EP2246621B1 - Method for reducing the amount of fine dust in the waste gas of a heating device - Google Patents

Description

The invention / innovation relates to a method for reducing the particulate matter in the exhaust air of a solid fuel burning heater, in particular a tile or wood stove, fireplace stove, pellet stove, a Festbrennstofiheizanlage or the like, wherein the flue gases are passed through a filter material in the exhaust duct of the heater.

From the prior art, it is basically known to arrange a filter material in the exhaust duct in a solid fuel burning heater, such as a pellet stove. This is for example DE 20 2007 017 100 U1 It is described here that particles from the exhaust gas stream, such as soot particles, are filtered out and thus the fine dust pollution is reduced.

DE 20 2007 017 100 U1 teaches an exhaust gas purification arrangement of a small fire place, wherein a filter section for filtering particles from the exhaust gas flow is provided in an exhaust outlet, wherein in the exhaust gas flow direction before or after the filter section an annealing section for reducing unburned gas components is arranged.

DE 35 22 820 A1 teaches a method and apparatus for reducing pollutant emissions from incinerators whereby the exhaust gases after the filter zone are post-combusted with the supply of secondary air and the filter fuel, when its effectiveness is no longer sufficient, is also burned and continuously replaced by a new filter fuel.

DE 195 23 866 A1 teaches a method for separating flue dust and organic pollutants from flue gases, wherein the flue gases are passed through a bed of coke and the exhausted coke is regenerated or incinerated at a temperature of 400-1000 ° C.

The invention / innovation is the object of a method for reducing the particulate matter in the exhaust air of a solid fuel burning heater with the features of the preamble of claim 1 and a related heating device such that both the filter material and in the course of filtering in the filtrate captured filtrate is disposed of in a simple and convenient way. Furthermore, it is an object of the invention to make the handling of the displacement of the filter material as user-friendly as possible, to keep the dangers during handling as low as possible, and to achieve the overall system with the simplest possible structure of the heater.

This object is solved by the features of claim 1 and the device according to claim 8. Advantageous developments of the invention will become apparent from the dependent claims 2-7 and 9-15.

As the core of the invention, it is considered that the filter material is at least partially co-incinerated in an advanced, at least low-carbon phase of the combustion of the fuel within the heater. The filter material, together with the filtrate applied to it in the filter material during use, reaches the combustion chamber of the heater after the main use phase and is burned there with the heat energy (glowing fuel) prevailing there. This represents a simple as well as effective and environmentally friendly variant of the disposal of contaminated with the pollutants in the form of the filtrate filter material.

The filter material can be arranged inside the furnace housing or outside, as long as a supply into the combustion chamber is possible.

The combustion process of a solid fuel burning heater can be roughly described in terms of five phases. In a first phase, the drying of the fuel takes place. In the second phase, the hydrocarbons are expelled from the fuel and then (third phase) is followed by a first incomplete combustion, since no optimal oxygen-to-carbon ratio has been set. In the subsequent phase (Phase 4), a complete combustion of the fuel takes place so that the oxygen supplied via the air can react completely with the released fuel gases. In a last, the fifth phase, the burning of the fuel takes place without flaming. In particular, in phases 4 and 5, the heat output of the heater is at the highest level. It has been found that there is an almost exclusive need for filtering, especially in phases 1 - 3, especially during the incomplete combustion phase (phase 3). In phases 4 and 5, in which either complete combustion or merely the fumigation of the fuel takes place, filtration is unnecessary according to the invention, since substantially no unburned hydrocarbons are formed, but only carbon dioxide. This makes it possible to decouple the filter material in an advanced, at least low-carbon phase, ie in the phases 4 and / or 5 from the heating process as a filter material itself and the combustion chamber to use it there as a fuel. The pollutant filtrate retained in the filter material during the operating phases 1-3 is in this way also supplied to the combustion chamber and thus to the combustion process, so that these initially filtered pollutants end up as fuel in the combustion chamber and are burned there.

The filter or filter material may preferably be constructed in several parts, so that after e.g. a first use of the heater not the entire filter or, the entire filter material is burned, but a successive combustion of the filter or the filter material takes place over several heating periods of the heater away. Usually, soot particles deposit on the filter surface directed towards the combustion chamber. By a partial combustion of the filter - thus its surface directed towards the combustion chamber - then the rest of the filter can work better, since its transmission resistance was reduced with the liberation of the superficially adhered soot particles.

In order to increase the user-friendliness of the device, it is advantageous to have the feeding of the filter material into the combustion chamber of the heater automatically carried out. Such an automatic feed of the filter material may for example be temperature-dependent, radiation sensor, flue gas sensor, lambda sensor, air flow sensor controlled and / or otherwise. Such sensors can detect whether the combustion process or the heating process is already in the fourth and / or fifth phase and thus initiate the feeding of the filter material into the combustion chamber. This can in principle be done in an electronically controlled way with a processor which receives the sensor signals and correspondingly evaluates and actuates actuators which initiate the displacement of the filter material in the way. Alternatively, this can also be realized electrically or mechanically. A mechanical example would be the use of a bimetal after reaching a predefined one. Temperature threshold via a mechanism to carry the filter material in the combustion chamber.

Alternatively, the feeding of the filter material into the combustion chamber of the heater can also be done by manual operation of an enabling device controlling handling device. For example For example, by observing the combustion process and / or by monitoring corresponding sensors, the operator of the heater can perceive the achievement of the fourth and / or fifth heating phase and then actuate a handle which actively or passively conveys the filter material into the combustion chamber.

In a preferred embodiment, the filter material is arranged in a separate filter chamber Such a filter chamber can serve, for example, to stockpile-like filter material, such as fine-grained filter material to stockpile. In the case of a filter chamber, it may be provided that a release device for releasing the filter material into the combustion chamber can be activated either on the filter chamber itself or between the filter chamber and the combustion chamber. The release device can be designed, for example, in the form of flaps, sliders and / or a sieve which is displaceable into a closure (filter material holding position) and a release position.

It is also advantageous to use a one-piece filter material instead of or in addition to a granular filter material. This makes it possible, for example, to hold the filter material positively or non-positively and release it via the activation of the release device at a specific point in time, so that the filter material can enter the combustion chamber.

In a further embodiment of the invention, it has proven to be advantageous if in at least a first baking phase (phase 1, in which the fuel dries) of the fuel, the flue gases or the exhaust air are conducted past the filter material. Especially in the initial phase of the heating process, it is desirable to achieve a certain triggering effect. The fact that the filter material is at least initially "decoupled" from the exhaust air duct is achieved; that the resistance to overcome the exhaust air in the exhaust duct has, is significantly reduced and thus an increased volume flow of the exhaust air is reached. Also, this decoupling and coupling function with respect to the filter material can be initiated automatically or manually by the influence or the perception of sensors, such as a temperature sensor. For example, from reaching a certain temperature threshold, the filter material can be coupled into the exhaust duct, as this temperature threshold either the short-term impending or already reaching the phase 2 (expulsion of hydrocarbons) indicates.

Another way to reduce the resistance to be overcome for the exhaust air in the exhaust duct is to actively suck and / or blow the flue gases through the filter material in a first firing phase. This can be achieved by arranging an externally driven turbomachine, such as a fan, either before or after the filter material.

This method can be realized by a heating device, in particular a tile or stove stove, fireplace stove, pellet stove, Festbrennstoffheizanlage, solid fuel water heater or the like, which has a connected to an exhaust duct combustion chamber in which a solid fuel is combustible. This heating device is characterized in that a filter device equipped with filter material for reducing the particulate matter in or on the exhaust duct is arranged and the filter material of the filter device in an advanced, at least low-phase of the combustion process of the fuel in the combustion chamber of the heater can be inserted. The filter device is preferably arranged adjacent to the combustion chamber, so that the path for the filter material present in the filter device into the combustion chamber is as small as possible. In addition, the filter device may comprise a filter chamber in which the filter material is arranged, wherein the Filter chamber is provided with a release device for releasing the filter material into the combustion chamber. This may be achieved structurally so that the filter material rests on the release device, for example, on a flap and the release device for gravity-induced introduction of the filter material in the combustion chamber or slidable under the filter material for this purpose, in particular, a horizontal slidably mounted on the filter material release device offers ,

Furthermore, it is advantageous if the filter and / or the filter material is provided with combustion-active inclusions. These deposits are intended to favor the combustion of the filter material.

In a further advantageous embodiment, the release device for releasing a clamping fit, which holds an integrally formed filter material is formed. This represents a simple structural measure, for example, the release device can engage in a recess of the filter material and be pulled out of the recess of the filter material for releasing the filter material. In general terms, this means that the release device holds the filter material, which is preferably integral in this case, in a positive and / or non-positive manner and releases this positive and / or non-positive connection by a release mechanism so that the filter material enters the combustion chamber.

According to a further advantageous embodiment of the invention, it is provided to connect a reservoir, which is equipped with filter material, to the filter device such that the filter material from the reservoir is regulated and / or controllably displaced into the filter device. This results in the advantage that after the filter material used for the combustion process in the filter device has been supplied to the combustion chamber, a refilling of the filter device is facilitated.

Furthermore, it is advantageous if the supply of the filter material into the combustion chamber of the heater is effected by manual actuation of a release valve controlling the handle. Also, the automatic supply of the filter material can be temperature-dependent and / or controlled by a flue gas sensor in the combustion chamber of the furnace.

Furthermore, the filter material may be arranged in a separate filter chamber. Preferably, a release device for releasing the filter material into the combustion chamber can be activated between the filter chamber and the combustion chamber.

The filter material may be both granular filter material, as well as one or more pieces. In the case of a multi-piece filter material this can be piecewise transferred over several heating cycles in the combustion chamber. Also granular filter material can be filled in the exhaust duct into a receiving element and the receiving element to release the filter material are opened in the combustion chamber. Preferably, a Federrastsperre is provided to release the filter material in the combustion chamber, which - when released - allows an opening on the filter chamber or an opening at a connection between the filter chamber and the combustion chamber.

The feeding of the filter material into the combustion chamber preferably takes place during a phase of complete combustion in which an oxygen supplied for combustion reacts almost completely with the fuel gases.

With regard to the heating device according to the invention, it is advantageous if the filter device is arranged adjacent to the combustion chamber. Basically, a release device, the displacement of the filter material in the Combustion chamber performs and / or initiated, advantageous. For example, the release device is horizontally displaceable under the filter material. Also, the release device may be formed sieve. Moreover, it is possible to form the release device for releasing a press fit, which holds the integrally formed filter material. In this case, the release device can engage in a recess of the filter material and be pulled out for release from the recess of the filter material. The release can in principle be controlled electronically, electrically or mechanically. The release device is preferably biased in a filter chamber closed position and / or filter material holding position. Also, the filter may be formed of several parts of a filter material.

Fig. 1:

ein Diagramm zur Darstellung des Verbrennungsprozesses bei Festbrennstoffen in fünf verschieden Phasen;

Fig. 2:

eine schematische Darstellung einer ersten Ausführungsform eines Heizgerätes;

Fig. 3:

eine schematische Darstellung eines Heizgerätes mit einer Filterüberbrückungsvorrichtung (Bypassleitung) in Filter-Aktivstellung;

Fig. 4:

eine schematische Darstellung des Abluftkanals mit Bypaßleitung einer Heizvorrichtung gemäß Figur 3 in Filter-Deaktivierungsstellung;

Fig. 5:

eine schematische Darstellung einer alternativen Ausfilhrungsform mit im Wesentlichen zwei Schiebernrtechanismen;

Fig. 6a-6d:

schematische Darstellungen des Abluftkanals eines Heizgerätes gemäß Figur 5 in den Stellungen "Filter deaktiviert" (Figur 6a), "Filter aktiviert" (Figur 6b), "Verlagerung des Filters in die Brennkammerposition" (Figur 6c) sowie "Filterwiederbefüllung" (6d).

The invention is explained in more detail with reference to embodiments in the drawing figures. These show

Fig. 1:

a diagram showing the combustion process in solid fuels in five different phases;

Fig. 2:

a schematic representation of a first embodiment of a heater;

3:

a schematic representation of a heater with a filter bypass device (bypass line) in filter-active position;

4:

a schematic representation of the exhaust duct with bypass line of a heater according to FIG. 3 in filter deactivation position;

Fig. 5:

a schematic representation of an alternative Ausformhrungsform with essentially two Schiebernrtechanismen;

6a-6d:

schematic representations of the exhaust duct of a heater according to FIG. 5 in the positions "Filter deactivated" ( FIG. 6a ), "Filter activated" ( FIG. 6b ), "Displacement of the filter in the combustion chamber position" ( FIG. 6c ) and "filter refill" (6d).

Introducing is in FIG. 1 a flowchart of the combustion process shown in solid fuel, wherein in a first phase I, the fuel 4 undergoes essentially a drying. In the subsequent phase II, the carbons are expelled from the fuel 4 and then in phase III incomplete combustion takes place in the heater 1. In phase IV, the process goes to complete combustion and then in phase V, the combustion of the fuel takes place without flaming.

According to the invention, a heating device 1, such as, for example, a tile stove, fireplace stove, pellet stove, solids heating system, solid hot water or the like is provided with a combustion chamber 3 connected to an exhaust duct 2, in which a solid fuel 4 is arranged and burned on a base 5 ( see. Fig. 2 ). In this case, at least part of the air supply to the combustion process takes place through recesses 6 of the base 5. In or at the exhaust duct 2, a filter device 8 equipped with filter material 7 for reducing the fine dust content from the combustion process of the fuel 4 is arranged. The device is further constructed such that the filter material 8 of the filter device 7 in an advanced, at least low-phase (phase IV and / or V) of the combustion process of the fuel 4 in the combustion chamber 3 of the heater 1 can be transferred.

The filter device 7 is arranged adjacent to the combustion chamber 3. This spatial proximity facilitates the displacement of the filter device 7 to the combustion chamber 3. About a Freigabevornchtung 9, the displacement of the filter material 8 can be performed or initiated in the combustion chamber 3. For example, the fuel material 4 is integrally formed or in the form of bulk material, so that the filter material 8 is releasably secured by means of a clamping seat and is released by triggering the release device 9 of the clamping seat; so that the filter material 8 can fall, for example due to gravity into the combustion chamber 3. For example, the release device 9 has a pin which engages in a recess of the filter material 8 and to release the filter material 8, the pin is pulled out of the recess of the filter material 8 (not shown). In the drawing figures 2 and 3, a sensor 10 is disposed within the combustion chamber 3 in addition to the release device 9. This sends signals via the line 11 either directly to the release device (not shown) or indirectly via a central computer 12. The input signals of the example designed as a flue gas sensor, lambda sensor, air flow sensor and / or temperature sensor 10 are compared in the computer 12 and when a defined threshold value is exceeded, which detects either the short-term imminence of phase IV and / or V or the entry of phases IV or V, generates an output signal which is transmitted via line 13 to the release device 9, so that the release device 9 perform the displacement of the filter material 8 in the combustion chamber 3 and / or can initiate. In this case, the release device 9 can be controlled electronically, electrically and / or mechanically. The threshold values can preferably be variable for the operator, so that adaptation to different fuels can be carried out.

It is also possible that the output signal of the sensors 10 in other ways, such as discolorations of a material or output on a screen display (not shown) to signal a user the achievement and / or the short-term imminence of the phases IV and / or V, so this can manually actuate the release device 9.

In the drawing figures 3 and 4, a temporarily switched on and wegschaltbare, so to speak, coupled, bypass line 14 for bypassing the filter device 7 is shown. The bypass line 14 comprises, on the one hand, the line path 15 and a bypass line opening / closing element 16, which in the embodiment shown is in the form of a flap. The opening / closing element 16 is shown in Figure 3 in the closed position - filter device 7 active position and drawing figure 4 in the open position - filter device 7 deactivation position shown Advantageously, the opening / closing element 16 is controlled via a drive device 17. The drive device 17 can in turn be operatively connected to at least one of the sensors 10 and / or the computer 12 (not shown). On the one hand, the filter device 7 can be bypassed via the control of the opening / closing element 16, in particular in the startup phase (phase I) of the heating device 1, whereby the lowest possible resistance for the exhaust gases in the exhaust air duct 2 is achieved. A replenishment of the filter device 7 with filter material 8 can be carried out, for example, via a storage container equipped with filter material 8, which is arranged adjacent to the filter device. This refilling process of the filter material 8 from the storage container into the filter device 7 can preferably also be effected via corresponding conveying or releasing means both manually and by automated means, e.g. B. electrically or electronically via sensors 10 and / or the computer 12 are executed or initiated.

In the drawing figure 5 is an alternative embodiment with at least similar possibilities, as in the heating device 1 according to FIGS. 3 and 4 shown. In this case, the release device 9 consists essentially of two slidably mounted below the filter material 8 sliders 18, 19. The filter material 8 can either be formed in one piece again or, if the filter device 7 has a filter chamber 20 are stored as a powdery material. Regardless of whether it is a powdery, granular and / or one-piece filter material 8, this can on the release device 9 - in this case, the slide 18 - rest. In drawing figure 6a, the bypass position is shown. The exhaust air is transported via the bypass line 14 into the environment. In drawing figure 6b, the slider 19 has been displaced by displacement of the handle 22 in the direction of arrow A and thus closed the bypass line 14, so that the exhaust air must pass through, for example, a sieve-like designed slider 18 and the exhaust air inside the filter material 8 of the filter device 7 undergoes a cleaning , For example, if the phase IV and thus the complete combustion of the fuel 4 takes place, by pressing the handle 21 and thus the displacement of the slider 18 in the direction of arrow A, the filter material 8 by gravity in free fall (arrow B) to the combustion chamber 3 arrive (see FIG. Fig. 6c ).

In drawing figure 6d, the slide 18, 19 are back in the starting position, so that a new start of the heating system can be set in motion and the release of the bypass line 14, the firing of the heating system is facilitated. Through the open flap 23, a new filter material 8 can be inserted into the filter chamber 20 (arrow C). An automatic coating of the filter chamber 20 with filter material 8 from a filter material supply device is an advantageous embodiment.

Another idea is to provide within the combustion chamber 3 a means which favors the combustion of the filter material 8 and the filtrate contained in the filter material 8 in the combustion chamber 3 (not shown).

In particular, in the embodiment according to the drawing figures 5, 6a to 6d, it may be advantageous if at least one of the slides 18, 19 is held biased in the positions shown in drawing figures 5 and 6a. Also for the opening and closing element 16 a bias in the closed position (filter active position) is advantageous.

LIST OF REFERENCE NUMBERS

I to V

phase

A

arrow

B

arrow

C

arrow

1

heater

2

exhaust duct

3

combustion chamber

4

fuel

5

document

6

Recess v. 5

7

filtering device

8th

filter material

9

release device

10

sensor

11

management

12

computer

13

management

14

bypass line

15

pathway

16

Opening / closing member

17

driving

18

pusher

19

pusher

20

filter chamber

21

handle

22

handle

23

flap

Claims (15)

1. Method for reducing the proportion of fine dust in the exhaust air of a heating apparatus that burns solid fuel, in particular of a tile stove or a fireplace stove, a fireplace, a pellet stove, a solid-fuel heating system or the like, wherein the waste gases are guided through a filter material in the exhaust duct or in a combustion chamber of the heating apparatus, wherein the filter material is entirely or partially conjointly combusted in an advanced and at least low-soot phase of the burn-off of the fuel within the heating apparatus, characterized in that the waste gases of the low-soot combustion phase, as from the supply of the filter material into the combustion chamber, make their way through the exhaust duct in a non-filtered manner.
2. Method according to Claim 1, characterized in that the supply of the filter material into the combustion chamber 1 of the heating apparatus is performed automatically.
3. Method according to Claim 2, characterized in that the automatic supply of the filter material into the combustion chamber is performed so as to be radiation-sensor controlled.
4. Method according to one of the preceding claims, characterized in that the waste gases, at least in a first initial combustion phase of the fuel, are guided so as to bypass the filter material.
5. Method according to one of the preceding claims, characterized in that the waste gases, in a first initial combustion phase, are actively suctioned and/or blown through the filter material.
6. Method according to one of the preceding claims, characterized in that the supply of the filter material into the combustion chamber is performed during a burn-off phase in which the fuel burns off in an ember-preserving manner without forming flames.
7. Method according to one of the preceding claims, characterized in that the filter is provided with combustion-active embankments.
8. Heating device (1) for carrying out the method according to one of the preceding claims, in particular a tile stove or a fireplace stove, a fireplace, a pellet stove, a solid-fuel heating system, a solid-fuel water boiler, or the like, having a combustion chamber (3) which is connected to an exhaust duct (2) and in which a solid fuel (4) is combustible, wherein a filter installation (7) that is equipped with filter material (8) for reducing the proportion of fine dust is disposed in or on the exhaust duct (2), and when in operation the filter material (8) of the filter installation (7) in an advanced and at least low-soot phase IV, V of the burn-off process of the fuel (4) is introducible into the combustion chamber (3) of the heating apparatus (1), characterized in that the waste gases of the low-soot combustion phase, as from the supply of the filter material (8) into the combustion chamber (3), make their way through the exhaust duct (2) in a non-filtered manner.
9. Heating device according to Claim 8, characterized in that the filter installation (7) has a filter chamber (20) in which the filter material (8) is disposed, wherein the filter chamber (20) is provided with a release device (9) for releasing the filter material (8) into the combustion chamber (3).
10. Heating device according to Claim 9, characterized in that the filter material (8) bears on the release device (9), and the release device (9), for introducing the filter material (8) into the combustion chamber (3) on account of gravity, folds upwards or is displaceable below the filter material (8).
11. Heating device according to Claim 8, characterized in that a release device (9) carries out and/or initiates the repositioning of the filter material (8) into the combustion chamber (3), wherein the release device (9) holds the filter material (8) in a form-fitting and/or force-fitting manner, the form-fitting and/or force-fitting connection being capable of being cancelled by a release mechanism.
12. Heating device according to Claim 8, characterized in that a release device (9) carries out and/or initiates the repositioning of the filter material (8) into the combustion chamber (3), wherein the release device (9) is operatively connected to at least one waste gas sensor, lambda sensor, air flow rate sensor and/or temperature sensor.
13. Heating device according to Claim 8, characterized in that a release device (9) carries out and/or initiates the repositioning of the filter material (8) into the combustion chamber (3), wherein the release device (9) is operatively connected to a bimetal which activates the release device (9) as from a temperature threshold value.
14. Heating device according to one of Claims 8 to 13, characterized in that a storage container that is equipped with filter material (8) is connected to the filter installation (7) and in a controllable and/or regulatable manner repositions filter material (8) into the filter installation (7).
15. Heating device according to one of Claims 8 to 14, characterized in that a bypass line (14) for circumventing the filter installation (7) is coupleable in a temporary manner.

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