[0001] The present invention relates to an improved gas burner.
[0002] Currently, market requirements are increasingly aimed at producing burners with several
flame rings, combined with the ever increasing requirement of reducing production
costs of such burners.
[0003] Burners with several flame rings of the so-called multi-ring type are known, provided
with a single gas inlet controlled by a standard single-exit valve. In particular,
the valve enables the gas to be fed to the burner inlet and from there simultaneously
to all the flame rings, of both maximum and minimum capacity.
[0004] Burners with several flame rings of the so-called dual type are also known, which
present two gas inlets, one associated with the burner outer portion, usually of annular
shape, and the other associated with its central inner portion of circular shape.
In particular, this type of burner uses a special two-way valve, enabling two operative
conditions: one of maximum power, in which both the burner portions are fed, and one
in which the outer annular portion is not fed, so enabling more modular use and allowing
a very low minimum power to be delivered.
[0005] In particular, from
IT 1232887 a multi-ring burner is known which uses primary air and secondary air both originating
from above the cooking hob. In particular, it presents three cup-shaped closed chambers,
each of which houses an injector; in greater detail, the injector positioned in the
central cup feeds the circular central portion with gas, while the two lateral injectors
each feed an outer portion of substantially half-moon shape.
[0006] In the central portion, mixing takes place by virtue of a venturi conduit of essentially
radial type, i.e. with a gas and primary air feed conduit which open into a radially
extending mixing chamber.
[0007] The two outer portions are instead fed by venturi conduits, each of which is formed
by a vertical conduit which widens from the bottom upwards and creates a venturi effect
by interaction with a dome-shaped projection provided in the lower face of the flame
divider. In greater detail, this projection is inserted in the top of the vertical
conduit such that the lower face of this projection and the upper terminal part of
this conduit define a narrow passage causing the mixture to accelerate, giving rise
to the venturi effect. Consequently, the two venturi conduits which feed the outer
portions are also of substantially radial type, mixture acceleration taking place
by virtue of the combination of a vertical conduit merging into a horizontal half-moon
shaped chamber.
[0008] A first drawback of this solution is its particularly high production cost; in particular
the dome projection provided in the lower face of the flame divider cannot be formed
by the normal sheet metal cold-pressing process used for producing nearly all burners,
but instead requires cast-iron casting or steel sintering processes, which are much
more costly.
[0009] Another drawback derives from the half-moon shape of the outer chamber portions.
In particular, the chambers internally present a portion which re-enters to define
a substantially elliptical space between them and the central portion. However, this
shape does not enable the outer annular portion to generate an inwardly-directed annular
ring of flames. The result is that this type of burner has only two flame rings, one
on the outer annular portion and one on the central portion, whereas the market mainly
requires burners with three flame rings, one on the central portion and two on the
annular portion, one directed outward arid one directed inward.
[0010] WO2004/044490 describes a multi-ring burner fed with primary air and secondary air both totally
drawn from above the cooking hob.
[0011] In particular, it presents three separate cup-shaped chambers, each of which houses
an injector. In greater detail, the central injector feeds the central portion of
the burner via a radial venturi, while the other two lateral injectors feed the outer
annular portion of the burner via two venturis of radial type such as those described
in
IT 1232887. As already stated, this type of venturi requires its horizontal chamber to have
rather large dimensions, and presents an internal diameter widening in that zone into
which said radial venturis flow; in other words, the annular portion is of unusual
and irregular shape.
[0012] Moreover the vertical conduits of this burner are cylindrical, do not present any
converging and/or diverging portions and do not cause any vertical venturi effect.
In greater detail, at their outlet, the vertical lateral conduits present a constriction
which then passes into a zone having a significant radial extension; the combination
of these characteristics defines a venturi of radial effect.
[0013] This type of burner presents a third ring of flames which emerge from the annular
portion and are directed inward; however said flames are distributed along an irregular
annular profile. Because of this, traditional inexpensive closure covers of regular
annular shape cannot be used to upperly close the chamber defined by the irregular
annular portion.
[0014] Consequently, this solution is particularly costly and characterised by a particular
non-traditional appearance little liked by cooking hob manufacturers.
[0015] WO2005/078342 describes a multi-ring burner also fed with primary and secondary air both drawn
from above the cooking hob. It is composed of a single cup closed at its bottom and
housing three injectors, in which the central injector is disposed vertically and
feeds the central portion with gas, while the other two lateral injectors are inclined
outward. The flame divider body is formed in two parts which when connected together
define two inclined conduits of venturi effect facing said lateral injectors.
[0016] This solution enables the annular portion to be of regular shape; however, the fact
that the flame divider body is made in two parts to form the two inclined venturi
conduits makes the burner production cost particularly high.
[0017] Moreover, the fact that the outer injectors are inclined creates a problem both during
production, assembly and burner leakage control, and along the production line where
the burner is mounting on the cooking hob, as specific suitable equipment is required.
[0018] US 2011/151385 describes a burner having the features specified in the preamble of claim 1. This
burner comprises a support body to be fixed to the lower surface of the cooking hob
sheet metal; it is provided with three injectors facing three conduits defined in
the flame divider. Inside the flame divider at the exit of the vertical venturi, barriers
are provided to prevent flame separation phenomena. The outer edges of the flame divider
body rest on the cooking hob sheet metal. In the light of all these characteristics,
it is particularly complicated both to produce and to mount.
[0019] US 2010/279238 describes a burner comprising a support body provided with three injectors facing
three vertical venturi conduits defined in the flame divider. In particular, the lateral
vertical venturi conduits are rather lengthy, hence the burner is particularly tall
and bulky in height. Moreover, in the light of the numerous components required, it
is particularly complicated constructionally and hence costly.
[0020] An object of the invention is to eliminate the drawbacks of the known solutions by
providing an improved three flame-ring gas burner which can operate both as a multi-ring
and as a dual burner.
[0021] Another object of the invention is to provide an improved gas burner, the flames
of which are not disturbed by sudden opening of an oven or unit door positioned below
the cooking hob.
[0022] Another object of the invention is to provide an improved gas burner of reduced overall
height.
[0023] Another object of the invention is to provide an improved gas burner of simple, rapid
and low-cost construction.
[0024] All these objects which will be apparent from the ensuing description are attained
according to the invention by an improved gas burner with the characteristics indicated
in claim 1.
[0025] Two preferred embodiments of the invention are further clarified hereinafter with
reference to the accompanying drawings, in which:
Figure 1 is a vertical section through a first embodiment of the improved gas burner
according to the invention,
Figure 2 is a vertical section therethrough perpendicular to that of Figure 1,
Figure 3 shows it in plan view under maximum flow conditions,
Figure 4 is a plan view of the injector holder of the burner of Figure 1,
Figure 5 is a vertical section through a first embodiment of the improved gas burner
according to the invention,
Figure 6 is a vertical section therethrough perpendicular to that of Figure 5.
[0026] As can be seen from Figures from 1 to 4, the improved gas burner 2, according to
the invention, comprises an injector holder 4 provided with a gas inlet 6 associated
with a standard single-exit valve, not shown. In particular, these figures show a
burner according to the invention in the multi-ring version, i.e. in which all the
flame rings are fed by a single gas source and are regulated altogether in the same
manner.
[0027] On the base of the injector holder 4 a conduit 8 is provided which faces the gas
inlet 6 and extends along the diameter of said injector holder 4. In this latter,
cup-shaped depressed zones are also provided, i.e. closed both on their base and laterally,
and open upwards; in particular, a central cup 10 and two lateral cups 12 and 12'
are provided.
[0028] On the base of the central cup 10 a first injector 14 is provided, which is disposed
vertically and is in communication via the conduit 8 with the gas inlet 6. Instead,
on the base of the lateral cups 12 and 12' a second injector 16 and a third injector
18 are provided respectively, which are also disposed vertically and are in communication
via the conduit 8 with the gas inlet 6.
[0029] On its circumferential surface, the injector holder 4 presents a flange 20 provided
with widened zones in which seats 22 are provided, required to fix the injector holder
4 by screws to the upper sheet metal of a cooking hob, not shown.
[0030] On the injector holder 4 a flame divider 24 rests provided with appendices 26, which
facilitate positioning and centring of this latter relative to the injector holder.
[0031] The flame divider 24 presents a central portion 28 surrounded by an outer annular
portion 30; in particular, the bases of said portions are connected together by a
flange 32 forming the bottom of an annular cavity 34. In greater detail, the flame
divider 24 is supported by raised portions 36 and 38 defined on the injector holder
4 and consisting of the upper prolongations of the lateral walls respectively of the
two outer cups 12 and 12' and of the central cup 10. In this manner, between the flame
divider 24 and the injector holder 4, passages are defined for the air drawn from
above the cooking hob. In particular, first slots 40 are provided for entry of primary
air 41 into the two outer cups 12 and 12', and second slots 42 for entry of primary
air 43 into the central cup 10; in addition, between the bottom of the flame divider
24 and the injector holder 4, openings 44 are provided for entry of secondary air
45 into the annular cavity 34 for the central flame ring 80 and for the inner annular
flame ring 82. In particular, the openings 44 define connection passages between the
annular cavity 34 of the flame divider and the space surrounding the burner, above
the cooking hob.
[0032] The central portion 28 of the flame divider 24 is provided centrally with a through
vertical conduit 46 facing the injector 14 positioned in the central cup 10 and of
upwardly converging frusto-conical shape. It opens into a cylindrical distribution
chamber 48 of reduced height.
[0033] The outer annular portion 30 of the flame divider 24 is instead provided with two
conduits 50 which face the injectors 16 and 18 and enter an annular distribution chamber
52 provided in the annular portion itself.
[0034] The central portion 28 of the flame divider 24 is provided on its upper edge with
a plurality of first radial recesses 64, while the annular portion 30 is provided
with a plurality of second radial recesses 66 and 68, defined respectively at the
outer upper edge 70 and at the inner upper edge 72 of the annular distribution chamber
52.
[0035] A circular closure cover 74 is rested on the central portion 28 of the flame divider
24 and upperly defines the recesses 64, while an annular closure cover 76 is rested
on the annular portion 30 and upperly defines the recesses 66 and 68.
[0036] The upper end of the venturi conduits 50 projects and emerges from the base 53 of
the annular distribution chamber 52. This is particularly advantageous in that it
enables particularly lengthy vertical venturi conduits to be provided, in order to
achieve optimal mixing of gas and primary air, while at the same time enabling a reduced
overall height of the burner to be maintained. In addition to this aspect, it is also
advantageous in that the fact that the upper end of the venturi conduits 50 is positioned
at a level above the base 53 of the annular chamber 52 prevents any water which might
spill over from a pan during cooking from entering the annular chamber 52 and from
there arriving to obstruct the injector and/or enter the inner cavity of the cooking
hob, where it could damage electrical circuits or other components.
[0037] The lower end 60 of each conduit 50 is at a slightly higher level than the upper
edge 62 of the injector holder 4, this facilitating draw-in of primary air for mixing.
[0038] The two lateral conduits 50 are configured such that air and gas flow which leaves
them and enters the annular distribution chamber 52 is substantially already completely
mixed. In particular, at the outlet of each lateral conduit 50, the height of the
annular chamber 52 is greater than one half the radius of the lateral conduit 50 at
its upper end.
[0039] In greater detail, each conduit 50 presents in sequence a convergent lower frusto-conical
portion 54 of diameter at its lower end substantially between 11 and 12 mm and serves
to convey the air and gas into a substantially cylindrical intermediate portion 56.
This has a diameter substantially between 8 and 9 mm and defines a constriction which
serves to accelerate the air/gas mixture; this mixture then opens into the divergent
upper frusto-conical portion 58, having an upper diameter substantially between 10
and 11 mm, which causes the mixture to expand.
[0040] Moreover, the distance between the upper end of the venturi conduits 50 and the lower
face of the annular cover 76 is substantially between 3 and 4 mm, preferably about
3.5 mm; essentially the passage between the outlet section of the venturi conduit
50 and the inlet section of the annular chamber 52 increases such that the mixture
continues to expand, without hindrance, within the annular chamber itself.
[0041] Advantageously, the flame divider 24 is provided with centring fins 78 in order to
enable unique positioning of the annular cover 76 relative to the annular portion
30 of the flame divider.
[0042] The operation of the burner according to the invention derives from the aforegoing
description.
[0043] When in its operative state, the burner single-exit control valve, not shown, is
open and consequently the gas reaches the three injectors 14, 16 and 18.
[0044] The gas leaving the injector 14 draws in, from the top of the cooking hob, a flow
of primary air 43 which passes through the slots 42 to enter the central cup 10 and
from there is drawn along the frusto-conical vertical conduit 46 causing the air and
gas to mix. In particular, when the air and gas flow reaches the distribution chamber
48 their mixing is already complete; the mixture thus formed then leaves the central
portion 28 through the radial recesses 64 to generate a central flame ring 80.
[0045] Instead, the gas that leaves the injectors 16 and 18 draws in, from the top of the
cooking hob, a flow of primary air 41 which passes through the passages 40 to enter
the respective cups 12 and 12' and from there is drawn along the conduits 50, to mix
with the gas. Again in this case, when the gas and primary air flow leaves the upper
end of the venturi conduits 50 and enters the annular distribution chamber 52, their
mixing is already substantially complete; the mixture formed in this manner then leaves
the annular portion 30 both through the internal radial recesses 72, to generate an
annular ring of inwardly directed flames 82, and through the outer radial recesses
70, to generate an annular ring of outwardly directed flames 84.
[0046] The secondary air 45 for igniting and maintaining the flames which form the central
ring 80 and the inner annular ring 82 originates from the top of the cooking hob and
enters the annular cavity 34 through the openings 44, while the secondary air for
igniting and maintaining the flames which form the outer annular ring 84 originates
from the environment surrounding the burner 2.
[0047] The embodiment shown in Figures 5 and 6 represents an improved gas burner 86 according
to the invention in the dual version, i.e. in the version with the flame rings fed
separately by two gas sources which are regulated independently.
[0048] It comprises all the characteristics previously described with reference to the embodiment
shown in Figures from 1 to 4, with the exception of the fact that an injector holder
88 is provided comprising two gas inlets 90, 92 with which a traditional two-exit
valve is associated (dual).
[0049] In particular, in the burner 86 illustrated in the embodiment of Figures 5 and 6,
the upper end of the venturi conduits 50 projects and emerges from the base 53 of
the annular distribution chamber 52. Moreover, again in the burner 86 the two lateral
conduits 50 are configured such that the air and gas flow, which emerges therefrom
and enters the annular distribution chamber 52, is substantially already completely
mixed. In particular, again in the burner 86, at the outlet of the lateral conduit
50, the height of the annular chamber 52 is greater than one half the radius of the
lateral conduit 50 at its upper end.
[0050] Essentially, that already stated relative to the configuration and to the dimensions
of the lateral conduit 50, and for the distance between the upper end of these and
for the lower surface of the outer annular cover 76 is also valid for the burner 86.
[0051] The burner 86 presents a first gas inlet 90 facing a first conduit 94 communicating
with the lateral injectors 16 and 18, and a second gas inlet 92 facing a second conduit
96 communicating with the central injector 14. In greater detail, the first conduit
94 extends along the diameter of said injector holder 88, while the second conduit
96 has a length substantially equal to one half of said diameter and is disposed perpendicularly
to and at a level slightly above the first conduit 94.
[0052] The operation of the burner shown in Figures 5 and 6 is identical to that already
described, with the difference that this burner when in its operative configuration
can assume two conditions. In particular, when the two-exit valve causes gas to flow
to both the inlets 90 and 92 there is a condition of maximum flow in which all three
injectors 14, 16 and 18 are fed in order to generate simultaneously all three flame
rings 82, 84 and 86. In contrast, when the inlet valve causes the gas to flow to just
the inlet 92 there is a minimum flow condition in which only the central injector
6 of the central cup 10 is fed in order to generate only the central flame ring 80.
[0053] In a variant valid for both the aforedescribed and illustrated embodiments, the annular
portion 30 could also not present inner radial recesses 72; in that case there would
be no annular ring of inwardly direct flames 82, and there would be only two flame
rings, namely the central flame ring 80 and the annular flame ring 84 with flames
directed outward.
[0054] From that stated it is apparent that the improved gas burner according to the invention
is more advantageous than traditional burners, in that:
- as it is composed of only four parts (injector holder, flame divider and two closure
covers) it is quick and particularly cheap to produce; in particular, the fact that
the flame divider is formed in a single piece, and the fact that the closure cover
of the annular portion is produced by cold pressing sheet metal, contribute to reducing
the overall burner production costs,
- the primary air is totally drawn from the top of the cooking hob,
- between the central portion and the outer annular portion an annular cavity is defined
such as to enable an annular ring of inner flames of regular shaped to be generated,
- the upper prolongation of the venturi conduits beyond the base of the annular chamber
increases the length and hence the efficiency of the venturi conduits, without increasing
the overall vertical height of the burner, and in addition eliminates the possible
negative effects on the injectors and on the space below the cooking hob, due to possibly
liquid spillage from a pan during cooking.
1. An improved gas burner (2, 86) comprising:
- an injector holder (4, 88) provided with means (20, 22) suitable for its installation
in the upper sheet metal of a cooking hob, and comprising a cup-shaped central cavity
(10), to the base of which a central injector (14) is applied, and further comprising
two lateral cup-shaped cavities (12, 12'), to the base of which two lateral injectors
(16, 18) are applied,
- at least one gas inlet (6) provided in said injector holder (4, 88) and connected
to said injectors (14, 16, 18),
- a flame divider (24) resting on the injector holder (4, 88) and defining a central
distribution chamber (48) provided in its substantially cylindrical lateral wall with
apertures (64) for generating a central ring of flames (80), and an annular distribution
chamber (52) which is separated from said central distribution chamber (48) by an
annular cavity (34) and is provided in its outer lateral wall with apertures (66)
for generating a ring of outwardly directed flames (84),
- a circular closure cover (74) for said central distribution chamber (48) and an
annular closure cover (76) for said annular distribution chamber (52),
- at least one connection passage between the space surrounding the burner (44) and
said annular cavity (34) of the flame divider (24),
- wherein the annular chamber (52) of the flame divider (24) incorporates two lateral
conduits (50) which:
- are disposed with their axis substantially vertical,
- have their lower ends facing said lateral injectors (16, 18), and
- are configured such as to generate an essentially vertical venturi effect, and such
that the gas and air flow emerging therefrom and entering the annular distribution
chamber (52) is substantially already completely mixed, characterised in that
- said cup-shaped cavities (10, 12, 12') are closed both on their base and laterally
while they are opened upwards,
- said lower ends (60) of the two lateral conduits (50) are disposed slightly higher
level than the upper edge (62) of the injector holder (4, 88), and
- said two lateral conduits (50) present an upper end portion which projects and emerges
from the base (53) of the annular distribution chamber (52).
2. A burner as claimed in one or more of the preceding claims, characterised in that at the outlet of the two lateral conduits (50) within the annular distribution chamber
(52), the height of the annular distribution chamber (52) is greater than one half
the radius of said lateral conduits (50) at their upper outlet end.
3. A burner as claimed in one or more of the preceding claims, characterised in that said annular distribution chamber (52) is provided in its inner lateral walls with
apertures (68) for generating a further ring of inwardly directed flames (82).
4. A burner as claimed in one or more of the preceding claims, characterised in that each of the lateral conduits (50) of the annular portion comprises a converging frusto-conical
lower portion (54) and a diverging frusto-conical upper portion (58).
5. A burner as claimed in one or more of the preceding claims, characterised in that each of the lateral conduits (50) of the annular portion also comprises a substantially
cylindrical intermediate portion (56).
6. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (24) defines, with said injector holder (4, 88), passages (40,
42) for conveying the primary air (43) originating from above the cooking hob, on
which said burner is intended to be installed, into said central cup-shaped cavity
(10) and into said lateral cup-shaped cavities (12, 12').
7. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (24) defines, with said injector holder (4, 88), at least one
passage (44) for conveying the secondary air (45) originating from above the cooking
hob, on which said burner is intended to be installed, and intended to feed the central
flame ring (80) and the inner annular flame ring (82).
8. A burner as claimed in one or more of the preceding claims, characterised in that at least one from said circular cover (74) and said annular cover (76) are made by
cold-pressing sheet metal.
9. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (24) comprises centring elements (78) for uniquely positioning
the annular cover (76) relative to the annular portion (30) of the flame divider.
10. A burner as claimed in one or more of the preceding claims, characterised in that said flame divider (24) comprises centring elements (78) for its unique positioning
relative to the injector holder (4, 88).
11. A burner as claimed in one or more of the preceding claims, characterised by comprising a single gas inlet (6) connected to the injector (14) of the central cup-shaped
cavity (10) and to the injectors (16, 18) of the lateral cup-shaped cavities (12,
12').
12. A burner as claimed in one or more of claims from 1 to 10, characterised in that the injector (14) of the central cup-shaped cavity (10) is connected to a first gas
inlet (92) while the injectors (16, 18) of the lateral cup-shaped cavities (12, 12')
are connected to a second gas inlet (90).
13. A burner as claimed in one or more of the preceding claims, characterised in that the flame divider (24) is supported by the walls of the central cup-shaped cavity
(10) and by the walls of the lateral cup-shaped cavities (12, 12') of the injector
holder (4, 88).
1. Verbesserter Gasbrenner (2, 86), umfassend:
- einen Einspritzdüsenhalter (4, 88), der mit Mitteln (20, 22) ausgestattet ist, die
zum Einbau im oberen Blech eines Kochfelds geeignet sind, und umfassend einen becherförmigen
zentralen Hohlraum (10) an dessen Basis eine zentrale Einspritzdüse (14) angelegt
wird, und ferner umfassend zwei seitliche becherförmige Hohlräume (12, 12'), an deren
Basis zwei seitliche Einspritzdüsen (16, 18) angelegt werden,
- wenigstens einen Gaseinlass (6), der in dem Einspritzdüsenhalter (4, 88) vorgesehen
und mit den Einspritzdüsen (14, 16, 18) verbunden ist,
- einen Flammenteiler (24), der auf dem Einspritzdüsenhalter (4, 88) ruht und eine
zentrale Verteilungskammer (48), die in ihrer im Wesentlichen zylinderförmigen Seitenwand
mit Öffnungen (64) zur Erzeugung eines zentralen Flammenrings (80) ausgestattet ist,
und eine ringförmige Verteilungskammer (52) definiert, die von der zentralen Verteilungskammer
(48) durch einen ringförmigen Hohlraum (34) getrennt ist und in ihrer äußeren Seitenwand
mit Öffnungen (66) zur Erzeugung einer Rings von nach außen gerichteten Flammen (84)
ausgestattet ist,
- eine kreisförmige Verschlussabdeckung (74) für die zentrale Verteilungskammer (48)
und eine ringförmige Verschlussabdeckung (76) für die ringförmige Verteilungskammer
(52),
- wenigstens einen Verbindungsgang zwischen dem Raum um den Brenner (44) und dem ringförmigen
Hohlraum (34) des Flammenteilers (24),
- wobei die ringförmige Kammer (52) des Flammenteilers (24) zwei seitliche Leitungen
(50) aufweist:
- die mit ihrer Achse im Wesentlichen vertikal angeordnet sind,
- deren untere Enden zu den seitlichen Einspritzdüsen (16, 18) weisen, und
- die dahingehend ausgelegt sind, dass ein im Wesentlicher vertikaler Venturi-Effekt
erzeugt wird, und dass die davon ausströmende und in die ringförmige Verteilungskammer
(52) eintretende Gas- und Luftströmung im Wesentlichen bereits vollständig vermischt
ist,
dadurch gekennzeichnet, dass
- die becherförmigen Hohlräume (10, 12, 12') sowohl an ihrer Basis als auch seitlich
geschlossen sind, während sie nach oben offen sind,
- die unteren Enden (60) der zwei seitlichen Leitungen (50) etwas höher angeordnet
sind als der obere Rand (62) des Einspritzdüsenhalters (4, 88), und
- die zwei seitlichen Leitungen (50) einen oberen Endabschnitt präsentieren, der hervorsteht
und von der Basis (53) der ringförmigen Verteilungskammer (52) hervortritt.
2. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass am Auslass der zwei seitlichen Leitungen (50) in der ringförmigen Verteilungskammer
(52) die Höhe der ringförmigen Verteilungskammer (52) größer als der halbe Radius
der seitlichen Leitungen (50) an ihrem oberen Auslassende ist.
3. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die ringförmige Verteilungskammer (52) in ihren inneren Seitenwänden mit Öffnungen
(68) zur Erzeugung eines weiteren Rings von nach innen gerichteten Flammen (82) ausgestattet
ist.
4. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass jede der seitlichen Leitungen (50) des ringförmigen Abschnitts einen konvergierenden
kegelstumpfförmigen unteren Abschnitt (54) und einen divergierenden kegelstumpfförmigen
oberen Abschnitt (58) umfasst.
5. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass jede der seitlichen Leitungen (50) des ringförmigen Abschnitts auch einen im Wesentlichen
zylindrischen Zwischenabschnitt (56) umfasst.
6. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Flammenteiler (24) mit dem Einspritzdüsenhalter (4, 88) Durchgänge (40, 42) zur
Leitung der primären Luft (43), die von oberhalb des Kochfelds stammt, auf dem der
Brenner eingebaut werden soll, in den zentralen becherförmigen Hohlraum (10) und in
die seitlichen becherförmigen Hohlräume (12, 12') definiert.
7. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Flammenteiler (24) mit dem Einspritzdüsenhalter (4, 88) wenigstens einen Durchgang
(44) zur Leitung der sekundären Luft (45), die von oberhalb Kochfelds stammt, auf
dem der Brenner eingebaut werden soll, und die den zentralen Flammenring (80) und
den inneren ringförmigen Flammenring (82) speisen soll, definiert.
8. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass wenigstens die kreisförmige Abdeckung (74) und/oder die ringförmige Abdeckung (76)
durch Kaltpressen von Blech gefertigt werden.
9. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Flammenteiler (24) Zentrierelemente (78) zur eindeutigen Positionierung der ringförmigen
Abdeckung (76) bezüglich des ringförmigen Abschnitts (30) des Flammenteilers umfasst.
10. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Flammenteiler (24) Zentrierelemente (78) für seine eindeutige Positionierung
bezüglich des Einspritzdüsenhalters (4, 88) umfasst.
11. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass er einen einzelnen Gaseinlass (6) umfasst, der mit der Einspritzdüse (14) des zentralen
becherförmigen Hohlraums (10) und mit den Einspritzdüsen (16, 18) der seitlichen becherförmigen
Hohlräume (12, 12') verbunden ist.
12. Brenner nach einem oder mehreren der Ansprüche 1 bis 10, dadurch gekennzeichnet, dass die Einspritzdüse (14) des zentralen becherförmigen Hohlraums (10) mit einem ersten
Gaseinlass (92) verbunden ist, während die Einspritzdüsen (16, 18) der seitlichen
becherförmigen Hohlräume (12, 12') mit einem zweiten Gaseinlass (90) verbunden sind.
13. Brenner nach einem oder mehreren der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der Flammenteiler (24) von den Wänden des zentralen becherförmigen Hohlraums (10)
und von den Wänden der seitlichen becherförmigen Hohlräume (12, 12') des Einspritzdüsenhalters
(4, 88) gestützt wird.
1. Brûleur à gaz perfectionné (2, 86), comprenant:
- un support d'injecteur (4, 88) pourvu de moyens (20, 22) appropriés pour son installation
dans la plaque métallique supérieure d'une table de cuisson, et comprenant une cavité
centrale en forme de coupe (10), à la base de laquelle un injecteur central (14) est
appliqué, et comprenant en outre deux cavités latérales en forme de coupe (12, 12'),
à la base desquelles deux injecteurs latéraux (16, 18) sont appliqués,
- au moins une entrée de gaz (6) prévue dans ledit support d'injecteur (4, 88) et
connectée auxdits injecteurs (14, 16, 18),
- un diviseur de flamme (24) reposant sur le support d'injecteur (4, 88) et définissant
une chambre de distribution centrale (48) comportant dans sa paroi latérale sensiblement
cylindrique des ouvertures (64) pour générer un anneau de flammes central (80), et
une chambre de distribution annulaire (52) qui est séparée de ladite chambre de distribution
centrale (48) par une cavité annulaire (34) et qui comporte dans sa paroi latérale
extérieure des ouvertures (66) pour générer un anneau de flammes orientées vers l'extérieur
(84),
- un capot de fermeture circulaire (74) pour ladite chambre de distribution centrale
(48), et un capot de fermeture annulaire (76) pour ladite chambre de distribution
annulaire (52),
- au moins un passage de connexion entre l'espace entourant le brûleur (44) et ladite
cavité annulaire (34) du diviseur de flamme (24),
- dans lequel la chambre annulaire (52) du diviseur de flamme (24) incorpore deux
conduits latéraux (50) qui:
- sont disposés avec leur axe sensiblement vertical,
- présentent leurs extrémités inférieures en face desdits injecteurs latéraux (16,
18), et
- sont configurés de manière générer un effet venturi essentiellement vertical, et
de telle sorte que l'écoulement de gaz et d'air qui en émerge et qui entre dans la
chambre de distribution annulaire (52) est sensiblement déjà complètement mélangé,
caractérisé en ce que:
- lesdites cavités en forme de coupe (10, 12, 12') sont fermées à la fois à leur base
et latéralement lorsqu'elles sont ouvertes vers le haut,
- lesdites extrémités inférieures (60) des deux conduits latéraux (50) sont disposées
à un niveau légèrement plus haut que le bord supérieur (62) du support d'injecteur
(4, 88), et
- lesdits deux conduits latéraux (50) présentent une partie d'extrémité supérieure
qui fait saillie et émerge de la base (53) de la chambre de distribution annulaire
(52).
2. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce qu'à la sortie des deux conduits latéraux (50) à l'intérieur de la chambre de distribution
annulaire (52), la hauteur de la chambre de distribution annulaire (52) est plus grande
que la moitié du rayon desdits conduits latéraux (50) à leur extrémité de sortie supérieure.
3. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que ladite chambre de distribution annulaire (52) comporte dans ses parois latérales
intérieures des ouvertures (68) servant à générer un anneau supplémentaire de flammes
orientées vers l'intérieur (82).
4. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que chacun des conduits latéraux (50) de la partie annulaire comprend une partie inférieure
tronconique convergente (54) et une partie supérieure tronconique divergente (58).
5. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que chacun des conduits latéraux (50) de la partie annulaire comprend également une partie
intermédiaire sensiblement cylindrique (56).
6. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que ledit diviseur de flamme (24) définit, avec ledit support d'injecteur (4, 88), des
passages (40, 42) pour transporter l'air primaire (43) provenant du dessus de la table
de cuisson, sur laquelle ledit brûleur est destiné à être installé, dans ladite cavité
centrale en forme de coupe (10) et dans lesdites cavités latérales en forme de coupe
(12, 12').
7. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que ledit diviseur de flamme (24) définit, avec ledit support d'injecteur (4, 88), au
moins un passage (44) pour transporter l'air secondaire (45) provenant du dessus de
la table de cuisson, sur laquelle ledit brûleur est destiné à être installé, et destiné
à produire l'anneau de flammes central (80) et l'anneau de flammes annulaire intérieur
(82).
8. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce qu'au moins un parmi ledit capot circulaire (74) et ledit capot annulaire (76) est formé
par pressage à froid d'une plaque de métal.
9. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que ledit diviseur de flamme (24) comprend des éléments de centrage (78) pour positionner
uniquement le capot annulaire (76) par rapport à la partie annulaire (30) du diviseur
de flamme.
10. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que le diviseur de flamme (24) comprend des éléments de centrage (78) pour son positionnement
unique par rapport au support d'injecteur (4, 88).
11. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce qu'il comporte une seule entrée de gaz (6) connectée à l'injecteur (14) de la cavité
centrale en forme de coupe (10) et aux injecteurs (16, 18) des cavités latérales en
forme de coupe (12, 12').
12. Brûleur selon une ou plusieurs des revendications 1 à 10, caractérisé en ce que l'injecteur (14) de la cavité centrale en forme de coupe (10) est connectée à une
première entrée de gaz (92), alors que les injecteurs (16, 18) des cavités latérales
en forme de coupe (12, 12') sont connectées à une deuxième entrée de gaz (90).
13. Brûleur selon une ou plusieurs des revendications précédentes, caractérisé en ce que le diviseur de flamme (24) est supporté par les parois de la cavité centrale en forme
de coupe (10) et par les parois des cavités latérales en forme de coupe (12, 12')
du support d'injecteur (4, 88).