EP3296642B1 - Open fireplace with an air supply device - Google Patents

Description

Background of the invention

The invention relates to an open fireplace in the form of a permanently open fireplace for installation in an installation room with a smoke extractor hood for discharging flue gas from the open fireplace, the smoke extractor hood being located over a furnace which has at least one at least temporarily open, first side through which Fresh air from the installation room can flow into the combustion chamber.

Open fires according to the invention are commonly known as "always open fireplaces". An essential feature of these open hearths is that the fire burning there in a firebox is visible to a user of the open hearth. This display of the fire is possible in that the open hearth has at least one open side on which there is no combustion chamber wall and which can at best be closed by means of a spark grid.

The problem with such open hearths is that air is constantly withdrawn from the room in which the open hearth is set up through the open side of the hearth. This air is to be continuously supplied in accordance with the installation room. Without a supply of air into the installation room, a negative pressure would arise in the installation room, which would prevent the flow of flue gas in the Would bring the smoke extractor hood to a standstill. The negative pressure could also lead to smoke gas escaping from the combustion chamber into the installation room. However, the supply of air into the installation room is not entirely unproblematic, because it can easily lead to air currents in the installation room which are perceived as unpleasant for a user of the open fireplace.

Out EP 0480870 A1 a method for operating a fireplace is known in which combustion air is supplied to a combustion chamber, the combustion chamber being surrounded by side walls and a movable disc delimiting the combustion chamber DE 26 32 056 A1 refer to.

Underlying task

The invention is based on the object of creating an open fireplace in which it is ensured that air is fed into the room where the open fireplace is located in a manner that is comfortable and safe for the user.

Solution according to the invention

This object is achieved according to the invention with an open hearth according to claim 1.

According to the invention, in the case of an open hearth, a narrow slot is formed on that lower edge of the smoke extractor hood, which slit runs along the open side of its combustion chamber. This slot belongs to an air supply device, by means of which fresh air can be fed into this installation room from outside the room where the fireplace is installed.

According to the invention, through the slot of this type, air is directed in a targeted manner to the fireplace where this air can be used to create a pressure equalization in the installation room in a particularly advantageous manner. At the same time, the air is supplied in such a way that air currents in the installation room that are not disruptive for a user of the fireplace result.
According to the invention, the air fed in from the outside into the installation room is also fed to an area at the fireplace where, on the one hand, there is a particularly high risk of smoke gases escaping into the installation room. This is because smoke gases that are created in the combustion chamber by the fire burning in it collect below the smoke extractor hood. Such smoke gases should, according to the purpose of the smoke extractor hood, be discharged from the furnace through the smoke extractor hood to the top of the installation room. At the same time, however, there is a risk that flue gases will not flow out upwards, but rather emerge to the side through the open side of the combustion chamber. This risk is greatly reduced by the locally targeted supply of air according to the invention to the smoke gas hood, in that this air supply in the area of the upper edge of the open side generates a countercurrent to a possible escape of smoke gas into the installation room.

In addition, with the solution according to the invention, the air supplied in this way can be preheated particularly advantageously on the smoke extractor hood, which will be explained further below.

Finally, with such an air supply device, the function of supplying air into the installation room is integrated into the fireplace according to the invention and in particular its smoke extractor hood. No other functional components are therefore necessary for the function of supplying air to the installation room. Overall, in this way the overall expenditure for the construction and operation of the fireplace according to the invention can even be reduced.

According to the invention, it is ensured in this way that on the one hand air flows into the installation room of the open fireplace in a manner that is comfortable for a user and on the other hand no smoke gas can flow out into the installation room.

Advantageous further developments of the invention

In an advantageous development of the invention, the first slot has a constant width along the first side. The slot formed in this way along its length with the same slot width allows the air supplied to flow out evenly distributed along the upper edge of the open side. The amount of air supplied can be influenced by the intended width of the slot. In the fireplace according to the invention, the slot is preferably designed with a width or slot width of between 0.5 cm and 5 cm, particularly preferably with a width of between 1 cm and 3 cm.

The combustion chamber preferably also has an open, second side and the air supply device is designed on the smoke extractor hood along the second side of the combustion chamber with a second slot for supplying air. In this way, a uniform supply of air along the lower edge of the smoke extractor hood or along the upper edge of the open sides is created along the entire open part of the combustion chamber.

In the same way, the combustion chamber according to the invention advantageously has an open, third side and the air supply device on the smoke extractor hood is also designed along the third side of the combustion chamber with a third slot for supplying air.

The air supply device according to the invention is also preferably designed with a first air guide section, by means of which the air to be supplied is guided along the smoke extractor hood when the open fireplace is in operation. The air guided along the smoke extractor hood in this way is preheated by the direct contact of the then warm or hot smoke extractor hood before it is released through the slot according to the invention. In particular, the preheated air reduces a possible temperature gradient between the air supplied and the air present in the installation room. In this way, temperature-related air turbulence in the installation room can also be avoided. In addition, the smoke extractor hood can be cooled at the same time.

The combustion chamber of the open hearth according to the invention advantageously also has at least one closed side and the air supply device is designed with a second air guide section by means of which the air is directed along the at least one closed side. The at least one closed side is usually a rear wall of the combustion chamber. This rear wall is then likewise cooled with the air supply device according to the invention and at the same time the supplied air is preheated.

The air supply device according to the invention is preferably provided with a first air inlet on the at least one closed side. In this area of the open hearth, an external air supply duct can advantageously be coupled to the air inlet. The first air inlet can have a particularly large air inlet opening. This is particularly advantageous in order to keep the flow resistance of the air supply device according to the invention as low as possible overall.

The combustion chamber is preferably also designed with at least one floor surface and the air supply device has a third air guiding section with which the air is guided along the floor surface. Such a floor area then on the one hand also contributes to the preheating of the supplied air and on the other hand is cooled at the same time.

The air supply device is also advantageously provided with a second air inlet on the floor surface. The air inlet of this type is also easily accessible for an external air supply duct and can be of large dimensions.

The first or second air inlet is advantageously designed to be optionally closable with a blind cover. In this way, an air supply duct can be routed from the outside as an alternative to the first or second air inlet without any noteworthy adaptations or changes being necessary to the open hearth according to the invention. In this case, at most, only the blind cover has to be moved from one air inlet to the other air inlet.

Brief description of the drawings

Fig. 1

eine Vorderansicht eines ersten Ausführungsbeispiels einer erfindungsgemäßen offenen Feuerstelle,

Fig. 2

den Schnitt II - II gemäß Fig. 1,

Fig. 3

den Schnitt III - III gemäß Fig. 2,

Fig. 4

den Schnitt IV - IV gemäß Fig. 1,

Fig. 5

eine Vorderansicht eines zweiten Ausführungsbeispiels einer erfindungsgemäßen offenen Feuerstelle,

Fig. 6

den Schnitt VI - VI gemäß Fig. 5,

Fig. 7

den Schnitt VII - VII gemäß Fig. 6 und

Fig. 8

den Schnitt VIII - VIII gemäß Fig. 5.

In the following, exemplary embodiments of the solution according to the invention are explained in more detail with reference to the accompanying schematic drawings. It shows:

Fig. 1

a front view of a first embodiment of an open hearth according to the invention,

Fig. 2

the section II - II according to Fig. 1 ,

Fig. 3

the section III - III according to Fig. 2 ,

Fig. 4

the section IV - IV according to Fig. 1 ,

Fig. 5

a front view of a second embodiment of an open hearth according to the invention,

Fig. 6

the section VI - VI according to Fig. 5 ,

Fig. 7

the section VII - VII according to Fig. 6 and

Fig. 8

the section VIII - VIII according to Fig. 5 .

Detailed description of the exemplary embodiments

In the Figs. 1 to 4 an open hearth 10 is shown which is provided with a furnace 12 for receiving a fire (not shown) burning there. The essentially cuboid combustion chamber 12 has in relation to the Fig. 1 a rear wall or closed side 14, as well as a front or open first side 16, a right side or open second side 18 and a left side or open third side 20. Furthermore, the combustion chamber 12 is delimited at the bottom by a floor area 22.

A lifting device 24 is located above the combustion chamber 12, by means of which a spark grid arrangement 26 can be raised and lowered. In the lowered state, the spark grid arrangement 26 is then located on the otherwise open first, second or third side 16, 18, 20. The combustion chamber 12 of this type can therefore be optionally opened by means of the lifting device 24 and the associated spark grid arrangement 26 located on three sides and to lock. A fire burning in the combustion chamber 12 can be seen in particular when the spark grid arrangement 26 is raised. Associated spark grids of the spark grid arrangement 26 are, however, generally designed to be transparent in such a way that the fire is visible even when the spark grid arrangement 26 is closed or lowered. Furthermore, even in the lowered state, air from the installation space of the open fireplace 10 can flow through the open sides 16, 18, 20 into the combustion chamber 12 through the spark grid.

To divert smoke gases from the fire burning in this way in the furnace 12, a smoke extractor hood 28 is arranged above the furnace 12. The smoke extraction hood 28 encloses a smoke extraction space which, starting from the combustion chamber 12, tapers upwards in the shape of a funnel to form a smoke extraction pipe 32.

A substantially horizontally arranged, plate-shaped and largely flat weir surface 34 is arranged between the combustion chamber 12 and the smoke extraction chamber 30. The weir surface 34 thus forms a ceiling surface for the combustion chamber 12. The weir surface 34 is designed at its edges in such a way that it extends at the rear to the rear wall or closed side 14. On the front side or open first side 16, the weir surface 34 leaves a first gap 36 between the combustion chamber 12 and the smoke extraction chamber 30 open. Likewise, the weir surface 34 leaves a second gap 38 and a third gap 40 open along the right-hand side or open second side 18 and along the left-hand side or open third side 20 between the combustion chamber 12 and the smoke extraction chamber 30. The weir surface 34 thus prevents, on the one hand, in the center and also on the back of the combustion chamber 12, smoke gases from rising from the combustion chamber 12 into the smoke extraction chamber 30.On the other hand, the weir surface 34 guides the rising smoke gases to the open sides 16, 18, 20 of the combustion chamber 12 and then conducts the flue gases there from the combustion chamber 12 upwards into the smoke extraction chamber 30.

When the flue gases are diverted in this way, there is a greater negative pressure at the gaps 36, 38 and 40 compared to an open top surface of the combustion chamber 12 and thus increased suction for the flue gases flowing into the smoke extractor hood 28 there. This increased suction sucks in fresh air from the installation room of the open hearth 10 on the open sides 16, 18, 20 into the gaps 36, 38 and 40. In this way, it is reliably prevented that flue gas can escape from the combustion chamber into the installation room.

The weir surface 34 is preferably located between 3 cm and 10 cm, in particular between 5 cm and 8 cm above the lower edge 42 delimiting the smoke extractor hood 28 at the open sides 16, 18, 20 at the bottom.

The first gap 36 has a constant width of 6 cm along the first side 16. The second gap 38 tapers from the closed side 14 towards the first side 16 from a width of 14 cm to a width of 2 cm. Likewise, the third gap 40 tapers from the closed side 14 towards the first side 16 from a width of 14 cm to a width of 2 cm.

In the Figures 5 to 8 an embodiment of an open hearth 10 is illustrated, which has a left side wall or closed, third side 44 instead of an open, third side. Furthermore, in this open hearth 10 according to Figures 5 to 8 the first gap 36, starting from this closed third side 44, tapers along the first side 16. The first gap 36 has a width of 12 cm near the third side 44 and a width of 4 cm near the second side 18.

In Fig. 6 Finally, a closure device 46 which is arranged essentially in the smoke extraction space 30 and by means of which the smoke extraction hood 28 can be optionally closed can also be seen. The closure device 46 is to be operated from below the weir surface 34, it being possible for this to have a recess (not shown) for this purpose.

The lifting device 24 is designed with an air supply hood 48 on the outside. This air supply hood 48 is in the plan view (see Fig. 4 and 8th ) U-shaped around the smoke extractor hood 28 around, double-walled and designed cup-shaped open at the bottom (see Figs. 2 and 3 as well as 6 and 7). Within the cup shape, the air supply hood 48 encloses the spark grid arrangement 26 laterally and at the top. The spark grid can be extended or lowered downwards from the air supply hood 48 and moved upwards into the air supply hood 48 or raised.

The air supply hood 48 has on its underside or lower edge, which is also the lower edge 42 of the smoke extractor hood 28, a first slot 50, a second slot 52 and a third slot 54. The first slot 50 extends along the open, first side 16, the second slot 52 extends along the open, second side 18, and the third slot 54 extends along the open, third side 20.

The smoke extractor hood 28 is enclosed on the outside in its lower area by a hollow, first air supply section 56. Furthermore, the rear wall or closed side 14 has a hollow, second air supply section 58 on its side facing away from the combustion chamber 12. A hollow area is also located on the side of the floor surface 22 facing away from the combustion chamber 12, namely a third air supply section 60. second air inlet 64 into it. The air inlets 62 and 64 are circular in terms of their air inlet area with a diameter of between 20 cm and 30 cm, in particular 25 cm, and can optionally be closed largely fluid-tight with a blind cover 66.

The components 48, 50, 52, 54, 56, 58, 60, 62, 64 and 66 of this type together form an air supply device 68, by means of which air can be supplied to the open fireplace 10 from outside an installation room. The supplied air is directed along the bottom surface 22, the rear wall or closed side 14 and along the smoke extraction hood 28, whereby the air is preheated.

The supplied and preheated air then flows out at the slots 50, 52 and 54. The air flowing out in this way thus reaches the installation room of the open fireplace 10 where air from the installation room is also sucked into the smoke extractor hood 28. The air outlet is therefore also in the immediate vicinity of the gaps 36, 38 and 40.

In conclusion, it should be noted that all features that are mentioned in the application documents and in particular in the dependent claims, despite the formal reference made to one or more specific claims, should also be given independent protection individually or in any combination.

List of reference symbols

10

open fireplace

12th

Firebox

14th

closed side or rear wall

16

open, first page or front

18th

open, second side or right side

20th

open, third side or left side

22nd

Floor area

24

Lifting device

26th

Spark grid arrangement

28

Smoke extractor hood

30th

Smoke vent

32

Smoke exhaust pipe

34

Weir area

36

first gap

38

second gap

40

third gap

42

Lower edge

44

closed, third side or left side wall

46

Locking device

48

Air intake hood

50

first slot

52

second slot

54

third slot

56

first air supply section

58

second air supply section

60

third air supply section

62

first air inlet

64

second air inlet

66

Blind cover

68

Air supply device

Claims (10)

1. Open fireplace (10) in the form of a permanently open fire for arrangement in an installation location having a flue gas outlet hood (28) for discharging flue gas of the open fireplace (10), wherein the flue gas outlet hood (28) is located above a fire chamber (12) which has at least one open, first side (16) through which fresh air can flow from the installation location into the fire chamber (12), wherein there is provided an air supply device (68) which is configured on the smoke exhaust hood (28) along the first side (16) of the fire chamber (12) with a first slot (50) for supplying air, characterised in that the smoke exhaust hood (28) is provided with a barrier surface (34) by means of which the fire chamber (12) is delimited at the top and by means of which a first gap (36) is freed along the open, first side (16) of the fire chamber (12) for conducting the flue gas out of the fire chamber (12) into the flue gas outlet hood (28), such that the outflowing air, which is then preheated, at the first slot (50) passes into the installation location of the open fire place (10) directly where air is also drawn from the installation location through the first gap (36) into the flue gas outlet hood (28).
2. Open fireplace according to claim 1,
   characterised in that the first slot (50) along the first side (16) has a constant width.
3. Open fireplace according to claim 1 or 2,
   characterised in that the fire chamber (12) has an open, second side (18) and the air supply device (68) on the flue gas outlet hood (28) is configured along the second side (18) of the fire chamber (12) with a second slot (52) for supplying air.
4. Open fireplace according to claim 3,
   characterised in that the fire chamber (12) has an open, third side (20) and the air supply device (68) on the flue gas outlet hood (28) is configured along the third side (20) of the fire chamber (12) with a third slot (60) for supplying air.
5. Open fireplace according to any one of claims 1 to 4,
   characterised in that the air supply device (68) has a first air-guiding portion (56) with which the air is conducted along the flue gas outlet hood (28).
6. Open fireplace according to any one of claims 1 to 5,
   characterised in that the fire chamber (12) has at least one closed side (14) and the air supply device (68) has a second air-guiding portion (58) with which the air is conducted along the at least one closed side (14).
7. Open fireplace according to claim 6,
   characterised in that the air supply device (68) is provided on the at least one closed side (14) with a first air inlet (62).
8. Open fireplace according to any one of claims 1 to 7,
   characterised in that the fire chamber (12) has at least one bottom surface (22) and the air supply device (68) has a third air-guiding portion (60) with which the air is conducted along the bottom surface (22).
9. Open fireplace according to claim 8,
   characterised in that the air supply device (68) is provided on the bottom surface (22) with a second air inlet (64).
10. Open fireplace according to claim 7 or 9,
    characterised in that the first or second air inlet (62, 64) is configured so as to be optionally closable by a blind cover (66).

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