EP2910854A2 - Flue gas valve device - Google Patents

Abstract

The invention relates to a flue gas valve device (1), comprising a flue gas flap (2), a rotatable shaft (3), and a holding device, wherein the flue gas flap (2) is connected to the shaft (3) and wherein the flue gas flap device (1) is designed for this purpose in that the retaining device holds the flue-gas flap (2) in a closed operating position against the force of gravity and that the holding device can release the flue-gas flap (2) so that the flue-gas flap (2) is moved into an open operating position due to gravity.

Description

FIELD OF THE INVENTION

The present invention relates generally to a flue gas flap device as well as to a heater for burning biomass with such a flue gas flap device.

BACKGROUND OF THE INVENTION

Generally, heaters such as e.g. Stoves are known which use biomass as fuel, e.g. (Log) wood, wood chips, pellets and the like. Such heaters usually have at least one firebox that is accessible via a firebox door and through which fuel can be introduced into the firebox.

In case of bad chimney draft, unfavorable weather conditions, which can also lead to an unfavorable chimney draft, long or unfavorable flue gas path in the heater or between heater and chimney and the like flue gas can escape from the combustion chamber, for example, when refilling of fuel, the furnace door is opened ,

To avoid the escape of flue gases when opening a firebox door, it is eg off DE 37 37 661 C2 known to provide a flue damper in the furnace. The flue damper is closed during normal heating and is then opened when the firebox door is opened, providing a bypass for the flue gases from the firebox directly into a chimney. In this way, the flue gases are discharged from the firebox directly into the fireplace and do not get out of the firebox through the open firebox door into the environment to the outside.

From the German patent DE 10 2006 009 760 B3 a Fülltürmechanismus for a heater with a safety device is known, which generates a signal with open or closed filling door at the same time locked arrested flue damper or opens the lock when closing the filling door, so that the flue damper closes automatically. The flue damper is biased by its own weight in the closed position. The known flue gas valve device is complicated and expensive.

The object of the present invention is to provide an improved flue-gas flap device and a heating device with such a flue-gas flap device.

SUMMARY OF THE INVENTION

According to a first aspect, the present invention provides a flue gas flap device comprising: a flue damper, a rotatable shaft, and a holding device, wherein the flue damper is connected to the shaft, and wherein the flue gas flap device is adapted for the holding device to hold the flue damper in one holds closed operating position against gravity and that the holding device can release the flue, so that the flue damper is moved by gravity into an open operating position.

According to a second aspect, the present invention provides a heating device for burning biomass with a combustion chamber and a flue gas valve device according to the first aspect.

Further aspects and features of the present invention will become apparent from the dependent claims, the accompanying drawings and the following description of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING

• Fig. 1 ein Ausführungsbeispiel einer Rauchgasklappeneinrichtung veranschaulicht;
• Fig. 2a die Rauchgasklappe der Rauchgasklappeneinrichtung von Fig. 1 in einer geschlossenen Betriebsstellung zeigt;
• Fig. 2b die Rauchgasklappe der Rauchgasklappeneinrichtung von Fig. 1 in einer offenen Betriebsstellung zeigt;
• Fig. 3 die Rauchgasklappe mit einem Filtereinsatz veranschaulicht;
• Fig. 4 schematisch eine Heizeinrichtung mit der Rauchgasklappeneinrichtung von Fig. 1 illustriert; und
• Fig. 5 eine Steuerung zum Steuern der Rauchgasklappeneinrichtung von Fig. 1 zeigt.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

• Fig. 1 an embodiment of a flue gas flap device illustrated;
• Fig. 2a the flue damper of the flue gas valve device of Fig. 1 in a closed operating position;
• Fig. 2b the flue damper of the flue gas valve device of Fig. 1 in an open operating position;
• Fig. 3 illustrates the flue damper with a filter cartridge;
• Fig. 4 schematically a heater with the flue gas valve device of Fig. 1 illustrated; and
• Fig. 5 a controller for controlling the flue gas valve device of Fig. 1 shows.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the Fig. 1 to 3 An embodiment of a flue gas flap device 1 according to the present invention is illustrated. Before a detailed description follows first general explanations to the embodiments.

As stated above, there is a risk that when opening a furnace door of a combustion chamber of a heater flue gas can pass through the open firebox door to the outside.

In addition, excessive flue gas evolution can also occur during firing, when flue gases occur in a cold chimney, a small flue draft, higher pressure drop due to a filter or catalyst insert through which the flue gas flows from the furnace, and the like. The excessive generation of smoke can be found especially in the operation of the heater with a particulate matter filter e.g. a filter / catalyst have a negative effect, since the catalytic effect of a filter / catalyst begins only at a high temperature level and the openings of the filter / catalyst at a lower temperature soot much faster.

Accordingly, the embodiments relate to a flue gas valve device which comprises a flue gas flap, a rotatable shaft and a holding device. The flue damper is connected to the shaft. The flue gas flap device is designed so that the holding device holds the flue damper in a closed operating position against gravity and that the holding device can release the flue gas flap, so that the flue gas flap is moved by gravity into an open operating position.

When the holding device is triggered, therefore, the flue gas flap falls due to its own weight from the closed operating position to the open operating position, wherein it rotates together with the rotatable shaft about the axis of rotation of the rotatable shaft. In addition, the flue damper can be biased by a spring which controls the movement from the closed operating position to the open operating position supports and, for example, also overcomes any sticking of the flap in the closed operating position due to soot formation in the combustion chamber.

The flue gas flap may be connected with its longitudinal side with the rotatable shaft, but it may also be connected at one of its flat sides with the rotatable shaft.

In some embodiments, the flue gas flap is moved from the open to the closed operating position (exclusively) mechanically and / or manually, for example by means of a crank or a lever.

The flue gas flap device can, as has been explained at the beginning, e.g. be provided in a heater for burning biomass as solid fuel, such as (log) wood, wood chips, pellets or the like. It can open or close a bypass, are derived by the flue gases directly into a fireplace to which the heater is connected.

Thus, for example, a flue gas outlet can be avoided or at least reduced during a Brennstoffnachfüllgangs with open firebox door.

The fact that the flue gas flap falls by its own weight or by acting on them gravity from the closed operating position to the open operating position, a quick and easy opening of the flue damper is possible and there is no separate mechanism required, the flue gas door active from the closed in conveys the open operating position, as is the case for example in the above-mentioned prior art.

The holding device can be designed mechanically and / or electrically releasable to release the flue gas flap. The triggering of the holding device can also be coupled with the opening of a furnace door of the heater.

When configured for electrical release, the holding device may include an electromagnet, such as an electromagnet. The electromagnet generates a magnetic field during operation which is designed to hold the flue damper in the closed operating position. For this purpose, the flue damper may have a metallic or magnetic portion which in Contact with the electromagnet is stopped when the flue damper is in the closed operating position. Is or is the electromagnet de-energized, so the holding device releases the flue damper so that it falls by itself from the closed operating position to the open operating position. As a result, even in the event of a power failure, reliable burn-off in a heating device is ensured, since in the open operating position the flue-gas outlet is markedly improved.

If the holding device is designed for the mechanical release, then it can have a spring-biased lock. The flue damper can then be configured accordingly to engage in the spring-biased latch, for example by means of a hook or bolt, in the closed operating position. By actuating the lock, the holding device can release the flue gas flap by releasing the hook, the bolt or the like.

In some embodiments, the flue gas flap device further comprises a drive configured to move the flue gas flap from the open operating position to the closed operating position. The drive can be designed mechanically and, for example, be actuated by a lever or a crank or the like. The drive can also be designed to be electrically operable and, for example. comprise an electric motor.

The drive can be coupled via a mechanical coupling with the rotatable shaft. The drive itself may have a drive shaft so that the mechanical coupling couples the drive shaft and the rotatable shaft together. As a result, the drive or the drive shaft is not rigidly coupled to the rotatable shaft in some embodiments.

The mechanical coupling may be configured to decouple the drive from the rotatable shaft when the flue damper is in the closed operating position. As a result, the drive can be moved back to a starting position so that it is ready for use again. In addition, the flue damper can be moved back from its open operating position to its closed operating position.

The drive may in some embodiments be designed to be rotatable only in one direction and thus drive the rotatable shaft in one direction only. The mechanical coupling is then designed such that it as long as the Drive with the rotatable shaft coupled until the flue damper is moved from its open operating position to the closed operating position. Then, the mechanical coupling decouples the rotatable shaft from the drive or from its drive shaft and the drive can be further rotated in its fixed direction until it is back in its starting position, in which the mechanical coupling again the drive or its drive shaft with the rotatable Wave couples.

The drive may also be designed in other embodiments to be rotatable in two directions. When the flue damper is moved from the open operating position to the closed operating position, the drive or a controller operating the drive detects that the flue damper is in the closed operating position and stops the drive. Thereafter, the drive is moved back to its initial position in which he is able to move the flue damper back from the open to the closed operating position. Again, the mechanical coupling can decouple the drive or its drive shaft of the rotatable shaft until the drive is back in the starting position.

Once the flue damper is in the closed operating position, the retainer retains it, as described above, e.g. the solenoid is operated, a hook, bolts or the like engages in the spring-biased lock or another locking means that holds the flue damper.

In some embodiments, the flue gas flap device includes a controller configured to control the drive after a predetermined period of time to move the flue damper from the open operating position to the closed operating position.

The controller may include a microprocessor configured to perform the steps described herein and a volatile and / or read-only memory for storing data, such as the predetermined amount of time.

Due to the fact that the control activates the drive after the predetermined period of time to move the flue-gas flap from the open operating position into the closed operating position, it can not be forgotten to close the flue-gas flap again.

The flue damper can also be driven by a drive designed as a servomotor with a return member, e.g. can be biased by a spring or hydraulically and, for example, can be configured as a spring return. There are two end positions, namely an open, in which the flue damper in an open operating position, and a closed, in which the flue damper is in a closed operating position and in which the return member is biased accordingly. When the flue damper is closed and the power fails, the flue gas damper is then opened by the restoring member (spring return mechanism) or by the force exerted due to the prestressing force. In some embodiments, the return member and / or the servomotor is correspondingly configured such that it can bring the flue damper in the open position, even if the actuator is not decoupled, i. the return member turns the flue damper together with the non-mechanical decoupled actuator in the open operating position.

The flue gas flap can have a filter insert which is set up to filter pollutants from flue gas flowing through it and / or to catalytically oxidize it. Flue gas flows through the filter element when the flue damper is in the closed operating position, but not in the open operating position.

This makes it possible, e.g. to leave the flue damper in an open operating position until, for example, flue gas to flow through the filter cartridge has reached a predetermined temperature. The predetermined temperature may correspond to an operating temperature of a catalyst material in the filter cartridge. Accordingly, it is possible to move the flue gas flap into the closed operating position only when the flue gas has reached the predetermined temperature and so pollutants or combustion residues in the flue gas can be oxidized by the catalyst material. For temperature measurement, a temperature sensor may be provided which determines the flue gas temperature and transmits, for example, to the control described above, which controls the electric drive when a predetermined temperature threshold value is exceeded and moves the flue gas flap into the closed operating position.

In some embodiments, an operating element is further provided, which is designed such that by releasing the operating element, the holding device releases the flue gas flap. The control element may be mechanically and / or electrically formed and mechanically and / or electrically cause the Holding device releases the flue gas flap. For example, the control element may be designed as a lever or the like and mechanically coupled to the holding device, so that a mechanical actuation of the operating element actuates the holding device accordingly. The control element can also be designed as an electrical switch, which generates an electrical signal when actuated, which is transmitted to the holding device and / or to a controller and causes the holding device accordingly to release the flue gas flap.

In some embodiments, the flue damper is biased in the closed operating position, for example by a spring or hydraulically, to assist movement to the open operating position. For example, should the flue damper stick during operation due to soiling or the like and not open by gravity alone, the flue damper can be released by the force exerted by the biasing force.

Some embodiments relate to a heating device for burning biomass with a combustion chamber and a flue gas flap device, as described above. The heater may be configured as a log wood stove, stove, pellet stove, wood boiler, or the like. The heater is configured for the burning of solid fuel, wherein the fuel, as stated above, consists of biomass. The heater has a firebox door through which the firebox is filled with solid fuel and / or through which the firebox is cleaned. In some embodiments, the heater also has an automatic fuel supply and the firebox door is opened, for example, only for cleaning for the maintenance and / or lighting of fuel.

The heating device, the flue-gas flap device or the holding device can be set up to release the flue-gas flap in the closed operating position when a furnace door of the firebox is opened. This can be carried out mechanically and / or electrically. For example, a control element configured as a lever or the like can be actuated by opening the firebox door, which in turn actuates the holding device and releases the flue-gas flap. It can also be provided a switch which generates a signal when opening the firebox door and transmitted to the control described above, which in turn operates the holding device so that it releases the flue by, for example, the current electromagnets switched off. In embodiments at where an operating element is provided, the signal can also be generated by operating the operating element.

Coming back to the Fig. 1 to 3 an embodiment of a flue gas flap device 1 is shown there.

The flue gas flap device 1 has a flue gas flap 2, which is connected to a rotatable shaft 3. The rotatable shaft 3 is mounted on two bearing blocks 4a and 4b. In addition, the rotatable shaft 3 is coupled via a mechanical coupling 6 to a drive shaft 5 of an electrically operable drive 7. The drive 7 has an electric motor which is coupled to the drive shaft 5 and drives them.

The flue gas flap 2 can be a closed operating position, the in Fig. 2a is illustrated, and an open operating position, in Fig. 2b is illustrated, take.

In order to hold the flue-gas flap 2 in the closed operating position, the flue-gas flap device 1 has a holding device 8 which is designed as an electro-adhesive magnet and is arranged above the flue-gas flap 2 in the closed operating position. The holding device 8 generates a magnetic field and thereby holds the flue gas flap 2 in the closed operating position. In the closed operating position, the flue gas flap 2 extends horizontally in the present embodiment, while in other embodiments, it can also extend at an angle to the earth's surface. However, in the closed operating position, the flue gas flap 2 does not run perpendicular to the earth's surface, since otherwise it can not be moved by gravity into the open operating position.

The flue gas flap 2 is metallic and magnetic at least in the area in which the holding device 8 holds the flue gas flap 2 in the closed operating position.

If the holding device 8 releases the flue gas flap 2 by switching the electromagnet magnetless, the flue gas flap 2 by its own weight and gravity acting on it can fall down, being due to the connection with the rotatable shaft 3, a rotational movement about the longitudinal axis or Rotary axis of the rotatable shaft 3 executes, the rotational movement of the in the Fig. 2a and 2b illustrated flue gas flap 2 is a clockwise movement. This way the flue gas flap 2 in an open operating position, which leads in the embodiment illustrated here to a vertical position of the flue gas flap 2. In other embodiments, the flue damper 2 may also be in an open operating position with the flue damper 2 not in the vertical position.

The mechanical coupling 6 is here designed such that it decouples the rotatable shaft 3 from the drive shaft 5 of the drive 7 when the flue gas flap 2 is in the closed operating position and is held by the holding device 8. Accordingly, the rotatable shaft 3 is freely rotatable, so that the flue gas flap 2 can rotate freely from the closed operating position to the open operating position by rotation of the rotatable shaft 3 when released from the holding device 8.

In order to move the flue gas flap 2 from the open operating position back to the closed operating position, the drive 7 drives the drive shaft 5, the mechanical coupling 6 coupling the drive shaft 5 to the rotatable shaft 3. This allows the drive 7, the rotatable shaft 3 and thus the flue gas flap 2 - turn counterclockwise here - back to the closed operating position. As soon as the flue-gas flap 2 has reached the closed operating position, the holding device 8 is operated by supplying the electromagnetic-pressure magnet so that it retains the flue-gas flap 2. The mechanical coupling 6 decoupled in this position, the drive shaft 5 of the rotatable shaft 3. The drive 7 then rotates the drive shaft 5 in the starting position by turning the drive shaft 5 in the opposite direction back to the starting position. The flue gas flap 2 can thus be released again by the holding device 8 and move from the closed operating position to the open operating position. When re-closing the flue gas flap, the drive shaft 5 is again coupled to the rotatable shaft 3 through the mechanical coupling 6.

Fig. 3 shows an embodiment, according to which the flue gas flap 2 has a filter cartridge 2a, which is held by a filter enclosure 2b. The filter element 2a is provided here with a catalytic material which oxidizes combustion residues from a predetermined operating temperature and thus supports their combustion.

An embodiment of a heater 20, which is exemplified here as a log stove, has a housing 21 in which a combustion chamber 22 is arranged, as it Fig. 4 purely schematically illustrated.

Above the firebox 22, the flue gas flap device 1 is arranged such that the flue gas flap 2 with integrated filter insert 2a sits in front of a flue port 23 designed as a stovepipe, so that flue gas which arises during the combustion of firewood in the firebox 22 flows through the filter element 2a when the flue gas flows Flue gas flap 2 in the in Fig. 4 shown closed operating position.

The flue gas flap 2 can be brought from the closed operating position to the open operating position, as in Fig. 2b is illustrated, when the holding device 8, which is arranged above the flue gas flap 2, the flue gas flap 2 releases. The filter element 2a is no longer traversed by flue gas when the flue gas flap 2 is in the open operating position.

Of course, the flue door may be located elsewhere in other heaters and / or for a different purpose. For example, in a heater having a heat exchanger through which the flue gas is passed in normal operation, a bypass may be provided through which the flue gas is passed around the heat exchanger. The flue-gas flap device or the flue-gas flap of the flue-gas flap device can be arranged in front of such a bypass, with the flue-gas flap then having no filter insert. When a firebox door is opened or e.g. during a combustion phase of the fuel then the flue gas flap can be opened to pass the flue gas past the heat exchanger through the bypass into the chimney.

An operation of the flue gas flap device 1 by an associated controller 25, which may be part of the flue gas flap device 1 and / or the heater 20 will now be in connection with the Fig. 5 explained. The controller 25 has a microprocessor and a memory in which operating parameters are stored.

The controller 25 is coupled to the drive 7, the holding device 8, an operating element 26, a door switch 27 and a temperature sensor 28.

The temperature sensor 28 determines a flue gas temperature of the flue gas, the flows through the filter element 2a of the flue gas flap 2 and transmits the flue gas temperature to the controller 25. The temperature sensor 28 is, for example, arranged in the vicinity of the flue gas flap 2 in the chimney port 23.

The operating element 26 is designed as an actuating button and it sends a corresponding actuating signal to the controller 25 when it is actuated by a user.

The opening can also be done by the door switch 27 by a corresponding opening signal is transmitted to the controller 25 when the firebox door of the firebox 22 is opened.

In the normal operating state, the flue gas flap 2 is in the closed operating state, so that flue gas would flow through the filter insert 2 a. Accordingly, the controller 25 controls the holding device 8, so that the holding device 8 holds the flue gas door 2 in the closed operating position by supplying power to the electro-adhesion magnet.

Receives the controller 25, the actuation signal of the control element 26, it controls the holding device 8 to release the flue gas flap 2 by the electromagnet magnet is de-energized.

After a predetermined period of time, for example 60 seconds, the controller 25 controls the drive 7 so that it moves the flue gas flap 2 back into the closed operating state and it controls the holding device 8 to hold the flue gas flap 2 again in the closed operating state. The closed position of the flue gas flap 2 is detected here by a proximity switch 29 (see FIG. 5 ).

In addition, the controller 25 has stored in its memory a predetermined temperature threshold and it compares the temperature values received from the temperature sensor 28 with the temperature threshold. The temperature threshold characterizes an operating temperature from which the catalyst material of the filter insert 2a can oxidize combustion residues. Accordingly, the controller 25 leaves the flue gas door 2 in the open operating position until the received temperature value exceeds the temperature threshold. As soon as the controller 25 determines that the temperature value exceeds the temperature threshold, it controls the drive 7 and the holding device 8 such that the flue gas flap 2 goes into the closed operating state and is held there. If the received temperature value drops below the temperature threshold value, the controller 25 controls the holding device 8 to release the flue gas flap 2 so that it moves into the open operating position.

Receives the controller 25 an opening signal from the door switch 27, it controls the holding device 8 to release the flue door 2, so that it moves to the open operating position. The door switch 27 is here designed so that it transmits the opening signal to the controller 25 until the furnace door is closed again. If the controller 25 determines that it no longer receives an opening signal, it controls the drive 7 and the holding device 8 to move the flue damper 2 back to the closed operating position and to hold it there.

In an alternative embodiment, the door switch 27 sends only a short opening signal when opening the firebox door. In this case, the controller 25 controls after a predetermined period of time, e.g. 60 seconds, the drive 7 and the holding device 8, to move the flue gas flap 2 back to the closed operating position and to hold there. The period of time can be chosen so that after its expiration a typical filling of the combustion chamber 22 is completed with fuel.

The controller 25 is also configured to detect when the flue gas door 2 is in the closed mode. This is done in the present embodiment by a proximity switch 29 which is integrated in the holding device 8. The proximity switch 29 is triggered and transmits a corresponding signal to the controller 25 when the flue gas flap 2 abuts against the proximity switch 29 of the holding device 8. Alternatively, the drive 7 may have a resistance sensor, which detects the increased resistance on the drive shaft 5 when the flue gas flap abuts against the holding device 8. In that case, the drive 7 may either send a signal to the controller 25 which, in response, will drive the drive 7 to return to its home position, or the drive 7 will automatically return to its home position.

If the controller 25 or the holding device 8 is de-energized, eg due to a power failure, the holding device 8 releases the flue gas flap 2 automatically, since the electro-adhesive magnet is no longer supplied with power.

As a result, even in the event of a power failure, safe burning is ensured and, for example, Overheating of a heat exchanger in a heater can be avoided if automatically by opening the flue gas flap, the flue gases are passed through the bypass into the chimney and not through the heat exchanger.

Claims (13)

Flue gas flap device for a heating device for burning biomass, comprising: a flue gas flap (2), a rotatable shaft (3), and a holding device (8), wherein the flue-gas flap (2) is connected to the shaft (3), and wherein the flue-gas flap device is designed such that the holding device (8) holds the flue-gas flap (2) against gravity in a closed operating position and the holding device (8) holds the flue-gas flap (2) can release, so that the flue damper (2) is moved by gravity into an open operating position. Flue gas valve device according to claim 1, further comprising a, in particular electrically operable, drive (7) which is adapted to move the flue gas flap (2) from the open operating position to the closed operating position. Flue gas flap device according to claim 2, wherein the drive (7) via a mechanical coupling (6) with the rotatable shaft (3) is coupled. A flue gas door device according to any one of claims 2 or 3, further comprising a return member biased in the closed operating position and adapted to move the flue gas flap (2) from the closed operating position to the open operating position. A flue gas valve device according to claim 3 or 4, wherein the mechanical coupling (6) is adapted to decouple the drive (7) from the rotatable shaft (3) when the flue gas flap (2) is in the closed operating position. Flue gas flap device according to one of claims 2 to 5, further comprising a controller (25) which is adapted after a predetermined period of time to control the drive (7) such that it the flue gas flap (2) from the open operating position to the closed operating position emotional. Flue gas flap device according to one of the preceding claims, wherein the flue gas flap (2) has a filter insert (2a), which is traversed by flue gas when the flue gas flap is in the closed operating position, and which is not traversed by flue gas when the flue damper in the open Operating position is. Flue gas flap device according to one of the preceding claims, wherein the holding device (8) comprises an electromagnet. Flue gas flap device according to one of the preceding claims, wherein the holding device (8) has a spring-biased locking. Flue gas valve device according to one of the preceding claims, further comprising an operating element (26) which is designed such that by actuation of the operating element (26) the holding device (8) releases the flue gas flap (2). A flue gas flap assembly according to any one of the preceding claims, wherein the flue gas flap (2) is biased in the closed operating position to assist movement to the open operating position. Heating device for burning biomass with a combustion chamber (22) and a flue gas valve device (1) according to one of the preceding claims. Heating device according to claim 12, wherein the holding device (8) releases the flue gas flap (2) in the closed operating position when a firebox door of the firebox (22) is opened.

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