US2215983A

US2215983A - Gas burner

Info

Publication number: US2215983A
Authority: US
Publication date: 1940-09-24
Anticipated expiration: 1957-09-24

Description

' sept. 24, 1940. A. Smm

GAS BURNER Filed Feb. 18, 1938 Patented spt.'z4,1s4o

'UNITED STATES Gas BURNER Auburn smith, columbus, ohio Application Februar-yrs, 193s, ser1a1N0.'191,21 4 v u V` (01.158-99) 1 Claim.

This invention relates .toA gas burners and has particular reference to gas' burners .ofthe low- -pressure jet inspirator type wherein fuel gas,

Y. under ordinary main pressure, is the motivating fluid and atmospheric air the induced fluid, the

- construction of the burner providing automatically for the proper mixing and proportional blending of the fluids comprising the final combustible.

mixture.

An outstanding object of the present invention Sresides in theprovision of a simple and efficient gas burner primarily constructed and adapted' for use in ordinarycoal burning furnaces ofthe type widely employed in connection with residence heating systems.

The convenience and usefulness of fuel gas as a heat source in the/operation of house heating systems are well recognized.. However, in most localities, the relative higher cost of fuel gas in comparison with solid fuels, such as coal or coke, militates against its general use. Therefore, during cold winter periods, when fuel demand is heavy, it is considered desirable by many to burn the vmore economical solid fuels. but during periods of milder temperature,whenv solid fuel fires arel difficult and troublesome -v4to maintain, it is quite desirable to use gas as the source of heat. Hitherto, thisfselected and seasonal use of gaseous and solid fuels has been accomplished by the employment of either separately constructed furnaces or by means of combination units havingspaced combustion chambers specifically adapted and constructed for the fuels burned therein. Such equipment, however, is too costly to admit of popular use thereof, since installation expenses are high and, moreover, a considerable amount of floor space is required which, quite often, is not readily available.

It is, therefore, one ofthe mainobjects of the f present invention to provide an improved 'gas burner of sturdy, simple and economical construction which may be readily installed Vin or removed frorn the fuel burning chamber of an ordinary coal furnace, this being accomplished without involving any material `change or alteration in the constructional features of the furnace so that, in a minimum of time and at low expense, such a furnace may be conveniently adapted for the efficient burning of either coal or gas.

Another object of the invention resides in the provision of an auxiliary gas burner for coal furnaces so constructed and mounted in the interior r letof the burner against the inner surfaces of `the furnace fuel bowl, whereby to quickly and- :taken through the furnace in the planeof its 25 my improved gas burner in its operating position 'in relation to the walls of the furnace fuel bowl;

PATENT oFFicE ofthe furnace Aas to cause circular orswirling impingement of the flames issuing from the outeconomically raise the temperature of the' heat 5 transferring .surfaces of the furnace through direct and prolonged contact of the gas burner flames therewith.

A still further object resides in a gas burner' havinga wide combustion range and one which 10 is not likely to back-fire even though the fuel pressure may be reduced to a minimum, to the end of providing a burner which maybe safely used and operated in the heating system of an ordinary residence without requiring undue at- 15 tention or the servlcesof a -skilled operator.

Further vobjects and advantages will become apparent as the description proceeds.

In the accompanying drawing:

Fig. 1 is a sectional perspective view taken 20 through an ordinary coal burning furnace and disclosing the operating position of the auxiliary gas burner comprising the present invention therein; Flg. 2 is ahorizontal sectional view fuel admitting door opening and disclosing in plan Fig. 3 is a horizontal lsectional' view taken through my improved gas burner. f 30 Fig. 4 is a transverse sectional view, the. plan of which being indicated by the line IV- IVof Fig. 5 is a similar view on thev line V--V of Fig. 3. f

While the invention is susceptible of various modifications and alternative constructions,=I have shown in the drawing and will herein de-y scribe in detail the vpreferred embodimentther y of, but it is to be understood that Ido -not there- 40 by intend to limit the invention tofthe-embodiment disclosed, but intend to cover all modifications and alternative 'constructions falling within the spirit and scope ofthe invention as expressed in the appended claims. 45

Referring more particularly to the drawngthe numeral I designates the outer casing of an ordinary hand-fired coal burning furnace. Provided within the casing is the usual ash pit 2, grates 3; a fuel receiving bowl 4, smokeiring 5 and a plenum chamber 6.' Normally solid fuels are introduced into the bowl 4 and are deposited on the grates 3 by being manually introduced into the furnace through the fuel admitting .l

opening the front of the latter being normally closed by ka removable door, not shown. The smoke ring 5 communicates with a flue 8 leading to a chimney or other point of smoke outlet, the flue being provided with the customary damper valve S, which may be set` to obtain desired draft conditions within the combustion chamber I0 of the furnace, formed by the bowl 4.

The gas burner II, comprising the present invention, has been particularly designed for use as an auxiliary heat-producing means in a standard coal burning furnace of the type set forth, in order that such a furnace may be con- /veniently and economically operated, especially during periods of relatively low fuel demand. In the specific form of the burner illustrated, the same comprises an air supplying duct I2, which preferably consists of inner and outer sections I2a and I2b, respectively, secured together as at I3, to form a continuous conduit of substantially uniform diameter throughout its length and open at both ends. The duct, as shown, is adapted to be positioned in the fuel admitting opening l of the furnace and preferably to one side thereof. In this instance, the exterior of the duct is equipped with a bracket I4 by which the duct may be conveniently positioned in one of the lower corners of the transversely rectanguiar opening l'. A

With the 4burner occupying the position disclosed in the drawing, the ordinary outer door or closure of the opening I is removed from the furnace casing, and a sheet or panel i5 of asbestos or other heat insulating material substituted therefor by which the front of the opening 1 is closed. The sheet or panel l5 is formed with an opening of sumcient diameter to receive the outwardly projecting end of the duct i2, as disclosed in Fig. 2.

The inner section Ic of the duct is disposed substantially within the confines of the combustion chamber I@ and is formed with an angulariy and downwardly directed burner exten,

sion I6, which lies closely adjacent to the inner wall of the bowl 4. The extension I6 has its longitudinal axis disposed at an angle of apn proximately 45 degrees to the longitudinal axis of the main body portion of the duct occupying and extending through the furnace opening l. The side walls of the extension converge slightly toward the inner end to provide a somewhat restricted outlet.

Disposed axially within the angularly extending portion I6 of the duct is an elongated mixer tube I'I of suitable form. In the present instance, the tube I1 is provided with an inwardly flaring passage of progressively increasing diameter toward the outlet end of the burner. The inlet end of the tube is smoothly rounded on a relatively large radius, as indicated at IB, while the outlet or discharge end of the tube is smoothly rounded on a relatively smaller radius, as indicated at I9. Open webs or spiders 20 are disposed in the angular extension I6 of the duct in order to effect the axial support of the tube I1 within the angular extension of the duct, and with the outer Walls of said tube spaced from the inner adjacent walls of the extension I6 to provide an annular and open-endedair space 2l for the travel of air through the'extension I6 around or exteriorly of the tube il.

Extending longitudinally of the main body portion of the duct is a gas supply pipe 22, which has its inner end threaded to receive a jet nozzle 23, the latter being formed with an angular head 24 which is disposed in spaced relationr from the inner end IB of the tube I'I but in axial alignment therewith.. It will be understood that the outer end of the head 2H may be provided with one or more restricted orifices for the discharge of a hydrocarbon fuel gas under city main pressure in the form of one or more inspirating jets.

In the operation of the burner, atmospheric air enters the open outer end of the duct I2, which projects beyond the contines of the casing I. Gas under suitable pressure issues from the orice or orices formed in the head 24 and passes under relatively high velocity into the enlarged inlet'end of the mixing tube I'l. An inspirator action is thus set up by which a cer. tain amount of primary air obtained from the interior of the duct is drawn 'into the tube I'l with the gas stream passing therethrough so that a primary fuel mixture, composed of fuel gas and a limited amount of air, is produced in the tube I1. Ordinarily this mixture does not burn in said tube because of its velocity of travel and the limited amount of atmospheric oxygen contained therein.- Final combustion, however, is obtained by the secondary air, discharged from the angular extension IB of the duct, combining with the primary mixture and with such oxygen that may exist in the atmosphere of the chamber I0. Combustion of the final fuel mixture, however, takes place following discharge of the gaseous iiuids forming the mixture from the angularly directed portion of the duct.

The combustion flames are so directed as to impinge the inner surfaces of the bowl 4 and travel in a generally circular path around the bowl, as disclosed by the arrows in Fig. 2. The flame is directed generally downwardly in the bowl by reason of the angular disposition of. the burner head. Preferably, a bed of ashes, as indicated at 25,'is maintained on the grates 3 in order to better regulate draft conditions within the combustion chamber of the furnace. In the operation of the burner, the ash pit door 26 of the furnace and its associated draft controls are kept closed.

Due to the angularity of the burner head and its position within the chamber II), prolonged flame travel is obtained due to the swirl of the flame in the bottom of the chamber ID. Also, improved heat transfer is secured due to the wiping actionof the hot gases of combustion directly contacting with the walls 'of the bowl 4. The walls of said bowl are uniformly heated by reason of the spinning motion of the burner flames and there exists ordinarily but an immaterial differential between the temperature of the bowl wall more closely adjacent the outlet of the burner and the wall on the opposite side of the bowl as regards said burner. Excess pressures within the chamber I0. which lmay exist at the time the operation of the burner is commenced, nd ready relief through the duct I2, without interfering with sustained combustion occurring at the outlet of the burner head within the chamber I0. The endof the gas supply pipe 22 disposed exteriorly of the furnace casing terminates in an elbow 2l and is united with a short pipe exten'- sion 28 in which may be arranged a thermostatically controlled valve 29. The extension 28, beyond the valve 29 is joined with a removable coupling 30 carried by a stationary gas supply pipe 3|. In the pipe 3i, there may be arranged a control valve 32, either manually or automatically regulated, to govern the delivery of fuel gas to the burner. Also, a pilot line 33 leads from the pipe extension 28 to the head of the burner, so that a constant supply of gas for pilot purposes may be provided at the head of the burner to insure continuity of operation. i

A thermostat element 34, governing the operation of the valve 29, is disposed in or contiguous to the pilot flame so that if the latter should become extinguished, the valve 29 will be closed to prevent the accumulation of unburned fuel gases in the chamber I0. The flow of air into the outer end of the duct I2 may be controlled in volume by the inclusion of an adjustable shutter 35 which is mounted for 'movement toward and away from the open outer end of the duct. The adjusted positions of the shutter may be maintained by the use of .a set screw 36.

To install the gas burner comprising the presenrI invention in a coal burning furnace of the type set forth, it is merely necessary to remove the usual door closing the fuel admitting opening 1. This may be readily accomplished by taking the door oi its hinged mountings. The gas burner is then positioned in said opening and in the furnace as disclosed in Fig. 2 and the asbestos plate or panel l5 applied to seal the entrance to the opening 1. The gas supply pipes 22 and 28 form constituent parts of the burner assembly and it is therefore merely necessary to operate the coupling to unite these pipes with the sta.-

tionary gas pipe 3| to complete the installation. Similar convenience is of course obtainable in the matter of removing the burner from the furnace. Usually with the gas supply pipe 3| in position, it is only a matter of a few minutes time to either make or remove the installation.

What is claimed is:

In apparatus for firing a house-heating furnace With fuel gas instead of solid fuel, the furnace having a repot and a redoor opening; the combination of an air supply conduit extending through said redoor opening and terminating adjacent said iirepot, an air nozzle extending toward the rcpot from said conduit and forming in effect a continuation of the latter for supplying secondary air, a mixing tube interiorly of said air nozzle arranged to discharge a mixture into said repot, a gas supply pipe Within said conduit, terminating adjacent said air nozzle and arranged to direct fuel gas ,into said mixing tube, and means scaling the conduit and firedoor `against inflow of air therebetween; whereby to induce primary air from said conduit into said mixing tube to provide a combustible mixture issuing from the outer end of the tube, and to direct secondary air from said conduit through said air nozzle adjacent the outlet of the mixing tube.

AUBURN SMITH.