber 120 to the second chamber 140.

[0071] Thus, the combustion chamber 100 has an elongated shape along the first axis Zi. According to one embodiment, the length of the combustion chamber 100 along the first axis Zi is between 20 meters and 30 meters.

[0072] This allows for a sufficient residence time of the combustion fumes in the combustion chamber 100, which optimizes their combustion.

[0073] First chamber 120, first volume Vi, and primary combustion fumes Fci

[0074] As can be seen in Figure 2, the first chamber 120 comprises a first chamber wall 120P delimiting and radially surrounding a first volume Vi.

[0075] Thus, the first wall of chamber 120P delimits the boundaries of the first volume Vi.

[0076] The first volume Vi corresponds to a portion of the total volume VT delimited by the walls of the combustion chamber 100.

[0077] This total volume VT also includes a second volume V2 and a third volume V3 delimited and surrounded radially by walls of the intermediate chamber 130, as well as a fourth volume V4 delimited and surrounded radially by a second wall of chamber 140P of the second chamber 140.

[0078] Thus, the first volume V1, the second volume V2, the third volume V3 and the fourth volume V4 form the total volume VT in which the combustion fumes are intended to circulate.

[0079] In other words, volumes V1 to V4 are "free" volumes of the combustion chamber 100, that is to say volumes intended to receive gases, such as combustion fumes.

[0080] These volumes communicate fluidly with each other.

[0081] This allows free circulation of gas, including "combustion fumes" in said volumes, from the inlet 121 of the first chamber 120 to the outlet 141 of the second chamber 140, which are defined below.

[0082] In this description, the combustion fumes entering the combustion chamber 100 through the inlet 121 are called "primary combustion fumes Fci", and the combustion fumes exiting the combustion chamber 100 through the outlet 141 are called "secondary combustion fumes Fœ". The fumes circulating in the total volume VT of the combustion chamber 100 are called "combustion fumes".

[0083] The first chamber 120 includes an inlet 121 through which it is intended to receive the primary combustion fumes Fci in the first volume V1.

[0084] Primary combustion fumes Fci are produced by the combustion of matter. They are generated, for example, in another combustion device whose outlet leads to the inlet 121 of the first chamber 120, for example a "primary combustion chamber" of a waste incineration line, for example a rotary kiln.

[0085] In this case, combustion chamber 100 is, for example, a "secondary combustion chamber" of the waste incineration line.

[0086] Primary combustion fumes (Fci) include, for example, gases from the combustion of "hazardous waste," that is, waste that poses a risk to human health or the environment.

[0087] They include, for example, but not limited to, at least one compound or at least one combination of compounds taken from the compounds listed below: at least one non-metallic oxide, such as carbon dioxide and / or nitrogen oxide, at least one metal, such as iron and / or zinc and / or vanadium and / or cadmium and / or barium and / or lead and / or nickel and / or chromium and / or cobalt and / or copper and / or manganese and / or tin and / or mercury, at least one alkali metal and / or at least one alkaline earth metal, at least one metalloid such as arsenic, at least one halogen such as chlorine and / or fluorine.

[0088] According to one embodiment, the entrance 121 includes an opening 121A made in the wall 120P of the first chamber 120.

[0089] This allows the entry of primary combustion fumes Fci into the first volume Vi.

[0090] According to one embodiment, as shown in Figure 1, the inlet 121 includes a portion of piping 121 B connected to the opening 121A provided in the wall 120P of the first chamber 120.

[0091] This allows the primary combustion fumes Fci to be guided into the first volume Vi.

[0092] According to one embodiment, the opening 121 A is generally circular in shape.

[0093] This facilitates the connection between the section of pipe 121 B and the wall 120P of the first chamber 120.

[0094] According to one embodiment, the combustion chamber 100 is configured to receive primary combustion fumes Fci whose temperature is between 700°C and 900°C.

[0095] According to one embodiment, the combustion chamber 100 is configured to receive primary combustion gases Fci with an inlet flow rate between 90000 Nm 3 / h and 120000 Nm 3 / h.

[0096] The notation "Nm 3 » corresponds to the unit of measurement “normo cubic meter”, or “normal cubic meter”, and corresponds to the content of a volume of one cubic meter, for a gas at a temperature of 0°C, 15°C or 20°C for a pressure of 1 normal atmosphere, conventionally noted “1 atm”, or 101,325 Pascal.

[0097] As shown in Figure 1, the intermediate chamber 130 is interposed between the first chamber 120 and the second chamber 140.

[0098] The intermediate chamber 130 includes a convergent chamber 131 comprising a first truncated cone 131 P delimiting and radially surrounding the second volume V2. Thus, the first truncated cone 131 P forms a wall of the convergent chamber 131, and therefore a portion of the wall of the combustion chamber 100.

[0099] The intermediate chamber 130 also includes a diverging chamber 132 comprising a second truncated cone 132P delimiting and radially surrounding the third volume V3.

[0100] Thus, the second truncated cone 132P forms a wall of the diverging chamber 132, and therefore another portion of the wall of the combustion chamber 100.

[0101] Each of the truncated cones can be of revolution or not.

[0102] The converging chamber 131 converges from the first chamber 120 to the diverging chamber 132 along the first axis Z1, and the diverging chamber 132 diverges to the second chamber 140 along the first axis Zi.

[0103] In other words, the first truncated cone 131 P converges towards the diverging chamber 132 along the first axis Z1 so that the second volume V2 delimited by the first truncated cone 131 P converges towards the diverging chamber 132 and the second truncated cone 132P diverges towards the second chamber 140 along the first axis Z1 so that the third volume V3 delimited by the second truncated cone 132P diverges towards the second chamber 140 along the first axis Z1.

[0104] In the embodiments shown in the figures, the converging chamber 131 converges from the first chamber 120 to the diverging chamber 132 along the first axis Z1, and the diverging chamber 132 diverges from the converging chamber 131 to the second chamber 140 along the first axis Z1.

[0105] In other words, the first truncated cone 131P converges from the first chamber wall 120P to the second truncated cone 132P along the first axis Z1, and the second truncated cone 132P diverges in the direction of convergence of the first truncated cone 131P to the second chamber wall 140P.

[0106] In other words, the cross-section of the intermediate chamber 130 decreases continuously along the first axis Z1 over the entire length of the converging chamber 131 until a minimum section, then increases continuously from the minimum section along the first axis Z1 over the entire length of the diverging chamber 132.

[0107] Thus, the cross-section of the passage of combustion fumes in the second volume V2 decreases continuously along the first axis Z1, then increases continuously in the third volume V3 along the first axis Z1.

[0108] The term “cross section” refers to a section belonging to a plane perpendicular to the first axis Z1.

[0109] Thus, the intermediate chamber 130 is of the "venturi device" or "venturi chamber" type.

[0110] The geometry of the converging chamber 131 allows an increase in the axial velocity of the combustion fumes which promotes turbulent flow, while the geometry of the diverging chamber 132 allows a reduction in axial velocity and an increase in the tangential velocity of the combustion fumes.

[0111] This promotes mixing of combustion fumes while increasing their residence time in the total volume VT, thus promoting complete combustion of the combustion fumes.

[0112] This also helps to reduce the amount of ash conveyed to outlet 141, and therefore to limit the fouling of another device receiving the secondary combustion fumes Fc2.

[0113] In this description, various angles are defined, including a first acute angle ai, a second acute angle 02, a third acute angle 03, and one or more fourth acute angles eu. These angles reflect variations in the geometry of the combustion chamber walls 100 around the first axis Z1, which notably impact the trajectories and velocity profiles of the combustion gases in the different volumes delimited by these walls, and therefore their residence time and combustion efficiency.

[0114] In this patent application, "angle substantially equal to a value" means a tolerance of + / -2% on the value of the angle.

[0115] For example, for an angle approximately equal to 90°, the value of the angle is between 88.2° and 91.8°.

[0116] As shown in Figure 3, a first generatrix G1 of the first truncated cone 131 P forms a first acute angle ai with a transverse plane PT orthogonal to the first axis Z1, and a second generatrix G2 of the second truncated cone 132P forms a second acute angle 02 greater than the first acute angle ai with the transverse plane PT.

[0117] In other words, the cross-section of the converging chamber 131 decreases more rapidly from the first chamber 120 to the diverging chamber 131 than the cross-section of the diverging chamber 132 increases towards the second chamber 140.

[0118] This promotes the formation of a turbulent flow which improves the mixing of fumes and the homogeneity of the temperature distribution, while promoting a longer residence time of combustion fumes, which has the effect of improving combustion.

[0119] This also allows optimal occupation of the total volume VT by the combustion fumes, which improves the homogeneity of the temperature distribution and therefore the efficiency of combustion.

[0120] According to one embodiment, the combustion chamber 100 is configured to allow a residence time of less than or equal to two seconds of combustion fumes in the total volume VT.

[0121] This allows for efficient combustion of the combustion fumes. According to one embodiment, the measurement of the first acute angle ai is between 35° and 40°.

[0122] According to one embodiment, the measurement of the second acute angle 02 is between 50° and 60°.

[0123] According to one embodiment, the measurement of the second acute angle 02 is approximately equal to 55°. This helps to facilitate the flow of combustion fumes towards outlet 141.

[0124] According to one embodiment, a difference between a measurement of the first acute angle ai and a measurement of the second acute angle 02 is less than or equal to 20°.

[0125] According to one embodiment, a difference between a measure of the first acute angle ai and a measure of the second acute angle 02 is less than or equal to 15°.

[0126] According to one embodiment, a difference between a measure of the first acute angle ai and a measure of the second acute angle 02 is less than or equal to 10°.

[0127] According to one embodiment, the difference between a measurement of the first acute angle ai and a measurement of the second acute angle 02 is between 15° and 20°.

[0128] According to one embodiment, the difference between a measurement of the first acute angle ai and a measurement of the second acute angle 02 is between 10° and 15°.

[0129] This helps to limit sudden variations in the geometry of the walls of the intermediate chamber 130, which promotes the flow of combustion fumes towards the outlet 141.

[0130] According to one embodiment, the slope of the surface delimiting the second volume V2 and / or of the surface delimiting the third volume V3 varies continuously around the first axis Z1.

[0131] In other words, in this case, the first truncated cone 131 and / or the second truncated cone 132 comprise a plurality of generatrices forming different respective angles with the transverse plane PT.

[0132] According to one embodiment, as shown in figures 1 to 5, the converging chamber 131 and the diverging chamber 132 are joined together.

[0133] In other words, in this configuration, the first truncated cone 131 P and the second truncated cone 132P are contiguous along the first axis Zi.

[0134] This helps to improve the mechanical strength and stability of the combustion chamber 100.

[0135] This also helps to maintain a homogeneous flow in the combustion chamber 100.

[0136] According to another embodiment, the converging chamber 131 and the diverging chamber 132 are spaced along the first axis Z1.

[0137] In other words, in this configuration, the first truncated cone 131 P and the second truncated cone 132P are not contiguous along the first axis Z1.

[0138] For example, they are separated from each other by a cylindrical wall of the intermediate chamber 130 with a generator parallel to the first axis Z1, so that the cylindrical wall delimits a cylindrical free volume of the intermediate chamber 130. This allows a more gradual accompaniment of the combustion fumes from the second volume V2 to the third volume V3, which helps to limit the effects of detachment and to promote the accompaniment of these combustion fumes towards the outlet 141 of the second chamber 140.

[0139] As mentioned previously, the second chamber 140 includes a second chamber wall 140P, and also includes an outlet 141 through which it is intended to evacuate secondary combustion fumes Fc2 resulting from combustion of the combustion fumes in the total volume VT.

[0140] According to one embodiment, the exit 141 includes an opening 141 A provided in the second chamber wall 140P of the second chamber 140.

[0141] This allows secondary combustion fumes Fœ to be evacuated outside of the combustion chamber 100.

[0142] According to one embodiment, the outlet 141 includes a portion of piping 141 B opening on the one hand into the fourth volume V4 via the opening 141 A, and on the other hand into an area outside the combustion chamber 100.

[0143] The outlet 141 includes, for example, a portion of a 141 B pipe opening onto a volume delimited by walls of a heat recovery device, such as a heat recovery boiler from a waste incineration line.

[0144] This allows for energy recovery from the secondary combustion fumes Fœ exiting the combustion chamber 100.

[0145] According to one embodiment, as shown in Figure 4, a first portion 132PA of the second truncated cone 132P is located on a first side C1 of a first longitudinal plane PLI comprising the first axis Z1 and being orthogonal to the transverse plane PT, and a second portion 132PB of the second truncated cone 132P and the outlet 141 are located on a second side C2 of said longitudinal plane PL, the first portion 132PA comprising the second generatrix G2 forming the second acute angle 02 with the transverse plane PT, and the second portion 132PB comprising a third generatrix G3 forming a third acute angle 03 lower than the second acute angle 02 with the transverse plane PT.

[0146] Thus, in this embodiment, the diverging chamber 132 is asymmetric with respect to the first longitudinal plane PLI.

[0147] This allows the combustion fumes to be guided towards the outlet 141. It also allows the areas of combustion fume recirculation to be limited in the third volume V3 along the inner wall of the second truncated cone 132P, and thus limits an accumulation of ash on said wall.

[0148] According to one embodiment, the second truncated cone 132P comprises a plurality of generatrices G3 forming respective third acute angles 03 with the transverse plane PT whose measures gradually decrease around the first axis Z1 in the direction of the outlet 141 of the second chamber 140. In other words, according to this embodiment, the slope of the wall of the diverging chamber 132 gradually decreases around the first axis Zi until a minimum slope in the direction of the outlet 141, then gradually increases around the first axis Zi until a maximum slope.

[0149] This allows for a gradual flow of combustion fumes towards outlet 141 of the second chamber 141.

[0150] This also helps to limit the formation of recirculation zones in the third volume V3 along the inner wall of the second truncated cone 132P, and therefore to limit the fouling of the diverging chamber 132.

[0151] According to one embodiment, a difference between the measurement of the third acute angle 03 and a measurement of the second acute angle 02 is less than or equal to 10°.

[0152] This allows for a gradual flow of combustion fumes towards outlet 141 while promoting the mechanical strength and stability of combustion chamber 100.

[0153] According to one embodiment, a first portion 140PA of the second chamber wall 140P is located on the first side C1 of the first longitudinal plane PLI and a second portion 140PB of the second chamber wall 140P is located on the second side C2 of the first longitudinal plane Pu and connects the second truncated cone 132P to the outlet 141, said second portion 140PB of the second chamber wall 140P forming, in a second longitudinal plane PL2 comprising the first axis Z1 and being orthogonal to the first longitudinal plane PLI, a fourth acute angle eu less than the third acute angle 03 with the transverse plane PT.

[0154] In other words, according to this embodiment, the slope of the second chamber wall 140P is less than the slope of the second truncated cone 132P along the first axis Z1.

[0155] This helps to facilitate the flow of combustion fumes towards exit 141.

[0156] According to one embodiment, a measurement of the fourth acute angle 04 is between 45° and 55°.

[0157] According to one embodiment, a difference between a measurement of the fourth acute angle 04 and a measurement of the second acute angle 02 and / or a measurement of the third acute angle 03 is less than or equal to 5°.

[0158] According to one embodiment, a difference between a measurement of the fourth acute angle 04 and a measurement of the second acute angle 02 and / or a measurement of the third acute angle 03 is less than or equal to 10°.

[0159] According to one embodiment, a difference between a measurement of the fourth acute angle 04 and a measurement of the second acute angle 02 and / or a measurement of the third acute angle 03 is less than or equal to 15°.

[0160] This helps to limit a variation in geometry between the wall of the diverging chamber, i.e. the second truncated cone 132P, and the second wall of chamber 140P, which helps to promote the flow of combustion fumes towards the outlet 141 of the second chamber 140. This also helps to limit the phenomenon of "detachment" of the combustion fumes, i.e. to limit a phenomenon whereby these fumes would continue their trajectory in a direction imposed by the geometry of the second truncated cone 132P due to an excessively high variation in angle between the third acute angle co and the fourth acute angle eu.

[0161] This also helps to avoid the appearance of recirculation zones, or "dead" zones, caused by the recirculation of gases in the combustion chamber 100 resulting from such a stall.

[0162] The appearance of such recirculation zones would have the disadvantages, on the one hand, of reducing the volume allowing the passage of combustion fumes, and therefore of causing an acceleration of the flow reducing the residence time and decreasing the efficiency of combustion, and on the other hand, of causing an accumulation of ash deposits on the walls of the combustion chamber 100.

[0163] According to one embodiment, the second portion 140PB of the second chamber wall 140P forms, in the second longitudinal plane PL2 and with the transverse plane PT, a plurality of successive fourth acute angles cua, O4b, O4c whose measures are decreasing in the direction of the exit 141.

[0164] These "successive" angles define a progressive variation of the slope of the second portion 140PB of the second chamber wall 140P of the second chamber 140 connecting the diverging chamber 132 to the outlet 141.

[0165] This also helps to prevent the combustion fumes from detaching from the second chamber wall 140P, which promotes a gradual flow of these fumes towards the outlet 141.

[0166] This also helps to limit fouling of the combustion chamber 100, by allowing the ash and dust contained in the combustion fumes to fall by gravity into the first volume Vi towards a device for recovering unburned material, for example a water conveyor.

[0167] Figure 5 illustrates an embodiment in which the second portion 140PB of the second chamber wall 140P forms three successive acute fourth angles cua, cub, eue with the transverse plane PT.

[0168] According to other embodiments, the second portion 140PB of the second chamber wall 140P is capable of forming a lower number of successive acute fourth angles with the transverse plane PT, for example two angles, or a higher number of successive acute fourth angles, for example four angles or five angles.

[0169] In other words, according to this embodiment, the slope of the second portion 140PB of the second chamber wall 140P gradually decreases towards the exit 141.

[0170] According to one embodiment, a difference in measurement between two successive fourth acute angles c(4a, cub) is less than 5°.

[0171] According to one embodiment, a difference in measurement between two successive fourth acute angles cua, cub is less than 10°.

[0172] According to one embodiment, a difference in measure between two successive fourth acute angles cua, cub is less than 15°. The notations cua, cub do not limit these embodiments to these particular angles.

[0173] These embodiments are applicable to any other pair of successive fourth angles, for example the cub and eue angles, or other angles not shown in the figures.

[0174] According to an embodiment shown in the figures, the inlet 121 of the first chamber 120 includes at least a portion of piping 121 B opening onto the first volume Vi via an opening 121A provided in the wall 120P of the first chamber.

[0175] The inlet 121 includes, for example, the portion of pipe 121 B opening on one side into the first volume Vi, and opening on the other side into a volume delimited by walls of another combustion device from which the primary combustion fumes Fci originate.

[0176] This allows the primary combustion fumes Fci to be guided along an inlet axis Xi into the first volume Vi.

[0177] The inlet axis Xi is the axis of the pipe opening into the first volume Vi via the opening 121 A; that is, the axis along which the pipe extends longitudinally. This axis is also referred to as the "longitudinal axis Xi of the pipe" in this description.

[0178] As an example, the section of pipe 121 B is substantially cylindrical. In this case, the axis of the pipe is the axis of the cylinder.

[0179] In other words, according to this embodiment, the portion of piping 121 B defines an inlet axis Xi of the primary combustion fumes Fci into the first volume Vi.

[0180] According to one embodiment, the input axis Xi forms an angle approximately equal to 90° with the first axis Zi.

[0181] According to one embodiment, as shown in Figure 6, the input axis Xi forms a fifth angle as approximately between 93° and 95° with the first axis Zi.

[0182] One benefit is to ensure good mechanical strength between the portion of pipe 121 B of the inlet 121 and the first chamber wall 120P.

[0183] The angle formed by the input axis Xi with the first axis Zi is, for example, formed in a longitudinal plane including the first axis Zi.

[0184] According to one embodiment, the input axis Xi has a positive component along the first axis Zi, in the direction from the first chamber 120 to the second chamber 140.

[0185] One benefit is to guide the primary combustion fumes Fci during their injection into the first volume Vi along a slightly upward trajectory along the first axis Zi, which helps to promote faster combustion and to guide the combustion fumes towards the According to one embodiment, the combustion chamber 100 includes at least one burner 122 configured to emit a flame towards the total volume VT.

[0186] The 122 burner, for example, is configured to achieve combustion of a mixture of a fuel, such as a liquid or a gas, for example fuel oil, and an oxidizer, for example air, in order to produce said flame.

[0187] This allows a high temperature to be maintained in the total volume VT, for example a temperature above 850°C, which helps to promote complete combustion of the combustion fumes.

[0188] This also helps to promote the creation of a turbulent flow, which promotes better mixing of combustion fumes, thus improving combustion efficiency.

[0189] According to one embodiment, the burner 122 is configured to inject an oxidant, for example air, into the first volume Vi.

[0190] This helps to improve the efficiency of combustion of combustion fumes.

[0191] According to one embodiment, the burner 122 is configured to emit a flame along an emission axis ZB oriented towards the first volume Vi.

[0192] For this purpose, the burner 122 is for example arranged on the first wall of chamber 120P, and the burner head emitting said flame is for example oriented towards the first volume Vi.

[0193] This helps to promote the creation of a turbulent flow in the first volume Vi and to improve combustion efficiency.

[0194] According to one embodiment, the combustion chamber 100 comprises a plurality of burners 122, each configured to emit a respective flame along respective emission axes ZB of said burners 122 being oriented towards the internal volume VT of the combustion chamber 100.

[0195] This improves the combustion of the combustion gases. According to one embodiment, as shown in Figure 7, the combustion chamber 100 comprises a plurality of burners 122, each configured to emit a respective flame along respective emission axes ZB of said burners 122 oriented towards the first volume Vi.

[0196] In this embodiment, the burners 122 are for example distributed on the first wall of chamber 120P around the first axis Zi.

[0197] This helps to promote the creation of a turbulent flow in the first volume Vi, and therefore to improve combustion efficiency.

[0198] According to one embodiment, at least one burner 122 is arranged on the first wall of chamber 120P at a height above the inlet 121 of the first chamber 120 along the first axis Zi in the direction of the figures, i.e. in the direction from the first chamber 120 to the second chamber 140.

[0199] According to one embodiment, the combustion chamber 100 comprises a plurality of burners 122 distributed on the first chamber wall 120P around the first axis Zi has a dimension higher than the inlet 121 along the first axis Zi.

[0200] This allows increasing the proportion of available volume that can be occupied by combustion fumes in the first volume Vi. According to one embodiment, the burners 122 are distributed around the first axis Zi at the same height along the first axis Zi.

[0201] According to one embodiment, the combustion chamber 100 comprises a plurality of burners 122 whose respective emission axes ZB are oriented towards the first volume Vi, orthogonal projections on the transverse plane PT of the respective emission axes ZB of at least two burners 122 forming an angle of substantially 90° between them.

[0202] This improves the combustion of the combustion gases. According to one embodiment, an orthogonal projection of the emission axis ZB of at least one burner 122 onto the transverse plane PT forms an angle of approximately 120° with an orthogonal projection of the inlet axis Xi of the primary combustion gases Fci onto said first transverse plane PTI.

[0203] This improves the combustion of the flue gases. According to one embodiment, as shown in Figure 5, the combustion chamber 100 includes at least one injection lance 123.

[0204] According to one embodiment, the injection lance 123 is configured to inject an auxiliary flow along an injection axis ZL of the lance oriented towards the total volume VT.

[0205] The auxiliary flow includes, for example, a liquid or a gas. This provides an additional supply of combustible material to the total volume VT, thereby improving combustion efficiency.

[0206] According to one embodiment, the combustion chamber 100 comprises a plurality of injection lances 123 arranged on the first chamber wall 120P and distributed around the first axis Zi, the respective injection axes ZL of said injection lances 123 being oriented towards the first volume Vi.

[0207] This helps to improve the combustion of combustion fumes in the first volume Vi.

[0208] This also allows for a greater supply of fuel in the first volume Vi, which helps to improve combustion efficiency.

[0209] According to one embodiment, at least one injection lance 123 is arranged at a height above the inlet 121 of the first chamber 120 along the first axis Zi.

[0210] This helps to promote the formation of a turbulent flow in the first volume Vi and to improve combustion efficiency.

[0211] According to one embodiment, an orthogonal projection of the injection axis ZL of at least one injection lance 123 onto the transverse plane PT forms a non-zero angle with an orthogonal projection of the inlet axis Xi of the primary combustion fumes Fci onto said first transverse plane PTI.

[0212] The non-zero angle is, for example, approximately equal to 45°. "Approximately equal to 45°" means a tolerance of plus or minus 10°. This allows for improved combustion efficiency.

[0213] According to one embodiment, orthogonal projections of the respective injection axes ZL of a plurality of injection lances 123 onto the transverse plane PT each form a respective non-zero angle with an orthogonal projection of the inlet axis Xi of the primary combustion fumes Fci onto said first transverse plane PTI.

[0214] According to this embodiment, the angles formed are, for example, each approximately equal to 45°.

[0215] In other words, in this configuration, the respective injection axes ZL of the respective injection lances 123 are neither parallel to, nor coincide with, the inlet axis Xi of the primary combustion fumes Fci in the first volume Vi.

[0216] This helps to promote the formation of a homogeneous flow in the first volume Vi while optimizing the proportion of the first volume Vi that can be occupied by combustion fumes, which improves combustion efficiency.

[0217] According to one embodiment, orthogonal projections of the respective injection axes ZL of a plurality of injection lances 123 onto the transverse plane PT form angles between them that are not harmed in said transverse plane PT.

[0218] The respective angles formed are, for example, approximately equal to 90°.

[0219] This also helps to promote the formation of a homogeneous flow in the first volume Vi, which improves the efficiency of combustion of the combustion fumes.

[0220] This also maximizes the proportion of the first volume Vi that can be occupied by combustion fumes, which also helps to improve combustion.

[0221] According to one embodiment, the injection axis ZL of at least one injection lance 123 is substantially parallel to the emission axis ZB of at least one burner 122.

[0222] According to one embodiment, at least one injection lance 123 is arranged on the first chamber wall 121 P "above" or "below" a burner 122, i.e. at a different height along the first axis Zi, in the direction from the first chamber 120 to the second chamber 140.

[0223] This helps to improve combustion efficiency in the first volume Vi.

[0224] According to one embodiment, the injection axis ZL of at least one injection lance 123 and / or the emission axis ZB of at least one burner 122 forms an angle that is not parallel to the transverse plane PT.

[0225] According to one embodiment, at least one burner 122 and / or at least one injection lance 123 is configured to emit respectively a flame or an auxiliary flow along an upward trajectory along the first axis Zi in the first volume Vi. This makes it possible to promote the accompaniment of the combustion fumes towards the second volume V2 while improving the combustion efficiency.

[0226] According to another aspect, the invention relates to a combustion device 1000 comprising the combustion chamber 100.

[0227] The combustion device 1000 includes for example a primary combustion chamber in which the primary combustion fumes Fci are generated entering the first volume V1 of the combustion chamber 100, for example a rotary oven.

[0228] The combustion device 1000 includes, for example, another device to which the secondary combustion fumes FC2 evacuated from the combustion chamber 100 are routed, for example a heat recovery device.

[0229] The combustion device 1000 includes, for example, a plurality of devices from a waste treatment line, for example, hazardous waste.

[0230] The combustion system includes, for example, the waste incineration line.

Claims

DEMANDS 1. Combustion chamber (100) comprising a volume intended to receive combustion fumes, the volume comprising a first, a second, a third and a fourth volume (Vi, V2, V3, V4) communicating fluidly with each other, and comprising: • a first chamber (120) comprising a first chamber wall (120P) delimiting the first volume (V1), and comprising an inlet (121) to receive primary combustion fumes (Fci) into the first volume (V1); • an intermediate chamber (130) comprising a converging chamber (131) comprising a first truncated cone (131 P) delimiting the second volume (V2), and comprising a diverging chamber (132) comprising a second truncated cone (132P) delimiting the third volume (V3); • a second chamber (140) comprising a second chamber wall (140P) delimiting the fourth volume (V4), and comprising an outlet (141) for evacuating secondary combustion fumes (Fc?) generated by combustion of primary combustion fumes (Fci) in the combustion chamber (100); the intermediate chamber (130) being interposed between the first chamber (120) and the second chamber (140) along a first axis (Z1), the converging chamber (131) converging along the first axis (Z1) in a direction from the first chamber (120) to the diverging chamber (132) and said diverging chamber (132) diverging along the first axis (Z1) in said direction, the intermediate chamber (130) being configured such that: • that a first generatrix (G1) of the first truncated cone (131 P) forms a first acute angle (ai) with a transverse plane (PT) orthogonal to the first axis (Z1) and, • that a second generatrix (G2) of the second truncated cone (132P) forms a second acute angle (02) greater than the first acute angle (ai) with said transverse plane (PT).

2. Combustion chamber (100) according to claim 1, in which a first portion (132PA) of the second truncated cone (132P) is located on a first side (C1) of a first longitudinal plane (Pu) comprising the first axis (Z1), and in which a second portion (132PB) of the second truncated cone (132P) and the outlet (141) of the second chamber (140) are located on a second side (C2) of the first longitudinal plane (PLI) separating the first side (C1) from the second side (C2), and in which the first portion (132PA) of the second truncated cone (132P) comprises the second generatrix (G2) and the second portion (132PB) of the second truncated cone (132P) comprises a third generatrix (G3) forming a third acute angle (as) lower than the second acute angle (02) with the transverse plane (PT).

3. Combustion chamber (100) according to claim 2, wherein a first portion (140PA) of the second chamber wall (140P) is located on the first side (C1) of the first longitudinal plane (PLI), and wherein a second portion (140PB) of the second chamber wall (140P) is located on the second side (C2) of the first longitudinal plane (PLI) and connects the second truncated cone (132P) to the outlet (141) of the second chamber (140), and wherein the second portion (140PB) of the second chamber wall (140P) forms, in a second longitudinal plane (P1.2) comprising the first axis (Z1) and being orthogonal to the first longitudinal plane (Pu), a fourth acute angle (04) less than the third acute angle (as) with the transverse plane (PT).

4. Combustion chamber (100) according to claim 3, in which the second portion (140PB) of the second chamber wall (140P) forms, from the diverging chamber (132) to the outlet (141), in the second longitudinal plane (P1.2) and with the transverse plane (PT), a plurality of successive fourth acute angles (a4a, 04b, 04c) less than the third acute angle (as), and whose respective measures gradually decrease towards the outlet (141) of the second chamber (140).

5. Combustion chamber (100) according to any one of the preceding claims, wherein the first acute angle (ai) is between 35° and 40°.

6. Combustion chamber (100) according to any one of the preceding claims, wherein the second acute angle (02) is between 50° and 60°.

7. Combustion chamber (100) according to any one of the preceding claims, wherein the difference between the first acute angle (ai) and the second acute angle (02) is between 15° and 20°.

8. Combustion chamber (100) according to any one of the preceding claims, in which the second truncated cone (132P) is attached to the first truncated cone (131P).

9. Combustion chamber (100) according to any one of the preceding claims, wherein the length of the second truncated cone (132P) along the first axis (Z1) is greater than the length of the first truncated cone (131P) along the first axis (Z1). 10.Combustion chamber (100) according to any one of the preceding claims, wherein the inlet (121) of the first chamber (120) comprises an opening (121 A) formed on the first chamber wall (120P) and opening onto the first volume (Vi), and further comprises a portion (121 B) of a pipe extended along a longitudinal axis (Xi) of the pipe so as to open onto said opening (121 A), said longitudinal axis (Xi) being oriented along the pipe towards the opening (121 A) and forming a fifth angle (as) between 93° and 95° with the first axis (Zi) such that said longitudinal axis (Xi) has a positive component along the first axis (Zi) in the direction from the first chamber (120) to the second chamber (140).

11. Combustion chamber (100) according to any one of the preceding claims, comprising at least one burner (122) configured to emit a flame along an emission axis (ZB) oriented towards the first volume (Vi), and in which an orthogonal projection of the emission axis (ZB) of said burner (122) onto the transverse plane (PT) forms a non-zero angle with an orthogonal projection onto said transverse plane (PT) of an inlet axis (Xi) of the primary combustion fumes (Fci) into the first volume (Vi).

12. Combustion chamber (100) according to claim 11, in which the non-zero angle is substantially equal to 120°.

13. Combustion chamber (100) according to any one of claims 11 to 12, comprising at least one injection lance (123) configured to emit an auxiliary flow comprising at least one fuel along an injection axis (ZL) oriented towards the first volume (Vi), and in which an orthogonal projection of said injection axis (ZL) onto the transverse plane (PT) forms a non-zero angle with an orthogonal projection onto said transverse plane (PT) of the inlet axis (Xi).

14. Combustion chamber according to claim 13, comprising a plurality of injection lances (123) being distributed around the first axis (Zi) and each being capable of emitting an auxiliary flow comprising at least one fuel along distinct respective injection axes (ZL) each oriented towards the first volume (Vi).

15. Combustion chamber according to claim 14, in which orthogonal projections of the respective injection axes (ZL) of at least two injection lances (123) onto the transverse plane (PT) form an angle substantially equal to 90° between them.

16. Combustion device according to any one of the preceding claims, comprising the combustion chamber (100) according to any one of the preceding claims, and further comprising a primary combustion chamber delivering the primary combustion fumes (Fci).

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