US1681778A - Combined mixing and combustion chamber for liquid-fuel-burning apparauts - Google Patents

Description

Aug. 21, 1928. 1,681,778

c. A. OLSEN COMBINED MIXING AND COMBUSTION CHAMBER FOR LIQUID FUEL BURNING APPARATUS Filed July 19, 1926 2 Sheets-Sheet 1 ,ln' Q N s Q Q @TZ a. aheia mew/$072- I y I /7z)ve7t'0 7; 1 a iarZ a. 0Zse7z I \1 I 3y fi ud 6 4% Aug. 21, 1928. 1,681,778

' c. A. OLSEN COMBINED MIXING AND COMBUSTION-CHAMBER FOR LIQUID FUEL BURNING APPARATUS Filed July 19, 1926 2 She ets-Sheei. 2

Patented Aug. 21, 1928.

UNITED STATES CARL A. OLSEN, onLYNn, MASSACHUSETTS, ASSIGNOR, BY YMESNE ASSTGNMEN S, To A T OIL BURNER, so, or LYNN, MASSACHUSETTS, A CORPORATION orM'AssAcHU- I snTTS.

1,681,778 PATENT OFFICE.

COMBINED MIXING Ann COMBUSTION CHAMBER ron LIQUID-F EL-BURTTING A APPARATUS.

Application filed July 19, 1926. Serial No. 123,562.

This invention relates to liquid fuel burning apparatus and more particularly to a combustionchamber attachable thereto.

It is an object of the invention to surround the flame end of a burner with a combustion chamber wherein a completev mixture of the fuel and air takes place, and consequently perfect combustion obtained, before the flame Kits into the fire box proper of a heater.

Otherobjects of the invention will be fully understood from a description of the drawings and the claims hereinafter given.

Of the drawings:

Figure 1 represents a side elevation of one form of liquid fuel burning apparatus having the invention applied thereto.

' Figure 2 is a right hand elevation of Figure 1.

Figure 3 is a vertical "lingitudinal section of a portion of the burner at the tip thereof.

Figure 4: is atop plan view of a portion of the burner tip shown inFigure l.

Like characters represent like parts throughout the several figures of the drawings. V

Referring to the drawings.

The drawings herewith illustrate an improvement on an application filed July 20, 1925, Serial Number 14,777, wherein generally speaking the burner consists in a motor M, a blower B, a pump P, a turbine end or burner tipportion T, a pilot L, and a fuel cut-off mechanism F, each of which is directly or indirectly supported on a base 10.

It will be understood however that the invention might be used on other types or makes of burners, and therefore its construction and arrangement might be changed without de parting from its spirit and scope.

The motor Mmay be of any usual or suitable type and power for the work required, and has coupled therewith ablower or fan B also of suitable make and capacity, and the pump P of preferably rotary type.

The fuel tank or container, not shown, is preferably so situated as to feed the fuel level regulator 12 by gravity through the pipe 13, valve 14 and pipe 15, the said regulator being so located as to contain a uniform level of fuel therein, and consequently a uniform head or pressure of fuel is maintained from which the pump 1? draws its supply. g

Leading from the regulator 12 is a pipe 16 connecting with a T fitting, one branch of which 17 leads to the pump P, and another branch 18 leads to the pilot L which may be of any usual or suitable construction.

From the pum P a pipe leads having a valve fitting 20 acapted to control the flow-of fuel through the pipe 21 to the turbine at the burner tip T. v

In the present instance theburner tip T is located at the end of a pipe 22, which leads from the blower B, and comprises a spider like frame 23 arranged to provide bearings for a shaft 25 on one end of which a fan like propeller 82 is mounted, its opposite end having aspider like support 37 to which issecured the fuel breaking or distributing cup 88.

The fuel cup 88 is fed by a pipe tapped into a chamber 14: in said frame 23 into which a fitting 41 connecting the pipe 21 also taps.

Upon starting the motor M the blower B will immediately begin to force air through the pipe 22 gradually at first and increasing in volume and pressure as the maximum speed of the motor is reached.

Simultaneously the pump P will begin to force fuel through the pipe 21 towards the burner tip Tby way of the pipes 21 and 45 into the cup I88, which is rotated by air under pressure in the pipe 22 contacting with the propeller 32.

After leaving the propeller 32 the air passes through the pipe 22 and spiderlike frame 23 being deflected by the annular member l7 which compels it to pass externally of the cup 38, and between it and the nozzle 50, which is provided witha plurality of holes adjacent its mouth. I

Therapid rotation of the cup 38 causes'the fuel to leave it in an extremely thin film which however is broken up as it leaves by centrifugal action, and its meeting with'the air blast from the nozzle 50.

Under some conditions of air pressure and specific gravity of fuel used, centrifugal action on the fuel. upon leaving the cup 38 would have a tendency to cause the fuel to break through the surrounding film of air to lodge on the walls or bottom of the fire box of a heater to be later ignited and causing an explosive noise not necessarily dangerous but at least unpleasant and nerve racking, and unsatisfactory as regards the efficiency of the burner, y

It is an object of the present invention to overcome any such tendency as well as to catch and direct into the flame all fuel which may drip from the cup 38 at the time of starting the burner into operation which latter often occurs before the burner is lighted and has attained its maximum of efiiciency.

It is also an object of the invention to provide means to accomplish the last mentioned results and to provide a chamber in whichthe fuel and air are mixed and ignited before the flame therefrom exits into the fire box proper of a, heater.

The means provided is a simple one consisting in a member a of fire brick clay or other suitable material arranged to receive the burner tip T, and the free end of the pilot panQO as best seen in Figures 3 and 4 of the drawings, the said member has a chamber Z) of comparatively short length but which serves to confine'the combustible mixture to. a sufficient extent to ensure the ignition thereof before leaving the chamber and entering the fire box of the heater.

The said member a not only confines the combustible mixture but it serves as a mixing chamber in which a circular film of air surrounds the fuel exit of the cup 38 and breaks up the Whirlingradially moving film of fuel when it leaves the mouth of the said cup, and carries it with itself up to the point where both merge into flame.

To further aid in causing a proper mixture of the fuel and air, the nozzle is provided with radiall r and an 'ularl arran ed holes 50 through which air from the pipe 22 escapes and is directed to the wall of the here: or hole forming the chamber. 6 so that any fuel which might break through the film of air emerging from between the cup 38 and the inner wall of the nozzle 50 and lodges on'the wall of the chamber 6 will be picked up by it, mixed therewith, and carried into. the flame to be consumed. I I

Both the combustion chamber and the arrangement of the air openings in the nozzle cooperate with the pilot light in order to en'- able use of a light of this character which is economical andyet reliable andefficient in operation. The combustion chamber is preferably formed of refractory, somewhat absorbent material, such as fire-clay, which tends to catch any fuel which is cast outwardly through the .main air draft, and which, due to its high temperature, aids combustion of the fuel. Thus, at the instant when the main burner is shut off, the: fuel which has been cast upon the hot wall of the combustion box continues to be vaporized and ignited to provide a comparatively slow burning flame in the region of the pilot, which will serve to relight the latter, if it ha'sbeen accidentally extinguished due to the action of the main air draft. The use of fairly thick slabs of fire-clay or similar material having low heat conductivity provides considerable heat insulation and permits the region immediately surrounding the burner tip to remain at a comparatively high tem perature, although'the pilot light may be comparatively small and may require but little fuel. When the main burner tip and air draft are again started, the air passing outwardly through openings 50* provides an additional supply of oxygen for the pilot flame, permitting an increase in the scope and intensity of this flame so that quick ignition of the oil coming from the burner cup results. I Furthermore the combustion :box which surrounds the burner nozzle protects the pilot flame and prevents thesame from being bent orflattened out by the main air draft or being affected by the back draft which results from the drawing of air into the current of the main air draft. lVithout the combustion box a much larger pilot flame is accordingly necessary to insure ignition of the main burner. Thus it ispossible to utilize a small pilot flame with consequent economy in operation and yet to maintain the region surrounding the nozzle at a sufficiently high temperature and also to provide a flame of suitable size to insureinstant ignition of the main fuel supply when the same is again started. V i

It will be understood that certain features of the above application have been mentioned herein which do not form part of this invention, and will not be specifically claimed herein, as for instance the pilot and fuel cut-off means, and in fact the burner tip may be of any usual or suitable construction so long as fuel and a combustion aiding agent emanates therefromfor the purpose of mixing to form a combustible mixture. v I I Having described the invention I claim:

1. A liquid fuel burning apparatus comprising a burner tip; means to supply fuel to said tip means to supply air under pressure to said tip; a pilot; a combined'mixing and combustion chamber arranged to surround a portion ofsaicl tip and 'said pilot and to extend a substantial distance therebeyond; said tip having a fuel exit; a nozzle forming part of said tip and surrounding 'said exit and through which air under pressure passes into said chamber, said nozzle having air passages adjacent its-mouth whereby air is directed against the wall of said chamber to thereby pick up and mix with stray portions of fuel which may have broken through the film of air emanatlng from the mouth of said nozzle so that all the fuel entering said chamber may be carried into a flame emanating from said chamber.

2. A liquid fuel burning apparatus compilot; a combined mixing and combustion chamber arranged to surround the mouth of said nozzle and a portion of said pilot, and to extend a substantial distance therebeyond; said nozzle having radially and angular-1y arranged holes adjacent its mouthand arranged to direct air against the wall of said chamber whereby fuel lodging on said wall will be mixed with and carried by said air into a flame emanating from said chamber to thereby effect a combustible mixture and consumption of all the fuel entering said chamber.

3. A liquid fuel burning apparatus comprising a rotary burner cup, means to supply fuel to said cup, means to provide an air draft about said cup, and a combustion chamber of refractory material extending outwardly a substantial distance beyond said cup, said combustion chamber having the inner sur faces of its walls extending outwardly in substantially the same general direction as that of the axis of cup rotation, the bottom of said combustion chamber extending outwardly further than the top thereof to provide addi tional means for catching fuel, whereby fuel thrown outwardly through the air draft by the cup is caught in a region having a temperature high enough to insure its combustion during normal operation of the device.

4. A liquid fuel burning apparatus comprising a rotary burner cup adapted to cast fuel outwardly, a nozzle surrounding the cup and adapted to direct an air draft outwardly about the cup, openings adjoining the outer end of the nozzle arranged to divert a portion of the air outwardly into a region about the nozzle to aid combustion of fuel. that is thrown through the main air draft, and a combustion box extending an appreciable distance beyond the end of the nozzle and having its walls arranged to aid the combustion resulting from the combination of fuel thrown through the main air draft with air diverted through the nozzle openings. I

5. A liquid fuel burning apparatus comprising a rotary burner cup, adapted to cast fuel outwardly,a nozzle surrounding the cup, and adapted to direct an air draft outwardly past the cup, openings in the nozzle adjoining the outer end thereofto divert a portion of the air outwardly into a region about the nozzle to aid combustion of fuel that is thrown through the main air draft, a pilot adapted to project a pilot flame in the vicinity of the end i of the nozzle whereby the air cast outwardly from the nozzle openings may augment the scope of the pilot flame when the air draft is initiated, and a combustion box of refractory, somewhat porous and adsorbent material extending around the pilot and nozzle, said box having walls extending outwardly a substantial distance beyond the open end of the nozzle to catch the major port-ion of the fuel that is thrown through the main air draft and so that the air diverted through the openings in the nozzle will impinge thereon.

6. A liquid fuel burning apparatus comprising a rotary burner cup adapted to cast fuel outwardly, a nozzle surrounding the cup and adapted to direct an air draft past the cup, openings in the nozzle adjoining the outer end thereof to divert a portion of the air outwardly into a region about the nozzle to aid combustion of stray fuel particles that are thrown through the'main air draft, and a.

combustion box of refractory, somewhat porous and adsorbent material extending a substantial distance beyond the end of the nozzle and having its walls arranged to receive the stray fuel particles thrown through the main air d "aft and to permitcombustion upon their inner surfaces resulting from the combination of the fuel particles thrown through themain air draft with air diverted through the nozzle openings. 7

7. A liquid fuel burning apparatus comprising a rotary burner cup, means to supply fuel to said cup, a nozzle surroundingthe cup, means to provide a main air draft through said nozzle and past said cup, a combustion chamber with a wall of refractory material having the inner surfaces of its walls extending outwardly to such a distance beyond the cup that said surfaces will be cut by a cone having its apex at the open end of the cup, its axis aligned with the axis of the cup and its side forming a 60 angle thereto, and a plurality of angularly disposed openings in said nozzle adjoining its open end, said openings being arranged to divert a portion of the main air draft so that air flows outwardly through the openings against the inner surfaces of the refractory wall of the combustion chamber.

Signed by me at Lynn, Massachusetts, this llth day of July, 1926.

CARL A. OLSEN.

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