WO2015104584A1

WO2015104584A1 - Burner with adjustable dispensing means

Info

Publication number: WO2015104584A1
Application number: PCT/IB2014/058154
Authority: WO
Inventors: Benfenati ALBERTO
Original assignee: Alberto Benfenati
Priority date: 2014-01-09
Filing date: 2014-01-09
Publication date: 2015-07-16
Also published as: EP3092442A1; BR112016015858A2

Abstract

A burner comprising: - a supporting body defining at least a first duct for the transit of a combustive fluid and at least a second duct for the transit of a combustion fluid; - a combustion head associated with said supporting body and comprising diffusing means, communicating with said first duct and having a plurality of through openings for the transit of the combustive fluid towards a combustion area, and dispensing means (11) of the combustion fluid, communicating with said second duct and having a plurality of gaps for the transit of the combustion fluid itself towards said combustion area; wherein said dispensing means (11) comprise at least a fixed portion (11a) and a mobile portion (11b), where one of said fixed portion (11a) and said mobile portion (11b) defines said transit gaps (18) that are communicating with at least one dispensing channel (23) delimited by at least two opposite surfaces (24a, 24b) defined by said fixed portion (11a) and by said mobile portion (11b) respectively, the position of said mobile portion (11b) with respect to said fixed portion (11a) being adjustable to change the section of said dispensing channel (23).

Description

BURNER WITH ADJUSTABLE DISPENSING MEANS

Technical Field

The present invention relates to a burner usable in both the industrial and civil field.

Background Art

Burners are used e.g. in the ceramic industry, inside the equipment for the heat treatment of ceramic products, such as kilns and dryers.

The burners of known type are generally made of a supporting body, defining an air supply duct and a combustion gas supply duct, and of a combustion head through which the above-mentioned ducts are placed in coimnunication with a combustion area.

The combustion head in turn comprises an air diffuser, which has a plurality of openings communicating with the air supply duct to direct same towards the combustion area, and gas dispensing means, which have a plurality of transit gaps communicating with the gas supply duct to convey same towards the combustion area.

In the combustion area therefore the air is mixed with the combustion gas.

The diffuser of the combustion head generally consists of a plate-shaped element having a circular conformation, which is fitted around the gas supply duct and the entire thickness of which is crossed by the above openings.

The diffuser generally has a plurality of circular through holes, arranged along at least a circumference and having respective axes inclined so as to converge towards the extension of the longitudinal axis of the gas supply duct along the combustion area.

The diffuser also envisages a plurality of cuts obtained on its periphery according to planes inclined with respect to the longitudinal axis so as to give the air passing through it a helical movement.

The dispensing means of the burners of known type in turn have a plurality of gaps, radially directed and distributed along a circumference, to allow the combustion fluid to come out.

These burners of known type do however have a number of drawbacks.

They do not in fact permit adjusting in any way the flow rate of the combustion fluid that is dispensed towards the combustion area.

More in particular, the only way of intervening on the flow rate of combustion fluid in the burners of known type is to operate an adjusting valve located upstream of the burners themselves. It follows, therefore, that the adjustment limits are those set by the valve itself inasmuch as the burner plays no role whatsoever in such a phase.

This limit of the burners of known type is particularly evident in the limit use conditions of the burners themselves, i.e., both in maximum peaks and in production gaps (this with particular reference to the industrial field).

Another drawback of the burners of known type consists in the fact that they do not allow obtaining a perfect mix of air and combustion gas causing, especially in the case of reduced gas flow rates, the formation of unbumt materials with consequent inefficient combustion yield.

Nor do burners of known type ensure flame stability with gas flow rates close to the minimum or maximum values.

Again, known burners are unable to adapt in a flexible way to the specific requirements of the case, meaning they do not permit an effective and prompt adjustment of flame intensity according to load conditions. This means that, e.g., in the event of the flame produced by the burner being unable to satisfy the necessary heat requirements, the burner has to be replaced with another of different size. In the same way, to heat environments of different conformation or size, burners of different type must be used. All this inevitably translates into an increase in investment costs, and into more complex stock management and maintenance jobs.

Another drawback of burners of known type consists in the fact that the holes obtained in the proximity of the central seat of the diffuser tend to become dirty and blocked in time, requiring periodical maintenance and/or replacement jobs and undergoing a quick drop in performance between one job and another.

Description of the Invention

The main aim of the present invention is to provide a burner which permits adjusting the flow rate of the combustion fluid, and therefore the dispensed output, irrespective of the operating conditions of the adjustment means outside the burner and positioned upstream of same.

Within this aim, one object of the present invention is to provide a burner that is flexible to use and which allows making a broad range of combustion fluid flow rate adjustments. More in particular, with respect to burners of known type, the present invention proposes to improve operation both during maximum peaks and during production gaps.

Another object of the present invention consists in obtaining an effective mix of air and combustion gas, while at the same time ensuring high flame stability at both low and high gas flow rates.

The present invention also proposes to provide a burner which allows easily adjusting the geometry of the flame according to the specific requirements of the case.

Yet another object is to provide a burner which permits optimizing consumption with respect to burners of known type.

Not the last object of the present invention is to reduce, with respect to burners of known type, the maintenance jobs required to restore the correct operation of the diffuser and therefore substantially maintain the performance of the burner itself unaltered over time.

Another object of the present invention is to provide a burner that allows to overcome the mentioned drawbacks of the background art in the ambit of a simple, rational, easy, effective to use and low cost solution.

The objects mentioned above are achieved by the present burner comprising:

- a supporting body defining at least a first duct for the transit of a combustive fluid and at least a second duct for the transit of a combustion fluid;

- a combustion head associated with said supporting body and comprising diffusing means, communicating with said first duct and having a plurality of through openings for the transit of the combustive fluid towards a combustion area, and dispensing means of the combustion fluid, communicating with said second duct and having a plurality of gaps for the transit of the combustion fluid itself towards said combustion area; characterized by the fact that said dispensing means comprise at least a fixed portion and a mobile portion, where one of said fixed portion and said mobile portion defines said transit gaps that are communicating with at least one dispensing channel delimited by at least two opposite surfaces defined by said fixed portion and by said mobile portion respectively, the position of said mobile portion with respect to said fixed portion being adjustable to change the section of said dispensing channel.

Brief Description of the Drawings

Other characteristics and advantages of the present invention will become more evident from the description of a preferred, but not sole, embodiment of a burner, illustrated purely as an example but not limited to the annexed drawings in which:

figure 1 is an axonometric view of a burner according to the invention;

figure 2 is an enlargement of the combustion head of the burner in figure 1 ; figure 3 is a simplified view of the combustion head shown in figure 2;

figure 4 is a longitudinal section view of the burner in figure 1 ;

figure 5 is an enlargement of a detail of the cross-section in figure 4;

figure 6 is an axonometric view of the dispensing means of the combustion fluid in a first embodiment;

figure 7 is a cross-section of the dispensing means in figure 6;

figure 8 is an axonometric view of the dispensing means of the combustion fluid in a second embodiment;

figure 9 is a cross-section of the dispensing means in figure 8;

figure 10 is an axonometric view of the dispensing means of the combustion fluid in a third embodiment;

figure 1 1 is a cross-section of the dispensing means in figure 10;

figure 12 is a front view of the internal diffusing element;

figure 13 is a front view of the intermediate diffusing element;

figure 14 is a front view of the external diffusing element.

Embodiments of the Invention

With particular reference to such figures, globally indicated by reference number 1 is a burner according to the invention, usable in both the industrial and civil field.

The burner 1 comprises a supporting body 2 which defines at least a first duct 3 for the supply of a combustive fluid and at least a second duct 4 for the supply of a combustion fluid.

More in particular, the supporting body 2 comprises a first tubular element 2a defining the first duct 3 and a second tubular element 2b defining the second duct 4. By the word "tubular" used here is meant any internally hollow element, irrespective of the shape of its cross-section, which can be any.

In the embodiment shown in the illustrations, the second tubular element 2b is positioned inside the first tubular element 2a. More in particular, the first duct 3 is therefore laterally delimited by the first and by the second tubular elements 2a and 2b, while the second duct 4 is laterally delimited only by the second tubular element 2b. In the embodiment shown in the illustrations, the first duct 3 therefore extends around the second duct 4.

In the embodiment shown in the illustrations, the tubular elements 2a and 2b are substantially concentric the one with the other. The longitudinal axis of the first and of the second tubular elements 2a and 2b is identified in the illustrations by the reference letter A.

The first and the second ducts 3 and 4 have a first mouth 5 for the entry of the combustive fluid and a second mouth 6 for the entry of the combustion fluid respectively.

The supporting body 2 also defines an inlet chamber 7 communicating with the first duct 3 by means of the first mouth 5 and having an inlet mouth 8 for the combustion fluid cormectable to a ventilation system for blowing the combustive fluid, generally consisting of air.

The inlet chamber 7 is also arranged around the second tubular element 2b.

Advantageously, the inlet chamber 7 has a plurality of conveying channels 40 for conveying the combustion fluid towards the first duct 3. More in detail, such conveying channels 40 are delimited by a plurality of ribs and are suitable for directing the combustion fluid present in the inlet chamber 7 along a direction substantially parallel to the axis A of the first duct 3. The first tubular element 2a and the portion of the supporting body 2 delimiting the inlet chamber 7 can be made in a single piece or can be made separately, as in the embodiment shown in the illustrations.

The first tubular element 2a has a first extremity delimiting the first mouth 5 and a second extremity, opposite the first, connected to diffusing means 9 of the combustive fluid.

In the embodiment shown in the illustrations, the first tubular element 2a also defines the external overall dimensions of the supporting body 2, although alternative embodiments cannot be ruled out wherein the supporting body 2 also comprises a covering element of the first tubular element 2a open at one extremity and inside which the combustion head 15 is housed.

On the lateral surface of the first tubular element 2a are also defined a plurality of slots 10 distributed annularly to allow the transit of the combustive fluid from the first duct 3 towards the outside. This way, any excess combustive fluid can be released.

The second tubular element 2b also has a first extremity connected with the second mouth 6 and a second extremity, opposite the first, connected to dispensing means 1 1 of the combustion fluid.

Suitably, the second tubular element 2b comprises a union element 12 defining a section of extremity of the second duct 4. In particular, the second tubular element 2b comprises a main section 13 with which the union element 12 is associated integral. The main section 13 and the union element 12 can be made in a single body piece or separately as shown in the illustrations.

The combustion fluid is preferably in gaseous state such as natural gas.

With the supporting body 2 is associated a flange 14 suitable for enabling this to be fastened to a supporting structure.

The burner 1 then also comprises a combustion head 15 associated with the supporting body 2.

The combustion head 15 comprises the diffusing means 9 and the dispensing means 1 1.

The diffusing means 9 are communicating with the first duct 3 and have at least an opening 16 for the transit of the combustive fluid towards a combustion area 17 arranged downstream of the diffusing means themselves with respect to the air forward movement direction.

Preferably, the diffusing means 9 have a plurality of openings 16 for the transit of the combustive fluid.

The dispensing means 1 1 of the combustion fluid are communicating with the second duct 4 and have at least a gap 18 for the transit of the combustion fluid itself towards the combustion area 17. The dispensing means 1 1 are associated with the section of extremity of the second duct 4 defined in the illustrations by the union element 12.

Preferably, the dispensing means 1 1 have a plurality of gaps 18 for the transit of the combustion fluid.

Advantageously, the diffusing means 9 comprise a plurality of diffusing elements 9a,9b,9c having relative openings 16 reciprocally mobile with respect to one another to change the relative position of the openings defined on them. More in detail, at least one of the diffusing elements 9a,9b,9c can be moved with respect to the others to change the reciprocal position of the relative openings 16.

Each diffusing element 9a,9b,9c therefore has a plurality of openings 16 and by changing the reciprocal position of the diffusing elements 9a,9b,9c, the transit section of the combustive fluid is therefore changed.

It follows therefore that, combustive fluid flow rate being equal, by altering the reciprocal position of the diffusing elements 9a,9b,9c, the geometry is consequently changed of the flame produced by the burner 1. More in particular, the greater the transit section of the combustive fluid defined by the openings 16, the lower the flow resistance, hence a greater extension of the flame produced.

In the same way, by changing the reciprocal position of the diffusing elements 9a,9b,9c so as to reduce the transit section of the combustive fluid, the flow resistance is consequently increased and there is a lesser extension of the flame produced.

In other words, the flow of combustive fluid receives the minimum and the maximum deviation in the condition wherein the openings 16 define the maximum and minimum transit section respectively, following the reciprocal movement of the diffusing elements 9a,9b,9c. By changing the reciprocal position of the diffusing elements 9a,9b,9c, the deviation of the combustive fluid flow can be adjusted, a lesser deviation corresponding to a greater extension of the flame and vice versa.

Furthermore, the greater the combustion fluid transit section defined by the openings 16, the greater the maximum conductible flow rate, i.e., the output dispensable by the burner 1. In other words, by increasing the maximum flow rate of air conductible through the diffusing elements 9a,9b,9c, the maximum flow rate of gas that can be burned is also increased as is, therefore, the output of the burner 1.

More in detail, the openings 16 are defined by respective cuts 19 that extend along a portion of the relative diffusing element 9a,9b,9c starting from its perimeter edge.

In a particular embodiment, the cuts 19 are defined according to an inclined plane with respect to the plane on which the relevant diffusing element 9a,9b,9c lies.

Preferably, the openings 16 have a substantially curvilinear extension and a growing section proceeding towards the peripheral edge of the relevant diffusing element. The openings 16 thus shaped are suitable for directing the flow of combustive fluid passing through them with a helical pattern, optimizing the mix with the combustion fluid in the combustion area 17.

In the embodiment shown in the illustrations, the diffusing elements 9a,9b,9c have a substantially circular shape and the openings 16 are arranged radially on them.

The diffusing elements 9a,9b,9c are of the plate-shaped type and lie substantially orthogonal to the longitudinal axis of the tubular elements 2a and 2b.

The diffusing elements 9a,9b,9c have a central through hole 20 by means of which they are fitted around the second tubular element 2b. In particular, the diffusing elements 9a,9b,9c are fitted around the union element 12. The diffusing elements 9a,9b,9c are superimposed on one another and are reciprocally mobile around a relative rotation axis. The rotation axis of the diffusing elements 9a,9b,9c substantially coincides with the longitudinal axis A of the tubular elements 2a and 2b.

Suitably, at least one of the diffusing elements 9a,9b,9c is fixed.

More in particular, at least the innermost diffusing element 9a, i.e., that closest to the first extremity of the first tubular element 2a, is fixed with respect to the supporting body 2. As can be seen in figure 12, the through hole 20 of the fixed diffusing element 9a is not circular but shaped so as to cooperate with the union element 12 to prevent reciprocal rotation. The through hole 20 and the union element 12 have a complementary profile, i.e., they both define a pair of opposite rectilinear walls 20a which cooperate with one another to stop the diffusing element 9a in rotation with respect to the second tubular element 2b. In the preferred embodiment shown in the illustrations, the diffusing means 9 comprise three diffusing elements 9a,9b,9c superimposed on one another.

Of these three diffusing elements 9a,9b,9c two are fixed, and more particularly the innermost diffusing element 9a and the intermediate one 9b, while the diffusing element 9c facing the combustion area 17 is mobile in rotation with respect to the other two. Both the through holes 20 of the fixed diffusing elements 9a and 9b have the same profile, according to what has been described above, and are suitable for cooperating with the union element 12 around which they are fitted.

This configuration permits making the reciprocal adjustment of the diffusing elements easier, because the operator must restrict itself to regulating the position of only one of these; alternative embodiments cannot however be ruled out wherein two or more of the diffusing elements 9a,9b,9c are mobile.

Nor can alternative embodiments be ruled out comprising a greater or lesser number of diffusing elements with respect to the preferred embodiment shown in the illustrations.

The wall of the second tubular element 2b laterally delimiting the second duct 4 defines at least a locator surface 21 against which one of the diffusing elements 9a,9b,9c rests, in particular the innermost diffusing element 9a. More in detail, the locator surface 21 is defined by the union element 12 around which the diffusing elements 9a,9b,9c are fitted.

Suitably, means are provided for locking the reciprocal position of the diffusing elements 9a,9b,9c.

In the embodiment shown in the illustrations, the locking means correspond to the dispensing means 1 1 , which define a locking surface 22 intended to be rested against one of the diffusing elements 9a,9b,9c on the opposite side with respect to the locator surface 21.

The locking surface 22 is suitable for cooperating with the outermost diffusing element 9c.

The position of the dispensing means 1 1 with respect to the extremity section of the second duct 4 with which they are associated and defined in the illustrations by the union element 12, is adjustable so as to press the diffusing elements 9a,9b,9c in between the surfaces 21 and 22 the one against the other in order to prevent their reciprocal movement during use.

The dispensing means 1 1 are therefore mobile between an adjustment position, wherein they allow the reciprocal movement of the diffusing elements 9a, 9b, 9c, and a locked position, wherein they prevent the reciprocal movement of same.

More in particular, in the adjustment position, the locking surface 22 is moved away from the outermost diffusing element 9c to allow the reciprocal movement of the diffusing elements 9a,9b,9c, while in the locked position, the locking surface 22 cooperates with the outermost diffusing element 9c so as to pack up the diffusing elements themselves thereby reciprocally making them integral. In the particular embodiment shown in the illustrations, the dispensing means 1 1 can be screwed onto the second tubular element 2b in correspondence to its second extremity defined by the union element 12.

During use, the dispensing means 1 1 are therefore unscrewed to allow the adjustment of the reciprocal position of the diffusing elements 9a,9b,9c, while they are screwed up to make them reciprocally integral during the operation of the burner 1. According to the invention, the dispensing means 1 1 comprise at least a fixed portion 1 1 a and a mobile portion 1 1 b, where the position of the latter with respect to the fixed portion 1 la is adjustable.

It is best to specify that, during operation of the burner 1 , the fixed portion 1 1 a and the mobile portion l ib are integral with one another and stopped; in other words, during use, there is no relative movement between the portions 1 1 a and 1 lb, the position of the mobile portion 1 lb being changeable during the phases when the burner 1 is not used.

In particular, the fixed portion 1 la is associated with the second extremity of the second tubular element 2b, defined in the particular embodiment shown in the illustrations by the union element 12. The fixed portion 1 la is e.g. screwed onto the union element 12.

One of the fixed portion 1 1a and the mobile portion l ib defines the gaps 18 communicating with a dispensing channel 23 delimited by at least two opposite surfaces 24a and 24b defined by the fixed portion 1 la and by the mobile portion 1 lb, respectively.

Preferably, the opposite surfaces 24a and 24b, and therefore also the dispensing channel 23 defined by them, are arranged transversally to the longitudinal axis A.

As will be described in more detail below, the gaps 18 for the transit of the combustion fluid can be defined indifferently on the fixed portion 1 1 a or on the mobile portion 1 lb.

By changing the position of the mobile portion l ib with respect to the fixed portion 1 1a the reciprocal distance is consequently changed of the opposite surfaces 24a and 24b and, therefore, the transit section of the dispensing channel 23. It can be immediately appreciated how, by adjusting the position of the mobile portion 1 lb with respect to the fixed portion 1 la, it is possible to adjust the flow rate of combustion fluid towards the combustion area 17.

It follows therefore that by adjusting the position of the mobile portion 1 lb with respect to the fixed portion 1 la the output of the burner 1 is also adjusted.

In particular, the mobile portion 1 lb can be moved between at least a lowered configuration, wherein the opposite surfaces 24a and 24b are moved closer together, and a raised configuration, wherein the opposite surfaces 24a and 24b are moved away from one another with respect to the lowered configuration. As it is easy to appreciate, the transit section, and therefore the flow rate of the combustion fluid, is at minimum in the lowered configuration and at maximum in the raised configuration.

Between the lowered configuration and the raised configuration, one or more intermediate configurations are provided. It is also easy for the technician in the sector to appreciate how the reciprocal distance of the opposite surfaces 24a and 24b in the extremal configurations can vary according to the chosen embodiment. For example, in the lowered configuration, the opposite surfaces 24a and 24b can be in contact with one another or, alternatively, at a minimum predefined distance.

Suitably, the burner 1 comprises means for adjusting the position of the mobile portion 1 lb with respect to the fixed portion 1 la. In particular, the adjustment of the position of the mobile portion 1 lb can be of the discrete or continuous type. More in detail, the fixed portion 1 la has a seat 25 inside which is inserted the mobile portion l ib. Preferably, the mobile portion l ib is inserted in a removable way inside the seat 25. The mobile portion l ib is, e.g., screwed up inside the seat 25 defined on the fixed portion 1 la.

In the embodiments shown in the illustrations from 6 to 9, the adjustment means comprise at least a locator element 28, having a predefined thickness, placed between the fixed portion 1 1a and the mobile portion l ib. More in detail, the seat 25 defines an abutment surface 26 whereby it is suitable for cooperating with a respective counter-abutment surface 27 defined on the mobile portion l ib and between which the locator element 28 is placed. The locator element 28 is of the rigid type and its thickness defines the distance between the opposite surfaces 24a and 24b. More in detail, the mobile portion 1 lb is fitted inside the seat 25 until its counter-abutment surface 27 rests on the locator element 28 in turn arranged resting on the abutment surface 26. It is therefore easy to appreciate how, by changing the thickness of the locator element 28, the reciprocal position of the fixed portion 1 1a and of the mobile portion 1 lb is also consequently changed. In an alternative embodiment, shown in the figures 10 and 1 1 , the adjustment of the position of the mobile portion l ib is of the continuous type. In this embodiment, the mobile portion 1 lb is screwed up inside the seat 25 and safety means 29 are provided suitable for cooperating with the mobile portion itself to prevent its movement away from the fixed portion 1 1 a. More in particular, the safety means 29 comprise, in the embodiment shown in the illustrations, a threaded element 29 which fits through a central threaded through hole, defined on the fixed portion 1 1 a. The bottom extremity of the threaded element 29 is therefore arranged inside the seat 25.

By adjusting the position of the threaded element 29 with respect to the mobile portion 1 1 b the maximum distance is consequently defined of the latter from the fixed portion 1 la.

More in particular, by turning the mobile portion l ib with respect to the fixed portion 1 1a, the former also moves with respect to the threaded element 29. It therefore follows that the mobile portion l ib can be screwed/unscrewed with respect to the fixed portion 1 la until it reaches the extremities of the thread of the threaded element 29.

It is therefore easily to appreciate how, to move the mobile portion l ib away from the fixed portion 1 1a the threaded element 29 must be adjusted, moving it away from the mobile portion itself, after which the latter must be adjusted so as to unscrew it until the limit position is reached defined by the thread of the threaded element 29. In the same way, to move the mobile portion 1 lb closer to the fixed portion 1 1a the mobile portion itself must be screwed up with respect to the fixed portion 1 1 a, after which the threaded element 29 is screwed onto the mobile portion 1 lb so as to lock the position of the latter (i.e., so that the mobile portion l ib cannot be further unscrewed with respect to the threaded element 29).

As can be seen in detail on the attached illustrations, which represent only some of the possible embodiments, the fixed portion 1 la and the mobile portion 1 lb can take on various configurations, including considerably different the one from the other, but such as to in any case pennit adjusting the flow rate of combustion fluid towards the outside according to what has been described above.

In the embodiments shown in the figures 6, 7 and 10, 1 1 , the fixed portion 1 1 a comprises a plurality of channels 30 for the transit of the combustion fluid communicating with the second duct 4 and each defining a respective transit gap 18. The channels 30 extend along a direction substantially parallel to the second duct 4, while the gaps 18 are arranged (i.e., lie on a plane) substantially orthogonal to such parallel direction.

In this embodiment, the gaps 18 face onto the surface 24a delimiting the dispensing channel 23.

In the alternative embodiment shown in the figures 8 and 9, the mobile portion l ib has a central channel 31 communicating, through the seat 25, with the second duct 4 and along the peripheral edge of which the gaps 18 are defined. The central channel 31 is therefore substantially coaxial with the second duct 4 and the gaps 18 are arranged (i.e., lie on a plane) substantially parallel to the longitudinal axis A. In this embodiment, the fixed portion 1 1a has a circular surface 32 surrounding the section of the mobile portion l ib on which are defined the gaps 18 and which extends substantially parallel to the longitudinal axis A. More in particular, the circular surface 32 is substantially coaxial with the ducts 3 and 4.

Advantageously, in correspondence to the circular surface 32, the fixed portion 1 1a has a plurality of recesses 33, e.g., with a semi-circular shape, angularly distanced the one from the other and arranged substantially parallel to the gaps 18. These recesses 33 define the minimum flow rate of the combustion fluid in the configuration corresponding to the smaller transit section of the dispensing channel 23, i.e., wherein the surfaces 24a and 24b are in contact with each other. Preferably, the section of the mobile portion 1 1 b decreases proceeding from the second duct 4 towards the combustion area 17, as shown in the embodiment in the figures from 6 to 9.

This particular conformation of the mobile portion l ib, the section of which therefore narrows towards the longitudinal axis A proceeding outwards, permits the formation of a local depression that causes a suction effect on the combustive fluid and on the combustion fluid thereby giving rise to an effective mix of same.

More in detail, the combustion fluid exiting with whirling movement from the diffusing elements 9a, 9b and 9c and the combustion fluid exiting through the dispensing channel 23 transversally to the longitudinal axis A, are sucked up towards the combustion area 17 by effect of the variation in section of the mobile portion l ib.

The burner 1 is also equipped with an ignition electrode 34 and a combustion control sensor 35, both of traditional type and, therefore, not described in detail. The ignition electrode 34 and the control sensor 35 are arranged aligned with the longitudinal axis A and are fitted passing through the diffusing elements 9a,9b,9c within respective seats 36, ending up in correspondence to the combustion area 17.

The operation of the present invention is the following.

Before igniting the burner 1 , according to the specific requirements of the case, the operator consequently regulates the reciprocal position of the diffusing elements 9a, 9b and 9c and of the mobile portion 1 lb with respect to the fixed portion 1 1a.

The operator therefore makes the above adjustments according to a series of parameters, including the Kcal/h which the burner 1 has to produce, the size of the environment to be heated and the ideal stoichiometric ratio between air and gas.

In particular, the operator unscrews the fixed portion 1 1a from the union element 12 so as to loosen the compression force acting on the diffusing elements 9a, 9b and 9c and thus allow the adjustment of the angular position of the outennost diffusing element 9c with respect to the fixed diffusing elements 9a and 9b.

This way, as described above in detail, we intervene on the air flow section and, therefore, on the geometry of the flame produced by the burner 1.

Once the desired position of the outermost diffusing element 9c has been identified, the operator again screws the fixed portion 1 1a up to the union element 12 thus again packing up the diffusing elements 9a, 9b and 9c so as to make them reciprocally integral.

The operator then also proceeds in the same way as regards the dispensing means 1 1 , i.e., he/she changes the transit section of the dispensing channel 23 by altering the reciprocal position of the fixed portion 1 1 a and of the mobile portion l ib.

As described above, the adjustment procedure of the position of the mobile portion l ib with respect to the fixed portion 1 1 a can be of the discrete or continuous type.

In the first case, examples of which are the embodiments shown in the figures from 6 to 9, the operator removes the mobile portion 1 lb from the fixed portion 1 1 a and replaces the intermediate element 28 and fits one of different thickness. In the second case instead, shown in the figures 10 and 1 1 , the operator intervenes on the threaded element 29 and on the mobile portion 1 1 b to change the position of the latter according to what has been described above.

It has in practice been ascertained how the described invention achieves the proposed objects and in particular the fact is underlined that the burner forming the subject of the present invention, thanks to the particular structure of the combustion fluid dispensing means, allows easily and precisely changing the flow rate of such fluid towards the combustion area. This pemiits adjusting the output of the burner according to need, reducing the formation of carbon residues in the combustion area and easily adapting burner operation to both maximum peaks and to production gaps (in case of use in the industrial field, e.g., in the ceramic industry).

The burner forming the subject of the present invention also allows easily and practically adjusting the geometry, and therefore the extension, of the flame of the burner itself. This adjustment, which is made simply by altering the reciprocal position of the diffusing elements equipping the combustion head, pemiits adapting, in an extremely flexible way, the operation of the burner itself to the specific requirements of the case. More in particular, the burner forming the subject of the present invention can also be used for different conformations and sizes of the environment to be heated. This is extremely advantageous, e.g., in the ceramic industry, where the same burner can adapt itself to different widths and manage to effectively also heat the tiles in the central area of the kiln itself, thus avoiding the formation of unburnt materials.

The burner according to the invention thus makes it possible to optimize the heat phases which distinguish the ceramic process, thereby permitting a reduction in the number of firing cycles and, consequently, an increase in production per unit of time.

Claims

1 ) Burner ( 1 ) comprising:

- a supporting body (2) defining at least a first duct (3) for the transit of a combustive fluid and at least a second duct (4) for the transit of a combustion fluid;

- a combustion head (15) associated with said supporting body (2) and comprising diffusing means (9), communicating with said first duct (3) and having a plurality of through openings ( 16) for the transit of the combustive fluid towards a combustion area ( 17), and dispensing means (1 1 ) of the combustion fluid, communicating with said second duct (4) and having a plurality of gaps ( 18) for the transit of the combustion fluid itself towards said combustion area (17);

characterized by the fact that said dispensing means (1 1 ) comprise at least a fixed portion (1 1a) and a mobile portion (l ib), where one of said fixed portion (1 1a) and said mobile portion (l ib) defines said transit gaps (18) that are communicating with at least one dispensing channel (23) delimited by at least two opposite surfaces (24a, 24b) defined by said fixed portion (1 1a) and by said mobile portion (l ib) respectively, the position of said mobile portion (l ib) with respect to said fixed portion (1 1a) being adjustable to change the section of said dispensing channel (23).

2) Burner (1) according to claim 1 , characterized by the fact that the position of said mobile portion (l ib) with respect to said fixed portion ( 1 1a) is adjustable between a lowered configuration, in which said opposite surfaces (24a, 24b) are moved closer to each other, and a raised configuration, in which said opposite surfaces (24a, 24b) are moved away from one another with respect to said lowered configuration, the section of said dispensing channel (23) being minimum in said lowered configuration and maximum in the raised configuration.

3) Burner (1) according to claim 1 or 2, characterized by the fact that said dispensing channel (23) extends transversally with respect to the longitudinal extension of said second duct (4).

4) Burner (1) according to one or more of the preceding claims, characterized by the fact that it comprises adjustment means for adjusting the position of said mobile portion (l ib) with respect to said fixed portion (1 1a).

5) Burner (1) according to one or more of the preceding claims, characterized by the fact that said fixed portion (1 1a) comprises a housing seat (25) inside which said mobile portion (l ib) is inserted in a removable way.

6) Burner (1) according to claim 4 or 5, characterized by the fact that said adjustment means comprise at least a locator element (28) placed between said fixed portion (1 1a) and said mobile portion (l ib).

7) Burner ( 1 ) according to claim 4 or 5, characterized by the fact that said mobile portion (l ib) is screwed onto said fixed portion (1 1a) and by the fact that it comprises safety means (29) that are suitable for cooperating with said mobile portion (l ib) to prevent its movement away from said fixed portion (1 1a).

8) Burner (1) according to claim 7, characterized by the fact that said safety means comprise at least a threaded element (29) inserted through a through hole obtained on said mobile portion (l ib).

9) Burner ( 1) according to one or more of the preceding claims, characterized by the fact that said fixed portion ( 1 1a) comprises a plurality of channels (30) for the transit of the combustion fluid communicating with said second duct (4) and each defining a respective gap ( 18) facing on the surface (24a) that delimits said dispensing channel (23).

10) Burner (1) according to one or more of the claims from 1 to 8, characterized by the fact that said mobile portion (l ib) defines a central channel (31) communicating with said second duct (4) and defining said transit gaps (18). 1 1) Burner (1) according to claim 10, characterized by the fact that said gaps (18) are defined on the section of said mobile portion which delimits laterally said central channel (31) and which extends substantially parallel to the longitudinal axis of said second duct (4).

12) Burner ( 1 ) according to claim 1 1 , characterized by the fact that said fixed portion (1 1a) has a circular surface (32) that surrounds the section of the mobile portion ( l ib) on which are defined said gaps (18), said circular surface (32) having a plurality of recesses (33) which define the minimum flow rate of the combustion fluid with said opposite surfaces (24a, 24b) in contact with each other.

13) Burner (1) according to one or more of the preceding claims, characterized by the fact that said mobile portion (l ib) has a section which decreases as it moves close to said combustion area (17).