"ADJUSTING DEVICE FOR HEAT GENERATORS".

TECHNICAL FIELD OF THE INVENTION

The present invention concerns an adjusting device for heat generators.

More in particular, the present invention concerns an adjusting device for the air in inlet into solid fuel heat generators, such as wooden stoves and the like.

STATE OF THE ART

Some types of solid fuel heat generators for heating civil buildings, like for example air-tight wooden stoves for rooms of a house and the like, comprise adjustment systems for adjusting the flow rate of comburant air - also called primary air - entering the generator: such systems have been devised to allow the user to vary the characteristics of the combustion of the generator.

The most simple systems for adjusting the primary air flow rate comprise a manual shutter, that is for example slidingly associated with the base of the generator, which makes it possible to vary the section of the inlet duct of the primary air itself as desired.

Other types of more advanced generators are provided with a system for adjusting the flow rate of the primary air comprising an automatic rotating shutter, which is moved by an actuator, which is suitable for eliminating the need of intervention by the user. Moreover, the automatic opening shutter can be slaved to a control unit that, by detecting the temperature of the fumes inside the generator, makes it possible to intervene in a more precise manner on the parameters of the combustion and to reduce discharge emissions.

It has however been found in practice that this last type of adjustment system makes it possible to precisely adjust the flow rate of the primary air entering the furnace, but it does not make it possible to intervene in any way on the actual distribution of air itself inside the furnace.

More in detail, normal automatic valve systems do not make it possible to achieve an effective control of the mass proportions between the aforementioned primary air, which flows towards the grill of the brazier, and the so-called secondary air, i.e., the air that flows along the window of the generator for cleaning it.

Since in modern heat generators preference is given to the flow of secondary air over that of primary air in order to keep down emission of carbon monoxide, the fact that it is impossible to adjust the proportions between primary and secondary air mass that flow inside the generator as desired is a major drawback.

PURPOSES OF THE INVENTION

The technical task of the present invention is that of improving the state of the art.

In such a technical task, one purpose of the present invention is to devise an adjusting device for heat generators that makes it possible to efficiently control both the quantity of primary air mass and secondary air mass that are introduced inside the generator itself, so as to optimise combustion efficiency.

Again another purpose of the present invention is to provide an adjusting device for heat generators that is simple and cost-effective to make.

A further purpose of the present invention is to make an adjusting device that can be easily installed in any solid fuel heat generator of the type of wooden stoves and the like, even already operational ones.

This task and these purposes are achieved with the adjusting device for heat generators according to attached claim 1.

The adjusting device according to the invention comprises at least one box-shaped body, which is provided with at least one inlet opening for the comburant air and of at least one outlet opening for the comburant air, and at least one rotatable gate valve, housed inside said box-shaped body and interposed between the inlet opening and the outlet opening.

The gate valve can rotate being suitable for varying the passage section of the comburant air through the box-shaped body.

The adjusting device moreover comprises at least one dividing element, which is interposed between the rotatable gate valve and the outlet opening, defining a first passageway and a second passageway for the comburant air that are isolated from one another; the first passageway and the second passageway are suitable for being placed in communication with respective distinct paths of the comburant air foreseen in the heat generator. The rotatable gate valve, according to one important aspect of the invention, comprises a support shaft to which a laminar element is associated; such a laminar element comprises a first portion and a second portion that are coplanar with one another and are respectively suitable for selectively obstructing said first passageway and said second passageway by rotation of the aforementioned support shaft.

The dividing element foreseen in the adjusting device makes it possible to separate, immediately downstream of the gate valve, the passageway of the primary comburant air from the passageway of the secondary comburant air, so that the respective flow rates can be controlled separately from one another, even independently from one another.

Claim 13 moreover refers to a heat generator comprising the adjusting device according to claim 1.

The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention shall become clearer by any man skilled in the art from the following description and from the attached drawing tables, given as a non- limiting example, in which: figure 1 is a front view of a heat generator comprising the device according to the invention;

figure 2 is a rear view of the heat generator of figure 1 ;

figure 3 is a section view of the heat generator sectioned along the plane III-III of figure 2;

figure 4 is a top view of the heat generator;

figure 5 is a view of the heat generator from below;

figure 6 is a section view of the heat generator sectioned along the plane VI- VI of figure 1 ;

figure 7 is a perspective view of the generator with some parts removed for the sake of greater clarity;

figure 8 is a perspective view of the device according to the invention;

figure 9 is a front view of the device; figure 10 is a rear view of the device;

figure 11 is a section view of the device sectioned along the plane XI-XI of figure 9;

figure 12 is a section view of the device sectioned along the plane XII-XII of figure 9;

figure 13 is an exploded axonometric view of the device;

figure 14 is another perspective view of the device with some parts removed for the sake of clarity;

figure 15 is a detailed section of the device, in an operating step of the heat generator;

figure 16 is a section view of the device sectioned along the plane XVI-XVI of figure 15;

figure 17 is an exploded axonometric view of parts of the gate valve of the device;

figure 18 is a top view of parts of the gate valve;

figure 19 is a side view of parts of the gate valve.

EMBODIMENTS OF THE INVENTION

With reference to the attached figure 3, reference numeral 1 wholly indicates an adjusting device for heat generators according to the present invention.

In particular, in figures 1-8 and 14 the adjusting device 1 according to the invention is illustrated installed inside a respective heat generator, wholly indicated with reference numeral 2.

The heat generator 2 is, in particular, of the solid fuel type.

More in detail, in the embodiment described and illustrated the generator 2, only as a non-limiting example, consists of a wood stove with an airtight chamber.

In other embodiments of the invention, the heat generator in which the adjusting device

1 is installed could also be of another type, without limiting the purposes of the present invention.

The generator 2 comprises, in detail, a base 3.

The base 3 is parallelepiped shaped, but it could of course have another shape, without any limitation.

Inside the base 3 a furnace 4 or combustion chamber is housed. In the front part of the base 3 a closing hatch 5 for the furnace 4 is foreseen; the closing hatch 5 is provided with a window 6, which makes it possible to see the flame inside the furnace 4.

Inside the furnace 4 a brazier 7 is housed, with a respective grill 8.

As illustrated in particular in figures 4, 5, the base 3 comprises lower openings 9 and upper openings 10 that define, inside the generator 2, a path for convective air to pass, indicated with A in figure 3.

The convective air A flows from below through natural convection or it is sucked, for example, through fan means, it reaches the furnace 4 and heats, to then be directly discharged into the environment or into suitable conveying ducts towards the desired room.

In the lower part of the base 3 an inlet duct 11 for the comburant air is foreseen, communicating with the outer environment.

Inside the generator 2 paths are defined for the primary comburant air and the secondary comburant air, and possibly also tertiary comburant air, or post-combustion air.

In particular, again with reference to figure 3, the path of the primary comburant air B substantially develops from the inlet duct 1 1 to the area of the furnace 4 below the grill 8 of the brazier 7.

The path of the secondary comburant air C, on the other hand, substantially develops from the inlet duct 11 to the area immediately above the closing hatch 5, so as to reach the inner surface 6a of the window 6.

The path of the tertiary comburant air D or post-combustion air, finally, substantially develops from the inlet duct 11 to the rear area of the furnace 4.

The adjusting device 1 according to the invention is illustrated, in greater detail, in figures 9-13 and 15-19.

The adjusting device 1 comprises a box-shaped body 12.

The box-shaped body 12 comprises an inlet opening 13 for the comburant air, and an outlet opening 14 for the comburant air.

In the represented embodiment, the inlet opening 13 of the box-shaped body 12 is directly placed in contact with the inlet duct 11, which has a flanged end 15 that can be connected, for example, to the base 3 of the heat generator 2, or to other parts thereof. The outlet opening 14 comprises a flanged portion 16 for connecting to parts of the generator 2, as shall be described in greater detail hereafter.

The box-shaped body 12 moreover comprises a rotatable gate valve 17.

More in detail, the box-shaped body 12 comprises a single rotatable gate valve 17. The rotatable gate valve 17 is inserted inside the box-shaped body 12, in the way that shall be described in greater detail hereafter.

The rotatable gate valve 17 is, in more detail, interposed between the inlet opening 13 and the outlet opening 14.

The rotatable gate valve 17 is suitable for varying, according to predetermined modalities, the passage section of the comburant air through the box-shaped body 12. According to one aspect of the present invention, the adjusting device 1 comprises a dividing element 18.

The dividing element 18 is interposed between the rotatable gate valve 17 and the outlet opening 14 of the comburant air.

In other words, the dividing element 18 is placed downstream of the rotatable gate valve 17 with reference to the flow of air from the inlet opening 13 to the outlet opening 14. The dividing element 18 defines, inside the box-shaped body 12, a first passageway 19 and a second passageway 20 for the comburant air, which are isolated from one another. In the section that affects the box-shaped body 12, the first passageway 19 and the second passageway 20 develop according to respective directions that are parallel or substantially parallel to one another.

In more detail, as shall be explained more clearly hereafter, the first passageway 19 and the second passageway 20 are suitable for being placed in communication with respective distinct paths for the comburant air B', C foreseen in the generator 2.

The box-shaped body 12 is arranged substantially vertical inside the generator 2, and is joined to the inlet duct 11 of the comburant air; more in particular, the box-shaped body 12 is joined to the inlet duct 11 so as to define a right-angle elbow.

The shape of the cross-section of the box-shaped body 12 can be any, in relation to the specific application requirements.

The box-shaped body 12 comprises a front wall 21, a rear wall 22 and two side walls 23, 24.

The front wall 21 of the box-shaped body 12 has an inspection opening 25 that is closed by a lid 26, which keeps a sealing gasket 27 in place. The rotatable gate valve 17 comprises a support shaft 28.

The support shaft 28 has the terminal ends 29 that are rotatably supported in the side walls 23,24 of the box-shaped body 12.

In particular, as visible for example in figures 1 1 and 15, the support shaft 28 has the terminal ends 29 that are rotatably supported at the centre line of the side walls 23, 24, so that the support shaft 28 is positioned equidistant from the front wall 21 and from the rear wall 22.

The valve 17 moreover comprises a laminar element 30 that is associated with the support shaft 28.

The laminar element 30 is illustrated in detail in figures 17-19.

In particular, the support shaft 28 comprises a flat surface 31 to which the laminar element 30 is fixed, for example with central screws 32.

The laminar element 30 is fixed to the support shaft 28 so that its opposite edges are positioned on opposite sides with respect to the axis of the support shaft 28.

More in particular - by observing the valve 17 in section - the laminar element 30 is fixed to the support shaft 28 so as to be able to be moved, when needed, to one side or the other obtaining, with respect to the axis of the support shaft 28 itself, two segments the lengths of which can be changed as desired.

This, as shall become clearer hereafter, makes it possible to selectively vary, at the discretion of the user, the adjustment modalities of the first passageway 19 and of the second passageway 20.

According to one aspect of the invention, the laminar element 30 comprises a first portion 30a and a second portion 30b.

The first portion 30a and the second portion 30b are coplanar with one another.

The first portion 30a and the second portion 30b are respectively suitable for selectively obstructing the first passageway 19 and the second passageway 30 by rotation of the support shaft 28.

In figure 1 1 the rotatable gate valve 17 is illustrated in the position in which the first passageway 19 and the second passageway 20 are completely obstructed, respectively by the first portion 30a and by the second portion 30b of the laminar element 30.

In this position, the laminar element 30 has its opposite edges that respectively abut against the front wall 21 and against the rear wall 22. In figures 15 and 16, on the other hand, the valve 17 is illustrated in a certain operative position in which the first passageway 19 and the second passageway 20 are both open. In particular, as can be understood, the rotation of the valve 17 makes it possible to simultaneously and progressively vary both the section of the first passageway 19 and the second passageway 20.

In other words, the rotation of the single valve 17 makes it possible to act simultaneously on the adjustment of the first passageway 19 and on the second passageway 20, by using a single valve body made up of the laminar element 30, with the first portion 30a and the second portion 30b that rotate as a unit with one another. Therefore, in relation to the rotation of the support shaft 28, and also to the fixing position of the laminar element 30 with respect to the support shaft 28 itself (for example symmetric or asymmetric with respect to the support shaft 28), it is possible to obtain various adjustment conditions in relation to the specific application requirements. In other words, first and second portions 30a, 30b can be obtained with different dimensions by using a same laminar element 30.

According to one aspect of the present invention, the laminar element 30 comprises an end appendage 33 that is elastically yieldable.

The elastically yieldable end appendage 33 is foreseen along one of the opposite edges of the laminar element 30.

The end appendage 33 is, more in particular, foreseen along the end edge of the first portion 30a of the laminar element 30.

As shall be made clearer hereafter, the end appendage 33 is suitable for sealingly abutting on at least one of the walls 21, 22, 23, 24 of the box-shaped body 12, for at least one part of the rotation of the support shaft 28.

In more detail, the end appendage 33 is suitable for sealingly abutting against the rear wall 22 of the box-shaped body 12, with the technical advantages that shall be illustrated in greater detail in the rest of the description.

According to another aspect of the present invention, the laminar element 30 is folded back on itself like a wallet.

The laminar element thus 30 defines two matching edges 34, which lock the elastically yieldable end appendage 33 between one another.

In more detail, the end appendage 33 comprises a tubular portion 35 and a laminar portion 36.

The laminar portion 36 is connected to the tubular portion 35 along a generatrix of its outer surface, and it is suitable for being locked between the aforementioned matching edges 34.

In the embodiment shown, the laminar element 30 is locked on the end appendage 33 through screws 37 inserted in respective threaded holes 38 foreseen in the laminar element 30 itself.

In other embodiments of the invention, the locking of the laminar element 30 on the end appendage 33 could be carried out with equivalent locking members.

As previously mentioned, the support shaft 28 is fixed to the laminar element 30 substantially along the longitudinal centre line of the latter.

This solution makes it possible, with the laminar element 30 in the closing configuration - in particular, in the figures, arranged horizontally - to have both passageways 19, 20 that are obstructed.

In other embodiments of the invention that are not represented in the figures, the support shaft 28 could be fixed to the laminar element 30 along an axis that is parallel to the aforementioned centre line axis, so as to obtain a non-symmetrical arrangement of the laminar element 30 itself with respect to the support shaft 28.

This other solution makes it possible, as previously mentioned, to differentiate the sections of the first passageway 19 and of the second passageway 20 as desired.

For example, it is possible to make a solution in which one of the two passageways 19, 20 is completely obstructed, whereas the other one is always open, even if only with a minimal opening.

The laminar element 30, in the embodiment represented in the figures, comprises openings 39 that are suitable for the passage of the comburant air.

Also this solution makes it possible to differentiate the sections of the first 19 and/or of the second 20 passageway as desired.

More in particular, thanks to this solution it is possible to increase by a certain amount the section of the first passageway 19 or of the second passageway 20.

The adjusting device 1 according to the invention moreover comprises an actuation motor 40 for actuating the rotatable gate valve 17.

The actuation motor 40 comprises an outlet axis that is rigidly connected to one of the terminal ends 29 of the support shaft 28.

As illustrated for example in figure 13, the actuation motor 40 is fixed with screws to the outer surface of the box-shaped body 12, preferably on a bracket 41 connected - for example through welding - to the aforementioned outer surface.

The actuation motor 40 is operatively connected to the control means for controlling the operation of the heat generator 2, which are not part of the present invention.

The dividing element 18 has a laminar shape.

The dividing element 18 comprises, more in particular, a first end edge 42 and an opposite second end edge 43, which are fixed to the side walls 23, 24 of the box-shaped body 12, respectively.

In particular, the first end edge 43 and the second end edge 44 are folded back at a right angle with respect to the surface of the dividing element 18, and are fixed to the side walls 23, 24 of the box-shaped body 12, for example through screws.

The dividing element 18 comprises a third end edge 44.

The third end edge 44 is, in particular, placed in contact with the support shaft 28 of the rotatable gate valve 17.

In such a way, it is possible to obtain an efficient isolation between the first passageway 19 and the second passageway 20.

Moreover, the dividing element 18 comprises a fourth end edge 45 that is folded back over itself, opposite to the third end edge 44.

As shall be made clear in the rest of the description, the fourth end edge 45 folded back over itself makes it possible to obtain the joint between the passageways 19, 20 and the paths B', C of the comburant air that are foreseen in the generator 2.

The operation of the adjusting device 1 according to the invention is intuitive.

By rotation the support shaft 28 of the valve 17 through the actuation motor 40, it is possible to simultaneously vary the section of the first passageway 19 and of the second passageway 20, so as to adjust as desired, and in a controlled manner, the flow rate of the primary comburant air B and of the secondary comburant air C.

According to an interesting aspect of the invention, the end appendage 33 of the laminar element 30, which as mentioned is elastically yieldable, is mounted so as to sealingly abut against the rear wall 22 of the box-shaped body 12 for a certain angular excursion in the rotation of the support shaft 28. In other words, the valve 17 is sized in such a way that the end appendage 33 is slightly deformed, or rather compressed, when the laminar element 30 is in the horizontal closed position, i.e., when the first portion 30a and the second portion 30b respectively obstruct the first passageway 19 and the second passageway 20.

The progressive rotation of the support shaft 28 makes it possible for there to be the gradual release of such a deformation, so that the end appendage 33 is in any case kept in sealing contact with the rear wall 22 of the box-shaped body 12 relating to the aforementioned angular excursion of the support shaft 28.

In the particular case in which the first passageway 19 is that of the primary comburant air B of the generator 2, thanks to this solution it is possible to progressively open the second passageway 20 - for the secondary comburant air C - and on the other hand, for a certain angular excursion of the support shaft 28, keep the first passageway 19 closed, so that no primary comburant air B enters inside the generator 2.

Of course, this makes it possible to give more weight to the feeding of the generator 2 with only secondary comburant air C or in any case with a greater flow rate of secondary comburant air C with respect to the primary comburant air B, with considerable advantages, for example, in terms of carbon monoxide emissions.

More in general, it is worth underlining that the adjusting device 1 according to the present invention can be used, inside a heat generator 2, for partializing and controlling the flow rates of comburant air that belong to any path inside the generator 2 itself, without any limitation to the purposes of the present invention.

One object of the present invention is also a heat generator 2 of the type previously described and comprising an adjusting device 1 with the illustrated characteristics.

In particular, in the generator 2 according to the invention, the path of the primary comburant air B is placed in communication with the first passageway 19 of the device 1 , whereas the path of the secondary comburant air C is placed in communication with the second passageway 20.

According to one aspect of the invention, the generator 2 comprises a box-shaped joining element 46, which is visible in particular in figures 8 and 14.

The joining element 46 is positioned at the top of the adjusting device 1.

In other embodiments, the joining element 46 could have a different arrangement inside the generator 2. The joining element 46 comprises, in more detail, an inlet entrance 47 for the comburant air communicating with the outlet opening 14 of the box-shaped body 12 of the device 1.

The inlet entrance 47 is foreseen in the lower wall of the joining element 46.

The joining element 46 moreover comprises first outlet ports 48 communicating with the first passageway 19 of the device 1 , and second outlet ports 49 communicating with the second passageway 20 of the device 1.

The first outlet ports 48 and the second outlet ports 49 are foreseen in the upper wall of the joining element 46.

The joining element 46 moreover comprises, inside it, a separation wall 50.

The separation wall 50 abuts against the dividing element 18.

In more detail, the separation wall 50 abuts against the fourth end edge 45 of the dividing element 18, and it is suitable for defining the initial sections of the path B' for the primary comburant air B and for the path C for the secondary comburant air C inside the generator 2.

The separation wall 50 divides the inlet entrance 47 in two portions, respectively corresponding to the first passageway 19 and to the second passageway 20 of the adjusting device 2.

The separation wall 50 makes it possible to obtain, in more detail, an effective isolated communication between the first passageway 19 of the device 1 and the first outlet ports 48, and between the second passageway 20 and the second outlet ports 49.

In other words, the joining element 46 makes it possible to effectively connect, and without the risk of unpleasant mixing of air, the first passageway 19 with the path B' of the primary comburant air B, and the second passageway 20 with the path C of the secondary comburant air C of the generator 2.

Indeed, relating to the generator 2, the first outlet ports 48 and the second outlet ports 49 of the joining element 46 communicate, isolated from one another, respectively with the path B' of the primary comburant air B and with the path C of the secondary comburant air C.

Of course, the joining element 46 can be shaped so as to obtain different connections between the adjusting device 1 and the various paths of the comburant air inside the generator 2. It has thus been seen how the invention achieves the proposed purposes.

The adjusting device according to the invention makes it possible to separate the flows of the primary and of the secondary comburant air immediately downstream of the gate valve 17, so as to control its flow rates to optimise the combustion of the heat generator. The particular gate valve 17 of the device according to the invention also makes it possible to vary, in an independent manner from one another, the passage sections of the primary and secondary comburant air, thus obtaining the desired effects on the efficiency of the combustion inside the generator.

The proposed solution is simple and cost-effective to make, and it can be also installed in existing heat generators.

According to an interesting aspect of the present invention, the results described above are obtained by using a single gate valve 17, which makes it possible - by singly controlling the rotation of the relative support shaft 28 - to simultaneously adjust the opening of the first passageway 19 and of the second passageway 20.

The present invention has been described according to preferred embodiments, but equivalent variants can be conceived without departing from the scope of protection offered from the following claims.