Marchi; Fabio De Zen

TECHNICAL FIELD OF THE INVENTION

The present invention concerns a device for treating combustion fumes and a heating apparatus equipped with such a device.

More in particular, the present invention concerns a device that can be applied to a heating apparatus, such as a heater, a fireplace or the like, which uses, as a product for combustion, a solid fuel like wood, pellets, wood chips, and the like.

STATE OF THE ART

Apparatuses for heating rooms, such as heaters, fireplaces and the like, supplied with solid fuels such as wood, pellets, wood chips, etcetera, are known and widespread .

Although these apparatuses make it possible to use renewable and non fossil-based energy sources, they are responsible for emitting pollutants and particulates into the atmosphere.

As it is known, such pollutants are especially made up of carbon oxides (in particular carbon monoxide, CO) , nitrogen oxides (NOx) , unburned hydrocarbons (HC) , etcetera; the particulate material generally consists of a group of solid particles having different chemical and granulometric composition (dusts like PM10, PM5 and PM2, 5) .

Such pollutants are considered responsible for various problems related to the pollution of the environment. Nowadays, most heating apparatuses are installed for civil or private use, and they are not provided with means for the abatement of the particulates or of the polluting substances present in combustion fumes. In such a way, the combustion fumes are directly discharged into the atmosphere without being treated. Some filtering systems are known, for example catalytic systems, electrostatically operating systems, etcetera, which can be installed, for example, in the flue. These are, however, systems which comprise a box-shaped support element with considerable dimensions. Such a box-shaped element is bulky and makes the passage of fumes worse in terms of fluid dynamics.

Such systems, therefore, are costly and require frequent . maintenance and replacement of the filtering parts, are considerably bulky and, in the case in which they operate electrostatically, they need to be supplied with electricity.

Therefore, such filtering systems rarely find application in heating apparatuses for civil use.

PURPOSES OF THE INVENTION

The technical task of the present invention is, therefore, that of improving the state of the art, by devising a device for treating combustion fumes which makes it possible to abate or substantially minimise the emission of polluting substances and of particulates present in the combustion fumes into the atmosphere .

In the field of such a technical task, one purpose of the present invention is to make a device for treating combustion fumes that is structurally and functionally simple .

A further purpose of the present invention is that of making a device for treating combustion fumes that is characterised by technical usage and maintenance features, and by installation bulk in the civil field, comparable to those of known types of apparatuses.

This task and these purposes are achieved with the device for treating combustion fumes according to the attached claim 1.

The technical task of the present invention is, therefore, that of improving the state of the art, by devising a device for treating combustion fumes that makes it possible to abate or substantially minimise the emission of polluting substances and particulates, present in combustion fumes, into the atmosphere.

A further purpose of the present invention is that of making a heating apparatus that is equipped with a device for treating combustion fumes that is characterised by technical usage features, and by installation bulk in the civil field, comparable to those of known types of apparatuses.

This task and these purposes are achieved with a heating apparatus that is equipped with a device for treating combustion fumes according to the attached claim 19.

According to one aspect of the present invention, the device for treating combustion fumes is positioned inside the passage tube of such fumes. When passing through said device, the fumes are progressively slowed down, and there is furthermore a purification of the harmful substances present in the fumes themselves.

After passing through such a device, therefore, there is a considerable decrease in the concentration of harmful substances that remains in the fumes that leave the heating apparatus and are directed towards the atmosphere .

Further advantageous characteristics are described in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

The characteristics of the invention shall become clearer to 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 perspective view of the device for treating combustion fumes according to the present invention;

figure 2 is a front schematic view of the device of figure 1;

figure 3 is a section view of the device of figures 1 and 2 taken according to the axis III of figure 2;

figure 4 is a schematic plan view of one version of the device according to the present invention;

figure 5 is a front schematic view of one embodiment of the device for treating combustion fumes according to the present invention;

figure 6 is a schematic plan view of one version of the device of figure 5;

figure 7 is a sectioned view of the device of figure 5 taken according to the axis VII of figure 5; figure 8 is a sectioned perspective view of a detail of the device according to figures 1-4;

figure 9 is a sectioned perspective view of a detail of the device according to figures 5-7;

figure 10 is a front view of an element of the device according to the present invention.

EMBODIMENTS OF THE INVENTION

With reference to the attached figures, a device for treating combustion fumes F of a heating apparatus (not shown) according to the present invention is wholly shown with reference numeral 1.

The heating apparatus according to the invention can consist, for example, of a heater, of a fireplace, or of any other similar apparatus that is supplied with biomass fuel such as wood, pellets or the like, without any limitation in terms of dimensions, usage, thermal power dispensed, and other possible characteristics. The device 1 for treating combustion fumes F comprises a tubular body 2 that has an axis Z.

The axis Z corresponds to the axis of the tube T, for discharging fumes F, in which the device 1 is positioned .

The axis Z also substantially corresponds to the direction in which the combustion fumes F are discharged .

The tubular body 2 has an outer surface S and an inner surface I, in contact with the combustion fumes F.

The tubular body 2 comprises at least one filtering element 7 that is completely inside the tube T for discharging fumes F or inside the tubular body 2.

That is to say, the bulk defined by the filtering element 7 is established based upon the dimensions of the tube T for discharging the fumes F or upon the dimensions of the tubular body 2, without requiring specific housings to be created for the at least one filtering element 7, with dimensions or bulk that are greater with respect to those of the tube T for discharging fumes F or to those of the tubular body 2. The tubular body 2 has a cross section, perpendicular to the axis Z, which is substantially circular. The diameter of the cross section of the tubular body 2 depends on the type of fuel that is used to supply the heating apparatus.

Moreover, the diameter of the cross-section of the tubular body 2 substantially corresponds to the diameter of the section of tube T for discharging the fumes F.

Such a section has a diameter having dimensions that are substantially comprised between 80 mm and 300 mm. In particular, generally, for heating apparatuses supplied with pellets, the diameter of the tube T for discharging combustion fumes, and therefore of the tubular body 2, is comprised between 80 mm and 100 mm; for heating apparatuses that are supplied with wood, the diameter of the tube T for discharging combustion fumes, and therefore of the tubular body 2, measures around 150 mm; finally, for fireplaces and fireplace inserts, the diameter of the tube T for discharging combustion fumes, and therefore of the tubular body 2, can measure around 180 mm or 200 mm or 250 mm or 300 mm.

The tubular body 2, therefore, has a section with a diameter that is substantially equal to the diameter of the tube T for discharging fumes of the heating apparatus to which it is applied.

The tubular body 2 has one lower end 3 that is located at the inlet of the combustion fumes, in the body 2 itself, from the heating apparatus to which it is applied or from the tube T for discharging the fumes F connected to it.

In particular, the end 3 of the tubular body 2 can be connected to the tube T for discharging the fumes F. At such a lower end 3, the tubular body 2 has a coupling collar 4 that is substantially ring-shaped. The coupling collar 4 has a substantially circular cross-section .

The cross-section of the coupling collar 4 has dimensions that are slightly greater that the cross- section of the tubular body 2.

The dimensions of the cross-section of the coupling collar 4 are suitable for making a sealed connection between the device 1 and the heating apparatus and/or the tube T for discharging combustion fumes F to which the device 1 is applied.

The tubular body 2 has a side opening 5 and an element 6 for supporting at least one filtering element 7 and for closing the side opening 5.

The side opening 5 is positioned on the outer surface S of the tubular body 2 and extends substantially parallel to the axis Z.

The support element 6 acts as a door for closing the opening 5 itself.

The support and closing element 6 constitutes one portion of the tubular body 2 and/or of the tube T for discharging the combustion fumes F. The support and closing element 6, in one version of the invention, has two longitudinal sides and two transversal bases, the longitudinal sides extending substantially parallel to the axis Z of the tubular body 2, of which the support and closing element 6 constitutes one portion.

The transversal bases extend substantially perpendicular to the axis Z of the tubular body 2, of which the support and closing element 6 constitutes one portion .

Each longitudinal side of the element 6 has a length that is greater with respect to the length of each transversal base.

The side opening 5 has a shape that is substantially the same as, and corresponds to, the shape of the support and closing element 6, so as to be closed by the latter.

Basically, once the element 6 for supporting the at least one filtering element 7 is positioned so as to close the side opening 5 there is a return to the tubular-like appearance of the body 2 and/or of the tube T for discharging fumes F.

In such a way, the bulk obtained by the support and closing element 6 is equivalent to the bulk of the tubular body 2 or of the tube T for discharging combustion fumes F.

The support and closing element 6 and the side opening 5 can take up any suitable shape, without for this reason departing from the scope of protection of the present invention.

The support and closing element 6 is connected in a removable and/or openable manner to the tubular body 2 of the device 1 so as to make it possible to check and, if necessary, carry out maintenance operations on the device 1 itself.

The device 1 for treating combustion fumes F comprises at least one filtering element 7.

In one embodiment of the invention, there are two filtering elements 7. In one further version of the invention, there can be more than two filtering elements 7.

The at least one filtering element 7 comprises a catalytic filter that is equipped with an active agent that is capable of oxidising and or of carrying out a catalytic reduction of the potentially harmful substances present in the combustion fumes F.

The active agent comprised in the at least one filtering element 7 can be any material that is capable of oxidising and/or carrying out a catalytic reduction of the substances to be eliminated or reduced from the fumes F.

The active agent is selected from the oxidising and/or reducing catalysts, cerium and oxides thereof, rhodium, noble metal, a transition metal, or mixtures thereof.

In one version of the invention, the at least one filtering element 7 comprises a ceramic material made up of cordierite and/or mullite and/or silicon carbide and/or ceramic fibre.

Such a ceramic material can be a support for the active agent .

The ceramic material, in one version of the invention, comprises ceramic particles; such particles can have any shape suitable for having a wide catalytic surface and, at the same time, suitable for allowing the combustion fumes F to transit between the spaces left freed between the ceramic particles themselves.

The ceramic material, in further versions of the invention, can have different shapes, without for this reason departing from the protection of the present invention .

For example, the ceramic material, in one further version of the invention, can be honey-comb shaped.

In a further version, the ceramic material is coated with the active agent.

The active agent, in one version of the invention, is present in combination with the ceramic material, the latter acting as a support to the active agent itself. Concerning now the polluting substance carbon monoxide, the at least one filtering element 7 of the present invention converts it into carbon dioxide. Such an oxidation, in one version of the invention, is carried out by using cerium oxide.

Concerning now NOx, the at least one filtering element 7 of the present invention determines the catalytic reduction thereof.

Through the at least one filtering element 7, and in particular through its active catalyst agent, areas with high reactivity are created for the oxidation of carbon oxides and of unburned hydrocarbons, and a reduction environment is created that is suitable for eliminating nitrogen oxides. Such a reduction, in one version of the invention, is carried out by using rhodium.

The at least one filtering element 7 is fixed and constrained to the support and closing element 6. Such a constraint occurs through any fixing means suitable for this purpose.

The at least one filtering element 7 has an angle of inclination a with respect to the axis Z that is comprised between 30° and 60°. In particular, the angle of inclination a of the at least one filtering element 7 with respect to the axis Z is of 45°.

The at least one filtering element 7 has an angle of inclination β with respect to the axis Z that is comprised between 120° and 150°. In particular, the angle of inclination β of the at least one filtering element 7 with respect to the axis Z is of 135°.

The angles a and β can have the same or different size, according to the requirements. The angles a and β, as visible in figure 3, extend between the axis Z and the upper surface 12 of the filtering element 7.

In one version of the invention in which there are two filtering elements 7, one of them has an angle of inclination a whereas the other one has an angle of inclination β, having the values previously indicated. In such a way, one filtering element 7 forms an acute angle a, whereas the other filtering element 7 forms an obtuse angle β, with respect to the axis Z.

In one further version of the invention in which there are two filtering elements 7, they can both have an angle of inclination a or β, with the values that have been indicated previously. In such a way, both the filtering elements 7 form an acute angle a or an obtuse angle β, with respect to the axis Z.

In the version in which there are more than two filtering elements 7, they can be positioned on the support and closing element 6 respectively with an angle of inclination a or β according to the requirements .

In one version of the invention, the filtering elements 7 are alternately inclined by an angle a and by an angle β, respectively.

Through efficiency studies, it has been found that such values of the angles a and β are more efficient in terms of the filtered percentage of pollutants and particulates .

In one version of the invention, the tubular body 2 has more than one side opening 5, as visible by way of example, in figure 10. Each side opening 5 corresponds to the space that is suitable for the insertion of a filtering element 7. In such a version, the number of side openings 5 corresponds to the number of filtering elements 7.

If there are many side openings 5, the support and closing element 6 can have overall dimensions and shape that are suitable for defining the closure of all the side openings 5 simultaneously.

Alternatively, it is possible for the device 1 to be equipped with as many support and closing elements 1 as there are side openings 5 that they have to close.

The at least one filtering element 7 is moreover capable, from the mechanical point of view, of also blocking a percentage of particulate present in the combustion fumes F of the heating apparatus of the present invention, so as to substantially abate the emissions into the atmosphere of this type of pollutant as well.

Such a percentage varies according to the type and to the density of the catalytic filter present in the at least one filtering element itself.

Since it is constrained to the support and closing element 6, also the at least one filtering element 7 of the device 1 is removable from the latter and/or from the tubular body 2 and/or from the tube T for discharging the fumes F, so as to allow checking, cleaning and maintenance operations of the at least one filtering element itself and/or of the tubular body 2 to be carried out.

The at least one filtering element 7 can have a plan surface that is substantially quadrangular or having any other surface that is suitable for the purpose.

In order to meet the standards of the field, between the at least one filtering element 7 and the inner surface I of the tubular body 2 there is a passage of at least 15 mm. Consequently, the maximum dimensions of the at least one filtering element 7 depend upon the diameter of the section of the tubular body 2 and/or of the tube T for discharging the combustion fumes F.

In one version of the invention, the device 1 can comprise two filtering elements 7 having dimensions of around 150 mm in length by 110 mm in width.

The at least one filtering element 7 can also have different dimensions, without for this reason departing from the scope of protection of the present invention. Purely as an example, performance studies have been carried out using two filtering elements 7 with dimensions of around 147 mm in length by 112 mm in width, that are applied onto a tube T for discharging the fumes having a diameter of 150 mm, for an apparatus equipped with thermal power of 8kw. By using such parameters and such devices, the reduction percentage of carbon monoxide was equal to 38-45 % with respect to heating apparatuses without the device 1. Such a percentage can vary with the variation of the parameters and the dimensions of the apparatuses and of the tubes for discharging fumes.

The fact that the device 1 has filtering elements having an inclination that is optimised, makes it possible to not jeopardise the combustion, which could otherwise occur if the at least one filtering element 7 were to contrast the passage of the fumes with too much resistance .

At the same time, such an optimised inclination makes it possible to slow down the speed with which the combustion fumes F are discharged by a certain value so as to make it possible for there to be reactions of catalytic oxidation and/or reduction of the harmful substances and the holding of particulates contained in them.

The temperature of the combustion fumes F, which at most is around 600 °C or 800 °C according to the type of heating apparatus considered, optimises the catalytic oxidation and/or the reduction of the substances to be eliminated or reduced from the fumes F themselves.

The optimal temperature of such fumes further depends upon the type of filtering element 7 that is used.

In the steps in which the fumes F do not reach the temperatures at which catalytic oxidation and/or reduction of the substances to be eliminated or reduced from the fumes F occur, like for example when powered on or powered off, the at least one filtering element 7 only has a mechanical blocking function of the particulate contained in the fumes F themselves.

The at least one side opening 5 and/or the element 6 for supporting the at least one filtering element 7 and for closing the side opening 5 have at least one sealing gasket 8. Such a gasket is positioned along the perimeter of such at least one side opening 5 and/or of such a support and closing element 6 so as to ensure a tight seal between such elements.

The support and closing element 6 is fixed to the tubular body 2 through known fixing means, for example in the form of screws 9 and of corresponding seats 10. The support and closing element 6 can be fixed to the tubular body 2 through a hinge that allows it to open like a door.

The at least one filtering element 7 comprises a perimeter frame 11. Such a perimetral frame is constrained and fixed to the support and closing element 6.

The at least one filtering element 7 further comprises an upper surface 12 and a lower surface 13, with respect to the direction in which the fumes F are discharged.

The perimeter frame 11, the upper surface 12 and the lower surface 13 enclose the catalytic filter, and/or the active agent and/or the ceramic material according to the present invention.

The upper and the lower surfaces 12, 13 have any shape that is suitable for allowing the combustion fumes F to transit through them.

In one embodiment such surfaces 12 and 13 are grill- like.

Since the fumes F, due to the presence of the at least one filtering element 7, undergo slowing down, such a slowing down determines a greater thermal radiation of the heat of the fumes F themselves. In such a way, the fluid, in this case air, in contact with the tubular body 2 is heated more and consequently the heat exchange between the fumes F and the surrounding fluid is increased.

In one version of the invention, the tubular body 2 comprises, at its outer surface S where the support and closing element 6 is not positioned, an outer shell 14 that covers the tubular body 2 itself defining a second wall .

Such an outer shell 14 is positioned at a certain distance from the outer surface S of the tubular body 2 and/or from the tube T for discharging fumes F.

The outer shell 14 is made from the same material from which the tubular body 2 and/or the tube T for discharging fumes F are made.

The outer shell 14 defines at least one gap 15.

The at least one gap 15 is arranged between the outer surface S of the tubular body 2 and the shell 14.

Since the fumes F, due to the presence of the at least one filtering element 7, undergo slowing down, such a slowing down determines a greater thermal radiation of the heat of the fumes F themselves. In such a way, the fluid present inside the at least one gap 15 is heated more and its circulation along the wall in contact with the combustion fumes F is consequently promoted.

In such a way there is an increase in the heat exchange between the fumes F, the fluid inside the at least one gap 15 and the fluid, in this case air, externally in contact with the shell 14.

Such a shell 14 takes up the shape of the support and closing element 6 and copies it along at least part of or the entire outer surface S of the tubular body 2. In this embodiment, therefore, the heat exchange with the exchange fluid is greatly increased, since there is a greater exchange surface with the vector fluid, for example water or air.

At the same time, the bulk defined by the tubular body 2 is minimised, so as to correspond to the space occupied by the tube T for discharging the fumes F itself .

Another embodiment of the device for treating combustion fumes F according to the present invention is illustrated in figures 5, 6 and 7.

In the description of this embodiment the same reference numerals as the previous embodiment have been used to identify the same parts or components.

In this embodiment, the device 1 is substantially the same as the one described for the previous embodiment. The device 1 indeed comprises a tubular body 2.

In one version, the tubular body 2 comprises at least one side opening 5 and an element 6 for supporting at least one filtering element 7 and for closing the at least one opening 5.

The device 1 also comprises at least one filtering element 7. The phenomena already described for the previous embodiment occur inside the latter.

Such at least one filtering element 7 is connected so as to be able to be rotated with respect to the support and closing element 6 or with respect to the tubular body 2 or with respect to the tube T for discharging the fumes F.

The support and closing element 6 or the tubular body 2, indeed, has rotating connection means 20, to the at least one filtering element 7, which allow the at least one filtering element 7 to rotate with respect to the support and closing element 6 or with respect to the tubular body 2.

The rotating connection means 20 comprise a fork 21 for supporting the filtering element 7 and a pin 22, which is equipped with a first end, fixed to the fork 21, and a second end, on which a knob 24 is fixed.

The rotating connection means 20 further comprise a bush 23, which is fixed to the support and closing element 6 or to the tubular body 2 for supporting the pin 22 in a rotary manner. The pin 22, therefore, rotates inside the bush 23. In particular, the pin 22 connects the fork 21, and therefore the at least one filtering element 7, in a rotating manner to the knob 24.

The pin 22 is actuated by a user from outside through the knob 24.

The at least one filtering element 7, through the rotation of the rotating connection means 20, can rotate by around 90°.

Such a rotation makes it possible to vary the inclination of the at least one filtering element 7 so that its upper and lower surfaces, 12, 13 can lie on a plane that is parallel or transversal with respect to the axis Z.

In particular, in the case in which the upper and lower surfaces 12, 13 lie on a plane that is parallel with respect to the axis Z, the combustion fumes F freely pass through the tube T so as to be discharged, without being slowed down by part of the at least one filtering element 7.

In the case in which, on the other hand, the upper and lower surfaces 12, 13 lie on a plane that is transversal with respect to the axis Z, the combustion fumes are forced to pass through the at least one filtering element 7, thus being slowed down and purified. In particular operation conditions or requirements, the upper and lower surfaces 12, 13 can have an intermediate position, determining the filtration of a part of the fumes F and the free discharge of another part of the fumes themselves.

Such a rotation can occur in particular operation conditions, like for example when the heating apparatus, to which the device 1 of the present invention is applied, is powered on, or in the case in which there is a failure of the at least one filtering element 7.

In the version in which there are two filtering elements 7, they can both be of the rotating type or one may be of the rotating type and one may be of the fixed type.

In the version in which there are more than two filtering elements 7, they can be fixed and/or rotating in any combination.

There are also friction means (not illustrated) which tend to keep the pin 22 and the at least one filtering element 7 in the predetermined position. Such friction means can be automatically foreseen inside the bush 23. At the knob 24 or at the bush 23 there are indication means (not illustrated) for example in the form of a graduated scale or of an indicator arrow, that are capable of indicating in which rotation position there is the at least one filtering element 7 and, possibly, its degree of rotation.

The rotation of the rotating connection means 20 can be manual or automatic, in the case in which the heating apparatus and/or the device 1 are provided with an electronic control and operation management unit of the known type.

The present invention further has a heating apparatus that is equipped with the device 1 for treating combustion fumes F, as described previously.

The invention, thus conceived, makes it possible to obtain important technical advantages.

Firstly, when passing through the at least one filtering element 7, a relevant percentage of particulate is subtracted from the combustion fumes F and, due to the active agent comprised in the catalytic filter, a further relevant percentage of polluting substances is subtracted.

Moreover, during such a passage, the fumes F are slowed down, thus ensuring a greater heat exchange with the fluid surrounding the tubular body 2 and/or the gap 15 and the outer shell 14.

The device 1 has a compact structure with a limited bulk, and it is not larger than that of the tube T for discharging combustion fumes F of apparatuses without the device 1. In such a way, it is ensured that the appearance of such apparatuses is pleasing, whilst at the same time ensuring an improvement in terms of impact on the environment.

The appearance of the present invention is particularly appreciated, since the device 1 is housed on the tubes for discharging the fumes which are inside rooms or houses, so as to convey such fumes towards the open environment surrounding the building.

The device 1 does not require particular installation activities. Indeed, it can be installed in both new apparatuses, which are equipped with such a device, and in pre-existing heating apparatuses.

The device 1 is indeed effectively and completely integrated inside the tube T for discharging the combustion fumes F.

The device 1, and the heating apparatus equipped with such a device 1 are cost-effective, they are constructively and operatively simple and they can be made with means and technology that are known in the field.

The energy consumption and the operation costs can be compared to those of known apparatuses without devices for treating combustion fumes. It has thus been seen how the invention achieves the proposed purposes.

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