WO2015177735A1

WO2015177735A1 - An integrated system for regulating and mixing comburent and fuel for a burner

Info

Publication number: WO2015177735A1
Application number: PCT/IB2015/053711
Authority: WO
Inventors: Bruno Giordano
Original assignee: Idea S.P.A.
Priority date: 2014-05-23
Filing date: 2015-05-20
Publication date: 2015-11-26
Also published as: ES2749052T3; EP3146266B1; EP3146266A1

Abstract

Described is an integrated system (100) for regulating and mixing comburent and fuel for a burner, comprising a valve (1) for the fuel and ventilation means (40). These ventilation means (40) comprise a first inlet (41) for the comburent, a second inlet (54) for the fuel connected to an outlet passage of the valve (1), and an outlet connectable to the burner. Moreover, the valve (1) comprises a shutter (11) movable along a movement axis (12), between an open position, to allow the passage of the fuel, and a closed position to block the passage of the fuel. The system (100) comprises a unit (63) for detecting comburent along the first inlet (41) configured for detecting the presence of comburent in transit along the first inlet (41) and for activating the means (60) for holding in position the shutter (11).

Description

DESCRIPTION

AN INTEGRATED SYSTEM FOR REGULATING AND MIXING COMBURENT AND FUEL FOR A BURNER

TECHNICAL FIELD

This invention relates to an integrated system for regulating and mixing comburent and fuel for a burner.

More specifically, the integrated system is defined by the assembly of a valve body for the fuel and a fan for the comburent. More in detail, the integrated system according to this invention is directed to the sector of making a mixture between fuel and comburent to be fed to a burner.

More specifically, the system is dedicated to the mixing between air (as comburent) and gas (as fuel).

BACKGROUND ART

According to the prior art represented, for example, by the content of patent document US 8,596,957, the valve body extends between aniniet passage and an outlet passage for the gas. The fan comprises an inlet wherein gas and air merge and an outlet connectable to the burner. More specifically, the outlet passage of the gas is placed in fluid communication with the inlet of the fan in such a way that the latter can receive the gas to be mixed with the air.

More specifically, the valve body comprises at least one valve stage (usually two valve stages) comprising, in turn, a shutter interposed between the inlet passage and the outlet passage and movable along an axis of movement, between an open position, to allow the passage of the gas, and a closed position to block the passage of the gas.

The valve body also comprises a unit for moving the shutter operatively associated with the shutter for moving it from the closed position to the open position and vice versa.

Preferably, electromagnetic systems are used for moving the shutter. In these electromagnetic systems, the shutter is moved by an electromagnetic attraction between a ferromagnetic part, usually mounted on the shutter, and an electromagnetic circuit associated with the frame of the valve.

In that way, when the system is activated, the fan is supplied and the shutter is opened in such a way as to make the air and gas mixture. It should be noted that, during an operating condition of the system, the shutter is kept in the open position thanks to the constant presence of the electromagnetic field.

This prior art, however, is not free of drawbacks.

More specifically, the main drawback is linked to the fact that the movement of the shutter is independent of the operation of the fan. Consequently, if the fan is stationary (for example, because it has been obstructed or due to a malfunction of the control system), the shutter could be in the open position letting gases pass which would accumulate inside the fan.

This accumulation of gas can become dangerous both for the next starting of the fan (the burner would be supplied with an excessive quantity of fuel) and for the environment in which the system is positioned since the gas might escape.

The same situation could occur if the air inlet duct or the fumes outlet duct (flue) is completely or partially obstructed. In effect, in that case, there is not a sufficient air flow rate to guarantee a correct mixing and a subsequent combustion.

Other examples of prior art systems for regulating and mixing comburent and fuel for a burner are shown in patent documents EP2442028 and US 2010/314469.

AIM OF THE INVENTION

In this situation, the aim of this invention is to provide an integrated system for regulating and mixing comburent and fuel for a burner which overcome the above-mentioned drawbacks.

In particular, the aim of this invention to provide an integrated system for regulating and mixing comburent and fuel which allows an increase in the level of safety in situations in which a sufficient flow rate of the comburent is not present.

Another aim of this invention to provide an integrated system for regulating and mixing comburent and fuel which allows safe conditions to be automatically established for the system in situations in which a sufficient flow rate of the comburent is not present.

The aims indicated are substantially achieved by an integrated system for regulating and mixing comburent and fuel as described in the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Further characteristic features and advantages of this invention will emerge more clearly from the detailed description of several preferred, but not exclusive embodiments of an integrated system for regulating and moving comburent and fuel illustrated in the accompanying drawings, in which:

- Figure 1 is an axonometric view of the integrated system according to this invention;

- Figure 2 is an axonometric view of the valve of the integrated system illustrated in Figure 1 ;

- Figure 3a is a side view of the valve illustrated in Figure 2;

- Figure 3b is a front view of a cross section of the valve of Figure 3 along the axis A-A;

- Figure 4 is an axonometric view of a cross section of the valve of Figure 3 along the axis A-A in a first operating step;

- Figure 5 is an axonometric view of a cross section of the valve of Figure 3 along the axis A-A in a second operating step;

- Figure 6 is an axonometric view of a cross section of the valve of Figure 3 along the axis A-A in a third operating step;

- Figure 7 is an axonometric view of a cross section of the valve of Figure 3 along the axis A-A in a fourth operating step;

- Figure 8 is an axonometric view of a detail of the valve illustrated i,n Figures 4, 5, 6, 7.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the accompanying drawings, the numeral 100 denotes in its entirety an integrated system 100 for regulating and mixing comburent and fuel for a burner according to the present invention.

More specifically, the system 100 comprises a valve 1 for the fuel which extends between an inlet duct 2 of the fluid and an outlet duct 3 of the fluid along a main path. This main path also defines the main direction of propagation of the fluid.

More in detail, the inlet duct 2 has a relative final part defined by an inlet passage 8. Moreover, the outlet duct 3 defines an outlet passage 80.

Moreover, the system 100 comprises ventilation means 40 preferably defined by a fan. These ventilation means 40 comprise a first inlet 41 for the comburent, a second inlet 54 for the fuel and an outlet 55 connectable to the burner for feeding to the latter the mixture of fuel and comburent. Preferably, the outlet passage 80 surrounds the first inlet 41 and the second inlet 54.

Preferably, the first inlet 41 and the second inlet 54 are defined by a opening single made on the ventilation means 40. In other words, the comburent and the fuel enter in the ventilation means 40 through the single opening.

In addition, the outlet passage of the valve 1 is connected to the second inlet 54 (or to the single opening) for the fuel in such a way as to receive the fuel passing through the valve 1.

As shown from Figure 1 , the valve 1 is directly mounted on the ventilation means 40 in such a way as to form a single body integrated with it. Preferably, the system 100 comprises removable connecting means 56 positioned between the ventilation means 40 and the valve 1 for connecting them to each other.

In detail, the removable connecting means 56 comprise a perforated flange 57 formed on an outer wall of the valve 1 , corresponding holes 58 threaded internally and made on the ventilation means 40 and joining elements 59 (preferably screws and/or bolts) partly threaded and each inserted through the perforated flange 57 and screwed in a corresponding hole.

Preferably, the perforated flange 57 has elongate holes in the form of slots in such a way as to facilitate correct positioning of the valve 1 on the ventilation means 40 for fixing irrespective of the type and/or outline of the latter.

It should be noted that the valve 1 extends between a relative bottom wall 9, and a relative top wall 10 opposite the bottom part along the axis of movement 12 described below.

In addition, the valve 1 comprises at least one valve stage in turn comprising a shutter 1 1 interposed between the inlet passage 8 and the outlet passage 80 and movable along a movement axis 12, between an open position, to allow the passage of the fuel, and a closed position to block the passage of the fuel.

In detail, the valve 1 has an opening 6 interposed between the inlet passage 8 and the outlet passage 80. More specifically, the shutter 1 1 operates at the opening 6 for allowing or blocking the transit of fuel. In other words, the shutter 1 1 is abutted against the opening 6 to close it during the closed position, and is spaced from the opening 6 during the open position.

More specifically, the opening 6 extends along a respective axis of extension 12 substantially parallel to the axis of movement 12. For this reason, for sake of simplicity, the axis of extension has been labelled with the same reference as the axis of movement 12 (numeral 12). It should be noted that the axis of extension 12 of the opening 6 is substantially transversal (preferably orthogonal) to the main part of the path relative to the inlet duct 2. In that way, for the gas to pass from the inlet duct 2 through the opening 6 it must turn through a right angle.

The valve 1 also comprises a unit 15 for moving the shutter 1 1 operatively associated with the shutter 1 1 for moving it from the closed position to the open position.

In the preferred embodiment, the movement unit 15 is a rod 16 extending between a respective operating portion 17 which can engage the shutter 1 1 for moving it and a respective drive portion 18 opposite to the operating portion 17.

It should be noted that the rod 16 is movable along the axis of movement 12 in a first direction 19 for moving the shutter 1 1 from the closed position to the open position. The first direction 19 is preferably directed towards the ventilation means 40. More specifically, the operating portion 17 of the rod 16 has a pushing end 20 facing the shutter 1 1 and able to abut against it for pushing it from the closed position to the open position.

More specifically, the rod 16 is movable from an initial position, wherein it is spaced from the shutter 1 1 along the axis of movement 12 (and the shutter 1 1 is in the closed position), to an interception position of the shutter 1 1 , wherein it is in contact with the shutter 1 1 (and the shutter is in the closed position), to an intermediate position wherein the shutter 1 1 is in the intermediate position.

In that way, the movement unit 15 pushes the shutter 1 1 from the closed position to the intermediate position.

More in detail, the shutter 1 1 comprises a plate extending at right angles to the axis of extension of the opening 6. In addition, the shutter 1 1 comprises an annular sealing gasket 14 positioned on the plate and facing the opening 6 and shaped in a fashion similar to the edge of the opening 6 in such a way as to close the passage during the closed position of the shutter 1 1. In addition, the valve 1 comprises means 42 for driving the rod 16 associated with the drive portion 18 of the rod 16. More specifically, the means 42 for driving the rod 16 are positioned in a service compartment 43 of the valve 1 made at the top wall 10.

It should be noted that the top wall 10 delimits a valve body and the service compartment 43 is positioned outside of the valve body. In an alternative embodiment not illustrated in the accompanying drawings, the service compartment 43 is inside the valve body.

More specifically, the means 42 for driving the rod 16 are configurable between a rest condition, a first operating condition and a second operating condition. During the rest condition, the first shutter 1 1 is in the closed position and the pushing end 20 of the rod 16 is spaced from the shutter 1 1. During a first operating condition, the rod 16 moves along the direction of movement 12 in the first direction 19 in such a way as to move the shutter 1 1 towards the top wall 9 (to move it from the closed position to the intermediate position).

More specifically, the drive means 42 comprise an electromagnetic element 44 to move the rod 16 along the first direction 19 or along the second direction 21. The electromagnetic element 44. is inserted inside the service compartment 43 and is associated with the drive portion 18 of the rod 16. In other words, the rod 16 passes through the bottom wall 9 10 and is partly inserted in the service compartment 43.

Still more specifically, the electromagnetic element 44 comprises a magnet 45 fixed in position relative to the rod 16 and an electromagnetic circuit 46 connected to the drive portion 18 of the rod 16. In other words, the electromagnetic circuit 46 moves relative to the magnet 45 towards or away from it. Preferably, the electromagnetic circuit 46 is movable (by moving the rod 16), depending on the direction of the electrical current, from the rest condition to the first operating condition or to the second operating condition and vice versa.

In addition, the electromagnetic circuit 46 comprises an electricity power cable 47 extending inside the service compartment 43 towards a hole put in communication between the service compartment 43 and the outside of the valve 1 for connection to an electrical power source.

The power cable 47 is positioned between the top wall 10 and the rest of the electromagnetic circuit 46 and is wound in the form of a spiral in such a way as to reduce the interference with the rest of the electromagnet circuit 46 during movement of the latter. Preferably, the electromagnetic circuit 46 is of the voice-coil type.

Moreover, the valve 1 comprises first elastic means 34 positioned between the shutter 1 1 and the bottom wall 9 of the valve 1. The first elastic means 34 are extended during the closed position of the shutter 1 1 and compressed during the open position of the shutter 1 1 in such a way as to facilitate the return of the shutter 1 1 from the open position to the closed position. Moreover, the first elastic means 34 are advantageously configured to keep the shutter 1 1 abutted against the rod 16 during the passage from the closed position to the open position. Preferably, the first elastic means 34 are positioned in contact with the shutter 1 1 at a suitable recess formed on the shutter 1 1 and which faces the bottom wall 9 of the valve 1.

In the preferred embodiment, the first elastic means 34 comprise a helical spring.

Moreover, the valve stage comprises means 60 for holding in position operatively active between a fixed portion of the valve 1 and the shutter 1 1 and which can be configured between an activation condition during which they keep the shutter 1 1 in an open position, and a deactivation position. During the activation condition, the means 60 for holding in position are configured for acting on the shutter 1 1 when the latter is in an intermediate position between the open position and the closed position.

In other words, whilst the movement unit 15 moves the shutter 1 1 from the open position to the intermediate position, the means 60 for holding in position act on the shutter when the latter is in the intermediate position to move it to the open position in such a way as to keep open the valve stage.

Preferably, the means 60 for holding in position are of the magnetic type and define a field of magnetic attraction extending from the open position 5 to the intermediate position of the shutter 1 1 .

In detail, the holding means 60 are positioned between a fixed portion and the shutter 1 1 and are configurable between an active condition and an inactive condition.

The fixed portion is preferably defined by the closing wall 9 of the valve 1 l o which delimits at the back the valve 1 relative to the shutter 1 1 .

Preferably, a first part 61 of the means 60 for holding in position is positioned at the closing wall 9 of the valve 1 whilst a second part 62 of the means 60 for holding in position is positioned at the shutter 1 1 . The shutter 1 1 is movable from the intermediate position to the open position

15 along a direction of approach to the closing wall 9.

More specifically, the first part 61 of the means 60 for holding in position comprises a magnet 37. The second part 62 of the means 60 for holding in position is incorporated the shutter. In addition, the second part 62 of the means 60 for holding in position comprises a magnet and/or ferromagnetic

20 material associated with the shutter 1 1 . Preferably, the second part 62 of the means 60 for holding in position comprises the ferromagnetic material. This magnet 37 is positioned at the closing wall 9 and the ferromagnetic material is positioned on the shutter 1 1 . As already mentioned, the ferromagnetic material could be incorporated in the shutter 1 1 .

25 In that way, the magnet 37 generates a magnetic field which involves the ferromagnetic material present in the shutter 1 1 so as to attract the shutter 1 1 towards the closing wall 9. In an alternative embodiment not illustrated in the accompanying drawings, the magnet 37 could be positioned on the shutter 1 1 whilst the ferromagnetic material and/or the magnet could be

30 positioned on the closing wall 9.

During the active condition the holding means 60 are configured for attracting the shutter 1 1 towards the closing wall 9 when the shutter 1 1 is moving from the closed position to the open position and when the distance between the shutter 1 1 and the closing wall 9 is less than the distance between the shutter 1 1 , in the closed position, and the closing wall 9. In other words, the holding means 60 are configured to act on the shutter 1 1 only after the latter has started to move from the closed position to the open position. In yet other words, the holding means 60 act when the distance between the shutter 1 1 and the closing wall 9 is less than a predetermined minimum distance. In effect, the holding means 60 are configured to generate a magnetic field which can move the shutter 1 1 only when the latter is at a distance from the closing wall 9 less than the distance between the shutter 1 1 during the rest position and the closing wall 9. The distance is the above-mentioned predetermined minimum distance.

Advantageously, this configuration of the holding means 60 makes it possible to reduce the amount of energy necessary to fully move the shutter 1 1 from the closed position to the open position, because the magnetic field generated is able to operate only at distances of less than (or at the most equal to) the predetermined minimum distance.

In other words, the holding means 60 are configured to act on the shutter 1 1 when the latter is in an intermediate position located between the open position and the closed position. This intermediate position corresponds to the above-mentioned predetermined minimum distance from the closing wall 9.

In yet other words, the movement unit 15 of the shutter 1 1 is configured for bringing the shutter 1 1 from the open position to the intermediate position. In that sense, the holding means 60 define a field of magnetic attraction extending from the opening to the intermediate position of the shutter 1 1. In other words, the field of magnetic attraction extends up to covering the intermediate position. More specifically, the field of magnetic attraction has a predetermined attractive force up to the intermediate position and not up to the closed position of the shutter.

In other words, the field of magnetic attraction is not able to move the shutter 1 1 when the latter is positioned in the closed position. In that way, it is possible to generate a magnetic field (defined by the holding means 60) having reduced intensity and, consequently, having a reduced waste of energy.

According to the invention, the system 100 comprises a unit 63 for detecting comburent along the first inlet 41 configured for detecting the presence of comburent in transit along the first inlet 41 .

Alternatively, if the first inlet 41 is joined to the second inlet 54 by the single opening, as described above, the unit 63 for detecting the comburent is positioned at the single opening.

Moreover, the system 100 comprises means for activating means 60 for holding in position operatively connected to the unit 63 for detecting the comburent and configured for activating the means 60 for holding in position when the unit 63 for detecting comburent detects the presence of comburent in transit along the first inlet 41.

In that way, when the detection unit 63 detects the transit of comburent the shutter 1 1 is kept in the open position (following the movement of the movement unit to move the shutter 1 1 from the closed position at least to the intermediate position) whilst if the detection unit 63 does not detect the transit of comburent the shutter 1 1 can not be kept in the open position and returns to the closed position.

More specifically, the detecting unit 63 comprises any apparatus which is able to detect the passage of comburent towards the ventilation means 40. In the preferred embodiment illustrated in the accompanying drawings purely by way of example, the detection unit 63 comprises a rotor 64 exposed to the comburent in transit along the first inlet 41 in such a way as to be moved by the passage of the comburent for detecting the passage of the comburent. More in detail, the rotor 64 (shown more clearly in Figure 8) rotates about a relative axis of rotation under the action of the comburent moving towards the ventilation means 40.

Preferably, the system 100 comprises a communication compartment 65 shared between the first inlet 41 , the second inlet 54 and the outlet passage and positioned between the valve 1 and the ventilation means 40. The detection unit 63 is positioned in the communication compartment 65.

Moreover, the rotor 64 is located in the proximity of the shutter 1 1. Preferably, the rotor 64 is located at a side of the closing wall 9 opposite to the position of the shutter 1 1 outside the valve 1 .

In addition, in the preferred embodiment, the means 60 for holding in position are of the magnetic type and the first part 61 and/or the second part 62 define the above-mentioned field of magnetic attraction. More specifically, the first part 61 of the means 60 for holding in position is associated with the shutter 1 1 whilst the second part 62 of the means 60 for holding in position is incorporated in the rotor 64.

Advantageously, in this way an energy saving is guaranteed thanks to the fact that the holding means 60 are configured for keeping the shutter 1 1 in the open position thanks to the presence of the field of magnetic attraction (generated on account of the passage of comburent) without further wasting electricity (due, for example, to the powering of an electromagnet as in traditional systems).

Further, the second part 62 of the means 60 for holding in position is positioned at a portion of the rotor 64 and the first part 61 of the means 60 for holding in position is positioned at a portion of shutter 1 1. In that way, the portion of rotor 64 and the portion of shutter 1 1 may be aligned with or offset from each other depending on the rotation of the rotor 64. In effect, the first part 61 and/or the second part 62 of the means 60 for holding in position is, at least partly, off centre relative to the axis of movement 12 (in the case of the first part 61 ) or relative to the axis of rotation (in the case of the second part 62).

Preferably, the axis of rotation is aligned with the axis of movement 12 and is positioned as an extension of it.

The rotor 64 is rotatable about the axis of rotation from an initial position to a final position along a predetermined angular curve.

During the initial position, the second part 62 of the holding means 60 and the first part 61 of the holding means 60 is moved relative to the field of magnetic attraction in such a way as to deactivate the means 60 for holding in position. In effect, the two parts do not attract each other magnetically.

In other words, the first part 61 of the holding means 60 and/or the second part 62 of the holding means 60 is moved relative to the field of magnetic attraction.

Preferably, the shutter 1 1 has at least one recess 66 defining a spacing relative to the second part 62. Further, the second part 62 is positioned at the recess 66 in such a way that the magnetic field made from the second part 62 does not influence the shutter 1 1 . In other words, the distance between the second part 62 and the shutter 1 1 at the inner recess 66 is greater than a radius of action of the magnet within which the latter has a force of movement sufficient to attract the shutter 1 1.

On the other hand, during the final position, the second part 62 of the holding means 60 and the first part 61 of the holding means 60 are aligned with the field of magnetic attraction in such a way as to activate the means 60 for holding in position. In effect, the two parts attract each other magnetically.

In other words, the first part 61 of the holding means 60 and/or the second part 62 of the holding means 60 is positioned inside the field of magnetic attraction.

The second part 62 is not aligned with the recess 66 and aligned with the remaining part the shutter 1 1 not affected by the recess 66 in such a way that the magnetic field made by the second part 62 influences the shutter 1 1. In other words, the distance between the second part 62 and the shutter 1 1 is less than a radius of action of the magnet within which the latter has a force of movement sufficient to attract the shutter 1 1.

As already mentioned, the rotor 64 is configured for moving from the initial position to the final position under the action of the comburent in transit along the first inlet 41 . The system 100 comprises a return spring 72 operatively connected between the fixed portion and the rotor 64 and configured to return the latter from the final position to the initial position. Preferably, in the accompanying drawings it is possible to see that the second part 62 comprises two magnets aligned with two respective recesses 66 of the shutter.

Moreover, the system 100 comprises an additional inlet 67 for the comburent positioned in fluid communication with the ventilation means 40 and a separator baffle 68 movable along an axis of movement between a rest position in which it closes the additional inlet 67 for the comburent and an operating position in which it opens the additional inlet 67 for the comburent.

More specifically, the separator baffle 68 is directly exposed to the flow of comburent passing along the first inlet 41 in such a way as to move from the rest position to the operating position according to the increase or reduction in the flow rate of the comburent acting on the separator baffle 68. In other words, the separator baffle 68 is movable from the rest position to the operating position when the flow rate of the comburent exceeds a predetermined flow rate value.

Alternatively, since the unit 63 for detecting the comburent is configured to measure the flow rate of the comburent along the first inlet 41 , the separator baffle 68 is connected the detection unit 63 and is movable from the rest position to the operating position with the increase in the flow rate of the comburent measured by the detection unit 63.

Moreover, the system 100 comprises elastic return means 69 interposed between the separator baffle 68 and a fixed portion of the integrated system 100 for the return of the separator baffle 68 from the operating position to the rest position. Preferably, the fixed portion of the integrated system 100 faces a side of the separator baffle 68 opposite to the holding means 60.

The elastic return means 69 also define a force of partial contrast against the force exerted by the comburent on the separator baffle 68.

Preferably, the elastic return means 69 are of the variable resistance type in such a way as to increase the degree of resistance during the movement of the separator baffle 68 from the rest position to the operating position.

Advantageously, the separator baffle 68 makes it possible to increase the supply of comburent towards the ventilation means 40 as a function of the flow rate of the comburent.

As shown in the accompanying drawings, the separator baffle 68 occupies the entire transversal cross section of the first inlet 41 . Consequently, the separator baffle 68 has a passage hole 70 for the transit of the comburent towards the ventilation means 40. Preferably, the rotor 64 comprises a central body 71 positioned at the axis of rotation partly inserted in the passage hole 70 during the rest position of the separator baffle 68. In that way, the passage hole 70 is restricted by the presence of the central body 71 of the rotor 64. In other words, the central body 71 of the rotor 64 positioned inside the passage hole 70 defines a neck for the comburent in transit.

If the first inlet 41 and the second inlet 54 are joined in the single opening, the passage hole 70 defines a passage both for the transit of the fuel and the comburent. In that case, the separator baffle 68 is positioned at the single inlet opening.

In addition, the additional inlet 67 merges into the single inlet opening made on the ventilation means 40.

Preferably, as shown in the accompanying drawings, the axis of movement 12, the axis of rotation and the axis of movement are aligned along a common direction.

With regards to the ventilation means 40, these comprise an axial extraction fan at the first inlet 41 and the second inlet 54 and a radial extraction fan at the outlet.

In addition, it should be noted that in the accompanying drawings the valve 1 comprises a further stage located downstream of the opening 6. In that sense, the valve 1 has a further opening 7 located downstream of the opening 6, according to the main path, and extending along a respective axis of extension 52 positioned transversally to the axis of extension 12 the opening 6. Preferably, the axis of extension 52 of the further opening 7 is positioned at right angles to the axis of extension 12 of the opening 6. In that way, once the gas has passed through the opening 6 it must turn through approximately a right angle to leave from the further opening 7. More specifically, the further stage comprises an intermediate chamber 5 interposed between the two stages and forming a communication space. More specifically, the intermediate chamber 5 is positioned between the opening 6 and the further opening 7.

It should also be noted that the intermediate chamber 5 extends away from the opening 6 to the top wall 10 which delimits the intermediate chamber 5.

In addition, the valve 1 comprises a further shutter 13 operatively associated with the further opening 7 and movable between a closed position and an open position of the further opening 7 along the direction of movement 12 transversal to the main path. Preferably, the further shutter 13 is positioned above the opening 6 according to the axis of extension 53. On the contrary, the shutter 1 1 is positioned below the opening 6 according to the axis of extension 53.

More specifically, the shutter 1 1 and the further shutter 13 are mutually superposed along the direction of movement 12. In other words, the shutter 1 1 moves in the end portion 8 of the inlet duct 2, whilst the further shutter 13 moves inside the intermediate chamber 5. In any event, the further shutter 13 is movable along the direction of movement 12. In other words, the further shutter 13 moves along the same direction of movement 12 of the shutter 1 1 . In yet other words, the shutter 1 1 and the further shutter 13 move coaxially even if independently with regard to the direction of movement (as will be explained in more detail below).

As already mentioned, the rod 16 is movable along the direction of movement 12 according to a second direction 21 opposite to the first direction to move the further shutter 13 from the closed position to the open position in such a way that the movement of a shutter 1 1 is independent of the movement of the other shutter 13. In other words, the movement of the shutter 1 1 is independent of the movement of the further shutter 13. In effect, this independence of the movements is given by the fact that for moving a shutter 1 1 it is necessary for the rod 16 to move in a direction opposite to the movement for the further shutter 13. In that way, it should also be noted that the time the shutter 1 1 remains in the closed position is independent of the time the further shutter 13 remains in the closed position.

More in detail, the rod 16 is inserted through a through hole 22 present on the further shutter 13. In other words, the rod 16 passes through the further shutter 13. It should be noted that the through hole 22 of the further shutter 13 has a greater width than the respective width of the rod 16 (measured perpendicularly to the direction of movement 12) in such a way as to leave a gap 33 between the further shutter 13 and the rod 16 for the passage of the fluid when the shutter 1 1 is open and the further shutter 13 is closed. Moreover, the gap 33 allows the sliding of the rod 16 relative to the further shutter 13 in such a way that the rod 16 can be moved irrespective of the movement of the further shutter 13.

Moreover, the movement unit 15 comprises pulling means 23 fixed to the operating portion 17 of the rod 16 for pulling the further shutter 13 from the closed position to the open position. More in detail, the pulling means 23 comprise a stop fixed to the operating portion 17 of the rod 16 and projecting laterally to it. More specifically, the stop protrudes laterally for a length greater than the space between the further shutter 13 and the rod 16 according to a direction perpendicular to the direction of movement 12 in such a way as to pull the further shutter 13 during the movement of the rod 16 according to the second direction 21 . Preferably, the stop is a washer fixed to the rod 16 at a suitable seat. Alternatively, the stop may be defined by a suitable protrusion formed on the profile of the rod 16.

Moreover, the valve 1 comprises first sealing means 24 and second sealing means 25 positioned between the further shutter 13 and the further opening 7. The second sealing means 25 are spaced from the first sealing means 24 along a direction away from the first sealing means 24. It should be noted that the intermediate chamber 5 has a widening at the further opening 7. In other words, at the height of the further opening 7, according to the direction of movement 12, there is the widening.

More specifically, the widening of the intermediate chamber 5 defines a space for detachment of the further shutter 13 placed in fluid communication with the further opening 7.

It should be noted that the intermediate chamber 5 has a first passage 27 defined between the further opening 7 and the detachment space and a second passage 28 defined between the top wall 10 and the detachment space. Consequently, the first sealing means 24 operate on the first passage 27, while the second sealing means 25 operate on the second passage 28 in such a way that the gas does not pass (during the closed position of the further shutter 13) in the detachment space.

Moreover, the second sealing means 25 comprise a first part 29 connected to the intermediate chamber 5 and a second part 30 connected to the further shutter 13. The first and second parts 30 of the second sealing means 25 have an annular extension around the further shutter 13.

It should be noted that the second passage 28 is defined between the intermediate chamber 5 and the further shutter 13 at the second sealing means 25.

In the preferred embodiment illustrated in the accompanying drawings, the first 29 and the second part 30 of the second sealing means 25 comprise a single body and are connected together by a flexible portion with a U shape. Moreover, in this preferred embodiment, the first sealing means 24 and the second part 30 of the second sealing means 25 comprise separate bodies.

Moreover, the intermediate chamber 5 comprises a transient space 32 extending away from the first sealing means 24 and from the shutter 1 1 . The transient space 32 is in fluid communication, during the closed position of the further shutter 13, with the rest of the intermediate chamber 5 through the gap 33. More specifically, the transient space 32 extends from the top wall 10 to the second passage 28.

In that way, after the shutter 1 1 has been opened, the gas flows through the gap 33 in such a way as not to exert pressure on the further shutter 13 along the second direction 21 . In other words, the thrust of the gas disperses through the gap 33 and by the passage of the gas in the transient space 32.

Moreover, the valve 1 comprises second elastic means 38 positioned between the further shutter 13 and the top wall 10 of the intermediate chamber 5. The second elastic means 38 are extended during the closed position of the further shutter 13 and compressed during the open position of the further shutter 13 in such a way as to facilitate the return of the further shutter 13 from the open position to the closed position. Moreover, the second elastic means 38 are designed to keep the further shutter 13 in the closed position. It should be noted that the second elastic means 38 extend inside the intermediate chamber 5 and, in detail, in an inner cavity 39 of the further shutter 13. In effect, the further shutter 13 substantially has a U shape wherein the opening of this U shape is directed towards the top wall 10. The shape of the further shutter 13 forms the inner cavity 39 in which the second elastic means 38 are at least partly positioned. In other words, the second elastic means 38 extend along the direction of movement 12. More in detail, the second elastic means 38 are positioned around the rod 16. Preferably, the second elastic means 38 comprise a helical spring inside of which the rod 16 passes. Thus, the spring also extends inside the inner cavity 39 of the further shutter 13.

Further, it should be noted that both the embodiments of the valve 1 comprise third elastic means 49 positioned between a wide portion of the rod 16 positioned in the inner cavity 39 and a contact surface of the further shutter 13 delimiting the inner cavity 39 along the direction of movement 12 according to the first direction 19. The wide portion of the rod 16 defines a step for retaining the third elastic means 49 in such a way as to lock them in position. Advantageously, the third elastic means 49 allow the pushing means 23 to be kept in contact with the further shutter 13 during the closed position.

As regards the operation of this invention it may be derived directly from the description above.

More specifically, the unit 63 for detecting the transit of the comburent activates the means 60 for holding in position to keep the shutter 1 in the open position when there is passage of comburent (Figure 5).

In the particular embodiment illustrated in the accompanying drawings wherein the detection unit 63 comprises a rotor 64, the transit of the comburent move the rotor 64 so that, thanks to the movement of the latter, the system 100 understands that it is possible keep open the shutter 1 1 for supplying fuel.

In that way, in the absence of transit of comburent towards the ventilation means 40, the rotor 64 stops (preferably returns to its initial position) deactivating the means 60 for holding in position. In that way, the shutter 1 1 may not remain locked in the open position and returns to the closed position stopping the flow of fuel and thus putting the system 100 in a safe condition (Figure 4).

Moreover, during the operation of the system 100 with transit of comburent and with the shutter 1 1 in the open position, it is possible open a further air passage by moving the separator baffle 68 which is sensitive to the flow rate of the comburent (Figure 7). In practice, the separator baffle68, under the action of the pressure of the comburent, moves to open the further air passage. In that way, when the comburent flow rate increases beyond a certain limit, the system 100 allows the supply of comburent to be increased.

Lastly, the opening of the further valve stage (Figure 6) allows the specified safety to be guaranteed with regard to valves which manage combustible fluids.

More specifically, the opening of the valve 1 comprises an opening of the first stage and an opening of the further stage.

In order to open the first stage it is necessary to move the rod 16 along the first direction 19 using a suitable command to the electromagnetic circuit 46 in such a way as to move the shutter 1 1 from the closed position to the open position. During this movement (or before) the magnetic attraction means 36 are activated (thanks to the movement of the rotor 64) in such a way as to complete the movement from the shutter 1 1 from the closed position to the open position. More specifically, the magnetic attraction means 36 attract the shutter 1 1 towards the closing wall 9 in such a way as to definitively open the first stage. In other words, the movement of the shutter 1 1 occurs at two successive points in time: during a first instant, the rod 16 moves the shutter 1 1 close to the closing wall 9; during a second instant, the magnetic attraction means 36 complete the movement of the shutter 1 1 towards the closing wall 9.

After the opening of the shutter 1 1 , the magnetic attraction means 36 are kept active in such a way that the shutter 11 remains in the open position. During the opening movement of the shutter 1 1 , the first elastic means 34 are compressed while the second elastic means 38 keep the shutter 13 in the closed position.

Once the shutter 1 1 is open, the gas enters through the opening 6 into the intermediate chamber 5 and penetrates into the gap 33 arriving at the transient space 32. However, until the further shutter 13 is opened, the gas is locked inside the intermediate chamber 5 (and in the transient space 32) thanks to the presence of the first sealing means 24 and second sealing means 25.

Then, the rod 6 is moved from the first operating condition to the second operating condition, in the second direction 21. In this way, the pulling means 23 associated with the operating portion 17 of the rod 16 move the further shutter 13 from the closed position to the open position generating a passage for the gas from the gap to the outlet duct 3. During this movement, the second elastic means 38 are compressed. After the opening of the further shutter 13, the gas can pass through the valve 1 . The present invention achieves the set aims.

More specifically, this system makes it possible to increase the level of safety in situations in which there is not a sufficient comburent flow rate since the means for holding in position at least one of the valve stages is deactivated in the absence of passage of the comburent. Consequently, if the ventilation means are blocked or the entrance for the comburent is obstructed, the valve 1 closes automatically.

In addition, when the shutter is in the open position, the means for holding in position keep it in that position only with the transit of comburent towards the ventilation means.

Moreover, when the comburent flow rate increases beyond a certain limit, the system allows the supply of comburent to be increased by moving a separator baffle which allows a further opening passage to opened.

It should also be noted that this invention is relatively easy to implement and that the cost of implementing the invention is relatively low.

Claims

1. An integrated system (100) for regulating and mixing comburent and fuel for a burner, comprising:

a valve (1 ) for the fuel comprising an inlet passage (8) and an outlet 5 passage (80) for the fuel;

ventilation means (40) comprising a first inlet (41 ) for the comburent, a second inlet (54) for the fuel and an outlet connectable to the burner; the second inlet (54) for the fuel being connected to the outlet passage of the valve (1 ) for receiving the fuel passing through the valve i o (1 );

the valve (1 ) comprising a valve stage comprising a shutter (1 1 ) interposed between the inlet passage (8) and the outlet passage (80) and movable along a movement axis (12), between an open position, to allow the passage of the fuel, and a closed position to block the passage of the 15 fuel;

the valve (1 ) also comprises a unit (15) for moving the shutter (1 1 ) operatively associated with the shutter (1 1 ) for moving it from the closed position to the open position;

characterised in that the valve stage comprises means (60) for

20 holding in position operatively active between a fixed portion (9) of the valve (1 ) and the shutter (1 1 ) and which can be configured between an activation condition during which they keep the shutter (1 1 ) in an open position, and a deactivation position; during the activation condition, the means (60) for holding in position being configured for acting on the

25 shutter (1 1 ) when the latter is in an intermediate position between the open position and the closed position; the unit (15) for moving the shutter (1 1 ) being configured for moving the shutter (1 1 ) from the open position to the intermediate position;

and characterised in that it comprises a unit (63) for detecting

30 comburent along the first inlet (41 ) configured for detecting the presence of comburent in transit along the first inlet (41 ); the system (100) comprising means for activating the means (60) for holding in position operatively connected to the unit (63) for detecting the comburent and configured for activating the means (60) for holding in position when the unit (63) for detecting comburent detects the presence of comburent in transit along the first inlet (41 ).

2. The system (100) according to claim 1 , characterised in that the means (60) for holding in position are of the magnetic type and define a field of magnetic attraction extending from the open position to the intermediate position of the shutter (1 1 ).

3. The system (100) according to claim 2, characterised in that a first part (61 ) of the means (60) for holding in position is positioned at the shutter (1 1 ) whilst a second part (62) of the means (60) for holding in position is positioned at a closing wall (9) of the valve (1 ) spaced from the shutter (1 1 ); the shutter (1 1 ) being movable from the intermediate position to the open position along a direction of approach to the closing wall (9).

4. The system (100) according to claim 2 or 3, characterised in that the first part (61 ) of the means (60) for holding in position comprises a magnet (37); the second part (62) of the means (60) for holding in position comprising a magnet and/or ferromagnetic material associated with the shutter (1 1 ).

5. The system (100) according to any one of the preceding claims, characterised in that the unit (63) for detecting comburent comprises a rotor (64) exposed to the comburent in transit along the first inlet (41 ) in such a way as to be moved by the passage of the comburent to detect the passage of the comburent.

6. The system (100) according to claim 5, characterised in that it comprises a communication compartment (65) shared between the first inlet (41 ), the second inlet (54) and the outlet passage.

7. The system (100) according to claim 6, characterised in that the detection unit (63) is positioned in the communication compartment (65).

8. The system (100) according to any one of claims 5 to 7 when dependent on claim 2, characterised in that a first part (61 ) of the means (60) for holding in position is positioned on the shutter (1 1 ) whilst a second part (62) of the means (60) for holding in position is incorporated in the rotor (64); the first part (61 ) and/or the second part (62) defining the field of magnetic attraction.

9. The system (100) according to claim 8, characterised in that the second part (62) of the means (60) for holding in position is positioned at a portion of the rotor (64) and the first part (61 ) of the means (60) for holding in position is positioned at a portion of the shutter (1 1 ); the rotor (64) being rotatable about an axis of rotation passing through the movement axis (12) from an initial position to a final position along a predetermined angular curve; during the initial position, the second part (62) of the holding means (60) or the first part (61 ) of the holding means (60) being positioned outside at least part of the field of magnetic attraction in such a way as to deactivate the means (60) for holding in position; during the final position, the second part (62) of the holding means (60) and the first part (61 ) of the holding means (60) being positioned inside at least part of the field of magnetic attraction in such a way as to activate the means (60) for holding in position.

10. The system (100) according to claim 9, characterised in that the rotor (64) is configured for moving from the initial position to the final position under the action of the comburent in transit along the first inlet (41 ); the system (100) comprising a return spring (72) operatively connected to the rotor (64) and configured to return the latter from the final position to the initial position.

11. The system (100) according to any one of the preceding claims, characterised in that the first inlet (41 ) and the second inlet (54) merge into a single inlet opening made on the ventilation means (40).

12. The system (100) according to any one of the preceding claims, characterised in that it comprises an additional inlet (67) for the comburent positioned in fluid communication with the ventilation means (40) and a separator baffle (68) movable along an axis of shifting between a rest position in which it closes the additional inlet (67) for the comburent and an operating position in which it opens the additional inlet (67) for the comburent.

13. The system (100) according to claim 12, characterised in that the separator baffle (68) is directly exposed to the flow of comburent passing along the first inlet (41 ) in such a way as to move from the rest position to the operating position according to the increase or reduction in the flow rate of the comburent acting on the separator baffle (68).

14. The system (100) according to claim 13, characterised in that it comprises elastic return means (69) associated with the separator baffle (68) for the return of the latter from the operating position to the rest position; the elastic return means (69) defining a force of partial contrast against the force exerted by the comburent on the separator baffle (68).

15. The system (100) according to any one of claims 12 to 14, characterised in that the separator baffle (68) occupies the entire transversal cross-section of the first inlet (41 ); the separator baffle (68) having a passage hole (70) for the transit of the comburent towards the ventilation means (40).

16. The system (100) according to any one of claims 12 to 15, characterised in that the movement axis (12) , the axis of rotation and the axis of shifting are aligned along a common direction.

17. The system (100) according to any one of claims 12 to 16, characterised in that the additional inlet (67) merges into the single inlet opening made on the ventilation means (40); the separator baffle (68) being positioned at the single inlet opening.

18. The system (100) according to any one of the preceding claims, characterised in that the ventilation means (40) comprise an axial extraction fan at the first inlet (41 ) and the second inlet (54) and a radial extraction fan at the outlet.

19. The system (100) according to any one of the preceding claims, characterised in that the movement unit (15) is movable from an initial position, wherein it is spaced from the shutter (1 1 ) along the movement axis (12), towards an interception position of the shutter (1 1 ) wherein it is in contact with the shutter (1 1 ), to an intermediate position wherein the shutter (1 1 ) is in the intermediate position.

20. The system (100) according to claim 19, characterised in that the movement unit (15) comprises a rod (16) extending between a respective operating portion (17) which can engage the shutter (1 1 ) for moving it and a respective drive portion (18) opposite to the operating portion (17).

21. The system (100) according to claim 20, characterised in that it comprises means (42) for driving the rod (16) associated with the drive portion (18) of the rod (16); the drive means (42) comprising an electromagnetic element (44) to move the rod (16) along a first direction (19) or along a second direction (21 ) for opening or closing the shutter (1 1 ).

22. The system (100) according to claim 21 , characterised in that the electromagnetic element (44) comprises a magnet (45) fixed in position relative to the rod (16) and an electromagnetic circuit (46) connected to the drive portion (18) of the rod (16); the electromagnetic circuit (46) being operatively associated with the magnet (45) and movable towards or away from it.

23. The system (100) according to any one of the preceding claims, characterised in that the valve (1 ) comprises a further valve stage positioned between the valve stage and the outlet passage (80); the further valve stage comprises a further shutter (13) movable independently of the shutter (1 1 ) of the valve stage.