Method for producing mineral fibers using low carbon dioxide emission centrifugal separation

Abstract

A solution is proposed to reduce the amount of carbon dioxide produced compared to known mineral fiber production facilities producing a comparable amount of mineral fiber. The present invention relates to a method for producing mineral fibers using an installation comprising an annular burner, the burner comprising a combustion chamber and a nozzle connecting the combustion chamber to the outside of the burner, and a fiber spinner suitable for forming filaments by centrifugal spinning, the method comprising at least one step of injecting a first fluid into the combustion chamber at a first flow rate, the first fluid comprising a fuel, the fuel comprising dihydrogen, the volume fraction of dihydrogen in the first fluid being greater than 0.05, wherein the pressure in the combustion chamber is between 1961 Pa and 7845 Pa.

Description

[Technical Field]

[0001] The present invention relates to a method for producing mineral fibers by internal centrifugal spinning and to an installation suitable for carrying out this method, which is particularly applicable to the industrial production of mineral wool. [Background technology]

[0002] The production of mineral wool using an internal centrifugal process is known. With reference to FIG. 1, French Patent No. 305767 describes a known installation 2 for producing mineral fibers 1 by internal centrifugal spinning, comprising a fiber spinner 6, a basket 16, and a shaft 17 arranged along a main axis X. The shaft 17 is rotatable by a motor (not shown). The shaft 17 is hollow, forming a duct 18 through which molten thermoplastic material can flow. The thermoplastic material is preferably glass. The installation 2 is configured such that the main axis X is vertical in the Earth's reference frame, allowing the thermoplastic material to be poured into the duct 18 and fall into the basket 16. The duct 18 is fluidly connected at one end to a supply of molten thermoplastic material. The spinner 6 and the basket 16 are attached to the other end of the shaft by a tulip 19.

[0003] The spinner 6 includes a first annular wall 20 and a web 21. The first annular wall 20 has a plurality of holes 7 formed therein. The web 21 is disposed between the first annular wall 20 and the tulip 19. The web 21 forms the top of the spinner 6. The diameter D of the spinner A is the radius R of spinner 6 A The radius R is defined as twice the A is defined by the distance between the major axis X and the point A on the first wall 20 that is furthest from the major axis X.

[0004] The basket 16 has a second annular wall 22. The second annular wall 22 has a plurality of holes. The diameter D of the basket 16 is pis the radius R of the basket 16 p The radius R is defined as twice the p is defined by the distance between the major axis X and the point B on the second wall 22 that is furthest from the major axis X. The basket is mounted inside the fiber spinner.

[0005] During production of mineral fibers 1 by facility 2, shaft 17, fiber spinner 6, and basket 16 rotate together about major axis X. Molten thermoplastic material is forced from a thermoplastic material source into duct 18 of shaft 17, through duct 18, and into basket 16. The material is projected onto second annular wall 22 by centrifugal force driven by the assembly of shaft 17, fiber spinner 6, and basket 16. The material then flows through a plurality of orifices in second annular wall 22 before being projected onto first annular wall 20. The material then flows into a plurality of holes 7 in first annular wall 20, forming filaments 8 of material.

[0006] As the material is projected onto the first annular wall 20, a reservoir of material is formed within the fiber spinner 6. This reservoir provides a continuous supply to a plurality of holes 7 within the first wall 20, thereby forming filaments 8.

[0007] The installation 2 comprises an annular burner 3 configured to generate a drawing gas flow for drawing the filaments 8 produced at the outlets of the orifices 8 in the first wall 20. The burner 3 has an axis of symmetry coinciding with the main axis X of the shaft 17. The burner 3 has a gas outlet arranged above the first annular wall 20. The drawing gas flow leaving the burner 3 is tangential to the first wall 20. The drawing gas flow heats both the first wall 20 and the filaments 8 formed at the outlets of the holes 8 in the first wall 20. Under the action of the drawing gas flow, the filaments 8 elongate and then break, forming mineral fibers 1. The mineral fibers 1 are then collected below the spinner 6.

[0008] Referring to WO 03 / 069226, the drawing gas stream is generated by combustion in an annular burner 3. The annular burner 3 may include a combustion chamber 4 and a nozzle 5. The nozzle 5 connects the combustion chamber to the outside of the burner 3. An oxidizer and a fuel are supplied to the combustion chamber 4. A combustion reaction is initiated in the combustion chamber. Methane is typically used as the fuel. Air is typically used as the oxidizer. The above-mentioned combustion reaction maintains the drawing gas stream at a sufficient drawing temperature at the lip 11 of the nozzle 5, for example, between 1100°C and 1600°C, and a gas flow rate sufficient to elongate the filament 8, for example, 5000 m 3 / hour~8000m 3 This makes it possible to maintain a gas flow rate of 1000 / hour.

[0009] However, the combustion reactions described above produce significant amounts of carbon dioxide and may also produce nitrogen oxides, sulfur oxides, carbon monoxide, and hydrocarbons that are not consumed in the reaction, but for health and / or environmental reasons it is desirable to reduce the production of these substances. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] French Patent No. 305767 [Patent Document 2] International Publication No. 03 / 069226 Summary of the Invention [Problem to be solved by the invention]

[0011] One of the aims of the present invention is to propose a solution for reducing the amount of carbon dioxide produced compared to known mineral fibre production facilities producing a comparable amount of mineral fibre. [Means for solving the problem]

[0012] The object, within the scope of the present invention, is a method for producing mineral fibers by means of an installation, which comprises: - an annular burner comprising a combustion chamber and a nozzle connecting the combustion chamber to the outside of the burner; a fiber spinner provided with an orifice, the fiber spinner being suitable for receiving a molten thermoplastic material, in particular a mineral material, preferably glass, and for forming filaments of the thermoplastic material from the orifice by centrifugal spinning of the spinner; It is equipped with The method comprises at least the following: - a first step of producing a filament; - a second step of injecting a first fluid into the combustion chamber at a first flow rate, the first fluid comprising a fuel, the fuel comprising dihydrogen, and a volume fraction of the dihydrogen in the first fluid being greater than 0.05; a third step of injecting a second fluid into the combustion chamber at a second flow rate, the second fluid having an oxygen volume fraction greater than 0.10; a fourth step of combusting the fuel and oxygen introduced into the combustion chamber in the second and third steps; a fifth step of drawing the filaments, the nozzle being arranged so that the compounds contained in the combustion chamber after the combustion in the fourth step are discharged from the burner through the nozzle, and then the filaments produced in the first step are drawn to form mineral fibers; This is achieved by a method comprising:

[0013] The invention is advantageously completed by the following characteristics, taken alone or in any technically possible combination: - in the fourth step, the pressure P in the combustion chamber Bis 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq), particularly 4413 Pa (450 mmAq) to 7355 Pa (750 mmAq), and preferably 5394 Pa (550 mmAq) to 6374 Pa (650 mmAq); - The spinner has a diameter D A and the nozzle has a diameter D T The average momentum of the compound passing through the nozzle cross section in the fifth step is 2π D T ·1961·(D A +D T )~2π·D T 7354 (D A +D T ), especially 2π D T 4413 (D A +D T )~2π·D T 7355 (D A +D T ), preferably 2π D T 5393 (D A +D T )~2π·D T 6374 (D A +D T ) the equivalence ratio φ of the aggregate formed by the mixture of the first and second fluids in the combustion chamber is between 0.40 and 0.90, in particular between 0.50 and 0.80, preferably between 0.60 and 0.70; - the fuel comprises an organic compound, preferably methane; a lip defines the boundary between the nozzle and the outside of the burner, the temperature measured at the lip in the fourth step being between 1100°C and 1600°C, in particular between 1200°C and 1550°C, preferably between 1300°C and 1550°C; - the flame speed S of the fourth combustion step depending on the composition of the first fluid and the composition of the second fluid; f is defined, the first fluid and the second fluid are mixed preferably in a burner before being introduced into the combustion chamber to form a mixture, and the mixture is injected into the combustion chamber in the second step and the third step, and the average velocity U of the mixture when injected into the combustion chamber is greater than the flame speed S fThat is all, - mixing the first fluid and the second fluid, preferably in a burner, to form a mixture before introducing them into the combustion chamber, the mixture having a pressure of more than 102,000 Pa, preferably more than 103,000 Pa; - mixing the first fluid and the second fluid in the burner before introducing them into the combustion chamber; - the burner comprises an injector, the injector comprising a first fluid inlet, a second fluid inlet, a mixing duct fluidly connected to the first fluid inlet and the second fluid inlet, and an outlet fluidly connecting the mixing duct to the combustion chamber, the geometry of the injector being configured such that when the first fluid and the second fluid are injected into the injector, the first fluid and the second fluid flow along at least a portion of the mixing duct in the same primary flow direction, such that the second fluid exhibits rotation relative to the first fluid about an axis oriented in the primary flow direction; - the injector comprises an angular deflection element adapted to generate a swirling flow of the first and / or second fluid in the mixing duct; - the volume fraction of dihydrogen in the first fluid is 0.15 to 0.20, and the first and second fluids are mixed and then injected into the burner; - the burner is configured to separately supply the first fluid and the second fluid to the injector; - The nozzle geometry, burner geometry, first flow rate, second flow rate, first fluid composition, and second fluid composition affect the pressure P in the combustion chamber. B is set to be 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq), particularly 4413 Pa (450 mmAq) to 7355 Pa (750 mmAq), and preferably 5394 Pa (550 mmAq) to 6374 Pa (650 mmAq); - The spinner has a diameter D A and the nozzle has a diameter D T and the nozzle geometry, the burner geometry, the first flow rate, the second flow rate, the composition of the first fluid, and the composition of the second fluid are such that the average momentum of the compound passing through the nozzle cross section in the fifth step is 2π D.T ·1961·(D A +D T )~2π·D T 7354 (D A +D T ), especially 2π D T 4413 (D A +D T )~2π·D T 7355 (D A +D T ), preferably 2π D T 5393 (D A +D T )~2π·D T 6374 (D A +D T ) be determined to be the first flow rate, the second flow rate, the composition of the first fluid and the composition of the second fluid are selected such that the equivalence ratio φ of the aggregate formed by the mixture of the first fluid and the second fluid in the combustion chamber is between 0.40 and 0.90, in particular between 0.50 and 0.80, preferably between 0.60 and 0.70; the first fluid has a dihydrogen volume fraction greater than 0.2, in particular greater than 0.5;

[0014] Another aspect of the present invention is an installation for producing mineral fibers, said installation comprising: - an annular burner comprising a combustion chamber and a nozzle connecting the combustion chamber to the outside of the burner; a fiber spinner provided with an orifice, the fiber spinner being suitable for receiving a molten thermoplastic material, in particular a mineral material, and for forming filaments of the thermoplastic material from the orifice by centrifugal spinning of the spinner; It is equipped with Burner is as follows: a first inlet configured to receive a first fluid, the first fluid comprising a fuel, the fuel comprising dihydrogen, wherein a volume fraction of the dihydrogen in the first fluid is greater than 0.05, the first inlet being fluidly connected to the combustion chamber; a second inlet configured to receive a second fluid, the second fluid having an oxygen volume fraction greater than 0.10, the second inlet fluidly connected to the combustion chamber; and It is a facility that is equipped with the following.

[0015] Advantageously, the first inlet is configured to receive a first fluid at a first flow rate and the second inlet is configured to receive a second fluid at a second flow rate, and the arrangement comprises a control unit, the control unit being adapted to regulate the flow rates of the first fluid and the second fluid in relation to a pressure P in the combustion chamber. B The pressure is controlled to be 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq), particularly 4413 Pa (450 mmAq) to 7355 Pa (750 mmAq), and preferably 5394 Pa (550 mmAq) to 6374 Pa (650 mmAq).

[0016] Advantageously, the arrangement comprises an injector, the injector comprising a first fluid inlet, a second fluid inlet, a mixing duct fluidly connected to the first fluid inlet and the second fluid inlet, and an outlet fluidly connecting the mixing duct to the combustion chamber; the first burner inlet is fluidly connected to the first injector fluid inlet; the second burner inlet is fluidly connected to the second injector fluid inlet; The injector is configured such that when the first fluid and the second fluid are injected into the injector, the first fluid and the second fluid flow along at least a portion of the mixing duct in the same primary flow direction, causing the second fluid to exhibit rotation relative to the first fluid about an axis oriented in the primary flow direction. [Brief explanation of the drawings]

[0017] Other characteristics, objects and advantages of the present invention will become apparent from the following description, which is given by way of example only and is not limiting, and which must be read in conjunction with the accompanying drawings, in which: [Figure 1] 1 is a schematic diagram of a known mineral fiber manufacturing facility; [Figure 2] 1 is a schematic diagram of a mineral fiber production facility according to one embodiment of the present invention; [Figure 3] FIG. 2 illustrates a schematic diagram of a method according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram illustrating the drawing of a filament according to one embodiment of the present invention. [Figure 5] FIG. 10 illustrates the change in momentum of mass flow versus total fuel flow entering the combustion chamber. [Figure 6] FIG. 10 illustrates the change in momentum of mass flow versus equivalence ratio of reactants injected into the combustion chamber. [Figure 7] FIG. 10 shows the variation of burner lip temperature with respect to the equivalence ratio of reactants injected into the combustion chamber. [Figure 8] FIG. 1 is a diagram illustrating a schematic of flame stabilization in a combustion chamber. [Figure 9] 1 is a schematic diagram of a portion of an injector according to an embodiment of the present invention; [Figure 10] 1 shows a schematic representation of a portion of a burner with an injector according to an embodiment of the present invention; [Figure 11] 2A and 2B are schematic diagrams illustrating gas flow in an injector and gas flow in a combustion chamber according to an embodiment of the present invention; [Figure 12] 1A and 1B show schematic diagrams of rings forming angular deflection elements according to an embodiment of the present invention; [Figure 13] 1A and 1B show schematic diagrams of rings forming angular deflection elements according to an embodiment of the present invention; [Figure 14] 1A and 1B show schematic diagrams of rings forming angular deflection elements according to an embodiment of the present invention;

[0018] In all figures, similar elements are labeled with the same reference numerals.

[0019] definition The "equivalence ratio φ" of a combustion reaction is defined as the ratio of the mass of fuel to the mass of air used in the combustion reaction on the one hand, and the ratio of the mass of fuel to the mass of air used in the same combustion reaction under stoichiometric conditions on the other hand. DETAILED DESCRIPTION OF THE INVENTION

[0020] 2 and 3, one aspect of the present invention is a method 300 for producing mineral fibers 1. The mineral fibers 1 are produced by an installation 2. The installation 2 comprises an annular burner 3. The annular burner 3 comprises a combustion chamber 4 and a nozzle 5. The nozzle 5 connects the combustion chamber 4 to the outside of the burner 3.

[0021] The installation 2 comprises a fiber spinner 6 with an orifice 7. The spinner 6 is suitable for receiving a molten thermoplastic material, in particular a mineral material, preferably glass. The spinner 6 is also suitable for forming filaments 8 of the molten thermoplastic material from the orifice 7 by centrifugal spinning of the spinner 6.

[0022] The method 300 includes a first step 301 of producing a filament. The first step 301 involves projecting molten thermoplastic material by centrifugal spinning onto the first annular wall 20 in a known manner. The material then flows into a plurality of holes 7 in the first annular wall 20 to form a filament 8 of material.

[0023] The method 300 includes a second step 302 of injecting a first fluid 9 into the combustion chamber 4 at a first flow rate. The first fluid 9 includes a fuel. The fuel includes dihydrogen. The volume fraction of dihydrogen in the first fluid 9 is greater than 0.15, in particular greater than 0.2, and preferably greater than 0.5. The fuel may also include at least one organic compound. The organic compound may be selected from methane, biogas, propane, and liquefied petroleum gas. The fuel may include a mixture of an organic compound and dihydrogen, preferably a mixture of methane and dihydrogen.

[0024] The method 300 includes a third step 303 of injecting a second fluid 10 into the combustion chamber 4 at a second flow rate. The second fluid 10 has an oxygen volume fraction greater than 0.1. Preferably, the second fluid 10 is air. The second step 302 and the third step 303 are preferably performed simultaneously.

[0025] The method 300 includes a fourth step 304 of combusting the fuel injected into the combustion chamber 4 in the second step and the oxygen injected into the combustion chamber 4 in the third step.

[0026] The method 300 comprises a fifth step of drawing the filaments 8. The nozzle 5 is arranged so that, after the combustion in the fourth step, the compounds contained in the combustion chamber 4 are discharged from the burner 3 through the nozzle, and the filaments 8 produced in the first step are then drawn to form the mineral fibers 1. Thus, by replacing some of the hydrocarbons used in the combustion with dihydrogen, it is possible to draw a certain amount of filaments to produce mineral fibers by centrifugal spinning, while reducing the amount of carbon dioxide produced.

[0027] Theoretical basis of the present invention The fuel may include methane and dihydrogen. The stoichiometric combustion reaction of a mixture containing methane and dihydrogen with air may be modeled by the following equation:

[0028]

number

[0029] The air-rich combustion reaction of a mixture containing methane and dihydrogen with air can be modeled by the following equation:

[0030]

number

[0031]

number

[0032] The supply amount AFR can be defined by the following formula:

[0033]

number

[0034] Ideal supply amount AFR st can be defined by the following formula:

[0035]

number

[0036] Therefore, the general equation for combustion involving methane and dihydrogen as fuels can be defined by the following equation:

[0037]

number

[0038] Therefore, in order to determine the composition of the combustion products, it is necessary to determine three parameters, namely, the amount of methane introduced into the combustion chamber 4, the amount of dihydrogen introduced into the combustion chamber 4, and λ. In addition, by calculating the molar enthalpies of the products and reactants in the above equation, the adiabatic flame temperature and the temperature of the lip 11 can be calculated from the above equation.

[0039] Stretching of filament 8 In a fifth step 305 of drawing the filament 8, the mineral fiber 1 is formed by applying an air force to the filament 8 driven by the compounds released from the combustion chamber 4 during combustion in the fourth step 304. The diameter of the mineral fiber 1 is controlled by the acceleration of the drawing caused by this air force.

[0040] With reference to FIG. 4, the stretching of the filament 8 is due to the areal density j of the momentum flow at the lip 11 of the burner 3. p The areal density j p is defined as follows:

[0041]

number

[0042] With reference to Figure 5, the momentum of the mass flow M B decreases with increasing dihydrogen content during combustion, determined by a constant equivalence ratio φ. Curve (a) shows the mass flow rate M relative to the total fuel flow rate when the equivalence ratio φ is 0.69 and the fuel contains only methane.B Curve (a) shows the relationship between the mass flow rate M and the total fuel flow rate when the equivalence ratio φ is 0.69 and the fuel contains 90% methane and 10% dihydrogen. B Curve (a) shows the mass flow rate M versus the total fuel flow rate when the equivalence ratio φ is 0.69 and the fuel contains 80% methane and 20% dihydrogen. B Curve (a) shows the relationship between the mass flow rate M and the total fuel flow rate when the equivalence ratio φ is 0.69 and the fuel contains 70% methane and 30% dihydrogen. B Curve (a) shows the relationship between the mass flow rate M and the total fuel flow rate when the equivalence ratio φ is 0.69 and the fuel contains only dihydrogen. B Shows.

[0043] Mass flow momentum M B is defined by the following formula:

[0044]

number

[0045] Thus, the pressure P in the combustion chamber 4 B The extension of the filaments 8 is controlled by the pressure P BThe pressure is 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq), in particular 4413 Pa (450 mmAq) to 7355 Pa (750 mmAq), preferably 5394 Pa (550 mmAq) to 6374 Pa (650 mmAq). In this way, mineral fibers 1 having a fineness of 3 L / min to 24 L / min, in particular 6 L / min to 20 L / min, can be produced at least in part using dihydrogen as fuel. The rotation speed of the spinner can be higher than 2000 rpm. The amount of fiber drawn by the spinner can be less than 1 kg per day per orifice 7 of the spinner 6, in particular less than 0.6 kg per day per orifice 7 of the spinner 6.

[0046] The combustion defined by the fourth step 304 is preferably continuous. Thus, in the fourth step 304, the pressure P B The pressure can be maintained at 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq). "Maintained" means that the pressure is maintained for more than 10 minutes, particularly more than 1 hour, and preferably more than 3 hours.

[0047] Pressure P in the combustion chamber 4 B can be determined by the geometry of the combustion chamber 4, the geometry of the nozzle 5, the first flow rate, the second flow rate, the composition of the first fluid 9, and the composition of the second fluid 10. For example, the combustion chamber 4 and nozzle 5 described in WO 03 / 069226 can be used. The combustion reaction in the combustion chamber 4 can be maintained by introducing a mass flow rate of 9.96 kg / h of methane, a mass flow rate of 0.75 kg / h of dihydrogen, thus a volume fraction of dihydrogen in the first fuel of 0.07, and a mass flow rate of 285 kg / h of a second fluid consisting of air. The above-described combustion reaction can produce a flow rate of 18.9 kg m / s in the spinner. 2 Mass flow rate M B is applied, while the pressure P B is controlled to be 6002 Pa (612 mmAq).

[0048] The system may include a control unit configured to control a first flow rate of the first fluid and a second flow rate of the second fluid to control a pressure P in the combustion chamber. B The pressure P can be set to 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq), particularly 4413 Pa (450 mmAq) to 7355 Pa (750 mmAq), and preferably 5394 Pa (550 mmAq) to 6374 Pa (650 mmAq). In this way, the present equipment can produce mineral fibers 1 having a fineness of 3 L / min to 24 L / min, particularly 6 L / min to 20 L / min, using dihydrogen as fuel at least in part. The pressure P B The pressure P B may also be measured by a pressure sensor, which may be selected from a pitot tube and a sensor located on the burner lip configured to emit a signal representative of the pressure in the combustion chamber.

[0049] There may be a combustion ignition step before the fourth step 304. During the combustion ignition step, the pressure P B The pressure may be 0 Pa (0 mmAq) to 1961 Pa (200 mmAq).

[0050] The spinner has a diameter of D A and the nozzle has a cross-sectional diameter D T The pressure P in the combustion chamber 4 B is as defined above, the average momentum of the compound passing through the nozzle cross section in the fifth step is 2π D T ·1961·(D A +D T )~2π·D T 7354 (D A +D T ), especially 2π D T 4413 (D A +D T )~2π·D T 7355 (D A +D T ), preferably 2π D T5393 (D A +D T )~2π·D T 6374 (D A +D T ) Diameter D T is 7.7 mm, and the diameter of the spinner D A is 400 mm, the average momentum of the compound passing through the nozzle cross section during the fifth step is 38.7 kg m s -2 ~154kg·m·s -2 , especially 87.0 kg m s -2 ~145kg m s -2 , preferably 106 kg m s -2 ~126 kg·m·s -2 The diameter D T is 7.7 mm, and the diameter of the spinner D A is 600 mm, the average momentum of the compound passing through the nozzle cross section during the fifth step is 57.7 kg m s -2 ~231 kg·m·s -2 , especially 130 kg m s -2 ~216 kg·m·s -2 , preferably 159 kg m s -2 ~187 kg·m·s -2 It may be.

[0051] Combustion equivalence ratio 6, the equivalence ratio φ of the mass formed by the mixture of the first fluid 9 and the second fluid 10 in the combustion chamber 4 is between 0.40 and 0.90, in particular between 0.50 and 0.80, preferably between 0.60 and 0.70. In this way, the mass flow density M resulting from the use of dihydrogen during combustion B The decrease in mass flow density M can be compensated for by injecting a higher proportion of the second fluid 10 into the chamber 4. This will ensure that the mass flow density M is sufficient to elongate the filaments 8 formed by centrifugal spinning. B It is possible to realize combustion using dihydrogen as fuel while generating the above. If the equivalence ratio is less than 0.40, the stability of the flame in the combustion chamber 4 during combustion cannot be guaranteed. If the equivalence ratio exceeds 0.90, the mass flow density M BBecause φ is too low, the filaments 8 cannot be drawn to form mineral fibers 1, and fuel is present in the exhausted compounds, which causes pollution. Figure 6 shows the mass flow density M versus equivalence ratio φ for a dihydrogen to methane molar ratio of 0.43. B The equivalence ratio φ of the combustion reaction in the fourth step 304 may be determined by the first flow rate, the second flow rate, the composition of the first fluid 9, and the composition of the second fluid 10.

[0052] Burner 3, 1 lip 11 temperature With reference to FIG. 7 , at least one lip 11 defines a boundary between the nozzle 5 and the outside of the burner 3. The temperature of the lip 11 can be calculated depending on the reactants introduced into the combustion chamber, taking into account the reaction equations presented above and the molar enthalpies of the various reactants and products involved in the reaction. Curve (f) shows the temperature of the lip 11 versus the equivalence ratio φ of the combustion reaction when the volume fraction of dihydrogen is 0 and the volume fraction of methane is 1. Curve (g) shows the temperature of the lip 11 versus the equivalence ratio φ of the combustion reaction when the volume fraction of dihydrogen is 0.11 and the volume fraction of methane is 0.89. Curve (h) shows the temperature of the lip 11 versus the equivalence ratio φ of the combustion reaction when the volume fraction of dihydrogen is 0.25 and the volume fraction of methane is 0.75. Curve (i) shows the temperature of the lip 11 versus the equivalence ratio φ of the combustion reaction when the volume fraction of dihydrogen is 0.43 and the volume fraction of methane is 0.57. Curve (j) shows the temperature of lip 11 versus the equivalence ratio φ of the combustion reaction when the volume fraction of dihydrogen is 1 and the volume fraction of methane is 0.

[0053] In the fourth step 304, the temperature measured at lip 11 can be between 1100°C and 1600°C, particularly between 1200°C and 1550°C, and preferably between 1300°C and 1550°C. The volume fraction and / or equivalence ratio of dihydrogen in the fuel can be adjusted so that the temperature measured at lip 11 is within the range specified above. Preferably, the equivalence ratio φ of the aggregate formed by the mixture of first fluid 9 and second fluid 10 in combustion chamber 4 is between 0.40 and 0.90, particularly between 0.50 and 0.80, and preferably between 0.60 and 0.70, and the temperature measured at lip 11 can be between 1100°C and 1600°C, particularly between 1200°C and 1550°C, and preferably between 1300°C and 1550°C. The inventors have indeed found that the combination of these various parameters and the use of dihydrogen as fuel makes it possible to produce mineral fibers 1 by centrifugal spinning. The temperature measured at lip 11 can be maintained between 1100°C and 1600°C during the fourth combustion step 304.

[0054] flame stability With reference to Figure 8, the composition of the first fluid 9 and the composition of the second fluid 10 determine the flame speed Sf during the fourth combustion step 304. The term "flame speed" refers to the rate at which a flame front develops during a combustion reaction. The flame speed depends on the rate at which fuel and oxidizer are consumed in the combustion reaction. The first fluid 9 and the second fluid 10 may be mixed, preferably in a burner, before being introduced into the combustion chamber to form a mixture. The mixture may be injected into the combustion chamber 4 in the second step 302 and the third step 303. The average velocity U of the mixture upon injection into the combustion chamber 4 is determined by the flame speed Sf. f This prevents flashback during the combustion reaction. In fact, if the flame speed Sf is higher than the average speed U, the flame will move towards the source of the mixture, creating a risk of explosion and burner damage.

[0055] Initial pressure of the first fluid 9 The first fluid 9 and the second fluid 10 may be mixed, preferably in the burner 3, before being injected into the combustion chamber 4. The mixture injected into the combustion chamber 4 may have a pressure of greater than 102,000 Pa, preferably greater than 103,000 Pa. By increasing the pressure of the mixture, the temperature of the mixture may be increased prior to combustion. This increases the adiabatic flame temperature upon combustion, and therefore reduces the production of carbon dioxide at a given adiabatic flame temperature.

[0056] Mixing of the first fluid 9 and the second fluid 10 The first fluid 9 and the second fluid 10 can be mixed in the burner 3 before being introduced into the combustion chamber 4. This allows the compounds of the first fluid 9 and the second fluid 10 to be distributed evenly in the combustion chamber 4, while avoiding the risk of combustion outside the burner 3 that may occur due to the first fluid 9 and the second fluid 10 mixing upstream of the burner 3.

[0057] 9, the burner 3 may include an injector 12. The injector 12 includes a first fluid inlet 9, a second fluid inlet 10, and a mixing duct 13 fluidly connected to the first fluid inlet 9 and the second fluid inlet 10. A side duct 24 fluidly connects the first fluid inlet 9 to the mixing duct 13. The injector 12 includes an outlet 28 that separates the mixing duct 13 from the combustion chamber 4.

[0058] The geometry of the injector 12 is configured such that when the first fluid 9 and the second fluid 10 are injected into the injector 12, they flow along at least a portion of the mixing duct 13 in the same main flow direction 14, causing the second fluid 9 to exhibit rotation relative to the first fluid 10 about an axis oriented in the main flow direction 14. As a result, the densities of the first fluid 9 and the second fluid 10 are more uniform in the combustion chamber 4 than in the absence of the injector 12 as defined above. This improves flame stability during combustion. In fact, it may be advantageous to perform the method in a "lean" mode, i.e., with an equivalence ratio of less than 0.9. If the first fluid 9 and the second fluid 10 are not uniformly distributed in the combustion chamber 4, the equivalence ratio may locally be much lower than the equivalence ratio predetermined by the flow rates of the first fluid 9 and the second fluid 10, which may induce flame instability.

[0059] The injector 12 comprises an angular deflection element 15 adapted to generate a swirling flow of the first fluid 9 and / or the second fluid 10 in the mixing duct 13. The angular deflection element 15 thus enables the first fluid 9 and the second fluid 10 to flow along at least a portion of the mixing duct 13 in the same main flow direction 14, thereby achieving a flow in which the second fluid 9 exhibits a rotation relative to the first fluid 10 about an axis oriented in the main flow direction 14. The angular deflection element 15 may be adapted to generate a swirling flow of the first fluid 9 or the second fluid 10 in the mixing duct 13.

[0060] 12, 13 and 14, the angular deflection element 15 may have a swirl number S that satisfies the equation S=2 / 3tan(Ψ), where Ψ is the angle of angular deflection of the flow of the first fluid 9 and / or second fluid 10 after passing through the injector 15. The swirl number S is between 0.10 and 2.00, preferably between 0.25 and 1.70, even more preferably between 0.35 and 1.40, even more preferably between 0.45 and 1.10, even more preferably between 0.50 and 0.90, and even more preferably between 0.65 and 0.70.

[0061] The strength of the rotational motion of the flow is characterized by the value of the swirl number S at the exit of the injector 12. The swirl number S defines the ratio of the tangential momentum flow to the axial momentum flow. The swirl number S can be defined by the following equation:

[0062]

number

[0063] Increasing the swirl number S reduces the flame height and increases the flame spread, which makes it possible to reduce the number of injectors located around the periphery of the combustion chamber 4 while still ensuring uniform heating of the combustion chamber 4.

[0064] 10 and 11, at least part of the angular deflection element 15 can be formed by an annular body arranged coaxially with the main flow direction 14. The annular body can be removable. The annular body can be provided with a duct adapted to allow a swirling flow of the first fluid 9 and / or the second fluid 10 to be introduced into the mixing duct 13 of the injector 12 at an angular deflection angle Ψ of preferably 10° to 80°, in particular 20° to 70°, even more preferably 30° to 60°, and even more preferably 40° to 50°. This allows maximizing the mixing of the first fluid 9 and the second fluid 10 before introduction into the combustion chamber 4. This allows reducing the amount of fuel injected for the same amount of oxidizer involved in combustion. The duct adapted to allow the introduction of a swirling flow can form part of the side duct 24.

[0065] The angular deflection element may be a set of deflectors arranged in the mixing duct 13 to rotate the flow of the first fluid 9 and the second fluid 10 along an axis following the main direction 14 .

[0066] 10 , the burner 3 is configured to separately supply the first fluid 9 and the second fluid 10 to the injector 12. The burner 3 may have a first inlet 26 for the first fluid 9. The injector 12 may have an axial duct 25 fluidly connecting the first inlet 26 to the mixing duct 13. The burner 3 may have a second inlet 27 for the second fluid 10. The second inlet 27 may be connected to the lateral duct 24. The mixture of the first fluid 9 and the second fluid 10 is treated in the mixing duct 13 before being injected into the combustion chamber 4 of the burner 3. By separating the first inlet 26 and the second inlet 27 in this way, it is possible to prevent flashback upstream of the burner 3.

[0067] 11, the walls of the side ducts 24 may have a frustoconical shape with a major axis along the main direction 14. The diameter of the frustoconical shape may decrease along the main direction 14. This may prevent the boundary layer from separating from the swirling flow, thereby reducing the risk of undesired turbulence.

[0068] The second fluid 10 may be preheated, preferably by at least 5°C, before being injected into the burner 3. The preheating of the second fluid 10 may be achieved by recovering heat from the combustion gases of the fourth step 304 and / or by recovering heat from the glass melting furnace.

[0069] The swirl created in the mixing duct 13 creates fluid recirculation within the combustion chamber 4. This recirculation allows the flame generated during combustion to establish itself in the combustion chamber 4 near the injector outlet. The presence of a toroidal recirculation zone enhances flame retention. This toroidal recirculation zone returns a portion of the combustion gases to the injector outlet, thereby preheating the gases exiting the injector 12. This makes the flame more stable, allowing for a reduction in the amount of fuel used for combustion without the risk of flame blowout.

[0070] The axial duct 25 may have an outlet in the mixing duct 13. The distance between the outlet of the axial duct 25 and the outlet of the injector 13 may be strictly 0 to 45 mm. If this distance is less than 45 mm, mixing efficiency can be improved. Furthermore, since this distance is strictly greater than zero, injector wear caused by high combustion temperatures can be suppressed. In particular, this distance is greater than 5 mm, preferably greater than 10 mm, more preferably greater than 15 mm, and most preferably greater than 20 mm.

[0071] The outlet of the injector 12 can have a straight section. By "straight section" we mean that the outlet of the injector 12 is formed by the wall of the mixing duct 13 at the same point in the main direction 14. The inventors have found that beveling the injector at the gas outlet, as done in the prior art, tends to disrupt the swirling circulation of the oxidizer / fuel mixture, thus reducing the beneficial technical effects associated with such swirling circulation. In contrast, cutting the injector outlet into a straight section improves flame stability during combustion.

[0072] The combustion chamber 4 is defined by at least one wall. The wall has a distal portion. The outlet 28 can be located in the center of the distal portion relative to the main axis X. In this manner, the outlet is located equidistant from the upper and lower walls of the combustion chamber 4, which results in a more uniform and stable flame due to gas recirculation.

[0073] The cross section of the outlet 28 can have a suitable diameter determined by the stabilization distance between the flame and the outlet 28. The smaller this diameter, the higher the mixture flow rate at the outlet 28, which increases the flame stabilization distance. In that case, the flame is said to be "lifted." Above a certain injection velocity, the flame will be in a "blowout" state. Conversely, the larger this diameter, the lower the flow rate at the outlet 28. Below a certain mixture flow rate at the outlet 28, there is a risk of flame stabilization inside the injector 12, which should be avoided.

[0074] The burner 3 may comprise a plurality of injectors 12. The burner 3 may comprise an annulus for distributing the first fluid 9 and / or the second fluid 10 to the injectors 12. The annulus may comprise inlets uniformly distributed around its periphery. The number of inlets may be equal to the number of injectors. In this way, the fluid flow may be uniform within the injectors 12. Increasing the number of inlets in the annulus increases the uniformity of the fluid distribution within the injectors.

Claims

1. A method for producing mineral fibers (1) using an installation (2), the installation (2) comprising: an annular burner (3) comprising a combustion chamber (4) and a nozzle (5) by means of which the combustion chamber (4) is connected to the outside of the burner (3); a fibre spinner (6) provided with an orifice (7), said fibre spinner (6) being suitable for receiving molten mineral material and for forming filaments (8) of said mineral material from said orifice (7) by centrifugal spinning of said spinner (6); It is equipped with The method comprises at least the following steps: a first step of manufacturing said filaments (8), a second step of injecting a first fluid (9) into said combustion chamber (4) at a first flow rate, said first fluid (9) comprising a fuel; a third step of injecting a second fluid (10) into said combustion chamber (4) at a second flow rate, said second fluid (10) having an oxygen volume fraction greater than 0.10; a fourth step of combusting the fuel and oxygen introduced into the combustion chamber (4) in the second and third steps; a fifth step of drawing the filaments (8), the nozzle (5) being arranged so that, after the combustion in the fourth step, the compounds contained in the combustion chamber (4) are discharged from the burner (3) through the nozzle, and then the filaments (8) produced in the first step are drawn to form the mineral fibres (1); In a method comprising: the fuel comprises dihydrogen, and the volume fraction of dihydrogen in the first fluid (9) is greater than 0.05; In the fourth step, the pressure P in the combustion chamber Ｂ is 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq) A method characterized by:

2. In the fourth step, the pressure P in the combustion chamber Ｂ 2. The method of claim 1, wherein the pressure is between 450 mmAq and 750 mmAq, preferably between 550 mmAq and 650 mmAq.

3. The method according to claim 1 or 2, wherein the equivalence ratio φ of the mixture of the first fluid (9) and the second fluid (10) in the combustion chamber (4) is between 0.40 and 0.

90.

4. The method according to any one of claims 1 to 3, wherein the fuel comprises an organic compound, in particular methane.

5. 5. The method according to any one of claims 1 to 4, wherein a lip (11) defines the boundary between the nozzle (5) and the outside of the burner (3), and in the fourth step, the temperature measured at the lip (11) is between 1100°C and 1600°C.

6. the composition of the first fluid (9) and the composition of the second fluid (10) determine the flame speed Sf during the fourth combustion step; said first fluid (9) and said second fluid (10) are mixed preferably in said burner (3) before being introduced into said combustion chamber (4) to form a mixture, and said mixture is injected into said combustion chamber (4) during said second step and said third step; The average velocity U of the mixture when injected into the combustion chamber (4) is ｆ The method according to any one of claims 1 to 5.

7. 7. The method according to any one of claims 1 to 6, wherein the first fluid (9) and the second fluid (10) are mixed, preferably in the burner (3), to form a mixture (4) before being introduced into the combustion chamber (4), said mixture having a pressure of more than 102,000 Pa, preferably more than 103,000 Pa.

8. A method according to any one of the preceding claims, wherein the first fluid (9) and the second fluid (10) are mixed in the burner (3) before being introduced into the combustion chamber (4).

9. the burner (3) comprises an injector (12), the injector (12) comprising a first fluid inlet (9), a second fluid inlet (10), a mixing duct (13) fluidly connected to the first fluid inlet (9) and the second fluid inlet (10), and an outlet fluidly connecting the mixing duct (13) to the combustion chamber (4); 9. The method of claim 8, wherein the geometry of the injector (12) is configured such that when injecting the first fluid (9) and the second fluid (10) into the injector (12), the first fluid (9) and the second fluid (10) flow along at least a portion of the mixing duct (13) in the same main flow direction (14), thereby causing the second fluid (9) to exhibit a rotation relative to the first fluid (10) about an axis oriented in the main flow direction (14).

10. 10. The method according to claim 9, wherein the injector (12) comprises an angular deflection element (15) adapted to generate a swirling flow of the first fluid (9) and / or the second fluid (10) in the mixing duct (13).

11. 8. The method according to any one of claims 1 to 7, wherein the volume fraction of dihydrogen in the first fluid (9) is between 0.15 and 0.2, and wherein the first fluid (9) and the second fluid (10) are mixed before being injected into the burner (3).

12. 11. The method according to claim 9 or 10, wherein the burner (3) is configured to supply the injector (12) with a first fluid (9) and a second fluid (10) separately.

13. An installation (2) for producing mineral fibers (1), said installation comprising: an annular burner (3) comprising a combustion chamber (4) and a nozzle (5) by means of which the combustion chamber (4) is connected to the outside of the burner (3); a fibre spinner (6) provided with an orifice (7), said fibre spinner (6) being suitable for receiving molten mineral material and for forming filaments (8) of said mineral material from said orifice (7) by centrifugal spinning of said spinner (6); It is equipped with The burner (3) comprises: a first inlet (26) configured to receive a first fluid (9) at a first flow rate, said first fluid (9) comprising a fuel, said fuel comprising dihydrogen, a volume fraction of dihydrogen in said first fluid (9) greater than 0.05, said first inlet (26) being fluidly connected to said combustion chamber (4); a second inlet (27) configured to receive a second fluid (10) at a second flow rate, said second fluid (10) having an oxygen volume fraction greater than 0.10, said second inlet (27) being fluidly connected to said combustion chamber (4); It is equipped with The facility includes a control unit, and the control unit controls the first flow rate of the first fluid and the second flow rate of the second fluid in relation to a pressure P Ｂ The equipment (2) is configured to control the pressure so that the pressure is 1961 Pa (200 mmAq) to 7845 Pa (800 mmAq).

14. The installation comprises an injector (12) having a first fluid inlet (9), a second fluid inlet (10), a mixing duct (13) fluidly connected to the first fluid inlet (9) and the second fluid inlet (10), and an outlet fluidly connecting the mixing duct (13) to the combustion chamber (4); the first inlet (26) of the burner (3) is fluidly connected to the first fluid inlet (9) of the injector (12); the second inlet (27) of the burner (3) is fluidly connected to the second fluid inlet (10) of the injector (12); 14. The installation according to claim 13, wherein the geometry of the injector (12) is configured such that when injecting the first fluid (9) and the second fluid (10) into the injector (12), the first fluid (9) and the second fluid (10) flow along at least a portion of the mixing duct (13) in the same main flow direction (14), such that the second fluid (9) exhibits a rotation relative to the first fluid (10) about an axis oriented in the main flow direction (14).

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