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Патент USA US3070162

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Dec. 25, 1962
Original Filed Nov. 13, 1953
2 Sheets-Sheet 1
\ $4
Dec. 25, 1962
Original Filed_Nov. l3, lIgT3ERNAL
gw9l“I;Quvmw l
2 Sheets-Sheet 2
Qontinuation of application her. No.
1953. This application
24,‘ 15360,‘
7 tCiaims. (5C2, Edda-i115)
Patented Dec. 25, lS?Z
Thus, it is among the objects of the present invention
to provide a high-velocity ?ame pilot burner of the sparlc~
ignition type in which the electrode connection is made
outside the heating zone into which the pilot extends, and
the electrode itself extends internally of the pilot and is
.i, l‘slov. E3,
No. 17,339
effectively cooled by the air-gas mixture ?owing through
the pilot to the burner head thereof.
t is another object of the present invention to provide
a high-velocity ?ame pilot burner of the spark-ignition
type in which the aforementioned internal electrode in
his invention relates generally to spark-ignited pilot
burners, and more particularly to high-velocity flame pilot
burners with internal spark ignition.
the pilot extends into the high-velocity gas jet issuing
therefrom and the sparks from the electrode ignite this
higlnvelocity gas jet, thereby not only to enhance the cool—
This application is a continuation of my co-pending
application, Serial No. 391,845, ?led November 13, 1953,
now abandoned.
ing effect of the air-gas mixture on the electrode at its
High-velocity ?ames from utility burners as Well as
point not rest the ?ame, but also permit centralized loca
from pilot burners therefor are required to withstand air 15 tion of the electrode throughout the pilot for maximum
currents of considerable velocity which are intentionally
cooling effect by the internally ?owing air-gas mixture on
induced in bakery ovens and many other commercial heat
the entire electrode, as well as for endwise removal of
ing installations in order uniformly to distribute the
the electrode from, or its installation in, the pilot expedi
heated air throughout the heating zones involved. To
tiously and with the least difiiculty.
withstand these air currents it is necessary that the gases
It is a further object of the present invention to devise
issuing from the pilot burner have a high velocity, for the
a method of igniting the low-velocity gas jet or jets from
higher the‘ velocity of the pilot flame gases the more stable
the associated higlnvelocity ?ame immediately after the
the flame will be. it ias been customary in such appli
latter has been ignited by sparks from the aforementioned
cations to provide pilot burners in which the velocity of
internal electrode and before these sparks cease, thereby
the gases issuing therefrom approach or exceed the speed 25 to achieve support of the high-velocity ?ame from the
of ?ame propagation in the mixture as such ?ames are
low-velocity ?ame or ?ames without which the former
very stable and will withstand very strong air currents.
would extinguish as soon as the sparks cease.
However, when the velocity of the pilot ?ame gases reaches
Another object of the present invention is to provide
such high values then the flame is not self-sustaining be
in a high-velocity flame pilot burner of the spark-ignition
cause it travels at a slower speed than the burning gases.
type exceedingly simple structure which, in accordance
Accordingly, such ?ames will not remain lighted after the
with the aforementioned method, unfailingly brings about
initial ignition ceases. Some means, therefore, has to be
immediate ignition of the low-velocity gas jet or jets by
provided for continuously sustaining the pilot flame after
the initial spark ignition has ceased. These means have
customarily included secondary or low-velocity ?ames
adjacent the main high-velocity pilot ?ame. These low
velocity ?ames serve to continuously ignite the high-ve
locity flame. The low-velocity ?ames are self-sustaining
the spark-ignited high-velocity ?ame.
A further object of the present invention is to provide
in a high-velocity ?ame pilot burner of the aforemen
tioned spark-ignition type a quite substantial contact area
between the ?ame and the burner end of the pilot, thereby
to adapt the pilot to the recently developed flame recti
because their gas velocities are below the speed of ?ame 40 ?cation control according to which a control current is
propagation and, once the flame is ignited, it continues to
conducted from a ?ame rod through the ?ame to the pilot
burn thereafter. Accordingly, high-velocity ?ames and
and there grounded, and when this current is interrupted
the customary low~velocity supporting ?ames of pilot
at any time at the ?ame, through accidental extinction or
burners have heretofore been ignited by initially igniting,
undesired changes in the burning characteristics of the
with sparks, the readily ignitible low-velocity gas jets,
latter from any disturbing cause whatever, control instru
whereupon the ensuing low-velocity ?ames will with cer 45 ments will indicate this fact and the electrode will be
tainty ignite the closely proximate high-velocity gas jets
and support the ensuing high-velocity ?ames. All pre
vious attempts at spark-igniting the high-velocity gas jets
and relying on the ensuing high-velocity ?ames to ignite
the associated low-velocity gas jets have failed. In order
to accomplish initial spark-ignition of the low-velocity
gas jets, the spark-ignition is arranged externally of these
previous pilot burners with the electrodes located Within
charged and the sparks issuing therefrom will reignite the
pilot ?ame as soon as the disturbance is correct-ed or cor
rects itself, the current used in this ?ame recti?cation
control being of the order of a few microamperes and
these may, for safer and more reliable performance of
the control, be increased the more the larger the contact
area of the ?ame with the pilot is in proportion to the
?ame’s contact area with the ?ame rod.
spark-ignition proximity of the low-velocity gas jets.
Further objects and advantages will appear to those
However, this arrangement of th spark-ignition exter
skilled in the art from the following, considered in con
nally of the pilot burners has been found unsatisfactory
junction With the accompanying drawings.
due to the early deterioration of the electrodes themselves
In the accompanying drawings, in which certain modes
and of their customarily insulated connectors under the
of carrying out the present invention are shown for illus
intense heat to which they are constantly subjected in the
trative purposes:
heating zones for long periods at a time, and the frequent 60
FIG. 1 is a side view of a high-velocity ?ame pilot
replacement of electrodes and connectors necessitated by
burner embodying the internal spark ignition of the
their early deterioration.
present invention;
it is the primary object of the present invention to pro
FIG. 2 is a longitudinal section through the same pilot
vide a high-velocity flame pilot burner of the spark-igni
tion type in which the sparking electrode and the con
FIGS. 3, 4 and 5 are enlarged cross sections through
hector thereto are removed from the intense heat in the
the pilot burner as taken on the lines 3——3, 4-4 and 5-5,
zone into which the length of the pilot normally extends,
respectively, of FIG. 2; and
thereby to greatly increase the useful life of the electrode
FIG. 6 is a fragmentary section taken on the line 6—6
of FIG. 2.
and its connector beyond that of previous types, and thus
Referring to the drawings, and more particularly to
overcome the aforementioned serious de?ciency of pre 70
FIGS. 1 and 2 thereof, the reference numeral it) desig
vious spark-ignition pilot burners.
nates a pilot burner which comprises a burner body 12
grooves 82 in the holder (FIG. 2). The keys 39 may
with a burner tube extension 14, a burner head 15 and
spark ignition means 18. The burner body 12 and tube
14 provide a continuous passage 26, and the burner body
conveniently be swaged from the wire stock of which the
electrode 53 is formed. The electrode 53 is held against
axial movement in its holder 59 by stop lugs 34 which are
12. is furthermore provided with a lateral branch pas
sage 22 through which to conduct an air-gas mixture
under pressure into and through the passage
to the
by a termnial
burner head 16 for sustaining a high-velocity pilot ?ame
fthereat (H6. 6).
The instant pilot burner is adapted especially, though
not exclusively, for use with high-velocity liame utility
burners in bakery ovens or other heating installations hav
ing Zones of high heat-intensity in which powerful fans
uniformly distribute the heated air. A cordingly, the
pilot ?ame of the instant burner must have a high velocity
in order safely to withstand the considerable air cur
rents in these heating installations. Further, the instant
burner and more particularly the tube 14 thereof, must
be of considerable length in order that the burner be ac
cessible at the outside of a heating installation and extend
into igniting relation with a utility burner or burners in
the heating zone therein. To this end, the body 12 of the
held against a metal washer as in a recess 88 in the holder
that is threadedly received by the outer
end 92 of the electrode. Like the keys as, the stop lugs
are also conveniently swaged from the wire stock of
the electrode 53. Preferably interposed between the
terminal 599 and the adjacent end of the electrode holder
69 are washers 94 of which at least one is sufficiently
yielding to take up diiferentia expansion under heat of
the holder on and electrode 58. The terminal ‘,‘ii serves
as a connector for a conductor from any suitable elec
tric power source.
forward or spark end liiil of the electrode 5;‘; ex
tends into the burner port 56, terminating substantially
concentrically thereof closely adjacent the downstream
end or face of said high-velocity port, but must un er no
circumstances contact the wall of this burner port as this
would of course result in short‘circuiting of the electrode.
Since the electrode 58 is of considerable length as ex
instant burner is at one end threaded as at St} for its re
plained, and since its holder as is quite removed from
movable mounting in a suitable anchor plate 32 on the
the burner head in and may not with any certainty hold
the electrode from Contact with the wall of the burner
port 55, there is provided near the burner head 16 a
spacer Hi2 which is held on the electrode 58 by self
locking washers 1%. This spacer M32 is received in the
burner tube
with such slight clearance as to permit
the compressed air-gas mixture escaping through the
burner port 56 accurately to center the spark end 1% of
and the of
a heating
head 1%
thereon extending
with the into
the tube
zone of the installation.
One end of the burner tube 14 is conveniently threaded
at 34 for its removable mounting in the burner body l2‘,
While the burner head 16 is, through intermediation of a
nozzle 36, mounted on the other end of the burner tube
14. The nozzle 36, which serves for a purpose to be de
scribed hereinafter, is in this instance screwed at 38 onto
the adjacent end of .the burner tube 14, and is provided
intermediate its ends with a tapped hole 40 for the
the electrode therein, yet prevent contact of the later
with this port under any circumstances. The spacer hi2,
threaded reception of the body 44 of the burner head is.
star-shaped (H6. 5) so as not to impede the flow of the
air-gas mixture through the passage 21}.
Arranged in downstream relation with the electrode 53,
which is a sparking electrode, is a grounding electrode
which is arc-shaped and in this instance mounted
The body 44 of the burner head 16, which constitutes the
downstream end or terminus of the passage 2i), is pro
vided with a plurality of burner ports 46 (FIGS. 3 and 6)
which are preferably arranged concentrically about the
axis of the burner tube 14, and are in communication
with the passage 20 therein. The body 44 of the burner
head 16 is also provided with a shank 48 which at its for
ward end has an enlarged collar formation 5!} (FIGS. 2
and 6). The burner head in is provided with a central
recess 52 which in this instance holds an insert 54 hav
ing a central burner port 56 which is also in communica
tion with the passage 20 in the burner tube 14. The ar~
rangement of the ports in head 16 is such that the central
port 56 is surrounded by the ports 46 whose downstream
termini are located slightly upstream of the terminus of
the high-velocity port 56, for reasons which are explained
The spark ignition means 18 includes an electrode 53
which is in the form of a rod and is carried by a holder
60 of any suitable electric-insulating and heat-resistant
material, such as ceramic, for instance. The holder 6%),
being in the form of a sleeve in which the electrode 53
is received, is provided intermediate its ends with a
which is preferably made of a high heat-resistant ma
terial, such as ceramic, for instance, is in this instance
with both ends in the collar formation 58 on the burner
head 16 (FIG. 2). The electrode iii-"s is thus electrically
connected with the burner head 16 and burner tube 14
for grounding sparks emanating from the electrode 58
and jumping the spark gap g.
The air-gas mixture for the burner is formed in a mixer
N6 which in this instance consists of two complemental
parts 198 and it'll (FIG. 2). Conduits T12 and 114 serve
for the introduction of gas and compressed air, respec
tively, into a mixing chamber 116. Provided in the mixer
Hi6 in the path of the admitted compressed air is a con
stricted passage 113, followed a short distance therefrom
by an outlet tube 126 which through a ?tting 122 is in
communication with the branch passage 22 in the burner
body .112. The compressed air admitted through the con
stricted passage 118 has a su?iciently high velocity to
have a Venturi effect on the surrounding gas in the mix
ing chamber 116 and suck into the outlet tube 120 a suffi
cient amount of this gas to form therewith a highly
mounting collar 64', which through intermediation of 60 ?ammable mixture which for the sake of brevity is re
washers as, 68 and 76 is held against an internal shoulder
ferred to as “gas” throughout the rest of the speci?cation.
71 in the burner body 12 by means of a lock nut 72 (FIG.
Manual valves, one being shown at 124 in FIGS. 1 and
2). At least the collars 64 are preferably of relatively
2, are preferably provided to permit opening and closing
soft material to take up differential expansion under heat
of the gas and air conduits H2 and 114. The branch
of the burner body 12 and holder 69 without any adverse
passage 22 in the burner body 12 forms such a slight
effect on the latter. The lock nut '72 and the washer 70
angle with the main passage 20 therein (FIG. 2) that the
further serve to center the holder 6%) and, hence, also the
gas will have a practically unobstructed ?ow into the
electrode 58 in the passage 20, while the washers 63,
being preferably of copper, serve also to seal the rear end
latter and substantially maintain its velocity throughout
the burner.
in operation, gas from the mixer TM flows at con
siderable velocity through the passages 22 and 2% in the
burner body l2 and burner tube 14 to the burner head
The electrode 58 is received with a sliding ?t in the
16 where it escapes through the burner ports 55 and 46.
sleeve-like holder 66, but is held against rotation therein
The sparking electrode 58 may then be connected for a
by a key or keys 80 which project into longitudinal 75 brief interval with the electric power source for the pro
of the passage 24} against leakage of the air-gas mixture
therethrough. The electrode 58 is thus mounted in the
burner body 12 in electrically insulated fashion.
duction of sparks s (FIG. 6) some of which jump from
the sparking electrode 58 to the Wall 130 of the high
velocity port 56 and some of which jump the gap g to be
grounded through the grounding electrode 104. The
sparks s thus emanating from the electrode 58 ignite the
gas escaping from the burner ports 56 and 46. The ensu
advanced as to why the low-velocity gas: from the sec
ond'ary burner ports will ignite under these circumstances,
it is believed that that part of the lowevelocity gas m’
which is admitted into close proximity to the high~velocity
gas In is drawn into a partial vacuum created around
ing flame }‘ is of the high-velocity and high heat-intensity
the latter due to its high-velocity, and intermingles with
some of the high-velocity gas sufliciently to propagate
type and is composed of a high-velocity jet ?ame f’ of
the spark-ignited high-velocity ?ame f’ to the low-pressure
considerable length and a plurality of secondary or low
gas In’. Many expediencies suggest themselves to achieve
velocity ?ames 1”’ which support the high-velocity jet
?ame f’. The high-velocity jet ?ame j" emanates from
the ?ow of a part of the lovwvelocity gas in’ from the
secondary burner ports 46 into close proximity to the
high-velocity gas in from the main burner port 56 in
the central high~velocity burner port 5-6, while the low
the region within which the former is ignited by sparks
velocity ?ames f" emanate from the low-velocity burner
s from the electrode 53. Thus, the secondary burner
ports 46. As the high-velocity designation of the central
burner port 56 indicates, the gas m escaping therethrough 15 ports 46 may be arranged so closely to the main burner
port 55 that part of the low-velocity gas emerging from
(FIG. 6) has considerably higher velocity than the gas
the former will flow into close proximity to the high
In’ escaping through the l0w~velocity ports 46. This is
velocity gas emerging from the latter. In the present
due to the fact that despite the extension of the sparking
instance, the collar formation 5% on the burner head 16
electrode 58 into the central burner port 56 the clear
cross-sectional area of the latter is considerably larger 20 is at its front formed frusto-conical as at 132 so as to
permit the low-velocity gas In’ from the secondary burner
than that of any of the low-velocity burner ports 46.
ports 46 to expand into close proximity to the high
It is, of course, the internal arrangement of the spark
velocity gas In from the main burner port 56 as shown
ing electrode 58 in the instant pilot burner which achieves
in FIG. 6. Thus, it is the underlying method of directing
the aforementioned objective of lending to this electrode
‘and its connector a useful life which is incomparably long 25 a part of the low-velocity gas from the secondary ports
'46 into close proximity to the high-velocity gas from the
er than that of previous sparking electrodes and their
main burner port 56 which brings about assured and
connectors. Thus, the centralized location of the spark
instantaneous ignition of the high-velocity and low-veloc
ing electrode 58 in the instant burner results not only
ity components f’ and f" of the ?ame f by sparks entirely
in maximum spacing of the former from the heat-exposed
walls of the latter, but also in maximum cooling of this 30 within the con?nes of the high-velocity gas in and assured
maintenance of these ?ame components 3" and 1”’ after
electrode by the surrounding gas as it flows at consider
spark production by the electrode 58 has ceased.
able velocity through the burner. Moreover, and in
further distinct contrast to the connectors of previous
The beforementioned nozzle 36 is provided to achieve
sparking electrodes for pilot burners of this type, the
connector used for the instant sparking electrode is, by
virtue of the internal arrangement of the latter, connected
the aforementioned objective of ready adaptation of the
instant pilot burner to the recently developed ?ame recti
?cation control. To achieve the substantial grounding
with the electrode on the outside of the heating installa
tion and is, therefore not at all subjected to heat.
area between the ?ame and the burner required by this
?ame recti?cation control in order to permit, for safer
and more reliable performance of the control, the use
When no gas ?ows through the burner, all sparks
emanating from the electrode 58 will follow the path
of least resistance and jump the narrow gap between the
spark end 1% of this electrode and the wall 139 of the
insert 54- forrning the high-velocity burner port 56. How
ever, when gas In of any appreciable velocity, and espe
cially of the highJ/elocity contemplated, passes through
the burner port 56, substantially all sparke s emanating
of a current of a maximum number of microamperes,
the nozzle 35 has a cylindrical ?ame contact area 140 of’
considerable extent. The control current is by a flame
rod 142 (indicated in dot‘and-dash lines in FIG. 6) ap
plied to the ?ame j‘ which conducts this current to the
nozzle 36 where it is grounded. As shown in FIG. 6,
the collar formation 50 on the burner head 16 extends
from the electrode 50 will be blown by this gas against
into fairly close proximity to the cylindrical surface or
the grounding electrode tllltd in a path in more or less
?ame contact area 14d of the nozzle to form a somewhat
direct alignment with the electrode 58 (FIG. 6). How—
constricted annular passage 1% from which the emerging
ever, some sparks will still jump the narrow gap between 50 low-velocity gas in’ will in part ?ow from along this cylin
the electrode 58 and the Wall 130. Accordingly, the
drical nozzle surface and support the low-velocity ?ames
sparks s from the electrode 58 are thus kept more or less
f” in a disposition in which they sweep a maximum area
wholly within the con?nes of the high-velocity gas In
of this cylindrical nozzle surface. On the other hand,
that emerges from the burner port 56.
the frusto-conical formation of the front face 132 of the
Considerable dif?culty was encountered in igniting the 55 collar formation St) on the burner head 16 permits a
?ame ]‘ on brief production of sparks by the electrode 58
suflicient amount of the low-velocity gas in’ to expand
and thereafter sustaining the ?ame. Thus, while these
sparks partly ignited the high-veloicty gas In in the im
mediate vicinity of the burner port 56, they did not ignite
the low-velocity gas In’ emerging from the secondary
burner ports 46, with the result that the high-velocity
?ame f’ became extinguished immediately after the elec
trode ceased spark production. Hence, in order that the
high-velocity jet ?ame f’ may, after its spark ignition,
be maintained in the only way known, namely by the
secondary or low-velocity ?ames f", it became imperative
into close proximity to and be drawn into the high
velocity gas In near its emergence from the main burner
port 56 to achieve the aforementioned simultaneous
and m’
and 46
and f"
of the high-velocity and low-velocity gas jets in
from the main and secondary burner ports 56
on spark production by the electrode 58, and
maintenance of the ignited ?ame components f’
after spark production by the electrode 58 has
65 ceased.
secondary burner ports 46 simultaneously with the spark
The invention may be carried out in other speci?c ways
than those herein set forth without departing from the
spirit and essential characteristics of the invention, and
ignition of the high-velocity gas In from the main burner
port 56. After many trials and errors, this problem was
the present embodiments are, therefore, to be considered
in all respects as illustrative and not restrictive, and all
to effect ignition of the low-velocity gas m’ from the
solved by the discovery that the low-velocity gas m’ from
changes coming within the meaning and equivalency
the secondary burner ports 46 will readily ignite if at
range of the appended claims are intended to be em
least a part of this low-velocity gas is admitted into fairly
braced herein.
close proximity to the spark-ignited high-velocity gas m
What is claimed is:
1. A high-velocity ?ame pilot burner having internal
from the main burner port 56. While no theory is herein 75
spark ignition comprising a tubular burner body provid
lar in said perpendicular plane, said low-velocity ports
ing a longitudinal passage for the ?ow of a combustible
terminating upstream of the larger base of said collar.
air-gas mixture therethrough, said body having inlet
6. A high-velocity ?ame pilot burner as de?ned in
claim 4, in which said nozzle is removably mounted on the
means at its upstream end for introducing said air~gas
mixture under pressure; a burner head at the downstream
end of said passage, said head having a high-velocity port
located centrally of said passage and a plurality of low
velocity ports in circularly spaced arrangement about
said high-velocity port; a sparking electrode in said pas
sage electrically insulated from said body, the tip of said
electrode ext nding centrally into said high-velocity port
and terminating substantially in the plane perpendicular
downstream end of said longitudinal passage in said
burner body and said burner head is mounted in said
nozzle whereby said nozzle and burner head are remov
able as a unit from said body.
7. A high-velocity ?ame pilot burner of the spark
ignition type, comprising a tubular burner body provid
ing a longitudinal passage for the ?ow of combustible air
gas mixture therethrough, said body having inlet means
at its upstream end for introducing said air-gas mixture
to the axis of said last named port at the downstream
end thereof to de?ne a spark gap with said high-velocity
under pressure; a burner head at the downstream end
port and a grounding electrode secured to said burner 15 of said passage, said head having a high-velocity port
head transversely and downstream of said high~velocity
located centrally of said passage ‘and low-velocity port
means surrounding said high-velocity port and terminating
2. A high-velocity flame pilot burner as de?ned in
claim 1, wherein said burner head is formed to provide
in a point closely upstream thereof; a sparking electrode
supported in said passage and electrically insulated from
an external frusto-conical collar, the conical surface 20 said body, said electrode extending into said high-velocity
port substantially concentrically thereof and terminating
thereof being tapered toward the downstream end of said
high-velocity port to dispose the smaller base of said
substantially at the downstream end of said high-velocity
collar in said perpendicular plane, said low-velocity ports
port whereby said electrode forms a spark gap with said
terminating upstream of the large base of said collar.
high-velocity port; and an insulating spacer on said
3. A high-velocity ?ame pilot burner as de?ned in 25 sparking electrode received in said passage and having
claim 2, wherein said grounding electrode is of thin arcu
apertures for the flow of said air-gas mixture through
ate shape and is secured at its opposite ends to said collar
said passage, said spacer supporting the downstream end
to extend diametrically across said high-velocity port in
of said sparking electrode in said high-velocity port to
closely spaced relation to the end of said electrode.
prevent contact between them, but having a su?iciently
4. A high-velocity ?ame pilot burner as de?ned in 30 loose ?t in said passage to permit it to be centered in said
‘high-velocity port by the ?ow of gas therethrough.
claim 1, which further includes a grounding nozzle adapt
ing said burner for ?ame reciti?cation control, said nozzle
being electrically connected with said burner head and
extending axially beyond the downstream end thereof and
closely surrounding said low-velocity ports whereby ?ames 35
'”g from said ports will sweep along and in contact
with a substantial surface area of said nozzle.
5. A high-velocity ?ame pilot burner as de?ned in
claim 4, wherein said burner head is formed to provide
an external frusto—conical collar, the conical surface 40
thereof being tapered toward the downstream end of said
igh-velocity port to dispose the smaller base of said col
References Cited in the ?le of this patent
Parker _______________ .. July 7, 1931
Borland ____________ __ June 28, 1938
Longini ____________ __ June 25, 1946
Peterson ____________ __ Sept. 27, 1949
Tavener ____________ __ Mar. 11, 1952
Rowell ______________ __ July 2, 1957
Keyes ______________ __ Nov. 4, 1958
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