BURNER FOR INDUSTRIAL OVEN

Abstract

BURNER FOR INDUSTRIAL FURNACE One aspect of the invention relates to a burner (1) for an industrial furnace, comprising a fuel distribution device (3) and an oxidant distribution device (6) directly actuated by means of a drive shaft (12). Figure to be published with the abstract: Figure 1

Description

Title of the invention: BURNER FOR INDUSTRIAL FURNACE TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to the general technical field of heat generation installations for industrial processes, and more specifically to devices for supplying fuel and oxidant to such installations. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Heat generation installations, including burners in particular, conventionally comprise a fuel supply circuit and an oxidant supply circuit configured to supply a fuel injection circuit and an oxidant injection circuit of the burner respectively. The fuel and the oxidant are injected by the burner in proportions controlled as a function of various physical parameters, including the nature of the fuel, the power and the temperature to be reached by the burner.

[0003] Due to the known proportionality ratio between the fuel flow rate and the oxidant flow rate during standardized operation of the burner, it has been conventionally proposed to provide joint control of the fuel and oxidant supply circuits. A single actuator provides a distributed force to an effector located in the fuel supply circuit and an effector located in the oxidant supply circuit, the effector being configured to vary the fuel or oxidant flow rate in the respective supply circuit.

[0004] Such a solution therefore makes it possible to respect in all circumstances the proportion of fuel and oxidant flow rates, defined during the design of the burner, during a modification of said flow rates.

[0005] Conventionally, the effectors located respectively in the fuel supply circuit and in the oxidant supply circuit are of the throttle body type, comprising a body defining a portion of pipe, a closure element extending into the pipe, a lever rotatably mounted in the body and connected to the closure element, such that an action on the lever causes a movement of the closure element modifying the area of ​​the passage section of the portion of pipe.

[0006] These solutions, however, present the problem of non-linearity between the control signal and the change in flow rate caused by the control, which can be compensated by the use of a cam profile, which complicates the device and increases the size, making its integration into compact burners complex.

[0007] There is therefore a need to simplify this type of device in order to allow integration into a greater number of types of installations. Summary of the invention

[0008] In order to address the limitations of the prior art, the invention proposes a burner for an industrial furnace comprising a fuel supply assembly and an oxidant supply assembly, the fuel supply assembly comprising from upstream to downstream a fuel inlet manifold configured to receive the fuel, a fuel distribution device configured to control a fuel flow rate, and a fuel injection device, configured to inject fuel into the furnace, the oxidant supply assembly comprising an oxidant inlet manifold configured to receive the oxidant, an oxidant distribution device configured to control an oxidant flow rate, and an oxidant injection device, configured to inject oxidant into the furnace, wherein: - the oxidant distribution device comprises a movable shutter through which a first opening is provided, a stator through which a second opening is provided, a drive shaft secured to the movable shutter capable of rotating the movable shutter, the movable shutter being located opposite the stator in such a way that, when it is driven by the drive shaft, the first opening is positioned at least partially opposite the second opening so as to create an oxidant passage putting the oxidant intake manifold and the oxidant injection device into fluid communication, the first opening and the second opening being shaped so that the oxidant passage has a cross-section of variable surface area depending on the angular position of the drive shaft, - the fuel distribution device comprises a fixed element comprising an inlet connected to the fuel intake manifold, an outlet connected to the fuel injection device, a second movable shutter rotatably mounted in the fixed element, the second movable shutter comprising a wall defining a cavity opening at the outlet into the fuel injection device, the wall closing the inlet of the fixed element, a light being provided through the wall so as to form a lateral opening, the second movable shutter being integral with the drive shaft in such a way that, when the drive shaft is rotated, the light is positioned partially opposite the inlet of the fixed element so as to create a fuel passage fluidically connecting the fuel intake manifold and the cavity connected to the fuel injection device,the light and the entrance, being shaped so that the fuel passage has a cross-section of variable surface area depending on the angular position of the drive shaft.

[0009] Such a burner therefore makes it possible to vary the flow rate of fuel and oxidant proportionally by means of a single moving element, which greatly limits the size and complexity of such a device.

[0010] Advantageously, such a burner can be supplemented by the following characteristics, taken alone or in combination:

[0011] - the first opening has the shape of an angular portion of an annular element, and the second opening has a shape of an angular portion of an annular element;

[0012] - the light has a shape such that the projection onto a plane of the light forms an angular portion of a disc;

[0013] - the angular position of the light and the angular positions of the first opening and the second opening are configured so that rotation of the drive shaft causes a simultaneous and proportional change in the respective surfaces of the fuel passage and the oxidizer passage;

[0014] - the drive shaft extends along a main axis of the burner, the shutter mobile and the second mobile shutter being coaxial and extending along the main axis;

[0015] - the stator comprises a disc comprising an opening in which is mounted a mixer comprising a perforated grid configured to generate turbulence in the flow of the oxidant stream;

[0016] - the drive shaft comprises an adjustably mounted outer sleeve on an inner shaft and extending outwardly of the inner shaft, the inner shaft extending through an opening provided through the movable shutter and the stator and being secured to the second movable shutter, the outer sleeve being connected to the movable shutter in a sealing manner;

[0017] - the drive shaft extends along a main axis of the burner, the shutter mobile and the mobile shutter being coaxial and extending along the main axis;

[0018] - the stator is a disc comprising an opening in which is mounted a mixer;

[0019] BRIEF DESCRIPTION OF THE FIGURES

[0020] The figures are presented for information purposes only and in no way limit the invention.

[0021] [Fig. 1] is a schematic sectional side view of a burner according to the invention.

[0022] [Fig.2a] is an axial sectional view highlighting a dispensing device of oxidant according to the invention, in a partially open position.

[0023] [Fig.2b] is an axial sectional view highlighting a dispensing device of oxidant according to the invention, in an open position.

[0024] [Fig.3] is an axial view showing a movable shutter of an oxidant distribution device according to the invention.

[0025] [Fig.4a] is a 3D view showing a movable shutter of a device for fuel distribution according to the invention.

[0026] [Fig.4b] is a side sectional view showing a movable shutter of a fuel distribution device according to the invention. DETAILED DESCRIPTION

[0027] With reference to [Fig.l], the invention relates to a burner 1 for an industrial furnace extending along a main axis X, comprising a fuel supply assembly and an oxidant supply assembly. In this description, the concepts of upstream and downstream refer to the circulation of gases in the burner in a normal operating mode, and the concepts of axial, radial and tangential refer to a cylindrical reference frame of axis X. The fuel supply assembly comprises from upstream to downstream an intake manifold 2 configured to receive the fuel, a fuel distribution device 3 configured to allow or block the circulation of fuel, and control a fuel flow rate, and a fuel injection device 4, configured to inject fuel into the furnace.The oxidant supply assembly comprises an oxidant inlet manifold 5 configured to receive the oxidant, an oxidant distribution device 6 configured to allow or block the flow of oxidant, as well as control a flow rate of oxidant, and an oxidant injection device 7, configured to inject oxidant into the furnace.

[0028] With reference to figures 2a, 2b, the oxidant distribution device 6 comprises a movable shutter 8, through which a first opening 9 is provided, a stator 10 through which a second opening 11 is provided, a drive shaft 12 extending along the main axis X secured to the movable shutter 8 and capable of driving the movable shutter 8 in rotation.The movable shutter 8 is located opposite the stator 10, in contact with the stator 10, in such a way that, when the movable shutter 8 is rotated by the drive shaft 12, the first opening 9 is positioned at least partially opposite the second opening 11 so as to create an oxidizer passage putting the oxidizer intake manifold 5 and the oxidizer injection device 7 into fluid communication, the first opening 9 and the second opening 11 being shaped so that the oxidizer passage has a cross section of variable surface area depending on the angular position of the drive shaft 12.

[0029] The fuel distribution device 3 comprises a fixed element 13 defining a cavity comprising an inlet 14 in connection with the fuel intake manifold 2, an outlet 15 in connection with the fuel injection device 4 and a second movable shutter 16 rotatably mounted in the fixed element 13. The second movable shutter 16 comprises a wall 17 defining a cavity opening at the outlet 15 into the fuel injection device 4, the wall 17 closing the inlet 14 of the fixed element 13. A light 18 is provided through the wall 17 so as to form a lateral opening of the movable shutter 16.The second movable shutter 16 is connected to the drive shaft 12 in such a way that, when the drive shaft 12 is rotated, the port 18 is positioned partially opposite the inlet 14 of the fixed element 13 so as to create a fuel passage fluidically connecting the intake manifold 2 and the fuel injection device 4, the port 18 and the inlet 14 being shaped so that the fuel passage has a cross-section of variable surface area depending on the angular position of the drive shaft 12.

[0030] Such a configuration makes it possible to modify simultaneously, using the same actuator, the fuel and oxidant flow rates, while greatly limiting the number of moving components and the size of the fuel supply assembly and the oxidant supply assembly.

[0031] Advantageously, with reference to [Fig.3], the movable shutter 8 comprises a first X-axis disc through which the first opening 9 is formed, and the stator 10 comprises a second X-axis disc through which the second opening 11 is formed. The first opening 9 has the shape of an angular portion of an annular element, and the second opening 11 has the shape of an angular portion of an annular element. Thus, by modifying the annular position of the drive shaft 12 to gradually make the first opening 9 and the second opening 11 coincide, a change in the angular position of the drive shaft 12 causes a linear change in the surface area of ​​the cross-section of the oxidant passage. This makes it possible to achieve a proportional response of the increase in the flow rate, and therefore of the heating power, as a function of the control in the angular position of the drive shaft 12.

[0032] Advantageously, the stator 10 comprises a mixer 19 configured to generate turbulence in the flow of the oxidant flow and promote the mixing of the oxidant and the fuel. In the embodiment illustrated in FIGS. 2a and 2b, the mixer 19 comprises a pierced grid located at the second opening 11. When the first opening 9 and the second opening 11 coincide in a manner to form an oxidant passage, the oxidant thus circulates through the mixer 19 and the flow of the oxidant becomes turbulent.

[0033] With reference to Figures 3 and 4, the light 18 has a shape such that the projection onto a plane, in particular onto a plane passing through the main axis X of the light 18 as shown in [Fig.4b], forms an angular portion of a disc. Such a geometry makes it possible, when the angular position of the drive shaft 12 is modified, to achieve an increase in the surface area of ​​the cross-section of the fuel passage proportional to the angular position of the drive shaft 12.

[0034] Advantageously, the angular position of the light 18 and the angular positions of the first opening 9 and the second opening 11 are configured so that the rotation of the drive shaft 12 causes a simultaneous and proportional modification of the respective surfaces of the cross sections of the fuel passage and the oxidizer passage.

[0035] Advantageously, the drive shaft 12 comprises an outer sleeve 20 mounted in a rotatable manner on an inner shaft 21 and extending outside the inner shaft 21, the inner shaft 21 extending through an opening provided through the movable shutter 8 and the stator 10 and being fixed to the movable shutter 16, the outer sleeve 20 being connected to the movable shutter 8. Adjusting the relative angular position between the outer sleeve 20 and the inner shaft 21 makes it possible to create an offset between the angular position from which the movable shutter 8 allows the oxidant to circulate, and the angular position from which the movable shutter 16 allows the fuel to circulate. This thus makes it possible to adjust the excess air in the gas mixture injected into the burner 1.

Claims

1. Claims Burner (1) for an industrial furnace comprising a fuel supply assembly and an oxidant supply assembly, the fuel supply assembly comprising from upstream to downstream a fuel inlet manifold (2) configured to receive the fuel, a fuel distribution device (3) configured to control a fuel flow rate, and a fuel injection device (4), configured to inject fuel into the furnace, the oxidant supply assembly comprising an oxidant inlet manifold (5) configured to receive the oxidant, an oxidant distribution device (6) configured to control an oxidant flow rate, and an oxidant injection device (7), configured to inject oxidant into the furnace, wherein: - the oxidant distribution device (6) comprises a movable shutter (8) through which a first opening (9) is provided, a stator (10) through which a second opening (11) is provided, a drive shaft (12) secured to the movable shutter (8) capable of rotating the movable shutter (8), the movable shutter (8) being located opposite the stator (10) in such a way that, when it is driven by the drive shaft (12), the first opening (9) is positioned at least partially opposite the second opening (11) so as to create an oxidant passage putting the oxidant intake manifold (5) and the oxidant injection device (7) into fluid communication, the first opening (9) and the second opening (11) being shaped so that the oxidant passage has a cross-section of variable surface area depending on the angular position of the drive shaft (12), - the fuel distribution device (3) comprises a fixed element (13) comprising an inlet (14) in connection with the fuel intake manifold (2), an outlet (15) in connection with the fuel injection device (4), a second movable shutter (16) rotatably mounted in the fixed element (13), the second movable shutter (16) comprising a wall (17) defining a cavity opening at the outlet (15) into the fuel injection device (4), the wall (17) closing the inlet (14) of the fixed element (13), a light (18) being provided through the wall (17) so as to form a lateral opening, the second movable shutter (16) being integral with the drive shaft (12) in such a way that, when the drive shaft (12) is rotated, the light (18) is positioned partially opposite the inlet (14) of the fixed element (13) so as to create a fuel passage fluidically connecting the fuel intake manifold (2) and the cavity connected to the fuel injection device (4), the light (18) and the inlet (14) being shaped so that the fuel passage has a cross-section of variable surface area depending on the angular position of the drive shaft (12).

2. Burner (1) according to claim 1, wherein the first opening (9) has a shape of an angular portion of an annular element, and wherein the second opening (11) has a shape of an angular portion of an annular element.

3. Burner (1) according to one of claims 1 and 2, in which the light (18) has a shape such that the projection of the light (18) on a plane forms an angular portion of a disc.

4. Burner (1) according to one of the preceding claims, wherein the angular position of the light (18) and the angular positions of the first opening (9) and the second opening (11) are configured so that the rotation of the drive shaft (12) causes a simultaneous and proportional modification of the respective surfaces of the cross sections of the fuel passage and the oxidant passage.

5. Burner (1) according to one of the preceding claims, wherein the drive shaft extends along a main axis (X) of the burner, the movable shutter (8) and the second movable shutter (16) being coaxial and extending along the main axis (X).

6. Burner according to one of the preceding claims, in which the stator (10) comprises a disc comprising an opening in which is mounted a mixer (19) comprising a perforated grid configured to generate turbulence in the flow of the oxidant flow.

7. Burner (1) according to one of the preceding claims, wherein the drive shaft (12) comprises an outer sleeve (20) adjustably mounted on an inner shaft (21) and extending

8. the exterior of the inner shaft (21), the inner shaft (21) extending through an opening provided through the movable shutter (8) and the stator (10) and being fixed to the second movable shutter (16), the outer sleeve (21) being connected to the movable shutter (8). Burner (1) according to claim 7, wherein the outer sleeve (20) is adjustable in rotation relative to the inner shaft (21).

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