US2549427A - Gas burner assembly - Google Patents

Description

April 17, 1951 A. cLARKsoN GAS BURNER ASSEMBLY '2 Sheets-Sheet l Filed March 15, 1948 QN E. NN MN l N V EN TOR. @Zw/ Ya/*ism B Y GAS BURNER ASSEMBLY Filed March l5, 1948 2 Sheets-Sheet 2 IN V EN TOR.

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l Patented Apr. 17, l1951Y YUNITED STATES PATENT orties l GAS BURNER ASSEMBLY lick Clarkson, Itasca, Ill., assigner of one-half l to Vapor Heating Corporation,l Chicago, Ill., a

corporation of Delaware v;

Application March 15, 194s, serial'No. M951 1 vide an improvedrgas burner assembly which is. so constructed aS to eifect eicient burning of a large volume of gaseous fuel in` a relatively small combustion chamber.

The invention may be described briefly as comprising a re ring A and a fuel nozzle structure B surrounding the` same which are positioned Within an air pressure chamber C in a position to direct the ,products of combustion downwardly. vinto thel boiler D. A cylindrical member E defining a combustion. chamber is supported above the ring A and fuel nozzle with the lower end of the cylinder E being spaced from the upper edge of the re ring A so as to provide 'an air passage F communicating with the air chamber C. The cylindrical member E is supported at its upper end within an air dome G which dome is also in Ycommunication with the air chamber C. A pilot nozzle I-I extends into theupper portion of the combustion chamber so as to direct apilot iiame'downwardly therein. The said nozzle communicates through air passage I with thesaid air pressure chamber C.

. 'Gaseous fuel from nozzle structure B, together with a circular sheet of combustion air, is delivered upwardly into the combustion chamber along the circular wall thereof. Secondary air -is delivered into the upper central portion of the combustion chamber' and `moves vdownwardly within the upwardly moving flame. The central core of air, under pressure, moving in opposition to the surrounding sheet of gas and air, mixes with the burning gaseous mixture and imparts toroidal movement to the burning mixture. The high turbulence maintained in the combustion chamber and the vertical looped path or toroidal movement of the flameand partially ignited fuel brings the partially ignited fuel into repeated mixing engagement with additional air and thereby insures complete combustion` of the fuel as it moves in its circuitous course from the combustion chamber into the boiler D. The said combustion air is highly heated because of the arrangementv of the combustion chamber within the air chamber C and thereby increases the efficiency of combustion.

A pilot nozzle H, for directing a pilot flame downwardly into the combustion chamber, ex-

9 Claims. (o1. 15841) tends into the upper portion of the Ychamber at one side of the vertical center thereof so as to insure contact of the pilot ame with the combustible products at all times. The said pilot nozzle, during high flame operation of the burner, receives air under pressure through the passage I so that the pilot ame assumes a long pencil-like character. However, when the gas and air pressure is shut orf from the main burner the pilot flame is reduced in length, but will remainlighted in readiness for renewed high flame operation. During the. inactive period of the burner, a weighted valve'Jl in the air passage IV drops toits dotted line position so as Vto admit outside air to be drawn into the passage by theinspirating action of the gas jet K and thereby provides suflicient air to support combustion at the discharge end of the pilot nozzie. However, as soon as renewed normal operation is resumed the air pressure in chamber C enters the passage I and thereby closes the weighted valve J.

The hot products of combustion from the chamber E move downwardly through 'the fire l ring A andv pass` through the" heating coils of the boiler into the spaceL, between'the coils and the outer casing M, and are discharged through the smoke boxN to asuitable Smoke stack not shown. Y Y

Anotherobject of the invention is to provide an improved gas burner assembly constructed and adapted to operate in the manner hereinl above brieiiy described.

Another object yis to provide, in a gas burner of the above character, an improved construction whereby the combustion air is preheatedto a high degree and introduced into the combus- -tion chamber at locations to create high turbulence within the combustion chamber and thereby insure thorough mixing of the gaseous fuel yand air.

Another object isk to provide a construction in which the combustion air is utilized to prevent overheating of the walls of the combustion chamber.

Another object is to provide, in a'gas burner of the above character, a long pencil-like pilot flame which is projected downwardly into the combustion chamber at a location spaced from the vertical center thereof so as to insure ignition of the-gaseous fuel.

Another robject is to provide air control means for the pilot flame, whereby air-under pressure is supplied to the pilot nozzle during high fiame operation of the burner and whereby a reduced 3 quantity of air is supplied to the pilot nozzle during inactive periods of the main burner.

A further object is to provide improved arrangements and constructions which facilitate ready assembly of the several parts and which facilitate ready dismantling of the structure when it is necessary or desirable to repair or replace parts thereof.

The invention is illustrated in the accompanying drawings wherein:

Fig. l is a vertical section showing a gas burner assembly constructed in accordance with this invention supported on the upper portion of a water-tube boiler.

Fig. 2 is a plan View of the burner structure shown in Fig. l. y

Fig. 3 is a fragmentary' sectional view taken on line 3 3 of Fig. 2 to illustrate the manner in which the gaseous fuel is delivered to the fuel nozzle, and

Fig. 4 is a fragmentary View in side elevation illustrating a valve holding means for holding a manually adjusted. valve in a desired predetermined position.

Referring now to Fig. 1 of the drawings: The gas burner assembly, as previously indicated, is suitable for use in connection with steam generators and hot water boilers of various constructions. It will be understood therefore that the specific form of steam generator herein shown is for purpose of illustration and is not intended as a limitation on the scope of use of the invention disclosed.

The generator D comprises a plurality of substantially helical pipe coils Hl, Il, i2, i3 and I5. arranged co-axially about the central vertical axis of the generator. The several coils are arranged so that the loops of one coil assume a staggered relation to adjacent coils, as shown in Fig. l, so that the hot gases delivered through the fire ring A and into the heat space of the generator will pass between the coils of the generator and thereby take a sinuous path through the several banks of heating coils. rhis arrangement of the heating coils in staggered relation insures maximum surface contact of the hot gases with the coils. The gases of combustiion after passing between the coils of the generator' enter the space L and thereafter pass through the smoke-box N and flue opening O.

The burner assembly includes an air chamber C whichy in the present embodiment, is of circulay configuration and provides a closure for the annular space L of the steam generator D. The said air casing is provided with a partition l5 which separates the casing into the said air chamberrC and a smoke-box N. The said partition i5, as viewed in plan (Fig. 2), provides a crescent shaped smoke-box to facilitate ready discharge of the spent products of combustion after they pass through the coils of the heatexchanger. The smoke-box N is provided with flue opening O vwhich may be connected to a suitable vent for carrying away the products of combustion. By positioning the partition l5 in the manner indicated so as to separate the air chamber from the smoke-box, the exhaust products entering the smoke-box serve, to some extent, to apply heat to said partition I5 and thereby heat a portion of the air contained in chamber C,

The nre ring A is preferably composed of molded refractory material i6 and is positioned at a location for directing the hot combustion gases into the heating space of the generator D.

In the present case, since the generator D is formed to operate on a down draft principle, the fire ring I6 is positioned on the upper end of the water coils of the generator. In order to support the said ring in proper position, a conical base member l'l seats on the coils of the generator so ras to provide a fiat surface for the base portion of the ring I 6. The fire ring extends into the air chamber C and the open upper end of the ring' is fiared outwardly as shown at I8 so as to provide a conical configuration in cross section. The upper edge portion of the said fire ring is provided with an upwardly outwardly inclined metallic flange i9 which serves as an air defiector in the manner hereinafter described. A main'fuel nozzle B surrounds the fire ring A and is provided with a plurality of upwardly projecting jet elements 20 arranged in spaced relation to each other and positioned to discharge a gaseous fuel upwardly into the combustion chamber, the gaseous fuel beingdelivered to the main fuel nozzle through a supply pipe 2i and downwardly inclined connection 22, as shown in Fig. 3 of the drawings.

The combustion chamber' is defined by a cylindrical casing E which is suspended at its upper end from an air dome structure G. The lower edge portion 23 of the casing E is flared outwardly so as to direct air from the chamber C into the passage F around the several jet elements 20. The upwardly and outwardly inclined flange I9 of the re ring serves to deflect the air inY passage F in a direction toward the circular side wall of the combustion chamber at a location adjacent to the discharge ends of the jet elements 2li and thereby insure thorough initial mixing of the air and gaseous fuel as it enters the combustion chamber. This mixture of gaseous fuel and air is directed upwardly into the combustion chamber along the vertical wall thereof and -is thereafter mixed with air introduced into the combustion chamber at the upper end thereof. The upper end of the combustion chamber casing is in the form of a truncated cone 24 which functions as a baiile for directing the upwardly moving gaseous mixture inwardly toward the center of the combustion chamber where it is mixed with the air introduced into the upper-endportion of the combustion chamber. The said upper end 24 of the combustion chamber is secured to a cap plate 25 of similar truncated cone form, but is spaced from the under surface thereof by means of spacers 26 so as to provide an air passage 2 for directing air upwardly over the top sheet 24 of the combustion chamber and into the upper portion of the chamber through the central opening 2B. The said cap plate is connected by means of a cylindrical portion 29 to the inner surface of the top portion of a casing 3G defining the air dome G. A manually adjustable sleeve valve 3E surrounds the cylindrical portion 29 and is provided with openings 32 adapted to be moved into register with corresponding openings 33 in the said cylindrical portion 29. rEhe sleeve valve is held in its suitably adjusted position by means of wing nuts SI1-34 which engage bolts extending up through elongated slots 35-35 in the top portion of the air dome G.

The cap sheet 25 is preferablyl formed so that its lower edge extends into the air passage 36 between the vertical wall structure of the combustion chamber and the vertical wall structure 'di of the air dome G, so as to direct a major portion of the air from passage 36 into lthe passage 21 and thence into the upper end-of the combustion chamber. However, a substantial portion of air passes around the lower edge of the cap sheet 25 and enters the cylindrical .portion 29 through the sleeve valve controlled openings 33. It is'by means of the sleeve valve 3| that the amount of air delivered into the upper end of the combustion chamber may be varied to suit the pre-- The gaseous fuel introduced into the combus- Y tion chamber is ignited by means of a pilot flame 40. The pilot flame 40 is maintained by a mixture of gas and air which is discharged from the pilot nozzle H. This nozzle is of known construction and extends into the combustion chamber through a plate 4I which is removably secured to and forms the top plate of the air dome G. When the apparatus is operating with fuel delivered from the main fuel nozzle B air, under pressure, is delivered to the pilot nozzle through the passage I sothat the fuel and air mixture will be discharged into the combustion chamber with considerable velocity from the .pilot nozzle H and thereby form a relatively long pencil-like flame for maintaining the gaseous mixture ignited within the combustion chamber. The amount of pressure air supplied to the pilot nozzle may be controlled by adjusting a Valve 42 positioned in said passage I. The said valve 42 is held in its adjusted position by means of a ratchet bar 43 positioned to engage the operating arm 44 of the said valve 42. When the operation of the main fuel nozzle B is discontinued the air pressure is relieved and the pilot flame is reduced in length but it remains lighted so as to be available for high flame operation of the main fuel nozzle B. During the inactive period of the main fuel nozzle B the weighted valve J assumes the position indicated in dotted lines in Fig. 1 so as to admit outside air into thepassage I through an opening 45, the ar'being drawn through said opening by the insp-irating action of the gas discharged from the jet K into the supply tube 46 leading to the pilot' nozzle H.

Summary of operation When the burner assembly is initially put into operation, gas is delivered through jet K into the'supply tube 45 of the pilot nozzle H. During this initial operation, the valve J is in the dotted line position indicated'in Fig. l. Consequently, external air is drawnthrough opening 45 by the inspirating action of the jet K to provide the initial mixture for the pilot flame, This initial mixture is ignited by means of an electrical discharge between the lower ends of a pair Iof electrodes 47,43. This electrical ignition is operated only normally during the initial starting of the burner, since the pilot flame, when once ignited, thereafter serves to. ignite the fuel discharged from the main fuel nozzle."

' During normal-'operation of the burnergas is delivered from the` jet elements' 20 of the main fuel nozzle so as to flow upwardly along the vertical wall of the cylindrical combustion chamber. Primary combustion airis delivered upwardly 6 through the passage F so as to mix with the gas from the nozzle elements 20 and flow upwardly along the vertical wall of the combustion chamber. Additional air from the .air chamber C moves upwardly along v:the outer surface ofthe combustion chamber El so as to beco-me heated and is directed, in the form of a blanket of air, through the passage 21 overlying the top sheet 24 lof the combustion chamber and also through the valved openings 33 in the cylindrical portion 29. This air creates turbulence in the combustion chamber and moves downwardly in the form of a turbulent stream. It engages and mixes with the mixture of gas and air which is deflected inwardly by the top sheet 24 of the combustion chamber and thereby imparts to the gaseous mixturea series of vertical loop movements. The series of vertical loops formed by the flame and partially burned fuel causes the `partially burned gases to be brought into contact with additional air sufficient to support complete combustion. The hot products of combustion are then moved downwardly through the re ring A, thereby heating the ring and insuring combustion of any gaseous fuel at this location. The said products continue downwardly into the heating space defined by the inner coils I0 of the generator D and pass through the circuitous passages defined by mediate the coils and the outer casing M and are,

discharged through the nue opening O.

I claim: l. A gas burner assembly for delivering hot gases of combustion into a heatexchange apparatus and comprising a casing dening a chamber for containing air under pressureja cylindrical casing defining a combustion chamber having an end wall at one end and open at the other end and having its open end extending into said air chamber, whereby air enters the combustion chamber through said open end and 'whereby the cylindrical wall of the combustion chamber transfers heat to the air within said air chamber; a main fuel nozzle for delivering gaseous fuel into the combustion chamber ad jacent the cylindrical wall thereof through said open end of the combustion chamber casing; an air dome surrounding the end portion of the combustion chamber casing having said end wall, but spaced therefrom to provide an air passage communicating with said air chamber; an annular cap plate overlying the said end wall of the I combustion chamber casing and providing a passage for directing air under'pressure into the combustion chamber through an opening in said end Wall, whereby the last mentioned air mixes thoroughly with the gaseous fuel and imparts toroidal movements thereto; a cylindrical portion yuniting the central portion of said cap plate with the air dome and provided with openings ydefining air passages for delivering additional and valve through the last mentioned passages into the combustion chamber.

2. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing defining a "chamber for containing air under pressure; a

cylindrical casing defining a vertical combustion chamber having an open lower end extending into said air chamber, whereby the air enters the combustion chamber through said lower end; means providing an upper end wall for said combustion chamber and having a central opening therein; a main fuel nozzle for delivering gaseous fuel into said' combustion chamber through said open lower end of the combustion chamber casing; means for removably supporting the combustion chambei' from the upper portion of said air chamber casing and defining an air passage for directing air under pressure from said air chamber into the upper end of said combustion chamber through said central opening, whereby the last mentioned air mixes with the gaseous fuel and imparts vertical whirling movements thereto; and means for directing a pilot flame into the upper portion of the combustion chamber to ignite the fuel and air therein.

3. A gas burner assembl;7 for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing defining a chamber for containing air under pressure; a cylindrical casing defining a vertical c mbustion chamber operi at one end and having its open end extending into said air chamber, to admit air from said air chamber into said combustion chamber; a. main fuel nozzle for delivering gaseous fuel into the combustion chamber through said open end thereof; means communicating with the said air chamber for directing air under pressure into the upper end of said combustion chamber, whereby the last mentioned air mixes with the gaseousrfuel and imparts vertical whirling movements thereto; a fire ring for directing the hot combustion gases from the combustion chamber into the lieatexchange apparatus; a partition in the said air chamber extending partially around the combustion chamber casing and defining a smoke-box for receiving the spent gases of combustion from the heat-exchange apparatus.

4. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing dening a chamber for containing air under pressure; ,a cylindrical casing defining a vertical combustion chamber open at its lower end and having its open end extending into said air chamber to admit air from said air chamber into the combustion chamber; a main fuel nozzle for delivering gaseous fuel into the said combustion chamber through said open end thereof; means com municating with said chamber for directing air under pressure into the uppe end of said combustion chamber, whereby the last mentioned air mixes with the gaseous fuel and imparts vertical whirling movements thereto; a pilot nozzle extending into the upper portion of the coinbustion chamber for delivering a pilot flame downwardly therein to ignite said gaseous fuel, a fuel jet element for delivering gas into the pilot nozzle; means denning an air passage `cornmunicating with said air chamber for directing air under pressure to said pilot nozzle; and a manually adjustable valve for varying the amount of the last mentioned air.

5. A gas burner assembly for deliveringhot gases of combustion into av heatexchangev apparatus and comprising a casing defining a chamber for containing air under pressure; a cylindrical casing defining a vertical combustion chamber open at its lower end and having its open end extending into said air chamber to admit air from said air chamber into the combustion chamber; a main fuel nozzle for delivering gaseous fuel into the said combustion chamber through* said open end thereof; means communicating with said chamber for directing air under pressure into the upper end of said combustion chamber, whereby the last mentioned air mixes with the gaseous fuel and imparts vertical whirling movements thereto; a pilot nozzler extending into the upper portion of the combustion chamber for delivering a pilot flame downwardly therein to ignite said gaseous fuel, a fuel jet element for delivering gas into the pilot nozzle; means deningan air passage communicating with said air chamber for directing air under pressure to said pilot nozzle and having also an air port therein for admitting atmospheric air into the last mentioned passage; a pressure actuated valve positioned in said air passage and adapted to open to admit said atmospheric air when the air pressure within said passage falls below a predetermined point, whereby the pilot flame is supplied with combustion air drawn into the passage through said port by the inspirating action of the fuel jet delivered into said pilot nozzle.

6. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing defining a chamber for containing air under pressure; a cylindrical casing dening a combustion chamn ber open at one end and having its open end extending into said air chamber, whereby the cylindrical wall of the combustion chamber transfers heat to the air within said air chamber; a fire ring arranged concentric to the axis of the combustion chamber and extending into said air chamber and into said open end of the combustion chamber to deliver the hot combustion. gases from the burner into the heatexchange apparatus and denning the inner perimeter -of an annular passage for delivering an annular stream of air into the combustion chamber through the open end thereof; a main fuel nozzle surrounding said fire ring for delivering gaseous fuel into the combustion chamber through said annular air passage; means communicating with said air chamber and with the other end of the combustion chamber for directing air under pressure into the combustion chamber in a direction opposite to the air delivered through said annular passage, whereby the said air under pressure mixes with the annular -stream of air and gaseous fuel and imparts toroidal movements thereto; and a pilot nozzle extending into the combustion chamber for delivering a pilot name therein to ignite said fuel and air.

7. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing defining a chamber for containing air under pressure; a cylindrical casing defining a vertical combustion chamber open at its lower end and having its open end extending into said air chamber, whereby air enters the combustion chamber through said open end and whereby the cylindrical wall of the combustion chamber transfers heat to the air within said air chamber; a main fuel nozzle in the form of a ring for delivering gaseous fuel into the combustion chamber adjacent the cylindrical wall thereof through said open end of the combustion chamber casing; an air dome surrounding the upperY portion of said combustion chambervcasing and communicating with said air chamber and with the other Vend of the combustion chamber for directing air under pressure into the combustion'chamber in a direction opposite to the air and gaseous fuel delivered through the open end thereof, whereby the Ylast mentioned air mixes with the gaseous fuel and imparts toroidal movements thereto; and a pilot nozzle extending into the combustion chamber for delivering a pilot flame therein to ignite said fuel and air.

8. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing defining al chamber for containing air under pressure; a cylindrical casingdefining a combustion chamber having an end wall at one end and open at the other end and having its open end extending into said air chamber, whereby air enn ters the combustion chamber through said open end and whereby the cylindrical wall of the combustion chamber transfers heat to the air within said chamber; a main fuel nozzle formed with a series of discharge openings disposed in circular arrangement for delivering gaseous fuel into the combustion chamber through said open 'end of the combustion chamber casing; an air dome surrounding the upper portion of the com-A bustion chamber casing having said end wall, but spaced therefromto provide an air passage communicating with said air chamber; means defining a central opening in said end wall of the combustionchamber; an annular cap plate overlying the top portion of the combustion chamber casing and providing a passage for directing air under pressure through said central opening into the combustion chamber, whereby the last mentioned air mixes thoroughly with the gaseous fuel and imparts toroidal movements thereto; and a pilot nozzle extending into`the combustion chamber for delivering a pilot flame therein to ignite said fuel and air.

9. A gas burner assembly for delivering hot gases of combustion into a heat-exchange apparatus and comprising a casing dening a chamber for containing air under pressure; a

cylindrical casing defining a, combustion chamber open at one end and having its open end extending into said air chamber, whereby air enters the combustion chamber through the said open end and whereby the cylindrical Wall of the combustion chamber transfers heat to the air within said air chamber; a re ring of molded refractory material extending into said air charn` ber and into said open end of the combustion chamber to deliver the hot combustion gases from the burner into the heat-exchange apparatus; a main fuel nozzle surrounding the said fire ring for delivering gaseous fuel into the combustion chamber through said open end of the combustion chamber casing; means defining a central air passage leading into the other end of the combustion chamber; means communicating with said air chamber for directing air under pressure into the combustion chamber through said central air passage, whereby the last mentioned air mixes with the gaseous fuel and imparts toroidal movements thereto, and means extending into the upper portion of the combustion chamber for igniting the mixture of fuel and air therein.

ALICK CLARKSON.

REFERENCES CITED The following references are of record in the iile of thispatent:

UNITED STATES PATENTS

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