Patent ID: 12222103

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

FIG.1shows a burner1according to one form of the present disclosure. The burner1is intended to equip a furnace, in particular a food furnace. The burner1longitudinally extends along an axis A, in one optional form extends over a length of at least 4 meters, and may be for example between 4 and 8 meters. The burner1is therefore a large burner1.

The burner1includes a combustion tube2formed of several tubular modules20, a distribution tube4arranged inside the combustion tube2, and a porous support6supported by the combustion tube2and on the surface of which is intended to burn a pre-mixture of air and gas. The burner1is advantageously a burner1with premixing and surface combustion.

The porous support6is a fuel permeable support, for example a premix of gas and air. The porous support6advantageously includes metallic fibers, which can be woven so that the porous support6forms a flexible metallic fabric. These metal fibers are made of a fire-resistant alloy configured to resist corrosion at temperatures above 1000° C., such as, for example, Fecralloy®.

The porous support6selectively allows using a heat transfer mode by radiation (infrared) or by convection (blue flame), and offers an easy transition between these two modes. By radiation heat transfer mode (infrared) is meant a thermal transfer with a power density in the range of 100 to 500 kW·m−2. By a thermal transfer mode by convection (blue flame) is meant a thermal transfer with a power density in the range of 500 to 10,000 kW·m−2.

The combustion tube2extends longitudinally along the axis A and supports the porous support6. The porous support6can be fixed on the combustion tube2by spot welding (fusion of the fabric forming the porous support6with the combustion tube2). The porous support6therefore also extends longitudinally along the axis A, in particular, over the entire length of the combustion tube2.

The combustion tube2is hollow, advantageously cylindrical. The combustion tube2has an upstream end, connected and closed by a supply module8, and a downstream end, connected and closed by a closure module10.

The combustion tube2is perforated. As represented inFIG.2, the combustion tube2has, along its lateral wall, a plurality of combustion openings22, passing through and arranged under the porous support6to allow fuel to flow from the inside of the combustion tube2to the porous support6where combustion takes place. These openings22can be arranged longitudinally at regular intervals from one another. They may have the form of slots, in particular slots orthogonal to the longitudinal axis A. They are for example aligned along the axis A, as illustrated inFIG.2.

The combustion tube2includes a plurality of tubular modules20aligned and connected one after the other so as to form the combustion tube2. Each tubular module20therefore constitutes a section of the combustion tube. Thus, as visible inFIG.3, each tubular module20supports part of the porous support6. Furthermore, each tubular module20includes through openings, like those illustrated inFIG.2, allowing the fuel to pass from the inside of the tubular module20to the porous support6.

The tubular modules20are advantageously similar. In particular, they can be of equal length. According to the example ofFIG.1, the combustion tube2includes eight tubular modules20. It could include less or more tubular modules20. Thus, according to the example ofFIG.10, which will be described in more detail below, the combustion tube2includes for example nine tubular modules20.

The tubular modules20are fixed end to end to each other to form the combustion tube. To this end, as can be seen inFIG.3, the burner1includes fixing means making it possible to fix the adjacent tubular modules20in a rigid and sealed manner. The fixing means can include, in particular, fixing flanges24, intended to be pressed in pairs, these flanges24can be kept tight against one another by screw-nut type tightening means.

The fixing flanges24can be arranged at the ends of the tubular modules20. Thus, each tubular module20includes a first fixing flange24, at an upstream end20aof the tubular module20, and a second fixing flange24, at a downstream end. The first flange24of fixing a tubular module20is intended to be fixed to the second flange24of fixing a previous tubular module20.

The flanges24, possibly in the form of a plate, have a collar projecting radially from the lateral wall of the tubular modules20and therefore from the combustion tube. The flanges24are for example orthogonal to the longitudinal axis A. The fixing flanges24have an advantageously flat fixing face240, intended to receive the fixing face of another fixing flange24.

In one optional form, the fixing flanges24do not extend all around the combustion tube. They can have a primary notch242allowing passage of the porous support6at the junction of two adjacent tubular modules20. As illustrated inFIG.4(where the porous support6is not represented), the fixing flanges24may include one or more secondary notches244at the bottom of the primary notch242, in order to allow an escape of gas in the direction of the porous support6at the junction of the tubular modules20. This or these secondary notches244form calibrated leakage means, between the tubular module20and the porous support6, on the one hand, and between the two adjacent tubular modules20, on the other hand. The calibrated leakage means are located under the porous support6, to ensure the continuity of the flame at the junction of two tubular modules20.

Advantageously, the fixing flanges24do not only extend outside the combustion tube2by forming a collar, but also inside the combustion tube2, forming a partition wall246preventing the passage of the fuel located in the combustion tube2from one tubular module20to the other (except via the calibrated leakage means), as illustrated inFIG.3. This partitioning allows a more homogeneous distribution of the fuel along the burner1. The partition wall246extends annularly around the distribution tube(s)4responsible for distributing the fuel in the tubular modules20.

The fixing flanges24may have one or more axial through openings248allowing the passage of a distribution tube4. In one optional form, each through opening248has a shape complementary to that of the distribution tube4that it receives. The through opening(s)248extend through the partition wall246to allow the distribution tube(s) to pass through the junction of two adjacent tubular modules20. According to the example ofFIG.3, the fixing flanges24comprise a single central through opening248, allowing the passage of the single distribution tube4. According to the example ofFIGS.10to18, the fixing flanges24comprise one, two or three through openings248each allowing the passage of a distinct distribution tube4.

The fixing flanges24thus close the ends of the tubular modules20, except to achieve the calibrated leakage or to allow the passage of the distribution tube(s)4from one module20to another. The fixing flanges24also make it possible to support the distribution tube(s)4which extend inside the combustion tube2. This or these distribution tubes4in fact rest on the inner edge delimiting the corresponding through opening248.

The distribution tube(s)4are intended to distribute the fuel in a predetermined manner within the combustion tube2. Each distribution tube4extends inside the combustion tube, along the longitudinal axis A, and includes (see for exampleFIG.18) an orifice40allowing fuel inlet. This inlet orifice40can extend inside a supply module8of the burner1.

Unlike the combustion tube2, the distribution tube(s)4are advantageously not designed in a modular fashion and can extend in a single piece from their upstream end where the inlet orifice is located up to their downstream end. The distribution tube(s)4have a smaller diameter than the combustion tube2to allow the fuel to circulate about the distribution tube(s)4, that is to say in the combustion tube2, once the fuel has left the distribution tube4.

As described above, each distribution tube4can be supported and held in place inside the combustion tube2by means of the fixing flanges24.

Each distribution tube4includes a distribution portion42, including one or more distribution orifices420(seeFIGS.14,15) through a lateral wall of the distribution tube4, to allow the passage of fuel from the inside of the distribution tube4into the combustion tube2. The distribution orifices420can be in the form of slots, advantageously orthogonal to the longitudinal axis A of the burner1. They can be arranged in staggered rows.

With reference toFIG.6, the burner1includes a single distribution tube4and therefore a single combustion zone. This single distribution tube4, more precisely its distribution portion42, extends through all the tubular modules20of the combustion tube2in order to distribute the fuel in each of these tubular modules20, all along the burner1. As visible inFIG.6, the distribution orifices420are in this example arranged diametrically opposed to the porous support6in order to homogeneously distribute within the combustion tube. Moreover, these distribution orifices420can be distributed at regular intervals along the axis A, and for example aligned.

With reference toFIG.10, and toFIGS.11to18, the burner1can alternatively include several distribution tubes4making it possible to create several combustion zones A, B, C which can be controlled independently of one another. Where appropriate, each distribution tube4is intended to distribute the fuel in a predetermined combustion zone of the combustion tube2.

In particular, these distribution tubes4include a primary distribution4, which is intended to distribute the fuel in the combustion zone A most upstream of the combustion tube2, and one or more (e.g., two according to the example ofFIGS.10to13) secondary distribution tubes4intended to distribute the fuel in combustion zones B, C located downstream.

For example, as illustrated inFIGS.10to13, the combustion tube2includes three combustion zones A, B, C, and consequently three distribution tubes4for distributing the fuel in each of the three combustion zones A, B, C. Each combustion zone can be formed by the same number of tubular modules20, for example three (e.g., the combustion tube2here including nine tubular modules20).FIG.11shows the first combustion zone,FIG.12the second combustion zone,FIG.13the last combustion zone.

The primary and secondary distribution tubes4each include a distribution portion42having distribution orifices420intended to allow the passage of the fuel from the inside of the primary or secondary distribution tube4, into the corresponding zone of the combustion tube2. In one optional form, these distribution orifices420are arranged facing the porous support6. In one optional form, the distribution portion42extends from the first to the penultimate of the tubular modules20forming the concerned combustion zone.

Referring toFIGS.14and15, it will be noted that the distribution portion42advantageously has an upstream portion42ahaving, at equal length of the section, a larger perforation zone than a downstream portion42b. In particular, the upstream portion42aincludes more distribution orifices420than a section of the same length of the downstream portion42band/or distribution orifices420distributed over a wider angle than for the downstream portion42b. In one optional form, the distribution orifices420of the upstream portion42aare arranged all around, i.e., at 360°, about the axis A. The downstream portion42bhas distribution orifices420distributed over an angular range, for example comprised between 100° and 140°, in one optional form being between 110° and 130°, for example 119°, about the axis A.

Referring toFIGS.16and17, the distribution portion42of the primary and secondary distribution tubes4advantageously includes an end portion44which is axially closed by a deflector plug440making it possible to slow the arrival of fuel at the end of the combustion zone, as illustrated inFIG.17. In addition, as visible inFIG.16, the end part44includes a radial outlet opening442making it possible to release the rest of the fuel inside the last tubular module20from the corresponding combustion zone. Unlike the distribution orifices420of the distribution portion42, this radial outlet opening442is advantageously arranged diametrically opposed to the porous support6.

The end portion44extends into the last of the tubular modules20forming the combustion zone served by the corresponding distribution tube4. In one optional form, this terminal part44is arranged at the level of the upstream end20aof this tubular module20, or in any case at a distance from the downstream end20b, advantageously closer to the upstream end20athan to the downstream end20b. The end portion44extends over a length substantially shorter than that of the distribution portion42. For example, the length of the distribution tube4in the last tubular module20of the served combustion zone is less than a fifth, and in one optional form is less than a tenth of the length of this tubular module20.

The secondary distribution tubes4further include a blind portion46which is located upstream of their distribution portion42. This blind portion46, in the form of a tube without perforations on its lateral wall, is intended to extend through the combustion zone(s) located upstream of that served by the distribution portion42of the same distribution tube4.

Referring toFIG.11, the first combustion zone A is formed by the first three tubular modules20.1,20.2,20.3of the combustion tube2, and the primary distribution tube4A extends through these first three tubular modules20.1,20.2,20.3. In particular, the distribution portion42of the primary combustion tube2extends through the first and the second tubular module20.1,20.2. At the start of the combustion zone A, i.e., at the level of the upstream end of the first tubular module20.1, the distribution portion42has an upstream portion42ahaving a larger perforation zone than a downstream portion, for example at 360°. In the remainder of the first tubular module20.1, as well as in the second tubular module20.2, the distribution portion42has perforations arranged opposite the porous support6, with a perforation zone smaller than the upstream portion42a, for example at 119°. Finally, in the third and last tubular module20.3forming this first combustion zone A, the primary distribution tube4includes an end part44having the deflector plug440and a radial outlet opening442. This end part44extends near the upstream end20aof the last of the tubular modules20.3forming the first combustion zone A, over approximately one tenth of the length of this last tubular module20.3.

With reference toFIG.12, the second combustion zone B is formed by the following three tubular modules20.4,20.5,20.6(fourth, fifth and sixth modules) of the combustion tube. The secondary distribution tube4, which serves the third combustion zone C, has its blind part46extending through the modules20.4,20.5,20.6, so that it does not distribute fuel in this second combustion zone B. The distribution portion42of the secondary distribution tube4serving the second combustion zone B extends through the fourth and the fifth tubular modules20.4,20.5. At the start of the second combustion zone B, i.e., at the level of the upstream end of the fourth tubular module20.4, the distribution portion42has an upstream portion42ahaving a larger perforation zone, for example at 360°, than the downstream portion42b. In the remainder of the fourth tubular module20.4, as well as in the fifth tubular module20.5, the distribution portion42has distribution orifices420arranged facing the porous support6, with a perforation zone smaller than the upstream portion42a, for example at 119°. Finally, in the sixth and last tubular module20.6forming this second combustion zone B, the secondary distribution tube4serving this second combustion zone B includes an end portion44having a deflector plug440and a radial outlet opening442. This end portion44extends near the upstream end of the last of the tubular modules20.6, over approximately one tenth of the length of the latter tubular module20.6.

With reference toFIG.13, the third combustion zone C is formed by the following three tubular modules20.7,20.8,20.9(seventh, eighth and ninth modules) of the combustion tube. The distribution portion42of the secondary distribution tube4serving this third combustion zone C extends through the seventh and the eighth tubular modules20.7,20.8. At the start of the third combustion zone C, i.e., at the level of the upstream end of the seventh tubular module20.7, the distribution portion42has an upstream portion42ahaving a larger perforation zone, for example at 360°, than a downstream portion42b. In the remainder of the seventh tubular module20.7, as well as in the eighth tubular module20.8, the distribution portion42has distribution orifices420arranged opposite the porous support6, with a perforation zone smaller than the upstream portion42a, for example at 119°. Finally, in the ninth and last tubular module20.9forming this third combustion zone C, the distribution tube4includes an end part44having a deflector plug440and a radial outlet opening442. This end part44extends near the upstream end of the last of the tubular modules20.9, over approximately one tenth of the length of this last tubular module20.9.

As indicated previously, the burner1includes a supply module8connected upstream of the combustion tube2to supply each distribution tube4with fuel. The supply module8, as well as the closure module10where appropriate, can be connected to the first, respectively to the last, of the tubular modules20forming the combustion tube2by means of the fixing means described above, like the fixing brackets24. The supply module8allows the fuel supply of the distribution tube(s)4.

The burner1advantageously includes means for adjusting the flow rate of fuel entering the distribution tube4, or into each distribution tube4. When there are several distribution tubes4, the adjustment means allow the fuel flow rate to be adjusted for each distribution tube4independently of each other. As illustrated inFIG.18, the adjusting means can comprise, for each distribution tube4, an adjustment screw80.

With reference toFIGS.8and9, the supply module8includes sparking means, such as for example electrodes82visible inFIG.8, making it possible to start the combustion, and an end portion connected to the first tubular module20, this terminal portion84including one or more sparking orifices840passing through a lateral wall of the supply module8under the sparking means in order to allow fuel to pass to the sparking means. The porous support6extends between the sparking means and the sparking orifice(s)840. At equal length of section, the perforation zone of this end portion84is advantageously larger than that of the downstream combustion tube2. The sparking orifices840can be in the form of slots, advantageously orthogonal to the longitudinal axis A of the burner1. These sparking orifices can be arranged in staggered rows.

The disclosure also concerns a furnace the burner1such as previously described. In particular, this furnace can be a food furnace intended for cooking foods.

The disclosure is in no way limited to the specific forms described above, these forms have been given only by way of example. Those of skill in the art will appreciate that modifications to the examples can be done, in particular from the point of view of the constitution of the various devices or by the substitution of technical equivalents, without thereby departing from the scope of protection of the disclosure.

Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.