EP1557636A1 - Safety ignition device for flame generator used for a spectacle - Google Patents

Abstract

The generator or projector has an ignition system comprising converters supplying two electrodes to generate electric arc between the electrodes that are spaced from each other. The system simultaneously generates another electric arc at the side of the former electric arc during the emission of a spray obtained from liquid hydrocarbon. Each electric arc is supplied independently by its own converter. An independent claim is also included for utilization of a flame generator or projector for the production of flames of large length for a show.

Description

The present invention relates to an improvement to the generators of flames by ignition of fuels, in particular for pyrotechnic and / or aquatic shows or the realization of special effects.

More particularly, the subject of the present invention is a secure ignition device for a flame generator for the show, which allows the ignition of liquid fuels, in particular hydrocarbons, whatever the conditions of "fire" of the flames, and especially for the production of flames under very wet, and sometimes even after immersion of the flame generator.

The technical field of the invention is that of the production pyrotechnic effects and shows, as well as the design of devices for achieving such effects.

Currently, there are, especially in amusement parks and other places where regularly or occasionally shows, a very important demand for performing shows complex pyrotechnics, if any combined with effects requiring the creation of flames on the surface of the water or associated with projections of water jets.

We know, to date, different systems for producing flames but these systems are not totally satisfactory, especially on the plan of the reliability of the devices of ignition of the flames.

In particular, flame generators are known which use arc ignition devices produced between two electrodes connected to a high-voltage transformer, said electric arc igniting a jet of hydrocarbon sprayed by known means of nozzle type or other.

These ignition devices have a material constitution unsuitable for repeated uses, with assembly and regular disassembly to adapt the flame generators to different configurations of shows. Similarly, in case of storage of flame generators in wet environments, losses may occur power supply at the level of the ignition devices due to electrode insulation failures that may render the electrodes out of order transformers supplying said electrodes.

These arc ignition devices present the disadvantage of being very sensitive to certain operating conditions. In particular, the main disadvantage is that the distance adjustment spacing of the electrodes for producing the electric arc is very easily modified accidentally during editing operations and disassembly of the flame generators, during preparation and after the performance of shows. These accidental changes of spacing electrodes results in impaired device performance electric arc ignition. In addition, the wear of the electrodes can also change the setting of the distance between the electrodes and influence the good operation of the ignition system.

Moreover, under conditions of high humidity, for example during the production of pyrotechnic shows on the water, it can be produce short circuits that can destroy the circuit electric firing. In addition, static drops of water can form around one or both electrodes and form an insulator prevents the electric arc from forming between these electrodes.

The present invention aims to provide a secure ignition device for a flame generator for the show, which can electrode adjustment problems encountered with known devices and which moreover can be used for the realization of flames with a very good ignition reliability and safely without risk of deterioration of the equipment or malfunction of the generators of equipped flames.

The present invention achieves these goals by an ignition device secure for a flame generator for the show featuring at less a fuel projection means, said ignition device a pair of electrodes connected to at least one means power supply for generating at least a first electric arc adapted to ignite a jet of fuel projected by said means of projection close to said electrodes, characterized in that said ignition device comprises at least a second pair of electrodes connected to the said average (s) power supply and able to generate at least a second electric arc, simultaneously or not at the said first electric arc, to ignite said fuel jet, said electrode pairs being mounted on a chassis and further connected to watertight manner (s) said means (s) power supply.

Preferably, said pairs of electrodes are fixed on a said chassis in the vicinity of said fuel projection means, for example a nozzle, itself preferably fixed to said frame.

Such an ignition device makes it possible to disadvantages encountered with generators equipped with devices electric ignition systems, and this by the simple addition of a second pair of electrodes, preferably identical to the first pair. This second pair of electrodes ensures the formation and presence of at least one electric arc when projecting the jet of fuel to ignite it and despite a possible imbalance chance of the difference between the electrodes, the probability of disturbance and / or of simultaneous malfunction of the two pairs of electrodes being quasi null in practice. The ignition device of the flame generator is thus secured against flame ignition failures.

In an advantageous embodiment, the two said pairs electrodes of said ignition device are connected to the same means power supply.

In this configuration, a compact ignition device is provided capable of perfectly simultaneous production of at least two arcs electrical devices to ignite a fuel jet at the time of its projection by a jet.

In another advantageous embodiment, the device ignition circuit comprises at least two said power supply means able to supply respectively the at least two said pairs electrodes independently of one another so as to guarantee the the presence of at least one arc at the moment of the emission of said jet of combustible.

In this configuration, the ignition device according to the invention is still secure to the extent that one prevents, through a diet independent of each pair of electrodes, the risks of malfunctions of a single power supply, such as short circuits, which could prevent the formation of an electric arc between electrodes.

Thus, even if the feeding means of one of said pairs of electrodes is out of service at the time of the emission of the jet of combustible, an electric arc can still be generated between electrodes of the second pair connected to a non-feed means failed. Here too, the electrodes such as the feeding means being checked regularly, or even before each show, the probability of simultaneous malfunction of the supply means of each pair electrodes of the ignition device is very small.

Advantageously, each said electrode comprises a tip tungsten conductor and the distance between the ends of the tips conductive two said electrodes of at least one pair of electrodes is between 0.5 to 1.5 cm, said ends of the tips said electrodes converging preferably towards the projection axis said projection means.

The respect of such a spacing between the ends of the tips of the electrodes is important because this gap determines the possibility of training an electric arc between two electrodes. In addition, the convergence of ends in the direction of the axis of the projection means (in practice the axis central jet of a fuel projection nozzle) ensures the producing an electric arc closest to said jet during the emission of it, and preferably at the periphery of said jet to ignite this last despite the pressure, often important, of spraying the fuel at the jet nozzle of a flame generator.

In another preferred embodiment, said electrodes of said ignition device are equidistant from the axis of said projection means.

Said electrodes may in particular delimit a "rectangle" or a "square" of which they occupy the angles, the axis of said projection means passing through the center of said square or rectangle, said ends of points of said electrodes being directed or converging towards this center and preferably spaced at most 1.5 cm apart.

An arrangement of rectangle electrodes around the nozzle greatly reduces the risk of generator malfunction flames by default of producing an electric arc at the time of the emission of a fuel jet, and especially when each said pair of electrodes is powered independently. Indeed, with a such electrode configuration, the jet of fuel emitted by the jet necessarily passes in front of at least one electric arc formed between conductive tips of two electrodes, an electric arc that can be form between two electrodes of the same pair or between two adjacent or opposite electrodes of each pair, the arc always forming between the points of two closest electrodes.

To further facilitate arcing and tuning of the electrode gap, said ends of the conductive tips said electrodes are preferably bent at right angles to the of said projection axis of the projection means relative to said electrodes, these being preferably parallel to said projection axis.

• la figure 1 représente, en vue de dessus, l'unité d'allumage d'un générateur de flammes pour le spectacle équipé du dispositif d'allumage sécurisé selon l'invention dans un mode de réalisation préféré;
• la figure 2 représente une vue de côté de l'unité d'allumage du générateur de flammes de la figure 1.

The constitution and operation of the secure ignition device according to the invention will emerge more clearly from the following detailed description of the invention, with reference to the appended figures in which:

• Figure 1 shows, in top view, the ignition unit of a flame generator for the show equipped with the secure ignition device according to the invention in a preferred embodiment;
• FIG. 2 is a side view of the ignition unit of the flame generator of FIG.

With reference to FIGS. 1 and 2, the flame generator 1 comprises a housing 2 constituting a support frame on which on and in which is installed the ignition device 3 by electric arc according to the invention.

A nozzle 4 connected to a fuel tank by a network of fuel distribution not shown in Figure 1 is fixed in said housing 2 for projecting a fuel in the form of a micronized jet under strong pressure to produce a flame.

The fuel used for the production of flames with the generator 1 is preferably a liquid fuel such as hydrocarbon. The hydrocarbons used can be of any known type in the production of pyrotechnic shows.

However, it is preferred to use with the device of the invention, a liquid isoparaffinic hydrocarbon having a flash point greater than 60 ° C, therefore not very dangerous as to the risks of explosion and which, moreover, is very volatile and naturally biodegradable and odorless, which eliminates risks of pollution of the soil and water of the places where the shows using the device of the invention. A hydrocarbon commercial type of this type is for example known under the name of ISOPAR® L, produced and distributed by ExxonMobil Chemical.

The ignition device 3 comprises two pairs of electrodes 5a, 5b, said electrodes being preferably equidistant from the longitudinal axis ZZ 'of the nozzle 4, and defining for example a "rectangle" around said nozzle.

This configuration of the electrode pairs in a rectangle around the nozzle is particularly advantageous because it ensures the forming an electric arc between the different electrodes, without wear excessive of these or transformers. So, even in case of accidental modification of the spacing between two electrodes, an arc may always be formed between two other electrodes of the other pair.

However, other provisions of the pairs may be provided for of electrodes 5a, 5b, for example square, or three electrodes at the top an equilateral triangle around the nozzle 4 or both electrodes of the same pair superimposed.

Indeed, to obtain the secure ignition device 3 according to the invention; the only constraint is that the conductive tips 5 ₂ of two electrodes of the same pair of electrodes 5a, 5b are spaced from each other by a maximum of 1.5 cm, in order to be able to produce between them an electric arc and that said electrodes are sufficiently close to the nozzle 4 so that said electric arc is produced at the periphery of the emission orifice 4 ₁ of the nozzle 4, and therefore at the periphery of the hydrocarbon jet when the latter is emitted to ignite it.

Each pair of electrodes 5a, 5b is further powered independently by a clean power supply means such as a high voltage transformer known to those skilled in the art, in order to produce an electric arc and ignite a flame when issuing a jet of hydrocarbon through the nozzle. This independent power supply of each pair of electrodes prevents ignition failure due to breakage untimely one of the transformers.

Each transformer supplying the two pairs of electrodes is electrically connected, via a base placed in the housing 2 and electrical cables, to an external power source audit flame generator 1.

The two pairs of electrodes being powered independently, one thus prevents any failure of one of the transformers and ensures producing at least one electric arc between at least two electrodes of pairs 5a, 5b and the ignition of a flame during the emission of the jet of hydrocarbon at the nozzle 4.

The nozzle 4 used is preferably a steel nozzle, with a spraying orifice 4 ₁ tungsten, capable of working at pressures greater than 20 bar.

The two pairs of electrodes 5a, 5b of the ignition device 3 are composed of long electrodes consisting of an insulating ceramic body 5 ₁ , partially embedded in the housing 2 and surmounted by a conductive tip 5 ₂ tungsten. However, other types of electrodes known to those skilled in the art can also be used.

These electrodes are placed in such a way that the distance between their tips ₂ is between 0.5 cm and 1.5 cm, and preferably in a rectangle, equidistant from the orifice 4 ₁ of the nozzle 4, so that a an electric arc occurs between their peaks ₂ when said transformers connected to said pairs of electrodes are electrically powered.

A hydrocarbon jet being sprayed by the nozzle 4 under a significant pressure greater than 20 bar, said pairs of electrodes 5a, 5b are arranged such that an electric arc formed between the tips _{2 does} not occur through said jet of hydrocarbon sprayed but on the periphery thereof in order to obtain an ignition of said jet which is reliable and secure.

In order to obtain the formation of an arc between the ends of the tips ₂ of the electrodes closest to the periphery of the micronized hydrocarbon jet, said ends are preferably folded at right angles and directed towards the longitudinal axis ZZ ' of the nozzle 4.

Preferably, in order to obtain a flame generator 1 and a 3 ignition device usable in all conditions and all environments, we guaranteed tightness and rigidity of the assembly between the bodies 5, electrodes and housing 2 using a stainless steel cable gland, an insulating resin being further cast inside said housing for preserve moisture and the intrusion of liquids all components of the flame generator 1 placed in said housing 2.

The flame generator 1 is thus made perfectly tight against moisture and the introduction of liquid into the housing 2, which makes its possible use on or in the water to create flames at the surface of the water.

This flame generator 1 can be implemented in a very simple by a single operator or, where appropriate, so automatic. In practice, the flame generation generator 1 can placed on a mobile or fixed support placed on the ground or on a surface where one wants to produce a pyrotechnic show, or alternatively, on climbing machinery to vary the levels of formation of flames when on the ground or installed under a so-called surface of water and emerging the generator 1 punctually for to emit flames by surprise out of the water.

In each case, said generator 1 is connected to a reservoir hydrocarbon through pipes and to a device electric firing unit (not shown) connected to the base for powering electricity transformers of the ignition device 3. A motor pump metering device, also not shown, supplies the nozzle 4 with a flow hydrocarbon at a pressure of between 20 and 110 bar depending on the length of the desired flame.

As soon as it is desired to produce a flame, an operator (or an automatic firing device if appropriate) triggers, from the firing device, the power supply of the transformers and the pairs of electrodes 5a, 5b, so as to produce at least one electric arc between the points ₂ of these electrodes. Shortly thereafter, said operator (respectively the automatic device) triggers the hydrocarbon inlet to the nozzle 4 where it is sprayed in the form of a rectilinear fine jet and ignited by an electric arc produced between the tips 5 ₂ two electrodes at the periphery of the jet at the spray orifice 4 _{1 of} said nozzle 4. In order to prevent any risk of pollution, the ignition device may further comprise, in a known manner, an arc detector at the level of the electrodes, which thus makes it possible to block the admission of hydrocarbon to the nozzle when no arc is formed between the electrodes.

Claims (9)

Secure ignition device (3) for a spectacle generator (1) for the spectacle comprising at least one fuel projection means (4), said secure ignition device (3) comprising a pair of electrodes (5a) connected to at least one electrical supply means for generating at least a first electric arc capable of igniting a jet of fuel projected by said projection means (4) close to said electrodes, characterized in that said ignition device comprises at least at least one second pair of electrodes (5b) connected to said average power supply means and capable of generating at least one second electric arc, simultaneously or not with said first electric arc, for igniting said fuel jet, said pairs of electrodes being installed on a frame (2) and further sealingly connected to said power supply means (s). Secure ignition device according to claim 1, characterized in that the at least two said pairs of electrodes (5a, 5b) are connected to the same power supply means. Secure ignition device according to claim 1, characterized in that it comprises at least two so-called power supply means able respectively to supply the at least two said pairs of electrodes (5a, 5b) independently of one another. another, so as to ensure the presence of at least one arc at the time of emission of said fuel jet. Secure ignition device according to one of claims 1 to 3, characterized in that each said electrode comprises a tungsten conductor tip and the distance between the ends of the conductive tips of two so-called electrodes of at least one pair of electrodes is between 0.5 and 1.5 cm, said ends of the tips (5 ₂ ) of said electrodes converging preferably towards the projection axis ZZ 'of said projection means (4) so as to produce an electric arc at most near said fuel jet, and preferably at the periphery of said jet. Secure ignition device according to one of the preceding claims, characterized in that said electrodes are equidistant from the axis ZZ 'of said projection means (4). Secure ignition device according to one of the preceding claims, characterized in that said electrodes define a rectangle or a square whose angles they occupy, the axis ZZ 'of said projection means (4) passing through the center of said square or rectangle. Secure ignition device according to one of claims 4 to 6, characterized in that said ends of the conductive points (5 ₂ ) of said electrodes are folded at right angles towards said projection axis ZZ 'of said projection means relative to the said electrodes, these being parallel to said ZZ 'axis. Flame generator for the show featuring a secure ignition device (3) according to one of claims 1 to 7. Use of a secure ignition device (3) according to one Claims 1 to 7 or a flame generator (1) according to claim 8 for producing flames, preferably flames of great length.

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