FR2926350A1 - METHOD AND FUSION OVEN. - Google Patents

Abstract

Process for melting a filler in an oven, the furnace being equipped in the upstream part of its melting zone with one or more lateral oxy-burners with an adjustable flame.

Description

The present invention relates to a method for melting a filler in an oven and a melting furnace for carrying out said process.

The invention more particularly relates to a method for melting a filler in an oven in which: the filler is introduced in solid form into the charging zone situated in the upstream part of the furnace, said filler in solid form is fed from the charging zone to the melting zone where it is heated and melted via at least one burner and the melted filler from the melting zone is fed to the sampling zone situated in the melting zone. downstream part of the oven where the load is taken from the oven.

Such furnaces, and especially such glass furnaces, are on the one hand very large energy consumers and on the other hand require significant investments. Their operation can only be profitable if their energy efficiency and productivity are competitive.

Regarding energy efficiency, glass furnaces are commonly equipped with combustion systems using as oxidizer or oxidant either air preheated through a regenerator or a recuperator, or essentially pure oxygen. In the first case, the energy efficiency is increased by increasing the temperature of the oxidant by recovering thermal energy from the fumes. In the second case, we mainly benefit from the reduction of the volume (mass flow) of the fumes to increase the combustion efficiency.

Glass furnaces are designed for a given output or productivity (derived or nominal productivity). When the pull or productivity of an existing glass kiln needs to be increased beyond the nominal output or productivity, the heating power must be increased. Similarly, when, due to technical problems, the actual productivity of a glass furnace falls below the nominal productivity, it can be envisaged to increase this productivity by an increment of the heating power. Nevertheless, the increase in the heating power of the oven is limited by restrictions imposed by the resistance, including thermal, limited refractory materials used in the oven.

It is thus known, in particular EP-A-0850884 to install in the charging zone two burners located on either side of the charging opening. It is in particular known from EP-A-0850884 to implant in an air-fuel burner glass furnace at least one additional oxy-fuel burner in a region upstream of the zone of the air-fuel burner furthest upstream. This technology is known under the name of oxyboosting in zero port. Thanks to this implantation, the cold points of the vault located on the first meters of it in the longitudinal direction of the oven considered from upstream to downstream, are reduced or even eliminated. As a result, the longevity of the vault is increased as a result of the suppression of the alkali condensation, and the adverse consequences of the flights are minimized. In addition, the energy is better distributed on the surface of the load (the specific heating surface is increased), and the quality is improved while the productivity of the oven is increased.

In the present context, the terms downstream and upstream are used relative to the path followed by the load from its charging in the oven. It is also known, in particular from EP-A-1077201, to increase the productivity of a glass furnace by the implantation of at least one oxy-fuel burner in the vault of the furnace, and this above the shaped glass filler. solid. The latter option has a number of disadvantages. Indeed, the glass furnaces are normally not designed to allow the installation of one or more vaulted burners and important work, long and expensive are therefore necessary: first the layer of thermal insulation on the vault must be removed, a layer of refractory concrete must then be placed on the vault, the insulation layer must be reconstructed over the concrete layer, a mounting platform must be installed above the layer of insulation, openings are created in the vault and the burners are finally mounted on the platform and through the openings. In addition, the presence of arch burners can weaken the latter and reduce their service life without maintenance.

Another disadvantage of vaulted burners is that their flames cover only a very limited surface area of the material to be heated and that a higher number of burners is therefore required per unit area compared to wall mounted burners. , which increases the complexity of the installation, the risks and the costs. Finally, the operating field of said burners is greatly limited because the positioning in the vault and perpendicular to the load to be heated imposes significant restrictions with respect to the length and speed of the flame to ensure sufficient heat transfer to the charge and avoid hot spots on the vault, which leads to limited flexibility of the technology.

The object of the present invention is to improve melting processes in furnaces of the type described above comprising at least one oxy-burner in the upstream part of the furnace.

In the following description of the invention, reference is made to the various non-limiting examples of implementation of the invention illustrated in FIGS. 1 to 5, in which: FIGS. 1 and 2 are diagrammatic representations of FIG. a glass furnace according to the invention in which only the burners in the upstream part of the furnace are represented; • Figure 3 is a schematic representation of a cross section of the upstream portion of a furnace according to the invention at a lateral oxybrûleur orientable flame; FIGS. 4a, b and c represent a schematic diagram of the variation of the orientation of the flame of an oxy-burner by means of fluid actuators; • Figure 5 is a schematic representation of a cross section of the upstream portion of a furnace according to the invention at a pair of orientable flame oxybrulers lateral.

The invention particularly relates to a method for melting a filler in an oven, said furnace having an upstream portion 11 in which the filler is at least partially present in solid form 31 and a downstream portion 12 in which the filler is fully present in molten form. The line 13 which distinguishes the part 11 of the furnace in which the feed is at least partially present in solid form (upstream part) of the part 12 in which the feed is entirely present in molten form (downstream part) is generally called the feed line. batch.

According to this method, the feed is introduced into the furnace in solid form in a charging zone 14 located in the upstream portion 11 of the furnace. The charge is then fed in solid form from the charging zone to a melting zone equipped with burners. This melting zone 15 is located partially in the upstream portion 11 and partially in the downstream portion 12 of the furnace. (In Figures 1 and 2, only the melting zone burners 15 in the upstream portion 11 of the furnace are shown.The melting zone burners 15 located in the downstream part 12 of the furnace are not shown.) In the melting zone the charge is heated and melted, in particular by energy transfer by means of said burners. The charge in molten form from the melting zone 15 is fed to a sampling zone 16 where it is taken from the furnace. This sampling zone 16 is located in the downstream part of the furnace 12.

According to the invention, the melting zone 15 is equipped in the upstream portion 11 of the furnace with at least one, preferably at least two, more preferably at least three and more preferably at least three four oxyburners 17, 17 'lateral directional flame, that is to say oxybrulers flame of variable orientation mounted in the side walls 18 of the furnace. For certain applications, in particular oxyboosting at zero port, use will be made of two orientable flame side oxy-burners 17, 17 ', typically in the form of a pair of oxy-burners as defined hereinafter. Oxygen burner means a burner whose gas associated with the fuel is significantly richer in oxygen than air, for example a gas comprising at least 40% and preferably at least 50% oxygen, for example a mixture of air and oxygen. The advantages of the process according to the invention are numerous. The use of a lateral oxy burner with adjustable flame makes it possible to vary the orientation of the flame without interrupting the operation of the burner. When the steerable oxy-burner is operated so that its flame sweeps the surface of the load, a larger area of the load can be covered by a single burner. From the oven can be increased by installing a limited number of oxy-burners in the upstream part of the oven. Moreover, this way of operating a steerable flame side oxy-burner greatly limits the risk of hot spots (superheated spots) on the charge in the melting zone (limiting the heat transfer to the charge), on the walls. side 18 and / or on the roof 30 of the oven. Due to the mounting of the oxy-burner 17 with a directional flame in a side wall of the furnace, the risk of raising the flame to the vault is reduced and the burner can be operated in a wider range of powers. No modification or adaptation of the oven vault is required, as is the case for vaulted burners.

The process according to the invention also makes it possible to correct asymmetries in the melting of the filler, dissymmetries which can, among other things, manifest themselves in the form of an asymmetry of the batch line.

An important advantage of the invention is that it makes it possible to increase the energy supplied in the upstream part of the furnace, for example in the case of oxyboosting, without the risk of overheating the vault.5 FIG. mounting a steerable side oxy-burner in a side wall 17 of the furnace, the flame 32 of said oxy-burner being oriented to impact the surface of the load 31, 33.

Advantageously, the first burner (s) encountered by the filler during its entry into the melting zone 15 are one or lateral oxyburners 17 orientable flame. Thus, according to the invention, the oxy-burner (s) 17 with an orientable flame are preferably situated directly downstream of the charging zone (14).

The furnace generally also comprises a refining zone downstream of the melting zone 15 and upstream of the sampling zone 16. In this case, the melted filler from the melting zone 15 passes through the refining zone where it is brought to the desired temperature and viscosity before entering the sampling zone 16.

After being taken from the furnace, the molten charge is typically fed into a feed channel of a forming machine. The feed channel brings the molten charge to the forming machine for shaping.

FIGS. 1 and 2 show two furnaces according to the invention comprising four lateral oxy-burners 17 with an orientable flame positioned directly downstream of the charging zone 14.

Preferably, the orientation of the flame of the directional flame or oxybrulers is changed or regulated by non-mechanical actuators. Indeed, the use of mechanical actuators, such as pivots, is unsustainable in a hostile environment, such as a glass melting furnace, since the mechanical actuators undergo particularly high temperatures, chemical attacks and mechanical and pollutant deposits present in the furnace atmosphere.

Thus, the variation of the orientation of the flame is preferably provided by fluidic interactions between several jets of fluid. In this case, the orientation of the flame is modified or adjusted by means of one or more jets of secondary fluid (s), typically secondary gas jets, called fluid actuators.

For example, according to the invention, said at least one lateral oxy-burner with an adjustable flame comprises: an injection channel of at least one main jet of oxidant and / or fuel and / or an oxidizing and combustible premix and at least one injector of a fluid actuator opening into or near said channel.

The injection channel and the injector are oriented relative to each other so that the fluid actuator impacts the main jet and thus allows a variation of the orientation of the flame by fluid interaction between the main jet and the fluid actuator (s) of the at least one injector. The injection channel and the injector are advantageously oriented relative to each other so that the fluid actuator impacts the main jet at an angle α greater than 0 ° and less than or equal to 90 °, preferably from 45 ° to 90 ° and more preferably from 60 ° to 90 °.

Preferably, at least one fluid actuator nozzle opens into the injection channel of the oxy-burner, that is to say upstream of the outlet opening of said channel.

In FIGS. 4a, b and c is a schematic diagram of the variation of the flame orientation of an oxy-burner by means of fluid actuators.

As shown in FIGS. 4a and 4c, the main jet 42 to be controlled coming from the injection channel 41 comes into interaction with the fluid actuator 46 coming from the injector 45, thus creating a resultant jet and therefore a flame 48 of different direction from the direction XX 'of the main jet / flame 48 in the absence of a fluid actuator 46 (Figure 4b).

In FIGS. 4a and c, the fluid actuator 46 conveyed by the injector 45 is in the form of a pipe which passes through the material 43, for example a block surrounding the channel 41, this fluid actuator 46 opening through the injector 45, preferably substantially perpendicular to the main jet 42 (a = 900). The main jet 42 opens here inside the material 43, that is to say before the ejection of the main jet 42 of the injection channel 41 through the outlet opening 49.

As illustrated in FIG. 4a, a fluid actuator 46 directed upwards makes it possible to deflect the resulting jet and thus the flame 48 upwards. As illustrated in FIG. 4c, a fluid actuator 46 directed downwards makes it possible to deflect the resulting jet and thus the flame 48 downwards.

A fluid actuator running from left to right makes it possible to deflect the resulting jet and thus the flame to the right and a fluid actuator jet going from right to left makes it possible to deflect the resulting jet and thus the flame 48 to the left (an orientation towards the left is for example an orientation to the charging zone and a right orientation towards the downstream part, sampling area).

It is also possible to deflect the main jet and therefore the flame in an intermediate direction by combining two fluid actuators of different directions. Thus, the combination of a fluid actuator upwards with a actuator going from right to left makes it possible to deflect the resulting jet and thus the flame obliquely upwards and to the left.

The interaction between the two jets takes place at a distance L from the front face 44 from which the main jet 42 opens.

Of course, even if it is preferable according to the invention for the fluid actuator 46 to act on the main jet 42 before the ejection thereof from the front face 44 of the block of material 43, it is possible to envisage a substantially identical action if the injector 45 opens almost at the output 49 of the main jet 42. One can even consider an injector such that the interaction between the fluid actuator and the main jet takes place outside the block of 43, but very close to the outlet opening 49. The distance L may vary as a rule, preferably between 0 and 20 cm, more preferably 0 and 10 cm. The injector 45 may also open up to a few centimeters beyond the point where the main jet 42 opens out. In order to allow the fluid actuator to act as efficiently as possible on the main jet, it is necessary to inject the fluid actuator substantially perpendicular to the direction of the main jet. In practice, to ensure this orthogonality, it will be necessary to provide an injector 45 of height f and thickness e, with the relation = 0.5, preferably 0.5 = 5. ee By appropriate positioning of the injectors 45, the fluid actuators can be used to vary the orientation of the flame in a horizontal plane (flame positioned in a plane perpendicular to the upstream-downstream axis of the furnace, or flame directed towards the charging zone or to the zone of refining / sampling), and / or to vary the orientation of the flame with respect to the charge (flame parallel to the surface of the charge (non-incidence), flame directed towards the charge (incidence), or even flame directed to the vault (non-incidence).

Oxid burners of this type are described in more detail in patent applications FR-A-2903325 and PCT / FR2007 / 051597 of the Applicant. An important advantage of such an orientable flame oxy-burner is that it is possible to vary the angle of incidence of the flame with the load linearly with the ratio of the pulses of the main jet and the fluid actuator used. The ratio of the pulses of the main jet and the secondary jet can therefore be usefully used as a control parameter for the orientation of the burner flame.

The melting zone of the furnace may in particular be equipped in the upstream portion of the furnace with one and preferably several pairs of lateral oxy-burners with adjustable flame.

In the present context, a pair of oxy-burners includes two oxy-burners 17, 17 'mounted on opposite side walls 18 of the furnace and substantially situated at the same distance from the charging zone of the furnace 14.

FIGS. 1 and 2 show two furnaces comprising two pairs of lateral oxy-burners 17, 17 'with an adjustable flame in the part of the melting zone located in the upstream part of the furnace.

As illustrated in FIG. 2, the melting zone 15 of the furnace may in particular be equipped in the upstream portion 11 with one or more pairs of oxy-burners 17, 17 'mounted face to face if it is desired to favor compactness at this point. . As illustrated in FIG. 1, the melting zone 15 may also be equipped in the upstream portion 11 with one or more pairs of staggered side oxy-burners 17, 17 ', which allows for a higher coverage rate and limits the deflection of the flame towards the vault of the oven.

Incidentally (contacting or approximating) the flame of the one or more directional flame side oxy-burners with the charge (illustrated in FIGS. 3 and 5) makes it possible to increase the heat transfer to the charge by several mechanisms: • increase of the temperatures near the surface of the charge, therefore increase of the convective and radiative transfers, • approximation of the zone of turbulent mixing of the flame and the load, therefore increase of the convective exchange coefficients, • recombination of the molecules dissociated in the vicinity of the load, thus additional release of energy in contact with the load. It is also advantageous if the flame is ignited by the charge of the flame of the steerable flame oxy-burner (s) with the charge, which greatly limits the risk of flame-raising and hot-spot formation at the level of the charge. walls.

According to a particularly favorable embodiment, the melting zone 15 is equipped in the upstream portion 11 with one and preferably with several pair (s) of lateral oxyburners 17, 17 'with an adjustable flame, the two oxybrulers 17, 17 'are operated in such a way that when the flames 32, 32' of the two oxy-burners are oriented so that they impact the load 31, 33 at points of impact, the points of impact of the two burners 17, 17 'overlap. Preferably, the two oxy-burners 17, 17 'of a pair of oxy-burners are operated in such a way that, when the flames 32, 32' of the two oxy-burners impact the charge, the points of impact of the two flames overlap permanently. , including when, during the melting process, the orientation of the two flames is changed. Such a form of implementation is illustrated in FIG. 5. By adjusting the flame orientation of the two oxy-burners so that the two points of impact overlap, a stopping point is created making it possible to limit the phenomenon takeoff.

As mentioned above, the orientation of the flame of each steerable flame side oxy burner is preferably adjusted so that the flame sweeps the surface of the charge. In particular, it is proposed, by virtue of the variation of the orientation of the flame, to scan continuously or periodically the surface of the charge covered by the flame of a lateral oxy-burner with an adjustable flame in order to limit the local heating of the charge and to homogenize the heat transfer. Homogenization of heat transfer to the charge generally also makes it possible to improve the symmetry of the fusion of the charge. Preferably, the scanning cycle is optimized to maximize heat transfer by operating the oxy-burner to maintain the greatest temperature difference between the flame and the surface of the charge covered by the flame.

The orientation of the flame of a lateral oxy-burner with adjustable flame installed on the furnace can be set in open loop, for example with an operator adjusting the orientation and / or the movement of the flame in real time or, in a manner automated, with a control device for adjusting each orientable flame oxy burner imposing a predetermined orientation cycle with a predetermined cycle frequency.

The orientation of the flame of a steerable side oxy burner on the oven can also be adjusted in a closed loop.

To optimize productivity or taken from the oven, it is possible in particular to detect the temperature of the flue gases in the oven or leaving the oven, an increase in the flue gas temperature tending to indicate everything else also decreases the thermal efficiency of the oven. It is then possible: • to increase the energy transfer towards the charge in the melting zone by changing the orientation of the flame of at least one and preferably of several oxy-burners with adjustable flame, preferably by non-mechanical actuators, to bring the flame (s) closer to the load when the detected flue gas temperature increases above a predetermined upper limit temperature and • to reduce the energy transfer to the charge in the melting zone by changing the flame orientation of the flame at least one and preferably several oxy-burners with adjustable flame so as to move the flame (s) away from the charge when the detected temperature of the smoke falls below a predetermined lower limit temperature.

It is also possible to detect the temperature of the hearth 34 of the furnace in an area covered by the flame of a steerable lateral oxy-burner, a drop of this temperature generally indicating a decrease in the heat transfer of the flame towards the load. It is then possible: • to increase the energy transfer towards the charge by the flame of said oxy-burner by changing the orientation of this flame, preferably by non-mechanical actuators, so as to bring the flame closer to the charge when the detected temperature of the sole sinks below a predetermined lower limit temperature and • reduce the energy transfer to the charge by the flame of said oxy-burner by changing the orientation of this flame so as to move it away from the charge when the detected temperature of the hearth goes up above a predetermined upper limit temperature.

It is also possible to detect the position of the batch line in the oven, for example with an optical device such as a visible or infrared camera.

It is then possible: • to increase the energy transfer towards the charge in the melting zone by changing the orientation of the flame of at least one and preferably of several oxy-burners with adjustable flame so as to bring the flame (s) closer to the charge when the detected position of the batch line is downstream of a predetermined downstream limit position and • reducing the energy transfer to the charge in the melting zone by changing the flame orientation of at least one and preferably a plurality of oxy-burners with an adjustable flame so as to move the flame (s) away from the load when the detected position of the batch line is upstream of a predetermined upstream limit position.

The oven may be equipped with means for detecting the presence and position of clumps at the batch level in the case of a glass furnace, or more generally the presence of dissymmetries in the melting of the load (for example an asymmetry of the batch line 13). Such means may in particular comprise an optical sensor (visible or infrared camera, for example associated with a shape recognition), it is then possible to operate the lateral oxy-burner (s) with an adjustable flame and to orient the corresponding flame (s) so as to eliminate said dissymmetries. .

By detecting the temperature of the vault in the upstream part of the furnace, preferably in the charging zone, it is possible, when the detected temperature of the vault falls below a predetermined lower limit, to raise the temperature of the furnace. vault above this lower limit by temporarily changing the orientation of the flame of at least one lateral oxy-burner with adjustable flame towards the vault.

It should be noted that through the use of one or more lateral oxy-burners with adjustable flame, the present invention allows a better adjustment or control of the melting process as a function of the distance between the oxybrûleurs and the batch.

The process according to the invention is particularly useful for the melting of low thermal conductivity materials such as glass and enamel melting.

The invention is particularly useful for the oxyboosting of furnaces, and in particular glass furnaces, comprising air burners. In this case, the installation of one or more oxy-burners with adjustable flame according to the invention makes it possible to occasionally increase the drag or to maintain it when for example the regenerators of the oven are damaged or the charge to be melted requires more than energy than the load usually exploited. In the case of an oxyboosting process according to the invention, the implementation of the method may include the installation of one or more oxy-burners with adjustable flame in the upstream part of the furnace. According to a particular embodiment, at least one and preferably at least two oxybrulers with adjustable flame are installed directly upstream of the first furnace air burners. In this way, the melting zone is actually extended upstream of the furnace, these oxyburners with adjustable flame being the first burners encountered by the load at the outlet of the furnace charging zone. In the case of an oven already equipped for oxyboosting, the implementation of the method according to the invention may include the replacement of at least one preexisting oxybruder in the upstream part of the oven with an oxy-burner with adjustable flame.

The invention is also useful for furnaces equipped only with oxy-burners.

Another application is that of furnaces and methods of melting aluminum drosses, especially since metal aluminum can be trapped in gangs of insulating alumina. The prior art then allowing to recover aluminum metal at the cost of a very high energy expenditure.

The present invention also relates to a melting furnace suitable for the melting process described above.

Thus, the invention relates in particular to a furnace for melting a filler, said furnace having an upstream portion and a downstream portion and comprising a charging zone located in the upstream portion, a melting zone located partially in the portion upstream and partly in the downstream part and a sampling zone located in the downstream part. The charge is introduced in solid form into the charging zone. The melting zone is equipped with burners for heating and melting the load. The load is then taken from the oven from the sampling area. According to the invention, the melting zone is equipped in the upstream portion of the furnace with at least one, preferably at least two, more preferably at least three and more preferably at least four oxybrulers. side with adjustable flame. Preferably, said at least one oxy-burner with a directional flame is located directly downstream of the charging zone.

As indicated above, the orientation of the orientable flame is preferably modified or regulated by non-mechanical actuators.

Thus, the variation of the orientation of the flame is preferably provided by fluid interaction between several jets of fluid. In this case, the orientation of the flame is modified or adjusted by means of one or more jets of secondary fluid (s), typically gaseous jets, called fluid actuators.

As described above, in this case, said one or more lateral oxy-burners with adjustable flame can in particular comprise: • an injection channel of at least one main jet of oxidant and / or fuel and / or an oxidizing premix and fuel and at least one injector of a fluid actuator opening into or near said channel.

Said injection channel and said injector are oriented relative to each other so that the fluid actuator impacts the main jet so as to allow a variation of the orientation of the flame by fluid interaction between the main jet and the fluid actuator (s) of the at least one injector.

The furnace according to the invention may also comprise a refining zone located in the downstream part between the melting zone and the sampling zone.

The melting zone may in particular be equipped in the upstream part of one and preferably of several pairs of directional flame side oxy-burners, and in particular of one or more pairs of lateral oxy-burners mounted face to face and / or one or more pairs of sideburners mounted in staggered rows.

According to one embodiment, the melting zone is equipped in the upstream portion with one and preferably with several pairs of orientable flame-side oxy-burners, the furnace comprising a control installation which regulates the operation of the two oxy-burners belonging to one another. to a pair of oxy-burners so that when the flame of the two oxy-burners impacts the load at a point of impact, the points of impact of the two burners overlap.

The oven according to the invention may in particular be provided with a control device for the adjustment of each lateral oxy-burner with a closed-loop or open-loop orientable flame as described above with respect to the melting process.

The invention also relates to a melting installation comprising an oven as described above, a forming device and a feed channel between the sampling zone of the oven and the forming device. The invention relates in particular to such an installation for melting and forming glass.

Claims (18)

A process for melting a charge in an oven having: an upstream portion in which the charge is at least partially present in solid form and a downstream portion in which the charge is wholly present in molten form, the upstream portion being demarcated from the downstream part by a batch line, in which process: • the feedstock is introduced into the furnace in solid form in a charging zone situated in the upstream part of the furnace, • the feedstock is fed in solid form to the charging zone to a melting zone equipped with burners where the charge is heated and melted, said melting zone being located partly in the upstream part and partly in the downstream part of the furnace, the charge in molten form resulting from the melting zone is fed to a sampling zone where the charge in molten form is taken from the furnace, the sampling zone being situated in the downstream portion of the furnace, characterized in that the melting zone is equipped in the upstream part of the furnace with at least one, preferably at least two, more preferably at least three and more preferably at least four flame side oxyburners. adjustable. 2. The method of claim 1 wherein said one or more oxyburners orientable flame are located directly downstream of the charging zone. 3. Method according to one of claims 1 and 2, wherein said one or more oxybrulers with adjustable flame comprise: • an injection channel of at least one main jet of oxidizer and / or fuel and / or an oxidizing and combustible premix and at least one injector of a secondary fluid jet emerging in or near said channel, said injection channel and said injector being oriented relative to each other; in such a way that the secondary fluid jet impinges on the main jet so as to allow a variation of the orientation of the flame by fluid interaction between the main jet and the secondary jet (s) of the at least one injector. 4. Method according to one of the preceding claims, wherein the furnace also comprises a refining zone located in the downstream part between the melting zone and the sampling zone. 5. Method according to one of the preceding claims, wherein the melting zone is equipped in the upstream portion of the furnace of one and preferably several pairs of lateral oxybrulers with adjustable flame mounted face to face and / or staggered . 6. Method according to one of the preceding claims, wherein the melting zone is equipped in the upstream portion of one and preferably several pairs of lateral oxybrulers with adjustable flame whose two oxybrulers are operated in such a way that when the flame of the two oxy-burners impacts the load at one point of impact, the points of impact of the two burners overlap. 7. Method according to one of the preceding claims wherein the temperature of the fumes in the furnace or out of the furnace and wherein: • the energy transfer to the load in the melting zone is increased by changing the orientation of the furnace; a flame of at least one and preferably of several oxyburners with an adjustable flame so as to bring the flame or flames of the charge when the flue gas temperature increases above a predetermined upper limit temperature and • reduces the energy transfer to the charge in the melting zone by changing the orientation of the flame of at least one and preferably several oxy-burners with adjustable flame so as to keep the flame (s) from the charge when the detected temperature of the fumes falls below a predetermined lower limit temperature. 8. Method according to one of the preceding claims, wherein the temperature of the hearth is detected in an area covered by the flame of a lateral oxybrûleur orientable flame and wherein: • it increases the energy transfer to the load by the flame said oxy-burner by changing the orientation of this flame so as to bring the flame of the load when the detected temperature of the bottom falls below a predetermined lower limit temperature and • reduces the energy transfer to the load by the flame said oxy-burner by changing the orientation of this flame so as to move it away from the load when the detected temperature of the hearth rises above a predetermined upper limit temperature. 9. Process according to one of the preceding claims wherein the position of the batch line in the furnace is detected and in which: the energy transfer towards the charge in the melting zone is increased by changing the orientation of the flame; at least one and preferably several oxy-burners with adjustable flame so as to bring the flame (s) of the charge when the detected position of the batch line is downstream of a predetermined downstream limit position and • the transfer is reduced energizing the charge in the melting zone by changing the orientation of the flame of at least one and preferably several oxy-burners with a directional flame so as to move the flame (s) away from the charge when the detected position of the batch line is upstream of a predetermined upstream limit position. 10. A method according to one of the preceding claims wherein the temperature of the vault is detected in the upstream part of the furnace, preferably in the charging zone, and in which, when the detected temperature of the vault drops below of a predetermined lower temperature limit, the temperature of the vault is raised above this lower limit by temporarily changing the orientation of the flame of at least one lateral oxyburner with more adjustable flame towards the vault. 11. Method according to one of the preceding claims for the melting of glass or for the fusion of aluminum drosses. 12. Furnace for melting a feedstock having an upstream portion and a downstream portion, said furnace comprising: a charging zone for charging the charge in solid form, said charging zone being located in the portion upstream, • a melting zone equipped with burners for heating and melting the charge, said melting zone being located partly in the upstream part and partly in the downstream part, • a sampling zone for sampling the furnace from the charge in molten form, the sampling zone being situated in the downstream part, characterized in that the melting zone is equipped in the upstream part of the furnace with at least one, preferably at least two, more preferably at least three and more preferably at least four directional flame side oxy-burners. 13. Oven according to claim 12, wherein said one or more lateral oxybrulers with adjustable flame are located directly downstream of the charging zone. 14. Oven according to one of claims 12 and 13, wherein said one or more oxybrulers with adjustable flame comprise: • a channel for injecting at least one main jet of oxidant and / or fuel and / or an oxidizing and combustible premix and at least one injector for injecting a fluid actuator opening into or close to said channel, said injection channel and said injector being oriented relative to one another; another so that the fluid actuator impacts the main jet so as to allow a variation of the orientation of the flame by fluid interaction between the main jet and the fluid actuator (s) of the at least one injector. 15. Oven according to one of claims 12 to 14, wherein the furnace also comprises a refining zone located in the downstream part between the melting zone and the sampling zone. 16. Oven according to one of claims 12 to 15, wherein the melting zone is equipped in the upstream portion of one and preferably several pairs of lateral oxybrulers with adjustable flame mounted face to face and / or staggered . 25 17. Oven according to one of claims 12 to 16, wherein the melting zone is equipped in the upstream portion of one and preferably several pairs of lateral oxybrulers with adjustable flame, the furnace comprising a control installation which adjusts the operation of the two oxy-burners belonging to a pair of oxy-burners so that when the flame of the two oxy-burners impact the charge at a point of impact, the points of impact of the two burners overlap. 18. Glass melting plant, comprising a furnace according to one of claims 15 to 21, a forming device and a feed channel between the sampling zone of the furnace and the forming device.