RU2433343C2 - Burner with varied direction and/or opening of torch and method of charge heating with application of this burner - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: burner comprises a channel to supply a primary jet of oxidiser or fuel or previously produced mixture of oxidiser and fuel to the main output hole, at least one secondary pipeline to inject a secondary jet, in which at least one specified secondary pipeline exits into the channel via a secondary hole arranged in front of the main hole, and is arranged relative to the channel so that in the point of interaction between the appropriate secondary jet and the primary jet the angle θ between the axis of the appropriate secondary jet and the plane perpendicular to the axis of the primary jet, exceeds or is equal to 0° and is less 90°, preferably makes from 0° to 80°, more preferably - from 0° to 45°, and the specified at least one secondary hole is away from the main hole at the distance L, less or equal to the tenfold square root of the main hole section s, preferably L ≤ 5*√s, more preferably - L ≤ 3*√s, the burner comprises facilities to adjust the pulse of each appropriate secondary jet, at the same time the specified burner makes it possible to vary direction and/or opening of the torch by variation of the pulse of at least one appropriate secondary jet.

EFFECT: invention makes it possible to vary direction or opening of torch in the wide range, without interruption of burner or furnace operation.

22 cl, 15 dwg

Description

Technical field

The invention relates to a burner that allows you to change the direction and / or solution of the torch, while the said burner contains at least one injection channel of at least one primary or primary jet and at least one injection channel of the acting or secondary jet. Typically, the primary stream is a stream of oxidizing agent and / or fuel and / or a preformed oxidizer-fuel mixture.

The invention also relates to the use of said burner for controlling the direction and / or torch solution. It also relates to a method of heating the charge using this burner, in which the direction and / or solution of the torch is changed.

State of the art

Most industrial furnaces or boilers use burners that operate in a combustion mode without preliminary mixing, that is, in which the oxidizing agent and fuel are delivered separately to the combustion site. In this case, the mixing of fuel and oxidizer occurs partially (stabilization of the flame in the embrasure of the burner or in the prechamber) or completely inside the combustion chamber. This mixing is regulated by the design and operating parameters of the burner and determines the characteristics of the burner (area of work, heat transfer to the heated charge, emission of pollutants, etc.). In practice, when designing a burner, the conditions for the interaction of various jets or flows of oxidizing agent and fuel used in the burner are determined. After the burner is sold, only the operating conditions can be changed. The same applies to the so-called “premixing” burners, in which the oxidizer / fuel mixture is produced in the burner at the inlet of the combustion chamber. In this case, the reagents enter only through one tube.

The operating conditions of industrial combustion processes may vary over time. This applies to cyclic processes, but it can also relate to continuous processes in which the characteristics of the heated mixture can vary depending on production needs. As a rule, this applies to any production plant that is susceptible to aging or sensitive to changing environmental conditions.

To adapt the characteristics of the burner to changing operating conditions, the operator most often has two parameters: the operating power of the burner and the level of excess oxidizer (excessive oxygen stoichiometry).

Some combustion technologies allow you to work in discrete modes with a very limited number of them. This, for example, refers to the so-called “double pulse” burners, which use two different injection systems, depending on whether the burner requires a low or high pulse. These two operating modes allow you to expand the area of operation of the burner or change the length of the torch for a given operating point.

However, changing the operating point and / or operating mode is often insufficient to optimize the performance of the burners or processes using these burners in all conditions. For example, the cyclic supply of solids to the melting furnace at ambient temperature forces the operator (or control system) to increase the heating power in order to ensure melting as quickly as possible (in order to increase productivity), without compromising the properties of the melted charge (product quality) and without overheating the furnace (time equipment services). This trade-off between performance and quality and / or service life depends, in particular, on the ability of the system to transfer energy to the charge, avoiding local overheating of the charge or furnace refractories. This compromise is expressed in the duration of the smelting, beyond which any gain in productivity will be lost due to deterioration in product quality or shortened furnace life.

A burner is known from WO-A-9744618 containing a central jet of fuel surrounded first by a plurality of primary jets of an oxidizing agent and then by a plurality of secondary jets of an oxidizing agent. Thus, during operation, you can change the position of the flame.

However, the maximum deviation of the torch in practice is limited to a value of about 15 ° from the central position to the extreme position (no more than 30 ° in total) and does not allow the flame torch to process the charge by scanning over a large area, and the design of the corresponding burner is relatively complex, since it requires a lot of openings for the primary jets of the oxidizing agent and a plurality of openings for the secondary jets of the oxidizing agent.

In addition, the properties of the torch change depending on its position, since the properties of the mixture change together with the angle of inclination (the mixture is “external” relative to the burner block), which leads to fluctuations in the emission of pollutants, the quality of the radiation transfer (flame brightness) and the length of the torch ( peak position of heat release).

The objective of the invention is to develop a reliable and optimal burner that allows you to change the direction and / or solution of the torch in a wide range, without stopping the operation of the burner or furnace.

Disclosure of invention

The invention provides control of the direction and / or torch solution due to the interaction of a jet of fluid (called the primary or main jet) and at least one other jet of fluid (called the secondary or acting jet), while the interaction between the jets occurs inside the means supplying this the main stream (tube, embrasure, etc.) before said main stream leaves said means.

The burner in accordance with the present invention contains a channel for supplying a primary stream to the main outlet. Typically, the primary stream is a stream containing fuel, an oxidizing agent, or a preformed fuel-oxidizing mixture. The burner also comprises at least one secondary conduit for injecting a secondary stream. The fluid injected in the secondary stream may or may not belong to the same category as the fluid of the primary stream. The secondary stream may be, in particular, an inert stream, such as water vapor or combustion products, such as recycled fumes.

Said at least one secondary conduit enters the primary stream channel through a secondary opening located in front of the main outlet. The secondary pipeline is positioned relative to the channel so that at the point of interaction (the center of inertia of the imaginary surface common to the two flows) between the secondary jet emerging from this secondary pipeline (hereinafter referred to as the corresponding secondary jet) and the primary jet, the angle θ between the axis of the corresponding secondary the jet and the plane perpendicular to the axis of the primary jet exceeded or was equal to 0 ° and was less than 90 °, preferably ranged from 0 ° to 80 °, even more preferably ranged from 0 ° to 45 °. When the angle θ = 0 °, which is preferred, the axis of the corresponding secondary stream is in a plane perpendicular to the axis of the primary stream.

The said at least one secondary hole is spaced from the main hole by a distance L less than or equal to ten times the square root section s of the output main hole, preferably L≤5 * √s, even more preferably L≤3 * √s.

In the publication “Proceedings of FEDSM'02 Joint US ASME-European Fluid Engineering Division Summer Meeting of July 14-18, 2002” and in the article “Experimental and numerical investigations of jet active control for combustion applications”, V. Faivre and Th. Poinsot , Journal of Turbulence, Volume 5, No. 1, March 2004, p. 25, discloses the use of a special configuration of four secondary jets around the main jet to stabilize the flame due to the interaction between the secondary jets and the primary jet. In this case, a wider angle of dispersion is noted.

According to the invention, the burner is equipped with means for controlling the pulse of at least one secondary stream.

As will be described in detail below, due to this, the invention allows you to change the direction and / or solution of the torch exiting the burner by changing the momentum of at least one secondary stream using the above-mentioned means.

Preferably, the pulse control means of the at least one secondary jet are means for controlling the relationship between the secondary jet pulse and the primary jet pulse.

Thus, the invention provides a wide range of changes in direction and / or torch solution, without resorting to mechanical means, which are potential sources of malfunction, in particular in an aggressive environment, such as high-temperature combustion chambers and / or a contaminated or corrosive atmosphere.

The controls provide, in particular, the active or dynamic control of the pulse of the at least one secondary jet, that is, they allow you to change the pulse or pulses without stopping the burner / without interrupting the torch. Thus, the device in accordance with the present invention also provides a dynamic change of direction and / or torch solution.

Preferably, the number of secondary jets interacting with the primary jet to achieve the desired flare effect is minimized in order to limit the complexity and cost of manufacturing the burner, as well as the complexity and cost of the fluid flow control feed system, if the secondary jets are controlled independently. For example, with only one secondary stream, a unidirectional effect can be obtained.

Among the terms used in the present description, some should be defined more precisely in the framework of the present invention, in order to better limit their meaning:

• The direction of the jet / torch is defined as the normal unit vector in the cross section of the fluid channel / torch, directed towards the flow, that is, from the entrance to the exit.

• “Thickness e” denotes the size of the secondary pipe in the direction of flow of the primary stream (in the direction of the arrow in FIG. 1). In the particular case shown in this figure 1, e denotes the diameter of the secondary pipe 21 at the level of the secondary hole 31, since in this example this secondary pipe 21 is cylindrical.

• The “solution” of the jet / torch means for the jet / torch exiting from the cylindrical channel, such as channel 10 in FIG. 1, the angle between the longitudinal axis of the channel and the forming surface of the jet / torch at the channel exit. In the absence of interaction with the secondary stream, the generatrix has a slope of about 10 to 15 ° with respect to this axis, and according to the invention this slope can reach 70 ° or more (see figa). In a broader sense, the term "solution" refers to the angle between the direction of flow in the channel, when the cross section of the latter is not round, and the generatrix.

Brief Description of the Drawings

The invention is further explained in the description of non-limiting options for its implementation with reference to the figures of the accompanying drawings, including:

figure 1 is a schematic diagram of a burner (with premixing) in accordance with the present invention for controlling a torch by the interaction of jets;

figure 2 - regulation of the burner in accordance with the present invention mounted on the combustion chamber;

figa and b depict a burner for controlling the direction of the torch, while figa shows a cross-sectional view, and figv is a view in longitudinal section of a burner containing four secondary jets, spaced respectively 90 ° relative to each other and directed perpendicular to the direction of the primary stream;

figs, D and E - the use of the plate to transform the nozzle with parallel primary and secondary (s) jets in the burner in accordance with the present invention;

figa and b are views in longitudinal and transverse section of the burner, providing control of the solution of the resulting stream;

figure 5 depicts the use of a burner to change the torch using two (resulting) jets: a jet of fuel and a stream of oxidizer;

6 is a tube-in-tube burner equipped with an embrasure;

figa, b and C depict a burner with separate jets;

Fig. 8 depicts a function of the heat flux density of a torch as a function of the distance to the injection point at different angles of inclination;

figa and b depict embodiments of the management solution of the torch;

figa and b - the influence of the control parameter on the deflection of the flame and heat transfer to the charge;

11 depicts the angle of the torch solution depending on the ratio of the impulses of the jets;

12 illustrates an example application of a system in accordance with the present invention for heating a charge with a change in the slope of the torch;

Fig - use of the invention for heating the mixture with lateral movement of the torch;

Fig. 14 shows the use of an adjustable torch solution for involving furnace gases;

Fig - the level of emissions of the torch depending on the control parameter;

Fig - execution of burner protection using the embrasure;

Fig - execution of the protection of the burner using the clutch.

In the following description, the same numeric positions will be used, on the one hand, to indicate the primary jet and the channel in which it passes, and, on the other hand, to indicate the secondary or acting jet and the corresponding secondary conduit in which this secondary stream passes.

Figure 1 shows a schematic diagram of a method for controlling a torch in a burner in accordance with the present invention.

The burner contains a channel 10, which allows you to feed the primary stream into the output main hole 11.

The primary stream enters through channel 10 and interacts with the secondary stream exiting the secondary pipe 21, forming a torch 1 at the outlet of the outlet 11 with a direction and / or solution different from the direction and / or solution of the torch in the absence of a secondary stream.

At least one secondary conduit 21 for injecting a secondary jet enters the channel 10 through the secondary opening 31. This secondary conduit 21 is positioned relative to the channel 10 so that at the point of interaction between the corresponding secondary stream and the primary stream, the angle θ between the axis of the secondary stream 21 and the plane perpendicular to the axis of the primary jet 10 exceeded or was equal to 0 ° and was less than 90 ° (θ = 0 ° in figure 1).

The secondary hole 31 is spaced from the main hole 11 by a distance L, while L is less than or equal to 10 × √ s (s = section of the main hole 11). The distance L allows you to influence the effect of the secondary jets on the primary jet with identical corresponding pulses. For example, to achieve the maximum directivity effect, this distance should be minimized. As a rule, for oxygen burners and for values of developed power of the order of a megawatt, the length L will be less than or equal to 20 cm, preferably less than or equal to 10 cm.

The burner contains means for controlling the impulse of the secondary jets. These tools can be selected among devices for mass flow control, pressure reduction control, channel cross-section control, as well as among temperature control devices, chemical composition control, and pressure control devices.

These means may preferably be means for adjusting the relationship between the secondary jet pulse and the primary jet pulse.

The controls allow you to activate or deactivate the secondary stream or secondary stream (flow or lack of flow of the considered secondary stream) in such a way as to dynamically change the direction and / or solution of the torch.

It is preferred that the controls also allow dynamically increasing and decreasing the (non-zero) momentum of the secondary stream or secondary streams, or increasing and decreasing the ratio between the momentum of the secondary stream and the momentum of the primary stream.

The burner can be supplied with fuel and oxidizer using the oxidizer injection channel and at least one fuel injection channel arranged concentrically, or using the oxidizer injection channel and at least one fuel injection channel, made separately from each other and preferably parallel to each other.

Preferably, the burner comprises a material block 5, such as a block of refractory material, in which at least a portion of the channel 10 is located, with the outlet main opening 11 being located on one of the sides or surfaces of the block: on the front side 6.

In FIG. 1, the secondary stream enters through a secondary conduit 21 that passes through block 5, and preferably this secondary stream exits substantially perpendicular to the primary stream.

The interaction between the primary jet and the secondary jet occurs at a distance L from the front side 6 of the block onto which the primary jet channel 10 exits, and the said distance L may vary, as indicated above.

According to an embodiment allowing changing the direction of the torch and shown in FIGS. 3A and 3B, the burner comprises at least one secondary conduit 321, 322, 323 and 324, which are positioned relative to the primary jet channel 310 so that at the level of the corresponding secondary the openings 331, 332, 333 and 334 (that is, the secondary opening through which the secondary conduit enters the main channel) the axis of the primary jet and the axis of the corresponding secondary stream intersected or almost intersected.

This arrangement between the channel and the secondary pipeline allows you to change the angle between the axis of the torch and the axis of the primary jet in front of the secondary hole by changing the momentum of at least one corresponding secondary jet.

If, in the absence of a jet, the torch emerging from the outlet of the main opening 311 is perpendicular to the plane of FIG. 3A, injection of the jet through the secondary conduit 323 allows the torch to be deflected to the right in FIG. 3A, i.e., in the same direction as the direction of the jet flow, exiting 323. If the secondary jet is simultaneously injected through the secondary conduit 324, depending on the relative momentum of the jets leaving 323 and 324, a torch can be obtained that is deflected in the direction (in projection onto the phi plane .3A) which can constantly oscillate between the directions of the jets emerging from the 323 and 324 (to the right and down in Figure 3A).

Preferably, the burner comprises at least two secondary conduits that are positioned relative to the channel 310 so that, on the one hand, two corresponding secondary holes are in the same section of the channel 310, and that, on the other hand, are at the level of these secondary axle holes the corresponding secondary jets intersected or almost intersected with the axis of the primary jet. In this case, two corresponding secondary holes can be located on both sides of the axis of the primary jet (right and left in the case of holes 331 and 333, lower and upper in the case of holes 332 and 334), while the two secondary holes and the axis of the primary stream are preferably in one plane (horizontal in the case of holes 331 and 333, vertical in the case of holes 332 and 334).

According to another preferred configuration, at the level of the two respective secondary holes, the plane formed by the axis of the primary stream and one of the two corresponding secondary holes is perpendicular to the plane formed by the axis of the primary stream and the other of the two corresponding secondary holes. For example, the horizontal plane formed by the axis of the channel 310 and the secondary hole 331 is perpendicular to the vertical plane formed by this axis and the secondary hole 332.

These two embodiments can be combined. In this case, as shown in FIGS. 3A and 3B, the burner comprises at least four secondary pipelines 321, 322, 323 and 324, which are positioned relative to the channel 310 in such a way that:

(1) four respective secondary holes 331, 332, 333 and 334 are in the same cross section of the channel 310 and

(2) two of these respective secondary holes 331 and 333 form the first plane with the axis of the primary jet and are located on both sides of this jet, two other secondary holes 332 and 334 form the second plane with the axis of the primary jet, while preferably the first plane is perpendicular to the second plane.

This arrangement allows you to change the direction of the torch in the first and second plane (for example, in the horizontal plane and in the vertical plane) and, optionally, in the direction of one or the other of the two secondary holes located in each plane (for example, left and right in the horizontal plane and up and down in the vertical plane), and, as mentioned above, in any intermediate direction.

At the level of the four respective secondary openings 331-334, the axes of the four respective secondary jets are preferably in the same plane perpendicular to the axis of the primary jet 310.

The invention also allows the interaction between the primary jet and one or more secondary jets in such a way as to create, maintain or enhance the rotation of the fluid stream resulting from this interaction, and therefore, the torch around its axis. This interaction allows you to change the solution of the torch.

As shown in FIGS. 4A and 4B, the burner may be equipped with at least one secondary conduit 421-424, which is positioned relative to the primary jet channel 410 so that at the level of the corresponding secondary opening 431-434, the axis of the corresponding secondary jet 421- 424 was not coplanar or substantially coplanar with the axis of the primary jet 410, and the at least one secondary conduit 421-424 preferably exits tangentially into the primary jet channel 410. Thus, the interaction between the primary stream and the secondary stream gives the primary stream a rotational momentum.

The burner may contain two secondary pipelines 421 and 422 located with respect to the primary jet channel 410 so that at the level of two corresponding secondary holes 431, 432 the axes of two respective secondary jets are not coplanar with the axis of the primary jet 410, while both secondary jets oriented in one direction of rotation around the axis of the primary jet. Thus, both secondary jets contribute to the rotational momentum imparted to the torch.

Preferably, both secondary holes are in the same cross-section of the channel 410 / in one plane perpendicular to the axis of the primary jet. They can be located on both sides of the axis of the primary jet (holes 431 and 433 or 432 and 434). They can also be positioned so that the plane formed by the axis of the primary stream and one of the secondary holes 431 is perpendicular to the plane formed by the axis of the primary stream and the other of the two secondary holes 432.

According to an embodiment, the burner comprises at least four secondary pipelines 421-424, which are located with respect to the primary jet channel 410 so that at the level of the respective secondary holes 431-434 the axes of the respective secondary jets are not substantially coplanar with the axis of the primary jet. Two of the two respective secondary holes 431 and 433 are substantially coplanar with the axis of the primary jet 410 in the first plane and are located on both sides of the axis of the primary jet. Two other corresponding secondary holes 432 and 434 are essentially coplanar with the axis of the primary jet 410 in the second plane and also are located on both sides of the axis of the primary jet, with four corresponding secondary jets oriented in the same direction of rotation about the axis of the primary jet. The first and second planes can be, in particular, perpendicular to each other. It is also preferred that the four corresponding secondary holes are in the same cross section of the channel 410.

To impart a rotation impulse to the primary jet, as well as to change the torch solution, it is preferable to make sure that at the level of the secondary hole where the primary jet and the corresponding secondary jet interact, on the one hand, the axis of the secondary jet belongs to a plane perpendicular to the axis of the primary jet at this point , and, on the other hand, the angle between the axis of the secondary jet and the tangent to the secondary hole (or, more precisely, to the imaginary surface of the channel of the primary jet at the level of the secondary hole) in this plane It ranges from 0 to 90 °, preferably from 0 to 45 °.

Figures 4A and 4B show an exemplary embodiment for controlling a torch solution. The primary stream (which runs from left to right in channel 410 in FIG. 4A) encounters secondary jets exiting secondary lines 421, 422, 423 and 424 (shown in FIG. 4B, which shows a transverse section along the plane AA of FIG. 4A) . These secondary jets act on the primary jet in the direction tangential to channel 410, thus allowing, depending on the momenta of these different jets, more or less significantly “open” the torch. This effect of the solution is mainly due to the fact that the secondary jets and the primary jet have axes that do not intersect, although physical interaction between the jets occurs. This leads to the rotation of the resulting jet and, therefore, the torch around its axis.

It is also possible to combine an embodiment in one burner, which allows changing the direction of the torch, with any of the embodiments described above, which allow creating, maintaining or enhancing the rotation of the resulting jet and thus changing the torch solution.

Thus, to achieve both an effect in direction and rotation, the above options should be combined. To obtain a dynamic change in directivity and rotation effects, for example, several secondary jets injection systems can be provided.

By providing separate secondary pipelines with means for controlling the momentum of the secondary stream, such as supply valves, it is thus possible to continuously or periodically change the shape and direction of the resulting stream by simply actuating the said control means (valves).

In order for the secondary jet to act as efficiently as possible on the primary jet, the acting jet should be injected substantially perpendicular to the direction of the main jet.

For optimal operation, the burner should contain at least one secondary pipe 21 located in relation to the primary jet channel 10 so that at the level of the corresponding secondary hole 31 this pipe has a thickness e and a height l, where l≥0.5 × e and preferably 0.5 × e≤l≤5.0 × e (see FIG. 1). A minimum height greater than or equal to 0.5 × e allows for optimal interaction between the corresponding secondary stream and the primary stream.

For example, in practice, to obtain a secondary stream such that at the point of interaction between this secondary stream and the primary stream, the angle θ between the axis of the secondary stream and the plane perpendicular to the axis of the primary stream is 0 °, preferably the secondary conduit must have a direction substantially perpendicular to the axis of the primary jet over a length l, which should preferably be from 0.5 to 5 times the thickness e (size in the direction of flow of the main fluid) mentioned pipeline (e is the diameter of the pipeline, if it has a cylindrical shape). The length l can also exceed 5e, but this does not lead to a significant additional effect of the secondary jet on the primary jet. For example, for a burner with gaseous hydrocarbon injection under ambient conditions and with oxygen injection, at least l = 5 mm for a 100 kW burner and l = 50 mm for a 10 MW burner are obtained.

The burner may comprise an embrasure or pre-combustion chamber (for example, made of ceramic) located at the end of the channel, with at least one secondary conduit at least partially located inside the embrasure / pre-chamber.

The channel of the primary stream can be made completely or at least partially in the form of a primary pipe for injection of the primary stream. This primary pipe enters the primary hole.

This primary opening may coincide with the outlet main opening of the channel.

When, as shown in FIGS. 3C, 3D and 3E and FIG. 6, the primary pipe 308, 608 ends before the output main hole 311, 611, the primary hole 309, 609 is located in front of the main hole 311, 611. In this case, at least at least one secondary hole 334, 632, 634 may be between the primary hole 309, 609 of the primary pipe 308, 608 and the main channel opening 311, 611.

Figure 6 shows, in particular, an example embodiment of the invention in a tube-type burner in a tube containing a prechamber, which is connected to the burner inside the ceramic embrasure and in which flame stabilization occurs (as described, for example, in patent applications No. US-A-5772427 and US-A-5620316, filed in the name of the applicant, and is commercially used by the applicant under the trademark ALGLASS). 6, the embrasure block 605 comprises a cavity 671 (or prechamber) into which the double tube exits.

Thus, the primary jet channel 610 is a primary conduit 608 that exits the primary hole 609 into the cavity 671, which exits through the output main hole 611 located on the front side of the embrasure behind the primary hole 609.

In the embrasure (block) 605 of the burner, several secondary pipelines 622, 624 are made, extending essentially perpendicular to the axis of symmetry X-X of the burner into the channel 610 and, in particular, into the cavity, respectively, through secondary openings 632 and 634 located at a distance L from the outlet of the main hole 611.

The double tube itself schematically consists of a central fuel injection tube (preferably) covered by a ceramic tube into which the oxidizing agent is injected, while both fluids are mixed in the cavity 671.

In this embodiment, the oxidizing agent and fuel (and, if necessary, combustion products) injected coaxially through the tubes are mixed in front of the secondary openings 632, 634. The direction and / or solution of the torch is then controlled by the action and, in particular, by a controlled pulse of at least one acting jet 622, 624.

For optimal operation of the burner in accordance with the present invention, the primary stream channel must comprise at the level of said at least one secondary hole an unblocked or at least substantially unblocked fluid channel in the continuation of said at least one corresponding secondary conduit, so that to provide effective interaction between the at least one corresponding secondary stream and the primary stream. Typically, the cross section of the primary jet channel should limit the non-blocked or at least substantially non-blocked fluid channel at the level of said at least one secondary orifice. This is shown in FIG. 6, where the central fuel supply pipe ends at the level of the primary hole, that is, much ahead of the secondary holes.

On figs, D and E shows another embodiment of the burner, in which the primary pipe 308 ends before the output of the main hole 311.

On figs shows a version similar to figv, but in which the nozzle 345 has two parallel channels (primary pipe 308 and secondary pipe 324), with both channels 308 and 324 facing the front side of the nozzle. A plate 342 is mounted on this front side, which allows the secondary stream of the secondary pipe 324 to be directed towards the primary stream exiting the primary pipe 308, and in particular perpendicularly or substantially perpendicularly to the primary stream. Thus, it is possible to deflect the torch, for example, in the direction shown in FIG. 3C by arrow 344. (The direction 344 of the torch will depend on the ratio of the pulses of the primary and secondary jets). Thus, by varying the momentum of the secondary pipe by means of controls, it is possible to obtain a variable direction of the torch, allowing the torch to treat the entire surface, such as the surface of a heated liquid bath.

3D, an exploded view shows a nozzle 345 on which a plate 342 is mounted (by means not shown in this figure), in this case in the form of a hollow side cylindrical part 350, which is pressed against the end of the nozzle 345, while the hole 346 in the plate is located at the outlet of the primary pipe 308.

FIG. 3E shows the bottom (inner part) of this plate 342, the inner side 349 of which contains a cavity 347 into which a secondary jet exits the secondary conduit 324, then encounters a substantially normal perpendicular primary stream exiting the primary conduit 308 through the slot 348 above the main outlet 346. The torch 344 (FIG. 3C) exiting from this opening 346 is thus deflected downward (with respect to FIGS. 3C, D and E).

It should be noted that the ability to use the plate to give the desired direction to one or more secondary jets to the corresponding points of their interaction with the primary jet is not limited to secondary jets directed in such a way as to change the direction of the torch, but can also be used for the secondary jets described above, which allow changing torch solution.

The invention also relates to a method for dynamically or actively controlling the characteristics of a combustion system or burner using one or more secondary jets acting on the primary jet to change the jet stream and produce a torch, the direction and / or solution of which can be changed depending on the characteristics (in particular, direction and amount of movement) of the primary and / or secondary jets. This method can be used to control in a closed or open circuit the characteristics of the combustion system by applying injections of jets of a fluid (liquid, gaseous or solid).

Figure 2 shows a method for controlling the characteristics of the burner 210 in accordance with the present invention mounted on the furnace 212.

Sensors 214, 216 and 217 respectively measure values characterizing the products of combustion, the operating conditions of the combustion or furnace, and the operation of the burner. The data of these measurements is transmitted along lines 218, 219 and 220 to the controller 215. This controller, depending on the set values determined by the characteristic values, determines the operating parameters of the secondary jets in such a way as to maintain the characteristic values at their set values, and using line 221 transmits these parameters to the burner controls 211.

Preferably, the burner in accordance with the present invention comprises means for controlling the pulses of the primary and / or secondary jets or means for controlling the ratio of the pulses of the primary and secondary jets (jets). This ratio is a function of the ratio of the cross section of the primary jet channel and the cross sections of the secondary pipelines, the ratio of the flow rates in the secondary pipelines to the flow rate of the resulting jet feeding the torch, and the ratios of the densities of the fluids of the primary jet and the secondary jet or secondary jets. (In the following sections, when considering one of these relations, the other two will be considered constant).

The more the ratio of the channel cross section and the secondary pipe cross section increases at the level of the corresponding secondary hole, the more (with constant corresponding flow rates) the corresponding secondary stream acts on the primary stream. Preferably, the ratio of the cross sections is selected in the range from 5 to 50, and even more preferably from 15 to 30.

The ratio of the flow rate of all secondary jets to the total flow rate should range from 0 (no secondary jets) to 0.5 and preferably from 0 to 0.3, even more preferably from 0 to 0.15; in this case, the greater the ratio of costs, the greater the deviation and / or the torch solution will be.

The ratio of the density of each fluid that is part of the secondary jets to the density of the fluid of the primary medium allows you to control the effect of the secondary jets. The smaller the value of this ratio, the more significant is the effect of the secondary jet on the primary jet at a constant flow rate. For practical reasons, the same fluid is often used in the secondary jets and in the primary jet (the ratio is unity). To increase (at a constant mass flow rate) the effects of the secondary jets, a fluid with a lower volumetric mass is used than the fluid of the primary jet. The fluid in the secondary jets is selected depending on the intended application. For example, to control the deviation of the air stream, you can use a mixture of air and helium (lower density) or to control the involvement of combustion products in the propane torch, to control the main stream of fuel and / or oxidizer secondary stream of water vapor. Typically, the ratio of the density (or bulk density) of a denser fluid to a less dense fluid can range from 1 to 20, preferably from 1 to 10, and even more preferably from 1 to 5.

The injection section of the channel and / or secondary pipelines may have a different geometric shape, in particular round, square, rectangular, triangular, elongated, lobed, etc. The geometric shape of these injection sections affects the development of instability of the resulting jet / flame. For example, the jet at the outlet of the triangular nozzle will be more unstable than the jet exiting the round nozzle, and this instability helps to mix the resulting jet with the environment. In the same way, an elongated nozzle will contribute to the asymmetric development of the jet near the nozzle, in contrast to a round or square nozzle.

As for the physicochemical properties of the fluid used to produce the secondary jets, they can be selected to control some properties of the resulting stream. For example, you can change the reactivity of a mixture of the main jets of fuel (for example, natural gas), an oxidizing agent (for example, air) by using oxygen (or another oxidizing agent) and / or hydrogen (or another combustible substance).

If immediately before the point of interaction of the primary and secondary jets, the end of the primary fuel channel is equipped with a nozzle containing a converging / diverging element (also called the Laval nozzle in the literature), it is possible to obtain a primary fluid stream at the output of the diverging element (which is itself known) and the resulting stream, for example, a supersonic oxygen stream, which in this case will have a variable direction (if necessary, a variable solution, but with a loss of supersonic speed, which, according to allows you to alternate supersonic and subsonic speeds in some processes). The Laval nozzle can also be placed on the resulting stream in front of the main outlet.

According to a variant of the method, at least two secondary jets are used in such a way as to obtain a change in the direction of the torch in one plane (for example, left and right or up and down). You can also use at least two secondary jets to obtain a change in the direction of the torch in at least two intersecting planes. These two options, taken separately or in combination, allow scanning to process at least part of the surface, such as the surface of the charge.

When using a secondary jet, the axis of which does not intersect or almost does not intersect with the axis of the primary jet, the torch solution above the charge can be changed simply or in combination with scanning processing.

Means are preferably provided for controlling the amount of movement of the primary stream and / or at least one secondary stream.

It should be noted that although the burner and method described above were presented for an application with only one primary stream that interacts with one or more secondary streams, it is obvious that the present invention also relates to such a burner for creating one or more torches with variable solution and / or direction using a plurality of primary jets that interact with one or more secondary jets.

Figure 5 shows how the burner in accordance with the present invention allows to obtain a variable torch using two primary jets: the primary jet of fuel and the primary jet of oxidizer. Each primary stream interacts with one or more secondary streams. Due to this interaction, the two resulting jets leaving the burner, and therefore the torch, have a variable direction and / or solution.

FIG. 5A schematically shows the resulting fuel jet 61, over which the resulting oxidizer jet 62 is located in a situation in which none of these jets is controlled by interaction with one or more secondary jets. 5B shows the same resulting jets, but in a situation where they are controlled or deflected oppositely to each other (converging jets). The jet 60 is deflected downward by the secondary jet 62, while the jet 61 is deflected by the secondary jet 63 directed upward (as opposed to 61). On figs shows the resulting jets in a situation where these jets are controlled or deviated in one direction (upward in figs. 5c): the secondary jets 63 and 65 act from bottom to top respectively on the main jets 61 and 60, which leads to the resulting jets, pointing up. These three examples allow you to get torches with significantly different direction and morphology (length, flattening, etc.). Torch 64 will be very wide in the mid-horizontal plane of the two jets, while torch 67 will be highly deflected upward.

According to the invention, at the point of interaction between the secondary jet and the primary jet, the axis of the secondary jet forms, with a plane perpendicular to the axis of the primary jet, an angle less than 90 ° and preferably equal to 0 °. However, as shown in FIGS. 3C and D, for reasons of size, the channels supplying these jets are most often substantially parallel. In order to redirect the secondary stream at the level of the zone of interaction of the two streams, an end piece can be fixed on the end of the burner with parallel channels, hereinafter referred to as the injection plate, the function of which is to transform the direction of the secondary stream, initially parallel to the primary stream, into the secondary stream acting on the primary stream, wherein the axis of said secondary stream is preferably in a plane perpendicular to the axis of the primary stream.

At the same time, the use of a burner for high-temperature processes (Т> 1000 ° С) can lead to overheating and destruction of the injection plate.

To solve this problem, when determining the size of the injection plate, they try to reduce the front surface of the burner exposed to radiation in a high-temperature chamber. To do this, reduce the l / e ratio.

You can also use one of the two solutions shown in Figs. 16 and 17. According to the first solution (Fig. 16), the burner 500 is placed inside the refractory part 501, whose geometrical shape and relative position of the burner / embrasure protect the burner from too much radiation. The position or degree of burial of the burner in the embrasure should be sufficient to protect it from radiation, but should not limit the amplitude of the directivity of the torch. To do this, you can change the geometry of the embrasure, removing part of it along the line 160 shown in Fig. 16 by a dotted line at an angle α.

Preferably, the R / d ratio should be in the range of 0.3 to 3, while the angle α should be in the range of 0 °, 60 °.

A second solution is to install a clutch type refractory directly on the tip of the burner (where the main outlet is located), as shown in FIG. This solution eliminates the use of embrasures of complex geometric shapes. The dimensions of the coupling are determined so that they do not limit the amplitude of the directivity of the nozzle. This, in particular, means that the thickness f of the coupling must be small (less than the diameter of the main jet) or that the material for making this coupling must have very low thermal conductivity. For example, alumina is preferred.

The invention also relates to a method of heating a charge with a burner, in which the direction (and / or solution) of the torch is changed with respect to the charge. As indicated above, the invention allows, in particular, to use one or at least two secondary jets in such a way as to obtain a change in the direction of the torch in the plane (for example, left and right or up and down). You can also use at least two secondary jets in such a way as to obtain a change in direction in at least two intersecting planes. These two options, taken separately or in combination, allow scanning to scan at least part of the surface of the mixture.

According to an embodiment, the charge is heated in such a way that in the first phase the torch is directed towards the charge and in the second phase the torch is directed substantially parallel to the charge.

In particular, during the first phase, the angle of injection of the torch can be from about 90 ° to 5 °, typically from about 90 ° to 10 °. During the second phase, the angle of injection of the torch is usually about 5 ° to 0 °.

Preferably, the angle of injection of the torch during the first phase is from 5 ° to 75 °, and more preferably from 25 ° to 45 °.

On Fig shows three profiles of the heat flux transferred by the torch to the charge at an angle of inclination of the torch to the charge, depending on the distance to the point of injection of the torch reagents. There is a very strong increase in the heat flux transferred to the charge, with an increase in the slope of the torch. For zero slope (α = 0 — see FIG. 12), the heat flux is substantially constant over the entire length of the flame; when tilted at 15 °, the transmitted flux increases very quickly, then more slowly starting from point A, while when the torch is tilted at 30 °, the transmitted flux increases extremely quickly to point B, then slower essentially to point A, from which heat transfer decreases .

On figa and b shows the angle of the torch, depending on the ratio of the flow rate of the secondary (acting) jets to the flow rate of the primary jet (main jet).

On figa curves C1 and C2 show, respectively, the angle of the solution, depending on the ratio of the flow acting jets / main stream. C1 refers to the configuration of CONF1, in which the acting jets are perpendicular to the main jet and exit at a distance h from the outlet of the main hole, and C2 corresponds to a configuration identical to CONF1, but with a distance of 2 × h instead of h between the secondary holes and the outlet of the main hole. These two curves show that the torch solution is larger when the point of contact of the acting jets and the main jet is closer to the outlet of the main hole.

Fig. 9B shows the changes in the angle of the solution depending on the ratio of the flow rates of the acting jets and the main jet: curve C3 corresponds to the configuration of CONF3 with the acting jets acting on the main jet at an angle of 90 ° (i.e., in the plane perpendicular to the axis of the main jet: θ = 0 °) at a distance of 2 × h from the outlet of the main hole (similar to CONF2), while curve C4 corresponds to the configuration CONF4 identical to the configuration CONF3, except for the inclination angle α of the impact jets, which is 45 °, with respect to the axis of the main page and (i.e., the angle θ between the axis of the impacting jets and a plane perpendicular to the main axis of the jet, = 90 ° -α = 45 °). It is noted that when the impacting jets are perpendicular to the main jet (CONF3: θ = 0 °), all other things being equal, they get a larger torch solution than when the angle of inclination α of the impacting jets is smaller (in this case 45 °) (CONF4: θ = 45 °).

Figure 9 shows the deviation angle (in degrees) depending on the ratio of the flow rate of the impacting jets and the flow rate of the main jet in percentage terms. On figa shows four curves for which, all other things being equal, the flow rate of the main stream, respectively, is 200 l / min, 150 l / min, 100 l / min and 50 l / min. It is noted that these four curves almost coincide, which indicates that the deflection of the flame does not depend on the flow rate of the main jet.

10B shows the heat transfer to the charge: the heat flux generated by the burner in accordance with the present invention, in which the ratio of the flow of the acting jets to the flow of the main jet (shown here as a percentage of the main flow rate) is changed for both the fuel jet and jet of oxidizer (burner with separate injection). Each jet is initially pumped in parallel above the charge and gradually deviates in the direction of the charge, which increases the heat transfer to the charge.

Figure 11 shows the curve of the angle of the torch solution depending on the ratio of the momentum of the jets.

This curve corresponds to the set of experimental data obtained for controlling the solution. The measured angle of the solution is given depending on the physical parameter J, which is the ratio of the specific impulses of the acting jets and the main jet. This ratio is written as the product of the ratio of volumetric masses (the ratio of the acting fluid to the main fluid) and the ratio of the square of the velocity of the acting jets and the square of the speed of the main jet. For all experiments, the same basic fluid was used, while different fluids were used for the impact jets. These fluids are generally distinguished by their bulk density (from the highest to the lowest: CO ₂ , air, air-helium mixture). It is noted that all experimental points (regardless of the applied flow rates and fluids) are aligned in a straight line. This shows that the physical parameter that controls the solution is the above ratio of specific impulses.

Examples

The following examples help to better understand the invention and its use.

Figure 7 shows in more detail a burner with separate injection of different fluids.

The separate injection burner 101 comprises an upper row of nozzles 112 for injecting oxygen in the form of jets and nozzles 125 for injecting natural gas (fuel) in the form of jets, all nozzles being in the refractory mass 121 (FIG. 7C).

The metal (typically) portion 102 of burner 101 is located on the right side of FIG. 7A and is extended by oxygen injection tubes 107 and 109, on the one hand, and natural gas injection tubes 207 and 209, on the other hand, on the left in FIG. 7A.

This figure shows two independent oxygen supply sources 104 and 106 (or any oxidizing agent) supplying chambers 103 and 105, respectively, connected to tubes 109 and 107, respectively, with oxygen passing through tubes 110 and 108.

The end 111 of the tubes is shown in enlarged view in figv, which explains the interaction of the main 108 and acting 110 jets. At the end of the tubes 107 and 109, there is a channel 127 extending the channel 110 for the passage of the acting jet. The wall 109 is continued by the walls 113 having an upward inclination, a horizontal wall 114 and a vertical (in the figure) wall 115, while the central volume 126 allows the channel 127 to be limited, first having an upward inclination, then horizontal and vertical (i.e., forming an angle of 90 ° with respect to to the channel 108 of the gas stream and exiting into it through the hole 120). The vertical part of the channel 127 has a height L defined above and ensures the orthogonality of the jets 110 and 108 at a level of 120 (of course, if you select a junction angle of the jets other than 90 °, the channel 127 will have the required slope and the length L remaining within the limits defined above) . The metal part of the burner ends with a wall 123, in this case a vertical one, passing along the edge of the channel 127, while the metal part is exposed to thermal radiation from the combustion chamber during use. To ensure the long service life of this end of the injection tubes, a protective element can be provided, for example of alumina, which can withstand high temperatures and, for example, is mounted on this metal end to protect it and containing a hole equal to hole 112 (Fig. 7C).

The fuel supply system 204, 206, 203, 205 is similar to the oxidizer supply system described above with the main channel 207, the acting channel 209, restricting the main fuel stream 208 and the affecting fuel stream 210, and everything is in the cylindrical opening 222 of the embrasure 221 (similar to the opening 122 for oxidizing agent). The ends 124 and 125 are similar to 123 and 112. The same injection fuel injection system is provided at the end 207 and 209, as shown in FIG. 7B, with dimensions determined depending on the characteristics of the fuel.

At the same time, it is preferable to have only one jet per nozzle acting on the fluid with the highest momentum (usually an oxidizer in the case of a burner), while the jet thus deflected causes, in turn, the deviation of the other jet outside the burner. In this case, the jet (or a series of jets) with the highest momentum should be located above the jet with a lower momentum so that in the absence of the action of the acting jet on the jet of the highest momentum, the torch produces a torch, mainly directed horizontally, whereas if the acting jet ( acting above and below the main stream with a lot of movement) acts on the main stream, the latter, as mentioned above, is directed downward (gradually, according to the ratio of impulses) and repents for a second stream of smaller pulse (in this case fuel) forming torch which can thus move from a horizontal position to a position inclined in the direction of the heated charge, under the burner flame. Adding an impact jet on either side of the main jet at an angle of 90 ° (or any other angle from 0 ° to 180 °) from said impact jet shown in FIG. 7A (i.e., horizontally at 123 at FIG. 7C, perpendicular to AA), allows the torch to be moved on the heated charge from left to right or from right to left, thus covering essentially the entire surface intended for heating.

According to the invention, the acting jet forms an angle with the main jet that has a value greater than zero. For reasons of size, both channels in which these jets pass are most often fed by a coaxial power system (parallel channels - see Fig. 7).

The invention is illustrated below for the case of a burner designed to heat any charge, which can be a metal charge or any other charge, which must be melted and / or brought to a high temperature, then maintained at this temperature, for example, a charge of ferrous or non-ferrous metal, solid materials for the production of glass, for the production of cement, or, conversely, a mixture that must be drained from the state of a liquid bath.

The invention can, in particular, be used for a tool for processing steel in an electric arc furnace, for example, as follows: as a rule, this type of tool creates a torch (usually subsonic) that allows the metal to heat up, to make it melt, in particular, at the beginning of melting. This torch, as indicated in this application, can change direction due to the effect on each main stream (oxidizing agent, fuel, pre-mixed mixture) or at least one main stream with an acting stream, which causes it to change direction and / or solution so so that this torch can be moved on the charge without the use of complex mechanical means that change the direction of the burner body. These tools are often also equipped with nozzles for the injection of powdered coal, typically injected into the nozzles using a carrier gas. By equipping this nozzle with a secondary jet injection pipe, for example a gas identical to the “carrier gas” of powdered coal, it is possible to change the direction (as well as the spray solution, as for any fluid) of a jet of powdered coal (or atomized liquid fuel) to facilitate a quick meeting jet of sprayed fuel with a torch or, conversely, remove this jet from the torch.

The following examples relate to the control of heat transfer by the burner in accordance with the present invention in the direction of the charge, for example, a metal charge in the process of melting the charge.

An aluminum smelting furnace is typically equipped with one or more burners on one or several side walls surrounding the furnace melting bath located above the metal surface when it is in a completely molten (liquid) state. The torch axis, if horizontal, is at a height of 10 to 100 cm relative to the surface of the metal, preferably 40 to 80 cm.

Example 1. The case of solid material in the furnace

Burners in accordance with the present invention are used to change the inclination of the torch. (Under the slope should be understood as the angle of the torch with respect to the horizontal). If the slope is zero, the torch is directed horizontally. If the slope is not equal to zero, the torch has a slope below the horizontal and is directed to the bottom of the furnace melting bath.

Burners inject each jet of fluid into the furnace chamber, however, this type of burner can only be used for a fluid (oxidizing agent or fuel) of a stronger pulse, when it interacts with a jet of a less powerful pulse to obtain the required flame deflection, usually for fuel in in the case of an air / gaseous fuel or oxygen / gaseous fuel burner.

In the first part of the aluminum smelting cycle, when the metal is mainly in the solid state, the direction of the torch is controlled so that it has a non-zero inclination (torch axis at an angle of 5 ° to 75 °, preferably 25 ° to 45 °). This regulation allows to significantly improve the heat transfer of the burner and, therefore, to reduce the melting time (which was explained with reference to figure 10).

When most metal blocks are molten, the direction of the torch is adjusted so as to obtain a zero angle of inclination. Consequently, the torch is parallel to the surface of the liquid metal. This regulation allows you to continue the transfer of energy to the charge and complete the melting of the metal or to refine it, limiting the heating of the already molten metal and, therefore, its oxidation by a torch or combustion products.

Between the extreme positions of the torch (straight inclination and zero inclination) described above, during the first part of the cycle, intermediate adjustment can also be made in which the inclination of the torch is from 5 ° to 30 °, preferably from 10 ° to 25 °, in order to achieve a compromise between covering the charge furnace torch (the area of the projection of the torch into the bath) and the intensity of heat transfer. On Fig shows the extreme position of the torch with respect to the charge.

On figa shows a top view of an aluminum smelting furnace equipped with two burners in accordance with the present invention, creating two torches located above the metal bath.

The exhaust pipe of the furnace ensures the removal of fumes emitted by torches.

On figv and 12C shows a side view of the same furnace at the level of the torch.

In FIG. 12B, the torch has a slope at an angle α with respect to the horizontal, preferably when solid metal is still present on the metal bath, whereas in FIG. 12C the torch has a zero slope (α = 0).

Between the extreme positions of the torch (straight slope and zero slope) during the first part of the cycle, you can also periodically change the angle of inclination of the torch. For example, the operator can change the slope from 0 ° to 45 °, and then return to 0 °.

Preferably, the burner is controlled by a control unit, which allows to periodically modulate the control ratio, that is, the ratio of the main and acting jets (and), and, therefore, the slope of the torch in the bath. The command signal of the control unit can be sinusoidal, triangular, square, etc. with a variable frequency of 0.05 Hz to 100 Hz, preferably triangular, with a frequency of 0.1 to 10 Hz. A periodic change in the position of the torch allows homogenizing the heat transfer inside the furnace and, thus, melting solid elements faster.

Example 2 Homogenization of heat transfer to the charge

The burners in accordance with the present invention are used so that, as necessary, the torch direction in the horizontal plane can be changed depending on the control ratio of each burner, as shown in FIG. 13.

Each jet of fluid is injected into the furnace chamber through a burner in accordance with the present invention, but for jets located in one horizontal plane or in two horizontal planes located close to each other (at a distance of one to two diameters of the jet), these nozzles can Use only for peripheral jets if they can interact with other deflected jets.

The horizontal direction can be changed in two directions, left and right, either by acting on each main stream with two side acting jets, or by acting on each peripheral main stream with only one acting stream, which can act on the main stream in the horizontal direction, but in two opposite directions each other's sides. You can also shift the axis of the main nozzle in such a way that, with a zero control ratio, the torch naturally deviates (to the right or left) with respect to the axis X-X 'of the burner in Fig. 13, and in this case change the direction of the torch, gradually increasing the control ratio of the system control (that is, receiving a stream along the axis X-X 'with a non-zero control ratio).

The use of one or more burners with an adjustable direction of the torch allows you to increase the coverage of the charge by moving the torch in a horizontal plane.

(The expression “control ratio” used above is defined as the ratio of the flow rates of the acting jet and the main jet, given that the momentum of the fluid jet can be controlled by simply changing the degree of opening of the valve, while, all other things being equal, increasing the degree of opening of the valve is proportional to the increase in flow rate )

If the burner control ratios (lok) are equal to zero, the direction of the torch is in the natural axis of the burner, and the torch covers the portion of the charge. When the control ratio is not equal to zero, the position of the torch deviates, and the torch covers another portion of the charge.

On Fig shows an example of horizontal movement of the torch above the charge; each main stream 130, 132 (oxidizing agent or fuel) corresponds to the acting stream 131, 133; 13A, the control ratio CR of the jet 130 is zero, that is, no fluid is injected into the channel 131; the CR control ratio of the jet 132 is positive, which means that since 133 acts from the bottom up in FIG. 13A, the impact jet 133 deflects the main jet 132 up in the figure, that is, to the left with respect to the axis X-X ′ of the burner.

13B, since the control ratios of the two main jets 130 and 132 are equal to zero (CR = 0), the action of the impact jets is absent, and the torch propagates along the axis X-X '.

On figs, in contrast to figa, the CR control ratio of the jet 130 and 132 is positive, which leads to the deflection of the torch down in the figure (to the right, when viewed from above), while the main jet 132 and the impact jet 133 have a zero ratio control (jet 133 is absent).

Thus, each burner can process a larger portion of the charge, facilitating the homogenization of heat transfer and allowing to limit the possible formation of hot spots if there are refractory materials in the bath (for example, residues containing alumina recycled or formed during the oxidation of the molten metal), and, in general, contributing to heat transfer, allowing to accelerate the melting process with constant power or reduce energy consumption at a constant melting time.

Example 3 torch with a variable inclination to the charge, processing the charge from the side

Example 4 Closed loop control

This embodiment of the invention makes it possible to control both horizontal and vertical movement of the torch depending, for example, on the operating parameters of the furnace, measured by various sensors installed on the furnace, and, in particular, sensors of heat flow, temperature or, if necessary, chemical composition (for example laser diode type TDL).

- A control loop, the sensor of which is a measurement device that allows you to get an image of heat transfer to the charge or oxidation of the aluminum bath, while this information allows you to reduce or increase the heat transfer to the charge by affecting the flow rate of the acting jet, as described above.

- The contour of the regulation of the position of the torch, based on the measurement of the temperature of the bath when at least part of the bath is in a solid state. While the temperature of the bath is less than the value of Tc, which is in the range from 650 to 750 ° C, for example, for aluminum, the torch should remain with a non-zero slope in the bath to ensure maximum heat transfer. When approaching the value of Tc, the torch is gradually raised, taking it away from the bath, and removed as much as possible when the specified value is reached, in order to limit the possibility of oxidation of the charge. After that, the slope of the torch is adjusted so as to maintain the temperature at a predetermined value.

- Flame control loop based on heat flow measurement:

This heat flux can be estimated through the temperature difference, measured between two thermocouples immersed in the bath at two different depths, but on the same generatrix, perpendicular to the bottom of the furnace.

The heat flux can also be determined on the basis of the calculated values of the heat transfer through the furnace, again by measuring the temperature difference inside the furnace. Given the higher heat resistance of the hearth made of refractory materials, a significant temperature gradient can easily be obtained.

The heat flux can also be monitored using a heat flux meter mounted, for example, on the roof of the melting chamber. Indeed, ceteris paribus, any decrease in flow sensed by the arch and monitored by the heat flow meter corresponds, at least in part, to an increase in the heat flow transferred to the charge. (In this case, the absolute value of the heat flux transferred to the charge (or the loss on the walls) is of less interest than the time variation of the corresponding signal).

Melting of the charge begins with the torch with a direct slope towards the charge, and this slope is maintained, while the flow transmitted to the charge remains large. As soon as this flow decreases, which corresponds to an increase in the temperature of the charge and a decrease in its ability to heat absorption, the torch is gradually raised, removing it from the bath, in order to limit the possibility of oxidation or overheating of the charge.

- Flame control loop based on measuring the composition of the fumes at the furnace outlet or inside the furnace, for example, in front of the furnace smoke collector, above the bath, between an inclined torch and an aluminum bath, etc., to detect one or more substances that indicate oxidation aluminum bathtubs such as CO:

but. The composition of the fumes can be measured in a known manner by selection followed by analysis (classical analyzers, TDL or others), or in situ by the adsorption method (laser diode or other device), or using an electrochemical probe.

b. Melting starts with a torch with a direct slope on the charge, and this slope is maintained until the oxidation index or indicators remain stable and in small quantities. As soon as the concentration of the indicator or indicators increases, the torch is gradually raised, moving it away from the bath, in order to limit the concentration of the indicator or indicators and, therefore, the oxidation of the charge, acting on the main stream using the acting stream, as described above.

from. In addition, the position of the torch can be adjusted to achieve a predetermined value, and then maintain the exact predetermined concentration value of the oxidation index. Indeed, one can fix the concentration threshold, which should not be exceeded, and constantly adjust the slope of the torch for this purpose.

It should be noted that in all cases, if the charge consists, at least partially, of a cold solid, the torch can be sent directly to the charge, since as long as the temperature remains moderate, for example, less than 600 ° C for aluminum, the oxidation state remains low . When the charge becomes substantially liquid, control is applied to avoid an increase in the temperature of the metal and its oxidation. In the case of using the invention for heating material other than aluminum, for example for heating bath glass, etc., the same principles apply for temperatures and criteria that differ from one material to another, but the principles themselves remain the same and well known to specialists.

Example 5 Emission control

All primary technologies for reducing nitrogen oxide emissions in industrial burners or furnaces use local properties of fluid or torch flows to limit their formation. In particular, their goal is to reduce the temperature or concentration of the reactants (fuel, oxygen) or to reduce the residence time of the reactants in the flare and / or in the combustion products. One of these technologies is the injection of a sufficient amount of gaseous products of combustion into the reactants or into the flare to lower the temperature, the concentration of the reactants or to reduce the residence time. To do this, the dimensions of the burner are chosen so as to obtain a jet of fuel and / or oxidizer at a high speed (strong pulse) and sufficiently remote to obtain the maximum degree of supply or recirculation of gaseous products of combustion, compatible with normal stabilization of the flame. The stabilization limit is detected when unburned substances appear in the products of combustion, such as carbon monoxide in the case of hydrocarbons. In some conditions, it is possible to obtain a “no flame” combustion mode that exclusively contributes to the reduction of emissions.

A limitation of this technology or these combustion technologies is that the degree of involvement of the gaseous products of combustion is determined by the size of the burner and the operating conditions. Consequently, the characteristics regarding these emissions can significantly deteriorate when deviating from these conditions, as well as when changing fuel or when the own flows of the furnace or furnace are largely involved in the properties of flares.

The invention allows to adapt during operation the properties of flares and, in particular, the degree of recirculation of gaseous products of combustion, which in any case allows to minimize emissions of pollutants and, ultimately, to optimize the performance of the burners.

Example 6 Pre-mixed burner containing nozzle located in the furnace

The acting jets described above are used to change the angle of solution of the main jet of fluid (or several jets) during operation. In this case, the main jet is a pre-obtained gas mixture of fuel and oxidizer. The jet solution determines the level of entrainment of the environment by it, and it can be measured by the angle between the axis of the jet and the tangent to the boundary between the jet and the environment. (This boundary can be defined as the place in the jet where the concentration of the injected fluid becomes zero).

The jet solution is controlled by the ratio between the flow rate of the acting jet and the total flow rate of the resulting jet. When this control ratio is zero, the emission level N1 is measured (FIG. 15). In essence, this control ratio is the ratio of pulses, which was explained above.

After that, the control parameter is increased in such a way as to increase the involvement of gaseous products of combustion in the stream and to dilute, thus, the injected combustible mixture. This dilution leads, on the one hand, to a decrease in temperature and, on the other hand, to the concentration of reagents in the flare. Thus, NOx emissions are reduced to N2 (FIG. 15). If you continue to reduce the value of the control parameter, the temperature and concentration of the reagents become too low to ensure good stabilization of the flame: unburnt substances appear in the combustion products. In this case, nitrogen oxides are at the level of N3, and emissions of unburnt substances are at a too high level of l3. Therefore, the control parameter is reduced to obtain the optimal level of emissions N0 and 10 (the intersection of the curves of NOx and unburned substances in Fig.15). This optimum can be obtained manually (passive control) or preferably using an active control device. This device contains sensors for measuring emissions of nitrogen oxides and unburned substances, an automatic machine using the control logic described above, and control elements for the flow rate of the main stream and the current stream (s) of at least one nozzle thereof. The machine determines the value of the control parameter, which minimizes emissions of nitrogen oxides and unburned substances. Active control becomes necessary when the number of optimized parameters is more than two or equal to two. For example, it is possible to simultaneously minimize pollutant emissions by increasing the degree of dilution of the flame by the gaseous products of combustion and to maximize the heat transfer to the charge by tilting the flame in the direction of the charge.

Example 7 Burner without premixing

If combustion technology is used without prior mixing, then control can be performed both on fuel and on an oxidizing agent, as well as on both, as in example 5.

If necessary, you can combine the effects of the solution (environmental involvement) and the deviation of the jets (diverging jets of fuel and oxidizer), in particular with the aim of increasing the effect of dilution of the torch and the maximum reduction of emissions.

Claims (22)

1. A burner containing:
- a channel for supplying a primary stream of oxidizer, or fuel, or a pre-obtained mixture of oxidizer - fuel to the main outlet,
at least one secondary conduit for injecting a secondary jet, in which:
- said at least one secondary conduit enters the channel through the secondary hole in front of the main hole and is located relative to the channel so that at the point of interaction between the corresponding secondary stream and the primary stream, the angle θ between the axis of the corresponding secondary stream and a plane perpendicular to the axis the primary stream was greater than or equal to 0 ° and was less than 90 °, preferably ranged from 0 to 80 °, even more preferably from 0 to 45 °, and
- said at least one secondary hole is spaced from the main hole by a distance L less than or equal to ten times the square root of the cross section s of the main hole, preferably L≤5 · √ s, even more preferably L≤3 · √ s,
characterized in that:
- the burner contains means for regulating the momentum of each respective secondary stream,
wherein said burner allows you to change the direction and / or solution of the torch by changing the momentum of at least one corresponding secondary stream. 2. The burner according to claim 1, in which the means of regulation control the ratio between the pulse of each respective secondary stream and the pulse of the primary stream. 3. The burner according to one of the preceding paragraphs, containing at least one secondary pipeline located relative to the channel so that at the level of the corresponding secondary hole the axis of the primary jet and the said secondary jet intersect or almost intersect, which allows you to change the angle of the torch at the exit burners with respect to the axis of the primary jet in front of the corresponding secondary hole. 4. The burner according to claim 3, containing at least two secondary pipelines located relative to the channel so that the two corresponding secondary holes are in the same plane perpendicular to the axis of the primary jet, while at the level of these two corresponding secondary holes the axis of the corresponding secondary jets intersect or nearly intersect with the axis of the primary fluid stream. 5. The burner according to claim 4, in which two respective secondary holes are coplanar with the axis of the primary jet at the level of two secondary holes and are located on both sides of this axis of the primary jet. 6. The burner according to claim 4, in which the plane formed by the axis of the primary stream at the level of two corresponding secondary holes and one of the two corresponding secondary holes is perpendicular to the plane formed by the axis of the primary stream and the other of two corresponding secondary holes. 7. The burner according to one of claims 4 to 6, containing at least four secondary pipelines located in relation to the channel so that the four corresponding secondary holes are in the same plane perpendicular to the axis of the primary jet, and at the level of these four secondary holes the axes of the respective secondary jets intersect or almost intersect with the axis of the primary jet, while two of these respective secondary holes are coplanar with the axis of the primary jet in the first plane and are located on both Torons from this axis, and two other respective secondary openings are coplanar with the primary jet axis in a second plane and are located on either side of this axis. 8. The burner according to claim 1, in which at least one secondary conduit is located relative to the channel so that at the level of the corresponding secondary opening, the axis of the corresponding secondary stream of fluid is not essentially coplanar with the axis of the primary stream of fluid, which allows you to create, maintain or enhance the rotation of the resulting stream of fluid around its axis, as well as change the torch solution at the outlet of the burner. 9. The burner of claim 8, containing at least two secondary piping located in relation to the channel so that the axes of the respective secondary jets are not essentially coplanar with the axis of the primary jet, and the corresponding secondary jets are oriented in one direction of rotation around the axis of the primary jet. 10. The burner according to claim 9, in which two corresponding secondary holes are located on both sides of the axis of the primary jet. 11. The burner according to claim 1, in which at least one secondary pipe is located relative to the channel so that at the level of the corresponding secondary hole the secondary pipe has a thickness e and a height l, while the height l is greater than or equal to 0.5 thickness e preferably ranges from 0.5 e to 5 e. 12. The burner according to claim 3, in which at least one secondary pipe is located relative to the channel so that at the level of the corresponding secondary hole the secondary pipe has a thickness e and a height l, while the height l is greater than or equal to 0.5 thickness e preferably ranges from 0.5 e to 5 e. 13. The burner according to item 12, containing means for controlling the ratio of the pulses of the main stream of fluid and the secondary stream of fluid. 14. The burner according to claim 1, containing a block of material in which at least part of the channel is located, the main hole being located on one of the sides or surfaces of the block. 15. The burner according to claim 1, containing means for controlling the pulses of the primary and / or secondary jets. 16. The burner according to claim 1, containing an embrasure located at the end of the channel, and at least one secondary hole extending into the channel through a secondary hole located in the embrasure. 17. A method of heating a charge using a torch, wherein said torch is obtained by means of a burner according to one of the preceding paragraphs. 18. The method according to 17, in which the direction and / or solution of the torch is changed due to the interaction of the primary jet with at least one secondary jet. 19. The method according to p, in which the primary stream is a stream containing an oxidizing agent, or fuel, or a pre-obtained mixture of an oxidizing agent and fuel. 20. The method according to one of paragraphs.17-19, in which the direction of the torch for processing by scanning at least part of the surface of the charge. 21. The method according to claim 20, in which the direction of the torch is changed in at least two intersecting planes for processing by scanning at least part of the surface of the charge. 22. The method according to 17, in which in the first phase the torch is directed towards the charge and in the second phase the torch is directed essentially parallel to the charge.

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