FR3079020A1 - BLUE SMOKE BURNER FOR THE DEPOLLUTION OF A COATING PLANT, COATING PLANT AND DELEGATION METHOD THEREOF - Google Patents

Abstract

Blue smoke burner for depollution of a coating plant, coating plant and associated depollution process Burner (32) for equipping an oven (2) with a coating plant (1) for manufacturing asphalt mixes hot bituminous material from aggregates and bitumen, the burner (32) being characterized in that it comprises at least: - a first conduit (20) intended to be connected to an oxidizer supply line (38) in upstream of a burning head (3) for supplying said oxidant supply line (38) with vapors and / or bitumen dust, and - a second duct (21) intended to open into said furnace (2) for supplying in the latter vapors and / or dust bitumen. The burner, the coating plant and the depollution process according to the invention are particularly intended for the production of bituminous mix without significant relaxation of blue fumes in the atmosphere.

Description

BLUE SMOKE BURNER FOR THE DEPOLLUTION OF A COATING PLANT, COATING PLANT AND RELATED DEPOLLUTION METHOD

The present invention relates to the general technical field of coating equipment and methods, for example for the manufacture of bituminous coated products from bitumen and aggregates, in particular gravels of various natures, of various sizes and sizes, with a view to produce a finished coated product usable for example in the field of construction and public works.

The present invention relates more particularly to a burner for equipping an oven with a coating plant intended for manufacturing hot bituminous mixes from aggregates and bitumen, said burner comprising at least one burner head and one pipe for 'supply of oxidant to the burner head to produce at the latter a flame intended to heat the interior of said furnace.

The present invention also relates to a coating plant for the manufacture of hot bituminous mixes from aggregates and bitumen, said plant comprising an oven and a burner.

The present invention further relates to a method of depolluting a coating plant intended for manufacturing hot bituminous mixes from aggregates and bitumen, said plant comprising an oven, said method comprising at least one step of equipping said oven with a burner comprising at least one burner head and an oxidant supply line to the burner head to produce at the latter a flame intended to heat the interior of said oven.

Coating plants are known which make it possible to manufacture bituminous mixes, that is to say in practice to produce a hot mixture of solid products of the gravel and / or sand type with at least one substantially molten, soft binder, and / or hot liquid, such as bitumen. Such a mixture is used in particular in the field of construction, in particular for making communication routes (for example a road pavement, a sidewalk, an airport runway, etc.), public works (course of school, parking, etc.), buildings or for civil engineering (for example as a coating or as a sealant), etc. Such plants generally each have an oven for drying gravel, in order to remove all traces of water from them, the dried gravel then being mixed with hot bitumen to form bituminous mixes. The bituminous mixes are then stored within the plant and then loaded into a truck for disposal.

These known power stations, if they give overall satisfaction, do not the less present a major drawback, resulting from the emission and the release in the atmosphere of smoke called "blue smoke" particularly polluting and harmful. This blue smoke is in particular formed by bitumen vapors and / or dusts, and comes in particular from the storage of bitumen, the manufacture of bituminous mixes, and the storage and disposal of the latter. The blue fumes emitted by known power stations present a health risk for people working in them or living nearby, as well as for personnel who are employed in the use of bituminous mixes.

In order to remedy this problem, a coating plant has been proposed implementing a supply of blue smoke directly into the oven. This known coating plant is not entirely satisfactory, however, since its production capacity is significantly reduced compared to a plant without such a power supply.

The objects assigned to the invention therefore aim to remedy the various aforementioned drawbacks and to propose a new burner for asphalt mixing plant allowing the latter to produce bituminous mixes in a particularly clean, environmentally friendly and plan safe manner. sanitary, while allowing good reliability and a high production yield.

Another object assigned to the invention aims to propose a new burner for coating plant, allowing, whatever the production capacity of the plant, to minimize the discharge of bituminous pollutants.

Another object of the invention is to propose a new burner that is easy and inexpensive to install on a coating plant under construction or a preexisting plant.

Another object assigned to the invention aims to propose a new coating plant of relatively simple and inexpensive construction.

Another object assigned to the invention aims to propose a new coating plant whose design makes it possible to optimally limit polluting emissions into the atmosphere.

Another object assigned to the invention aims to propose a new coating plant, the design of which makes maintenance easier.

Furthermore, another object assigned to the invention aims to propose a new depollution process for a coating plant making it possible to continuously limit pollutant emissions based on bitumen in the atmosphere, whatever the mode. of the central unit or the burner and without significantly impacting the latter's efficiency.

The objects assigned to the invention are achieved using a burner to equip an oven with a coating plant intended for manufacturing hot bituminous mixes from aggregates and bitumen, said burner comprising at least one burner head and an oxidant supply pipe to the burner head to produce at the latter a flame intended to heat the interior of said furnace, the burner being characterized in that it further comprises at least:

- A first conduit intended to be connected to the oxidant supply line upstream of the burner head to supply said oxidant supply line with bitumen vapors and / or dusts from the bitumen used by the power plant and / or bituminous mixes manufactured by the latter, and

- A second conduit intended to lead into said furnace to bring into the latter vapors and / or dust of bitumen from the bitumen used by the plant and / or bituminous mixes manufactured by the latter.

The objects assigned to the invention are also achieved using a coating plant for the production of hot bituminous mixes from aggregates and bitumen, said plant comprising an oven and being characterized in that it further comprises at least one burner as mentioned above.

The objects assigned to the invention are also achieved using a depollution process of a coating plant intended for manufacturing hot bituminous mixes from aggregates and bitumen, said plant comprising an oven, said method comprising at least:

a step of equipping said furnace with a burner comprising a burner head and an oxidant supply pipe to the burner head to produce at the latter a flame intended to heat the interior of said furnace, said method being characterized in that it further comprises

a step of supplying the oxidant supply pipe, upstream of the burner head, with bitumen vapors and / or dusts originating from the bitumen used by the plant and / or bituminous mixes manufactured by the latter, and a step of conveying bitumen vapors and / or dust from the bitumen used by the plant and / or bituminous mixes produced by the latter in the furnace.

Other particularities and advantages of the invention will appear and appear in more detail on reading the description given below, with reference to the appended drawings, given only by way of illustrative and nonlimiting examples, in which:

- Figure 1 illustrates a schematic view of a burner fitted to a coating plant, according to a first embodiment of the invention.

- Figure 2 illustrates a schematic view of a burner fitted to a coating plant, according to a second embodiment of the invention.

- Figure 3 illustrates a perspective view of a burner according to the invention, which can be that fitted to the coating plant of Figure 1 or Figure 2.

- Figure 4 illustrates a sectional view along a plane P of the burner of Figure 3.

The invention relates, according to a first aspect, as illustrated in the figures, a burner 32 for equipping an oven 2 with a coating plant 1 intended for manufacturing hot bituminous mixes from aggregates and bitumen.

Thus, in known manner, the coating plant 1 comprises in particular an oven 2, which is preferably designed to dry the aggregates, that is to say designed to heat treat said aggregates in order to remove the water that would be incorporated into them. The oven 2 is therefore advantageously an aggregate drying oven, but can optionally form a unit for manufacturing bituminous mixes in the case where the hot bitumen / aggregates mixture is carried out at least partially inside the oven 2.

The burner 32 is therefore advantageously intended to equip the coating plant 1, and more preferably the oven 2 of said plant 1, or even to form part of the plant 1, to perform two main functions.

The first function assigned to the burner 32 is to ensure, in a conventional manner, the heating of the oven 2 which it is intended to equip, that is to say an increase in the temperature inside said oven 2, and this in particular for drying aggregates.

A second function of the burner 32 is more specific to the invention, and advantageously relates to the depollution of the coating plant 1, the burner 32 being intended to destroy, in particular by burning, in an effective and controlled manner, the vapors and / or bitumen dust from the bitumen used by the plant 1 and / or bituminous mixes produced by the latter, preferably inside the oven 2 of the coating plant 1. Thus, advantageously, the burner 32 has, in addition to its traditional function of heating the oven 2, a pollution control function for the coating plant 1, the burner 32 being intended to be mounted, that is to say set up or installed, in combination with the oven 2 of the coating plant 1 to achieve both its heating function and its depollution function.

Thus, the coating plant 1 preferably constitutes a hot bituminous mix production unit, that is to say in particular of a mixture of preferentially solid aggregates, and of a binder, advantageously of hydrocarbon type bitumen, preferably soft, liquid, viscous and / or hot melted. The bituminous mixes manufactured by plant 1 are in particular intended for use in public works, civil engineering, construction, or more generally all that relates to construction, in particular the construction of roads, airport runways , but also for other applications, for example as a sealing or insulation coating. The coating plant 1 is therefore in particular intended for storing and using bitumen, and in particular hot bitumen, and mixing the latter with aggregates to produce hot bituminous mixes, for example at a temperature between 100 and 250 °. C, preferably between 120 and 180 ° C.

Advantageously, the aggregates, sometimes called aggregates, are formed by solid granular products, and are included in the group comprising gravel, crushed pebbles, fines (or "filler") and sand. The aggregates preferably have a small particle size, for example they have an average size (or an average diameter) substantially less than or equal to 125 mm, or even less than or equal to 20 mm. Preferably, the term bitumen designates any bitumen-type binder used for the manufacture of mixes, whether it is natural bitumen (for example from deposits), plant (for example derived from plants), synthetic or artificial ( for example from crude oil and / or petrochemicals). Preferably, the bitumen used in the coating plant 1 is mainly (that is to say at least in majority) formed by a mixture of hydrocarbons of petroleum origin.

In known manner, the coating plant 1 produces in particular, undesirably, vapors and / or dust of bitumen, which come from the bitumen used by the plant 1 and / or bituminous mixes manufactured by the latter. These bitumen vapors and / or dusts are commonly called “blue smoke” in the field, and constitute by-products or undesirable very polluting residues resulting in particular from the implementation of the coating plant 1. In fact, there It is well known to manufacturers that the production of bituminous mixes in coating plants forms blue fumes charged with particles, dust and / or vapors, of bitumen. We also know that blue fumes also come from the storage and evacuation of bituminous mixes within plant 1. Blue fumes are also formed during the storage of bitumen intended to be used by plant 1 for manufacturing bituminous mixtures, that is to say bitumen intended to be mixed with aggregates.

According to the invention, the burner 32 comprises at least one burner head 3 and an oxidant supply line 38 to the burner head 3 to produce at the latter a flame 4 intended to heat the interior of said oven 2 In other words, the oxidant supply line 38 is advantageously designed to convey, at least to the burning head 3 (also called combustion head 3), an oxidant, which is preferably air and more preferably the oxygen contained in the air, to allow the production of flame 4, that is to say in particular the production of combustion, one of the reactants of which is said oxidizer. Preferably, the burner 32 is therefore designed to produce the flame 4 from a position or zone defining the burning head 3, and this using the oxidant supply pipe 38, the flame 4 ensuring advantageously the main function of heating the oven 2 (and more advantageously still a function of drying the aggregates). In summary, advantageously, the oxidant supply line 38 is designed to supply oxidant to the burner 32.

The oxidizer supply line 38 may for example be formed from a single line, or from a plurality of lines preferably fluidly connected to each other.

Advantageously, as illustrated in FIG. 4, the burner 32 also comprises at least one fuel supply line 39, 46 to the burner head 3 to produce the flame 4 at this level, that is to say that is to say to carry out combustion, and this preferably in combination with the oxidant supply line 38 or more precisely the oxidant conveyed by the latter.

Thus, the fuel supply line 39, 46 is advantageously designed to convey, at least to the burner head 3, a fuel, which is in particular liquid or gaseous, such as for example natural or synthetic gas, fuel oil, heating oil, or any other suitable fuel for the production of the flame 4 necessary for heating the oven 2 (preferably drying, optionally mixing) of a coating plant 1. Such a configuration therefore allows the burner 32 advantageously ensuring its first conventional heating function for the interior of the furnace 2. According to the preferred embodiment of FIG. 4, the burner 32 comprises a first fuel supply line 39 intended to convey liquid fuel, and a second fuel supply line 46 intended for conveying gaseous fuel, said liquid fuel supply lines 39 and gaseous 46 advantageously being d istinct and intended to be used alternately, that is to say in a non-concomitant manner. In other words, in the preferred embodiment of FIG. 4, it is possible, during the implementation of the burner 32, to change (that is to say to alternate) the nature of the fuel ( liquid or gaseous) used to produce the flame 4.

The second fuel supply line 46 comprises for example a major conduit and a plurality of minor conduits 46a, 46b forming a corolla, said minor conduits 46a, 46b being fluidly connected to the major conduit to extend from the latter to the burning head 3, the major conduit being located upstream of the minor conduits 46a, 46b.

According to other embodiments not illustrated, the burner 32 only comprises the first fuel supply line 39 or only the second fuel supply line 46, the burner 32 then being intended to produce the flame 4 only with a liquid fuel or with a gaseous fuel, without alternation.

The burner 32 can for example form a gas burner with forced air or a pulsed burner with fuel oil, depending on the nature of the fuel (combustible gas or fuel oil).

The burner head 3 is thus preferably formed, conventionally, by the position or zone where the production of the flame 4 begins, and it can also advantageously include, just as conventionally, as illustrated in FIG. 4, an injection means of fuel disposed at the end of the fuel supply line 39, 46 (or forming one end of the latter). The fuel injection means therefore preferably forms both a part, preferably an extreme part, of the fuel supply line 39, 46, and at least a part of the burner head 3.

For example, according to the preferred embodiment of Figure 4, the fuel injection means comprises a primary head for injecting liquid fuel 45 disposed at the end of the first fuel supply line 39, and a plurality of secondary gaseous fuel injection heads 47a, 47b disposed at respective ends of respective minor conduits 46a, 46b, in particular at the ends of the corolla.

The burner head 3 is preferably located downstream of the oxidant supply line 38 (that is to say at the level of the downstream of the latter or at the level of a downstream part of the latter. ).

Advantageously, the flame 4 extends at least partially, preferably entirely, within (that is to say inside) the oven 2. Preferably, the burner head 3 and the pipe oxidizer 38 are arranged so as to produce said flame 4 from the burning head 3, in the furnace 2, said flame 4 being formed, with respect to the burning head 3, opposite the pipe d oxidant supply 38. Thus, the flame 4 advantageously extends from the burner head 3, opposite and / or outside of the oxidant supply line 38. The burner 32 is therefore advantageously intended to equipping said oven 2 to raise the temperature inside the latter, the drying of the aggregates arranged inside the oven being thus preferably carried out using the heat provided by said flame 4, which extends towards inside the oven 2 from the top e of burning, which is also preferably positioned inside the furnace 2.

Said burner head 3 and / or said oxidant supply line 38 is / are therefore advantageously intended to be at least partially installed and / or mounted on and / or in said furnace 2. Preferably, the burner 32, by means of the flame 4, is intended to heat the interior of the oven 2 to dry the aggregates.

The burner 32 is optionally partly formed by a burner already installed within the coating plant 1, for example a pre-installed burner equipping the oven 2 with a pre-existing coating plant 1, this pre-installed burner comprising for example the head burner 3 and the oxidant supply line 38. Preferably, however, the burner 32 is a new burner which forms a module designed to equip a coating plant 1 and in particular the oven 2 thereof.

Preferably, as illustrated in the figures, the oxidant supply pipe 38 has a tubular shape (at least in part, or even entirely) inside which the oxidant intended to supply the flame 4 circulates. Advantageously, the fuel supply line 39, 46 is positioned inside the oxidant supply line 38 and more precisely inside the tubular form, so that the oxidant circulates in the supply line. oxidant supply 38 and around the fuel supply line 39, 46, to produce the flame 4 when it is mixed with a fuel flowing in the fuel supply line 39, 46. Preferably, the supply line fuel supply 39, 46 also has a tubular shape, but the diameter of which is smaller than that of the tubular shape of the oxidant supply pipe 38.

Advantageously, as illustrated in FIG. 4, the lines for supplying oxidant 38 and fuel 39, 46 are substantially elongated and positioned in a substantially coaxial manner, or along respective axes that are substantially parallel. According to the preferred embodiment of FIG. 4, the fuel supply line 39, 45 is positioned substantially coaxially with the oxidant supply line 38, such as for example the first fuel supply line 39, or along a longitudinal axis substantially parallel to a longitudinal axis of the oxidant supply line 38, such as for example the second fuel supply line 46.

Advantageously, the burner 32 further comprises an ignition means 40 designed to allow the production of the flame 4, in particular by initiating a combustion reaction between the oxidant conveyed by the oxidant supply line 38 and the fuel conveyed by the fuel supply line 39, 46. Said ignition means 40 is therefore preferably designed to produce an ignition source, such as a spark, an electric arc, a hot spot or an ignition flame ( for example produced from LPG), at the level of the burner head 3 (and / or in the immediate vicinity of the latter).

Advantageously, the burner head 3 is formed by the zone or position where the flame 4 begins to exist, that is to say the zone where the oxidant supplied by the oxidant supply line 38 meets, the fuel conveyed by the fuel supply line 39, 46, and the ignition source produced by the ignition means 40. Preferably, the oxidant supply line 38 has at one of its ends a primary outlet mouth 42 opening inside said oven 2 and located in the latter. Preferably, the burner head 3 is located substantially at (or in the immediate vicinity) of the primary outlet mouth 42, the fuel injection means, and the ignition means 40. The flame 4 is therefore advantageously produced substantially at the level, that is to say from, from a zone adjacent to the primary outlet mouth 42, the fuel injection means, and the ignition means 40.

The burner 32 also preferably includes a flame deflector 41 designed to regulate the flame 4, for example to keep it in position. The deflector 41 is advantageously positioned at the level of the burning head 3 (or even part of it) inside the oxidant supply pipe 38. This deflector 41 makes it possible, in particular, to pass a flow of oxidant (from the oxidant supply line 38) to generate the turbulence necessary to maintain the flame 4 in position. Preferably, the flame deflector 41 has a generally substantially circular shape and / or a complex shape of the type having a plurality of vents. In summary, the burner 32 is preferably designed to produce the flame 4 inside the drying oven 2 from an oxidizer coming from the oxidant supply line 38, from a fuel coming from the supply line. fuel supply 39, 46, and an ignition source from the ignition means 40, in order to raise the temperature in the oven 2 and thus proceed to the drying of the aggregates. Preferably, as we have seen, the fuel used by the burner 32 is formed by a liquid fuel (for example from crude oil) or a gaseous fuel (for example natural or synthetic gas), the oxidizer used by ie burner 32 being for example formed by air, and more preferably by the oxygen contained in the air.

Advantageously, as illustrated in the figures, the furnace 2 comprises, in a known manner, a casing 5 and it optionally forms a drum of which at least part can be rotated, in particular to better carry out the drying of the aggregates when said flame 4 is produced by the burner 32, preferably inside the casing 5. For example, in a known manner, the aggregates are introduced into the drying oven 2 and evacuated from the latter by means of a conveyor (not illustrated). Optionally, the furnace 2 is designed so that the mixing of the aggregates and the bitumen is carried out inside the casing 5, the rotation of the drum which advantageously forms the furnace 2 making it possible, for example, to produce and / or homogenize the mixture.

The oxidizer supply line 38 advantageously has one end or part opening out inside the oven 2 and another end or part opening out outside the oven 2 (preferably in the first pipe 20), for example one end or part positioned inside the oven 2 (and more precisely the casing 5), and another end or part positioned outside the latter. The oxidant supply line 38 is therefore preferably designed for the production, for example at its first end, of a flame 4 inside the casing 5 of the furnace 2, in order to ensure the production of heat within of the oven 2 allowing the drying of the aggregates.

Preferably, the coating plant 1 and / or the burner 32 further comprises at least one means 6 for collecting bitumen vapors and / or dust from the bitumen used by the plant 1 and / or bituminous mixes produced by the latter. . Thus, the collection means 6 can be part of the coating plant 1 and / or of the burner 32, depending for example on whether the collection means 6 is already pre-installed within a pre-existing coating plant (where the we would install the burner 32 of the invention), integrated later within the latter (in particular at the same time as the installation of the burner 32), or installed within a new coating plant during its construction (in especially at the same time as the burner 32).

As illustrated in the figures, the coating plant 1 advantageously comprises at least one means for storing bitumen 7, for example formed by a tank, as well as a means for storing bituminous mixes 8, for example formed by a storage hopper , an evacuation zone 9 for bituminous mixes, and a loading system 10 for loading a vehicle 11, for example a truck, with bituminous mixes, in said evacuation zone 9. Advantageously, the plant 1 also comprises a means for producing bituminous mixes, said means of manufacture being able to be formed, as we have seen, at least in part by the furnace 2, in particular if the latter forms a rotary drum. In fact, said means for producing bituminous mixes is preferably designed to mix bitumen (and in particular the bitumen stored in the plant 1 by said bitumen storage means 7) and aggregates (which are for example stored beforehand power plant 1 within an aggregate storage unit, not shown).

Bitumen dust is for example formed by small particles detached from the aggregates, in particular during the drying and / or the manufacture of coated materials, and which have been covered at least in part by a certain amount of bitumen, in particular hot. Bitumen dust is also optionally at least partly formed by small particles of bitumen which are at least partially solidified. Bitumen dust preferably has a very small particle size, for example they have an average size (or an average diameter) less than or equal to 0.2 mm, or even less than or equal to 20 μm. For example, the bitumen vapors are formed by volatile organic compounds (VOCs) and / or by aerosols of hydrocarbon molecules, said volatile organic compounds and / or aerosols being in particular derived from bitumen and in particular hot bitumen. Thus, the collecting means 6 advantageously equips the plant 1 to collect, that is to say collect, or even collect, the bitumen vapors and / or dusts originating and / or formed within the plant 1.

Preferably, the coating plant 1 comprises one or more collection points, which are for example designed to allow the evacuation of the bitumen vapors and / or dust from the coating plant 1 out of the bitumen storage means. 7, means for manufacturing bituminous mixes, means for storing bituminous mixes 8, and / or the discharge zone 9 for bituminous mixes, said collection points being for example formed by orifices or zones.

Preferably, the collection means 6 comprises at least one (and more preferably several) collection conduit (s), the one (s) of which is / are connected (each) to a respective collection point of the plant 1, the said collection point (s) being positioned respectively in the bitumen storage means 7, the means for manufacturing bituminous mixes, the means for storing bituminous mixes 8 , and / or the discharge area 9 for bituminous mixes. For example, as illustrated in the figures, the collection means 6 comprises at least one or more primary 12, secondary 13, tertiary 14, and / or quaternary 15 collection conduits, the one (s) which (s) is / are connected ( s) respectively by means of bitumen storage 7, by means of manufacturing bituminous mixes (not illustrated), by means of storage of bituminous mixes 8, and / or at the discharge zone 9 of bituminous mixes.

Preferably, as illustrated in FIG. 1, the collecting means 6 further comprises at least one single main collecting conduit 16 where several of the collecting conduits 12, 13 meet (that is to say fluidly join together), 14, 15, or even all the collection conduits 12, 13, 14, 15. Alternatively, as illustrated in FIG. 2, the collection means 6 comprises at least main primary collection conduits 17 and separate secondary 18 bringing together (c ' that is to say putting in fluid communication) each one or more collection conduits 12, 13, 14, 15, the main primary collection conduit 17 bringing together, for example, said secondary 13 and tertiary collection conduits 14, while the main conduit secondary collection 18 brings together, for example, said primary 12 and quaternary collection conduits 15. Preferably, as illustrated in FIG. 2, said main primary collection conduits 17 and seco ndaire 18 themselves gather (that is to say join fluidically), downstream, at a branch 19 (which advantageously forms part of the collecting means 6).

Preferably, the number and configuration of the collection conduits 12, 13, 14, 15, 16, 17 are not necessarily fixed, and may vary from one coating plant 1 to another, for example according to the desired configuration of control unit 1, the desired treatment for blue smoke, the equipment available, the flow rate for collecting blue smoke, etc.

According to the invention, the burner 32 further comprises at least a first conduit 20 intended to be connected to the oxidant supply line 38 upstream of the burner head 3 to supply the oxidant supply line 38 with vapors and / or bitumen dust from the bitumen used by the plant 1 and / or bituminous mixes manufactured by the latter. The first conduit 20 is therefore preferably fluidly connected with the oxidant supply line 38, more preferably upstream of the burning head 3 (that is to say upstream of the flame 4 with respect to a flow of oxidizer which feeds the latter), more preferably still outside the oven 2, for conveying said vapors and / or bitumen dust from the first conduit 20 to the oxidant supply line 38, which will then convey said vapors and / or bitumen dust from the first condit 20 to the flame 4.

The first conduit 20 may for example be formed of a single conduit, or of a plurality of separate conduits preferably fluidly connected to each other.

Preferably, the first conduit 20 also routes into the oxidant supply line 38, at the same time as said bitumen vapors and / or dusts, at least part of the oxidant allowing the production of the flame 4, the oxidant being in practice formed by air (more preferably the oxygen contained in the air) charged with said bitumen vapors and / or dusts. Advantageously, the first conduit 20 is intended to be connected on the one hand to the collecting means 6 and on the other hand to the oxidant supply line 38 upstream of the burner head 3, to supply said flame 4 with vapors and / or bitumen dust coming from said collecting means 6, and more precisely by oxidizer loaded or accompanied by said bitumen vapors and / or dust. Thus, the first conduit 20 advantageously establishes a fluid connection between the collecting means 6 and the oxidant supply line 38, for example a part of the latter which is located outside the furnace 2 and upstream of the burner head 3 and / or flame 4 that burner 32 is intended to produce. Preferably, the flame 4 is therefore produced downstream of the burner 32 while the bitumen vapors and / or dusts are introduced into the burner 32 upstream of the latter and more precisely in the first conduit 20 to the 'upstream of the latter.

Preferably, the first conduit 20 is designed to bring at least a first portion (preferably non-zero, but alternately zero, or alternatively forming the whole) of the bitumen vapors and / or dust from the power plant 1, and preferably collected by the collecting means 6, up to the oxidant supply line 38, the latter being in particular designed so that said first portion of bitumen vapors and / or dusts then leave said supply line oxidizer 38 at the level of the burner head and therefore at the level of the flame 4, at the same time as and / or with the oxidant intended to supply the latter and resulting, as we have seen, from the supply line of oxidizer 38. Such a configuration advantageously makes it possible to burn the first portion of bitumen vapors and / or dust collected passing through said first conduit 20 then the oxidizer supply conduit 38 at the same time. ps that the oxidizer (formed by air and more preferably the oxygen contained in the air) used by the burner 32 to produce the flame 4, that is to say in other words to cause the destruction of the first portion of bitumen vapors and / or dusts thanks to the combustion of the oxidizer and the fuel. In fact, the first portion of the bitumen vapors and / or dust is advantageously mixed with the oxidizer used by the burner 32 to produce the flame 4, the oxidant preferably being in practice at least in part of the air (preferably the dioxygen contained in the air) from the collecting means 6 and charged (that is to say mixed) with the first portion of the bitumen vapors and / or dusts.

Preferably, as illustrated in FIGS. 1 to 4, the burner 32 is designed so that the oxidizer, charged with the first portion of the bitumen vapors and / or dust, is conveyed by the oxidant supply line 38 of the first conduit 20 to the burner head 3, the first conduit 20 and the oxidant supply line 38 having fluid continuity in the manner of a tubular shape whose section is constant or remains in the same order of magnitude.

Still according to the invention, said burner 32 also comprises at least one second conduit 21 intended to open into said oven 2 to bring into the latter bitumen vapors and / or dust from the bitumen used by the plant 1 and / or mixes bituminous produced by the latter. Preferably, the second conduit 21 opens directly into said furnace 2, that is to say without passing through the oxidant supply line 38 (or in other words without being fluidly connected directly with the latter), to bringing said bitumen vapors and / or dust directly from the bitumen used by the plant 1 and / or bituminous mixes produced by the latter directly into the oven 2. Preferably, the first and second conduits 20, 21 are separate from each other.

The second conduit 21 can for example be formed of a single conduit, or of a plurality of separate conduits preferably fluidly connected to each other.

Thus, the second conduit 21 is advantageously intended to be connected on the one hand to the collecting means 6 and on the other hand to the furnace 2 to bring bitumen vapors and / or dust from the collecting means 6 (preferably directly) into the oven 2. In other words, the second conduit 21 advantageously establishes a direct fluidic connection between the collecting means 6 and a part of the oven 2 (formed for example by the interior of the casing 5), and preferably at 1 downstream vis-à-vis the flame 4 that the burner 32 is intended to produce, that is to say without direct fluid communication with the oxidant supply line 38. Thus, preferably, the second line 21 is designed to bring at least a second portion (which may be zero or non-zero, or alternatively constitute the whole) of the bitumen vapors and / or dust from the power plant 1, and preferably collected by the collection means 6, up to u in the oven 2 and more precisely up to the interior of said oven 2, and this separately and / or independently of the oxidant intended to supply said flame 4.

Preferably, the second conduit 21 is designed to bring bitumen vapors and / or dust from the power station 1, and more precisely from the collecting means 6 (and thus forming said second portion), to the flame 4 of so as to burn them, that is to say destroy them, even in the preferential event where the air (or the oxygen contained in the air) which surrounds them does not serve as oxidizer, as illustrated in the Figure 2. In other words, the first portion advantageously bathes in the oxidant (formed by air or preferably the oxygen contained in the air) supplied by the oxidant supply line 38 to the burner head 3 , to then be destroyed by a combustion reaction consuming said oxidant and said fuel and producing flame 4, while the second portion is preferentially conveyed directly into oven 2, optionally to flame 4 or to the vehicle. sinination of the latter so as to be destroyed by said flame 4 and / or the heat generated by the latter, and this without being in contact with the oxidant before it has been consumed in the combustion reaction producing said flame 4 .

Advantageously, as illustrated in FIGS. 1 and 2, the second conduit 21 comprises a secondary outlet mouth 43 opening into the furnace 2 and situated in the latter, said secondary outlet mouth 43 being optionally designed, as illustrated in FIG. 2, for bring the second portion into or near the flame 4 so as to be burned, that is to say destroyed or neutralized, by the latter. Said secondary outlet mouth 43 may thus optionally comprise a conical shaped piece 44 positioned around the primary outlet mouth 42, in the furnace 2, for concentrating a flow of air charged with said secondary portion (the third flow F3, as as will be seen below) closer to the flame 4.

Such an advantageous configuration, where at least part (or even all depending on the operating mode of the burner 32) of the bitumen vapors and / or dusts originating from the coating plant 1 (and more precisely coming from the collecting means 6) is driven towards destruction via the first conduit 20 then the oxidant supply line 38, while another part (zero or non-zero) of the bitumen vapors and / or dust is injected or reinjected directly into the furnace 2 (and more precisely inside the casing 5, or even in the flame zone 4) via the second conduit 21, is particularly effective in causing burning, that is to say here destruction by means of a combustion, bitumen vapors and / or dusts from power plant 1, thus preventing their escape outside the latter and the related pollution. In other words, thanks to the burner 32 of the invention, it is possible to avoid certain pollution (or at least greatly limit the risk and / or its importance) linked to an untimely release of blue fumes into the atmosphere, by destroying the latter within or near the coating plant 1.

Advantageously, said first and second conduits 20, 21 are intended to be connected (in particular fluidly) to a part of the collecting means 6, in particular to the same downstream part of the collecting means 6, for example a downstream part of the single main collection conduit 16, in particular a downstream end of the latter, as illustrated in FIG. 1, or to a part downstream of the primary primary 17 and secondary 18 collection ducts, in particular the branch 19, as illustrated in FIG. 2. Alternatively, said first and second conduits 20, 21 are respectively intended to be connected (in particular fluidically) to a part (for example an end) downstream of the main primary collection conduits 17 and secondary 18 respectively, said main collection conduits primary 17 and secondary 18, for example not in fluid communication with each other.

Preferably, the burner 32 also comprises means for establishing a second and / or a third gas flow F2, F3 for circulating the bitumen vapors and / or dusts within said first conduit 20 and / respectively or of said second conduit 21, the second gas flow F2 therefore also advantageously being circulated within the oxidant supply line 38 by the means for establishing a second and / or a third gas flow F2, F3. In other words, preferably, the means for establishing a second and / or a third gas flow F2, F3 makes it possible to set the air in motion and / or to promote its flow inside. of said first duct 20 (and therefore by extension also preferably inside the oxidant supply pipe 38) and / or of said second duct 21, the air thus set in motion making it possible to entrain the vapors and / or bitumen dust from the coating plant 1.

Advantageously, the air set in motion within the first conduit 20 will also be set in motion within the oxidant supply line 38, since the latter is connected (preferably fluidly) to the first line 20. This means that, preferably, an air flow (in particular the second gas flow F2) circulating within the first conduit 20 then circulates (preferably in full) within the oxidant supply line 38, the latter being positioned downstream relative to to the first conduit 20, the latter therefore being positioned upstream of said oxidant supply line 38. It can also be considered, optionally, that the first conduit 20 forms a specific upstream part of the oxidant supply line 38 , or that the latter forms a specific downstream part of the first conduit 20.

Advantageously, said means for establishing a second and / or a third gas flow F2, F3 also makes it possible to establish a first gas flow F1 supplying upstream said second gas flow F2 and / or said third gas flow F3. Thus, the means for establishing a second and / or third gas flow F2, F3 is also designed to circulate the bitumen vapors and / or dust within the collecting means 6. In other words terms, preferably, the means for establishing a second and / or a third gas flow F2. F3 makes it possible to set the air in motion and / or to promote the flow inside said collecting means 6, thus forming the first gaseous flow F1_, the air thus set in motion making it possible to entrain the vapors and / or bitumen dust from the power station 1 and collected by said collection means 6 via the collection points, and in particular those located at this time inside the collection means 6, towards said first conduit 20 and / or said second conduit 21.

Preferably, said bitumen vapors and / or dusts collected and the air which entrains them pass successively from said collecting means 6 to the first duct 20 and / or to the second duct 21 continuously, so as to form a continuous circulation of air more or less loaded (one can even say polluted) in bitumen vapors and / or dust between the upstream of the collection means 6 (in particular one or more collection points) and downstream of the first conduit 20 (and by extension l downstream of the oxidant supply pipe 38) and / or of the second pipe 21. Preferably, the first pipe 20 opens downstream into a supply (in particular with oxidizer) to the burner 32 and more preferably, as we have seen , in the oxidant supply line 38. The second line 21 preferably opens directly downstream in the furnace 2.

Advantageously, as illustrated in FIGS. 1 and 2, said means for establishing a second and / or a third gas flow F2, F3 comprises at least one primary ventilation means 22 of said first duct 20 (and therefore by extension also preferably from said oxidant supply pipe 38) and / or from said second pipe 21, said primary ventilation means 22 being positioned upstream of said first and second pipes 20, 21. Said primary ventilation means 22 is therefore in particular designed to ventilate said collecting means 6, said first duct 20 (and therefore by extension said oxidant supply pipe 38), and / or said second duct 21. Thus, the primary ventilation means 22 is in particular designed to circulate (that is to say to set in motion) the air on the one hand within the collecting means 6, the first conduit 20 (and therefore by extension of said oxidant supply line 38) and / or the second conduit 21, e t on the other hand inside said primary or secondary collection ducts 12, secondary 13, tertiary 14 and / or quaternary 15, as well as according to a first embodiment illustrated in FIG. 1, inside the main duct single collection 16, or according to a second embodiment illustrated in FIG. 2, inside said primary primary 17 and secondary 18 collection conduits.

Advantageously, as illustrated in the figures, said primary ventilation means 22 comprises at least one first primary fan 35. Optionally, as illustrated in the embodiment of FIG. 2, said primary ventilation means 22 also comprises a second primary fan 36.

According to the first embodiment, as illustrated in FIG. 1, said first primary fan 35 is connected to said main single collection duct 16, said first primary fan 35 being for example mounted on or in said main single collection duct 16, and preferably being the only fan of the primary ventilation means 22.

According to the second embodiment, as illustrated in FIG. 2, said primary ventilation means 22 comprises at least said first and second primary fans 35, 36 which are separate, and which are each connected to one of said main ducts of primary 17 and secondary collection 18. For example, each of the first and second primary fans 35, 36 is mounted on or in a different one of said primary primary and secondary 17 collection ducts 18. Alternatively, the primary ventilation means 22 comprises as much fans that there are collection ducts 12, 13, 14, 15, each fan being connected to a respective one of the collection ducts 12, 13, 14, 15. More preferably, the primary ventilation means 22 comprises advantageously as many fans as there are separate main collection ducts 16, 17, 18 connected (notably fluidly) directly or indirectly (for example via the emb anchoring 19) to said first and second ducts 20, 21, each fan being connected to a respective one of the main collecting ducts 16, 17, 18. Thus, optionally, the primary ventilation means 22 comprises at least two primary fans 35, 36, or even more, said primary fans 35, 36 each having substantially the same configuration and / or being arranged in parallel.

Preferably, the collection conduits 12, 13, 14, 15 come together (that is to say join fluidly) upstream of the primary ventilation means 22.

Advantageously, the primary ventilation means 22 constitutes a part of the burner 32. Optionally, said primary ventilation means 22 constitutes, without this necessarily invalidating the preceding sentence, a part of the coating plant 1, in particular a part of a pre-existing coating plant which would have been built by including a ventilation means which can be adapted to operate in a manner similar or identical to the primary ventilation means 22, if any, of the invention. For example, the primary ventilation means 22 forms a part of the collecting means 6, which amounts to saying that the collecting means 6 comprises the primary ventilation means 22, which it shares, for example, with the burner 32 and / or the rest of the plant 1.

Preferably, said first gas flow F1 has, for example within the collection means 6, a primary flow Q1. Preferably, the first gas flow F1 is an air flow advantageously circulating within the collection means 6 and which comprises the entire gas flow circulating (at a given time or during a given period) within the collection means 6 , said primary flow Q1 therefore advantageously comprising all of the air flow in the collection means 6. For example, the first gas flow F1 is formed by all of the different gas flows circulating in the different collection conduits 12, 13 , 14, 15, and / or is either formed by the gas flow circulating in the single main collection conduit 16, or else is formed by the two partial gas flows F'1, F ”1 circulating one in the conduit primary primary collection 17 and the other in the main secondary collection conduit 18, and / or else is formed by the gas flow circulating in the branch 19.

More preferably, said primary ventilation means 22 is designed to maintain said primary flow rate Q1 substantially constant, that is to say in particular stable over time. Thus, the primary ventilation means 22 is advantageously designed to circulate (that is to say set in motion) the air within the collection means 6, of the first duct 20 (and therefore by extension of said duct d '' supply of oxidizer 38) and / or of the second conduit 21, continuously and regularly, either by drawing outside or conditioned air, or by setting in motion the polluted air (that is to say charged with bitumen vapors and / or dusts collected), or by combining the two actions, so that the air flow circulating within the collecting means 6 (and preferably entraining the bitumen vapors and / or dusts collected) is constant over time. Such a configuration has in particular the advantage of ensuring a continuous and regular collection or extraction of the bitumen vapors and / or dust coming from the collection points of the power plant 1. For example, said primary ventilation means 22 is designed to “extract »Continuously and at the same primary flow rate constant Q1 the air charged with blue smoke (that is to say bitumen vapors and / or dust) outside the bituminous mix storage means 8, the bitumen storage means 7 , from the discharge area 9 for bituminous mixes, and / or from the means for manufacturing bituminous mixes, in order to bring at least a first part thereof to the oxidant supply line 38 via the first line 20 and / or at least a second part directly in the oven 2 via the second conduit 21.

Preferably, said primary ventilation means 22 is designed (or adjusted) to maintain the primary flow Q1 at a value of between 5,000 and 40,000 m ³ / h, more preferably between 10,000 and 20,000 m ³ / h, for example equal to around 18,200 m ³ / h and preferably constant, these flow values being given by way of illustration and without limitation. Of course, the value of the primary flow rate Q1 is advantageously adjusted as a function of various parameters, such as for example the size of the equipment of the coating plant 1, the desired operating mode of the burner 32 and / or of the plant 1, the speed of bituminous mix production and / or aggregate drying, etc.

Advantageously, said second flow F2 has a secondary flow at inlet Q2a of said first conduit 20. Preferably, the second gas flow F2 is a flow of air circulating within the first conduit 20, and it comprises the entire gas flow which circulates (at a given time and / or during a given period) within the first duct 20. Said secondary flow at inlet Q2a therefore advantageously comprises the entire air flow at the inlet or just after the inlet of the first duct 20, that is to say the air flow rate in an upstream part (or even the most upstream part) of said first duct 20. Preferably, said third flow F3 has a tertiary flow Q3 within said second line 21. Advantageously, the third gas flow F3 is a flow of air circulating within the second line 21 and comprising the entire gas flow which circulates (at a given time and / or during a given period) within the second d conduit 21, said tertiary flow Q3 therefore advantageously comprising the entire air flow within the second conduit 21. Advantageously, the second flow F2 also circulates within the oxidant supply line 38 where it has a flow at least equal (or higher in certain situations, as will be seen below) to the air flow at inlet Q2a.

Preferably, the burner 32 comprises a means 23 for regulating said secondary flow at input Q2a and said tertiary flow Q3. The regulating means 23 is therefore advantageously designed to control, that is to say increase or decrease at will, the secondary flow at input Q2a and the tertiary flow Q3, knowing that in principle the sum of the secondary flow at input Q2a and the tertiary flow Q3 is preferably substantially equal to the primary flow Q1. and this regardless of the operating mode of the burner 32.

Preferably, said regulating means 23 controls said secondary flow at inlet Q2a and said tertiary flow Q3 in interdependence, so that a reduction in the secondary flow at inlet Q2a results in a substantially proportional increase in said tertiary flow Q3 and vice versa. in principle, we preferably have the equation where the primary flow Q1 (preferably constant) is equal to the sum of the secondary flow at input Q2a and the tertiary flow Q3, i.e. Q1 = Q2a + Q3, which is verified over time , so that the regulating means 23 is advantageously designed to regulate inversely proportional said secondary flow at input Q2a and said tertiary flow Q3.

For example, as illustrated in the figures, said regulating means 23 comprises a first and a second valve system (s) 24, 25 respectively equipping said first and second conduits 20, 21. Preferably, said first and second valve systems ( s) 24, 25 each comprise at least one valve or a plurality of valves positioned in a complementary manner, and said valves being for example of the butterfly type. Of course, said valves can possibly be assimilated to shutters. Alternatively, the first valve system 24 rather equips the oxidant supply line 38.

Advantageously, said regulating means 23 is designed to manage said first and second valve systems 24, 25 in interdependence, so that, when the valve (s) of the first valve system (s) 24 are in the 100% open position, the secondary flow at inlet Q2a is then substantially equal to the primary flow Q1, and when the valve (s) of the second valve system (s) 25 are in the 100% closed position, the tertiary flow Q3 is substantially zero, and vice versa.

For example, said regulating means 23 comprises at least one servomotor (not illustrated) designed to control alone said first and second valve systems (s) 24, 25 which are then preferably in mechanical interdependence, that is to say in mechanical connection with each other, so that an opening movement of the valve (s) of one mechanically causes an equivalent closing movement of the valve (s) of the other and vice versa. Alternatively, said regulating means 23 comprises at least a first and a second servomotor (not illustrated) which are designed to drive respectively said first and second valve systems (s) 24, 25, which are then advantageously in electronic interdependence, it that is to say in electronic connection with each other via said two servomotors, so that an opening movement of the valve (s) of one of the two valve systems (s) 24, 25 controlled by one of the servomotors causes an equivalent closing movement of the valve or valves of the other of the two valve systems 24, 25 controlled by the other of said servomotors, and vice versa.

In summary, the regulation means advantageously makes it possible to manage the distribution of the first flow F1 between the first conduit 20 and the second conduit 21, or in other words to control the distribution of the primary flow Q1 between the secondary flow at input Q2a and tertiary flow Q3. This distribution can, as we have seen, also be advantageously managed mechanically with a single servomotor controlling all of the regulating means 23 and in particular the first and second valve systems 24, 25, that managed electronically, each of the first and second valve systems 24, 25 being controlled by a separate servomotor.

Preferably, the burner 32 can operate according to different operating modes. Thus, the burner 32 advantageously has different power levels.

In particular, the burner 32 has a maximum power level where it uses substantially all, or 100%, of its maximum power, and requires, in order to operate, a maximum flow of oxidizing air having a maximum oxidizing flow rate Qcmax which is for example equal to around 28,000 m ³ / h.

Preferably, the burner 32 has at least one intermediate power level where it uses a fraction of its maximum power, and requires, to operate, an intermediate oxidant air flow having an intermediate oxidant flow rate Qcint.

Advantageously, the burner 32 has a first intermediate power level where it uses a first fraction, for example 20%, of its maximum power, and where it advantageously requires, in order to operate, that the intermediate oxidant flow rate Qcint is substantially equal at the first fraction multiplied by the maximum oxidizer flow rate Qçmax, ie for example at 20% of 28,000 m ³ / h = 5,600 m ³ / h.

Preferably, the burner 32 has a second intermediate power level where it uses a second fraction, for example 50%, of its maximum power, and where it advantageously requires, in order to operate, that the intermediate oxidant flow rate Qcint is substantially equal at the second fraction multiplied by the maximum oxidizer flow rate Qc _m ax, ie for example at 50% of 28,000 m ³ / h = 14,000 m ³ / h.

Advantageously, the burner 32 of the invention is a proportional burner, that is to say that it is designed to operate according to fully adjustable operating modes, to allow the power used by the burner 32 to be adjusted as desired. over a continuous range of operating points. Thus, the burner 32 can advantageously operate according to an infinity of operating points each corresponding to a fraction of the maximum power of the burner 32. Preferably, the oxidant flow rate (intermediate Qcjnt or maximum Qc _max ) necessary for the proper operation of the burner 32 is proportional to the power used of the burner 32, the latter being therefore advantageously chosen, that is to say adjustable (between 0 and 100% of the maximum power of the burner 32), and not relative to a fixed or predetermined power level , although it is also quite possible that the burner 32 has determined preferred power levels while remaining adjustable if necessary.

Advantageously, below a threshold power level of the burner 32, the regulating means 23 adjusts the secondary flow at input Q2a as a function of the power level of the burner 32. Thus, advantageously, below the power threshold level , the regulating means 23 adjusts the secondary flow at input Q2a so that it is substantially equal to the flow of intermediate oxidizer Qcint, the flow of intermediate oxidant air being advantageously also formed by the second flow F2.

Advantageously, the power threshold level is an intermediate power level of the burner 32 where the latter uses a fraction, for example 65%, of its maximum power, and where the burner 32 advantageously requires, in order to operate, that the flow of intermediate oxidizer Qcjnt is substantially equal to the primary flow Q1, and also preferably equal to said fraction multiplied by the maximum oxidizer flow Qc _max , or for example at 65% of 28,000 m ³ / h = 22,400 m ³ / h.

The threshold power level of the burner 32 is for example greater than the first and second intermediate power levels.

Preferably, below the threshold power level of the burner 32, the regulating means 23 also adjusts the tertiary flow Q3 as a function of the power level of the burner 32, and / or as a function of the secondary flow at input Q2a.

Advantageously, the primary flow Q1 is intended to remain, whatever the power level of the burner 32, substantially constant, for example equal to 18,200 m ³ / h.

Preferably, at the first intermediate power level, which is therefore lower than the power threshold level, the regulating means 23 adjusts on the one hand the secondary flow at input Q2a so that it is substantially equal to the flow at intermediate oxidant QCint necessary for the operation of burner 32 at the first intermediate power level, the secondary flow at inlet Q2a then being for example equal to 5,600 m ³ / h, and on the other hand the tertiary flow Q3 so that 'it is equal to the primary flow Q1 from which the secondary flow at input Q2a has been' withdrawn ', the tertiary flow Q3 then being for example equal to Q1 - Q2a = 18,200 - 5,600 = 12,600 m ³ / h.

Thus, according to this last example, when the burner 32 operates below the power threshold level, that is to say below a fraction, for example 65%, of its maximum power, the regulating means 23 adjusts advantageously the secondary flow rate Q2a substantially proportional to the power level of the burner 32. In particular, when the burner 32 operates below the power threshold level, the regulating means 23 will adjust the secondary flow rate at the input Q2a so that it is substantially equal to the necessary oxidant air flow for the burner 32 to produce said flame 4, that is to say the intermediate oxidant flow Qcint, the second flow F2 then preferably having the same flow downstream and upstream of the first pipe 20 and upstream and downstream of the oxidant supply pipe 38. Thus, below the power threshold level, an increase (or a decrease) in the power of the burner r 32 results in an increase (or respectively a decrease) in the secondary flow at input Q2a by the regulating means 23. In this operating mode of the burner 32 below the power threshold level, the tertiary flow Q3 is preferably not zero, and the third flow F3 flows to the furnace 2 via the second conduit 21, entraining therein a portion of the bitumen vapors and / or dusts collected (for example the second portion). In other words, when the burner 32 operates at a power level below the threshold power level, like the first and second intermediate power levels, the first flow F1 preferably leaves the collecting means 6 to be distributed between the second stream F2 and the third stream F3, said second stream F2 and the third stream F3 each having a flow rate which is advantageously non-zero. Such a configuration, where the regulating means 23 adapts the secondary input flow Q2a and tertiary Q3 relative to the operating power of the burner 32, is particularly advantageous, because whatever the power level of the burner 32 (below of the threshold level), the burner 32 (and by extension the coating plant to which it is adapted) is intended to burn, that is to say destroy by means of combustion, at least some of the vapors and / or dust collected (except obviously if the power used of the burner 32 is zero), and this without negative impact on the production capacity of bituminous mixes at plant 1.

Preferably, at the power threshold level of the burner 32 and / or beyond, the regulating means 23 adjusts the secondary flow at input Q2a so that it is substantially equal to the primary flow Q1 and / or constant, said flow tertiary Q3 being substantially zero. For example, at the threshold power level of the burner 32 and / or beyond, the first valve system (s) 24 is in a maximum open position, while the second valve system (s) 25 is in the closed position. maximum, the secondary flow at inlet Q2a then being maximum (and substantially constant and / or equal to the primary flow Q1. ie for example 18,200 m ³ / h) and the tertiary flow Q3 then being minimum (preferably substantially zero). In the latter case, the whole of the first flow F1 within the collection means 6 circulates until advantageously forming the whole of the second flow F2 within the first conduit 20.

Advantageously, and as illustrated in the figures, said means for establishing a second and / or a third gas flow F2, F3 further comprises a secondary ventilation means 26 of said first conduit 20 and / or said conduit of oxidant 38, said secondary ventilation means 26 being intended to equip said first duct 20 and / or said oxidant supply pipe 38, and preferably positioned downstream of said collecting means 6 and / or downstream of said regulation means 23 (more particularly downstream of the first valve system (s) 24). In other words, the secondary ventilation means 26 advantageously equips said first duct 20 and / or said oxidant supply pipe 38.

Preferably, said secondary ventilation means 26 is designed to circulate (therefore set in motion) the air at least within the first duct 20 and / or said oxidant supply pipe 38, intermittently or continuously according to the power level of the burner 32, in particular by drawing outside or conditioned air and / or by setting in motion the polluted air (that is to say loaded with collected bitumen vapors and / or dusts), more preferably by combining the two actions.

Preferably, said secondary ventilation means 26 is designed to circulate (therefore set in motion) the air at least within the first duct 20 and / or said oxidant supply pipe 38, intermittently or continuously according to the power level of the burner 32, in particular by drawing outside or conditioned air which it injects into the first conduit 20 and / or said oxidant supply line 38 and / or by setting the air in motion polluted (that is to say loaded with collected bitumen vapors and / or dust), more preferably by combining the two actions.

Preferably, said secondary flow at outlet Q2b comprises the entire air flow at the outlet or just before the outlet of the oxidant supply line 38, more preferably the entire air flow in a downstream part of the oxidizer supply line 38, and even more preferably the entire air flow rate in a portion located at or just before the burner head 3.

In a particularly preferred manner, beyond the threshold power level of the burner 32, said secondary ventilation means 26 adjusts the secondary flow rate at output Q2b as a function of the power level of the burner 32. In other words, beyond the power threshold level, said secondary ventilation means 26 introduces (that is to say injects) advantageously a flow of outside or conditioned air F ^ t within the first duct 20 and / or the oxidant supply pipe 38 in order to allow correct operation of the burner 32 and in particular the production of said flame 4 by the burner 32. Preferably, the flow of outside or conditioned air F _ex t has a flow of outside or conditioned air Qext, and is intended to integrate the second flow F2 (that is to say to become a part, a component). Thus, in a particularly advantageous manner, the secondary flow at outlet Q2b is substantially equal to the addition of the secondary flow at inlet Q2a and the flow of outside or conditioned air Q ^. In other words, the burner 32 advantageously comprises within it a flow of oxidizing air to produce said flame 4 which is substantially equal:

- either at the secondary flow at input Q2a alone, in particular when the burner 32 is operating below or at the power threshold level,

- either by adding the secondary flow at input Q2a and the flow of outside or conditioned air Qg ^ in particular when the burner 32 is operating above the power threshold level,

- Either at the outside or conditioned air flow rate Q _g xt alone, in particular in the case where the collecting means 6 and / or the primary ventilation means 22 is / are defective and / or under maintenance.

Thus, advantageously, the burner 32 of the invention can operate continuously regardless of the state of the coating plant 1.

In particular, when the burner 32 operates beyond the power threshold level, the secondary ventilation means 26 will adjust the secondary flow at output Q2b so that it is substantially equal (or alternatively greater) to the flow of necessary oxidant air for the burner 32 to produce said flame 4, the second flow F2 then having different flow rates downstream and upstream of the first (the secondary flow at inlet Q2a then being less than the secondary flow at outlet Q2b). More precisely, when the burner 32 operates beyond the power threshold level, the secondary ventilation means 26 preferably adjusts the flow of outside or conditioned air Qext as a variable component of the secondary flow at output Q2b, so that the secondary flow at outlet Q2b is substantially equal (or alternatively greater) to the air flow required for oxidant for the burner 32 to function correctly, the component secondary flow at inlet Q2a of the secondary flow at outlet Q2b advantageously remaining constant.

Thus, advantageously, beyond the threshold power level of the burner 32, that is to say for example above 65% of its maximum power, the secondary ventilation means 26 adjusts the secondary flow at output Q2b in proportion to the level of the burner 32, while the secondary flow at input Q2a remains constant and substantially equal to the primary flow Q1, and that the tertiary flow Q3 remains substantially zero.

Thus, beyond the power threshold level, an increase (or decrease) in the power of the burner 32 results in an increase (or respectively a decrease) in the secondary flow rate at output Q2b by the secondary ventilation means 26. In this mode of operation of the burner 32 beyond the power threshold level, the tertiary flow Q3 is preferably zero, and the third flow F3 is therefore preferably non-existent or negligible. In other words, when the burner 32 operates at a power level higher than the power threshold level, the first flow F1 preferably leaves the collecting means 6 to enter the first conduit 20 (then into the supply line oxidizer 38) where it forms the second flow F2, to which is added the flow of outside or conditioned air Fext coming from the secondary ventilation means 26 and having the flow of outside or conditioned air Qext. Such a configuration, where the secondary ventilation means 26 is adapted in particular with respect to the power of use of the burner 32, is particularly advantageous, because whatever the power used of the burner 32 (beyond the threshold level), the latter (and by extension the coating plant to which it is adapted) is capable of burning, that is to say destroying, at least part or even all of the vapors and / or dust collected, and this without impact negative on the bituminous mix production capacity of the plant 1.

Advantageously, the burner 32 thus has a third intermediate power level where it uses a third fraction, for example 80%, of its maximum power, and where it advantageously requires, in order to operate, that the intermediate oxidant flow rate Qc ^ t either substantially equal to the first fraction multiplied by the maximum oxidizer flow rate Qc _max , or for example at 80% of 28,000 m ³ / h = 22,400 m ³ / h.

The power threshold level of the burner 32 is for example lower than the third intermediate power level.

Thus, preferably, when the burner 32 is operated at a power level higher than the power threshold level, the regulating means 23 adjusts on the one hand the secondary flow at input Q2a so that it is substantially maximum and / or substantially equal to the primary flow Q1, for example at 18,200 m ³ / h, and on the other hand the tertiary flow Q3 so that it is substantially zero, while the secondary ventilation means 26 introduces a flow of outdoor or conditioned air Qext which will be added to the secondary flow at inlet Q2a within the second flow F2 to form (and adjust) the secondary flow at outlet Q2b, so that the latter is substantially equal to the oxidant flow required for the correct operation of the burner 32, and in particular equal either to the intermediate oxidant flow rate Qcint, which is for example equal to approximately 22,400 m ³ / h, or to the maximum oxidant flow rate Qcmax, which is for example equal l at around 28,000 m ³ / h. Thus, the secondary ventilation means 26 is advantageously designed to introduce (that is to say inject) the flow of outside or conditioned air Q§xt within the first duct 20 and / or the supply duct of oxidizer 38, and more advantageously upstream of the oxidant supply line 38 to supply the latter and thereafter the flame 4 with air (more preferably oxygen contained in the air, and therefore oxidizing). The flow of outside or conditioned air Qext supplied by the secondary ventilation means 26 is therefore preferably equal to the secondary flow at outlet Q2b desired (or the intermediate oxidizer flow Qcjpt required) minus the secondary flow at inlet Q2a (or the flow primary Ql), or for example equal to Q2b (or Qcint) - Q2a (or Q1) = 22,400 18,200 = 4,200 m ³ / h.

Similarly, when the burner 32 operates at a maximum power level, ie at 100% power, the flow of outside or conditioned air Qext supplied by the secondary ventilation means 26 is advantageously equal to the secondary flow at output Q2b desired (or the intermediate oxidant flow Qcint required) minus the secondary inlet flow Q2a (or the primary flow Ql), i.e. for example equal to Q2b (or Qcint) - Q2a (or Q1) = 28,000 - 18,200 = 9 800 m ³ / h.

According to a first example, the secondary fan 37 of the secondary ventilation means 26 is designed to adjust itself the primary flow rate of outside or conditioned air flow Qext, thus adjusting the secondary flow rate at outlet Q2b, and this according to the operating mode. of the burner 32 (that is to say the operating power of the burner 32) and / or according to the secondary flow at input Q2a authorized by the regulating means 23.

According to a second example, not exclusive of the previous one, the secondary ventilation means 26 comprises at least one means 33 for adjusting the flow of outside or conditioned air .Q _ext , said adjustment means 33 being advantageously distinct from the secondary fan 37 According to this last example, the secondary fan 37 is advantageously designed to allow a mode of operation at constant flow.

In other words, the secondary fan 37 advantageously has at least one operating mode in which it extracts a constant air flow from an external source to inject it into the first duct 20 and / or the supply duct of oxidizer 38, the adjustment means 33 making it possible to vary the flow of outside or conditioned air Qext actually introduced into the first duct 20.

Preferably, said adjustment means 33 comprises a third valve system (s) 34, which comprises for example at least one valve or a plurality of valves, said valves being in particular of the butterfly type. Of course, said valves can possibly be assimilated to shutters. Preferably, said adjustment means 33 (and more precisely said third valve system (s) 34) is substantially positioned between the secondary fan 37 on the one hand and the first duct 20 and / or the supply duct of oxidant 38 on the other hand, and more precisely at the interface of the latter.

Thus, the secondary ventilation means 26, and more precisely the secondary fan 37, advantageously has at least one operating mode in which it extracts a constant flow of air from an external source to inject it into the first duct 20 and / or the oxidant supply line 38, the adjustment means 33 making it possible to vary the flow of outside or conditioned air Qext actually introduced into the first duct 20 and / or the oxidant supply line 38.

Thus, according to the second example above, the adjustment means 33 is designed to adjust itself the flow of outside or conditioned air Qext (supplied by the secondary ventilation means 26 which ventilates at constant flow or not) according to the operating mode of the burner 32 (that is to say the operating power of the burner 32) and / or the secondary flow at input Q2a authorized by the regulating means 23. In particular, the third valve system (s ) 34 is designed to limit the primary flow rate of external or conditioned air Qext to a fraction of the flow of air extracted from an external source by the secondary fan 37.

Optionally, as illustrated in FIG. 2, the collection means 6 comprises a collection regulation means 27, preferably upstream of the primary ventilation means 22, and for example formed by one or more valve system (s) 28, 29, 30, within (that is to say inside) one or more of said collection conduits 12, 13, 14, 15, said collection control means 27 being designed to regulate, it that is to say, limit, the collection of vapors and / or dust originating for example from the bitumen storage means 7, from the bituminous mix storage means 8, from the discharge zone 9, and / or from the manufacturing means bituminous mixes.

FIG. 4 illustrates an example of a burner 32 according to the invention where the first valve system 24 is in the fully open position and the second and third valve systems 25, 34 are in the fully closed position, the tertiary flow of the third flow F3 being therefore zero, while the secondary flow at input Q2a is substantially equal to the secondary flow at output Q2b, and that the flow of outside or conditioned air Qext of the flow of outside or conditioned air Fext is zero. Such a configuration, given by way of illustrative and nonlimiting example, is suitable in the case where the burner 32 operates at the power threshold level, for example at 65% of its power.

The invention also relates as such, according to a second aspect, a coating plant 1 for the manufacture of hot bituminous mixes from aggregates and bitumen, said plant 1 comprising an oven 2 and being characterized in that that it further comprises at least one burner 32 as described above (and possibly as described below), said burner 32 advantageously fitted to said oven 2. The above description concerning the burner 32 therefore also applies to the coating plant 1 according to the invention.

The invention also relates as such, according to a third aspect, a method for depolluting a coating plant 1 intended for manufacturing hot bituminous mixes from aggregates and bitumen, the depollution method preferably being implemented in the coating plant 1 described above, and / or using the burner 32 (advantageously fitted to the plant 1, and in particular the oven 2 thereof) previously described. The above description concerning the burner 32 and / or the coating plant 1 therefore also applies to the depollution process according to the invention.

The depollution process advantageously makes it possible to limit or even completely avoid the discharges of bitumen vapors and / or dust, or blue smoke, into the atmosphere, in particular by organizing their destruction by burning within the coating plant 1 .

Thus, according to the invention, said power station 1 comprises an oven 2, preferably as described above. Still according to the invention, the depollution method comprises at least one step of equipping said oven 2 with a burner 32, the latter advantageously being as described above, that is to say that it comprises a burner head 3 and an oxidant supply line 38 to the burner head 3 to produce a flame 4 at the level of the latter intended to heat the interior of said furnace 2.

Advantageously, said method comprises at least one step of collecting bitumen vapors and / or dust from the bitumen used by the plant 1 and / or bituminous mixes manufactured by the latter. Preferably, said collection step is carried out with a collection means 6, which is preferably as described above.

Still according to the invention, the depollution method further comprises a step of supplying the oxidant supply line 38 upstream of the burner head 3, with bitumen vapors and / or dust from the bitumen used by the power plant 1 and / or bituminous mixes manufactured by the latter, said bitumen vapors and / or dust having previously been advantageously collected during said collection step. Thus, preferably, during said step of supplying the oxidant supply line 38, at least part, or even all, of the bitumen vapors and / or dusts (for example formed by the first portion) from from the power plant 1 (and having been collected), is introduced into the oxidant supply line 38, so as to be burnt by the flame 4 preferably at the same time as and with the oxidant formed by the air ( and preferably the oxygen contained in the air) mixed with said bitumen vapor and / or dust.

Still according to the invention, said method also comprises a step of conveying bitumen vapors and / or dusts originating from the bitumen used by the plant 1 and / or bituminous mixes produced by the latter in the furnace 2, said vapors and / or bitumen dust having previously been advantageously collected during said collection step. Thus, during said routing step, at least a portion (not zero or zero depending on the operating mode of the burner 32, for example formed by the second portion) of the bitumen vapors and / or dusts originating from the plant 1 ( and having been collected), is advantageously introduced directly into (that is to say inside) the furnace 2 without passing through the oxidant supply line 38. Preferably, during said conveying step , at least a portion of the bitumen vapors and / or dusts collected is conveyed, that is to say transferred or displaced, in a flame 4 produced by the burner 32, as previously described.

Preferably, said supply and routing steps are carried out respectively via at least a first and a second conduit 20, 21, which are advantageously as described above. The step of supplying the oxidant supply pipe 38 with collected bitumen vapors and / or dust advantageously comprises the introduction (that is to say the transfer) of bitumen vapors and / or dust being within the first conduit 20 inside said oxidant supply line 38, said bitumen vapors and / or dusts passing from the first conduit 20 to the oxidant supply line 38 together with the air ( more preferentially the oxygen contained in the air) with which they are mixed and which will serve as oxidant to the flame 4.

The method advantageously comprises a step of establishing a second and / or a third gas flow F2, F3, preferably as described above, for circulating the bitumen vapors and / or dusts respectively during said said feeding and / or routing steps.

Preferably, said step of establishing a second and / or a third gas flow F2, F3 comprises at least one primary step of ventilating said first duct 20 (and therefore by extension, also preferably of the supply pipe oxidizer 38) and / or said second duct 21, as well as advantageously of said collecting means 6. Said primary ventilation step is preferably carried out with at least one primary ventilation means 22, as described above, the latter being by example positioned upstream of said first and second conduits 20, 21 (and therefore also upstream of the oxidant supply pipe 38).

Preferably, during the step of establishing a second and / or a third gas flow F2, F3, a first gas flow F1 is also established, the latter supplying upstream said second gas flow F2 and / or said third gas stream F3. The first gas flow F1 is advantageously located upstream from said second and third gas flows F2, F3, said second and third gas flows F2, F3 preferably being neither downstream nor upstream from each other.

Advantageously, said first gas flow F1 has a primary flow 01, as described above, for example within the collecting means 6. More advantageously still, during said primary ventilation step, said primary flow Q1 is kept substantially constant , as described above, this in particular to allow continuous collection of the bitumen vapors and / or dust from the plant 1.

Preferably, as described above, said second flow F2 has a secondary flow F2 at the inlet Q2a of said first conduit 20 and said third flow F3 has a tertiary flow Q3 within said second conduit 21. More preferably still, the method comprises a step regulating said secondary flow at input Q2a and said tertiary flow Q3.

Preferably, said regulation step is carried out with a regulation means 23, as described above, which comprises for example a first and a second valve system (s) 24, 25 respectively equipping said first and second conduits 20, 21, as previously described. Of course, said valves can possibly be assimilated to shutters. Alternatively, the first valve system 24 rather equips the oxidant supply line 38.

Advantageously, during said regulating step, said secondary flow at inlet Q2a and said tertiary flow Q3 are interdependent, in particular with the aid of regulation means 23, so that a reduction in secondary flow at inlet Q2a results in a substantially proportional increase in said tertiary flow Q3 and vice versa.

Advantageously, the burner 32 has different power levels. In particular, below a threshold power level of the burner 32, during said regulation step, the secondary flow rate at input Q2a is adjusted as a function of the power level of the burner 32, preferably using the means of regulation 23. This operating mode of the burner 32 corresponds in particular to the power levels of the latter where the primary ventilation means 22 circulates the first gaseous flow F1 whose primary flow Q1 is greater than the requirements for combustion of the burner 32.

Preferably, at the power threshold level of the burner 32 and / or beyond, during said regulation step, the secondary flow rate Q2a is adjusted (preferably using the regulation means 23) so as to this being substantially equal to the primary flow Q1 and / or constant, said tertiary flow Q3 being substantially zero.

Advantageously, said step of establishing a second and / or a third gas flow F2, F3 further comprises a secondary step of ventilating said first duct 20 and / or said oxidant supply pipe 38, said secondary ventilation step being advantageously carried out with secondary ventilation means 26, as described above, and which is preferably intended to be positioned downstream of said collecting means 6, said regulating means 23, and / or said means of primary ventilation 22.

Preferably, during said secondary ventilation step, a flow of outside or conditioned air Fext, as described above, is introduced (that is to say injected) into the first duct 20 and / or the duct of oxidant 38, in particular using the secondary ventilation means 26 which advantageously comprises a secondary fan 37 preferably of the centrifugal type. Said outside or conditioned air flow Fext advantageously has an outside or conditioned air flow Qext as mentioned above.

Advantageously, said second flow F2 has a secondary flow at the outlet Q2b of said oxidant supply pipe 38, as described above. Even more advantageously, beyond the power threshold level of the burner 32, during said secondary ventilation step, the secondary flow rate at output Q2b is adjusted, preferably by means of secondary ventilation means 26 of the power level of the burner 32. More preferably still, beyond the power threshold level of the burner 32, during said secondary ventilation step, the flow rate is adjusted, preferably using the secondary ventilation means 26 outside or conditioned air Q ^ t as a function of the power level of the burner 32, the outside or conditioned air flow Q ^ t here forming a variable component of the secondary flow at outlet Q2b, the secondary flow at inlet Q2a forming here another constant component of the secondary flow at outlet Q2b, the adjustment of the flow of outside or conditioned air Qext making it possible to adjust in practice the secondary flow at outlet Q2b. This operating mode of the burner 32 corresponds in particular to the power levels of the latter where the primary ventilation means 22 puts into circulation the first gaseous flow F1 whose primary flow Q1 is less than the requirements for combustion of the burner 32, the means of secondary ventilation 26 making it possible to supply the “missing” gas flow to allow the burner 32 to produce combustion with sufficient oxidizer (and therefore to produce the flame 4 satisfactorily).

Advantageously, the method of the invention is implemented continuously, and several (or even all) of the steps of the method are carried out concomitantly with different fractions of bitumen vapors and / or dusts.

Such a configuration has in particular the advantage of ensuring continuous and regular collection or extraction of the bitumen vapors and / or dusts originating from the plant 1 (and more specifically from the collection points). For example, said primary ventilation means 22 is designed to “extract” continuously and at a constant primary flow rate Q1 the air loaded with blue smoke outside the bituminous mix storage means 8, the bitumen storage means 7, the discharge zone 9 for bituminous mixes, and / or the means for manufacturing bituminous mixes, in order to bring at least part of it (the first portion) to the oxidant supply line 38 via the first line 20 and / or at least one other part (the second portion) directly in the oven 2 via the second conduit 21.

The principle of the invention resides in short in the adaptability of the burner 32 fitted to the coating plant 1, the burner 32 forming a burning system adjusting to burn the blue fumes from the plant 1 whatever the power of use of the burner 32, and therefore the production speed of the plant 1 and / or that of its 5 blue smokes. Indeed, at low power of use of the burner 32, in particular at the power threshold level and below, the extraction, the collection and / or the continuous and constant ventilation of the blue smoke is preferably carried out using the sole primary ventilation means 22 towards the burner 32, which can therefore burn at least a portion of the blue smoke while it injects the other portion directly into the furnace 2, and at higher power, in particular beyond the threshold level of power, the secondary ventilation means 26 adds to the air circuit sufficient gas flow (the flow of outside or conditioned air F ^) to ensure the supply of oxidant to burner 32 and therefore satisfactory or even complete combustion of the oxidant , fuel and blue smoke.

In general and particularly advantageous, in the description above, the terms of the type "primary", "secondary", "tertiary", "quaternary", etc. are simply intended to distinguish the elements concerned and have no ordinal connotation.

Claims (25)

1. Burner (32) for equipping an oven (2) with a coating plant (1) intended for manufacturing hot bituminous mixes from aggregates and bitumen, said burner (32) comprising at least one burner (3) and an oxidant supply line (38) to the burner head (3) to produce a flame (4) at the latter for heating the interior of said oven (2), the burner ( 32) being characterized in that it further comprises at least: - A first conduit (20) intended to be connected to the oxidant supply line (38) upstream of the burner head (3) to supply said oxidant supply line (38) with vapors and / or dust bitumen from bitumen used by the plant (1) and / or bituminous mixes manufactured by the latter, and - A second conduit (21) intended to lead into said oven (2) to bring into the latter vapors and / or dust of bitumen from the bitumen used by the plant (1) and / or bituminous mixes produced by the latter. 2. Burner (32) according to the preceding claim, characterized in that it comprises means for establishing a second and / or a third gas flow (F2, F3) for circulating the vapors and / or bitumen dust within said first conduit (20) and / or said second conduit (21) respectively. 3. Burner (32) according to the preceding claim, characterized in that said means for establishing a second and / or a third gas flow (F2, F3) comprises at least one primary ventilation means (22) of said first duct (20) and / or of said second duct (21), said primary ventilation means (22) being positioned upstream of said first and second ducts (20, 21). 4. Burner (32) according to the preceding claim or claim 2, characterized in that said means for establishing a second and / or a third gas flow (F2, F3) also makes it possible to establish a first flow gaseous (F1) supplying upstream said second gas flow (F2) and / or said third gas flow (F3). 5. Burner (32) according to the preceding claim dependent on claim 3, characterized in that said first gas flow (F1) has a primary flow (Q1), and in that said primary ventilation means (22) is designed to maintain said primary flow (Q1) substantially constant. 6. Burner (32) according to one of claims 2 to 5, characterized in that said second flow (F2) has a secondary flow at the inlet (Q2a) of said first conduit (20), said third flow (F3) having a tertiary flow (Q3) within said second duct (21), and in that the burner (32) comprises means (23) for regulating said secondary inlet flow (Q2a) and said tertiary flow (Q3). 7. Burner (32) according to the preceding claim, characterized in that said regulating means (23) controls said secondary flow at inlet (Q2a) and said tertiary flow (Q3) in interdependence, so that a reduction in secondary flow at the inlet (Q2a) causes a substantially proportional increase in said tertiary flow (Q3) and vice versa. 8. Burner (32) according to claim 6 or 7, characterized in that said regulating means (23) comprises a first and a second valve system (s) (24, 25) respectively equipping said first and second conduits (20 , 21). 9. Burner (32) according to one of claims 6 to 8, characterized in that it has different power levels, and in that below a threshold power level of the burner (32), the means regulator (23) adjusts the secondary input flow (Q2a) according to the power level of the burner (32). 10. Burner (32) according to the preceding claim and claim 5, characterized in that at the burner power threshold level (32) and / or beyond, the regulating means (23) adjusts the secondary flow at the input (Q2a) so that it is substantially equal to the primary flow (Q1) and / or constant, said tertiary flow (Q3) being substantially zero. 11. Burner (32) according to one of claims 2 to 10, characterized in that said means for establishing a second and / or a third gas flow (F2, F3) further comprises ventilation means secondary (26) of said first duct (20) and / or of said oxidant supply pipe (38), said secondary ventilation means (26) being intended to equip said first duct (20) and / or said supply pipe oxidizer supply (38). 12. Burner (32) according to the preceding claim and claim 9 or 10, characterized in that said second flow (F2) has a secondary flow at the outlet (Q2b) of said supply line by oxidant (38), and in that beyond the threshold power level of the burner (32), said secondary ventilation means (26) adjusts the secondary output flow (Q2b) as a function of the power level of the burner (32). 13. Coating plant (1) for the manufacture of hot bituminous mixes from aggregates and bitumen, said plant (1) comprising an oven (2) and being characterized in that it further comprises at least a burner (32) according to any one of the preceding claims. 14. Method for depolluting a coating plant (1) intended for manufacturing hot bituminous mixes from aggregates and bitumen, said plant (1) comprising an oven (2), said method comprising at least: a step of equipping said furnace (2) with a burner (32) comprising a burner head (3) and an oxidant supply pipe (38) to the burner head (3) to produce at this level last a flame (4) intended to heat the interior of said oven (2), said method being characterized in that it further comprises a step of supplying the oxidant supply pipe (38), upstream of the burner head (3), with bitumen vapors and / or dusts originating from the bitumen used by the power station (1) and / or bituminous mixes manufactured by the latter, and - A step of conveying bitumen vapors and / or dust from the bitumen used by the plant (1) and / or bituminous mixes produced by the latter in the furnace (2). 15. depollution method according to the preceding claim, characterized in that it comprises a step of establishing a second and / or a third gas flow (F2, F3) to circulate the vapors and / or dust bitumen respectively during said supply and / or routing steps. 16. depollution method according to the preceding claim, characterized in that said routing and feeding steps are carried out respectively via at least a first and a second conduit (20, 21), and in that said establishment step a second and / or a third gas stream (F2, F3) comprises at least one primary step of ventilating said first duct (20) and / or said second duct (21). 17. depollution method according to claim 15 or 16, characterized in that during the step of establishing a second and / or a third gas flow (F2, F3), a first gas flow (F1) is also established, the latter supplying upstream said second gas stream (F2) and / or said third gas stream (F3). 18. depollution method according to the preceding claim, characterized in that said first gas flow (F1) has a primary flow (Q1), and in that during said primary ventilation step, said primary flow (Q1) is maintained substantially constant. 19. depollution method according to claim 16 and optionally claim 17 or 18, characterized in that said second flow (F2) has a secondary flow at inlet (Q2a) of said first conduit (20), said third flow (F3) having a tertiary flow (Q3) within said second conduit (21), and in that the method comprises a step of regulating said secondary flow at inlet (Q2a) and said tertiary flow (Q3). 20. Depollution method according to the preceding claim, characterized in that during said regulation step, said secondary flow at the inlet (Q2a) and said tertiary flow (Q3) are interdependent, so that a reduction in the secondary flow at the inlet (Q2a) causes a substantially proportional increase in said tertiary flow (Q3) and vice versa. 21. depollution method according to claim 19 or 20, characterized in that said regulating step is carried out with regulating means (23), which comprises a first and a second valve system (s) (24, 25) equipping said first and second conduits (20, 21) respectively. 22. Pollution control method according to one of claims 19 to 21, characterized in that the burner (32) has different power levels, and in that below a threshold power level of the burner (32), during said regulation step, the secondary input flow is adjusted (Q2a) as a function of the power level of the burner (32). 23. depollution method according to claims 18 and 22, characterized in that at the threshold power level of the burner (32) and / or beyond, during said regulation step, the secondary flow rate is adjusted at the inlet (Q2a ) so that it is substantially equal to the primary flow (Q1) and / or constant, said tertiary flow (Q3) being substantially zero. 24. depollution method according to claim 15 and optionally one of claims 16 to 23, characterized in that said step of establishing a second and / or a third gas stream (F2, F3) further comprises a secondary step of ventilating said first conduit (20) and / or said oxidant supply conduit (38). 25. depollution method according to the preceding claim and claim 22, characterized in that said second flow (F2) has a secondary flow at the outlet (Q2b) of said oxidant supply pipe (38), and in that beyond the threshold power level of the burner (32), during said secondary ventilation step, the secondary output flow (Q2b) is adjusted as a function of the power level of the burner (32).