Gas burner with multiple gas ejection nozzles

Abstract

The invention relates to a gas burner (5) for an industrial furnace (1), comprising: - gas supply circuits (20) and air supply circuits (31), - a first and a second ejection nozzle (41, 51), connected to a respective end of a first and a second nozzle (40, 50) extending along a respective longitudinal axis (X1, X2), and having respectively a first through orifice (43), oriented parallel to the first longitudinal axis (X1), and a second through orifice (53) transverse to the second longitudinal axis (X2), the gas supply circuit (20) supplying gas to the ejection nozzles and comprising a first and a second gas conduit (27a, 27b) in fluid communication with them, the air supply circuit (31) supplying the first and second nozzles, the first and second ejection nozzles (41, 51) each comprising a internal portion in the first, respectively second, nozzle and an external portion protruding from these.Figure for the abridged version: 1.

Description

Title of the invention: Gas burner comprising a plurality of gas ejection nozzles technical field

[0001] The invention relates to the field of industrial-type gas burners, particularly for the production of terracotta building products (bricks, tiles). The invention also relates to industrial-type kilns incorporating such gas burners. Technological background

[0002] For example, tunnel-type gas-fired baking ovens are known, subdivided into several zones: a pre-oven, a preheating zone, a baking stage, and a cooling zone.

[0003] In an example of a tunnel furnace, a range of three different types of burners is installed: - high-power "jet" type burners (150kW-250kW), installed on the vertical walls of the oven in the preheating zone; - medium power "jet" type burners (80kW-100kW), installed on the oven vault, in places requiring a high concentration of power; - “Lance” type burners of reduced power (30kW-80kW), in areas where the atmosphere has a temperature above 750°C.

[0004] Jet-type burners are used at three power levels: "all (100%), little (idle) or none (off)", and operate by controlled ignition, while lance-type burners are used at two levels: "all or none", and operate by auto-ignition.

[0005] The design of existing gas burners restricts them to the exclusive use of natural gas and LPG. Furthermore, their mode of operation is relatively limited.

[0006] In brick and tile firing kilns, a large majority of the power used is distributed by "lance" type burners. Their design does not allow for optimization of the control method, and in particular does not allow for modulation of the heat output and / or the mixing.

[0007] The operator can adjust the lances in 3 ways: - by adjusting the amount of gas injected into the oven (gas pressure or diameter of the gas jets); - by adjusting the amount of air injected into the lance (gas with air in variable quantity or pure gas); - by choosing the flame shape by installing a coaxial ejection nozzle (straight axial jet), or a nozzle called "gas stove" (short radial jet).

[0008] Manual adjustments must be made individually on each burner for each significant change in product, range, or cooking rate (number of wagons of cooked products per given period). Burner shutdowns or nozzle changes are sometimes necessary when they are no longer suitable for new cooking processes.

[0009] Given the large number of burners installed in a tunnel furnace, this results in significant durations, downtimes and adjustment costs.

[0010] Furthermore, energy represents a significant portion of the manufacturing costs of terracotta building products. It is therefore also important to optimize the use of existing gas burners. Summary of the invention

[0011] One idea underlying the invention is to offer an economical and versatile gas burner and a cooking oven incorporating such a gas burner.

[0012] Another idea underlying the invention is to facilitate the adjustment of gas burners.

[0013] Another idea underlying the invention is to optimize the energy consumption of gas burners and reduce CO2 emissions related to the use of fossil fuels.

[0014] Another idea underlying the invention is to propose a gas burner that improves the homogeneity of cooking and the mixing of gases on the section of the cooking channel.

[0015] Another idea underlying the invention is also to reduce the length of the useful cooking step.

[0016] According to one embodiment, the invention provides a gas burner for industrial kilns, in particular kilns for firing terracotta products, comprising: - a cooking gas supply circuit, - an air supply circuit, - a first nozzle, the first nozzle extending along a first longitudinal axis, - a second nozzle, distinct from the first nozzle, the second nozzle extending along a second longitudinal axis, distinct from the first longitudinal axis, - a first ejection nozzle, connected to one end of the first nozzle and having a first through orifice at its distal end, said first through orifice being oriented parallel to the first longitudinal axis; and - a second ejection nozzle, connected to one end of the second nozzle and having at least one second through orifice oriented transversely to the second longitudinal axis, in which the cooking gas supply circuit is configured to supply cooking gas to the first ejection nozzle and the second ejection nozzle, the cooking gas supply circuit comprising a first gas conduit in fluid communication with the first ejection nozzle, and a second gas conduit in fluid communication with the second ejection nozzle, in which the air supply circuit is configured to supply air to the first nozzle and / or the second nozzle, in which the first ejection nozzle has an internal portion retained inside the first nozzle and an external portion protruding from the first nozzle, in which the second ejection nozzle has an internal portion retained inside the second nozzle and an external portion protruding from the second nozzle.

[0017] Thanks to these characteristics, the gas burner according to the invention makes it possible to offer at least two flame shapes in the same cooking cycle without having to manually adjust the ejection nozzle. These two flame shapes are: a first flame shape extending axially from the first ejection nozzle, and a second flame shape extending radially, that is, transversely to the general direction of extension of the first flame shape. Thus, with this type of burner, it is possible to easily alternate between flame shapes without requiring manual adjustment by the user. Furthermore, this type of burner also makes it possible to limit the number of burners in an oven and optimize their operating time. Alternating between flame shapes also allows the cooking process to be adapted to specific needs, particularly when using the same cooking method.This makes it possible to improve the mixing of gases, that is to say the mixing of cooking gas, air and hot gases resulting from combustion, in the oven and the homogeneity of the cooking over a section of the cooking oven.

[0018] This improved control of the cooking process offers further advantages. It allows, where necessary, for a reduction in the effective length of the cooking step. It also allows for a reduction in CO2 emissions related to the use of fossil fuels.

[0019] Moreover, advantageously, given its versatile structure, the gas burner according to the invention is well suited to sizing for different types of gas: natural gas, biogas, LPG, syngas, hydrogen, or a mixture of several of these gases.

[0020] According to embodiments, such a gas burner may include one or more of the following characteristics.

[0021] According to one embodiment, the second nozzle has a plurality of second through orifices. Optionally, these are regularly distributed around the periphery of the second nozzle.

[0022] Such a plurality of second through orifices allows the gas burner to ensure gas expulsion over a significant part of its perimeter and thus to offer good heat distribution and good thermal mixing in the oven in which the gas burner is installed.

[0023] Optionally, the second longitudinal axis is parallel to the first longitudinal axis.

[0024] Thus, the gas burner is of a most compact design.

[0025] According to one embodiment, the air supply circuit comprises a first air duct and a second air duct, the first air duct of the air supply circuit being in fluid communication with the first nozzle, and the second air duct of the air supply circuit being in fluid communication with the second nozzle.

[0026] Thus, the air supply circuit offers the possibility of varying the air flow selectively in the first nozzle and in the second nozzle according to the needs (flame shape, flame intensity, etc.).

[0027] According to one embodiment, the first gas conduit extends through the first nozzle, and the second gas conduit extends through the second nozzle.

[0028] Thus, the cooking gas supply circuit offers the possibility of varying the cooking gas flow selectively in the first nozzle and in the second nozzle according to the needs (flame shape, flame intensity, etc.).

[0029] According to one embodiment, at least one of the second ejection tip and the second nozzle comprises a first rotation restriction means allowing a determined angular positioning of the second ejection tip in the second nozzle.

[0030] Thus, the angular position of the second ejection nozzle and its at least one through orifice can be guaranteed, thereby ensuring control of the flame's orientation and, consequently, of the spatial distribution of the heat emitted by the flame. Such control contributes to limiting cooking defects and cooking waste.

[0031] According to one embodiment, the second ejection tip has substantially a flat outer face and an outer face in arc of a circle, corresponding in shape to a flat inner face and an inner face in arc of a circle that comprise the second nozzle, and in which the second ejection tip and the second nozzle are jointly configured to allow the second ejection tip to slide in the second nozzle.

[0032] Thus, the insertion of the second ejection nozzle during the assembly of the burner is facilitated in that the angular positioning of the second nozzle is guaranteed in a simple way, without the need for manual adjustment.

[0033] According to one embodiment, the second nozzle is aligned with the longitudinal axis of the second nozzle.

[0034] Thus, the sliding assembly of the second nozzle into the second nozzle is facilitated.

[0035] According to one embodiment, the gas burner comprises a common tube in which the first nozzle and the second nozzle extend, the outer walls of the first nozzle and the second nozzle preferably forming the outer walls of the common tube.

[0036] Thus, the very design of the gas burner allows the use of a single existing orifice through a cooking oven wall.

[0037] Advantageously, the common tube can be cylindrical in shape, preferably with a circular cross-section.

[0038] It is therefore possible to reuse identically the through-holes of gas burner installations in existing cooking ovens.

[0039] According to one embodiment, the first nozzle and the second nozzle are separated by a common wall, the common wall preferably being flat

[0040] Thus, the gas burner is particularly compact.

[0041] According to one embodiment, the common wall has at least one air passage orifice, the at least one air passage orifice being configured to achieve fluid communication between the first nozzle and the second nozzle.

[0042] Thus, a minimal air passage (leakage airflow) is permitted between the first nozzle and the second nozzle, and prevents cooking gas and / or a flame from flowing upstream into the unused of the two nozzles, thus protecting the body of the gas burner.

[0043] According to one embodiment, the position of a distal end of the first gas conduit is adjustable in a direction parallel to the first longitudinal axis with respect to the first ejection nozzle, preferably between a first position and a second position in which, in the first position, an end orifice of the distal end of the first gas conduit opens into the first ejection nozzle, and, in the second position, the end orifice of the first gas conduit is located upstream of the first ejection nozzle.

[0044] Thus, it is possible to vary the incidence of the airflow surrounding the flame and to play on its shape and temperature.

[0045] According to one embodiment, a first distance is defined between a center of the first through orifice and the distal end of the first nozzle in the direction of the first longitudinal axis, and a second distance is defined between a center of at least one second through orifice and the distal end of the first nozzle in the direction of the first longitudinal axis, the second distance being greater than the first distance

[0046] Thus, the second ejection nozzle expels the cooking gas radially beyond the first ejection nozzle, so that the first ejection nozzle does not obstruct the expulsion of gas opposite the second through orifice. This configuration therefore ensures the shape of the second flame.

[0047] According to one embodiment, the invention also provides a baking oven comprising at least one gas burner as described above, and at least one oven wall provided with a through-installation port, the oven wall delimiting a baking chamber, the gas burner being installed through the oven wall in the through-installation port, the first ejection nozzle and the second ejection nozzle being arranged protruding into the baking chamber.

[0048] Such a cooking oven benefits from the versatility of use of the aforementioned gas burner.

[0049] Advantageously, the baking oven comprises a plurality of gas burners and a plurality of installation through ports corresponding to the number of gas burners in the plurality of burners, each gas burner being installed in a corresponding through port.

[0050] The baking oven can advantageously be a tunnel oven.

[0051] The invention further relates to a method of using a gas burner as described above, in which the method comprises the following steps: - opening of the first gas duct to allow the circulation of a cooking gas flow in order to supply cooking gas to the first ejection nozzle and to generate a flame at the first through orifice, - closure of the first gas pipe, - opening of the second gas duct to allow the circulation of a cooking gas flow in order to supply cooking gas to the second ejection nozzle and to generate a flame at the second through orifice, - closure of the second gas pipe.

[0052] According to a particular embodiment, in the aforementioned method of using the gas burner, the opening and closing cycle of the first gas duct and the opening and closing cycle of the second gas duct can be implemented one after the other, one before the other, or even combined sequentially, each one or more times during the same cooking process.

[0053] The alternating use of these cycles contributes advantageously to the efficiency of the cooking process thanks to the alternating use of the first nozzle and the second nozzle.

[0054] According to a particular embodiment, in the method of using the gas burner, during the opening and closing cycle of the first gas conduit, the first nozzle is supplied alternately: - by a leakage airflow with an absolute pressure greater than the absolute pressure in the cooking chamber at the level of the gas burner, preferably a relative pressure less than or equal to 5 mbar, and preferably even greater than 0.1 mbar, and, - by a transport air flow of a relative pressure greater than or equal to 10 mbar, and preferably less than or equal to 0.5 bar.

[0055] Thus, the method of use allows an even more versatile use of the gas burner by allowing the production of at least two types of axially shaped flames, i.e. two cooking modes, with a transport airflow allowing the cooking gas to be conveyed or with only a leakage airflow allowing the cooking gas to be prevented from rising back into the air duct.

[0056] According to a particular embodiment, in the method of using the gas burner, the air supply circuit comprising a first air duct and a second air duct, the first air duct being in fluid communication with the first nozzle, and the second air duct being in fluid communication with the second nozzle, the first and second nozzles of the gas burner being separated by a common wall comprising at least one air passage orifice configured to achieve fluid communication between the first and second nozzles, During the opening and closing cycle of the first gas duct, the first nozzle is alternately supplied with air: - by the aforementioned leaky airflow, via the first air duct, and / or via both the second air duct and at least one air passage; or, - by the aforementioned transport airflow via the first air duct.

[0057] According to a particular embodiment, in the method of using the gas burner, during the opening and closing cycle of the first gas conduit, the cooking gas flow supplying the first ejection nozzle is alternately at a relative pressure greater than or equal to 1 bar, and at a relative pressure less than 1 bar, preferably less than 0.8 bar.

[0058] Thus, the method of use allows an even more versatile use of the gas burner by allowing the production of at least two types of axially shaped flames, i.e. two cooking modes, by acting on the relative pressure of the gas flow passing through the first gas conduit.

[0059] By playing, moreover, on both the air pressure and the gas pressure according to the aforementioned variants, at least four types of flame, that is to say four cooking modes, can be produced. Brief description of the figures

[0060] The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent from the following description of several particular embodiments of the invention, given solely by way of illustration and not limitation, with reference to the accompanying drawings.

[0061] Fig. 1 represents a schematic view of a cooking oven comprising a wall, and a gas burner mounted through the wall according to one embodiment;

[0062] [Fig.2] is an enlargement of one end of the gas burner of [Fig.1] mounted in a baking oven, showing in particular a first nozzle fitted with a first ejection tip, and a second nozzle fitted with a second ejection tip;

[0063] [Fig.3] is a cross-sectional view of the gas burner according to reference AA of [Fig.1];

[0064] [Fig.4] is an enlargement of a second ejection nozzle taken in isolation;

[0065] [Fig.5] is a cross-sectional view of the gas burner according to the BB reference mark of [Fig.2]. Description of the implementation methods

[0066] In this description, the terms "gas" and "cooking gas" are to be understood as referring to a gas with a high calorific value, or a mixture of gases having such a high calorific value, and different from air, unless otherwise specified.

[0067] Figure 1 shows an industrial firing kiln 1, for example, designed for firing terracotta products, not shown. The firing kiln 1 may advantageously be a tunnel-type gas-fired kiln subdivided into several zones: a pre-kiln, a preheating zone, a firing chamber, and a cooling zone. The firing kiln 1 has at least one wall 2, having at least one through-hole 3. The wall 2 delimits a firing chamber 10. The wall 2 may be, but is not limited to, a vault wall, i.e., a ceiling, or a side or vertical wall of the firing kiln 1. The wall 2 has, for example, a structural layer 201 and an insulating layer 202.The structural layer 201 serves as a support for the various elements of the baking oven 1, while the insulating layer 202 helps to maintain the heat in the baking chamber 10 while protecting the metallic parts of the baking oven 1, such as the nozzles 40 and 50 described below, from the baking heat.

[0068] The cooking oven 1 still includes at least one gas burner 5.

[0069] As shown in particular in [Fig. 2], the gas burner 5 is installed on the wall 2 through the through-hole 3, such that the distal ends 42 and 52 of a first and second ejection nozzle 41 and 51 of the gas burner 5 are positioned projecting into the cooking chamber 10. Preferably, but not exclusively, the distal end 42 of the first nozzle The ejection nozzle 41 protrudes at least 10 mm into the cooking chamber 10 relative to the insulating layer 202, see [Fig. 1]. To simplify the reading of [Fig. 2], the insulating layer 202 is not shown there.

[0070] The description below and the accompanying set of figures describe, by way of example, a baking oven 1 comprising an orifice 3 and a corresponding gas burner 5. However, the number of orifices and gas burners described is not limiting, and the baking oven 1 may also comprise a plurality of orifices 3 and a plurality of corresponding gas burners 5. By way of non-limiting examples, the baking oven 1 may comprise 60, 90, 120 gas burners 5, or any number appropriate to the use case, and as many corresponding orifices to accommodate them.

[0071] In the example illustrated in figures 1 and 2, the gas burner 5 is fixed to the wall 2 by a fixing member 60. The fixing member 60 comprises a tubular section 61, receiving a tube 7, as described below, of the gas burner 5, and a plate 62, disposed against an outer face 4 of the wall 2.

[0072] The gas burner 5 includes a cooking gas supply circuit 20 and an air supply circuit 31. The gas burner 5 further includes a first nozzle 40, a second nozzle 50, a first ejection nozzle 41, and a second ejection nozzle 51. The first nozzle 40 and the second nozzle 50 are preferably made of refractory metal. The first nozzle 41 and the second nozzle 51 are preferably made of ceramic.

[0073] The cooking gas supply circuit 20 here comprises: a first conduit 27a, a second conduit 27b, a main supply line 21, a high-pressure gas line 22, a low-pressure gas line 23 and a connecting line 24.

[0074] The main supply line 21 is provided with a filter 28. The main supply line 21 supplies cooking gas, on the one hand, to the high-pressure gas line 22 and the low-pressure gas line 23.

[0075] The high-pressure gas line 22 is connected in fluid communication to the first line 27a. The high-pressure gas line 22 has a solenoid valve 30a.

[0076] The low-pressure gas line 23 is connected in fluid communication to the second line 27b. The low-pressure gas line 23 here has a regulator 29, or pressure reducer, allowing the gas pressure to be lowered at its outlet, as well as a solenoid valve 30b.

[0077] The connecting pipe 24 also connects the outlet of the regulator 29 to the first pipe 27a via fluid communication. The connecting pipe has a solenoid valve 30c.

[0078] Thus, the solenoid valves 30a, 30b and 30c allow the selective supply of the first conduit 27a in high pressure gas, second conduit 27b in low pressure gas, and first conduit 27a in low pressure gas.

[0079] The air supply circuit 31 comprises a first air duct 33, a second air duct 34, and a main supply line 32. The main supply line 32 supplies air to the first air duct 33 and the second air duct 34. Each of the first air duct 33 and the second air duct 34 is here provided with an automated valve 35 and a manual valve 36 allowing the airflow through them to be regulated at will.

[0080] Each automated valve 35 is preferably a fast-acting valve. Each automated valve 35 may be, for example, but not limited to, a solenoid valve or a pneumatic valve.

[0081] The first air duct 33 is connected in fluid communication with the first nozzle 40. The second air duct 34 is connected in fluid communication with the second nozzle 50. The air supply circuit 31 is thus configured to supply air to the first nozzle 40 and the second nozzle 50.

[0082] Each of the automated valves 35 has at least one operating state, in which it allows a flow of transport air to pass through, and a leakage state, in which it allows a flow of leakage air to pass through. The transport airflow carries the cooking gas, that is, it gives the respective flame the desired shape. The leakage airflow prevents the cooking gas and / or the flame from flowing back upstream into the corresponding unused nozzle and air duct, thus protecting the gas burner 5.

[0083] As can be seen in Figures 1 and 2, the first nozzle 40 extends along a first longitudinal axis XL. The second nozzle 50 extends along a second longitudinal axis X2, distinct from the first longitudinal axis XI, in other words, not coaxial with the first longitudinal axis XL. More specifically, in the embodiment shown, the second longitudinal axis X2 is parallel to the longitudinal axis XL.

[0084] The first nozzle 40 and the second nozzle 50 extend into the aforementioned cylindrical tube 7, which thus forms a common tube. Preferably, as illustrated, the outer walls of the first nozzle 40 and the second nozzle 50 form the outer walls of the common tube 7. The first nozzle 40 and the second nozzle 50 are separated by a common wall 71, as illustrated in particular in Figures 3 and 5. Preferably, the common wall 71 is flat.

[0085] In a particular embodiment, illustrated in [Fig. 3], the common wall 71 has at least one air passage orifice 72, preferably a plurality of air passage orifices 72. The air passage orifice(s) 72 is / are configured to provide a fluid connection between the first nozzle 40 and the second nozzle 50. A minimal airflow (called leakage airflow) is thus permitted between the first nozzle 40 and the second nozzle 50, and prevents the cooking gas and / or flame from flowing upstream into the unused of the two nozzles, thus protecting the gas burner 5.

[0086] When the first gas conduit 27a is opened to the circulation of a cooking gas flow, the first nozzle 40 can thus be selectively supplied: - by the aforementioned leaky airflow; - by a transport airflow.

[0087] The first nozzle 40 is preferably, but not exclusively, supplied with air from the leakage stream via the first air duct 33. The automated valve 35 of the first air duct 34 is then open and in a leakage state. In an alternative configuration not shown, a bypass duct for the automated valve 35, also not shown, is provided. A manual or automatic valve can then be provided on the bypass duct to allow the leakage airflow to pass through at the desired pressure. The automated valve 35 of the first air duct 34 is then preferably in a closed state.

[0088] In another embodiment, the first nozzle 40 is supplied with the leakage airflow via both the second air duct 34 and at least one air passage 72, with the automated valve 35 of the second air duct 34 open. The automated valve 35 of the first air duct 33 is then preferably closed.

[0089] The supply of the first nozzle 40 by the transport airflow can be carried out via the first air duct 33, the automated valve 35 of the first air duct 33 being open.

[0090] The first ejection tip 41 is connected to one end of the first nozzle 40. The first ejection tip 41 has a first through orifice 43 at its distal end 42. Said first through orifice 43 is oriented parallel to the first longitudinal axis XL. With such a configuration, the first ejection tip 41 makes it possible to produce a flame with a general orientation along the first longitudinal axis XI, called for example a "longitudinal" or "axial" flame.

[0091] As illustrated in [Fig.2], an internal portion 410 of the first ejection tip 41 is configured to be retained inside the first nozzle 40. An external portion 411 of the first ejection tip 41 is configured to protrude from the first nozzle 40. For this purpose, a stop 412, here in the form of a lug, is formed at the junction between the internal 410 and external 411 portions of the first ejection tip 41. The stop 412 comes into contact with an end wall 440 of the first nozzle 40.

[0092] In variants not illustrated, the shape of the stop 412 is different. The stop may, for example, be in the form of a semi-circular ring, a plurality of fingers, etc.

[0093] The second ejection tip 51 is connected to one end of the second nozzle 50. The second ejection tip 51 has at least one second through-hole 53 at its distal end 52, oriented transversely to the second longitudinal axis X2. With such a configuration, the second ejection tip 51 produces a flame with a general orientation transverse to the second longitudinal axis X2, for example, a "radial" flame. In a variant not shown, the second ejection tip 51 may have a plurality of second through-holes 53: two, three, or more. The plurality of second through-holes 53 may then, but not limited to, be evenly distributed around the periphery of the second ejection tip 51.

[0094] As illustrated in Figures 2 and 4, an internal portion 510 of the second ejection tip 51 is configured to be retained inside the second nozzle 50. An external portion 511 of the second ejection tip 51 is configured to protrude from the second nozzle 50. For this purpose, a stop 512, here in the form of a lug, visible in [Fig. 4], is formed at the junction between the internal 510 and external 511 portions of the second ejection tip 51. In the illustrated example, the stop 512 comes into contact with an end wall 540 of the second nozzle 50, here common with the aforementioned end wall 440 of the first nozzle 40.

[0095] In variants not illustrated, the shape of the stop 512 is different. The stop 512 may, for example, be in the form of a semi-circular ring, a plurality of fingers, etc.

[0096] An external section of the second ejection tip 51 can be provided to correspond in shape with an internal section of the second nozzle 50. The external section of the second ejection tip 51 and the internal section of the second nozzle 50 can then be jointly configured to limit, preferably prevent, a rotation of the second ejection tip 51 about its own longitudinal axis.

[0097] For this purpose, at least one of the second ejection tip 51 and the second nozzle 50 comprises a first rotation restriction means 55, 65 allowing a determined angular positioning of the second ejection tip 51 in the second nozzle 50.

[0098] In the illustrated embodiment, the second ejection nozzle 51 substantially has a flat outer face 55 and a circular arc outer face 56, see Figures 4 and 5. The flat outer face 55 and the circular arc outer face 56 correspond in shape to a flat inner face 65 and a circular arc inner face 66 of the second nozzle 50. The second ejection nozzle 51 and the second nozzle 50 are jointly configured to allow the second ejection nozzle 51 to slide within the second nozzle 50.

[0099] Optionally, by analogy with the second ejection nozzle 51 and as illustrated in [Fig. 5], the first ejection nozzle 41 here substantially has a flat outer face 45 and an outer face in the shape of an arc 46. The flat outer face 45 and the outer face in the shape of an arc 46 then correspond in form with a flat inner face and an inner face in the shape of an arc in the first nozzle 40. The first ejection nozzle 41 and the first nozzle 40 are then jointly configured to allow the first ejection nozzle 41 to slide within the first nozzle 40.

[0100] With the configuration described above, the cooking gas supply circuit 20 is configured to supply cooking gas to the first ejection nozzle 41 and the second ejection nozzle 51. For this purpose, the aforementioned first gas conduit 27a is connected in fluid communication with the first ejection nozzle 4L. The second gas conduit 27b is connected in fluid communication with the second ejection nozzle 51.

[0101] Structurally, the first gas conduit 27a is arranged to extend through the first nozzle 40, as shown in [Fig. 3]. The second gas conduit 27b is arranged to extend through the second nozzle 50.

[0102] In the embodiment illustrated in Figures 1 and 2, the position of a distal end 48, referenced in [Fig. 2], of the first gas conduit 27a is adjustable parallel to the first longitudinal axis XI relative to the first ejection nozzle 4L. Preferably, this adjustment is possible between a first position J and a second position K in which: - in the first position J, an end orifice 47a of the distal end 48 of the first gas conduit 27a opens into the first ejection nozzle 41, and - in the second position K, the end orifice 47a of the first gas conduit 27a is located upstream of the first ejection nozzle 4L

[0103] Positions J and K are illustrated by way of non-limiting example in [Fig.2].

[0104] Here, an end orifice 47b of the second gas conduit 27b opens from preferably, but not exclusively, in the second ejection nozzle 51.

[0105] Furthermore, as illustrated in [Fig. 2], a first distance H1 is defined between a center of the first orifice through 43 and the distal end 44 of the first nozzle 40 in the direction of the first longitudinal axis XL. A second distance H2 is defined between a center of at least one second orifice through 53 and the distal end 44 of the first nozzle 40 in the direction of the first longitudinal axis XL. The second distance H2 is greater than the first distance H1

[0106] The cooking oven 1 and its gas burner 5 as described above can be used to enable, during the same cooking process:

[0107] - an opening in the first gas conduit 27a to the circulation of a gas flow cooking in such a way as to supply cooking gas to the first ejection nozzle 41 and to generate a flame at the first through orifice 43, - a closure of the first gas conduit 27a, - an opening of the second gas conduit 27b to the circulation of a flow of cooking gas so as to supply cooking gas to the second ejection nozzle 51 and to generate a flame at the level of the second through orifice 53, - a closing of the second gas conduit 27b.

[0108] The opening and closing cycle of the first gas duct 27a and the opening and closing cycle of the second gas duct 27b can be implemented one after the other, one before the other, or each combined once or several times during the same cooking process.

[0109] The first form of flame can be the aforementioned axial flame, while the second form of flame can be the radial flame.

[0110] In order to implement the baking oven 1 and / or the gas burner 5 described above, the baking oven 1 and / or the gas burner 5 may include a programmable logic controller (PLC) 6, see [Fig. 1]. Here, for the sake of clarity, the PLC 6 is shown as being connected exclusively to the solenoid valve 30b. It should be understood that the PLC 6 may also be connected to the solenoid valves 30a and 30c, as well as to the controller 29 and the automated valves 35.

[0111] The programmable logic controller 6 can advantageously be configured to operate by pulses. In such pulse operation, the opening / closing cycles of the solenoid valves 30a, 30b, and 30c and the automated valves 35 can be very rapid. The pulses, i.e., the time during which a solenoid valve 30a, 30b, or 30c, or an automated valve 35, remains open, can be set to last from 1 millisecond to a few seconds, for example, 10, 7, or 5 seconds. Such pulse operation makes it possible to sequence the use of the solenoid valves 30a, 30b, and 30c and the automated valves 35, which allows the gas burner 5 to improve the mixing in the baking oven 1.

[0112] Although the invention has been described in connection with several particular embodiments, it is clearly evident that it is by no means limited to them and that it includes all technical equivalents of the means described as well as their combinations if these fall within the scope of the invention.

[0113] The use of the verb "comprise", "comprendre" or "include" and its conjugated forms does not exclude the presence of other elements or steps than those stated in a claim.

[0114] In the claims, any reference sign in parentheses shall not be interpreted as a limitation of the claim.

Claims

Demands

1. Gas burner intended for industrial kilns (1), in particular kilns for firing terracotta products, comprising: - a firing gas supply circuit (20), - an air supply circuit (31), - a first nozzle (40), the first nozzle (40) extending along a first longitudinal axis (XI), - a second nozzle (50), distinct from the first nozzle (40), the second nozzle (50) extending along a second longitudinal axis (X2), distinct from the first longitudinal axis (XI), - a first ejection tip (41), connected to one end of the first nozzle (40) and having a first through orifice (43) at its distal end (42), said first through orifice (43) being oriented parallel to the first longitudinal axis (XI); and - a second ejection nozzle (51), connected to one end of the second nozzle (50) and having at least one second through orifice (53) oriented transversely to the second longitudinal axis (X2),wherein the cooking gas supply circuit (20) is configured to supply cooking gas to the first ejection nozzle (41) and the second ejection nozzle (51), the cooking gas supply circuit (20) comprising a first gas conduit (27a) in fluid communication with the first ejection nozzle (41), and a second gas conduit (27b) in fluid communication with the second ejection nozzle (51), wherein the air supply circuit (31) is configured to supply air to the first nozzle (40) and / or the second nozzle (50), wherein the first ejection nozzle (41) has an internal portion retained inside the first nozzle (40) and an external portion projecting from the first nozzle (40), wherein the second ejection nozzle (51) has an internal portion retained inside the second nozzle (50) and an external portion protruding from the second nozzle (50).

2. A gas burner according to claim 1, wherein the air supply circuit (31) comprises a first air duct (33) and a second air duct (34), the first air duct of the air supply circuit (31) being in fluid communication with the first nozzle (40), and the second air duct of the air supply circuit (31) being in fluid communication with the second nozzle (50).

3. Gas burner according to claim 1 or claim 2, wherein the first gas conduit (27a) extends through the first nozzle (40), and the second gas conduit (27b) extends through the second nozzle (50).

4. Gas burner according to any one of the preceding claims, wherein at least one of the second ejection tip (51) and the second nozzle (50) comprises a first rotation restriction means (55, 65) allowing a determined angular positioning of the second ejection tip (51) in the second nozzle (50).

5. Gas burner according to the preceding claim, wherein the second ejection tip (51) has substantially a flat outer face (55) and an arcuate outer face (56), corresponding in form to a flat inner face (65) and an arcuate inner face (66) which comprise the second nozzle (50), and wherein the second ejection tip (51) and the second nozzle (50) are jointly configured to allow the second ejection tip (51) to slide into the second nozzle (50).

6. Gas burner according to any one of the preceding claims, in which the gas burner comprises a common tube (7) in which the first nozzle (40) and the second nozzle (50) extend, the outer walls of the first nozzle (40) and the second nozzle (50) preferably forming the outer walls of the common tube (7).

7. Gas burner according to any one of the preceding claims, wherein the first nozzle (40) and the second nozzle (50) are separated by a common wall (71), the common wall (71) preferably being flat.

8. Gas burner according to any one of the preceding claims, wherein the position of a distal end (48) of the first gas conduit (27a) is adjustable in a direction parallel to the first longitudinal axis (XI) with respect to the first ejection nozzle (41), preferably between a first position (J) and a second position (K) wherein, in the first position (J), an end orifice (47a) of the distal end (48) of the first gas conduit (27a) opens into the first ejection nozzle (41), and, in the second position (K), the end orifice (47a) of the first gas conduit (27a) is located upstream of the first ejection nozzle (41).

9. Gas burner according to any one of the preceding claims, wherein a first distance (H1) is defined between a center of the first through orifice (43) and the distal end (44) of the first nozzle (40) in the direction of the first longitudinal axis (XI), and a second distance (H2) is defined between a center of at least one second through orifice (53) and the distal end (44) of the first nozzle (40) in the direction of the first longitudinal axis (XI), the second distance (H2) being greater than the first distance (H1).

10. Baking oven (1) comprising at least one gas burner (5) according to any one of the preceding claims, and at least one oven wall (2) having a through-installation port (3), the oven wall (2) delimiting a baking chamber (10), the gas burner (5) being installed through the oven wall (2) in the through-installation port (3), the first ejection nozzle (41) and the second ejection nozzle (51) being arranged projecting into the baking chamber (10).

11. A method of using a gas burner (5) according to any one of claims 1 to 9, wherein the method comprises the following steps: - opening the first gas conduit (27a) to the circulation of a cooking gas stream so as to supply cooking gas to the first ejection nozzle (41) and to generate a flame at the first through orifice (43), - closing the first gas conduit (27a), - opening the second gas conduit (27b) to the circulation of a cooking gas stream so as to supply cooking gas to the second ejection nozzle (51) and to generate a flame at the second through orifice (53), - closing the second gas conduit (27b).

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