DE202012009845U1 - Domestic fireplace with particle filter - Google Patents

Abstract

Domestic fireplace, in particular a wood-burning stove, fireplace or tiled stove, comprising a combustion chamber with an openable door, a combustion air supply and an exhaust pipe connection for supplying the heating gases from the combustion chamber through the exhaust pipe connection to a chimney, between the combustion chamber (2) and the exhaust pipe connection (6) at least one fire-resistant particle filter (8) is arranged, which flows through at least part, preferably of all hot gases from the combustion chamber (2), characterized in that the at least one particle filter (8) is formed from a zirconium oxide comprising ceramic element, in particular plate-shaped ceramic body.

Description

The invention relates to a domestic fireplace, in particular a stove, a fireplace or a tiled stove, comprising a combustion chamber with an openable door, a combustion air supply and an exhaust pipe connection to supply the heating gases from the combustion chamber through the exhaust pipe connection a chimney, wherein in the flow direction of the hot gases between the combustion chamber and the exhaust pipe connection at least one fire-resistant particulate filter is arranged, which flows through at least from a part, preferably of all hot gases from the combustion chamber / can flow through.

The term "hot gases" are understood to mean all products which escape during a combustion process and escape through an exhaust pipe connection, thus in particular all exhaust gases and flue gases, in particular also with particulate fractions, such as, for example, B. entrained in the exhaust stream Russ, dust or ash.

Such fireplaces are well known in the art and are usually used in addition to purely decorative aspects for heating apartments or houses, for which in such fireplaces various fuels are burned, such as wood, coal, wood or coal briquettes or other pressed fuels such for example pellets.

The resulting in the operation of such a fireplace hot gases, which include the combustion products and heated air in the context of this description of the invention, heat the fireplace as a whole.

To improve the efficiency of such fireplaces and to reduce pollutant emissions, it is known in such fireplaces to use particulate filters, which are traversed by the hot gases.

Thus, when arranging a flowed through particulate filter in the fireplace, the resulting pollutants during combustion, such as soot, ash or dust particles or gaseous pollutants, on and in the fire-resistant and heated by the fire and / or hot gases, if necessary, until annealing heated particulate filter are deposited and burn by heating in direct or indirect contact with the filter.

Gaseous pollutants can be heated within the fire-resistant particulate filter by the close contact with the filter material so high that they largely decay into harmless combustion products.

In addition to the filter property, such a fire-resistant particle filter forms a further element in the region of the combustion chamber, which is heated and thus also contributes to the heat transfer to the environment of the fireplace. Thus, the efficiency of such inventive fireplaces alone by the provision of the particulate filter over the known in the art fireplaces can be increased.

In a previously known arrangement, filter elements made of an alumina ceramic, silicon carbide ceramic or cordierite are usually used as a particle filter or ceramic element forming this. Although these materials fundamentally withstand the stresses in a fireplace, but possibly not permanently, so that such a ceramic element must be replaced, which leads to operating costs and / or maintenance costs in addition to the fuel. This could be because z. B. ceramic elements of cordierite deform over time and tear usual aluminum oxide ceramics or those of silicon carbide.

It is therefore the object of the invention to provide particle filters made of ceramic, which are essentially as easy and inexpensive to produce as the previous, but which can be used permanently or at least have a longer period of use.

This object is achieved in that the at least one particle filter is formed from a zirconium oxide (ZrO ₂ ) comprising ceramic element, in particular plate-shaped ceramic body.

It is therefore essential for the inventive design of a fireplace that zirconium oxide in the ceramic material of a ceramic element is at least also present, thus thus represents at least an admixture with other ceramic materials.

It has been found that such ceramics comprising zirconium oxide as an admixture can provide a longer useful life, if not a completely permanent use, since zirconium oxide gives the ceramic element higher hardness, tear resistance, lower deflection, higher thermal shock resistance and better thermal shock behavior Comparison to other common materials.

Already the admixture of zirconium oxide in the ceramic material from which the ceramic element is made, even if zirconium oxide a Minorätsanteil the entire ceramic material represents, thus leading to an inventive design of the fireplace.

Such admixture may, for. B. in the range of 5 to 50 volume or weight percent, preferably 5-25 volume or weight percent based on the total ceramic mass.

In a ceramic element according to the invention as a particle filter can thus accumulate in this embodiment and also the embodiments described in a conventional manner particles that arise during the combustion process to the surface of the ceramic element and post-burn after reaching a sufficiently high operating temperature of the fireplace. Even at high operating temperatures in the fireplace or combustion processes in the ceramic element, the risk of cracking is significantly reduced due to the zirconia component.

Thus, a possible embodiment may provide that the ceramic element used as a particle filter is made predominantly of a ceramic material other than zirconium oxide, such as, for. Example of alumina and / or cordierite and / or silicon carbide and that the material has a reinforcing admixture of zirconium oxide. Already hereby stabilization can be achieved.

A contrast preferred embodiment, however, provides that a ceramic element is formed predominantly of zirconium oxide, in particular more than 50% zirconium oxide based on the total proportion of ceramic material.

An embodiment may even provide that a ceramic element is completely formed of zirconium oxide with respect to its ceramic material portion.

The reference to the ceramic material content should make it clear that in a ceramic mass, in particular for their production before sintering, in addition to ceramic materials, other supplements can be negotiated, such. As binders or the like.

Due to the predominant amount of zirconium oxide or even the complete formation of a particularly high quality of the ceramic element is achieved, d. H. The element is particularly resistant to closing and also withstands stronger temperature stresses, in particular temperature changes.

A possible development, which is applicable to all possible embodiments of the invention, can provide that a ceramic element is further mechanically reinforced by the addition of fibers. Such fibers, z. B. be added in a desired proportion of the sintered ceramic mass and thus increase the stability after sintering in addition.

The fibers can z. Example, be formed by alumina fibers, aluminum silicate fibers, carbon fibers, aramid fibers and preferably zirconia fibers, in particular each alone or as a mixture.

For the invention, it is essential that a ceramic element in all embodiments has a permeability to the hot gases and preferably forms a large surface area to deposit particles and other substances that are formed during combustion and afterburner.

For this purpose, it can preferably be provided to form a ceramic element as a foam ceramic. Can be made such a ceramic foam z. B. in that a combustible foam body, for. Example of PU soaked with the zirconia comprising ceramic material for production, dried and then sintered, after which a foam ceramic body remains, which forms a ceramic element according to the invention.

The sintering of a ceramic element of the invention can be carried out in its manufacture in a temperature range greater than 1300 degrees Celsius, preferably greater than 1500 degrees Celsius, regardless of whether it is a ceramic foam or other training. The higher the sintering temperature, the more durable is such a ceramic element.

A possible embodiment may also provide that a ceramic element is not made in its entire volume of the same ceramic material, but that it comprises at least two adjacent layers of different ceramic material, in particular those are arranged so that they are successively flowed through by the hot gases , Wherein at least one of the layers zirconium oxide comprises, in particular predominantly or completely in the sense mentioned above based on the ceramic material content.

Preferably, the arrangement of such at least two-layered ceramic element in the fireplace is such that a layer comprising zirconium oxide faces the combustion chamber and is therefore exposed to the fire or the hot oncoming hot gases. Even such a design has significant stability advantages, but may be made in part from conventional ceramic masses and would thus be cheaper to produce than one Ceramic element that would be made entirely from the zirconia-containing composition.

An embodiment may also provide for forming a ceramic element with a ceramic core that does not comprise zirconia or a lower level compared to a zirconia-comprising ceramic layer that completely surrounds the core.

A further embodiment may also provide for arranging a plurality of ceramic elements serving as particle filters in the flow direction one behind the other, in particular at a distance from each other through which the hot gases flow successively. Such several, in particular at least two ceramic elements may be formed of different ceramic materials or even the same ceramic materials. In such an arrangement, according to the invention, at least one ceramic element is designed such that it at least comprises zirconium oxide, in particular predominantly. In this case, it is particularly advantageous if at least the first ceramic element in the inflow direction of the heating gases is such a ceramic element according to the invention, which at least comprises zirconium oxide, in particular predominantly comprises it, or is designed according to one of the other embodiments described above.

In all embodiments, it can preferably be provided that the combustion chamber of the fireplace is closed at the top and that forms at least one ceramic element, the only heating gas permeable connection between the combustion chamber and the exhaust pipe connection.

So it can be ensured that all hot gases that are produced during operation of such a fireplace, must pass through the used as a particle filter at least one zirconia comprehensive ceramic element and only after passing through the exhaust pipe connection to the chimney and remove.

If, therefore, in connection with the described invention, it is said that the combustion chamber is closed at the top, this does not mean, of course, a hermetic conclusion, since in such a case the resulting heating gases can not pull off, but only that the combustion chamber upwards towards at least optically completely or largely completely closed and the hot gases can not escape unhindered by a conventional channel-like connection between the combustion chamber and exhaust pipe connection from the combustion chamber.

Here, rather, the hot gases must pass through the at least one ceramic element, which brings the invention advantageous effect of the afterburning and efficiency improvement with it.

It may also be provided in one embodiment that the combustion chamber, in particular in its upper region, has a continuously open or optionally openable and / or closable bypass opening to the exhaust pipe connection. In a constantly open bypass opening, therefore, only a portion of the hot gases is passed through the ceramic element, another part passes directly to the exhaust pipe connection. Thus, clogging of the ceramic element with particles from the heating gases is prevented even in the Anheizphase.

An openable and closable bypass opening has the advantage that it can be opened in the heating phase and can be closed after reaching an operating temperature, so that then all hot gases must pass through the ceramic element and an afterburning takes place. The closing can z. B. also be done automatically, especially time or temperature controlled.

In a development, it can also be provided that a ceramic element additionally has a catalytic coating. In the previously described embodiment of a plurality of ceramic elements arranged one behind the other, it may be provided that the first ceramic element in the flow direction is not catalytically coated, but at least one of the ceramic elements following in the flow direction.

In a further particularly preferred embodiment, which can be used alternatively or cumulatively with the aforementioned embodiments, it can also be provided that a ceramic element, in particular in an arrangement above the average door height, is inclined towards the door. Here, an arrangement above the average door height is understood to mean that at least the middle of the ceramic element, optionally its lower edge, is arranged above half the door height.

With an inclination toward the door, it is further understood that the particle filter or the ceramic element that forms it, with its essentially planar surface, is neither arranged exactly vertically nor horizontally, but in an angular range therebetween, so that the surface normal of the ceramic element is in Direction to the door points.

The arrangement can be designed such that the projection of the particulate filter is completely or at least partially within the door. This can be achieved, for example, if the imaginary surface normal of the particulate filter, which emanates from the geometric center of the surface of the particulate filter, also hits the geometric center of the door of the fireplace, in particular the geometric center of the glass of the door of the fireplace. Thus, it can be effected that a heated particulate filter optimally directs the resulting radiant heat in the direction of the door of the fireplace, so that the door is additionally heated from the inside by radiant heat and so on the one hand the efficiency can be improved and on the other hand, the tendency to foul the glass Door is reduced because any adhering particles on the door, such as soot, dust or ash can thus also be burned.

In a further embodiment, it may also be provided that the rear wall of the combustion chamber is inclined at least in the upper region out of the vertical out to the door, in particular such that the combustion chamber tapers uniformly at least up to the maximum height of the rear wall. The type of taper can change abruptly at the upper height of the rear wall, for example, especially if above the rear wall of an inventive particle filter with a deviating from the inclination of the rear wall inclination, in particular an even stronger tilt out of the horizontal is arranged.

In particular, it is possible to form from inventive prior art fireplaces according to the invention by an existing ceramic element is replaced by an inventive, which comprises in its ceramic material zirconium oxide, in particular predominantly or even completely.

An embodiment will be explained in more detail with reference to the single figure:

The 1 shows a fireplace 1 with a combustion chamber 2 that has a door to open 3 comprises, a combustion air supply 4 through a fire bowl 5 through and an exhaust pipe connection 6 to the resulting hot gases from the combustion chamber 2 through the exhaust pipe connection 6 to feed a chimney, not shown here.

Recognizable here is that the combustion chamber 2 next to the two side walls, not shown in this section, a rear wall 7 which is in the upper area towards the door 3 in its entirety, tilted out of the horizontal. The combustion chamber 2 is thus from the door, the two side panels, not shown, the rear wall 7 , the lower fire bowl 5 and like this 1 furthermore shows, in the upper rear region by a particle filter according to the invention 8th completely enclosed. The particle filter 8th is here according to the invention formed in the form of a plate-shaped ceramic element, wherein the ceramic material comprises zirconium oxide.

This results in this embodiment for the resulting hot gases no direct undisturbed transition from the combustion chamber 2 to the chimney connection 6 but the hot gases must in this embodiment of the invention rather completely by the refractory ceramic element 8th to the exhaust pipe connection 6 to get.

For a heating phase, however, here is still a closable and openable bypass opening 10 provided between a support surface 10a and a slide plate lying thereon 10b is realized. The sliding plate 10b is here by a lever construction 10c adjustable from the outside. By opening causes at least a portion of the hot gases, bypassing the ceramic element to the exhaust pipe connection 6 can get. Such a bypass opening can also be omitted.

In general, the mode of operation of the embodiment according to the invention is such that the ceramic element 8th by its arrangement in the upper rear region of the combustion chamber 2 both by the rising hot gases passing through the the element 8th flow as well as possibly through the flames in the combustion chamber 2 be heated directly, using ceramic element 8th can be glowing. With the ceramic element 8th Contacting or penetrating pollutants, such as particles or gases, can thus be burned as they pass through or are heated in such a way that they burn up after being combined with fresh oxygen in the Heizgasumlenkung.

Thus, with such a construction according to the invention of a fireplace both the efficiency can be improved as well as the pollution of the environment can be significantly reduced.

The afterburning can also be supported by the fact that z. B. the ceramic element 8th backward of air 9a can be flowed through an air duct 9 is supplied, in particular which also provides air for a disc flush.

Likewise, air can be from the same channel 9 via a feeder 9b in the back wall 7 the combustion chamber are fed into this.

In the upper rear area 13 the fireplace 1 Here is still an arrangement of at least one baffle plate 11 that flows downstream of the ceramic element 8th is arranged and leads to a damming of the hot gases. This flapper 11 is attached to the air duct here.

Claims (19)

Domestic fireplace, in particular a wood-burning stove, fireplace or tiled stove, comprising a combustion chamber with an openable door, a combustion air supply and an exhaust pipe connection for feeding the heating gases from the combustion chamber through the exhaust pipe connection to a chimney, between the combustion chamber ( 2 ) and the exhaust pipe connection ( 6 ) at least one fire-resistant particulate filter ( 8th ) is arranged, the at least a part, preferably of all hot gases from the combustion chamber ( 2 ) is flowed through / flowed through, characterized in that the at least one particulate filter ( 8th ) is formed of a zirconia comprehensive ceramic element, in particular plate-shaped ceramic body. Fireplace according to claim 1, characterized in that the ceramic element is formed predominantly of a zirconia deviating ceramic material, in particular of alumina and / or cordierite and / or silicon carbide, wherein this material for reinforcement zirconium oxide, in particular as a minority component, is admixed. Fireplace according to claim 1, characterized in that the ceramic element is formed predominantly of zirconium oxide. Fireplace according to claim 1 or 3, characterized in that the ceramic element is completely formed with respect to its ceramic material content of zirconium oxide. Fireplace according to one of the preceding claims, characterized in that the ceramic element is mechanically reinforced by the addition of fibers. Fireplace according to claim 5, characterized in that the fibers are formed by at least one of the following types: alumina fibers, aluminum silicate fibers, carbon fibers, zirconia fibers, aramid fibers. Fireplace according to one of the preceding claims, characterized in that the ceramic element is designed as a foam ceramic element, in particular by firing / sintering a soaked with a ceramic mass foam body. Fireplace according to one of the preceding claims, characterized in that the ceramic element comprises at least two layers of different ceramic materials, which are successively flowed through by the exhaust gas and of which at least one layer comprises zirconium oxide, in particular predominantly comprises or. Its ceramic material content is formed entirely of zirconium oxide. Fireplace according to claim 8, characterized in that a zirconium dioxide-comprising layer of the ceramic element faces the combustion chamber. Fireplace according to one of the preceding claims, characterized in that the ceramic element has a ceramic core of a ceramic material without Zirkonoxidanteil and an outer, completely surrounding the core layer of a zirconia comprehensive, especially predominantly or entirely zirconia comprehensive ceramic material. Fireplace according to one of the preceding claims, characterized in that the ceramic element has a ceramic core, of a ceramic material having a lower zirconium oxide than in at least one outer, the core completely surrounding layer of ceramic zirconia comprehensive material. Fireplace according to one of the preceding claims, characterized in that a plurality of serving as a particle filter ceramic elements are arranged one behind the other in the flow direction, in particular with a distance from one another and flowed through / flowed through whereby at least one ceramic element comprises zirconium oxide, in particular predominantly. Fireplace according to claim 12, characterized in that at least in the direction of flow of the hot gases first ceramic element zirconium oxide comprises, in particular predominantly comprises. Fireplace according to one of the preceding claims 12 or 13, characterized in that at least one ceramic element following the first ceramic element in the direction of flow has a catalytically active coating, but not the first ceramic element in the direction of flow. Fireplace according to one of the preceding claims, characterized in that the ceramic element is fired / sintered during its manufacture with temperatures greater than 1300 degrees Celsius, preferably greater than 1500 degrees Celsius. Fireplace according to one of the preceding claims, characterized in that the ceramic element has a catalytically active coating. Fireplace according to one of the preceding claims, characterized in that the ceramic element ( 8th ), in particular with an arrangement above the middle door height, to the door ( 3 ), in particular such that the projection of the ceramic element ( 8th ) completely or partially inside the door ( 3 ) lies. Fireplace according to one of the preceding claims, characterized in that the rear wall ( 7 ) of the combustion chamber ( 2 ) at least in the upper area from the vertical out to the door ( 3 ) is inclined, in particular such that the combustion chamber ( 2 ) at least up to the maximum height of the rear wall ( 7 ) evenly tapered. Use of at least one gas-permeable, zirconium-comprising, in particular predominantly comprehensive ceramic element as a particle filter through which the heating gases flow in a domestic solid fuel fired furnace.

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