US2039607A - Liquid fuel burning apparatus - Google Patents

Description

May 5, 193'6. M. A.' POWERS 2,039,607

LIQUID FUEL BURNING APPARTUS Filed July l, 1932 Patented May 5, 1936 LIQUID FUEL BURNING APPARATUS Milton A. Powers, Detroit, Mich., assignor to The Timken Silent Automatic Company, Detroit, Mich., a corporation of Michigan Application July 1, 1932, Serial No. 621),'373

18 Claims.

My invention relates to liquid fuel burners of the so-called rotary wall flame type wherein ignition and combustion take place around the outer periphery of a hearth adjacent to the wall of the combustion chamber of the furnace. It has for its principal objects to reduce to a minimum the time elapsing between initial ignition and the obtaining of normal combustion conditions, to enable the burner to properly consume a heavier and less costly fuel than has heretofore been practicable, to expose a larger area of heat absorbing surface to the heated gases, to

minimize the deleterious eifects of the highly heated combustion member of the present conventional type after shut down of the burner, to simplify the method oi'. burner installation and to reduce its cost, and to lengthen the life s"pan of the hearth. Other objects and advantages will appear hereinafter.

'The invention consists principally in providing the hearth of such a burner with a peripheral ignition and combustion ring spaced away y from the furnace wall and made of metal or other heat conducting material. The invention further consists in the ignition and combustion ring for liquid fuel burners and in the parts and combinations and arrangements of parts hereinafter described and claimed..

In the accompanying drawing which forms part of this specification and wherein like numerals refer to like parts wherever they occur,

Fig. 1 is a plan view of a portion of a furnace .having an ignition and combustion ring embodying my invention;

around the periphery of saidv hearth. O11 andairare discharged from said distributor head, the outwardly moving particles of oil being for the most part above the level ofthe air current.

The hearth periphery construction prior to my invention has consisted usually of a ring built up of a plurality of segments of refractory clay material placed against the water leg or combustion chamber wall and extending around the periphery of the hearth.

Fig. 2 is an elevation at the jointbetween two As illustrated in Fig. 4 my ignition and combustion ring comprises an upstanding supporting wall portion 8 near the outer periphery ofthe hearth and spaced a short distance, say three or four inches, away from the wall l of the com- 5 bustion chamber, an outwardly extending ledge S at the top of said supporting wall having a groove or gutter I0 therein, and an upwardly extending impact wall portion Il disposed at the outer edge of said gutter and terminating in a lo substantially vertical upper edge flange I2. Said ring is preferably made of heat resisting metal and is of comparatively thin section.v

Preferably the combustion ring is made in segments I3 which may be partly assembled out- 15 'side the combustion chamber, with final assembly in place to form a substantially continuous hearth ring.

Figures 2 and 3 illustrate a suitable clip member i4 for supporting the abutting ends of adja- 20 cent segments i3 and at the same time spacing' the segments the desired distance from the ccmbustion chamber wall The clip i4 illustrated includes a supporting body member i5 of contour similar to that of the segments i3, Said body 25 or chair member has spaced lugs it at the top and similar lugs il at the bottom, which be bent to clasp the top and bottom portions respectively of the metal segments i3. A vertical backing brace it attached to the chair i5 as by 3@ welding at spots i9 has a base 2@ that rests on the hearth and may be provided 'with a downwardly projecting-anchor portion 2l for embedding in the hearth 2 while it is still plastic. The outer end of the'backing brace it abuts against 35@ the furnace wall and suitably spaces the segments from the wall.

In assembling two segments i3, the procedure is to slip the lower edges of the segments behind the iower lugs n with the abutting ends or the .to

'N0s. 1,888,692, 1,888,694 and 1,888,695. spaced electrodes 22, 23 are mounted in a combustion ring segment 2li composed of refractory clay vor other suitable material. As the tace of this igniciently high to instantly vaporize the oil. Air e from the distributor head I flows along the hearth surface as shown at A and is deflected upward by the lower or supporting wall portion 8 of the combustion ring and flows over the edge flange I2, where it entrains vapor arising from C and mixes with it above the level of the top surface -of the combustion ring, where combustion is initiated, the shape of the flame being illustrated and being indicated by the letter F. Instead of burning entirely above the top of the combustion ring (as in the case of the normal flame of previous burners having a refractory clay ring abutting against the furnace wall), the flame extends down into the space between the impact wall I I and the furnace wall 4 and highly heated gases and ame make wiping contact with the outerface of the thin metal impact wall I I. Thus the impact wall is quickly heated to its maximum temperature, said maximum being considerably higher than that of a refractory clay member.

It follows that there is almost -no delay in transmitting a large amount of heat to the-oil as it strikes the impact wall; so that complete vaporization takes place within a very short time from the instant of starting the burner.

When starting the burner in a cold boiler, oil strikes the impact surface C, wetting it and drainl ing down into the gutter E where it collects. The oil in said gutter is ignited and the name is at v once propagated around the gutter E and continues to burn in said gutter until the rate of vapor formation is suiliciently high to produce an over-rich mixture in the gutter, at which time the flame moves upwardly to the topof the impact wall and burns thereafter at this upper level.

With my construction, all impinging oil is being vaporized and burned in less vthan twenty seconds 5I) face of the metal combustion ring is dry. The

from the starting of the burner in a cold furnace and in less than forty-five seconds the entire surrapid heating of the combustion ring prevents the accumulation of oil in the gutter.

The almost instantaneous heating of the impact wall and its continuous heating thereafter by reason of the flame contact with the outer 'surfacethereof makes it possible to use oils that are quite heavy and have a high end point. Th'e very rapid heating of the impact wall and `of the entire combustion ring, the high ilnal operating temperature and the concentration of a llarge amount of heat at the vaporizing zone make possible the burning of a heavy oil, such as oil of the No. 3 grade or even somewhat heavier oil. In using the lowest grades of oil, a small amount of carbon may collect at the point of impingem'ent.

but as soon as this reaches any appreciable thickness, flakes drop foif into the gutter where combustion conditions are such that-these akes of carbon are entirely consumed.

The spacing ofy thecombustion ring a slight distance away from 'the boiler wall allows the flame and highly heated gases to wipe the boiler wall to the levelofthe top of the hearth H, thus making available as a heat absorbing surface Y boiler.

i -aosaeov me eddiuenn aree indicated by the' letter r. rms distance is approximately two inches, or over ten percent ofthe eifective height of the usual ccmbustion chamber of not to exceed twenty inches in height. -The ignition and burning of part of the normal flame in'thev protected channel between the combustion ring and the boiler wall causes the name to hold down to the desired location instead of lifting upwardly into the 'I'he metal segments are of light weight and may be nested together, thereby greatly increasing the economy and convenience of handling and shipping. Being made of metal, the segments can be held within very close tolerance limits as to all dimensions, whereas segments made of other materials necessarily vary considerably in dimensions. Making the segments of metal minimizes the loss and waste of material and parts v throughout the processes of manufacturing, hanfurnish replacement parts. Installation of themetal segments is quite easy, as` a number of them may/'be assembled outside the furnace, slipped through the ilre door ontol the hearth and the clamp members then locked in place if required. 'Ihe segments may b e made of any desired heat resisting metal, such aschrome-nickel 5 steel or chrome steel having at least twelve. percent chromium content. l

'I'he present combustion ring is especially suited for the increasingly popular and desired installation in hot water and steam boilers provided with an indirect water heater, such installations having heretofore mede considerable trduble due te the fact that in warm weather the periods of operation required to heat water for domestic use are too short to enable'prior constructions to reach normal operating conditions, thus causing accumulation ,of' oil and tarry matter, smoky i flame and other important disadvantages; whereas my combustion ringprovides the quick heating of the combustion ring and the high final operating temperature essential to the truly satisfactory and efficient operation'of such devices.

The present construction is also rapid in its cooling aft'er the burner has shut down,A thus avoiding the possibility that restarting may take place while the hearth is still heated, with the result that the immediate and complete vaporization of the fuel would blanket the ignition device and cause a highly undesirable and dangerous delay in ignition.

Obviously, numerous changes may be made without departing from the invention and Ido not wish to be limited to the precise construction shown.

What I claim is: 1. `Liquid fuel burning apparatus of the rotary wall llame type comprising a combustion chamber havingaI peripheral wall, a vaporizingand carbureting structure comprising a troughed step member of imperforate sheet material of high heat conductivity having an upwardly extending impact wall portion along its outer margin` spaced away from said wall, centrifugal means for spraying oilv against said impact wall portion and means for directing a current of air towards .said

troughed step member, said air current being deflected upwardly by said step member.

2. A hearth construction for liquid fuel burners of the wall iiame type wherein oil and air for combustion are.discharged from a centrally located rotary head, consisting of a substantially flat bed of refractory hearth material extending to the periphery of the combustion chamber and a continuous segmented sheet metallic peripheral ring resting upon said hearth bed near the periphery thereof.

3. A hearth construction for liquid fuel burners of the wall flame type wherein oil and air for combustion are discharged from a centrally located rotary head, consisting of a substantially flat bed of refractory hearth material extending to the periphery of the combustion chamber and a substantially continuous sheet metallic ring located 4near but slightly spaced from the sides of the combustion chamber and resting upon said hearth bed.

4. A hearth construction for liquid fuel burners of the wall flame type wherein oil and air for combustion are discharged from a centrally located rotary head, consisting of a substantially fiat bed of refractory hearth material extending to the periphery of the combustion chamber, a substantially continuous sheet metallic ring located near but slightly spaced from the sides of the combustion chamber and resting upon said hearth bed, and means for holding said ring in place on said hearth bed.

5. A liquid fuel burner of the rotary wall flame type comprising a combustion chamber, a hearth extending to the periphery of said combustion chamber, means disposed centrally of said hearth for discharging oil and air toward the periphery thereof and a peripheral combustion ring of sheet material of high heat conductivity spaced slightly from the periphery of said hearth.

6. A liquid fuel burner of the rotary wall name type comprising a combustion chamber, a hearth extending t-o the periphery of said combustion chamber, means disposed centrally of said hearth for discharging oil and air toward the periphery thereof and a peripheral combustion ring of sheet material of high heat conductivity spaced slightly inward from the periphery of said. hearth, said combustion ring having an, air defiecting face projecting upwardly from the surface of the hearth, a gutter in the lee of said deiiecting face and an upwardly extending impact wall at the outer edge of said gutter.

7. In a liquid fuel burner of the wall flame type, a combustion chamber having a hearth and a peripheral wall adjacent to which wall combustion taires place in an annular zone, said hearth serving to close said chamber adjacent said wall, and a1 sheet metal combustion ring spaced inwardly from said wall and in the path of liquid fuel.

8. In a. liquid fuel burner of the rotary wall iiame type, a hearth, a peripheral wall therefor,l a plurality of metal segments extending around said hearth spaced inwardly from said peripheral wall and arranged in abutting relation to each other, and clips for supporting and positioning the abutting ends of adjacent segments and spacing them away from said peripheral wail, said clips having surf aces conforming to the contour of said segments, portions. for clamping the ends of adjacent segments in abutting relation and por` tions for anchoring said clips to said hearth.

9. In a liquid fuel burner of the rotary wall flame type, a hearth, a peripheral wall therefor,

hearth and an upright wall, fuel distributing means designed to project a fuel stream above said hearth and toward said wall, a fuel vaporizing wall spaced materially from said chamber wall in the direction of said fuel distributing means and spaced substantially above said hearth to intersect the path of said fuel stream, thereby.

to form a relatively large chamber between said vaporizing wall and said upright wall of the combustion chamber, and means for supplying and causing air to intersect the fuel stream in the region of said vaporizing wall.

11. In the combination defined in claim 10, said fuel vaporizing wall being thin and formed of refractory material that is a good heat conductor.

12. In a liquid fuel burning apparatus, in combination vwith a combustion chamber having a hearth and an upright wall, and fuel distributing means positioned to project a fuel stream toward said wall, a refractory carbureting structure disposed between said wall and said distributing means and comprising a thin fuel vaporizing wall of high heat conductivity mounted above the hearth in the path of the fuel stream, means for directing air toward said upright wall in the vicinity of said vaporizing wall, and a member for causing the air to mix with the fuel vaporized by said thin wall, said member being spaced horizontally with respect to said thin wall to provide therebetween a. somewhat sheltered ignition zone.

13. In a liquid fuel burning apparatus, in combination with a combustion chamber having a hearth and an upright wall with the hearth closing the bottom of said chamber in the vicinity of the wall, fuel distributing means for projecting a stream of liquid fuel above the hearth and toward said wall, means for projecting an air blast over the hearth toward said Wall, and an upright thin sheet metal member disposed in the general path of fuel and air projection and spaced materially from said combustion chamber wall in the direction of the projecting means.

ld. In the combination defined in claim 13,J

said fuel and air projecting means being designedv 4to substantially prevent admixture or carburetion prior to impingement upon said metal wall, and there being a substantially upright wall, of lesser height than said metal wall, disposed between the latter and the projecting means to deflect the air blast into intersection with the fuel stream adjacent the top of said metal wall.

15. In a liquid fuel burning apparatus of the wall flame type, comprising a hearth and associated means forming a combustion chamber surrounding a centrally located fuel projector: a substantially continuous carbureting structure spaced inwardly from the wall of the combustion chamber and provided with an upright fuel impact wall; and metal supporting and positioning means for said structure, said metal means comprising portions secured to the structure and integral offset portions secured to the hearth.

16. In a liquid fuel burning apparatus, in combination with a combustion chamber having a hearth and an upright wall with the hearth closing the'bottom of said chamber in the vicinity of the wall, fuel distributing means for projecting a stream of liquid fuel above the hearth and toward said wall; means for projecting an air blast toward said wall; and a refractory im- .pngement device of good heat conductivity disposed in the general path of fuel and air projection and spaced materially from `said chamber wall in the direction of 'said fuel projecting means to form a relatively large vertical space- .to thus form therebetween a horizontal space in communication with said -vertical space.

17. In a liquid fuel burner of the'wall flame type, a Acombustion chamber having a hearth closing the bottom of the chamber and a wall aosaeoz extending around the periphery of said hearth, means "for projecting liquid fuel toward the hearth periphery, a heat resistant sheet metal combustion ring of substantially uniform height spaced inwardly from said wall and in the path of the projected fuel, and means for supplying air for admixture with the fuel adjacent the top of said ring.

18. I n a liquid fuel burner of the wall flame type, a .combustion chamber having a hearth and a wall extending aroundvthe periphery of said hearth, means for spraying oil towardv the hearth periphery, a relatively thin combustion ring of material of high heat conductivity spaced inwardly from said wall'and presenting a vaporizing face in the path of the sprayed fuel, and

means for passing a current of air toward the top of the ring tc produce a mixtureof fuel and air for combustion in an annular zone extending from a locus above the -top of the ring downwardly between said combustion ring and the peripheral wall, whereby the temperature of the vaporizing face will rapidly vary in accordance with any changes of temperature in the combustion Zone.

LHLTON A.

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