EP1275902A2 - Air and exhaust gas duct suitable for the active cleaning of the outer surface of a roof - Google Patents

Abstract

Device for guiding air and exhaust gas, especially for a gas-heated heat-generating device, comprises at least one exhaust gas pipe (2) and at least one, preferably concentric, air inlet pipe (3). At least the surfaces of the device exposed to exhaust gas and/or weathering are at least partially coated or made of a material, especially a ceramic or copper-containing material, which is inert to the combustion air and/or exhaust gas. An Independent claim is also included for the use of a gas-guiding device, especially an exhaust gas pipe, coated with a ceramic or copper-containing material as an insert in or attachment on an air- and exhaust gas-guiding device. Preferred Features: Wind and weather protection (5) is provided in the form of at least one gas-guiding device guaranteeing spatial separation of the inlet air and exhaust gas flows. At least part of the device is made of sheet copper. A surface of copper-containing and/or ceramic material is profiled to increase the surface area. The ceramic material is titanium, especially titanium dioxide.

Description

The invention relates to a device for air and exhaust gas routing and Use of a gas guiding device according to the preamble of patent claims 1 or 9 and 10.

A gas guiding device, or an air and exhaust gas guide, is used in particular for fuel-heated heat generator needed to ensure that the for Combustion supply air as well as that required for combustion resulting exhaust gas without impairing the effectiveness of the combustion or the environment can be supplied or removed.

So far, especially for gas-heated heat generators, there have been vertical ones Roof ducts with one exhaust pipe and one, especially concentric arranged supply air pipe known, in which the exhaust gas in an inner pipe and in the annular gap formed between the inner and supply air pipes around the exhaust pipe the combustion air for the device is promoted.

These roof guides are made with a relatively thick-walled exhaust pipe made of an aluminum alloy, such as AlMgSi, the dimensions for one effective operation of a heat generator that meets a heating requirement of is designed for a maximum of 30 kW, with an exhaust pipe diameter of 80 mm and a supply air pipe diameter of 130 mm with wall thicknesses of up to 2.5 mm are common.

The relatively large wall thickness of the exhaust pipe is due to a surface erosion due to corrosive components in the combustion air and exhaust gas. On this way, based on normal through the combustion air and the exhaust gas corrosion ensures an acceptable service life so that additional corrosion protection is not necessary.

Because this concentric air / exhaust system acts like a heat exchanger where part of the thermal energy of the exhaust gas is released into the combustion air, the exhaust gas is continuously cooled down to the mouth. In particular when the outside temperature is cold, this system is a problem Circumstances below the dew point temperature, so that it is in the range of Mouth of the exhaust pipe to form condensation. With a cold one Outside temperature, the formation of condensation occurs increasingly. Since the Mouth area, so the end of the exhaust pipe the lowest Surface temperature, the damp exhaust gas is most likely to condense here and there is a discharge of the wet precipitation. This sits up the surrounding roof surface and leads when using conventional Roof ducts in double pipe construction made of aluminum pipes to a relative high aluminum discharge, which is optically very annoying on the roof surfaces deposits. This aluminum discharge consists among other things of ceramic Alumina components and is from the roof surfaces with which it is easy connects, or penetrates into them, only very lengthy or practically only mechanically to remove.

To avoid this disadvantage, a system is therefore in DE 298 23 836 proposed that instead of or in addition to a conventional system Thin-walled stainless steel insert tube made of a chrome / nickel alloy manufactured and is largely corrosion-resistant. This Execution has worked well in practice, but still includes some Disadvantage. The stainless steel exhaust pipe is made of smoke and heat resistant Stainless steel alloy made to withstand the corrosive influences, especially the exhaust gas withstand. However, it is relatively expensive and complex to manufacture. moreover discharge of condensed exhaust gas cannot be avoided with this device and there is no possibility of active cleaning this or already existing pollution.

The object of the present invention is accordingly a device for air and Develop exhaust gas routing according to DE 298 23 836, or a To provide gas guiding device, which the formation of, in particular optically disturbing, deposits on the roof duct surrounding Roof surfaces prevented, which is also inexpensive and durable as well as if necessary can be retrofitted.

This object is achieved by a device for air and exhaust gas routing Claim 1 or by use according to claims 9 and 10 solved.

An essential basic idea of the invention is the knowledge that with Internals or surface coatings made of special materials an active Cleaning effect of the roof surface can be achieved.

It has been shown that in particular copper or copper-containing materials effect cleaning, but this also ceramic materials are suitable so that an arrangement of these materials in the exhaust gas Area of the roof duct is predestined.

In particular, the object of the invention is therefore achieved by a device for Air and exhaust gas routing, especially for a gas-heated heat generator, with at least one exhaust gas and at least one, preferably concentrically the exhaust air pipe arranged solved, wherein at least exhaust gas and / or Surfaces of the device exposed to the weather are at least partially opposite Combustion air and / or exhaust gas are essentially inert or weak reactive, in particular ceramic and / or copper-containing material coated or are made from it.

Furthermore, the task is achieved by using a ceramic and / or copper-containing material coated or produced from it, in particular an exhaust pipe, for use in an air and exhaust gas routing device and a device for air and exhaust gas routing solved.

An important point of the invention is that the erosion effect of the exhaust gases leads to the fact that the smallest particles are released from a surface, which are then deposited together with dirt particles on the roof surface. If the surface (s) of the gas guiding device or the device for air and exhaust gas guidance, which are exposed to corrosive gases, in particular exhaust gases or oxygen-containing combustion air, are made of copper, copper particles are accordingly deposited on the roof surface. Unlike ceramic aluminum particles, such as Al ₂ O ₃ , the copper particles do not bond to the surrounding roof surface, but are rinsed off together with the dirt for which they serve as a sink, and a further approach is prevented. This is based on the one hand on the fact that existing dirt absorbs on the surface of the copper particles and on the other hand on the fact that copper as a semi-precious metal does not tend to form ceramic components due to its position in the voltage series. In addition, copper forms a patina in the presence of carbon dioxide, which protects the underlying metal, such as an exhaust pipe, from further destruction. In this respect, the CO ₂ -containing atmosphere of the exhaust gases advantageously forms a passivation layer which increases the service life on the copper components of the device according to the invention, but without preventing copper-containing particles involved in the active cleaning action from being carried away, for example by washing out.

According to a further embodiment of the invention, the device for air and Exhaust gas routing continues to provide wind and weather protection in the form of at least one Gas guiding device on the spatial separation of air flows from supply air and ensures exhaust gas, at least parts of which with ceramic and / or copper-containing material coated or made from it.

This proves to be particularly advantageous because the wind and Weather protection for those components of the device for air and Exhaust gas routing is one where the highest formation of condensation takes place, and which also includes atmospheric weather influences, such as Rain and snow are exposed, which on the one hand have a corrosive effect and on the other are suitable for transporting dirt onto the surrounding roof surfaces.

According to a further embodiment of the invention, at least parts of the Device, in particular the wind and weather protection and the Gas guiding device (s) made from copper sheet. Alternatively, these parts also painted, sprayed or otherwise coated with copper colors be, including a copper-containing film coating within the scope of the invention falls.

At this point it should be mentioned that the device for air and exhaust gas routing including complete wind and weather protection, for example in the form of Molded sheets can be made of copper, but also for reasons of cost can be dispensed with, which are located within a building and therefore Components of air and air largely insulated from cold temperatures Exhaust duct made from copper while outside a building existing parts of the device are preferably coated at least with copper. Depending on the requirement, it may even be sufficient if the exhaust pipe in itself, i.e. at least its inner surface and the wind and weather protection, shortly weather protection, coated with copper-containing material or from it is made, although both the durability and the aesthetic effect is improved in a full copper version.

According to a further embodiment of the invention, the copper sheet has one Wall thickness in the range of 0.1 mm to 3.0 mm, preferably in the range of 0.5 mm to 2.5 mm and particularly preferably in the range from 1.0 mm to 2.0 mm.

Wall thicknesses of 0.1 mm are possible, for example, where copper sheet is used as a foil, which can be applied, for example, while in the area particularly aggressive exhaust gases, for example through sulfur dioxide or Chloride admixtures in the exhaust gas wall thicknesses of up to 3.0 mm are possible, albeit in the usual environment, wall thicknesses of the copper sheet in the range of 1.0 mm to 2.0 mm.

Compared to a conventional version with aluminum tubes the lower necessary wall thickness of copper pipes is advantageously in it justifies that copper is a semi-precious metal with a pronounced Passivation tendency trades while aluminum under exhaust gas conditions too a high surface removal tends.

According to a further embodiment of the invention, a surface is made of copper and / or ceramic material to enlarge the surface profiled. An increase in the surface can also be done by several individual pipes, a network or a honeycomb gas guiding device from one copper and / or ceramic material can be realized, such Profiling or surface enlarging agent preferably only in the Exhaust pipe, preferably at its outer end or on the weather protection are provided. This avoids that the flow resistance is unnecessary is increased. The advantage of a larger surface of the copper-containing parts lies in that the active cleaning effect of the copper with an increasing Surface of the same increases.

According to a further embodiment, instead of or in combination with Copper uses a ceramic material that has titanium dioxide in particular. Such a ceramic is extremely resistant and already shows in small Layer thicknesses have a very good resistance to corrosive influences. Titanium dioxide, as a thermodynamically very stable connection, acts at this point, when it is carried out, similar to copper as an absorption germ, caused by rain can be washed off well from a roof surface. In addition, the Use the ceramic material to remove the surface from the exhaust pipe minimize and thus already prevents contamination of roof surfaces largely before.

The principle active cleaning effect of titanium compounds and in particular of titanium dioxide is based on different modes of action. So in addition to the photocatalytic property of titanium dioxide the effects of hydrophilization and exploited the hydrophobization of surfaces. With a view to Dirt deposit and - according to the invention - especially with regard to a These effects have an effect on dirt removal, namely depending on the condition of the titanium dioxide a hydrophilization or a hydrophobization, together with the Photo catalysis at the same time and can support each other. The The decision as to which of these effects is preferred can be made using the respective cleaning problem. This is discussed in more detail below received.

The main influencing variable, which is in a hydrophilization or in a Hydrophobization is used to create a surface with a certain defined contact angle with water. Regarding one The cleaning effect is crucially important here whether it is hydrophobic or hydrophilic surfaces.

In the case of hydrophobic surfaces, such as those in exhaust pipes through a low but unavoidable exhaust gas particle discharge, such as soot, are present, there is a large contact angle of 60 °, preferably 80 ° and larger beneficial for a cleaning effect. This is so pronounced that water contracts into single drops on such a surface, which have the shape of spherical sections. The spherical sections have a comparatively large height and a comparatively small footprint. The Adhesive force that acts between the water and the surface is relatively small, so that the water leaves the surface readily and relatively completely, especially if this is supported by an air or exhaust gas suction. The Drops slide easily on these surfaces.

According to the invention, therefore, at least the inside of the exhaust pipe is one Provided coating that a hydrophobization of the inner surface of the Exhaust pipe causes. According to the invention, a ceramic is provided for this purpose has amorphous titanium dioxide.

By ensuring that condensate on the inside of an exhaust pipe is easy to roll off, on the one hand it is avoided that aggressive constituents in the exhaust gas, such as H ₂ SO ₄ , H ₂ SO ₃ , HNO ₂ or HNO _3, can attack the inner surface of the exhaust pipe. In addition, due to the generally vertical position of the exhaust pipe at a roof penetration, a beading down is favored, so that the water drops in warmer areas, ie, evaporate again closer to the heat generator and be made accessible to a gaseous discharge. Another effect that comes into play is that water that drips off can rinse off existing dirt, so that a self-cleaning effect also comes into play inside an exhaust pipe.

Depending on the material exposed to the weather, areas can also be exposed Amorphous titanium dioxide can be provided. The amorphous is also preferred here Titanium dioxide integrated in a ceramic matrix. As a rule, however, it will for those surfaces that are exposed to the weather to hydrophilic surfaces act so that there is a hydrophilization for these areas. According to the invention, this is achieved by using a ceramic that is crystalline Titanium dioxide has, especially after exposure, extremely small contact angles below 5 °, in particular even below 1 °. Coated according to the invention Surfaces which have titanium dioxide in the anatase crystal form are preferred. This are self-cleaning due to a small contact angle. This is on it due to the fact that the adhesive force between hydrophilic surfaces Due to the small contact angle, water and the surface appear similar to the Use of chemical substances, such as surfactants, reduced becomes. The result is an easy drainage of water. Through this expiration already existing impurities rinsed off, so that a slow but constant cleaning of the roof surface or the area exposed to the weather, for example an exhaust gas, air or generally gas guiding device surface takes place.

Another beneficial effect of using titanium dioxide in ceramics, Areas exposed to the weather in particular consist of photoactivity of titanium dioxide. The photoactivity is a semiconductor effect, which is preferred on anatase crystals occurs. The level of photoactivity can be determined by the size, the type of Formation and doping of the crystals can be influenced. With photoactivity is photocatalysis and in the broadest sense an oxidation, in which, in particular organic substances, catalytically decomposes and becomes End products carbon dioxide and water are broken down. Here are under the Influence of UV radiation, especially long-wave UV radiation, on Titanium dioxide acts, generates OH radicals, which in turn are reactive and with, especially organic, water impurities react and oxidize them. Since this is a catalytic process, there is no consumption of Titanium dioxide instead.

The contaminants are advantageous when adsorbed on titanium dioxide oxidized. It is therefore advantageous if the surface is made of ceramic material Enlargement is profiled the same. The adsorption capacity Titanium dioxide, which is preferably present on the surface of the ceramic layer, is thus increased and degradation accelerated. An essential synergy effect between a hydrophilized surface on which water contaminants are good can roll off and the photocatalytic effect of titanium dioxide on the Surface is that a shielding effect caused by a high Dirt concentration can be caused, and the accessibility of the Would prevent titanium dioxide for UV radiation, preferably from daylight is avoided. With heavily soiled surfaces an additional Irradiation with ultraviolet light may be provided, however, depending on the can only take place temporarily in the respective circumstances. Furthermore, it can Titanium dioxide, for example, be loaded with metal complexes. For example, this is then advantageous when it comes to the preferred degradation of a specific pollutant goes.

In summary, it can be stated that hydrophobized with titanium dioxide or hydrophilized surfaces great advantages in the self-cleaning of Offer surfaces. The interaction of hydrophilized or hydrophobized and at the same time photocatalytically active surfaces can have a wide variety Eliminate cleaning problems, but at least significantly mitigate them. This works to the effect that surfaces provided with titanium dioxide, preferably in Form of amorphous titanium dioxide on hydrophobic surfaces or with crystalline surfaces, preferably anatase crystals, have significantly fewer surfaces dirty, easier to clean, self-cleaning, fog-free and even have an anti-fouling effect. This is due to the photocatalytic effect of Titanium dioxide favors. Surfaces coated according to the invention thus have clear advantages over conventional surfaces.

According to a further idea of the invention, one with ceramic and / or copper-containing material coated or produced from it, in particular an exhaust pipe or a wind and weather protection in one device used for air and exhaust gas routing.

According to the invention, a aforementioned device is suitable for self-cleaning Roof surfaces.

Such a device is advantageous in the field of wind and Weather protection, the surface of these components, if they already exist exist or do not have to be replaced, but additionally with these Materials can be loaded. If necessary, also a replacement to think of the existing components as another advantage of The device according to the invention is that already installed air and Exhaust gas ducts with the corresponding additional inventive Components can be equipped. So can be tubular Copper pipe straps, which are with screw connections or with a quick fastener, for example, by clamping or plugging, can be easily provided Mount the area of the air pipe. Existing systems can quickly and easily can be retrofitted inexpensively without influencing the system function. Readjustments to the system are therefore unnecessary.

Further embodiments of the invention result from the subclaims.

Fig. 1

eine schematische Dachdurchführung mit einer Ansaughaube und einem Witterungsschutz.

The invention is described below on the basis of exemplary embodiments, which are explained in more detail with reference to an illustration. Here shows:

Fig. 1

a schematic roof duct with an intake hood and weather protection.

In the following description, parts that are the same and have the same effect the same reference numbers are used.

Fig. 1 shows schematically a part of a roof with a roof duct 1 for a device for air and exhaust gas routing, which consists of an exhaust pipe 2 and a supply air pipe 3 which is concentric therewith as well as an intake hood 4 and a Weather protection 5 and optionally a pipe 6 surrounding the supply air pipe 3 composed. In the circle depicted "inside the roof" are the Flow directions 7 of the incoming air flowing through the suction hood 4 and the shown below the weather protection 5 emerging exhaust gas.

According to a first exemplary embodiment, only the exhaust gases are exposed Components, i.e. the exhaust pipe 2 from a thin-walled copper pipe manufactured. Weather protection 5 and optionally the intake hood 4 as well as, also optional, the tube 6 can also be made of a thin-walled copper sheet consist.

According to a second embodiment, all components that are above the Roof are made of copper, the supply air pipe 3 from one thin-walled copper tube with about 1 mm wall thickness, while the Exhaust pipe 2 has a wall thickness of approx. 2 mm. The intake hood 4 and the Weather protection 5 are also made of copper, the sheet 1 mm Has wall thickness and is profiled so that it is also higher Withstands wind speeds or a snow load.

According to a third exemplary embodiment, there are 3 in the area of the supply air pipe additional tubular elements inside or outside in the form of a tube 6 arranged, the exhaust pipe with a extending in the longitudinal direction Groove profile is formed to enlarge the surface thereof.

According to a fourth embodiment, the inner surface of the exhaust pipe 2 provided with a layer of amorphous titanium dioxide, while the outer Surface of the supply air pipe 3, the suction hood 4 and the weather protection 5 are provided with a ceramic layer, the titanium dioxide crystals in the crystal form Anatase. Furthermore, the surrounding roof areas are also with a Anatase coating.

From the above it can be seen that the present invention is not just a device, but also a method of treating exhaust gas to avoid Soiling of roof surfaces affects.

At this point it should be noted that all the parts described above are for themselves seen alone and in any combination, especially those in the drawing shown details are claimed as essential to the invention. amendments the skilled worker is familiar with this.

LIST OF REFERENCE NUMBERS

1

Roof outlet

2

exhaust pipe

3

supply air duct

4

suction hood

5

weather protection

6

pipe

7

flow directions

Claims (10)

Device for air and exhaust gas routing, in particular for a gas-heated heat generator, with at least one exhaust pipe (2) and at least one supply air pipe (3), preferably arranged concentrically to the exhaust pipe (2),
characterized in that
at least exhaust gas and / or surfaces of the device exposed to the weather are at least partially coated with, or produced from, material which is inert to combustion air and / or exhaust gas, in particular ceramic or copper-containing material. Device according to claim 1,
characterized in that
a wind and weather protection (5) in the form of at least one gas guiding device is provided, which ensures a spatial separation of flows of supply air and exhaust gas, at least parts of which are coated or made of ceramic or copper-containing material. Device according to one of claims 1 or 2,
characterized in that
at least parts of the device, in particular the gas guide device (s), consist of copper sheet. Device according to claim 3,
characterized in that
the copper sheet has a wall thickness in the range from 0.1 mm to 3.0 mm, preferably in the range from 0.5 mm to 2.5 mm and particularly preferably in the range from 1.0 mm to 2.0 mm. Device according to one of the preceding claims,
characterized in that
a surface made of copper and / or ceramic material is profiled to enlarge the surface. Device according to one of claims 1, 2 or 5,
characterized in that
the ceramic material has titanium, in particular titanium dioxide. Device according to one of the preceding claims,
characterized in that
the interior of the exhaust pipe (2) and / or surfaces exposed to the weather have amorphous titanium dioxide. Apparatus according to claim 6,
characterized in that
surfaces exposed to the weather have crystalline titanium dioxide in the crystal form of anatase. Use one with ceramic and / or copper-containing material coated or produced from it, in particular Exhaust pipe (2), for use in and / or approach to an air and Exhaust gas routing device. Use of a device according to one of claims 1 to 8 for especially self-cleaning roof surfaces.

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