Fireplace with suspended hearth

Abstract

The invention relates to a fireplace (1), comprising: a hearth (2) suspended from a support (3), the hearth (2) being laterally delimited by a peripheral wall (21) provided with at least one combustion air inlet, an exhaust pipe (4) for exhausting combustion gases, the exhaust pipe (4) comprising a bottom (40) fixed to the top of the hearth (2) and a top (42) opposite the bottom (40). According to the invention, the fireplace comprises: at least one combustible fluid burner (5) arranged in the hearth (2) opposite the at least one air inlet, a combustible fluid supply column (6) extending between a first end (60) connected to a combustible fluid source and a second end (61) connected to at least one burner (5), the supply column (6) extending from the top (40) of the exhaust pipe (4) downward through the exhaust pipe (4) to its bottom (42) and opening in the hearth (2) so as to convey the combustible fluid from the combustible fluid source to the at least one burner (5).

Description

Technical Field

[0001] The present invention belongs to the field of fireplaces, more particularly, to the field of decorative fireplaces.

[0002] In particular, the invention relates to a fireplace comprising a suspended hearth, the combustion of which is achieved by means of a combustible fluid. Background Art

[0003] It is scientifically recognized that fireplaces with open hearths have several disadvantages. First, they provide low efficiency in the generation of heat energy, between 15% and 20%. In addition, open hearths lead to incomplete combustion of wood, which results in the emission of large amounts of fine particle pollutants. Open hearths contribute to the emission of these particles into the residence and atmosphere through the exhaust pipe. These fine particles pose a significant health and environmental risk. In addition, fireplaces with open hearths increase the risk of fire in the room where they are installed.

[0004] These disadvantages have led to changes in legislation, particularly in Europe, aimed at limiting or even banning the use of fireplaces with open hearths.

[0005] There are currently decorative and iconic fireplaces with suspended hearths. This type of fireplace consists, on the one hand, of an open hearth with an elegant and aesthetic shape and, on the other hand, of a combustion gas exhaust pipe connected to the top of the open hearth. The exhaust pipe also serves as a suspension element for the hearth relative to a support generally formed by the ceiling.

[0006] Some of these decorative, iconic fireplace styles have hearths that are specifically shaped, such as an oblate shape. Additionally, these hearths often include openings that match their shape, thus complicating the installation of windows in order to convert such hearths to closed or recessed hearths.

[0007] Taking these problems into account, the Applicant has proposed a technical solution that allows the continued production or use of decorative and iconic fireplaces while overcoming the drawbacks of fireplaces with an open wood-burning hearth. Summary of the invention

[0008] Therefore, the present invention relates to a fireplace comprising:

[0009] - a furnace suspended from supports, said furnace being laterally delimited by a peripheral wall provided with at least one combustion air inlet, and

[0010] - an exhaust pipe for exhausting the combustion gases, the exhaust pipe being fixed to a support and comprising a bottom portion fixed to the top portion of the furnace and a top portion opposite the bottom portion.

[0011] The fireplace according to the present invention is characterized by comprising:

[0012] - at least one combustible fluid burner, arranged in said furnace, opposite to at least one air inlet, and

[0013] - a combustible fluid supply column extending between a first end connected to a combustible fluid source and a second end connected to at least one burner, the supply column passing through the discharge pipe from the top downward to the bottom thereof and opening in the furnace so as to transport the combustible fluid from the combustible fluid source to at least one burner.

[0014] The use of a combustible fluid burner does not generate fine particles due to the incomplete combustion of the combustible solids. In this respect, the conversion of a wood-burning fireplace into a fireplace using a combustible fluid can overcome the health and energy disadvantages of an open wood-burning hearth. Furthermore, in order to maintain the aesthetic qualities of the iconic style, the combustible fluid supply column is at least partially integrated in the discharge pipe. Furthermore, according to the invention, the discharge pipe preferably constitutes the only hanging element of the hearth.

[0015] According to a first feature of the invention, the supply column comprises a supply pipe and thermal insulation surrounding the supply pipe between each end of the supply column. The thermal insulation allows the supply column to be maintained at a temperature below a given threshold. Above this threshold, the flammable fluid may ignite in the supply pipe.

[0016] In particular, the thermal insulation comprises at least one heat exchanger surrounding the supply pipe, the heat exchanger extending at least between each end of the supply column. Preferably, the thermal insulation comprises at least two heat exchangers, a first heat exchanger surrounding the supply pipe and a second heat exchanger surrounding the first heat exchanger, and each heat exchanger extending at least between each end of the supply column.

[0017] According to the invention, the two heat exchangers are arranged concentrically. This configuration allows the first heat exchanger to be evenly insulated.

[0018] Furthermore, the thermal insulation comprises at least one air inlet which is arranged in the region of the furnace and which supplies at least one heat exchanger from outside the furnace and generates a rising air flow within the heat exchanger.

[0019] The heat exchanger is preferably an air heat exchanger. Thus, this configuration generates an ascending double airflow, which helps to keep the temperature of the supply pipe below a given threshold.

[0020] According to a second characteristic of the invention, the fireplace comprises, on the one hand, an attachment plate fixing the supply duct to a support and, on the other hand, a sleeve fixed to the attachment plate, which surrounds the discharge duct at a given distance and diffuses the warm air.

[0021] According to a third characteristic of the invention, the hearth is rotatably mounted relative to the discharge pipe and / or a supply column extending to the base of the hearth, the base of the hearth defining the bottom of the hearth. Thus, the fireplace comprises a plate arranged in the base of the hearth, pivoting relative to the base of the hearth, and the supply column is mounted fixed to this pivot plate. The pivot plate and the base are advantageously perforated to allow air to be sucked towards the supply column.

[0022] According to a fourth feature of the invention, the discharge pipe is fixed to the support by its top, so that the discharge pipe serves as a suspension element of the furnace relative to the support. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other special features and advantages will appear in the following Figures 1 to 3 In the detailed description of the non-limiting embodiment of the present invention shown, in which:

[0024] Figure 1 is a schematic diagram of a longitudinal cross section of a fireplace with a suspended hearth according to an embodiment of the present invention.

[0025] Figure 2 yes Figure 1 Schematic representation of a cross section AA of an exhaust pipe of a fireplace with a suspended hearth.

[0026] Figure 3 Yes Figure 1 Schematic diagram of a longitudinal cross-section of the top of the discharge pipe of a fireplace, in which the various gas flows are shown.

[0027] Figure 4 is a perspective view of a fireplace with a suspended hearth according to an embodiment of the present invention.

[0028] Figure 5 yes Figure 4 Illustration of an attachment plate for a fireplace.

[0029] Figure 6 yes Figure 4 Illustration of a fireplace hearth. DETAILED DESCRIPTION

[0030] like Figures 1 to 6As shown, the invention relates to a fireplace 1 comprising a hearth 2 suspended on a support 3. In general, the support 3 can be formed by a wall, a partition, a ceiling, a floor, a ceiling fixture, etc. With respect to the ceiling, the floor or the ceiling fixture, such a fireplace 1 can be positioned close to a wall or in front of a glass wall, or in the middle of a room. Thus, a fireplace 1 of this type has a decorative and aesthetic appearance and can also provide heat to the room in which it is installed.

[0031] In order to achieve a decorative function, the furnace 2 may have a specific shape. Figure 1 , Figure 3 , Figure 6 In the example of the embodiment, the furnace 2 is in an oblate shape. However, the furnace 2 can be in various three-dimensional geometric shapes, such as a quadrilateral, a sphere, a pyramid, or a cylinder.

[0032] exist Figure 1 In the example shown, the hearth 2 is formed by a housing 20. The housing 20 comprises a peripheral wall 21 which delimits the hearth 2 transversely. The housing 20 also comprises a base 22 which delimits the bottom of the hearth 2. When the fireplace 1 is suspended, the base 22 of the hearth 2 is at a given distance from the floor. Preferably, the base 22 does not touch the floor of the room. Finally, the housing 20 comprises a top wall 23 which delimits the top of the hearth 2. The top wall 23 belongs to the top of the hearth 2. At the same time, the base 22 belongs to the bottom of the hearth 2.

[0033] At least one air inlet opening 24 is provided on the peripheral wall 21. The air A from the air inlet opening is used as an oxidant for the combustion process. In this example, the air inlet opening is formed by an opening 24 arranged in the peripheral wall 21. This opening 24 defines the front of the furnace 2. In this example, the opening 24 is open. However, according to a variant of the present invention not shown, a device for complete or partial closure can be provided in the area of ​​this opening 24 to limit access to the furnace 2. The closure device can preferably be opened and reclosed. As an indication, the closure device can, for example, be formed by a window or a grille.

[0034] The fireplace 1 further comprises a discharge pipe 4. In this example, the discharge pipe 4 is cylindrical. Preferably, the discharge pipe 4 is made of a non-ductile material having heat conducting properties. As an indication, the discharge pipe 4 can be produced from a metal or a metal alloy such as steel, cast iron, etc.

[0035] The exhaust pipe 4 ensures in particular that the combustion gases B are discharged to the outside of the room. Therefore, the exhaust pipe 4 comprises a bottom 40 fixed to the top of the furnace 2. Of course, the exhaust pipe 4 comprises an opening 41 communicating with the housing 20 in the region of the junction between the exhaust pipe 4 and the furnace 2. The combustion gases B escape from the furnace in an ascending airflow (e.g. Figure 1 and Figure 3 shown).

[0036] Furthermore, the discharge pipe 4 comprises a top portion 42. The top portion 42 is opposite the bottom portion 40. The top portion 42 is fixed to the support 3. In this example, the top portion 42 is fixed to the support by means of an attachment plate 43. Figure 4 and Figure 5 In the example shown, the attachment plate 43 is annular. In practice, the attachment plate 43 can be fixed to the discharge pipe 4 mechanically or by welding.

[0037] like Figure 4 and Figure 5 As shown, the fireplace 1 further comprises a sleeve 44 fixed to the attachment plate 43. The sleeve 44 surrounds the discharge pipe 4. In this example, the sleeve 44 extends a given distance from the plate 43 in the direction of the bottom 40 of the discharge pipe 4. Preferably, the sleeve 44 comprises a hollow body extending annularly between the peripheral wall of the discharge pipe 4 and the outer wall of the sleeve 44.

[0038] exist Figures 1 to 6 In the example described in , the discharge pipe 4 serves as a suspension element of the hearth 2 relative to the support 3. Thus, the discharge pipe 4 extends downwardly from the support 3 to the hearth 2. Preferably, the discharge pipe 4 extends longitudinally between the support 3 and the hearth 2. However, depending on the style and / or type of installation of the fireplace 1, the discharge pipe 4 may not extend in a straight line.

[0039] Furthermore, in order to discharge the combustion gas B to the outside of the room and / or building, the discharge pipe 4 extends to the outside of the room and / or building through an exhaust pipe.

[0040] The fireplace 1 comprises at least one combustible fluid burner 5. Preferably, the burner 5 is configured to burn a combustible fluid C, such as city gas, propane, butane, etc. However, a burner configured to burn ethanol or bioethanol may also be used. In this example, the burner 5 is arranged in the hearth 2. In particular, the burner 5 is arranged opposite to the opening 24. Therefore, the burner 5 uses the air A from the opening 24 as an oxidant. In addition, this configuration allows the blazing flames generated by the burner 5 to spread through the opening 24 in the room where the fireplace 1 is installed.

[0041] exist Figure 6 In the example of , the fireplace 1 comprises a curved burner 5 . In this example, the curvature of the burner 5 follows the curvature of the housing 20 and the opening 24 .

[0042] Using the burner 5 for the combustible fluid C can reduce fine particle emissions associated with incomplete combustion of wood. In this regard, the burner 5 for the combustible fluid C helps to overcome the shortcomings of the wood-burning fireplace described in the background of this document.

[0043] like Figures 1 to 3As shown, the fireplace 1 comprises a supply column 6. The supply column 6 is particularly configured to supply a combustible fluid to the burner 5. Therefore, the supply column 6 extends between a first end 60 connected to a source of combustible fluid and a second end 61 connected to at least one burner 5. In this example, the source of the combustible fluid C is located upstream of the support 3. The combustible source may include a local tank, such as a gas tank. However, preferably, the source of the combustible fluid C is a public supply network, for example a network supplying city gas.

[0044] In this example, the supply column 6 is arranged downwardly through the discharge pipe 4. More precisely, the supply column 6 extends at least partially within the opening 41 of the discharge pipe 4. Figures 1 to 3 As shown, the supply column 6 extends along an axis that is radially offset relative to the central axis of the discharge pipe 4. In this case, the supply column 6 initially extends inside a sleeve 44. The supply column 6 then extends longitudinally from the top 42 of the discharge pipe 4 to the bottom 40. Preferably, the supply column 6 extends beyond the bottom 40 and opens in the furnace 2. Finally, the supply column 6 extends to a plate 25 arranged in the region of the base 22 of the furnace 2. In the region of this plate 25, the supply column 6 is connected to at least one burner 5.

[0045] Advantageously, the fact that the supply column 6 extends inside the discharge pipe 4 contributes to providing a compact and aesthetically pleasing technical solution for supplying the burner 5 with the combustible fluid.

[0046] exist Figures 1 to 3 In the example shown, the supply column 6 comprises a supply pipe 62 extending from a source of combustible fluid to at least one burner 5. In particular, the supply pipe 62 reaches the plate 25 via the attachment plate 43, the sleeve 44 and the supply column 6 in sequence. In the region of the plate 25, the supply pipe 62 is extended by a flexible supply coupling 63 connected to at least one burner 5. Thus, the combustible fluid reaches the burner 5 via the supply column 6 in a downward airflow C. Furthermore, the flexible supply coupling 63 is connected to the supply pipe 62 on the one hand and to the at least one burner 5 on the other hand by a sealed mechanical connection. For example, such a sealed mechanical connection can be produced by a compression nut that holds the fitting in place during the rotation of the furnace 2.

[0047] The supply pipe 62 can be formed by a cylindrical pipe made of a non-ductile material covered with a heat-insulating polymer material. For example, the supply pipe 62 is made of a metal material such as stainless steel or aluminum. The supply pipe 62 can transport combustible gases such as city gas, propane, butane, etc.

[0048] Advantageously, the supply column 6 comprises thermal insulation 7. In this case, the thermal insulation 7 surrounds the supply pipe 62 between each end 60, 61 of the supply column 6. In this respect, the thermal insulation 7 allows the supply pipe 62 to be thermally insulated from the combustion gases B circulating in an upward flow in the discharge pipe 4. This is because the combustion gases B can generally reach a temperature of 150° C. to 300° C.

[0049] However, at such a temperature, the combustible fluid is likely to ignite by simple transfer of heat energy of the rising combustion gases B. However, the thermal insulation 7 can reduce the transfer of heat energy. This is because the thermal insulation 7 keeps the supply pipe 62 at a temperature below a given threshold temperature. More precisely, the thermal insulation 7 keeps the supply pipe 62 at a temperature below 60°C. Preferably, the thermal insulation 7 allows the supply pipe 62 to be kept at a temperature below 50°C.

[0050] With this in mind, the insulation device 7 comprises at least one heat exchanger 70. The heat exchanger 70 surrounds the supply pipe 62. The heat exchanger 70 thus insulates the supply pipe 62 from the combustion gases B. In this example, the heat exchanger 70 extends at least between each end 60, 61 of the supply column 6. In practice, the heat exchanger 70 extends from the plate 25 located in the furnace 2 to the sleeve 44. In practice, the heat exchanger 70 passes through the furnace 2 and the discharge pipe 4 in sequence.

[0051] Preferably, if Figures 1 to 3 As shown, the thermal insulation device 7 comprises at least two heat exchangers 70, 70a, 70b. In this advantageous configuration, the first heat exchanger 70a surrounds the supply pipe 62. At the same time, the second heat exchanger 70b surrounds the first heat exchanger 70a. It should be noted that the peripheral wall of the second heat exchanger 70b delimits the supply column 6 in the furnace 2 in the transverse direction, and also delimits the supply column 6 in the discharge pipe 4.

[0052] The heat exchangers 70, 70a, 70b are fitted inside each other. Furthermore, the supply pipe 62 is fitted in the first heat exchanger 70a. This configuration allows the thermal insulation of the supply pipe 62 to be optimized.

[0053] In addition, Figure 2 In the example shown, the two heat exchangers 70, 70a, 70b are arranged concentrically. Advantageously, the second heat exchanger 70b allows the first heat exchanger 70a to be cooled. Therefore, the supply pipe 62 can be in contact with the wall of the first heat exchanger 70a without risk. In this example, the supply pipe 62 consists of a flexible semi-rigid pipe. The concentric arrangement of the heat exchangers ensures uniform thermal insulation of the peripheral wall radially delimiting the first heat exchanger 70a.

[0054] In this example, each heat exchanger 70, 70a, 70b is formed by a pipe. This pipe is preferably made of a non-ductile material such as a metal material. For example, the pipe can be made of stainless steel, aluminum, etc. In addition, each pipe can be covered with a high temperature resistant insulation coating. For example, ceramic cloth, glass fiber, low temperature material (microtherm), elastomer, etc. can be used.

[0055] As an example, the first heat exchanger 70a may have a cross section at least 1.5 times greater than that of the supply pipe 62. Meanwhile, the cross section of the second heat exchanger 70b may have a cross section at least 1.3 times greater than that of the first heat exchanger 70a.

[0056] exist Figures 1 to 3 In the example shown, each heat exchanger 70, 70a, 70b is an air heat exchanger. In this case, the thermal insulation 7 comprises at least one air inlet. In this example, the air inlet is arranged in the region of the furnace 2. More precisely, this air inlet is arranged in the region of the plate 25. Therefore, the plate 25 is perforated.

[0057] Similarly, the base 22 also comprises at least one air inlet 26, which is advantageously arranged on the same axis as the air inlet of the thermal insulation 7. These air inlets 26 supply the at least one heat exchanger 70, 70a, 70b from the outside of the furnace 2. These features contribute to the creation of an ascending air flow D, E in the at least one heat exchanger 70, 70a, 70b. This ascending air flow is called cold air, since it comes directly from the outside of the furnace 2. In fact, each heat exchanger 70, 70a, 70b has an air inlet in the region of the plate 25. This configuration enables the creation of a double flow of cold air D, E in the supply column 6. The double flow of cold air D, E contributes to ensuring optimal insulation of the supply pipe 62.

[0058] Table 1 below compares the temperatures of the supply pipe 62 measured at multiple heights, on the one hand, for a first embodiment of the invention, referred to as a single-flow configuration, in which the supply column 6 is provided with a single heat exchanger 70, 70a, 70b, and on the other hand, for a second embodiment, referred to as a dual-flow configuration, in which the supply column 6 comprises two heat exchangers 70, 70a, 70b.

[0059] Table 1

[0060]

[0061] According to these results, in the single-flow configuration, the temperature of the supply pipe 62 can vary between 41°C and 72°C, while the dual-flow configuration allows the temperature variation of the supply pipe 62 to be limited to between 21°C and 24°C.

[0062] Thus, the dual flow configuration allows the temperature of the supply pipe 62 to be maintained at a threshold above 30° C. and below 60° C. Thus, the dual flow configuration allows the risk of ignition of the combustible fluid C through heat energy transfer from the combustion gases B to be reduced or even eliminated.

[0063] like Figure 3 As shown, at least one heat exchanger 70, 70a, 70b comprises an exhaust outlet 71. This exhaust outlet 71 opens in the exhaust pipe 4. In particular, the exhaust outlet 71 is arranged close to the first end 60 of the exhaust pipe 4. In this example, the second heat exchanger 70b comprises an exhaust outlet 71 opened at the top of the opening 41 of the exhaust pipe 4. Therefore, the cold air E enters the second heat exchanger 70b through the air inlet, passes upward through the supply column 6 to the exhaust outlet 71. In the area of ​​the exhaust outlet 71, the rising air E is mixed with the combustion gas B and then discharged to the outside through the exhaust pipe.

[0064] According to the invention, each heat exchanger 70, 70a, 70b extends at least between each end 60, 61 of the supply column 6. More precisely, the first heat exchanger 70a extends from the plate 25 to the sleeve 44. On the other hand, the second heat exchanger 70b extends from the plate 25 to the junction between the supply column 6 and the sleeve 44.

[0065] like Figure 1 and Figure 3 As shown, the first heat exchanger 70a opens in the sleeve 44. The sleeve 44 includes openings arranged in its peripheral wall. Therefore, the sleeve 44 diffuses the warm air previously passed from the plate 25 through the first heat exchanger 70a. Advantageously, this creates a natural air circulation within the first heat exchanger 70a. The cold air D enters the first heat exchanger 70a in the air inlet area. When entering the air inlet area, the cold air D is at ambient temperature. When passing through the first heat exchanger 70a, the cold air D is warmed to be discharged from the sleeve 44 into a room with a temperature between 35°C and 40°C. By diffusing the warm air in the ceiling area of ​​the room, it helps to evenly diffuse the temperature generated by the combustion. This feature improves the thermal comfort of the room where the fireplace 1 is installed.

[0066] like Figure 4 As shown, the furnace 2 is rotatably mounted relative to the discharge pipe 4. To this end, the furnace 2 is connected to the discharge pipe via a rotary mechanical connection, such as a cylinder / cylindrical pivot linkage. In addition, the furnace 2 can also be rotatably mounted relative to the supply column 6. Therefore, the plate 25 is pivotally mounted relative to the base 22 of the furnace 2. To this end, the plate 25 can be engaged in a rotary mechanical linkage. For example, the rotary mechanical linkage can be formed by a rotating disk with ball bearings or a disk that frictionally cooperates with the bearings, etc.

Claims

1. A fireplace (1), include: - a furnace (2) suspended from supports (3), said furnace (2) being laterally delimited by a peripheral wall (21) provided with at least one combustion air inlet, and - an exhaust pipe (4) for exhausting the combustion gases, the exhaust pipe (4) being fixed to a support (3) and comprising a bottom (40) fixed to the top of the furnace (2) and a top (42) opposite the bottom (40), the exhaust pipe (4) being fixed to the support (3) by its top (42), so that the exhaust pipe (4) serves as a suspension element of the furnace (2) relative to the support (3), The invention is characterized by comprising: - at least one combustible fluid burner (5) arranged in said furnace (2) opposite to at least one air inlet, and - a combustible fluid supply column (6) extending between a first end (60) connected to a combustible fluid source and a second end (61) connected to at least one burner (5), the combustible fluid supply column (6) comprising a supply pipe (62) and a thermal insulation device (7), the thermal insulation device (7) surrounding the supply pipe (62) between the first end (60) and the second end (61) of the combustible fluid supply column (6), the combustible fluid supply column (6) passing through the discharge pipe (4) from the top (42) of the discharge pipe (4) downward to the bottom (40) thereof and opening in the furnace (2) so as to transport the combustible fluid from the combustible fluid source to the at least one burner (5).

2. The fireplace (1) according to claim 1, It is characterized in that The thermal insulation device (7) comprises at least one heat exchanger (70a, 70b) surrounding the supply pipe (62), and the heat exchanger (70a, 70b) extends at least between the first end (60) and the second end (61) of the combustible fluid supply column (6).

3. The fireplace (1) according to claim 2, It is characterized in that The thermal insulation device (7) includes at least two heat exchangers (70a, 70b), a first heat exchanger (70a) surrounds the supply pipe (62), and a second heat exchanger (70b) surrounds the first heat exchanger (70a), and each heat exchanger (70a, 70b) extends at least between a first end (60) and a second end (61) of the combustible fluid supply column (6).

4. The fireplace (1) according to claim 3, It is characterized in that The two heat exchangers (70a, 70b) are concentrically arranged.

5. A fireplace (1) according to any one of claims 2 to 4, It is characterized in that The insulation device (7) comprises at least one air inlet (26) arranged in the region of the furnace (2), the air inlet (26) supplying at least one heat exchanger (70a, 70b) from outside the furnace (2) and generating an ascending air flow in the heat exchanger (70a, 70b).

6. The fireplace (1) according to claim 1, It is characterized in that include: - an attachment plate (43) to secure said supply pipe (62) to the support (3), and - A sleeve (44), fixed to the attachment plate (43), which surrounds the discharge pipe (4) at a given distance and diffuses the warm air.

7. The fireplace (1) according to claim 1, It is characterized in that The furnace (2) is rotatably mounted relative to the discharge pipe (4) and / or a combustible fluid supply column (6) extending to a base (22) of the furnace (2), the base (22) of the furnace (2) defining the bottom of the furnace (2).

8. The fireplace (1) according to claim 7, It is characterized in that The invention comprises a pivot plate (25) arranged in the base (22) of the furnace (2), the pivot plate (25) pivots relative to the base (22) of the furnace (2), and the combustible fluid supply column (6) is mounted and fixed to the pivot plate (25).

9. The fireplace (1) according to claim 8, It is characterized in that The pivot plate (25) and the base (22) are perforated to allow air to be drawn towards the combustible fluid supply column (6).

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