US1674282A - Oil burner - Google Patents

Description

June 19, 1928.

FLETCHER on, BURNER Filed Juiy 23,` 1926 3 Sheets-Sheet .hullllllllllllllrl June 19, 1928. 1,674,282

G. v. FLETCHER OIL BURNER Filed July 23, 192e -'sheets-sheet 2 June 19, 1928.

. 1,674,282 G. V. FLETCHER OIL BURNER Filed July 23, 1926 5 Sheets-Sheet 5 jig. .7

v Patented June 19, 1928.

, velocity.

l UNITEDKSTATES PATENT OFFICE.

GEQRGE lVAUGHN FLETCHER, OE MINNEAPOLIS, MINNESOTA.

' oIL BURNER.

' Application filed July 23,

' My invention relates to oil burners of the type wherein the atomizati'on bf oil isproin like characters indicate like parts throughlv out the several views.

Referring to the drawings:.

Fig. 1 is a vertical section of the burner, showing the sameapplied `to a boiler or furnace, someparts being broken away', some parts being shown in full, and some parts being sectioned on the line 1- 1 of Fig. 2;

Fig. 2 -is av plan'view of the burner, .some

yparts sectioned von the line 2-2 of Fig. 1, and

some parts being broken away;

Fig. 3 is a side elevation of the burner, some parts being broken away;

Fig. 4 is an enlarged section taken on the line 4 4 of Fig. 1; and Fig. 5 is a fragmentary section on the line 5-5 of Fig. 2.

In Fig. 1, the numeral 5 indicates a boileiner furnace having the customary ash pit 6, but provided with an annular supporting plate 7 substituted for the grate and covered with an' insulating material 8, suchv as concrete. In the preferred mann r of installing the burner, the plate 7 and insulation 8'closely surround the upper portion of a large cup-like air trunk 9 into one "sidexof which air is blown through an air, intake pipe 10 'that is' connected to the discharge spout 11 of a power-driven fan or blower 12. The case of this blower 12 is mounted on a base 13, which is preferably a cast struct-ure provided outside of the 'furnace with a laterally extended ground-engaging por/tion 14. Preff erably, therota'ry head ofthe blower 12 1s driven from a small electric motor 15 supported on the base 13. They inner end portion of the base 13 is adjustably supported by a screw-threaded leg 16 and the air trunk 9 is adjustably supported on :tl' inner port-ion' of said base by screw-threaded supporting legs 17, which adjustable features make 1t 1926. serial No. 124,436.-

an easy matter to set the air'trunk 9 and Vthe bowl supported thereby and presently to be described in a true level position and at the proper altitude. l

The numeral 18 indicates a ycombustion bowl, preferably a cast structure having an outstanding rim ange 19'that rests on the upper edge of the air trunk 9, forming a close joint therewith. Also, the bowl, immediately adjacent its supporting flange 19,`

has a Short cylindrical portion 20 that telescopes into the air trunk 9'Y and keeps the lower portion of the. bowl concentrica-lly spaced from theI walls thereof, so that the air inthe trunkran sweep completely around the bowl below said cylindrical portion 20.

, At a plurality of points, as shown at four points circumferentially spaced, the bowl 18 isforinedpvith air intake ports 21'and 21a. The port 21a has considerable length/cir cumferentially of the bowl and will direct thel air delivered,therethrough against the peripheral wall of the bowl, vcausing the same to directly take up a whirling motion against the inner surface of the bowl. The oil or fluid fuel will be delivered into this port 21 and', hence, the bottom of said port is inclined toward the interior of the bowl so thatl surplus oil will not run out of the bowl. fThe ports .21, of which, 'as shown, there are three, openfsub'stantially taugen tially into the bowl, but they are cut or formed so that lthey do' not have thevsame tendency to cause the air to hug the peripheral "wall of the bowl, but lrather tend lto direct the air spirally inward and toward the axis of the bowl. The-important action produced by these cross currents will be further considered in the descriptiolLof the. operation. 4 A j -v The numeral 22 indicates a. drain pipe or tube applied to theibottom and depending from the center of the bowl. The upper portion of the bowl is formed as a separate annular ele1nent'23tl1at is contracted. This portion 23 vwill be subjected to they most intense heat and, it being separately formed, may7 be made of carborundum or other material that is more highly refractory thanf` the cast body of the bowl.- Even when the upper rim portion 23 of the bowl is ofcast iron or steeLit should be formed separately from the bowl so that it may be readily to the body of the bowl, it'fis` shown as rabbeted at its lower edge and made to loosely fit a correspondingly rabbeted' portion of the bowl, as at 24.

In this preferred arrangement, the oill or -fluid fuel is delivered to the air intake port 2l through a pipe 25 that is extended 'l through the side "of the air trunk 9 and is tapped through the side of the bowl so that itidelivers .the oil at the very top of said any suitable'source, such as an elevated tank or `pump, so far as this invention is concerned. Y

In connection w1th an oil burner if this character, a pilot. light, suchI jas a small gas yilame maintained within the bowl for effect- `ing initial combustion of the 'oil vapor, is

desirable; and this pilot is preferably arranged as'follows: A small gas pipe 27 is extended through and spaced from the walls of .the drain pipe 22 and at its lower end is screwed into acoupling 28 shown as secured' to 'and vdepending from`the bottom of the air trunk 9 by threaded enga-gement at `29. This coupling 28 has two compartments 30 and 31. The lower end of the gas pipe 27 leads upward from the compartment 30 and the lower endof the drain pipe 22`extends' .downward into the open -upper portion of the chamber 31 but'is spaced from the 'walls of the latter so. that said chamber 31 affords a drain from the bottom of the air trunk.

Elbows 32 and 33 are screwed into the coupling 28 and communicate, respectively, with the chambers 30 and 31. 'A gas supply pipe 34 leads to the elbow 32 and a drain pipe 35 leads from the elbow 33 to a suitable point of discharge.l A pilot head 36 is applied to the upper endof the gas pipe 27, as shown, vby threaded engagement, and is provided with a plurality ofl downwardly sloping gas discharge passages 37 that directs the plurality of pilot flames onto or immediately above the bottom of the bowl.

Summary of operation.

When the blower is in action, air pressure will be produced in the air trunk 9 and air from `said trunk will be discharged into the bowl through the several tangential air ports 21-21. thus delivered into the bowl will set up a. violent whirling orv cyclonic action within the bowl and the air inthe air trunk sur- The several streams of airy roundingthe bowl will also be caused to' whirl .to some extent thereby insuring an even supply of air through the several air ports.

The oil delivered into the bowl from the fuel pipe 25 will be primarily taken up by the air introduced into the bowl through the port 21a. The air-introduced into the bowl through the port 21a will be directed against the -wall ofthe bowl and, under the action of centrifugal force, will tend to hug the wall of the bowl and revolve therein with an upward spiral trend. The'air delivered into the bowl'through the several ports 21 will also be given a spiral rotary movement within the bowl, but the air currents thus introduced will have a trend toward the axis'of the bowl, so that they will cut through the whirling oil-laden air blast introduced through the port 21a. .These cross currents or currents having the greater inward trend break up or tend to break up the primary spiral oil-laden current, thereby producing a thorough intermingling of the several cur rents and a turbulence of air currents'that insures the most complete atomization of theH oilv and most thorough commingling of the oil and air. Moreover, the inward trend of the disrupted cross currents introduced through the ports' 21 very greatly improves the action of the burner, not only generally 'but particularly at the center of the bowl, where there will be a tendency to more or less incomplete combustion, resulting in some ultimate accumulation of carbon at the center'of the bowl, whereas, with the arrangement described, such incomplete combustion and accumulation of carbon is eliminated.

Of course, centrifugal force will keep a greater part of the whirling oil-vapor-laden air whirling against Vor close to the wall of vthe bowl so that the ultimate yupward discharge thereof from the bowl will be retarded by the contraction ofthe rim` portion of the bowllong enough to cause a most complete vaporization of the oil. The combusf tion wll be started within the bowl, but the flame and the complete combustion will take place above and outside of the bowl. Cen* trifugal force, acting on the whirling vaporladen air, will cause an expansion of the flame into a cup-shaped or saucer-shaped flame immediately upon its discharge or `release from the rim of the bowl, with the re sult that the flame produced will be properly' spread for the most complete combustion and most effective -heat production.

It will be noted that-the` pilot throws a. plurality of flames ,radially outward from the center` of the bowl and that the commingled air and oil are caused to whirl around the pilot in such manner that quick ignition is insured and there is a minimum of tendency to blow out the pilot flames.

llO

I Vhen the burner is in action, the air laden with oil or vapor in the proper mixture for combustion will, as already indicated, be discharged from the top of the bowl in an annular out-spreading blast. Tests have shown that, at such time, there will-be a flow of hot air from the combustion chamber' axially downward into the bowl. This downwardly flowing stream of hot air, upon entering the bowl, is also caused to rotate and, as it spreads, will commingle with or act upon the vaporized oil and further assisty in the final and more complete atomization thereof, so that the oil vapors will reach the flashing pointas they are discharged from the bowl.

The eiiicieney of this comparatively simple burner has been thoroughly demonstrated in practice and the statements herein made are based on actual experience and tests in the use .of the burner. A

IVhatI claim is:

l. In an oil burner, a combustion bowl having a. plurality ot'v peripheral circum-l ferentially spaced air intake port-s, means for introducing air into said bowl through said ports, thereby setting up a whirling motion of the air within the bowl, and oil delivery means opening directly into at least one of said ports that is4 located between certain other of the air ports, into which latter oil is not delivered. i

2. The structure defined in claim l in which the air port into which oil is delivered has a bottoni that inclines toward the interior of the. bowl. Y

3. An oil burner comprising a cup-like air trunk, a blower connected to Said air trunk, a. bowl detachably mounted on the rim of said air trunk and depending thereintobuti, spaced from the sides and bottom thereof,

u' said bowl having peripheral air intake means for delivering air from sald trunk vinto said bowl and setting up a. whirling motion of the air in the bowl. and a separately formed rim portion 'detachably mounted on said bowl.

4. The `l`structure defined in claim 3 in which said detachable rim portion is contracted toward its upper edge.

5. In an oil burner. the combination with a bowl having a plurality'of peripheral circumfercntially spaced air intake ports. means for introducing air into` the bowl through said ports. thereby setting up a whirling motion of the air within thebowl,

and an oil delivery port opening directly said air intake ports.

6. The structure defined in claim 5 in which said bowl has a wall portion below the oil intake port and over which the oil will run from said port toward the bottom of the bowl while it is being acted upon by the whirling air. i

T. In an oil burner an air trunk, means for deliveringl'air into said trunk, a bowl set into said trunk and having peripheral air intake ports for delivering air from said trunk into said bowl and causing the same to whirl within the bowlfmeans for delivering oil into said bowl, whereby it will be taken up and vaporized by the air whirling p into the upperportion of at least one of'v within the bowl` a two-compartment coupling applied to the bottom of said air trunk and formed with gas and oil` chambers, the

a. gas supply pipe leading to said gas charnber, a. gas pipe extended upward from said gas chamber and provided with a delivery head located Within the bowl, a ydrain pipe surrounding said gas pipe and extended from the bottom of lthe bowl into the oil latter opening into the bottom of said trunk,

through the whirling air current first noted and with a greaterv trend toward the axis of the bowl, and means for introducing oil into the bowl where 'it will be taken up and vaporized by the whirling air wit-hin the bowl.

9L In an oil burner, a combustion ybowl having afplurality of peripheral air intake ports, at least one thereof being arranged to introduce the air substantially tangentially and at least one of said ports being ar' ranged to introduce V air into the bowl through the whirling air current first noted and with a greater trend toward the axis of the bowl, and means for introducing oil into said bowl at the first noted air intake port.

In testimony whereof I aliix my signature;

GEORGE VAUGHN FLETCHER.

Images