US1990962A - Gas burner - Google Patents

Description

M. THORSON Feb. 12, 1935.

GAS BURNER Filed July 21, 1935 2 Sheets-Sheet 1 Feb. 12, 1935;

Filed July 21; 1953 2 Sheets-Sheet 2 Patented Feb. 12, 1935 7 GAS BURNER Martin Thorson, St. Charles, Ill.

. Application July 21, 1933, Serial No. 681,431

7 Claims.

This invention relates to heating devices, and has to do with a gas burner particularly suitable for use in heating plants and the like.

One of the main objects of my invention is to provide a gas burner of simple construction and operation which can be applied with expedition and facility to heating plants of known type and which is highly economical in the use of gas. A further object is to provide a burner in which the parts thereof are effectively cooled by air which is employed to support and promote combustion. Another object is to provide means for thoroughly mixing the air with the gas and for heating this mixture preliminary to combustion thereof so as to promote complete combustion of the resulting mixture, this mixture employing a large volume of air in proportion to the volume of gas. Further objects and advantages of my invention will appear from the detail description.

In the drawings:-

Figure 1 is a fragmentary vertical sectional view through the lower portion of a heating plant embodying a burner in accordance with my invention, parts being shown in elevation;

Figure 2 is a section taken substantially on line 22 of Figure 1, on an enlarged scale;

Figure 3 is a section taken substantially on line 3-3 of Figure 1, on an enlarged scale;

Figurel is a section taken substantially on line 44 of Figure 3; c

Figure 5 is a section taken substantially on line 5-'-5 of Figure 3;

- Figure 6 is a section taken substantially on line 6-6 of Figure 2, on an enlarged scale;

Figure 7 is a section taken substantially on line 77 of Figure 6;

Figure 8 is a section taken substantially on line -8-8 of Figure 7;

Figure 9 is a transverse vertical sectional view through a modified form of burner embodying my invention, and associated parts. I

This application is a continuation in part of my application for Gas burner, filed January 23, 1933, Serial No. 652,995.

In Figure 1 I have illustrated a burner embodying my invention as applied to a furnace of a domestic hot air heating system of known type, by way of example. The furnace is of known construction and comprises a casing 1 within which is a fire-box provided with a refractory lining 2. Furnaces of this type are commonly provided with 'a grate structure comprising an outer ring section 3 and a central circular section which, in applying my burner, is removed. An ash pit 4 is provided beneath the grate and, when my burner is installed; the ash pit door is removed and is replaced by a suitable plate 5 secured in position in any suitable or preferred manner.

Preferably,

a layer of refractory 6 is placed upon the grate ring 3 and serves to shield the parts within the 5 ash pit from the heat within the fire-box.

The burner 7, which is of circular shape in plan, is suitably supported within the ash pit 4, as by means of an angle iron ring 8 within which the burner seats, this ring being supported by suitably disposed legs 9. A plurality of tubes 10 extend from the burner 7 and are inclined upward and inward thereof at an angle of approximately 45 degrees. these tubes and are provided with suitable open- Tips 11 are secured in the upper ends of ings through which the air and gas mixture is discharged, this mixture being suitably ignited so that combustion thereof occurs as the mixture leaves the openings of the tips. of suitable refractory material extends upwardly An air dome 12 upper portion of the dome and flow over openings 12a provided in the upper portion of the dome. Thedome is thus heated at its upper portion, to a high temperature, the heated air flowing through the openings 12a into the fire-box for supporting and promoting combustion of the mixture discharged through the tips 11. In addition, the flow of the flames and the hot products of combustion across the openings 12a serves to draw air through these openings, thus inducing air into the dome 12 and through the conduit 14 and base 13, this action supplementing the natural flow of air due to heating of the upper portion of the dome and assuring adequate supply of air through the openings 12a. r

The burner comprises an outer air manifold 15 of circular shape in plan and of circular crosssection, and an inner gas manifold 17 shaped similarly to manifold 15 and disposed in concentric relation thereto.

Manifold 15 is provided 'grees.

Manifold 17 is provided with bosses 19 der suitable pressure. 1

disposed in aligned and concentric relation to the respective bosses 18. Air tubes 10 are screwed into the bosses 18, and gas tubes 20 are screwed into the bosses 19 and extend upwardly within tubes 10 in concentric, spaced relation thereto. Each of the gas tubes 20 is provided, at its upper end, with an outwardly projecting shoulder 21 which fits snugly within tube 10. This shoulder is provided with a plurality of air passages 22 extending therethrough and inclined across the axis of the tube 20 at an angle of approximately degrees thereto, the passages 22 being all similarly directed. An orifice plug 23 is screwed into the outer end of gas tube 20, this plug being provided with a restricted orifice 24 through which duit 15, this pipe extending through plate 5 and receiving air under-pressure from a blower 26 of known type which may be driven in any suitable. manner, conveniently by an electric motor.

" A gas pipe 27 is disposed withinpipe 25 in concentric'spaced relation thereto and is connected to gas manifold 17 for supplying gas thereto un- The flow of air and gas to manifold 15 and manifold 17, respectively, is

"controlled by a valve 28 disposedin pipe 25. This valve is shown in detail in Figures 3 to 5, inclusive, and comprises a suitable casing 29 within which a plug valve 30 is mounted for rotation, this valve being provided at one end with a flange 31 which contacts the adjacent end of the and has its inner end disposed adjacent the casing, there being a retaining ring 32 suitably secured on the other end ofthe valve and contacting the other end of the casing. Valve casing 29 is provided with pairs of air ports 33 open-' ing into air pipe 25, and with a gas port 34 disposed between ports 33 at one side of the valve casing, port 34 being suitably bored and threaded for reception of the outer end of gas pipe 2'7 which screws into this port. The valve casing 29 is further provided with a flanged nipple 35 extending therefrom and disposed midway between the air ports 33. Nipple 35 isconnected by a pipe 36 and T 37 to a gas main-38. A- tube 39 extends from the T 37 into the fire-box of the furnace upper endsof the burner tips 11, this tube providing a pilot light for igniting the combustible mixture discharged from the burner. A suitable valve40 is interposed in tube 39 for regulating 7 flow of gas therethrough. Valve 30 is provided ..with two air passages 41 extending diametrically thereof, and is further provided, between the passages 41, with an arcuate gas passage 42. When the valve plug 30 is turned into its full open position, the ends of the air passages 41 are in regprovided with metering openings 44 therethrough for determining the maximum flow of air through the valve. The parts are so related that the volume of air has the proper proportion to the volume of 'gas to assure maximum efliciency ofthe burner from the standpoint of combustion, it

being desirable to employ the maximum volume of air consistent with proper combustion of r the me- .8!??- e ep re en the sa ve-1 he- 9? .gas and the air and prgper; pre-h -.-Pr ie 1a t isqh reep th smixiurathr ueh of air and of gas may be regulated as desired,

while maintaining the proper proportion there-,

the air'manifold 15, through pipe 25 and gas is 7 supplied under relatively low pressure to gas manifold 17 through the gas supply pipe 27. The

gas issues through orifice 24 into the space above shoulder 21, and the air enters this space through theinclined passages 22, these passages serving 7 to impart rotation to the entering air. The space betweenthe upper face of shoulder 21 and the upper end, of tip 11 constitutes a mixing space,

and the gas and the air are subjected to high rotary turbulence within thisspace, which. assures thorough inter-mixing of the gas with the air. This mixture is then discharged through thetip openings 11a, and is ignited in the manner previously stated. After the burnenhas been -in ,op-:-1

eration .for a short time, the flap er portion of the dome 12 becomes 'highly heated; and contributes to efficient combustion, since theburning mixture is ejected against the upper portion of this dome, as above described. The heated;

air flowing through the openings 12w contributes further to combustion, with the result that complete combustion of thefuel is assured-anda large amount of heatis generatedbya comparatively small amount of gas eonsumed. lt will beg noted from Figure 1 that the upper portions of the tubes 10 and tips 11, in which' the mixing space is located, are disposed adjacent the;dome 12 so as to be exposed .to'the radiantheat of the dome and the radiant heat of the refractory lining for the fire box and the grate ring. This is advantageous, in that the air and gasmixture is heated preliminary to issuance thereof through the openings 1141, this preliminary heating concold. It will also be noted that the air flows around the gas supply tube 27 andthe gas manifold 17, as well as around the gas tube-20,. and is effective for cooling the same. ;'I 'his;is .advantageous as avoiding objectionable heating of any parts of the burner and associated elements disposed below the grate ring of the furnace.

I find thatthe proportions between'the various conduitsand passages of the burner,al fect.

the efiiciency of operation thereof. For ,most

efiicient operation, assuming-that the air mani fold has an interior diameter of two inches, the gas manifold should havean interior cl iameter o l in h the nt r o diamet ttube 10 should be three-eighthsof an inch,;the interior dia meter of thegas tube20should be threesixteenths of an inch, and the interior diameter of tip 11 should be three-eighths ofaninch. The

have a diameter of one .-sixty fgurth of an; inch. It is also desirable that the length ofthe mixing space abovethe shoulder 21,- and extendingto'the upper end of the tip 11, be approximatelyonethird of the total length ofthe-tip l1-,a nd tube 10. This assures thorough intermixing of the ea n ere tributing to combustion andavoiding thermahf losses such as would occur if the mixture-were.

the tip openings 1111, as above set forth. Though the proportions between the various passages and openings may be varied somewhat,I'find that the proportions above stated give the most satisfactory results from the standpoint ofefficiency and economy in operation.

In Figure 9 of the drawings I have illustrated a modified form of burner suitable for use in connection with hot water or steam heating systems. This burner is similar in construction and operation to the burner illustrated in Figures 1 to 8, inclusive, with the exception that air tubes 10a and tips 11 are inclined upward and outward at an angle of approximately 45 degrees, instead of being inclined upward and inward, so that the flame is directed outward and toward the surrounding water wall of the fire-box of a furnace in which the burner is disposed. Otherwise, the construction and operation of the burner is the same as that above described, and need not be set forth in detail.

What I claim is:-

1. In a gas burner, an outer manifold, an inner manifold within said outer manifold, means for supplying air under pressure to said outer manifold, means for supplying gas under pressure to said inner manifold, a series of burner assemblies extending upward from said manifolds, each of said assemblies comprising an outer air tube secured to and communicating with said outer manifold, an inner gas tube within and spaced from the air tube and secured to and communicating with said inner manifold, an annular member interposed between said tubes adjacent the upper end of said inner gas tube and provided with passages inclined with respect to the axis of said gas tube, and a relatively long cylindrical tube extending beyond said annular member and defining a relatively long mixing chamber extending beyond said passages, said passages discharging air from said outer air tube into said mixing chamber with a whirling motion, said inner gas tube discharging gas into said mixing chamber within the whirling volume of air, said cylindrical tube being provided at its outer end with a restricted orifice.

2. In a gas burner, an outer air tube, an inner gas tube within and spaced from the air tube, an annular member disposed between said tubes adjacent the upper end of said inner gas tube and provided with passages inclined with respect to the axis of said gas tube, a relatively long cylindrical tube extending from the upper end of said air tube and defining a relatively long mixing chamber extending beyond said passages, said passages discharging air from said air tube into said mixing chamber with a whirling motion, said inner gas tube discharging gas into said mixing chamber within the whirling volume of air, said cylindrical tube being provided at its upper end with a restricted orifice, and means for supplying air and gas to the respective tubes.

3. In a gas burner, an outer air tube, a gas tube extending upwardly within the air tube in spaced relation thereto and provided at its upper end with a restricted gas outlet orifice, said gas tube having an outer shoulder adjacent its upper end fitting snugly within the air tube and provided with passages inclined with respect to the axis of said gas tube, a relatively long tubular tip member extending from the upper end of the air tube and provided at its upper end with a restricted fuel mixture outlet orifice, said tip member being of substantially uniform interior diameter and defining a relatively long mixing chamber extending u warmy beyond saidshoulder and the gas outlet orifice-v ofs'aid gastube, the interior diameter of said mixing chamber 7 being materially greater than the diameter of thegas tube, and means for supplying aira'nd; "gas under pressure to the respective tubes.

4. In a gas burner, an outer air tube, a gas tube extending upwardly within the air tube in spaced relation thereto and provided at its upper end with a restricted gas outlet orifice, said gas tube having an outer shoulder adjacent its upper end fitting snugly within the air tube and provided with passages inclined with respect to the axis of said gas tube, a relatively long tubular tip member extending from the upper end of the air tube and provided at its upper end with a restricted fuel mixture outlet orifice, said tip member being of substantially uniform interior diameter and defining a relatively long mixing chamber extending upwardly beyond said shoulder and the gas outlet-orifice of said gas tube, the interior diameter of said mixing chamber being materially greater than the diameter of the gas tube, said tip member being exposed for the major portion of its length to the heat incident to combustion of the fuel mixture issuing from the upper end of the tip member, and means for supplying air and gas under pressure to the respective tubes.

5. In a gas burner, an outer cylindrical air tube, a cylindrical gas tube extending upwardly within the air tube in concentric spaced relation thereto and provided at its upper end with a coaxial restricted gas outlet orifice unobstructed for discharge therethrough of gas in a solid stream, said gas tube having an outer shoulder adjacent its upper end provided with passages inclined with respect to the axis of the gas tube, a relatively long tubular cylindrical tip member extending from the upper end of the air tube concentrically therewith and provided at its upper end with a restricted fuel mixture outlet orifice, said tip member being of a substantially uniform interior diameter materially greater than the diameter of the gas tube and defining a relatively long mixing chamberextending upwardly beyond said shoulder and the gas outlet orifice of said gas tube, and means for supplying air and gas under pressure to the respective tubes.

6. In a gas burner, an air manifold, a gas manifold within the air manifold in concentric spaced relation thereto, burner tube assemblies extending from the manifolds at an inclination upward and inward and each comprising an air tube communicating at its lower end with the air manifold and a gas tube within the air tube and communicating at its lower end with the gas manifold, tip members extending from the upper ends of the air tubes and defining mixing chambers extending a considerable distance above the upper ends of the gas tubes, and a hollow refractory member disposed between said tip members and extending thereabove, said assemblies being disposed to direct the burning air and gas mixture against the upper portion of said refractory member, the refractory members being open at its lower end for admission of air thereto and having openings adjacent its upper end for supplying heated secondary air to the zone of combustion.

7. In a gas burner, an air manifold, a gas manifold within the air manifold in concentric spaced relation thereto, burner tube assemblies extending from the manifolds at an inclination upward and inward and each comprising an air tube communicating at its lower end with the air manifold

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