US1960842A - Burner - Google Patents

Description

A. J. GILBERT May 29, 1934.

BURNER Filed April 1o, 1931V 2 Sheets-Sheet 1 by@ 'w May 29, 1934- A. J. GILBERT 1,960,842

BURNER Filed April 10, 1931 2 shets-sheet 2 y 7 M7 Haba Patented May 29, 1934 UNITED lSTATES PATENT OFFICE The Silent Glow Oil Burner Corporation, Hartford, Conn., a corporation of Connecticut Applicatimnpril 1o, 193i, serial No. 529,221 13 Claims. (Cl. 158-11) This invention relates to'burners and more par ticularly, though not exclusively, to what are commonly termed combustion. tube burners. The latter are usually provided with one or more combustion chambers having perforated tubular Walls through which air enters to mix with fuel vapor ascending from a fuel-space at the bottom of the chamber, the mixture being burned in the combustion chamber and a blue flame issuing from lo the upper open end thereof. Such burners are commonly employed in connection with a single fuel supply source, such as oil or other liquid fuel, which is supplied to or has connection with a fuel groove or trough immediately beneath the combustion chamber. l

The objects -of the invention among other things are to improve the construction of burners of this type, increase their utility by making them adaptable to a wider range of service and to decrease the starting interval or period required for preheating when employed with liquid fuel.

These and other objects of the invention will be best understood by reference to the following description when taken in connection with the accompanying illustration showing one specific embodiment thereof, while its scope willbe more particularly pointed out in the appended claims.

For descriptive purposes the liquid fuel is herein referred to as oil, although other types of liquid fuel may be employed.

In the illustrated embodiment of the invention, the burner is so constructed that it Will operate with complete effectiveness for either long or short intervals from a supply of either oil or gaseous fuel. While it'has certain constructional advantages which materially improve its operation, as hereinafter pointed out, when supplied with oil alone and without a gaseous fuel supply, in the disclosed embodiment of the invention the con- 40 nections are such that either oil or gaseous fuel may be supplied at will so that the burner may be operatedexclusively from a source of liquid loil supply or from a source of gaseous fuel supply, or its operation at one time when supplied with gaseous fuel may be followed Without interruption by its operation with oil, or vice versa.

The ordinary combustion tube burner, when supplied solely with oil, has certain disadvantages which limit its field of usefulness. In starting a burner of this type from a cold condition it is necessary to preheat the burner walls before finally turning on the full continuing supply of the oil so`that some vaporization of the oil will take place when it reaches the fuel space and the rising vapor will form a combustible mixture with the incoming air in the combustion chamber.

One common method of preheating is to pro vide the fuel groove with an asbestos or other wick,` which is rst saturated with oil or other priming fluid and then lighted by a taper. After an interval of preheating suiiicient to cause a vaporization of a portion of the oil reaching the fuel groove, the supply is then turned on. As the tempei'ature rises, the walls of the groove and adjacent passages become more highly heated and an increasingly greater proportion of the oil reaches the groove in vaporized form and finally,

after the lapse of a substantial interval, the oil Y reaching the fuel space or spaces is completely vaporized and an intensely hot blue ame results. 'Ihe prolonged interval required for the preheating before the burner can be brought toits full heating capacity, which may be termed the starting interval, is a serious drawback to the more general use of this type of burner. -Due also to the fact that the oil is delivered in 'quid form and must be vaporized by the heated surrounding walls of the burner before it can be ignited in the combustion chamber, the heating effect of a burner of given size is limited and, while it may be ample for ordinary purposes, if an especial occasion arises calling for a more intense heat, the burner cannot be forced beyond a given point by merely increasing the rate with which oil is supplied. In the described embodiment of the invention, lf it is desired to operate the burner with oil, the starting interval may be cut down to a relatively short period by first turning on and igniting the gas from the source of gas supply which willimmediately develop the full heating capacity of the burner and will quickly raise the temperature of the burner Walls to a point sufficient to fully vaporize the oil. Accordingly the latter, without the long delay heretofore necessary, may be quickly turned on and the gas shut 01T, almost immediately reaching the full oil-hea ng capacity of the burner under the supply of oil, thereby eliminating in large measure the disadvantage due to a prolonged starting interval.

On the other hand, where it is desired usually to operate the burner under oil but at times to operate it under conditions of more intense heat than could be obtained by liquid fuel, the latter 1f; may be shut olf and the gas turned on to force the burner beyond Aits oil heating capacity and to give whatever degree of flame may be called for.

The construction of the burner which qualifies ,other by a series of webs 17, ber, and providing for an ring-like flange 25 spaced it to burn either type of fuel adapts it to. a wide range of conditions. If gas is readily available and relatively economical it may be employed primarily with gas, andA oil maybe drawn from a source of oil supply only on those occasions when, as often happens, the gas supply may fail or be inadequate. If, as is usually the case, oil is more economical than gas, the burner may be primarily operated from the source of oil and operated with gas only for preheating or when the oil supply is depleted or not available, or when a special occasion arises for forcing the burner beyond a heating capacity which is obtainable from the oil. On the-other hand, the burner may sively with gas, as circumstances may demand.

In the drawings:

Fig. 1 is a central, longitudinal section in elevation, partly broken away, showing one form of the invention applied to a common type of combustion tube burner;

Fig. 2 is an end view, on a somewhat larger scale, showing the air and gas mixing valve;

Fig. 3 is a plan view of the burner base locking from above;

Fig. 4 is a similar view looking from beneath;

Fig. 5 is a sectional detail on the line 5-5 in Fig. 3; and

Fig. 6 is a similar section on the line 6-6 in Fig. 3.

Referring to the drawings and to the embodi- :ment of the invention which is here submitted for illustrative purposes, one of the many forms which the invention may assume is shown, by way of example, as applied to a combustion tube burner of a well-known oil fed type. It is to be understood, however, that the same has application to oil or other liquid fuel burners of widely different form.

Referring first to the oil burning provision for the burner, the latter is provided with a base plate 11 in the form of a casting having an outer, generally annular portion 13 and an inner, concentric, annular portion 15 connected one to the herein four in numannular admission space 19 between the two annular members of the base, interrupted only by the webs. As indicated in Fig. 3, the base may be formed integrally with asimilar duplicate base member', one of the two burner structures only being herein shown.

The inner member 15 is provided with a central air admission opening 21 surrounded by an upstanding, ring-like flange 23, the outer edge of the inner member also lhaving an upstanding, from but concentric with the flange 23. The flanges 23 and 25, together with the connecting wall of the base casting, form a relatively wide annular compartment or channel, on the bottom of which there is provided a raised annular lip 27 extending completely around the channel and separating the latter into-an outer fuel space defined by the groove 29, and an inner vaporizing space 31 between the lip 27 and the flange 23, to which vaporizing space oil is adapted to be delivered by the pipe connection 33 through the opening 35 in the bottom wall of the vaporizing space. The annular lip 27 constitutes a dam or baille which normally prevents the flow of oil in liquid form from the supply opening 35 to the fuel groove 29, the passage of vaporized oil taking place, however, without hindrance over the top of the raised lip. The bottom of the vaporizing space be operated at will exclusively by .oil or exclu-A Within the annular lip constitutes a flow plate over which any liquid entering the burner must flow and by which, when the burner is heated, it is readily vaporized.

Herein the outer annular member 13 of the base casting is also constructed to present an outer fuel groove 37 formed between the upright spaced annular flanges 39 and 41, the'outer fuel groove being of lesser radial width than the groove between the flanges 23 and 25 but of approximately the same width as that of the fuel space 29 between the flange 25 and the lip 27.

The outer fuel groove is connected to the inner groove by means of supply ducts 43 formed in the webs 17, so that free circulation takes place throughout both fuel grooves of vaporized oil supplied from the vaporizing space.

The top of the vaporizing chamber 31 is closed, except for the direct escape of vaporized oil to the fuel space 29, by a removable annular cover plate 45 (Fig. 1) formed preferably of thin sheet metal, such as chromium steel, the inside edge of the -plate having a down-turned flange to seat on the upper edge of the base flange 23 with a preferably close fit. The walls of the cover plate extend outwardly, and herein also downwardly, over the vaporizing compartment and over the annular lip 27, but are spaced vertically from the latter to provide an annular vspace from the vaporizing compartment to the fuel space so that any vaporized oil may pass directly over the lip, between the latter and the cover plate and into the fuel space 29.

Above the lip 27 the cover plate has a downwardly extending flange provided with an outturned lip on which there is supported a perforated sheet metal cylinder 47 (Fig. 1) constituting the inner one of the combustion tubes. A similar but larger concentric cylinder 49 is removably seated on the outer shouldered edge of the flange 25 so that there is provided between the two cylinders the elongated combustion chamber 51 aligned with and constituting an extension of the underlying fuel space 29. The concentric, spaced, perforated sheet metal cylinders 53 and 55 are likewise removably seated on the shouldered edges of the flanges 39 and 41, respectively, providing between them the combustion chamber 57 having a relation to the outer fuel space 37 similar tp that of the combustion chamber 51 to the fuel space 29. It will be understood that the perforations in the Walls of the cylinders may be of any size, shape or arrangement to provide suitable air admission openings for the combustion chambers, and are preferably distributed throughout the entire surface thereof.

A removable, annular, cover plate 59 is provided with its edges resting on the tops of the sheet metal cylinders 49 and 53 to close the top of the annular air space therebetween, and a disc-shaped closure 61 with its edges resting on the upper edges of the cylinder 47 is similarly provided to close the top of the central air cham-- ber, leaving, however, annular openings in the tops of the two combustion chambers 51 and 57 separated from the latter by the bottom wall of the channel. A second annular' outer gas chamber is similarly formed immediately beneath the outer fuel groove 37, being separated therefrom by the bottom wall of that groove.

The outer gas chamber 65 is connected to the inner chamber 63 by supply ducts 67 (Figs. 1 and 5l formed one in the lower part of each of the four webs 17, so that gaseous fuel may circulate freely from one chamber to the other. To supply gaseous fuel to the two gas chambers, one of them, and herein the inner chamber 63, is connected to the gas supply pipe 69 (Fig. 1) which in turn is connected through the control valve 71 with a source of gaseous fuel supply, which latter may be the ordinary service main, or a gas containing storage tank in which the gas is maintained under pressure, or any other suitable source.

When the burner is operated under gaseous fuel, the latter is burnedin the fuel grooves, and for this purpose the bottom wall of each groove 1s provided with one or more burner orifices. Such orifices are herein presented by ducts or small openings 73 distributed in spaced relation throughout the bottom of each groove, but they might be in the form of slots or otherwise, and

-the size, number and arrangement of these openings may be widely varied.

In order to secure the maximum heating effect of the gas flame on the base casting and the walls of the vaporizing space and fuel groove when the gas is employed to -preheat the burner prel1m1- narily to turning on the oil, it is desirable that the gas should burn close to the bottom of the fuel grooves. To provide for the entrance into the fuel grooves from the gas chambers of a combustible gaseous fuel so that it will ignite and burn immediately on entering the groove and lts heat will be most effective for raising the temperature of the base casting, the gas entering the chamber 63 from the supply pipe 69 is caused rst to pass through any suitable vair and gas mixing device, such as the mixing tube 75, which is attached to the bottom of the casting and opens into the gas chamber 63. The lower end of the mixing tube has the air supply opening 77 controlled by the valve plate 79 so that the amount of air supplied may be regulated. The gaseous fuel, therefore, entering the chamber 63 is in the form of a mixture of gas and air, further mixture of which takes place in circulating through the chambers 63 and 65, so that it issues from the burner orifices in the form of a combustible mixture which, when ignited, burns in the fuel grooves close to the bottom walls thereof.

The oil pipe connection 33 is connected to a source of oil supply which may comprise an elevated tank or the like combined with any one of the feeding. devices customarily employed with burners of the combustion tube type and which provide for the flow of oil to the burner from some definite height or level capable of being accurately regulated so that the flow of oil may be maintained at a predetermined level over the 'bottom of the vaporizing space 31 in the burner.

Such tanks and regulating devices are of common construction and are not herein shown.

It will be obserr-fed't-hat the walls of the annular air admission space 19 are curved or flared at the bottom so as toprovide a broadened, Iiared entrance mouth, this preventing any choking of the air supply to the overhead air chamber due to the depth of the base casting.

If it is desired to operate the burner with oil but to cut down the starting interval by employing the effect of the gas to preheat the burner, the gas is rst turned on and a mixture of air and gas enters, circulating through and 1l ing the air and gas chambers 63 and 65 beneath the fuel grooves. The mixture issuing from the burner orifices 73 in each groove is then. ignited by a taper or the like inserted through the tops of the combustion chambers. The mixture burns in the fuel grooves, quickly developing its full heating capacity, providing a hotblue flame which spreads throughout each fuel groove andfrapidly raises the temperature of the adjoining walls of the base to a point where the oil may be turned cn with assurance of its being vaporized as soon as it entersA the fuel space '31. The gas continues to be supplied while the oil is at rst admitted slowly. so that the oil rst entering and traveling over the bottom of the vaporizing space is c0m pletely vaporized.. the resulting oil vapor rising over the lip 27, entering into the fuel grooves, and burning in the combustion chambers with the air supplied thereto. As the burner becomes more highly heated through the joint combustion of the gas and cil, the former may be gradually cut off and the full supply of oil developed ,the burner then working exclusively under the supply of oil By this means the normally prolonged starting interval may be cut down to one of comparatively short or insignificant duration.

If' it is desired to operate the burner under gas supply alone, the full gas supply, or such part thereof as may be desired for the heat required, is turned on without the admission of oil, the gas burning with a noiseless flame in the fuel grooves and in the overhead combustion ehambers, where it is augmented by the supplemental air supply through the walls of the combustion tubes.

If, during the operation of the burner under o il, it is desired to force the burner beyond its oil heating capacity, the gas supply may be turned on at any time and, either with or without the coincident supply of oil, a name may be produced of greater volume and heating intensity than can be had from the oil supply alone.

Should any occasion arise for the switching from one type of fuel to the other, either because of the depletion or failure of the oil supply or the temporary or other failure of the necessary pressure in the gas main or other source, or for any other reason, such switch or change may be immediately made withoutalteration in the burner itself, the latter being capable of operation with gas exclusively or with oil exclusiv-ly and in the usual manner, when and as required.

It will be seen that While each fuel groove functions both as a gas burner and as a distributing space for thc oil vapor to the overhead combustion chamber, in the normal operation of the burner the oil is vaporized in the vaporizing space, the liquid oil being prevented from leaving the latter due to the raised lip 27 which is preferably carried to a height greater than that of the level permitted the oil under the action of i Vaporization .1.

ished due to the ecient preheating action of the gas burner, and such accumulations as occur may be readily removed by lifting out the inner chimney and cover plate which leaves the vaporizing space open and exposed.

While I have described the operation of the burner assuming it to be supplied with gaseous fuel, nevertheless, even where no provision is made, such as the gas supply pipe 69, for supplying gaseous fuel to the chambers 63 and 65, provided the chambers are supplied with air alone through the tube or other supply source, the disclosed burner construction has material advantages, both in reducing the starting interval and in improving the operation of the burner during its established operation after the starting interval.

With an adequate air supply to the chambers 63 and 65, air issues through the ports '73, and, as soon as the oil is vaporized in the vaporizing chamber, the oil vapor passing into the fuel spaces 29 and 31 forms a combustible mixture with the air and burns with a flame which reaches down close to the mouths of the orifices 73 at the bottom of each fuel space or groove, where it has its maximum heating effect on the walls of the base and under conditions which tend to effect the rapid heating of the base and quickly raise its temperature to an oil vaporizing point. Accordingly, it is possible to employ other methods of preheating to start initial vaporization of the oil, its initial vaporization, however, being followed immediately by the production of an intense flame at the extreme bottom of each fuel groove, filling the groove and impinging against the side walls of the base casting, this being succeeded by the rapid heating of the entire base and resulting in the reduction of the starting interval to an insignificant period of time.

Such preheating, when not effected by gas, may be carried out by means of the usual wick, or by the introduction and ignition of a more volatile liquid fuel, or by electrical means, or by any other desired heating agency either internal or external, in any case, however, the initial Vaporization of the oil being followed by the production of an intense base-heating ame due to the air supply entering through the ports in the bottom of each fuel groove.

After the burner has been brought to normal operation in the manner described, the air supply through the ports 73 may be cut off, but such air supply is preferably maintained since it is found to provide an even, smooth,'quiet fiame in the combustion chambers of more intense heat than heretofore obtainable and avoiding the roaring noise which often characterizes the use of such burners.

While I have herein described for the purpose of illustration one specific embodiment of the invention and one particular application thereof, it is to be understood that extensive deviations from and changes in the illustrated form may be made and applications-thereof other than herein illustrated may be utilized, all without departing from the spirit of the invention.

I claim:

1. A burner having a base, a perforated combustion tube enclosing a combustion chamber above the base, said base having a fuel groove beneath said combustion chamber, means communicating with said combustion chamber through said fuel groove for receiving liquid fuel to be vaporized in said base and burned in said combustion chamber, a gas chamber adjacent to and substantially coextensive with said fuel groove ducts in the Walls of said groove communicating with said gas chamber presenting gas burner orifices, and means forlsupplying gaseous fuel to said gas chamber and through said ducts also to be burned in saidcombustion chamber, said gas burner oriiices being in suicient number and arranged sufficiently uniformly around said groove to .provide a substantially uniform distribution of gas into the combustion chamber.

2. A combustion tube burner having a pair of combustion tubes forming between them a combustion chamber, a base provided with upstanding walls forming between them a fuel groove beneath and communicating with said combustion chamber, orifices in the walls of the groove for supplying air thereto, a vaporizing chamber in the base adjacent the groove and closed to the admission of air during the normal operation of the burner, and means for supplying liquid fuel to the vaporizing chamber, said vaporizing chamber having an outlet to the fuel groove above the level of said orifices.

3. A burner having a pair of perforated combustion tubes forming between them a combustion chamber, a base having an endless fuel groove beneath and opening into said combustion chamber, means for supplying liquid fuel to the base to be vaporized therein and burned in said combustion chamber, said base having a gas chamber beneath and substantially co-extensive with said fuel groove and said base being further provided with ducts formed through the walls of'said groove, communicating with said gas chamber and presenting a series of closely spaced gas supply orifices distributed throughout said groove and beneath said combustion chamber, and means for supplying gaseous fuel to said gas chamber n to be burned in said combustion chamber.

4. A burner having a pair of perforated combustion tubes forming between them a combustion chamber, a base having a fuel groove formed therein beneath and opening into said combustion chamber, means to supply liquid fuel to said base to be vaporized therein and burned in said combustion chamber, said base having a gas chamber combined therewith and adjacent to and following the contour of said fuel groove, said base having ducts presenting a series of closely spaced gas burning orifices opening from said gas chamber into said fuel groove, and means for supplying gaseous fuel to said gas chamber to be burned in said combustion chamber.

5. A burner having a pair of perforated combustion tubes forming between them a combustion ehamber a base having an annular fuel groove formed therein beneath and communicating with A said combustion chamber, means for supplying liquid fuel to the base to be vaporized therein and burned in said combustion chamber, said base having a substantially annular gas chamber combined therewith and having further, ducts presenting a series of closely spaced gas burning orices opening into said fuel groove beneath said combustion chamber and communicating with said gas chamber, and means for delivering gaseous fuel to said gas chamber to be burned in said combustion chamber.

6. A burner of the class described comprising a pair of spaced, concentric, vertically arranged, combustion tubes forming between them a combustion chamber and an inner air chamber enclosed by the inner tube, a base having upstanding walls-forming between them an endless fuel groove `beneath and communicating with said combustion chamber, said base having an opening for admitting air into said air chamber, means l l Il l l r supplying gaseous fuel to said gas chamber and.

through said ducts to be burned in said combustion chamber.

7. A burner of the class described comprising a"y pair of spaced, concentric, vertically arranged, combustion tubes forming between them a combustion chamber and an inner air chamber enclosed by the inner tube, a base having upstanding walls forming between them an endless fuel groove beneath and communicating with said combustion chamber, said base having an opening for admitting air into said air chamber, said base further having a vaporizing chamber communicating with said fuel groove and beneath said inner air chamber, means for supplying liquid fuel to said vaporizing chamber, said base having a gas chamber combined therewith and further having ducts presenting gas burning orifices opening into the burner beneath said combustion chamber communicating with said gas chamber, and means for supplying gaseous fuel to said gas chamber to pass through said orifices to be burned in said combustion chamber, said gas burner orifices being in sucient number and arranged sufficiently uniformly around said groove to provide a substantially uniform distribution of gas into the combustion chamber.

8. A burner of the class described comprising pairs of spaced, concentric, annular, vertically arranged, combustion tubes forming spaced, inner and outer combustion chambers with an intermediate air chamber` therebetween and an inner air fchamber enclosed by the inner tube, a base having upstanding walls forming between them inner and outer, spaced annular fuel grooves beneath y :and communicating one with each of said com- \bustion chambers, said base having openings for i admitting air vertically therethrough into each of said air chambers and having fuel supply ducts connecting said fuel grooves, means to supply liquid fuel to said base to be vaporized therein and burned in said combustion chambers, an annular series of ducts in each of said fuel grooves presenting gas burning orifices in sufficient number and suiciently uniformly distributed throughout said groove beneath the associated combustion chamber to provide a substantially uniform distribution of gas to said combustion chamber, and means for delivering gaseous fuel through said ducts to be burned in said combustion chambers.

9. A burner of the class described comprising pairs of spaced, concentric, annular, vertically arranged, combustion tubes forming spaced, inner and outer combustion chambers with an intermediate air chamber therebetween and an inner air chamber enclosed by the inner tube, a base having upstanding walls forming between them inner and outer, spaced, annular fuel grooves beneath and communicating one with each of said combustion chambers, said base having openings for admitting air vertically therethrough into each of said air chambers, means to supply liquid fuel to said base to be vaporized therein and burned in said combustion chambers, an annular gas chamber formed in said base beneath each fuel groove, said base having a series of ducts communicating with said gas chambers and terminating in gas burner orifices in sufficient num.- ber and sufficiently uniformly distributed beneath said combustion chambers as to provide a substantially uniform distribution of gas thereto, and means for supplying gaseous fuel to said gas chambers and through said ducts to be burned in said combustion chambers.

10. A burner of the class described comprising pairs of spaced, concentric, vertically arranged. combustion tubes forming spaced, inner and outer combustion chambers with an intermediate air chamber/therebetween and an inner air chamber enclosed by the inner tube, a base having upstanding walls forming between them inner and outer, spaced, endless fuel grooves beneath and communicating one with each of said combustion chambers, said base having openings for admitting air vertically therethrough into each of said air chambers and having fuel supply ducts connecting said fuel grooves, said base further having an open-top, vaporizing chamber communicating with said fuel grooves, a removable cover pla-te for said vaporizing chamber, means A for admitting liquid fuel from below directly to the bottom of said vaporizing chamber, said base having a gas chamber 'combined with each fuel groove and following the contour thereof, said base further having a series of ducts communicating with each gas chamber, said ducts presenting gas burning orifices beneath said combustion chambers, and means for supplying gaseous fuel to said gas chambers and through said orifices to be burned in said combustion chambers.

l1. 'A burner of the class described comprising pairs of spaced, concentric, vertically arranged, combustion tubes forming spaced, inner and outer combustion chambers with an intermediate air chamber therebetween and an inner air chamber enclosed by the vinner tube, a base having upstanding Walls forming between them inner and g outer, spaced, endless fuel grooves beneath and communicating one with each of said combustion chambers, said base having openings for admitting air vertically therethrough into each of said air chambers and having fuel supply ducts connecting said fuel grooves, said base further having an open-top, vaporizing chamber arranged concentrically within and communicating with said inner fuel groove and beneath said inner air chamber, a removable cover plate for said vaporizing chamber, means for admitting liquid fuel from below directly to the bottom of said vaporizing chamber, gas chambers formed in said base one coextensive with and beneath each fuel groove, said base having a series of ducts formed in the walls of each groove communicating with said gas chambers and terminating in gas burn-.

walls oi said groove for 'supplying air thereto below the top of said barrier, and means for supplyingliquid fuel to the vaporizing chamber whereby the iuel vapor is delivered to the groove above said air supply orifices.

`13. A combustion tube burner having a base and combustion tube means forming a combustion chamber above the base, said base comprising an annular body formed with upper and lower compartments and with avaporizing chamber, an intervening annular separating wall constituting the top of the lower compartment and the bottom oi the upper compartment, the upper compartment having spaced upright walls forming with said separating wall an open groove underlying and communicating with the combustion chamber, said lowerA compartment constituting a gas chamber underlying and substantially coextensive with said groove, said separating wail being provided with ducts presenting a number of closely spaced gas .burner oriiices substantially uniformly distributed around said'groove, said

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