US2039936A - Oil combustion apparatus - Google Patents

Description

y 1936- o. c. SCHROEDER ET AL 2,@39,936

OIL COMBUSTION APPARATUS 3 Sheets-Sheet 1 Filed Jan. so, 1935 .[fiven 07.19.- Oscar C. osckroeder,

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y 1936- o. c. SCHROEDER ET AL 6 OIL COMBUSTI ON APPARATUS Filed Jan. 50, 1955 3 Sheets-Sheet 5 Patented May 5, 1936 UNITED STAT PATENT OFFICE OIL COMBUSTION APPARATUS Illinois Application January- 30, 1933, Serial No. 654,356

20 Claims.

Our primary object is to provide an oil-combustion apparatus of the type in which the combustion of the oil delivered from the center of the hearth takes place generally in the form of a ring at the outer peripheral por ion of the hearth, improvements to the end that complete combustion of the fuel will be elfected and maximum .efficiency obtained.

More specific objects are to provide a hearth of such construction and associate therewith .3 burner in such a way, that the result above re.- ferred to may be effected; to provide, in a-structure of the character above referred to and embodying gas-ignition means, for the shielding of the gas flame from the direct blast produced by the burner, without impairing its usefulness for igniting the fuel; to provide for the thorough intermixing of the oil, in vaporized condition, and the air to effect complete combustion relatively close to the hearth; to provide a construction whereby leakage of air through the hearth will be prevented; and other objects as will be clear from the following description.

Referring to the accompanying drawings:

Figure 1 is a view in elevation of a furnace embodying our inventionyand comprising, as an element thereof, an oil-burner assembly certain parts of the structure shown being represented in sectional elevation.

Figure 2 is an enlarged broken sectional view in elevation of the ignition means for the burner and a portion of the furnace hearth, the section being taken at the line 22 on Fig. 3, and viewed in the direction of the arrow.

Figure 3 is a broken plan view of the portion of the hearth shown in Fig. 12 showing the pilots in plan section.

Figure 4 is a developed view in elevation of the portion of the hearth shown in Fig. ,3, the hearth being viewed from the interior ofthe furnace and the view being taken along the line';4-,4 on Fig.

3 and viewed in the direction of the-arrows.

Fig. 5 is a plan View of my improved hearth ring sections of such shape, ,number ,and grouping as to form a hearth ring of one diameter; and

Fig. 6, a similar view of the hearth ring sections of such number andigrouping as to form a ring of a larger diameter.

Referring to the particular construction shown, 9;,represents-a furnace, shown as of the hot-water boiler type, having a combustion chamber I formed with a hearth portion of refractory ma terial centrally apertured and supported on a centrally apertured plate II, as forrexample' of metal, carried by the base I2 of thefurnac'ei The hearth portion shown formed of any suitable refractory material comprises a ring-like base portion I3 having at its outer periphery an upwardly extending ring-like side-wall forming flange III, a ring I superposed on the ring portion I3 concentrically therewith but of smaller diameter, and a ring I6 preferably formed of arcu ate sections disposed ina circular series and resting on the outer marginal portion of the ring I3 beyond the ring I5 and filling the space between the. ring I5 and the lower end portion of the sidewallforming flange M.

It may here be said that in the assembling of the parts of the combustion apparatus the oil burner assembly is positioned at the lower end 1;

of the combustion chamber I0, and the plate II then applied in the position shown. The base portion I3 preferably formed of cement is then ,cast on the plate, and, if desired, the flange portion I4 cast separately, in which case the one portion last to be cast is cast before the other sets. Thus in eithercase the base with its flange forma monolithic structure free of joints. After applying to place the sections of the hearth ring I6 cement to form the ring I5 is cast on the base portion I3.

The ring It comprises an annular base portion H the inner periphery of-which is of stepped form to provide, at a considerable distance below ts upper edge I8, an annular oil-receiving trough,.orgroove, I9 and a lower inwardly located annular recess 2|] presenting anannular shoulder-forming'wall ZI, The hearth-ring I6 also comprises concentric annular inner and outer series of breaker teeth 22 and 23, respectively, which rise from the base of the member I6 and are disposed outwardly beyond the groove I9. These two series of teethare shown as spaced apart ina direction radially of the burner-structure, and-the outer series of teeth 23 is set in from thecircumference of the base member I6 and thus from the side-wall-forming flange I 4. The teeth .22 forming the inner series thereof are shown as ,of greater height than the teeth 23, which is preferred in the case of the larger sizes of combustion apparatus; and the same number of teeth are provided in each series thereof and they arefiodisposed, as shown, as to be in radial alin'ement'witli each other.

"The upper face of the base portion II contains a series=of downwardly tapering radial slots 24 alternating with the teeth 22 and 23 and the ends of whichtermin-ate at upwardly and outwardly inclined walls 24 which merge with the upper surface I8 of the-baseportion I1.

The ring member I6 is recessed at its outer periphery as indicated at 26 and contains, in its upper face, an upwardly opening groove 21 extending tangentially of the ring member |6 from the recess 26 to, and through, the inner periphery of this ring member, this groove, which cuts through certain of the teeth 22 and 23, serving as a channel through which an igniter flame is projected into the space bounded by ring |6 to ignite the fuel as hereinafter described.

The structure also comprises an oil-burner assembly at the central opening in the hearth for projecting radially outwardly and against the inner surface of the ring member l6, atomized oil for the combustion thereof, adjacent the side wall of the combustion chamber as hereinafter described, the flame produced being in the form of a ring.

The oil-burner assembly comprises a neck-ring 28 located in the central hearth-opening and having an annular external flange 29 underlying the hearth, the ring 28 preferably having an extension ring-section 38.

' The neck-ring 28 is supported at intervals by pipes 32, as for example four in number, the lower ends of the pipes 32 extending into openings in a base-plate 33. Extending upwardly into the pipes 32 are rods 34 supported on the floor and slidable in the pipes 32, these several parts being held in vertically adjusted position by set-screws 35 on the plate 33 which extend through openings in the pipes 32 and bear at their inner ends against the rods 34.

The construction shown also comprises a vertically disposed electric motor 36 supported on a hollow member 31 arranged concentric with the opening in the neck ring 28, the member 31 being supported on the neck ring 28.

The upper end of the member 31 is formed of a hollow generally frusto-conically shaped portion 43 the open upper extremity of which, is surrounded by a ring 44 located concentrically within the neck ring 28 in spaced relation to both the portion 43 and neck ring 28.

Supported to extend downwardly into the upper end of the opening in the neck ring 28 but in spaced relation thereto throughout its circumference as shown, isa ring 46 the upper surface of which is so shaped as to present the annular upwardly tapering surface represented at 41.

Thearmature shaft of the motor 36 is represented at 48 and extends centrally upwardly through the portion 43 of member 31 to an elevation above the neck ring 28.

Secured to the upper end of the shaft 48 are air-forcing and air-distributing means of any desirable construction shown as comprising an inverted shallow, rotatable pan-like member 51 secured to the shaft 48, the rim 58 of the member 51 extending downwardly into the opening in the ring 46. The member 51 contains a series of openings 59 certain of which register with pipes 50 through which the oil, in the operation of the motor 36, discharges, the pipes 58 being shown as projecting outwardly a slight distance through these openings, these means also com prising air-forcing means (not shown) for discharging air outwardly through the openings 58. In the operation of the burner structure oil supplied to the air-forcing and air-distributing means discharges through the tubes 50 and air flows upwardly through the member 43 and thence discharges outwardly as a blast through the openings 59 in the pan member 51, the oil and air so discharging impinging against the hearth ring l6.

The burner assembly is mounted in the furnace at such an elevation that the oil discharging from the pipes 50 impinges against the hearth ring I6 substantially in the plane of the base portions of the inner row of teeth 22, viz., in the plane of the upwardly flaring walls of the slots 24.

The installation shown also comprises means for supplying an igniter flame to the hearth through the groove 21, these means which are of the flare-jet type comprising a pilot burner H producing a constant flame and a flare-jet burner 12 both shown as formed of vertically disposed pipes closed at their upper ends and located in the recess 26. The flare-jet burner 12 is located at the outer end of the groove 21 and contains an outlet 13 so disposed as shown that the flame,

produced by ignition of the gas discharging therefrom, travels through the groove 21 from its outer end, into and through, its inner end to the slgace within the hearth adjacent the oil trough The pilot burner 1| is located to one side of the groove 21 between the flare-jet burner 12 and the inner end of the groove 21 and contains a gas-outlet 14 so disposed, as shown, that the flame produced by the gas issuing therefrom extends into the groove 21 crosswise thereof, intersecting the stream of gas issuing from the flare jet burner 12 when the latter is opened to the gas supply as hereinafter described, and impinging against the opposite side wall of the groove 21.

The means shown for controlling the supplying of gas to the burners 1| and 12 may be of any desirable construction such as is commonly in use and preferably of the type operating automatically in the starting of the main burner to supply gas to the flare jet burner only during, and for a few seconds after, the main-burner-starting operation; the means shown comprising a magnetic gas control assembly formed of a casing 15 surmounted by a head 18 containing a passage 11 into which the pipe 18 for supplying gas to the burners 1| and 12 opens, the passage 11 communicating, under the control of a needle valve 19, with a passage connected by a pipe 8| with the pilot-burner pipe 1|. The passage 11, which is reduced at its lower end, contains an opening 82 at which it communicates with a pipe 83 leading to the flare-jet-burner pipe 12. Interposed between the inlet pipe 18 and the outlet opening 82 is a valve 84 shown as in the form of a ball on the upper end of a stem 85 pivotally connected at its lower end to the vertically movable core 86 of a solenoid 81 in the casing 15, the coil of which is represented at 88. In accordance with common practice the coil 88 is assembled with suitable electrically controlled devices (not shown), for energizing the coil to raise the core 86 and unseat the valve 84 and thus permit gas to flow to the flare-jet burner 12 during the burnerstarting periods to ignite the atomized fuel and air-mixture discharged to the rim of the hearth as above described.

In the starting of the burner the oil discharging to the hearth as hereinafter described is ignited by the gas-flame produced by the ignition means, the groove 21 being so positioned as shown that the igniter flame is projected into the combustion chamber ID in the direction of rotation of the oil and air delivering means described, viz.,

in the direction of the arrow in Fig. 3.

As a premise to a description of the particular manner in which the burner functions in connection with the hearth construction shown, it may be statedthat the oil discharging from the pipes 50 is substantially uniformly distributed in a circular substantially horizontalsheet around the main burner, impinging against the hearth ring in the plane of the base portions of the inner row of teeth 22 as above stated, these teeth as also the vertical rear side Wall of the oil groove I9 becoming very hot in the continued operation of the burner and thus thoroughly vaporizing the oil.

The air, however, in discharging from the burner through the openings 59 spreads vertically to a slight degree, portions of the blast forcibly impinging against the teeth 22 and passing through the spaces therebetween and other portions thereof sweeping downwardly along the upper surface of the hearth below the plane of the oil stream. The lower portion of the air stream strikes the wall 2| thereby causing the air to be deflected upwardly against the faces of the teeth 22, most of the air passing by, without entering, the oil groove I9 thereby causing a deficiency of oxygen in this groove so that the oil vapors therein are not combustible to a. great degree, which prevents maintenance of a steady flame in the oil groove. A large proportion of the air discharged through the openings 59 sweeps over the top of the teeth 22 into the zone above the teeth 22 and 23 and represented generally at 89.

A part of the air which passes between the teeth 2 2'- as stated enters zones represented generally at 90' and 9| and probably most of the oil vaporized in front of the teeth enters these zones and inasmuch as the amount of oil vapor which passes between the fingers into the zones 90 and 9| is far in'excess of the amount that can be consumed by the air which enters these zones with the oil vapor, only partial combustion of the oil vapor takes place in zones 98 and 9|. As will be understood the air and oil vapor passing through the radial spaces between the teeth expand with resultant decrease in velocity and swirl spirally in the spaces between the teeth 22 and 23 and also the spaces behind the teeth 23 which promotes thorough intermixture of the oil vapor and the air. The velocity of the oil vapor and air entering zones 90 and 9! decreases to such an extent that stable combustion can be established in these zones; however, the partially consumed gases in traveling from the zones of incomplete combustion adjacent the teeth 22 and 23 into zone 89 become mixed with the air flowing into this zone as above stated forming a completely combustible mixture which thereupon burns in this zone.

The feature of forming the hearth ring IS with the recess 20 affording the wall surface 2| is of advantage inasmuch as the height of such surface is predetermined and fixed in the manufacture of the hearth ring, and reliance is not required to be placed on the workman installing the apparatus in a furnace, to produce the desired height of wall, as in the case of these structures wherein the elevation of the lower exposed edge of such 7 wall is determined by the height to which the 16 would be two inches from the outside curved surface I 6 of the section and 7 inches from the center about which inner and outer arcsurfaces of the section are described and the distance between the points Hi -Hi is 2 pi or 6.28 inches less the necessary clearance for cement joints between adjacent sections, when it is desired to cement the joints between adjacent sections. The inclination of the surfaces I6 is such that in a hearth of I8 diameter adjacent tile will fit together at the surfaces lfi'" as shown in Fig. 5, and by using an additional one of the sections to form a hearth of 20 diameter adjacent tile will fit together at the surfaces l6 as shown in Fig. 6. This same feature of providing the hearth sections with double inclined ends as above described also applies to smaller and larger hearth sizes than those above referred to, as for example hearths 14" to 16 or 22 to 26 in diameter, in which cases the radius differs accordingly so that one size of hearth section will serve for hearths of 14" to 16" diameter and another size for hearths of 22" to 26" diameter.

While we have illustrated and described a particular construction embodying our invention we do not wish to be understood as int-ending to limit it thereto as the same may be variously modified and altered without departing from the spirit of the invention.

What we claim as new, and desire to secure by Letters Patent, is:

1. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of said hearth and extending above the latter for projecting finely divided oil and air against the raised portion of said hearth, said raised portion comprising an annular series of breaker teeth spaced from the surrounding wall structure to: provide-a combustion space outwardly beyond said teeth with which the spaces between the teeth communicate the side walls of the spaces between the teeth at the bottom portions thereof converging downwardly to produce substantially V-shaped spaces and said means being so positioned as to discharge the oil against the bases of said teeth and into said substantially V-shaped spaces.

2. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said wall structure and with which the spaces between the teeth of said outer row communicate, the teeth of said rows being in substantial radial alinement.

3. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raisedportion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said Wall structure and with which the spaces between the teeth of said outer row communicate.

4. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said wall structure and with which the spaces between the teeth of said outer row communicate, the teeth of the inner row extending above the teeth of the outer row.

5. A hearth ring comprising sections of arcuate form, those portions of the end surfaces of the sections adjacent the outer side of the hearth ring being on radii of the circle including the outer edge of the section and the portions adjacent the inner side being chamfered to extend at an angle to said portions of the end surfaces which are adjacent the outer side of the hearth ring.

6. In combustion apparatus, the combination of a furnace structure, a burner assembly located at the bottom of said structure substantially centrally thereof and a hearth for the bottom of said furnace structure comprising a base member having a central opening in which the burner assembly is positioned, said base member having an endless upwardly extending flange adjacent its outer periphery, the inner surface of said flange being circular and substantially concentric with the opening in said base member, said base member with its flange filling the space between said burner assembly and the side wall of the furnace structure and conforming to the latter, a hearth ring formed of separate end to end disposed sections placed in superposed position on said base member and against the inner side of said flange, and a ring on said base member completely spanning the space between said hearth ring and said burner assembly.

7. In combustion apparatus, the combination of a furnace structure comprising an upwardly extending wall, a hearth therein having a raised portion adjacent its periphery, means at the center of said hearth and extending above the latter for projecting air and finely divided oil laterally, said raised portion having an angularly disposed channel opening through the inner face of said raised portion, and ignition means the flame from which extends forwardly along said channel, said last-named means being located between said raised portion and the wall of said furnace structure and subjected to the heat of burning gases in the furnace outwardly beyond the inner face of said raised portion.

8. In combustion apparatus, the combination of a furnace structure comprising an upwardly extending wall, a hearth therein having a raised portion adjacent its periphery, the upper portion of the outer face of said raised portion being spaced from the wall of said furnace structure, means at the center of said hearth and extending above the latter for projecting air and finely divided oil laterally, said raised portion having an angularly disposed channel opening through a side of said raised portion facing said means,

and ignition means the flame from which extends inwardly along said channel, said lastnamed means being located between the upper portion of the outer face of said raised portion andthe wall of said furnace structure.

9. In oil combustion apparatus, the combination of a combustion chamber having a hearth and presenting an impact wall, rotary means at the center of said hearth and extending above said hearth for projecting air and finely divided oil laterally against said impact wall, the raised portion of said hearth having an angularly disposed channel opening into the combustion chamber through said impact wall, and ignition means the flame from which extends inwardly along said channel, said channel being so disposed that the ignition flame discharges into said combustion chamber generally in thedirection of rotation of said first-named means.

10. In oil combustion apparatus, the combina-- tion of a combustion chamber having a hearth with a raised portion adjacent its periphery presenting upwardly extending teeth spaced apart around the combustion chamber, means at the center of said hearth and extending above the latter for projecting air and finely divided oil laterally, the raised portion of said hearth having an angularly disposed channel intersecting certain of said teeth and opening into the combustion chamber, and ignition means the flame from which extends inwardly along said channel, the radial spaces between the teeth intersected by said channel being substantially of the same width as the spaces between the'remainder of said teeth to insure uniformity of performance around the hearth.

11. In oil combustion apparatus, the combination of a combustion chamber having a hearth and a surrounding wall structure, said hearth having a raised portion adjacent its periphery and comprising a base portion and inner and outer rows of teeth rising therefrom, the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said wall structure and with which the spaces between the teeth of said outer row communicate, the spaces between the teeth of each row thereof extending below the upper surface of said base portion and said upper surface containing radial grooves alining, and communicating, with said spaces, and means ,at the center of said hearth and extending above the latter for projecting air and finely divided oil laterally against said raised portion.

12. In combustion apparatus, the combination of a furnace structure, a burner assembly located at the bottom of said structure substantially centrally thereof and a. hearth for the bottom of said furnace structure comprising a base member having a central opening in which the burner assembly is positioned, said base member having an endless upwardly extending flange adjacent its outer periphery, in sealed relationship thereto, and a hearth ring on said base member within the confines of said flange, said hearth ring, at

assembly is positioned, said base member having an endless upwardly extending flange adjacent its outer periphery, the inner surface of said flange being circular and substantially concentric with the opening in said base member, said base member with its flange filling the space between said burner assembly and the side wall of the furnace structure and conforming to the latter, and a hearth ring placed in superposed position on said base member and against the inner side of said flange, the upper portion of said hearth ring being spaced from said fiange and forming, with said flange, walls of a combustion space, said flange extending above the top of said hearth ring.

14. A hearth element formed of a base portion and inner and outer rows of teeth rising therefrom, the rows of teeth being spaced apart with the spaces between the teeth of each row opening to the inner and outer faces of the teeth and the outer side of said base portion extending outwardly beyond the outer faces of the outer row of teeth.

15. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart, and the teeth of the inner row thereof extending above the teeth of the outer row.

16. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising a base portion and inner and outer rows of breaker teeth rising from said base portion, the teeth of said rows being in substantial radial alinement, the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said wall structure and with which the spaces between the teeth of said outer row communicate, and the upper surface of said base member having substantially radial grooves open at their inner ends and extending from the inner faces of the teeth of the inner row beyond the corresponding faces of the teeth of the outer row and located at the bottoms of the spaces between adjacent teeth of both of said rows.

1'7. A hearth element formed of a base portion 7 and inner and outer rows of teeth rising therefrom, the rows of teeth being spaced apart with the spaces between the teeth of each row opening to the inner and outer faces of the teeth and the outer side of said base portion extending outwardly beyond the outer faces of the outer row of teeth, said element having a portion presenting a substantially vertical inwardly facing curved wall surface located between the innermost surface of said base portion and the inner surfaces of the inner row of teeth and extending to an elevation below the upper ends of said last referred to teeth.

18. In oil combustion apparatus, the combi nation of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding Wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said Wall structure and with which the spaces between the teeth of said outer row communicate, the teeth of said rows being in substantial radial alinement and the side Walls of the spaces between the teeth of the inner row at the bottoms thereof converging downwardly to produce substantially V-shaped spaces, said means being so positioned as to discharge the oil against the bases of said teeth and into said substantially V-shaped spaces.

19. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery and having a surrounding wall structure, and means at the center of the hearth and extending above the latter for projecting finely divided oil and air against said raised portion, said raised portion comprising inner and outer rows of breaker teeth the rows of teeth being spaced apart and the teeth of the outer row spaced from the surrounding wall structure to provide a combustion space between the outer row of teeth and said wall structure and with which the spaces between the teeth of said outer row communicate, the teeth of said rows being in substantial radial alinement, and the side walls of the spaces between the teeth of each of said rows at the bottoms thereof converging downwardly to produce substantially V- shaped spaces, said means being so positioned as to discharge the oil against the bases of said teeth and into said substantially V-shaped spaces.

20. In oil combustion apparatus, the combination of a combustion chamber having a hearth with a raised portion adjacent its periphery, means at the center of said hearth and extending above the latter for projecting finely divided oil and air laterally, the raised portion of said hearth having a tangentially disposed upwardly opening channel opening into the combustion chamber, said hearth having a recess at its outer periphery which recess opens into the outer end of said channel, and ignition means in said recess for directing an ignition flame inwardly along said channel, for the purpose set forth.

OSCAR C. SCHROEDER. STANLEY PERRY.

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