AT525025A1 - Outdoor fire pit - Google Patents

Abstract

The invention relates to an outdoor fireplace comprising a burner (3) for pourable solid fuel. In addition to the burner (3), the fireplace also includes a grate (4) for burning logs, the burner (3) and grate (4) being designed separately from one another, the burner (3) having a flame opening (9) at the top and the grate (4) has a grid-like surface (11) for supporting logs to be burned, the grid-like surface (11) covering the flame opening (9) at the top and extending laterally away from the surface area covering the flame opening (9).

Description

description

The invention relates to an outdoor fireplace,

comprising a pourable solid fuel burner.

AT 516193 B1 and AT 521754 A1 show a burner for pourable solid fuel on a fireplace for outdoor use. The burner for pourable solid fuel is a vessel, the interior of which forms the combustion chamber and which is filled with pourable solid fuel before it is ignited. Typically, the bottom of the combustion chamber is partially pierced by openings for the flow of primary air. Typically, the combustion chamber is partially covered by a cover having a centrally located opening which is the burner flame hole. Typically, the upper part of the lateral surface surrounding the combustion chamber is partially broken through by openings for the inflow of secondary air, or there is an annular open gap between the lateral surface and the cover. Such burners are very advantageous in terms of ease of use and low risk of fire. They lead to a significantly hotter and smokeless flame than a grate on which logs are burned. On top of that it is

Fire behavior largely independent of weather conditions.

Loose, solid fuel within the meaning of this document is fuel in the form of pieces of combustible material that are a few millimeters to a maximum of two centimeters in size. A very typical pourable solid fuel are so-called pellets, namely lumps several millimeters in size, which are formed by pressing

Chips and / or fibers are formed from wood.

Log wood is not suitable as a fuel for the fireplace according to AT 516193 B1 and AT 521754 A1 because it is too bulky and has a comparatively small surface area in relation to the volume

Has. Log wood in the sense of this document is wood as a fuel

1

Pieces that are several decimeters in size, at least in one direction

are.

WO 2011042595 A1 and WO 9829686 A1 show outdoor fireplaces that are suitable both for pellets and for logs. The combustion chamber is surrounded by a vessel that is completely open at the top, the outer surface of which is designed either like a sieve for the inflow of air or is broken through by a slot running vertically from the very bottom to the very top. Disadvantages of these very simple designs are that burn-off and flying sparks are very strongly influenced by weather conditions - especially by wind - and fluctuate with them, and that very often over longer periods

has to contend with heavy smoke development for a long time.

AT 405760 B shows a combination of a solid fuel boiler and a pellet burner, the primary air flow of which can be driven by a fan, as part of a heating boiler system to be arranged inside a building. The combustion chambers of the solid fuel boiler and pellet burner are connected by a horizontally running flame tube, through which the combustion chamber of the solid fuel burner can be

boiler can be (additionally) heated.

Proceeding from this state of the art, the object on which the invention is based is to design a fireplace for outdoor use, which includes a combustion chamber for pourable solid fuel, in such a way that logs can optionally also be used as fuel. Compared to the fireplaces known from WO 2011042595 A1 and WO 9829686 A1, it should be possible to better address weather conditions and

the burn should be associated with less smoke.

To solve the task is proposed the hearth both

with a loose solid fuel burner - as typically

2

specifically pellets - as well as with a grate for the support of

to be equipped with logs to be burned, - whereby the burner and the grate are designed separately from each other,

- where the flame opening of the burner is an opening of the combustion chamber

mes up

- Where the grate covers the flame opening at the top and from the

Flame opening extends laterally away.

This arrangement means that the main advantage of burners for pourable solid fuel (pellets) compared to burning logs on a grate, namely a largely weather-independent, very hot, very low-smoke flame, can not only be used additively for the combustion of logs in a technically easy to implement manner, but can also be extended to the burning of logs, so that logs are also largely independent of

the weather with a very hot, low-smoke flame.

According to a preferred further development, said grate is attached to other parts of the hearth by a plug-in connection.

kert, from which it can be released by moving it upwards.

According to a preferred further development, the grate has a detachable insert part in the form of a flat lattice, which

essentially covers only said flame opening.

The invention is based on drawings of an advantageous embodiment of an exemplary fireplace according to the invention

explained in more detail:

Fig. 1 shows an exemplary fireplace according to the invention in an exploded view, with the individual parts compared to their actual position in relation to each other in vertical

direction are shown apart.

3

Figure 2 shows a sectional view of the hearth of Figure 1, the sectional plane having a vertical plane of symmetry

the fire pit is.

Arranged from bottom to top, the fireplace according to Fig. 1 comprises a base 1, a housing 2, a burner 3 for pourable solid fuel, a grate 4 and an insert part 5, which is a detachable part of the grate 4

is.

The exemplary base 1 is typically made of sheet steel and has approximately the shape of a prismatic box open at the top. It directly carries the housing 2 and the burner 3. It can be equipped with feet or with wheels on its underside, by which it is supported on its subsoil—typically a patio floor. A function of the base 1 is also to collect ash which trickles down from the burner 3 and from a lower opening of the housing 2.

to catch.

In principle, burner 3 is constructed like the burners presented at the outset with reference to AT 516193 B1 and AT 521754 A1. It is designed to burn loose solid fuel, typically pellets. The combustion chamber 6 of the burner 3 is bordered at the bottom by a floor grating 7 (that is to say a surface broken through by openings in the manner of a grid) and at the side by a lateral surface 8 . The combustion chamber 6 is open at the top through a flame opening 9 . The burner 3 is preferably--as shown--designed as a gasification burner. "Gasifier burner" in this sense means that the combustion of the loose solid fuel takes place in two phases, namely in a first phase, in which the fuel mainly smolders using incoming primary air instead of burning properly flaming, and in a second phase, wherein generated by the first phase

ten hot exhaust gas flow, which contains many combustible gas components

4

holds, secondary air is supplied so that it leads to a second,

"secondary" combustion occurs.

In the example shown, the burner 3 has both a bottom grate 7 - i.e. a grid-like bottom surface with openings - and secondary air openings 10 in the upper area of the lateral surface 8. In normal operation, loose solid fuel smolders in the lower area of the combustion chamber and emits combustible gas , which rises. Oxygen is added to the combustible gas through the secondary air openings 10, as a result of which, in addition to the glow mentioned, another—“secondary”—combustion takes place and the fire generated thereby flares out of the combustion chamber 6 through the flame opening 9 upwards. The combustion processes in burner 3, once they are well under way - which can be done within a few minutes after ignition using a commercially available ignition cube - are smoke-free and largely independent of whether there is wind or rain in the vicinity. Mainly due to the secondary combustion, the flame of the burner 3 emerging from the flame opening 9 is very hot and largely free of smoke.

dung.

According to the invention, the grate 4 is also provided as part of the hearth, which is used for burning logs and extends in its vicinity above the burner 3, covers the flame opening 9 and extends laterally away from the area above the flame opening 9. Lumber in the sense of this document is wood in the form of pieces, the larger dimension of which is typically several decimeters. The core element of the grate 4 is a lattice-like surface 11, ie a surface with openings 12, which is intended to carry the piece of wood to be burned. The openings 12 serve to allow combustion air to flow from below to the piece of wood lying on the grid-like surface 11 11 and ash in the opposite direction

to let through. The grid-like surface 11 is located

5

so close above the flame opening 9 of the burner 3 that flames which lick upwards out of the flame opening 9 during operation

protrude at least up to this grid-like surface 11 .

In the example shown, the grate 4 has sheet metal walls 13 that protrude laterally downwards and have extensions 14 at their lower end that can be inserted from above into slots 15 in the housing 2, so that a detachable plug-in connection is created between the grate 4 and the housing 2 is formed. This makes it easy to detach the grate 4 if necessary - for example for cleaning purposes from the housing 2 or even the burner 3 without the grate 4

to operate.

As shown, the grid-like surface 11 of the grate 4 preferably has an opening 16 on that part which is located exactly above the flame opening 9 , the shape and size of which approximately corresponds to the shape and size of the cross-sectional area of the flame opening 9 . This opening 16 can optionally be covered by the already mentioned insert part 5, which itself is also a grid-like surface. As can be seen above all from FIG. 1, the insert part 5 has laterally downwardly protruding lugs which can optionally be inserted from above into slit-shaped openings in the grid-like surface 11, so that a detachable plug-in connection between the grid-like surface 11 and the insert

clause 5 is formed.

If the insert part 5 is not inserted, flames can flicker upwards unhindered from the flame opening of the burner 3 . When the insert 5 is inserted, logs can also be placed directly above the flame opening 9 and thus well through

Flames from the flame opening 9 are preheated and ignited.

In the example shown, the housing 2 is designed essentially as a sheet metal surface in the form of the lateral surface of a truncated cone. It carries the grate 4 and also surrounds the firing area

above the grid 4 and thus shades it somewhat from the wind. The GE-

6

housing 2 also catches ash that falls through the grate 4 down

trickles down.

The very hot, very low-smoke flame, which is generated by the burner 3 and blazes upwards from its flame opening 9, is extremely advantageous both when igniting logs that are on the grate 4 and when burning them regularly. This flame not only causes the log wood to dry and ignite. It also means that fire and exhaust gases, which result directly from the burning of the logs, are sucked into the volume area, which extends upwards above the flame opening 9, and are mixed there with the volume of the hot flame from the burner 3 . This results in post-combustion of the gaseous and/or droplet-like and/or dust-like combustion products from the wood log combustion. This post-combustion means a completion of the combustion and thus both an increase in the yield of thermal energy and a significant to drastic reduction in smoke and

Particulate matter.

The firing can optionally be combined with burner 3 and grate 4 or only with burner 3 or only with grate 4

be operated alone.

The combination shown according to the invention of a burner 3 for pourable material and a grate 4 for logs means that, in addition to the ability to select and add between or two different fuels, significant further advantages can be achieved. The most important of these further advantages are more independence from weather conditions, more yield of thermal energy

low-smoke combustion.

7

Claims (6)

patent claims 1. Outdoor fire pit which has one burner (3) for pourable solid fuel, characterized in that —- the fireplace also has a grate (4) for burning Log wood includes, where - Burner (3) and grate (4) designed separately from each other are, wherein - the burner (3) has an overhead flame opening (9). - And the grate (4) has a grid-like surface (11) for the carrying gene of the log wood to be burned, - The grid-like surface (11) covering the flame opening (9) at the top and from which the flame opening (9) overlaps Ckenden surface area extends laterally away. 2. Fireplace according to claim 1, characterized in that the grate (4) has downwardly projecting extensions (14) which are part of a detachable plug-in connection with which the grate (4) can be detachably connected to another part of the fireplace is. 3. Fireplace according to claim 1 or 2, characterized in that the grid-like surface (11) has an opening (16) in that area which is located exactly above the flame opening (9), which is approximately the same shape and size in shape and size Size of the cross-sectional area of the flame opening (9) matches, and that this opening (16) through an insert part (5), which as a surface with a plurality of openings is formed, can be covered. 8th 4. Fireplace according to claim 3, characterized in that the insert part (5) and the grid-like surface (11) by a detachable connector can be connected. 5. Fireplace according to one of claims 1 to 4, characterized indicates that the burner (3) is a carburettor burner. 6. Fireplace according to one of claims 1 to 5, characterized in that the burner (3) has a combustion chamber (6) for receiving and burning off pourable solid fuel, the bottom of the combustion chamber (6) having openings for the flow is pierced by primary air, the combustion chamber (6) being laterally delimited by a lateral surface (8), the upper part of the lateral surface (8) being partially pierced by openings (10) for the inflow of secondary air and/or located between the lateral surface (8) and a cover that partially covers the combustion chamber (6) at the top. there is an open gap for the inflow of secondary air. 9