U.S. patent number RE28,679 [Application Number 05/307,199] was granted by the patent office on 1976-01-13 for burners.
This patent grant is currently assigned to International Industries Ltd.. Invention is credited to Edgar Clarence Robinson.
United States Patent |
RE28,679 |
Robinson |
January 13, 1976 |
Burners
Abstract
An oil burner consists of an outer jacket surrounded and spaced
from an inner burner tube to provide a surrounding counterflow
chamber. Jacket and tube project horizontally inwards from the
surrounding combustion chamber wall. Counterflow chamber is
substantially closed at both ends. Tube projects inwardly beyond
counterflow chamber and terminates in an upfacing burner head.
Communication exists at opposite ends of the part of tube
surrounded by counterflow chamber. At startup a tongue of flame
travels through tube from an injector nozzle. Part of flame
counterflows back through surrounding chamber and recirculates
through tube. Another part of flame proceeds on to burner head.
When parts sufficiently heated, flame in tube is caused to be
extinguished and is replaced by hot clear blue flame jets from
burner and a multiapertured band in tube within limits of
counterflow chamber at end thereof remote from nozzle where
counterflow originates. Combustion-supporting air to both chambers
adjustably admitted at nozzle end.
Inventors: |
Robinson; Edgar Clarence (North
Vancouver, CA) |
Assignee: |
International Industries Ltd.
(Burnaby, CA)
|
Family
ID: |
26713694 |
Appl.
No.: |
05/307,199 |
Filed: |
November 16, 1972 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
036987 |
May 13, 1970 |
03620657 |
Nov 16, 1971 |
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Current U.S.
Class: |
431/9;
431/116 |
Current CPC
Class: |
F23D
11/00 (20130101) |
Current International
Class: |
F23D
11/00 (20060101); F23L 007/00 () |
Field of
Search: |
;431/9,115,116,188 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Favors; Edward G.
Attorney, Agent or Firm: Kent; C. C. Hill; K. M.
Claims
What is claimed is:
1. In the art of combusting flammable fluid fuel for creating
heated gas, the method steps which are characterized by:
i. initially projecting a relatively long tongue of ignited fuel
longitudinally from a source to a principal burning zone remote
from said source,
ii. causing an opposite, counterflow of a part of said tongue back
towards said source, the originating location of said counterflow
being between said source and said principal burning zone,
iii. reintroducing said counterflow back into said tongue near said
source,
iv. causing the flame of said tongue to be extinguished when a
sufficient rise in ambient temperature has supervened, and
substantially simultaneously therewith
v. causing the generation of a blue flame at the said originating
location of counterflow, and at said principal burning zone,
and
vi. introducing sufficient air to .[.meet the requirements
aforesaid, said burning zone being further from said source than
said original location of counterflow..]. .Iadd.said burner to
support combustion..Iaddend.
2. The method according to claim 1 which includes the step of
admitting additional counterflow air to mix with said first
mentioned counterflow. .[.3. The method according to claim 1 which
is effected within a surrounding combustion chamber and which
includes the steps of:
i. admitting additional counterflow air to mix with said first
mentioned counterflow, and
ii. admitting air to said combustion chamber from a location near
said source to mix with said tongue of ignited fuel within said
combustion chamber..]. .[.4. A fluid fuel burner embodying an inner
burner tube, a surrounding jacket, said tube and said jacket each
having a first end and adjacent second ends, said jacket being
spaced from said tube, a fuel nozzle assembly, an ignition
electrode and sufficient air intake means, the foregoing being
characterized by including:
i. a burner head, on the first end of said tube,
ii. means for providing a counterflow of ignited fuel through a
counterflow chamber existing between and by virtue of said tube and
said jacket, said counterflow being opposite in direction to the
flow of, and consisting of a portion of, a tongue of flammable
fluid projecting through said tube from said nozzle assembly
iii. the originating location of said counterflow being between
said nozzle assembly and said burner head
iv. means for reintroducing said counterflow back into said inner
tube near said nozzle assembly, and
v. means for causing the flame of said tongue to be extinguished
when a sufficient rise in ambient temperature has supervened, and
substantially simultaneously therewith thereby causing the
generation of a blue flame at the said originating location of
counterflow, and at a principal burning zone, said burning zone
being further from said nozzle assembly than said
originating location of counterflow..]. 5. A fluid fuel burner
.[.embodying.]. .Iadd.including in combination with .Iaddend.an
inner burner tube, a surrounding jacket, said tube and jacket each
having a first end and adjacent second ends said jacket being
spaced from said tube, a fuel nozzle assembly, an ignition
electrode and .[.sufficient.]. .Iadd.combustion supporting
.Iaddend.air intake means .[., the foregoing being characterized by
including.]. :
i. a burner head .[.on.]. .Iadd.at .Iaddend.the first end of said
tube
ii. first and second end walls for said jacket providing a
counterflow chamber therebetween surrounding said inner tube, said
inner tube admitting fuel at said second end and discharging it at
said first end,
iii. said second wall extending between said jacket and inner tube
adjacent said nozzle assembly
.[.iv. said inner tube being vented to an external side of said
chamber at the first end of said jacket,.].
v. said first end wall being predominantly imperforate but
.[.sufficiently apertured as to permit.]. .Iadd.having aperture
means for permitting .Iaddend.a limited volume of counterflow air
into said surrounding .Iadd.counterflow .Iaddend.chamber,
vi. said inner tube being of greater length than said jacket and
projecting through an aperture provided therefor in said first end
wall,
vii. said inner tube providing communication with said chamber
adjacent both said end walls for the counterflow .Iadd.from
.Iaddend.and reintroduction .[.respectively.]., to said inner tube
of products of combustion burnt within said inner tube,
viii. said burner head being upon the first end portion of said
inner tube which end projects through said first end wall to said
external side of
said .Iadd.counterflow .Iaddend.chamber. 6. The invention according
to claim 5 in which said communication between said inner tube and
said .Iadd.counterflow .Iaddend.chamber adjacent the first end wall
thereof is in the form of an annular band comprised of a
multiplicity of apertures in
said inner tube. 7. The invention according to claim 6 in which
said communication between said inner tube and said
.Iadd.counterflow .Iaddend.chamber adjacent the second end wall
thereof includes an annular space between the second end of said
tube and said second end wall. .[.8. The invention according to
claim 6 in which said communication between said inner tube and
said chamber adjacent the second end wall thereof is in the form of
an annular band comprised of a multiplicity of apertures in said
inner tube..]. .[.9. The invention according to claim 8 in which
said communication between said inner tube and said chamber
adjacent the second end wall thereof also includes an annular space
between the adjacent end
of said tube and said second end wall..]. 10. The invention
according to claim .[.9.]. .Iadd.7 .Iaddend.which is also
characterized by the provision of an air intake aperture in said
second wall, a frustoconical funnel secured to the rim of said
aperture substantially on the vertex plane thereof, said fuel
nozzle assembly .[.and said ignition electrode.].
projecting into said funnel. 11. The invention according to claim
10 in which said burner is secured to and projects inwardly from
the wall of a combustion chamber, and .[.adjustable.]. .Iadd.air
distributing .Iaddend.means on the external side of said wall for
.[.varying the admission.]. .Iadd.balancing the volume .Iaddend.of
combustion supporting air .[.to.]. .Iadd.between .Iaddend.the
interior of said combustion chamber and .[.into.]. .Iadd.the
vicinity of .Iaddend.said .[.funnel through venting.].
.Iadd.combustion tube through aperturing in said funnel and
.Iaddend.in said wall upon the outer side of said jacket .[...].
.Iadd., all said aperturing being within the confines of said
distributing
means. .Iaddend. 12. The invention according to claim 5 which is
also characterized by including a multiapertured air-distributing
plate on the counterflow chamber side of said first end wall,
slightly spaced
therefrom. 13. The invention according to claim .[.9.]. .Iadd.7
.Iaddend.which is also characterized by including a multiapertured
air-distributing plate on the counterflow chamber side of said
first end
wall, and slightly spaced therefrom. 14. The invention according to
claim 5 in which said burner head is characterized by being secured
to the fuel discharge end of said inner tube, said head being in
the form of an outflared and rimmed head formation, and at least
one multiapertured fuel
jet plate spanning said rim. 15. The invention according to claim
.[.10.]. .Iadd.7 which is also characterized by the provision of an
air intake operature in said second wall, a frusto-conical funnel
secured to the rim of said operature substantially on the vertex
plain thereof, said fuel nozzle assembly and said ignition
electrode projecting into said funnel and .Iaddend.in which said
burner head is characterized by being secured to the first end of
said inner tube, said head being in the form of an outflared and
rimmed head formation and at least one multiapertured fuel
jet plate spanning said rim. 16. The invention according to claim 5
in which said burner head is characterized by being secured to the
first end of said inner tube, said head being in the form of an
outflared and rimmed head portion, and a pair of closely spaced and
parallel, multiapertured fuel jet plates spanning said rim, said
burner in situ being axially horizontal with said inner tube
horizontal and said burner head generally right-angularly disposed
with said inner tube axis so that said head formation opens
upwardly with the rim thereof lying in a horizontal plane.
7. The invention according to claim .[.10.]. .Iadd.15 .Iaddend.in
which said burner head is characterized by being secured to the
first end of said inner tube, said head being in the form of an
outflared and rimmed head portion, and a pair of closely spaced and
parallel multiapertured
fuel jet plates. 18. The invention according to claim 6 which is
also characterized by including a multiapertured air-distributing
plate on the counterflow chamber side of said first end wall, and
slightly spaced
therefrom. 19. The invention according to claim 6 in which said
communication between said inner tube and said chamber adjacent the
second end wall thereof includes an annular space between the
adjacent end of
said tube and said second end wall. 20. The invention according to
claim 19 in which said burner is secured to and projects inwardly
from the wall of, a combustion chamber, and .[.adjustable.].
.Iadd.air distributing .Iaddend.means on the external side of said
wall for .[.varying the admission.]. .Iadd.admitting variable
volumes .Iaddend.of combustion supporting air .Iadd.and
distributing said air separately to the vicinity of the second end
of said inner burner tube and .Iaddend.to the interior of said
combustion chamber .[.and into said counterflow chamber..].
.Iadd...Iaddend. 21. The invention according to claim .[.3.].
.Iadd.1 which is effected within a surrounding combustion chamber
and which includes the steps of:
admitting additional counterflow air to mix with said first
mentioned counterflow, and
admitting air to said combustion chamber from a location near said
source to mix with said tongue of ignited fuel within said
combustion chamber, and .Iaddend.which includes the step of
preventing the reignition of said tongue by said counterflow after
it has been vaporized by said temperature
rise and extinguished. 22. .[.The invention according to claim 4
which includes.]. .Iadd.A fluid fuel burner embodying an inner
burner tube, a surrounding jacket, said tube and said jacket each
having a first end and adjacent second ends, said jacket being
spaced from said tube, a fuel nozzle assembly, an ignition
electrode and combustion supporting air intake means, and including
in combination:
i. a burner head, on the first end of said tube
ii. means for providing a counterflow of ignited fuel through a
counterflow chamber existing between said tube and said jacket,
said counterflow being opposite in direction to the flow of, and
consisting of a portion of, a tongue of flammable fluid projecting
through said tube from said nozzle assembly,
iii. the originating location of said counterflow being between
said nozzle assembly and said burner head,
iv. means for reintroducing said counterflow back into said inner
tube near said nozzle assembly, and
v. means for causing the flame of said tongue to be extinguished
when a sufficient rise in ambient temperature has supervened, and
substantially simultaneously therewith thereby causing the
generation of a blue flame at the said originating location of
counterflow, and at said burner head, and
vi. .Iaddend.means for preventing the reignition of said tongue by
said counterflow after it has been vaporized by said temperature
rise and
extinguished. 23. The invention according to claim 5 which includes
flame arrestor means in said counterflow chamber for preventing the
reignition of said tongue by said reintroduced products of
combustion after said
tongue has been vaporized by said temperature rise and
extinguished. 24. The invention according to claim 12 which
includes an annular apertured flame arrestor plate spanning said
counterflow chamber between said tube and said jacket, said plate
being relatively near the second ends of said tube and jacket, said
plate preventing the reignition of said tongue by said counterflow
after .[.it.]. .Iadd.said tongue .Iaddend.has been vaporized by
said temperature rise and extinguished. .Iadd. 25. For use in
combination with a burner tube adapted and designed to project into
a combustion chamber from the enclosure defining said chamber, air
distributing means on the exterior side of said enclosure, said
distributing means being apertured for air admission and
communication with:
a. the interior of said burner tube,
b. said combustion chamber, means for automatically, separately,
and simultaneously feeding air into said tube and into said
combustion chamber according to the relative barometric demands of
said tube and combustion chamber, and means for isolating the
proportion of air fed into said combustion chamber against entry
into said burner tube at least in the vicinity of said location
from which said burner tube projects into said combustion
chamber;
said air distributing means being secured to and projecting
outwardly from said enclosure, said enclosure being apertured
within the confines of said housing so as to be enclosed thereby
and permit the passage of air within said distribution housing
therethrough into said combustion chamber. .Iaddend..Iadd. 26. The
invention according to claim 25 which includes a venturi funnel for
a fuel nozzle positioned in said distributing housing, said funnel
being secured and substantially sealed around its reduced discharge
end against air admission other than through the enlarged intake
end thereof, said funnel being substantially co-axial with said
tube. .Iaddend. .Iadd. 27. The invention according to claim 26 in
which said funnel is situated substantially central of said
distributing housing the aperturing in said enclosure being
arranged about said funnel and spaced therefrom. .Iaddend..Iadd.
28. The invention according to claim 27 in which said air intake
housing includes a surrounding apertured wall secured against and
projecting outwardly from said enclosure and an end plate spanning
said apertured wall, a plenum chamber occupying the space between
said apertured wall, said end plate, and the portion of said
combustion chamber enclosure bounded by said apertured wall.
.Iaddend..Iadd. 29. The invention according to claim 22 in which
said burner projects into a combustion chamber from a location at
least near to a portion of the enclosure defining said chamber, air
distributing means on the exterior side of said enclosure, said
distributing means being apertured for air admission thereto and
air communication with:
a. the interior of said burner tube,
b. said combustion chamber,
means for automatically, separately, and simultaneously feeding air
into said tube and into said combustion chamber from said air
distributing means according to the barometric demands of said
combustion chamber, and means for isolating the proportion of air
fed into said combustion chamber against entry into said burner
tube at least in the vicinity of said location from which said
burner tube projects into said combustion chamber. .Iaddend..Iadd.
30. The invention according to claim 5 in which said burner
projects into a combustion chamber from a location at least near to
a portion of the enclosure defining said chamber, air distributing
means on the exterior side of said enclosure, said distributing
means being apertured for air admission and communication with:
a. the interior of said burner tube,
b. said combustion chamber,
means for automatically, separately, and simultaneously feeding air
into said tube and into said combustion chamber from said air
distributing means according to the barometric demands of said
combustion chamber, and means for isolating the proportion of air
fed into said combustion chamber against entry into said burner
tube at least in the vicinity of said location from which said
burner tube projects into said combustion chamber. .Iaddend..Iadd.
31. The invention according to claim 7 in which said burner
projects into a combustion chamber from a location at least near to
a portion of the enclosure defining said chamber, air distributing
means on the exterior side of said enclosure, said distributing
means being apertured for air admission and communication with:
a. the interior of said burner tube,
b. said combustion chamber,
means for automatically, separately, and simultaneously feeding air
into said tube and into said combustion chamber according to the
barometric demands of said combustion chamber, and means for
isolating the proportion of air fed into said combustion chamber
against entry into said burner tube at least in the vicinity of
said location from which said burner tube projects into said
combustion chamber. .Iaddend..Iadd. 32. The invention according to
claim 22 in which said burner projects into a combustion chamber
from a location at least near to a portion of the enclosure
defining said chamber, air distributing means on the exterior side
of said enclosure, said air distributing means being apertured for
air admission and communication with:
a. the interior of said burner, and
b. said combustion chamber,
means for automatically, separately, and simultaneously feeding air
into said tube and into said combustion chamber according to the
barometric demands of said combustion chamber, and means for
isolating the proportion of air fed into said combustion chamber
against entry into said burner tube at least in the vicinity of
said location from which said burner tube projects into said
combustion chamber, said air distributing means being in the form
of an apertured air intake housing secured to and projecting
outwardly from said enclosure, said enclosure being apertured
within the confines of said housing to permit the passage of air
within said distribution housing therethrough into said combustion
chamber, said burner tube lying within the produced boundary of
said housing, a venturi channel for a fuel nozzle positioned in
said distributing housing, the reduced end of said funnel lying
substantially on the plane of said enclosure, said funnel being
secured on said plane and substantially sealed around its reduced
discharge end against air passage other than through the enlarged
intake end thereof, said funnel being substantially co-axial with
said tube, said funnel being situated substantially central of said
distributing housing, the aperturing in said enclosure being
arranged about said funnel and spaced therefrom, said air intake
housing including a surrounding apertured wall projecting outwardly
from said enclosure and an end plate spanning said apertured wall,
a plenum chamber occupying the space between said apertured wall,
said end plate, and the portion of said combustion chamber
enclosure bounded by said apertured wall. .Iaddend..Iadd. 33. The
invention according to claim 5 in which said burner projects into a
combustion chamber from a location at least near to a portion of
the enclosure defining said chamber, air distributing means on the
exterior side of said enclosure, said air distributing means being
apertured for air admission and communication with:
a. the interior of said burner, and
b. said combustion chamber,
means for automatically, separately, and simultaneously feeding air
into said tube and into said combustion chamber according to the
barometric demands of said combustion chamber, and means for
isolating the proportion of air fed into said combustion chamber
against entry into said burner tube at least in the vicinity of
said location from which said burner tube projects into said
combustion chamber, said air distributing means being in the form
of an apertured air intake housing secured to and projecting
outwardly from said enclosure, said enclosure being apertured
within the confines of said housing to permit the passage of air
within said distribution housing therethrough into said combustion
chamber, said burner tube lying within the produced boundary of
said housing, a venturi funnel for a fuel nozzle positioned in said
distributing housing, the reduced end of said funnel lying
substantially on the plane of said enclosure, said funnel being
secured on said plane and substantially sealed around its reduced
discharge end against air passage other than through the enlarged
intake end thereof, said funnel being substantially co-axial with
said tube, said funnel being situated substantially central of said
distributing housing, the aperturing in said enclosure being
arranged about said funnel and spaced therefrom, said air intake
housing including a surrounding apertured wall projecting outwardly
from said enclosure and an end plate spanning said apertured wall,
a plenum chamber occupying the space between said apertured wall,
said end plate, and the portion of said combustion chamber
enclosure bounded by said apertured wall. .Iaddend..Iadd. 34. A
fluid fuel burner including an inner burner tube having at a first
end thereof a burner head, and a jacket surrounding part of said
tube, characterized in that said jacket has a first end wall and a
centrally apertured second end wall, said jacket and end walls
defining a counterflow chamber around said inner tube, said inner
tube being annularly perforated in the vicinity of said first end
wall and within the confines of said first and second end walls,
said inner tube and counterflow chamber being in communication in
the vicinity of said second end wall and within the confines of
said first and second end walls, an air distributing housing
overlying said second end wall on the exterior side thereof, means
for admitting air into said housing, a venturi funnel within said
housing communicating with the interior of said housing and with
said second end wall central aperture, said funnel being
substantially coaxial with said inner tube, an injection nozzle for
pulverized fuel, and aperture means within the confines of said
housing and communicating between the interior of said housing and
the space surrounding said burner. .Iaddend. .Iadd. 35. The
invention according to claim 5 in which said first end wall is
sufficiently apertured to admit said limited volume of
counterflowing air. .Iaddend. .Iadd. 36. The method according to
claim 1 which is effected within a surrounding combustion chamber
and which includes the steps of admitting air to an air
distributing means and dividing said air within said distributing
means into two essentially enclosed and separate air streams one of
which mixes with said ignited fuel and the other of which enters
said combustion chamber. .Iaddend..Iadd. 37. A fluid fuel burner
embodying an inner burner tube, a surrounding jacket, said tube and
said jacket each having a first end and adjacent second ends, said
jacket being spaced from said tube, a fuel nozzle assembly, an
ignition electrode and combustion supporting air intake means, and
including in combination:
i. a burner head, at the first end of said tube,
ii. means for providing a counterflow of ignited fuel through a
counterflow chamber existing between said tube and said jacket,
said counterflow being opposite in direction to the flow of, and
consisting of a portion of a tongue of flammable fluid projecting
through said tube from said nozzle assembly,
iii. the originating location of said counterflow being between
said nozzle assembly and said burner head,
iv. means for reintroducing said counterflow back into said inner
tube near said nozzle assembly, and
v. means for causing the flame of said tongue to be extinguished
when a sufficient rise in ambient temperature has supervened, and
substantially simultaneously therewith thereby causing the
generation of a blue flame at the said originating location of
counterflow, and at said burner head. .Iaddend..Iadd. 38. The
invention according to claim 15 in which said burner is secured to
and projects inwardly from the wall of a combustion chamber having
air venting in said wall upon the outer side of said jacket and air
distributing means on the external side of said wall enclosing said
venting, for admitting combustion supporting air to (a) the
interior of said combustion chamber through said venting, and (b)
through said funnel to said burner tube..Iaddend.
Description
BACKGROUND OF THE INVENTION
The present invention relates to oil burners suitable for use in
heating installations of various kinds but particularly for those
intended for use in association with domestic heating units and
especially domestic hot water heating units.
Oil-burning hot-water heaters of the type used in many households
are unable to operate efficiently due in part to the design of the
burners thereof and partly because the oil and air which provides
the combustible mixture are both fed to such burners under
considerable pressure. The combustion chambers of most domestic
burners are considerably smaller than those of commercial hot water
heaters for example. As a result of these considerations fuel tends
to be swept through these chambers before it can be preheated and
mixed thoroughly as is necessary if a high rate of heat release is
to be achieved. A high-pressure burner requires that the combustion
chamber associated therewith be lined with a refractory material,
and to sustain combustion this material must be incandescent.
However since the demand for hot water is not great or frequent,
such burners only operate at fairly widely spaced intervals and
then usually for only a short period of time. Accordingly, at each
time of use the burner should be brought up to an operating
temperature which will permit the fuel to burn properly. But length
warmup further reduces the effectiveness of such burners because in
fact the surrounding refractory material is not brought up properly
to incandescence each time and as a result, conventional hot water
heating equipment and especially conventional domestic hot-water
heating equipment operates considerably below optimum efficiency
from the standpoint of economy as well as from the standpoint of
frequency of maintenance which is required to keep an inefficient
burner clean.
BRIEF SUMMARY OF THE INVENTION
The invention consists of means for accomplishing the method steps
which are characterized by initially projecting a relatively long
jet or tongue of flame from ignited fuel longitudinally from an
injecting nozzle assembly to a principal burning zone which is
remote therefrom and well within (usually substantially centrally
within) a surrounding axially vertical combustion chamber.
Simultaneously with what has just been stated, a counterflow of a
part of said jet or tongue is caused to travel oppositely or back
toward the general region from whence the flame emerges from the
nozzle assembly, the counterflowing part returning somewhat as
might a fountain having a ring of jets around a central jet, or as
petals might droop from a flower except that the flow here being
referred to is horizontal. The originating location of the
counterflow is between the nozzle assembly or source of flame and
the aforesaid principal burning zone. The counterflow is
reintroduced back into the main central jet or tongue near the said
source or nozzle assembly.
The next step in the accomplishment of the present invention is
that of separating the tongue of flame from the nozzle when a
sufficient rise in ambient temperature has supervened. This
separation and extinguishment of the flame tongue is caused by the
turning off of the ignition electrode adjacent the aforesaid
nozzle. In the action of extinguishment the flame leaves the
vicinity of the nozzle assembly travelling the full length of the
burner to appear in the form of a multiplicity of clean blue
uniform flame jets at the mentioned principal burning zone. At the
same time a band of similar clear blue flame jets appears at the
originating location of counterflow. The principal burning zone is
further from the nozzle assembly than the originating location of
counterflow. While the aforesaid main tongue of flame travels
horizontally, the firstmentioned multiplicity of blue flame jets
are projected vertically upwards within the combustion chamber. In
the conclusion, in this context, it will accordingly be recognized
that there is visible within the combustion chamber from the
outside thereof after the burner has been brought up to optimum oil
vaporizing heat, only the horizontal upwardly facing disc of blue
flame jets.
The novel objects achieved by the burner structure which produces
the above forms of visible heat may be stated as follows:
The burner is designed for consuming any fuel from kerosene to Type
2 furnace oil without adjustment. At this point another particular
novel feature of the burner may be stated as residing in the fact
that it operates at atmospheric pressure and requires no forced
draft, the only point at which a small quantity of air under
pressure is admitted to the burner being at the injection nozzle
assembly thereof where such pressure is in the order of up to 10
p.s.i. as a rule, this being substantially solely for the purpose
of breaking up and impelling particles of oil mixed with air into
the burner at the point where the fuel is ignited.
A novel advantage flowing from the last aforementioned objective
lies in the fact that such a burner both starts up and operates at
sound levels which are low and comparable to existing gas fired
units which are well known to have acoustic advantages. At the same
time, due to its high recovery rate the present burner would appear
to be favorably competitive with gas in terms of consumption
costs.
A further novel objective achieved by the present burner and also
flowing from what has already been stated resides in that operation
at atmospheric pressure, or in other words, with natural draft,
eliminates one of the biggest service problems which is that of the
`linting up` of oil burners. By this is meant the accumulation of
dust and lint upon the fan blades of a forced draft blower, also
the accumulation of such materials upon the parts surrounding and
adjacent the fan whereby the area of air entry into the burner is
diminished, and also the charring of the burner orifices with lint
mixed with incompletely burned oil due to the slowing down of the
fan blades consequent upon the deposit of said lint thereon whereby
the air intake capacity is decreased and hence the combustibility
of fuel within the burner.
A yet further novel feature of the present burner arising out of
its quietness of running is its suitability for oil-burning use
(particularly when the burner plates are made rectangular instead
of circular as herein) in association with clamshell heat
exchangers as used in automobile trailers, cabin cruisers and the
like, which are extremely easy to manufacture and assemble, and are
relatively deep, wide, cross-sectionally narrow, and more or less
corrugated being fomed of two similar stampings edge joined and
between which the burner is placed usually in multiples of three.
.Iadd.
A further important novel object is the provision of means for
feeding separate air to the initial mixing zone between the burner
tube and fuel nozzle, and to the combustion chamber so that the two
main bodies of combustion supporting air may be "balanced"
according to atmospheric conditions. These means essentially embody
an air distributing housing secured against the combustion chamber
wall so as to cover and enclose both the air passages to said
mixing zone and said combustion chamber within a common plenum, the
said air passages thus being served from one air body inside the
distributor housing, all to the end of maintaining as nearly as
possible a substantially constant volumetric intake of air into the
burner tube regardless of the air pressure (i.e., barometric
conditions) in the combustion chamber surrounding the burner so
that, in turn, a hot blue flame will be maintained at the burner
head substantially regardless of barometric combustion chamber
variations. .Iaddend.
A further objective achieved by the burner consists of efficiencies
in the order of 84 percent combined with the employment of a
burning process which is nearly perfect, the combustion gases
containing only traces of CO and no visible smoke or soot. As a
result, the low stack temperature achieved can be advanced to the
authorities concerned in favor of permitting the main chimney for
such a burner to employ type "B" vents as presently allowed for
gas-fired units only.
A further object is to vaporize a tongue of fuel within an inner
burner type by a surrounding counterflow to provide means for
preventing it from becoming reignited.
Further objectives attained by the present burner reside in the
design and arrangement of the same which renders it easily
adaptable to replacement of existing oil-fired burners, quick and
easy withdrawal of the unit for maintenance purposes and consequent
reduction in maintenance costs, fewness of moving parts thus
further simplifying servicing due to wear-out, the provision of a
nozzle the exit orifice of which is very considerably larger than
with conventional burners resulting in a relatively cool nozzle
temperature and the elimination of plugging by dirt and hence
carbon buildup while at the same time providing a nozzle assembly
which is located externally of the fuel combustion chamber and
hence away from the high-temperature zone with its quickly
deteriorating effect upon a nozzle, and the production of a flame
which does not need a refractory or stainless steel combustion
chamber hence resulting in reduced weight, price and
maintenance.
Further novel objectives reside in that the purchaser is not
obliged to outlay the expense of a fan or blower and in that a
useful space saving is achieved particularly in small housing units
due to the elimination of a fan or blower and associated motor for
operating the same.
With the foregoing in view, and such other or further purposes,
advantages or novel features as may become apparent from
consideration of this disclosure and specification, the present
invention consists of the inventive concept which is comprised,
embodied, embraced, or included in the method, process,
construction, composition, arrangement or combination of parts, or
new use of any of the foregoing, herein exemplified in one or more
specific embodiments of such concept, reference being had to the
accompanying Figures in which:
FIG. 1 is a plan representation of the invented oil burner.
FIG. 2 is a sectional elevation substantially on the line 2--2 of
FIG. 1.
FIG. 3 is an end elevation as viewed from the right of FIG. 2.
FIG. 4 is a plan representation for the purpose of orientating and
depicting in situ the invented oil burner in and with respect to an
enclosing combustion chamber.
FIG. 5 is a representation of the flame travel immediately
following startup.
FIG. 6 is a representation similar to FIG. 5 some 60 to 90 seconds
after startup.
FIG. 7 is a circuit detail showing an example of a means for
causing the flame tongue to be extinguished when a sufficient rise
in ambient temperature is supervened.
In the drawings like characters of reference designate similar
parts in the several Figures.
PRELIMINARY DESCRIPTION
Stated in terms generally consonant with those of the accompany
claim or claims to aid in construing the same the invention
includes an inner burner tube A, a surrounding jacket B, said tube
and jacket each having first ends C and D respectively, and
adjacent second ends E and F respectively, said jacket being spaced
from said tube, a fuel nozzle assembly G, and an ignition electrode
H characterized by including (i) a burner head J on the first end
of said tube, (ii) means in the form of a first end wall K (the
second end wall being L), the multi-apertured first and second
annular bands M and N, and the tube and jacket A and B respectively
defining the surrounding counterflow chamber O, for providing a
counterflow of ignited fuel P (FIG. 5) through said counterflow
chamber O, said counterflow P being opposite in direction to the
flow, and consisting of a portion of, a tongue Q of flammable fluid
projected through tube A from nozzle assembly G, (iii) the original
location R of the aforesaid counterflow being between the said
nozzle assembly and the said burner head, (iv) means comprising in
combination the aforesaid second band N and the annular space S for
reintroducing counterflow P back into inner tube A, and (v) means
consisting of a thermostatic cutout for causing flame tongue Q to
be extinguished when a sufficient rise in ambient temperature has
supervened, and simultaneously therewith thereby causing the
generation of a blue flame T at originating location R and at a
principal burning zone U, said burning zone being further from
nozzle assembly G than originating location of counterflow R.
.Iadd.Burner tube A encloses a fuel chamber V. Arranged closely
around jacket B are air intake apertures X. Covering and enclosing
the pathways of ambient air into both the air and fuel mixing
funnel of assembly G and the said apertures X is a variable air
distributing housing Y. .Iaddend.
DETAILED DESCRIPTION
The burner collectively designated 10 is secured to the wall 12 of
the surrounding conventional combustion chamber 14 so as to project
horizontally into the combustion chamber.
The burner per se comprises, in combination with the aforesaid
inner burner tube A, surrounding jacket B, wherein the jacket is
spaced from the tube, a fuel nozzle assembly G and an ignition
electrode H when characterized by including the following
features:
A first end generally designated 16 and a second end generally
designated 18, the first end having an imperforate end wall 20 and
the second having an imperforate second end wall 22. These end
walls, together with the jacket B, and the portion 24 of tube A
which is between said end walls define the aforesaid counterflow
chamber O which is best seen from FIG. 2 to be relatively elongated
and of annular configuration.
Although it has been said that the end walls 20 and 22 are
imperforate, they are nevertheless provided with the central
apertures 26 and 28 respectively, through the former of which tube
A extends, and with sufficient clearance, centrally of said
aperture as to provide .Iadd.what is collectively designated as
.Iaddend.an annular combustion supporting structure 30. Second end
wall 22 is centrally apertured at 28 to provide an intake orifice
for the elongated flame tongue Q, a frustoconical funnel 32 being
secured to the perimeter of aperture 28 upon the external side of
chamber 14 to accommodate ignition assembly G and electrode H.
Burner head J is in the form of an outflared and rimmed formation
or somewhat circular washbasin shaped. Spanning the rim thereof is
a pair of slightly spaced multiapertured fuel jet plates 34. Burner
tube A is held centered within jacket B by two discoid rings, one
of which is styled an apertured air distributor 36 slightly spaced
from plate 20 within chamber O. The other is a flame arrestor plate
38, secured to tube A and jacket B as clearly depicted to prevent
reignition of the flame of tongue Q after it has been extinguished
and vaporized as will hereinafter be explained.
Communication between inner tube A and counterflow chamber O is
provided by means of a first annular band 40, a second annular band
42, and an annular space 44. Both annular bands are multiapertured,
said apertures being designated 46. Annular space 44 is located
between the second end D and second end wall L. A pair of aligned
central and relatively enlarged apertures 48 are provided in jet
plates 34. Flanges 50 overlap the opposite ends of jacket B (which
is for all practical purposes coincident with combustion chamber
wall 12). Secured upon the external side of said wall (in other
words to the right of said wall as appears from FIG. 2) are
adjustable .Iadd.air distributing .Iaddend.means collectively
designated 52 .Iadd.(including the housing Y) .Iaddend.for
.[.varying the admission of.]. .Iadd.a .Iaddend.combustion
supporting air .Iadd.stream which flows simultaneously and
according to demand through the funnel 32 and apertures X
.Iaddend.to the interior of tube A and the surrounding combustion
chamber 14 .Iadd.respectively.Iaddend.. These means consist of an
annular outwardly projecting wall 54 and end plate 56. Wall 54 is
provided with a set of spaced .Iadd.air .Iaddend.apertures 58.
Overlying wall 54 is a ring 60 provided with apertures of the same
size as apertures 58 and capable of registration or partial
registration therewith upon rotation of the ring which is normally
held clamped to wall 54 by means of the conventional nut and bolt
bracket assembly collectively designated 62 (FIG. 3).
OPERATION
Upon operation of the associated pump (not shown) air therefrom at
4 to 7 p.s.i. enters nozzle assembly G where it creates a partial
vacuum thereby attracting oil from the associated oil pump, (also
not shown) to be mixed with said air and expelled through the
orifice 28. Approximately on the plane of such orifice electrode H
ignites the oil and air mixture to create a long luminous tongue
flame commencing substantially at the nozzle orifice and extending
clear through burner tube A and through burner head J. At the same
time an outer annular layer of the tongue of flame is so to say
stripped off and proceeds through first annular band 40 into the
original location of the commencement of counterflow R it
counterflows through chamber O oppositely back through flame
arrestor plate 38, annularly or radially inwards through second
apertured annular band 42 as well as through annular space S to
recirculate again toward burner head J within burner tube A.
The just-stated process continues for some 60 to 90 seconds. At
that time ignition electrode H is automatically inactivated. This
causes the flame of the tongue Q to be extinguished since it is to
be understood that under normal operating conditions after some 60
to 90 seconds a sufficient rise in ambient temperature has
supervened to vaporize the air and oil mixture expelled from
orifice G. At the same time as electrode H is inactivated, a
multiplicity of small blue jets of flame 64 are established on the
outer surface of first annular band 40 as a result of the intake of
.[.fresh.]. air as indicated by arrow 66 .[.around the annular
combustion supporting.]. .Iadd.through .Iaddend.aperture .[.30.].
.Iadd.26.Iaddend.. Such intake of air is also distributed in the
narrow annular space 68 between the otherwise imperforate end plate
20 and perforated distributor ring 36 .[.. Thus.]. .Iadd., thus
.Iaddend.assisting the completion of combustion not only at the
location R but usefully throughout the entire adjacent region of
counterflow chamber O and to some extent through the entire
chamber.
It is to be understood that by this time the temperature of the
burner has reached a point where the air and oil mixture is
immediately vaporized into a gas upon entry past orifice 28. The
kinetic energy of the nozzle assembly G also draws air as indicated
at 70 through apertures 58 into funnel 32 to mix with the air oil
mixture. In addition, combustion supporting air also enters through
said apertures 58 as indicated at 72 for the purpose of aiding the
completion of combustion within chamber 14. .Iadd.As a result,
combustion-supporting input air in the form of what is herein
designated as primary and secondary air streams 72 and 70
respectively entering the right or second end (with respect to FIG.
2) is "balanced across the burner" so that if for example high
barometric stack pressure is obtaining, more air is admitted to 14
but less to burner tube A so as not to change the character of
flame, such as would happen if air were admitted to the tube A
proportionately with an increase in negative pressure. It will be
noted by best reference to FIG. 2 and the shown openings X and 28
therein that the said primary and secondary air streams 70 and 72
are separate from each other. The intake at aperture 26 may for
convenience be referred to as a tertiary air stream.
If the burner has been preset for example so as to provide a hot
blue flame at or about normal ambient barometric pressure, the
performance of the air distributing means 52 in the achievement of
its object, namely the maintenance of such a flame regardless of
ambient barometric variation can be described as follows:
Let it be assumed that there is .02 inches of water column negative
in combustion chamber 14. Air enters Y through ports 58 and then
divides into the primary stream 72 to enter 14 through aperture X,
and secondary stream 70 to enter the burner tube A by way of funnel
32.
Since the two air streams 70 and 72 are separate, substantially the
only draw upon 70 is that caused by the aspirating effect of the
nozzle assembly G which is invariant. If therefore the barometric
pressure in combustion chamber 14 be increased to 0.08 WC negative
there is an immediate increase in demand upon the air within the
distributing housing Y. This is satisfied by an increase of air
stream 72 through apertures X at the expense of air stream 70 which
is slightly reduced due to the creation of a small pressure drop
between the intake of funnel 32 and the adjacent end plate or wall
56. Thus the combustion air entering housing X due to being split
into two streams which are separate, and led, the one to the
combustion chamber 14 and the other to the burner tube, is
automatically balanced resulting in a substantially constant blue
flame. This condition would not obtain if the combustion chamber
air intake 72 and the burner tube intake 32 each communicated
separately directly with the surrounding air. In that case by
contrast there would be an equal pressure draw into the combustion
chamber and into the burner tube. Such draw in the case of air
stream 70 would be mainly through the burner plate orifices
detrimentally changing the character of the flame T. .Iaddend.
During the first 60 to 90 seconds of operation while the flame Q is
luminous it will be understood that it is luminous flame which also
counterflows in chamber O and which proceeds onwardly to and
through jet plates 34 including the central spire of flame 74. When
vaporizing heat has been achieved, the tongue Q is in the form of a
gas and it is as a gas that the fuel counterflows backwardly
through chamber O as indicated in FIG. 6. Thus it will be
understood that all that is visible when vaporizing or gasifying
heat has been achieved is a ring of blue flame jets T, and an upper
facing disc of such jets at the principal burning zone generally
designated 76, such disc being horizontal in virtue of the
generally right-angular disposition of the inner burner tube to the
head J.
When the burner is up to vaporizing heat, the maximum temperatures
tested on the upper plate 34 have been 1,100.degree.-1,200.degree.
F. However the normal operating temperatures, reached in 2 to 3
minutes at this place are 700.degree.-800.degree. F. Between
approximately the limits of bracket 78 (FIG. 1) maximum recorded
temperatures have been 1,200.degree.-1,400.degree. F. and between
approximately the limits of bracket 80 they have been
1,200-1,400.degree.C F. However, the normal operating temperature
approximately between the limits of brackets 78 and 80 are
850.degree.-1,000.degree. F. and 1,000.degree.-1,100.degree. F.
respectively and reached in 2 to 3 minutes as aforesaid. In the
regions of the arrows 82 and 84, on the surface of jacket B maximum
recorded temperatures have been 1,100.degree.-1,200.degree. F. and
900.degree.-1,000.degree. F. respectively, and after 2 to 3
minutes, normal temperatures at these two regions are approximately
900.degree.-1,000.degree. F. and 700.degree.- 800.degree. F.
respectively.
From all the foregoing it will now be recognized that the invented
oil burner is a low-pressure air-aspirating and atomizing burner.
Fuel oil is drawn through the inlet valve of an associated
gear-type oil pump and discharged into the float chamber thereof,
which float chamber contains a float-operated oil return control
valve. From this float chamber a zero pressure regulator is fitted
to the nozzle assembly supply line. A vane-type air pump driven by
an electric motor common to the oil pump provides air at a pressure
of approximately 6 p.s.i. to the nozzle. Oil is lifted to the
nozzle mixing zone by the aspirating action of the atomizing
primary air. As already stated a relatively large nozzle is
employed. The primary air-oil mixture passes through a horizontal
preheating and vaporizing zone being that which has already been
described in detail and illustrated in the accompanying drawings
before being deflected by a 90.degree. elbow (the angulation
between A and J) to discharge across a diffuser plate, or as
heretofore designated, the plates 34 where it is ignited.
.[.Secondary combustion air.]. .Iadd.The tertiary air stream 66
.Iaddend. is drawn in concentrically at the aperture .[.30.].
.Iadd.26 .Iaddend.as also already described, about the burner tube
A to counterflow chamber O.
In tests, two water heaters fired by the described burner were
employed. Efficiency was determined using the indirect method,
namely by establishing an analysis of the flue gases. The apparatus
used was the standard Orsat apparatus capable of measuring the
CO.sub.2, CO and oxygen in flue gases to a volumetric accuracy of
better than 0.2 percent.
Since the Orsat apparatus could not indicate CO of less than 0.1
percent by volume or about 1,000 p.p.m. a more accurate check using
Bacharach Industrial Instrument Co. CO Tester was carried out. The
results of testing indicated only traces of CO, in the order of 1
p.p.m.
The fuel used was standard Esso Furnace Oil ASTM Specification
D-306 Grade No. 2 distillate fuel.
For each of the two heaters tested the apparent variation in
efficiency was found to be well within the possible errors involved
in measurement and computation of such efficiency. The variation
was less than one-half of 1 percent from the average. The average
efficiency computed for heater No. 1 was 83.8 percent and for
heater No. 2 was 83.04 percent. Combustion was found to be complete
and evidenced by the practically imperceptible traces of CO in the
exhaust gases. The gases expelled are CO.sub.2 and water vapor with
traces of SO.sub.2 and SO.sub.3 depending on the fuel used. The
exhaust gases also were clear and contained no visible smoke or
sooty deposits. Here follows the results of the flue gas analysis
and the evaluated efficiencies in respect of heater No. 2:
11:04 11:15 11:30 13:05 13:30 Test Number (d) 1 2 3 4
__________________________________________________________________________
Flue gas analysis; (e) percent CO.sub.2 10.6 10.2 10.4 0.8 O.sub.2
6.8 7.8 8.2 7.8 CO <0.1 <0.1 <0.1 <0.1 Temperatures
.degree.F. Ambient .sup.(1) 70 72 77 73 Stack .sup.(1) 390 390 400
400 Water in .sup.(1) 46 46 46 46 Water out .sup.(1) -- 140 140 142
Excess air percent .sup.(1) 45.3 56.3 61.7 55.9 Flue gas loss
percent .sup.(1) 8.34 8.52 8.53 9.07 Comb. H.sub.2 O loss percent
.sup.(1) 7.20 7.19 7.19 7.21 Air H.sub.2 O loss percent .sup.(1)
0.14 0.15 0.15 0.15 Other loss percent (a) .sup.(1) 1.0 1.0 1.0 1.0
Calculated efficiency percent 83.32 83.14 83.13 82.57 Average
efficiency 83.04 83.04 83.04 83.04
__________________________________________________________________________
.sup.1 Start up of second unit.
In the above table (a) means other loss taken as radiation plus
unaccounted for loss, assumed at 1 percent: (d) heater run
continuously from startup. Water flow approximately 3.75
lb./minute: (e) Orsat Apparatus accuracy better than 0.2 percent
volumetric.
Reverting in conclusion to the burner as exemplified, there is
shown in FIG. 7 a means for causing the flame of tongue Q to be
extinguished when a sufficient rise in ambient temperature has
supervened. The circuitry shown is purely exemplary and not that
which is actually used since the circuitry actually used is
considerably complicated beyond what has herein been shown having
regard for other purposes such as demand startup, safety controls
and the like common to oil burner installations. The circuitry of
FIG. 7 is however sufficient to indicate a means for the precise
purpose just stated and it is to be understood that the same will
be housed within the control box 86 from which, or adjacently from
which projects a conventional probe 88 which could also be adapted
for use as the means for causing the flame of the tongue to be
extinguished under the circumstances just mentioned, both the
utilization of the probe for such a purpose and the circuit of FIG.
7 being well within the skill of those versed in the art to which
this invention pertains.
With the foregoing understood, a grounded heater coil 90 is
provided on one side of the electrode circuit 92, as an element in
the series circuit 94. A shunt 96 to one of a pair of terminals 98
and 100 is located in the shunt circuit 96. A bimetallic strip
thermostat 102 is connected in the circuit 94. When the heater coil
deflects the thermostat from the position shown and out of contact
with terminal 98, circuit 92 is interrupted and the electrode H
inactivated. As a consequence the visible tongue of flame is
quenched in favour of the condition which has already been fully
described herein.
Various modifications can be made within the scope of the inventive
concept disclosed. Accordingly, it is intended that what is set
forth herein should be regarded as illustrative of such concept and
not for the purpose of limiting protection to any particular
embodiment thereof, and that only such limitations should be placed
upon the scope of protection to which the .[.inventor hereof.].
.Iadd.patentee .Iaddend.is entitled as justice dictates.
* * * * *