EP2564119B1 - Multi-flame burner with flame transmission - Google Patents

Description

The present invention relates to a multi-flame burner with Brenngasbeaufschlagbaren burner nozzles, in particular for thermal material processing methods, a Brenngasbeaufschlagbare burner nozzle of such a multi-flame burner, and a method for thermal material processing, in which such a multi-flame burner is used.

State of the art

Although the present invention will be described below with reference to certain thermal material processing methods, it should be emphasized that multi-flame burners according to the invention, as well as the corresponding burner nozzles, can also be advantageously used in other fields of application. For example, the present invention can be used for flame brazing, fusion bonding, for example, flame spray coating, hot forming, and flame hardening. This may also be in particular methods for preheating, reheating, soaking and hot forming, for example in mechanical engineering, steel and container construction, act. Also, for example, for drying, especially for drying before sandblasting, welding or signing, the invention can be used.

For example, flame heating according to DIN 8522 is a process in which a workpiece is heated to change its properties, such as to affect the resistance to deformation.

Flame heating is also used for preheating in welding, cutting and related metalworking processes. For example, in flame cutting, sheets of more than 30 mm thickness made of S355 steel are preheated to 89 to 128 ° C immediately before cutting. For carbon steels, temperatures of up to 200 ° C are used in welding processes and temperatures between 100 and 400 ° C for alloyed steels.

In flame blasting, for example with acetylene, a burner nozzle assembly is directed onto a workpiece surface. As a result, clean sheet surfaces for further processing can be achieved and remove rust, mill scale and scale layers easily and inexpensively. In addition to metal, flame spraying can be used to thermally treat concrete and natural stone surfaces in order, for example, to remove paints, coatings, oil spills or rubber abrasion and to create surfaces.

Acetylene burners are often used in the applications presented. Compared to other fuel gases, acetylene has an extremely high flame temperature of more than 3,000 ° C., which can be attributed inter alia to the positive formation enthalpy of the acetylene molecule (C ₂ H ₂ ). Per kilogram of acetylene 8,714 kJ are released for thermal utilization. These properties of acetylene are therefore of particular interest in thermal heat processes, since the heat is all the faster the flame passes to the workpiece, the higher the temperature of the combustion flame. Other advantages of acetylene include the high ignition speed. The thermal efficiency is better in the said method, the faster the hot combustion products impinge on the workpiece. This requirement arises in particular when heating metallic materials with high heat dissipation, for example in steel, copper and aluminum.

In the context of the methods mentioned, multi-flame burners are frequently used, that is to say burner arrangements which have burner nozzles (individual nozzles) which are supplied by a common fuel gas source. In the FIGS. 1A to 1C Such multi-flame burners are shown. Figure 1A shows a standard hand torch, in FIG. 1B is a so-called ingot burner and in Figure 1C a lance burner shown. The illustrated burners have as common features a fuel gas supply 1, via which, for example, a gas mixture of acetylene and oxygen is supplied. At a Gasführungs- and holding device or a burner body 2 burner nozzles 3 are attached. By igniting the burner nozzles 3 in the case of fuel gas flowing out, working flames 4 are formed. The burner nozzles may have regulating and / or adjusting devices 5. Another Mehrflammenbrennen according to the preamble of claim 1 discloses the DE 18 15 004 A1 ,

Before using a suitable burner, all individual nozzles, for example with pilot lights or spark plugs, must be ignited manually or automatically. During manual ignition of the burner, for example, a pilot flame is guided along the burner nozzles or it is ensured by means of a dynamic pressure that a flame is formed at all burner nozzles. For example, the burner is close to a correspondingly large plate hold. The operator of a corresponding facility has to ensure that a flame is formed at all burner nozzles (the mixture outlet points). While manual ignition of a visual inspection of the ignition process is possible, this option is not always given in the automated operation of a corresponding burner, which usually also an automatic ignition takes place. In automated burner operation, the so-called "burning through" of all flames often causes difficulties. For example, if the torch is not aligned with a workpiece or the geometry of the workpiece is inappropriate or the distance between the torch nozzles is too great, the tendency to bleed will be degraded.

For the purposes of this application, the term "flashover" is understood to mean the passing on of a pilot flame or burner flame from one burner nozzle to the next. The other burner nozzles then ignite successively at the first burner nozzle, so they ignite.

If the ignition is unsuccessful, unburned fuel gases can escape. If no additional safety precautions are taken, fuel gases accumulate in the vicinity of the burner and there is a danger of explosion.

Against this background, there is a need for multi-flame burners with improved transmission properties.

Disclosure of the invention

The invention proposes a multi-flame burner with Brenngasbeaufschlagbaren burner nozzles, in particular for thermal material processing methods, a brenngasbeaufschlagbare Burner nozzle for such a multi-flame burner, and a method for thermal material processing with the features of the respective independent claims before.

Preferred embodiments are the subject of the respective subclaims and the following description.

For the purposes of this application, the term "fuel gas" means pure fuel gases, for example acetylene, methane, ethane, propane, butane, ethene, methylacetylene or hydrogen, but also any suitable gas mixtures and also mixtures containing oxygen and fuel gas, such as fuel gas. Oxygen / compressed air / suction air mixtures, understood.

According to the invention, at least one of the burner nozzles of a multi-flame burner has two, three or more auxiliary nozzle openings arranged linearly laterally of a main nozzle arrangement for generating a working flame. The secondary nozzle opening is traversed by the same fuel gas as the main nozzle opening and is advantageously in fluid communication with this and a fuel gas supply.

By providing and a suitable arrangement of at least one auxiliary nozzle opening occurs after ignition to form at least one secondary flame, the orientation of which has a direction component (vector component) in the direction of the adjacent combustion nozzle, which is thus suitably aligned in the direction of a working or secondary flame of an adjacent burner nozzle , Through the measures according to the invention, the passing of a flame between individual burner nozzles of a Multi-flame burner can be significantly improved. In this way, a complete ignition of all the flames of a multi-flame burner can be achieved safely and reliably, provided that the burner head distance and the fuel gas quantity and / or composition (for example, an acetylene burner) are in the functional range. The measures according to the invention no longer require that the burner be aligned directly with a workpiece. The risk of escape of unburnt fuel gases due to non-combusted burner and the resulting risk of explosion is reduced or eliminated.

In the context of this application, the term "working flame" is understood to mean the respective main flame of a burner nozzle of a multi-flame burner, which is directed onto a workpiece and serves, for example, for heating this workpiece. The working flame is usually generated either by a single nozzle, or by a main nozzle assembly in which a central nozzle is surrounded by annularly arranged around these other nozzles. If, instead of a main nozzle arrangement, a single nozzle is provided, this is included in the scope of the application by the term "main nozzle arrangement".

Correspondingly, an "auxiliary flame" is the flame provided according to the invention, caused by the provision of at least two auxiliary nozzle openings, and at least partially aligned with an adjacent nozzle. Typically, the sub-flames are smaller than the main flames due to lower gas volumes flowing through the sub-nozzle openings.

It is understood that in practice the area of a "flame" will not be clearly demarcated, so that a "working flame" and an "auxiliary flame" may also be flame areas of a corresponding overall flame. Typically, however, the primary flames, which are respectively generated at the main and secondary nozzle openings, for example an acetylene fuel nozzle, are at least partially visually distinct from each other. The so-called scattered flame forming around a primary flame usually envelops the primary flame in the form of an overall flame.

In order to form secondary flames in the direction of the at least one adjacent burner nozzles, at least two auxiliary nozzle openings and / or at least one nozzle channel assigned to a corresponding auxiliary nozzle opening can be arranged at an angle to the main nozzle arrangement and / or a nozzle channel associated therewith.

With particular advantage, in particular with an arrangement of a plurality of burner nozzles in a multi-flame burner in series or in a burner field, at least one of the burner nozzles is provided with auxiliary nozzle openings for generating secondary flames in the direction of at least two adjacent burner nozzles. By virtue of this arrangement, a secondary jet opening through which fuel gas flows can, after being ignited, pass on a flame directly to an adjacent, not yet ignited, but fuel gas flow-through secondary jet opening. As a result, the adjacent burner nozzle is ignited altogether and, in turn, due to the arrangement of the auxiliary nozzle openings, can pass on the flame to at least one further burner nozzle, thus igniting a burner arrangement.

In order to achieve a particularly effective design of the secondary flames with an advantageous geometry, a multi-flame burner of the type according to the invention has two, three or more secondary nozzle openings on at least one side of the main nozzle arrangement. By means of a corresponding arrangement, overall a suitable configuration or cross-sectional geometry of a burner flame and corresponding secondary flames can be effected. Such a cross-sectional geometry can be adjusted selectively, for example based on a distance between individual burners and / or the type or pressure of a used fuel gas, so that a particularly effective transfer of burner flames is made possible.

As explained, a multi-flame burner according to the invention is set up such that at least one of the burners serves to ignite at least one adjacent burner nozzle via at least two secondary flames. This can be achieved for example by suitable alignment of the auxiliary nozzle openings, their geometry, but also by suitable spacing of the burner nozzles. Due to the special design of the burner nozzles with sub-flames, it is only necessary for igniting a burner arrangement to ignite a burner, for example automatically, in one place, wherein a secure ignition of the entire burner is ensured.

A multi-flame burner according to the invention is designed as a hand torch or machine torch, for example as a strip burner or lance burner, for operation with acetylene as the fuel gas. In particular, lance and inguinal burner with linear Burner arrangement profit due to their tendency to tend to Durchzündneigung especially of the measures according to the invention.

A multi-flame burner of the type described has at least one burner nozzle, a manual ignition device, a pilot flame, a spark plug or a piezo igniter for ignition, whereby the multi-flame burner is particularly suitable for automatic applications with non-manual ignition.

For the features and advantages of the present invention also provided Brenngasbeaufschlagbaren burner nozzle is expressly made to the features of the previously explained multi-flame burner. In particular, such Brenngasbeaufschlagbare burner nozzle is formed interchangeable, so that can be exchanged individual nozzles combine in a burner body to form a multi-flame burner and thereby the flame propagation can be optimized. Also to the advantages and advantageous areas of application of the method according to the invention is made to the previously described features.

Further advantages and embodiments of the invention will become apparent from the description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

The invention is illustrated schematically with reference to an embodiment in the drawing and will be described in detail below with reference to the drawing.

figure description

FIG. 1

shows multi-flame burner according to the prior art in a schematic representation.

FIG. 2

shows a burner nozzle according to an embodiment of the invention in perspective perspective perspective view.

FIG. 3

shows a burner nozzle assembly according to an embodiment of the invention according to the invention in plan view from above.

FIG. 4

schematically shows an arrangement in operation burner nozzles according to an embodiment of the invention in side view.

The FIGS. 1A to 1C show, as explained above, multi-flame burner according to the prior art.

In the following figures, the same or equivalent elements are provided with identical reference numerals. A repeated explanation of these elements is omitted for clarity.

FIG. 2 shows, denoted overall by 10, a burner nozzle according to an embodiment of the invention Invention, which can be used for example in a multi-flame burner according to the invention.

The burner nozzle 10 has a burner nozzle head 20 and a burner nozzle foot 21. If the burner nozzle 10 is an exchangeable nozzle, it can be fastened to the burner nozzle foot 21 in a burner base body. In the burner nozzle head 20, a main nozzle assembly 30 is provided, which has a main nozzle opening and this circularly surrounding further nozzle openings. The main nozzle assembly 30 is, as previously explained, configured to form a working flame.

In addition, the burner nozzle 10 for generating secondary flames in addition to the main nozzle assembly 30 provided on the auxiliary nozzle openings 40. The auxiliary nozzle openings 40 themselves, or their corresponding nozzle channels, can be offset angularly from the orientation of the main nozzle arrangement 30, so that a targeted alignment of the secondary flames in the direction of adjacent burner nozzles or their flames can be achieved.

In FIG. 3 a total of 4 burner nozzles 11, 12, 13 and 14 are shown according to a particularly preferred embodiment of the invention in plan view.

The burner nozzles 11, 13 and 14 correspond to the burner nozzle 10 in the configuration and arrangement of the auxiliary nozzle openings 40 FIG. 2 , The burner nozzle 12, however, has further, in the figure vertically downwardly facing auxiliary nozzle openings 41, which are aligned in the direction of a right angle to the row of burner nozzles 11, 12 and 13 arranged burner nozzle 14. By the arrangement, how you in FIG. 3 is illustrated with particular advantage, a flame-through or a flame propagation, as illustrated by the arrows 50, between the individual burner nozzles 11, 12, 13 and 14, achieve. The illustrated burner nozzles 11, 12, 13 and 14 may be part of a multi-flame burner or a burner field of a multi-flame burner. It is understood that the configuration shown in Figure 3 is arbitrarily expandable and when providing additional auxiliary nozzle openings 40, 41 and a secure ignition ignition 50 can be effected in additional directions.

In FIG. 4 a corresponding burner nozzle assembly is shown schematically in operation. A fuel gas passes out of the burners 15 via a main nozzle arrangement and side-nozzle openings 40 arranged laterally therefrom. This results in the formation of a main flame or working flame 60, which can be aligned with a workpiece. The primary flame of this working flame is indicated at 70. In addition to the main flame 60 and the primary flame 70 are in the FIG. 4 Sub-flames 80 shown with corresponding primary flames 90. The secondary flames 80 are at least partially aligned in the direction of adjacent nozzles, resulting in said particularly advantageous ignition.

Claims (8)

1. Multi-flame burner with burner nozzles (10 - 15) subjectable to fuel gas, in particular for thermal material-processing methods, the multi-flame burner being designed as a hand burner or machine burner, for example as a strip burner or lance burner, so as to be suitable for operation with acetylene as fuel gas, and at least one of the burner nozzles (10 - 15) being provided with at least one secondary nozzle orifice (40), arranged laterally with respect to a main nozzle arrangement (30) for generating a working flame (60), for the purpose of generating a secondary flame (80), the orientation of which has a direction component directed towards an adjacent burner nozzle (10 - 15), characterized in that at least one of the burner nozzles (10 - 15) is provided with two, three or more linearly arranged secondary nozzle orifices (40) on at least one side of the main nozzle arrangement (30).
2. Multi-flame burner according to Claim 1, characterized in that at least one secondary nozzle orifice (40) and/or at least one nozzle duct assigned to a secondary nozzle orifice (40) are/is arranged at an angle to the main nozzle arrangement (30) and/or to a nozzle duct assigned to the main nozzle arrangement (30).
3. Multi-flame burner according to Claim 1 or 2, characterized in that at least one of the burner nozzles (10 - 15) is provided with secondary nozzle orifices (40) for generating secondary flames (80) in the direction of at least two adjacent burner nozzles (10 - 15).
4. Multi-flame burner according to one of the preceding claims, characterized in that at least one of the burner nozzles (10 - 15) is designed for igniting (50) an adjacent burner nozzle (10 - 15) via at least one secondary flame (80).
5. Multi-flame burner according to one of the preceding claims, which is designed for igniting at least one burner nozzle (10 - 15) by means of a manual ignition device, an ignition flame, a spark plug and/or a piezo-ignitor.
6. Burner nozzle subjectable to fuel gas for a multi-flame burner according to one of Claims 1 to 5.
7. Thermal material-processing method, in which a multi-flame burner according to one of Claims 1 to 5 is used, at least one burner nozzle (10 - 15) being ignited by means of a secondary flame (80) of an adjacent burner nozzle (10 - 15).
8. Thermal material-processing method according to Claim 7, which comprises at least one torchsoldering, fusion-welding, hot-working, flamehardening, scarfing, preheating, reheating, soaking, drying and/or hot-forming step.

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