US2980171A - Gas and oil burner - Google Patents

Description

April 18, 1961 A. A. FURCZYK ETAL 2,980,171

GAS AND OIL BURNER Filed April 16, 1949 2 Sheets-Sheet 1 FIG.|

FIG.2

INVENTORS ALFONS A. FURCZYK JAMES B. HENWOOD FREDERICK S. BLOOM JAMES E. HOVIS ZKAJWJ hm ATTORNEY.

April 1961 A. A. FURCZYK EI'AL 2,980,171

GAS AND OIL BURNER Filed April 16, 1949 2 Sheets-Sheet 2 F l G. 4 ll7 F l G. 3

FIG. 6

FIG. 5

TNVENTORS ALFONS A. FURCZYK JAMES B. HENWOOD FREDERICK S. BLOOM BY.JAMES E. HOVIS ATTORNEY.

Unite States PatentO GAS AND OIL BURNER Alfons A. Furczylr, Wyncote, James B. Henwood, Bala- Cynwyd, and Frederick S. Bloom, Mount Lebanon Township, Pa., and James E. Hovis, Cleveland, Ohio, assignors to Selas Corporation of America, Philadelphia, Pa, a corporation of Pennsylvania Filed Apr. 16, 1949, Ser. No. 88,022

15 Claims. 01. 1ss 11 'The present invention relates to burners, and more particularly to a radiant type burner that is adapted to use either oil or gas as a fuel. V

'In the pastit has been the custom to provide separate burners for oil and gas when both fuels were to be used in a furnace. In some cases the two types of burners have been built into a single assembly. When thisis done, it

the block and into the base ofthe cup is a distributor member through which fuel, either gas or oil, and all of the air required for combustion are passed. The distributor is so shaped that complete mixing of the gas and air, or complete vaporization andthen mixing of the oil and air takes place prior to the time the mixture is discharged intothe cup where iti s burnt. Regardless of the fuel which is being used, the mixture is distributed to the cup in a plurality of small jets, and is burned completely in the cup to heat it to a high degree of incandescence. The cup then forms a source of radiant heat that is augmented by the high velocity productsof combustion produced as a result of the burning of the mixture.

It is an object of the present invention'to provide a burner that will operate with equal efiiciency and at substantially equal temperatures Whether it is'fired with gas or oil. 7

It is a further object of the invention to provide a burner using oil as a fuel in which the oil is completely vaporized and the vapor mixed with air in quantities for complete combustion to take place. It is a further important object of the invention to provide a burner using oil as a fuel in which the oil can be vaporized to burn as a true gas with the use of cold air. In the operation of previous burners it has not been possible to vaporize oil in a burner without the use of hot air or steam as a vaporizing agent. With the present invention, however, air at atmospheric temperature can be used. p

It is a further object of the invention to provide a burner of large capacity that can be used'in a small combustion space. The burner operates to supply a complete mixture of air and fuel in gaseous form to the combustion spacer This mixture is burned at high velocity in very short flames to produce an intense heat. The heat is transferred to an object to be heated in the form of radiant heat and in the form of convection heat by the hot products of combustion.

The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention,jhowever, its advantagesfland specific objects attained with its use, ref erence should be had to the accompanying'drawings and descriptive matter in which we have illustrated and described a preferred embodiment of the invention.

In the drawings:

Figure 1 is a sectional view of a complete burner;

Figure 2 is a view from the right of Figure 1;

Figure 3 is a view taken on line 3-3 of Figure 1;

Figure 4 is a section of a modified form of tip;

Figure 5 is a section of another modified form of tip;

Figure 6 is a view taken on line 6--6 of Figure 5; and

akFigure 7 is a section of still another form the tip can t e.

Referring to Figure 1 there is shown a portion of the furnace wall refractory 1 with a conventional sheet metal backing 2 into which the burner of the present invention is to be inserted. The burner includes a burner block 3 of suitable refractory material which is formed with a cup 4 having an opening in its base. Back of the cup is a tunnel block 5, also of refractory, and having an opening in it through which the distributor assembly 6 containing other burner parts is inserted. The assembly includes a first cylindrical member 7 which is welded to a second cylindrical member 8 in such a fashion that a shoulder 9 is formed between the two parts. The'second cylindrical member is attached to a casting 12 by means of an attaching ring ll that surrounds a shoulder 13 on the cylindrical member 8. The casting and the ring are held together as shown in the drawing by means of bolts 14. The entire assembly is fastened to the metal backing 2 of the furnace bya flange 15 which is formed on the ring, and through which bolts 16 are inserted into the furnace. [It is noted that the assembly is projected the proper distance into the cup 4 by engagement between the shoulder 9 and a corresponding shoulder that is formed in the tunnelblock 5. Suitable cement can be inserted between the cylindrical member 8 and the opening in thetunnel. block in order to insure an air-tight connection between'these two parts.

The first or inner cylindrical member 7 is formed with a plurality of parallel passages 17 which extend throughout its length and, around the circumference of the member as is best shown in Figure 3 of the drawing. There are also provided a corresponding number of shorter parallel passages 18 displaced radially inward from the passages 17. The space between the inner ends of passages 18 and the right end of the member form each pair of passages are separated by radially disposed partitions or petals 21 as shown in the drawing. A tip 22 extends across the top of the member so that each of the openings 17 and 18 is connected with the cup of the burner by a substantially radially extending channel. Normally the cylindrical member 7 and the passages formed therein are made in one piece as a casting. It is notedthat. the portion of. the member. extending into chamber 19 forms a small cone 23 that is centrally disposed with respect to the inner passages 18.

The casting 12 forms a chamber 24 that is connected with an air supply pipe 25. This casting is also formed with an annular space 26 that, in cooperation with a cap 27 held in position on the casting by bolts 28, forms an annular chamber through which gaseous fuel is supplied to the burner. This annular chamber is connected with a gas pipe 29 having avalve 30 in it; as is best shown in Figure 2 of the drawing. A tube 31 having a valve 32 in it permits chamber 26 to be connected with the air supply pipe 25. Extending from chamber 26 are a number of parallel tubes 33, one of which terminates inside the right end of each passage 17. The tubes are all of a' 27 into chamber 19 where it is centered by a flange or collar 35 formed on its left end. The flange is snugly received by the wall of the chamber, but is provided with a series of circumferentiallyspaced holes 36 through which air may flow. The atomizer assembly is'held in position by the threaded engagement between a fitting 37 on its right end and the cap 27. Any atomizer which is capable of breaking the oil into small droplets may be used. As shown in the drawing, however, there is a pressure type atomizer which has a tube 38 extending through the same for the oil. This tube is connected to a pipe 39, having a valve 40 in it, leading to a supply of oil. Around tl e tube 3% and within the assembly there is an air passage 41 which is connected with a pipe 42 to a source of air under pressure. In the operation of the atomizer oil is forced through pipe 38 to the exit opening 43 adjacent to the right end of chamber 19, where it is broken up into fine droplets by the air coming through passage Therefore an oil spray is forced into chamber 31?.

In the operation of the burner using gas as a fuel valve 32 is closed so that there is no communication between the air supply pipe and the annular gas chamber 26, and the oil valve 40 is closed. Air is introduced into chamber 24 at a pressure of approximately 36 W.C. and gas is introduced through pipe 29 at a pressure of substantially 54 W.C. The pressure of the gas will vary somewhat with its B.t.u. content. The higher the B.t.u. content the lower the gas pressure. Gas flows from chamber 26 through the tubes 33 and is mixed with air flowing in passages 17 around the outside of the tubes 33. The tubes and the passages are so proportioned in size that the amount of air introduced in these passages is insufficient to form a combustible mixture. The remaining air that is necessary to support combustion passes through the openings 36 in collar 35 of the atomizer assembly and through passages 18 where it is mixed. with the rich air-gas mixture from passages 17. Thus, there is discharged into the cup 4 a plurality of radially directed streams of combustible mixture which burn with a plurality of flames to heat the surface of the cup to incandescence.

The angle of the channels between petals 21 relative to the contour of the cup is such that the flames sweep along rather than impinge upon the cup surface. Therefore, the hottest portion of the flame engages the cup to heat it rapidly. Cup temperature is rapidly raised above the ignition temperature for the mixture so that ignition can and does occur at an infinite number of points rather than right at the surface of each jet of mixture. The result is that complete combustion occurs within the cup thus giving the burner a higher capacity than would theoretically appear possible. Radiant heat for the furnace is provided by the incandescent surface of the cup and convection heat by the hot products of combustion. It is noted that an explosive mixture is not formed until just prior to the time that the gas is introduced into the cup. Therefore, there is no possibility of an explosion or backfire taking place in the burner.

In operating the burner with oil as a fuel, valve 32 is opened so that air coming in through pipe 25 will go through tubes 33 as well as around those tubes, and the valve 30 is closed. The atomized oil is forced into chamber 19 and carried from that chamber through the passages 18 and the channels between petals 21 into the cup 4 by air flowing through openings 36. The velocity of the air is sufiicient to carry the atomized oil into the passages leading to the cup before any coalescing of this oil can take place. The proportions of the openings 36 and the oil supply through the atomizer are such that an explosive mixture will not be produced in chamber 19. An explosive mixture of the atomized oil and air does not occur until the mixture reaches the radially disposed channels extending into the cup.

During operation air is supplied through pipe 25 at 36" WC. and the atomizing air is supplied through pipe 42 at 30 lbs. per square inch pressure. Oil is supplied through pipe 39 at at least 30 lbs. per square inch. Since valve 32 is open air will be blown through pipes 33 so that there will be no chances of any oil particles being sucked back into these tubes due to the fact that oil is at a higher pressure than the air.

When the burner is first started up with oil as a fuel the mixture issuing from the distributor tip will burn with a number of flames that are blue with yellow tips. After operating for a few minutes, however, the cup surface and the tip 22 will come up to temperature. Thereafter the burner operates with all of the characteristics of a gas burner. While it is operating the small particles of oil sprayed into chamber 19 by the atomizer are carried rapidly from the chamber through passages 18 to the cup. There is a relatively short path for them to travel, and cone 23 insures an even distribution through all of the passages. As the droplets reach the radial channels between petals 21 they are completely vaporized and mix with the air coming through passages 17 to form a combustible mixture. The vaporization takes place as a result of the heat which is conducted back to the channels through the tip 22. While the presence thereof is uncertain there may be a small amount of surface combustion taking place in the channels near the tip side thereof. This combustion could also supply heat to help vaporize the oil droplets. In any event vaporization occurs whether it is due to surface combustion in the channels or straight conduction through the tip 22. It is known that the tip becomes hot enough to vaporize the oil. Thus vaporization of the oil takes place as a result of the construction of the burner, and the use of hot air or steam to accomplish this function is unnecessary.

When either gas or oil is being used as a fuel sufficient air must be supplied for the fuel being used to obtain complete combustion. The proper proportions may be obtained with the use of any commercial type of ratio controller. When gas is being used as a fuel its volume is varied to obtain changes in temperature and the combustion air volume is correspondingly varied by the ratio controller. When oil is used as a fuel the same pro cedure is used. The volume and pressure of the atomizing air is kept constant at all times, however, to insure continued atomization of the oil. The volume of air used for atomizing purposes is so small compared to that used for combustion purposes that it can be disregarded when adjusting the ratio controlling mechanism.

In actual tests of the burner air and manufactured gas of approximately 530 B.t.u. per cubic foot have been burned with about 1400 cf. of gas per hour thus producing around 750,000 B.t.u. for a burner. Equal B.t.u. values have been obtained with oil being burned at the rate of 5 /2 gallons per hour. During such operation the cup is heated to approximately 2860 F. and the tip 22 of the distributor is heated to around 1750 F. Burners have been operated on both oil and gas to produce temperatures in the cup as high as 3000 F.

One of the most important features of the burner of the present invention is the accurate manufacture of the first tubular member 7 through which the air and gas that are to be burned are forced. It is necessary that the passages 17 be smooth and parallel to each other and that the passages 13 be parallel to the passages 17. It is also necessary that the metal of which the member 7 is formed be a high temperature alloy or ceramic that is capable of retaining its shape indefinitely while the burner is being fired. There are shown in Figures 4 to 7 inclusive different embodiments of the cylindrical'mernber 7 showing different ways in which this member may be manufactured.

Due to the difliculty that is encountered in casting some types of high temperature alloys it is necessary at times to make the tip separate from the body of the cylindrical member. In Figure 4 there is shown a cy1indrical member 107 which has passages 117 and'118 formed in it. The central portion of the member inside of the passages 118 is threaded so that a tip 122 may be separately made and inserted into the cylindrical member. As shown herein the tip 122 is provided with a threaded stem vportion 123 whose end is substantially conical in shape. This tip is screwed tightly into the cylindrical member 107 so that the-inner surface of the tip engages the outer portions of petals 121 to form the channels through which the air and the fuel are passed.

In the embodiment of Figure 5 is a unit of three piece construction. The tip is formed in one piece, but it is shorter than that of the previously described embodiments in that the tip itself only extends as far as the inner ends of passages 218. This tip is cast as. a single piece with the passages 217 surrounding the passages 218 and with the petals 221 integral with the tip 222. There is also provided a central conically disposed stem portion 223. It is noted that this latter portion can be of the shape shown in Figures 4 and 5 or can be shorter as shown in Figure 1, if it is so desired. The tip itself is welded at 224 to a cylinder 225. Snugly received inside of the cylinder is a tubular member 226 that is formed around its circumference with a series of grooves 227. When the members 225 and 226 are assembled as shown in the drawing the channels 227 will form outer passages that coincide with and form continuations of the passages 217. By forming the tip of three portions as shown in this figure some of the difficulties of casting parallel elongated passages in some high temperature alloys can be overcome;

The embodiment of the invention disclosed in Figure 7 is similar to that of Figure 4 in that a casting 307 is provided with passages 317 and 318. This casting has threaded into an opening formed centrally thereof a small tip 322 which terminates in a stem portion 323 that is shown herein as ending in a point, rather than a rounded dome. In order to cover the petals 321' so that the radial channels are formed through which the gas and air is passed there is provided a ceramic cap 324 that is threaded to the exterior of cap 322. It is necessary that this tip be made of some ceramic which has a high heat transmission rate such as beryllium oxide. This is necessary in order that the heat may be transmitted through the cap in sufficient amounts to vaporize the supply of atomized oil as the latter is forced out of the tip through passages 318. At times it may be necessary to protect further the metal of the tip and to' this end there is shown a ceramic cylinder 325 surrounding the metallic cylinder 307. This cylinder will tend to help cool the metal parts of the distributors From the above description it will be seen that there is provided a compact, eflicient burner that will operate on either gas or oil as a fuel. To change from one fuel to another-it is only necessary to operate suitable valves that will be provided in the oil and gas lines leading to the burner. The construction of the burner is such that an explosive mixture of fuel and air is not made until just prior to the time the mixture is forced into the combustion space. This is of importance, particularly in large installations where many burners are used. Another important feature of the invention lies in the fact that the same air supply at atmospheric temperatures may be used whether oil ,or gas is being used as a fuel. The combustion space required for the burner, especially when it is using oil, is substantially smaller than has hitherto been thought possible.

While in accordance with the provisions of the statutes we have illustrated and described the best form of embodiment of our invention now known to us it will be apparent to those skilled in the art that changes and modifications may be made in the form of the apparatus without departing from the scope of the invention, as set forth in the appended claims, and that. in some cases 6 certain features of our invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a burner the combination of a member having a chamber formed therein, an atomizer for oil extending into said chamber, means including passages formed in said member through which atomized oil and primary combustion air can be moved from said chamber into a space to be heated and where the oil is burned, means including additional passages in said member through which secondary air can be forced into and mixed with said atomized oil and primary air just prior to the time it moves into said space, and means disposed axially in front of said chamber and passages to conduct heat to said mixture to vaporize at least some of said oil so that it will burn as a gas.

2. In a burner, the combination of a member formed with a chamber therein, said. member having a plurality of passages extending radially from said chamber to a surface of said member, oil atomizing means in, said chamber operative to direct oil atomized thereby toward said passages, means formed with openings around said atomizer with the openings extending toward said pas sages and through which air may be supplied to carry the atomized oil through said passages with a minimum of turbulence, said member being formed with additional passages through which air is forced to be mixed with the atomized oil just prior to the time it reaches the surface of said member, and means forming a part of said member to conduct heat to the atomized oil flowing in said first passages. Y

3. In a burner, a cylindrical member having one end adapted to extend into a space to be heated, said member being formed with a chamber and axially extending passages leading into and 'out of said chamber, the passages leadingout of said chamber terminating in radially extending portions leading to the surface of said member, additional passages formed in said member and terminating in said radially extending portion, means to supply atomized oil to said chamber, means to supply air through said first mentioned passages to carry the oil from said chamber to the space to be heated, means to supply additional air through said additional passages, the air and oil mixing in said radially extending portions to form a combustible mixture, the end of said member beyond said radially extending portions conducting heat to said portions to vaporize at least some of the oil in them.

4. In a burner, the combination of a refractory block having a cup formed in one face thereof and an opening extending from the base of said cup to an opposite face of said block, a'distributor member in said opening and having an end thereof projecting into said cup, said member being formed with a centrally disposed chamber, a pluratity of pairs of radially displaced passages spaced eircumferentially around said member, the inner passages of each pair terminating in said chamber, said member having a radial channel extending from the periphery thereof in said cup to each pair of passages, means to supply finely dispersed oil to said chamber from which it can flow through the inner passages and channels to said cup, means through which gas may be supplied to the outer passages so it can flow through the channels to said cup, and means to supply air through all of the passages, the air mixing in the respective passages with the oil and gas.

5. The combination of claim 4 in which the means to supply oil is an atomizer extending into said chamber, a flange on said atomizer received snugly by the walls ofsaid chamber, said flange being provided with a plurality of axially extending openings through which airmay pass around said atomizer'into said chamber.

6. The combination of claim 4 in which the means through which gas is supplied to said outer passages ineludes structure forming a second chamber, tubular means 7 extending from said second chamber to each of said outer passages and terminating in said outer passages, said tubular means being slightly smaller in diameter than said passages whereby air can flow around said tubular means into said passages.

7. The combination of claim 6 in which there is a connection between said means to supply air and said second chamber through which air can flow to said second chamber, and valve means in said connection.

8. In a burner used to heat a space, the combination of a distributor member having a portion thereof adapted to project into the space, said member being provided with a chamber therein and passages adapted to lead from said chamber to said space, said passages passing through said portion, means to supply oil in finely dispersed droplets to said chamber, means to supply air to said chamber to carry the oil droplets from said chamber through said passages to said space where it is burned, means including additional passages in said member communicating with said first-mentioned passages to supply additional air to form a combustible mixture with said oil droplets, said portion of said member adapted to project into said space conducting heat to said oil droplets to vaporize at least some of said oil droplets prior to the time they reach said space whereby the combustible mixture will burn with the characteristics of a gas.

9. in a burner for heating a space, the combination of a member having a portion adapted to project into the space and heated to a temperature at least equal to that required to vaporize oil, said member being formed with a chamber and substantially radial passages extending from said chamber to the surface of said member at the portion thereof extending into said space, said member also being formed with additional passages terminating in said first-mentioned passages adjacent to the surface of said member, means to supply finely divided oil droplets to said chamber, means to supply air through said chamber in sufiicient quantity to carry the oil droplets through said first-mentioned passages, and to supply air through said additional passages, said portion of said member adapted to project into said space conducting heat to said passages to vaporize at least some of the oil droplets.

10. In a burner, the combination of a refractory block having a cup-shaped depression formed in one face thereof with an opening extending from the base of the depression to an opposite face thereof, a distributor member for a combustible mixture extending through said opening into said cup, said member being formed with a chamber adjacent to the extending into said cup, and with substantially radially extending passages between the chamber and the cup substantially adjacent to the cup surface, an oil atomizer for oil opening into said chamber and directed toward said passages, said member being formed with a series of apertures in said chamber adjacent to said atomizer, and means through which air is passed through said apertures to carry oil atomized by said atomizer from said chamber through said passages into said cup to be burned.

11. In a burner, the combination of a refractory block having a substantially conical depression formed in one face thereof and an opening extending from the apex of the depression to an opposite face of the block, a distributor member having an end extending through said opening into said depression, said end being of heat conducting material and forming one Wall of a chamber in said member, means forming radial passages in said distributor extending from said chamber and opening into said depression substantially adjacent to the surface of the depression, means to supply finely dispersed liquid fuel to said chamber, means to supply air to said chamber to mix with the dispersed fuel, the mixture passing through said passages to be burned in said depression to heat the same and to heat said end of said distributor member, heat being conducted through said end to said chamber to preheat the mixture before it flows through said pas sages.

12. In a burner, the combination of a block of refractory material having a substantially conical depression in one face thereof and an opening extending from the apex of said depression to an opposite face of said block, a substantially cylindrical member received in said opening with an end thereof extending into said depression and below the face thereof, said member being formed near said end with a chamber, said member having a plurality of radially directed openings extending from the periphery thereof adjacent to the surface of said depression to said chamber, said openings being at an angle to the axis of said member substantially equal to the angle of the wall of said depression relative to the axis of said member, an oil atomizer extending into said chamber and directed toward said openings, means to supply oil to said atomizer, the atomized oil filling said chamber, and means through which air is supplied to said chamber to carry the atomized oil through said openings in a series of radially directed jets to be burned along the surface of said depression.

13. The combination of claim 12 in which said member is made of metal, the end of said member adapted to be heated and adapted to conduct heat to said chamber to vaporize at least some of the oil supplied to said chamber by said atomizer.

14. The combination of claim 12 including means surrounding said atomizer to hold said atomizer axially aligned in said chamber, said means being provided with openings spaced circumferentially around the atomizer.

15. In a burner, the combination of a refractory block having a substantially conical depression formed in one face thereof and an opening extending from the apex of said depression to the opposite face of said block, a hollow, cylindrical metal member with a closed end re ceived in said opening with the closed end'projecting into the bottom of said depression, said member being provided adjacent to the end thereof with a plurality of substantially radially directed openings extending from said depression near the surface thereof to the interior of said member, means centrally located in said member through which finely divided oil may be supplied to the interior of said member adjacent to the closed end thereof, and means forming a passage around saidzlast-named means through which gas is supplied to the interior of said member adjacent to the closed end thereof, the gas passing through said openings to be burned in said depression in a series of radially directed jets.

References Cited in the file of this patent- UNITED STATES PATENTS Breault Nov. 2, 1948

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