BURNER FOR GAS STOVE OR COOKER

Abstract

The invention provides a premixer burner for a gas stove comprising a gas injector (12), a venturi-effect tubular mixer (20, 22), and a burner support (26), one end of which is closed by a cap (28). The tubular mixer is characterized in that it comprises an outer tube (20) and an inner tube (22) with a venturi effect, coaxial with the outer tube (20). The inner tube (22) has at least one axial slot (60) in its thickness, the width of which gradually increases from rear to front within the inner tube (22) to progressively increase the effective cross-sectional area within the tubular mixer (20, 22). By means of this venturi effect, air is drawn in by the gas, which is then injected to produce the air-gas fuel mixture in the burner (10). Figure for the abstract: 2

Description

Title of the invention: BURNER FOR GAS STOVE OR COOKER Technical field of the invention

[0001] The invention relates to a burner for a gas stove or cooker.

[0002] The invention relates more particularly to a burner enabling the implementation of environmentally friendly and "low-carbon" manufacturing techniques. Technical background

[0003] The invention relates in particular to a burner called a "premixer burner" of the type comprising a gas injector which is connected to a venturi effect tubular mixer which is itself connected to a support, generally in the form of a pot or cylindrical cup, the upper face of which is open and closed by a cap attached to close this upper face.

[0004] In a known manner, all or part of these components are manufactured in a foundry by metal casting, in particular in cast iron or brass.

[0005] This type of manufacturing has many disadvantages.

[0006] First of all, it is totally unsuitable for the production of small series of burner models, because it requires the implementation of molds corresponding to each range of burners.

[0007] In addition, production costs are very high and transport costs related to the weight of parts and components are very high, as are the various negative impacts on the environment, whether it be transport but also molding and foundry techniques with the impacts related in particular to the various polluting emissions and the significant energy consumption linked to their implementation.

[0008] Moreover, the realization of the internal conical or truncated conical profile enabling the desired venturi effect requires the implementation of complex machining techniques.

[0009] Document FR2025027A1 proposed implementing alternative technologies for the production of the burner body with its venturi effect tubular mixer, but the proposed solution of cutting a sheet metal piece, folded and crimped is very complex and not well suited to the simple production of ranges of burners of different dimensions and heating capacities.

[0010] The invention aims to remedy all or part of these drawbacks. Summary of the invention

[0011] The invention provides a burner for a gas stove or cooker comprising a gas injector which is connected to a rear end of a tubular effect mixer venturi whose front end is connected to a support, characterized in that the tubular mixer comprises: - an outer casing tube whose internal section is cylindrical; - and an inner tube with a venturi effect coaxial with the outer tube; — which is adjacent to the concave inner wall of the outer tube; — whose concave inner wall is cylindrical; — and which, in its thickness, includes at least one axial slot whose width increases progressively according to the direction of gas flow from back to front inside the inner tube so as, according to the direction of gas flow injected axially into the inner tube, to progressively increase the effective passage area inside the tubular mixer, thanks to which, by venturi effect, air is drawn in by the gas which is injected to produce the fuel air-gas mixture in the burner.

[0012] Thanks to such a design of the tubular mixer, it is possible to produce it very simply from two sections of complementary outer and inner coaxial metallic tubes, available commercially, and by proceeding, in a single step - preferably but not limited to the laser cutting technique - to a material removal operation for the creation of each axial slot.

[0013] According to other characteristics of the burner:

[0014] - each axial slot opens axially at the free front end of the inner tube; - each axial slot is laterally delimited by two opposite edges giving it a flared profile; - each axial slot is laterally delimited by two opposite straight edges giving it a "V" profile; - the inner tube has several axial slots which are distributed angularly around the axis of the inner tube; - said several axial slots are regularly distributed angularly around the axis of the inner tube; - each axial slot is made by laser cutting of the inner tube; - the burner has a one-piece bracket which carries the gas injector, which is connected to the rear end of the tubular mixer, and which is made by laser cutting; - an open upper face of said support is closed by a cap (28), and the support comprises at least one tubular section which includes a ring of outlet lights for the air-gas fuel mixture which are formed near an upper end edge of said tubular section and / or a ring of axial outlet slots for the air-gas fuel mixture which open axially into said upper end edge of said tubular section; - said axial outlet slots of the air-gas fuel mixture which open axially in said edge are closed axially by said cap; - each light and / or each axial exit slot is made by laser cutting; - the support comprises a plenum including a fuel-air-gas mixture distribution box to which the front end of the venturi-effect tubular mixer is connected; and a plurality of horizontal, blind, parallel tubular bodies, each comprising: — a free inlet end connected to the distribution box which is supplied with a fuel-air-gas mixture; — and at least a series of outlet ports for the fuel-air-gas mixture which are distributed along the tubular body; - each tubular body is surmounted by a horizontal protective plate which is offset upwards and extends above the outlet orifices of the air-gas fuel mixture; - each tubular body is surmounted by a stiffening plate, for example a horizontal plate which is mounted on the tubular body by a bayonet hook system. Brief description of the figures

[0015] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for an understanding of which reference should be made to the accompanying drawings in which:

[0016] [Fig-1] - [Fig.1] is a perspective view of an example of an embodiment of burner according to the invention;

[0017] [Fig.2] - [Fig.2] is a view - from another angle - in exploded perspective of the burner shown in [Fig.1];

[0018] [Fig.3] - [Fig.3] is a view from another perspective angle of the burner of the [Fig.2];

[0019] [Fig.4] - [Fig.4] is a perspective and cross-sectional view along a longitudinal plane and horizontal passing through the longitudinal axis of the outer and inner tubes of the burner of the [Fig.l];

[0020] [Fig. 5] - [Fig. 5] is a cross-sectional view through a longitudinal and vertical plane passing by the longitudinal axis of the outer and inner tubes of the burner of the [Fig.l];

[0021] [Fig.6] - [Fig.6] is a detailed exploded perspective view at a larger scale of the external and internal tubes of the burner of the [Fig.l];

[0022] [Fig.7A] - [Fig.7A] is a partial perspective view of the outer and inner tubes of the burner of [Fig.2] which are represented in section by the transverse and vertical plane 7A-7A of [Fig.5];

[0023] [Fig.7B] - [Fig.7B] is a view analogous to that of [Fig.7A]-7A on which the outer and inner tubes of the burner of [Fig.2] are represented in section by a transverse and vertical plane which is axially offset forwards relative to the cutting plane of [Fig.7A];

[0024] [Fig.7C] - [Fig.7C] is a view analogous to that of [Fig.7B] in which the outer and inner tubes of the burner of [Fig.2] are represented in section by a transverse and vertical plane which is axially offset forward with respect to the cutting plane of [Fig.7B];

[0025] [Fig.7D] - [Fig.7D] is a view analogous to that of [Fig.7C] in which the outer and inner tubes of the burner of [Fig.2] are represented in section by a transverse and vertical plane which is axially offset forward with respect to the cutting plane of [Fig.7C];

[0026] [Fig.7E] - [Fig.7E] is a view analogous to that of [Fig.7D] in which the outer and inner tubes of the burner of [Fig.2] are represented in section by a transverse and vertical plane which is axially offset forward with respect to the cutting plane of [Fig.7D];

[0027] [Fig.7F] - [Fig.7F] is a view analogous to that of [Fig.7E] on which the outer and inner tubes of the burner of [Fig.2] are represented in section by a transverse and vertical plane which is axially offset forwards relative to the cutting plane of [Fig.7E];

[0028] [Fig.8] - [Fig.8] is a partial perspective and cross-sectional view by a vertical longitudinal plane of an alternative embodiment of the support and the burner cap of [Fig.1]; [Fig.9] - [Fig.9] is a perspective view of another example of an embodiment of a burner according to the invention;

[0029] [Fig. 10] - [Fig. 10] is a perspective view from another angle and partially exploded of the burner of [Fig. 9]. Detailed description of the invention

[0030] For the description of the invention and the understanding of the claims, the vertical, longitudinal and transverse orientations according to the V, L, T frame indicated in the figures, whose longitudinal L and transverse T axes extend in a horizontal plane, will be adopted without limitation and without limiting reference to terrestrial gravity.

[0031] By convention, the longitudinal axis L is oriented from back to front parallel to the direction of gas flow.

[0032] In the description that follows, identical, similar or analogous elements will be designated by the same reference numerals.

[0033] Figures 1 to 3 show a burner 10 which, from rear to front along the longitudinal axis AL, comprises successively: - a gas injector 12 with its supply fitting 14; - a bracket 16 which carries the gas injector 12; - a rear ring 18 for fixing the outer tube 20 to the caliper 16; - the outer tube 20 and an inner tube 22 coaxial to the outer tube 20 along their common longitudinal axis AL; - a front ring 24 for fixing the outer tube 20 onto a burner support 26; - and the burner support 26 with its upper cap 28.

[0034] The stirrup 16 is made in one piece of sheet metal cut by laser from a section of tube.

[0035] The stirrup 16 has two parallel longitudinal arms 30 which connect to each other a rear transverse collar 32 and a front transverse collar 34.

[0036] The rear transverse collar 32 has a central hole 33 allowing the injector 12 to be fixed inside the caliper 16 by screwing its threaded rear end 13 into the front end 15 of the fitting 14.

[0037] The front transverse collar 34 has a central hole 35 allowing the rear ring 18 to be fixed to the caliper 16, for example by welding.

[0038] The outer tube 20 is here a cylindrical tube with a circular cross-section, the rear end 19 of which is here of reduced diameter, is designed to be mounted coaxially inside the rear ring 18 and to be fixed to it, for example by welding.

[0039] Similarly, the front end 21 is designed to be mounted coaxially inside the front ring 24 and fixed to it, for example by welding.

[0040] The support 26 comprises two coaxial tubular sections along the vertical axis AV, here of cylindrical tube with circular cross-section, of which an outer tubular section 36 of larger diameter and an inner tubular section 38 of smaller diameter.

[0041] Each tubular section 36, 38 is produced by laser cutting from a tube of corresponding dimensions.

[0042] The two coaxial tubular sections 36 and 38 are mounted coaxially and fixed to each other by an annular lower plate 40 which is also made of laser-cut sheet metal.

[0043] The plate 40 here includes a diametrical crossbar with a central hole 41 allowing the support 26 to be fixed on any corresponding support, for example by means of a bolt or a screw.

[0044] The two coaxial tubular sections 36 and 38 delimit between them an annular passage or channel 42 for the passage of the air-gas mixture through the support 26.

[0045] For this purpose, in the lower part, the outer tubular section 36 has a hole 44, made by laser cutting, allowing the front ring 24 to be fixed to the outer tubular section 36, for example by welding.

[0046] The annular space 26 is thus connected to the outer tube 20 and is supplied with mixture air-gas through the front ring 24 and the orifice 44.

[0047] The cap 28 ensures the "closure" of the upper end face of the annular space 42 at its upper end.

[0048] For this purpose, the hat 28 is in the form of an annular plate made by laser cutting.

[0049] For its positioning and retention on the upper end of the support 26, the annular cap 28 has external notches 27 and internal notches 29.

[0050] The outer notches 27 receive, where appropriate with a slightly tight fit, axial lugs 37 which extend vertically upwards from the upper axial end edge 46 of the outer tubular section 36.

[0051] The inner notches 29 receive, where appropriate with a slightly tight fit, axial lugs 39 which extend vertically upwards from the upper axial end edge 48 of the inner tubular section 38.

[0052] Here, the mounting and fixing of the hat 28 on the support 26 is thus of the type with tenons 37, 39 and mortises 27, 29.

[0053] To constitute outlet orifices for the air-gas mixture for the formation of corresponding flames, at the upper part of the support 26, the outer tubular section 36 here includes, by way of non-limitation, a series of axial slots 50 (Arranged angularly in a regular ring) which open axially into the upper edge 46 and which are closed by the cap 28.

[0054] As a further, but not limiting, means of providing other combustion orifices for the air-gas mixture for the formation of corresponding flames, at the upper part of the support 26, the inner tubular section 38 hereby includes, as a non-limiting provision, a series of axial slots 52 (Arranged angularly in a regular ring) which open axially into the upper edge 48 and which are closed by the cap 28.

[0055] The presence or absence of axial slots, their number and / or their distribution depend in particular on the heating power that one wishes to obtain.

[0056] As an alternative not shown, each gas outlet orifice may be constituted by a blind light - or hole - formed in the tubular section 36, 38 near the cap 28.

[0057] Each tubular section 36, 38 with its various functional parts (Fingers 37, fingers 39, orifice 44, slots 50, slots 52) is advantageously made by laser cutting.

[0058] In accordance with the main feature of the invention, the venturi-effect tubular mixer, which is supplied with gas and air at its rear axial end to constitute an air-gas mixer, is formed by the combination of tube 20, which constitutes an outer casing tube, and tube 22, which constitutes an inner tube. Venturi effect.

[0059] The design of the inner tube 22 is such that it allows its production in a simple and economical way by laser cutting of a tube or section of tube which is here cylindrical with a circular cross-section.

[0060] The dimensions of the two tubes are such that the inner tube 22 is received axially without play inside the outer tube 20.

[0061] The inner tube 22 is delimited by its convex cylindrical outer wall 54 which is adjacent to the concave cylindrical inner wall 58 of the outer tube 20.

[0062] The concave inner wall 56 of the inner tube 22 is cylindrical.

[0063] According to the direction of flow of the gas injected axially into the inner tube 22 - from back to front - and in such a way as to progressively increase the effective passage section inside the tubular mixer 20-22, the inner tube here comprises a series of three axial venturi-effect slots 60.

[0064] The three slots 60 are here regularly spaced at an angle of 120 degrees.

[0065] Each axial slot 60 is formed here in the entire thickness of the wall of the inner tube 22.

[0066] Each axial slot 60 opens axially at the free front end 23AV of the inner tube 22.

[0067] Each slot 60 is laterally delimited by two opposite edges 62 giving it a flared profile.

[0068] Each edge 62 is here straight and gives each slot a flared “V” shaped profile.

[0069] As can be seen for example [Fig.5] and in figures 7B to 7E, the "width" L of each axial slot 60 increases progressively along the direction of gas flow from back to front inside the inner tube 22.

[0070] Here, width L means the average distance, measured circumferentially in a transverse plane, separating the two opposite edges 62 of a slot 60.

[0071] As can be seen in particular in figures 1, 4 and 5, the rear free end section of the inner tube 22 projects axially rearward beyond the rear axial end of the outer tube 20.

[0072] At its rear axial end 23AR, the inner tube 22 here has three V-shaped profiled notches 64 which open into the rear axial end edge 23AR.

[0073] The role of these notches

[0074] The role of these notches is to create a progressive reduction in the passage cross-section to accelerate the gas flow exiting the injector, thereby creating a vacuum that draws outside air towards this passage. This is the beginning of the Venturi effect.

[0075] Depending on the power of the burner, this part can be adjusted by moving it closer or further to injector 12 to adjust the proportion of air that enters.

[0076]

[0077] According to the embodiment variant of the support and the burner cap shown in [Fig.8], only the outer tubular section 36 with the largest diameter has axial slots 46.

[0078] Many variations are possible without departing from the general framework of the definition of the invention.

[0079] For example, the tubes or tube sections 20, 22, 36, 38 are not necessarily of circular section but may be of square section, always made by laser cutting in corresponding tubes of corresponding square section.

[0080] We will now describe the other example of the realization of a burner shown in figures 9 and 10 which is more particularly adapted to so-called “barbecue” cooking.

[0081] In this example, the design of the assembly constituting the venturi effect tubular mixer according to the invention is identical to that which has been described with reference to figures 1 to 8 and analogous or identical elements and components are designated by the same numerical references.

[0082] The front end 21 is designed to be mounted coaxially inside a front ring 24, and to be fixed to it for example by welding, which here belongs to a tubular elbow 70 at a right angle whose downstream section 72 extends vertically.

[0083] The support 26 here includes a plenum 74 for distributing the air-gas fuel mixture to which the front end of the venturi-effect tubular mixer is connected.

[0084] For this purpose, the plenum 74 comprises a horizontal housing 76 of rectangular parallelepiped shape which extends horizontally and which has an inlet orifice 78 formed in its lower wall 79 and to which the downstream section 72 of the elbow 70 is connected and fixed, for example by welding.

[0085] The housing 76 is made from a steel tube of corresponding cross-section.

[0086] In one 80 of its two vertical side walls, the case 76 comprises a series outlet ports 82 (here five in number) which are regularly distributed along the wall 80.

[0087] The plenum 74 has the function, through the outlet ports 82, of distributing the air-gas fuel mixture into a plurality of horizontal parallel and blind tubular bodies 84, each of which constitutes a tubular burner and has a free inlet end 86 which is connected to an outlet port 82 of the housing 76 to which it is fixed, for example by welding.

[0088] Each tubular body 84 has, here along its entire length, two parallel series of outlets 88 for the combustible air-gas mixture - for the formation of corresponding flames - which are here regularly distributed along the tubular body 84.

[0089] Each series of orifices 88 is laterally offset with respect to a median vertical plane of the tubular body 84.

[0090] In order to protect the outlet ports 88 and prevent them from being blocked, for example, by cooking residues, each tubular body 84 is surmounted by a horizontal protective plate 90 which is offset upwards and which extends above the outlet ports 88 of the air-gas fuel mixture.

[0091] Each protective plate 90 is mounted and fixed in a removable manner on the associated tubular body 84 by means of a mounting bar 92.

[0092] Each bar 92 is fixed to the upper part of the tubular body 84, here by welding, and it extends in the median vertical plane.

[0093] In its upper edge 94, each bar has a series of hooks 96 which is suitable to be received in a complementary notch 98 formed in the protective plate 90, to allow a reliable "bayonet" type assembly.

[0094] Furthermore, the protective plate 90 thus hooked onto the mounting bracket 92 contributes to the rigidification of the associated tubular burner body 84

Claims

Demands

1. A burner (10) for a gas stove or cooker comprising a gas injector (12) which is connected to a rear end of a venturi-effect tubular mixer (20, 22) whose front end is connected to a support (26), characterized in that the tubular mixer comprises: - an outer casing tube (20) having an internal cylindrical cross-section; - and an inner venturi-effect tube (22) coaxial with the outer tube (20); - which is adjacent to the concave inner wall (58) of the outer tube (20); - whose concave inner wall (56) is cylindrical;— and which, in its thickness, includes at least one axial slot (60) whose width (L) increases progressively according to the direction of gas flow from back to front inside the inner tube (22) so as, according to the direction of flow of the gas injected axially into the inner tube (22), to progressively increase the effective passage section inside the tubular mixer (20, 22), by which means, by venturi effect, air is drawn in by the gas which is injected to produce the air-gas fuel mixture in the burner (10).;

2. Burner (10) according to claim 1, characterized in that each axial slot (60) opens axially at the front free end (23A) of the inner tube (22).

3. Burner (10) according to any one of the preceding claims, characterized in that each axial slot (60) is laterally delimited by two opposing edges (62) giving it a flared profile.

4. Burner (10) according to the preceding claim, characterized in that each axial slot (60) is laterally delimited by two opposite straight edges (62) giving it a “V” profile.

5. Burner (10) according to any one of the preceding claims, characterized in that the inner tube (22) has several axial slots (60) which are distributed angularly around the axis (AL) of the inner tube (22).

6. Burner (10) according to the preceding claim, characterized in that said several axial slots (60) are regularly distributed angularly around the axis (AL) of the inner tube (22).

7. Burner (10) according to any one of the preceding claims, characterized in that each axial slot (60) is made by cutting inner tube laser (22).

8. Burner (10) any one of the preceding claims, characterized in that it comprises a one-piece yoke (16) which carries the gas injector (12), which is connected to the rear end of the venturi-effect tubular mixer (20, 22), and which is produced by laser cutting.

9. Burner (10) any one of the preceding claims, characterized in that an open upper face of said support (26) is closed by a cap (28), and in that the support (26) comprises at least one tubular section (36, 38) which has a ring of outlet lights for the air-gas fuel mixture which are formed near an upper end edge (46, 48) of said tubular section and / or a ring of axial outlet slots (50, 52) for the air-gas fuel mixture which open axially into said upper end edge (46, 48) of said tubular section (36, 38).

10. Burner (10) according to the preceding claim, characterized in that said axial slots (50, 52) for the outlet of the air-gas fuel mixture which open axially into said edge are closed axially by said cap (28).

11. Burner (10) according to any one of claims 9 or 10, characterized in that each light and / or each outlet slot is made by laser cutting.

12. Burner according to any one of claims 1 to 8, characterized in that said support comprises: - a plenum (74) comprising a housing (76) for distributing the air-gas fuel mixture to which is connected the front end (21) of the venturi effect tubular mixer (20, 22); - and a plurality of horizontal parallel blind tubular bodies (84) each comprising: — a free inlet end (86) connected to the distribution housing (76) which is supplied with air-gas fuel mixture; — and at least one series of outlet orifices (88) for the air-gas fuel mixture which are distributed along the tubular body (84).

13. Burner according to the preceding claim, characterized in that each tubular body (84) is surmounted by a horizontal protective plate (90) which is offset upwards and which extends over the outlet orifices (88) of the air-gas fuel mixture.

14. Burner according to claim 12, characterized in that each tubular body (84) is surmounted by a horizontal plate (90) of rigidity- fication.