US2349323A - Burner - Google Patents

Description

May 23, l944 J. A. WHITTINGTN v2,349,323

BURNER Filed April 8, 1940 d T C type.

Patented May 23, 1944 UNITED STATES PATENT OFFICE BURNER James A. Whittington, Evanston, lll.

' Application April `8, 1940, Serial No. 328,413

- 1 Claim.

The present invention relates in general to burners and is particularly concerned with an im` proved gas burner of the type generally known as a Bunsen burner.

Heretofore, burners of this type were of such design and operated in such manner that the burners had to be constructed of diiiere'nt sizes and dimensions for each type of gas with` which the burner was to be utilized. v'I'hat is, if aburner, for example, were to be utilized for'the burning of a gas having a comparatively high B. t; u. content such as iso-butane, the burner in order to operate efficiently had to have its parts relatively so proportioned ras to size as to provide the proper mixture for this particular gas, whereas for a gas such as the so-called mixed gas hav-Y ing a relatively low B. t. u. content a different size burner with parts of different sizes and proportions was necessary. Due to the difference in sizes in the burners required for the different gases with which the burners might be utilized; it was heretofore necessary for the burner manu# facturer to build or the burner supplier to provide y a plurality of burners of different sizes,` thus materially increasing the cost of manufacture and the cost of stocking the burners.

The present invention broadly contemplates an improved burner of such construction and design that the size of the burner may be standardized irrespective of the particular gas utilized in the burner. To this end, in 'my improved burner, the mixing chambers and air inlet openings are standardized as to their relative proportions and may be used without change for all the gases commonly available for burners of this The size of the gas inlet orice is the only part which is varied in my burner to adapt it for use with a particular one of the available gases.

'I'his construction is of tremendous advantage from the standpoint of the cost of manufacture and inthe maintenance of burner stocks. The burner may be initially fabricated, without a gas orifice, as a simple standardized stock item or unit available for use with any of the usual gases. All that is then vnecessary to commission the burner for use with a particular gas is to provide the stock unit with an orifice of proper predetermined size depending upon the particular gas With which the burner is to be utilized. Since this orifice is in the form of a round passage, it will require but one simple operation to commission the'burner for use with any one'of the gases, and this commissioning operation may be simply accomplished by means of a proper size drill.

, Moreover, a burner embodying the features of G5 construction of my invention having a standard size and overall dimension for utilization with thedifferentgases is further advantageous in that `it may be most eiciently utilized inboilers, refrigerators, and other commercial and industrial! applications. For example, sucha burner enables the use of a standard mounting to provide the most eilicient spacing between 'the burner tip and the surfaceof the body being heated, thus making it unnecessary to vvary this distance for diiferent'installation conditions wherein different gases may respectively be utilized.

VIt Yis a`further object of the herein described invention to provide an improved burner construction which will operate with extremely high efficiency; which will be free from back-iire, carbonization and other undesirable operating characteristics; and in which the various parts of the burner.1are relatively so proportioned in such novel manner as to maintain a practically constant air-'gasratio during variation of thegas pressure over a wide range, a feature which was "heretofore thought could only be attained in a burner with aVenturi type of mixer.

,It is a further object of the present invention to provide an improved burner construction adjacent the eiiluX end of the gas admitting orifice for the collection of dirt, lint and other foreign matter to keep it from occluding the orifice, particularly under operating conditions in which the gas may be admitted at a comparatively low pressure. I i A further object of the invention is to provide an improved construction at the combustion end of the burner tip for facilitating'the successive lighting off of a plurality of adjacently disposed burners from each other after one of the burners has been lighted.

A still further object of the invention is to provide an improved method of making or constructing a gas burner.

Still another object is "to provide an improved method of burning various gases in a single burner of the herein described type.

Other objects and features` of the invention will more fully appear from the following detailed description taken in connection with the accompanying drawing, which illustrates a single embodiment thereof, and in which:

Figure 1 is a vertical longitudinal sectional view through a burner constructed in accordance with the features of the herein described invention;

Figure 2 is-a plan view of the same; v

Figurey 3y is a1 fragmentary view in elevation looking toward the air inlet opening of the burner;

Figure 4- is a transverse sectional view taken through the burner at the position of the air inlet opening, taken substantially on line IV-IV of Figure 1;

Figure is a fragmentary sectional view showing an alternative construction at the efux end of the burner gas orice; and

Figure 6 is a fragmentary sectional view showing an alternative construction at the combustion end of the burner.

As shown on the drawing:

As illustrative of the burner of my present in vention, I have selected a construction as shown in detail on the drawing, this construction embodying the features of operation and utilization as will hereinafter be disclosedin detail.

In general, the burner of the present invention embodies an elongate tubular body as generally indicated at I0 which maybe constructed of any suitable material such as brass, bronze and vthe like. The lowermost end of the burner body is tapered and threaded as shown at II to enable connection of this end to a suitable gas supply for the burner. The opposite end is in the form of a contracted tubular portion I2 which is preferably integrally formed with the body of the burner. Intermediate the ends of the burner, the body is preferably formed with a polygonal outer surface for receiving a suitable wrench or tool., whereby the burner may be rotated during its connection to a suitable base or other supporting structure through which gas may be supplied to the burner.

Anelongate tubular sleeve I3 isdisposed with its lowermost end margin surrounding the tubular extension I2, the lowermost end of the sleeve being in abutting relation with a peripherally extending abutment shoulder I4 at the lowermost end of the extension I 2 where the extension joins the burner body. The sleeve I3, it will be noted,

chamber I'I at its uppermost end communicates with a second stage expanding or mixing chamber I8 which is in axial alignment with the rst stage chamber.

It will be noted that the juncture of the rst and second stage chambers is connected by an abrupt shoulder or surface I9 which acts to set up eddy currents or a certain amount of turbulence as the combustible mixture passes from the rst stage chamber to the second stage chamber, thus materially enhancing the mixing of gas and air before it reaches the opening I5 at the uppermost end of the sleeve I3.

The lowermost end of the burner body is provided with a central bore or passage 20 for gas which leads to a gas orice or nozzle 2| of tubular form and predetermined cross-sectional area, as will later-be described in detail.

Thev gas eillux end of the nozzle is centrally disposed at the lowermost end of the chamber II.

In order to supply air or other-supporter' of combustion to the gas issuing from the orifice 2 I', the body of the burner is provided with a laterally cut slot 22 which extends into the lower end of the chamber I1 and is adjacent to or proximate to the discharge end of the gas orice. The bottom surface or oor 23 of this slot is preferably even or level with the discharge end of the orice as shown.

While the foregoing describes in a general manner, the construction of my improved burner, it has been found that in order to successfully operate the burner and e'iciently 'burn the combustible mixture of gas and air and prevent backfring of the burner, the air inlet, mixing chambers and the gas orifice must be proportionedas to length, size, etc. in a very denite relationship.

In determining the relationship and-proportions between the various parts of my improved burner, the combustion constants of the various gases have been taken into consideration and are listed in the following Table A:

TABLE A Air Lbs. of Theo- Gas B t u Cu. ft. gas Lbs. gas lf'gg'gg air retcal Std. Area pressure, Gas Sp. gr. per 'c 'it required] required] bastion required area of d rill ol inches B.t.u. 2 B.t.n. pounds per per 3200 orifice size orice water pound gas B.t.u.

Methane 0. 5543 1, 014. 7 3. 153 0. 13378 17. 274 2. 3109 001096 001 3, 1 Ethane. l. 0488 1, 781. 0 1. 797 0. 14428 16. 132 2. 3278 .000624 70/. 00062 5.8 Propane. 1. 5617 2. 572.0 1. 240 0. 14834 15. 712 2. 3307 .000431 74/. 00040 8. 7 Iso-bu tane. 2. 0665 3, 251.0 0. 9843 0. 15672 15. 495 2. 4283 000342 75/. 00035 1l. 5 N-butane.. 2. 0G65 3, 353. 0 0. 9544 0. 15099 15. 495 2.3396 000342 00035 11. 5 N-pentane 2. 4872 3, 981.0 0. 8038 0. 15304 15.366 2. 3516 000279 77/. 00025 13.8 N-hexane 2. 9704 4, 667. 0 0. 6857 0. 15593 15. 275 2. 3818 000238 77/. 00025 16. 5 Ethylene. 0. 9740 1, 631.0 1. 9620 0. 14829 14.820 2. 1977 000682 69/. 00070 5. 4 Propylene. 1. 4504 2, 336. 0 1. 3656 O. 15158 14. 820 2. 2464 000475 73]. 00045 8. 1 Butylene 1. 9336 3, 135.0 1. 0207 0. 15106 14.820 2. 2387 000355 75/. 00035 10. 7 Acetylene 0. 9107 1, 503.0 2. 1290 0. 14841 13. 306 l. 9736 000740 69/. 00070 5. 1 Benzene. 2. 6920 3, 741.0 0. 8554 0. 17621 13. 306 2. 3247 000297 76/. 00031 15.0 Toluene. 3. 1760 4, 408. 0 0. 7259 0. 17646 13. 535 2. 3884 .000252 77/. 00025 17. 7 Mixed. 0. 540 800 4.000 0. 16535 13. 785 2. 2793 .00139 58/. 00139 3.0 NaturaL. 0. 675 1, 039 3. 0. 16018 14. 631 2. 3392 00107 63/. 00108 3. 0

extends an appreciable distance beyond the outermost end of the extension I2 to define an outlet I5 at the uppermost end of the sleeve. The uppermost end of the sleeve I3 is preferably provided with a chamfer I 6 or similar bevel to aid in the inflow of air to the burner flame for supporting combustion thereof at the opening I5,

In the construction shown, the body IIJ of the burner and the extension I2 cooperate to dene an elongate tubular passage or bore I1 which constitutes a first stage chamber for the mixing of air and gas admitted to the burner.'

The

It is generally well known that the Weight of air required to liberate a B. t. u. from a gas is, for all practical purposes, substantially constant for the different gases, and, that as between gases having different B. t. u. contents the amount of air required for combustion will be proportional to the B. t. u. contents of the respective gases.

By reference to Table A, column 5, it will be noted that the Weight of gas for a given B. t. u. content is substantially constant. With a knowledgev of the foregoing relationships, it can be shown that theweight 'of air required for the combustion of Vquantities of the various gases sufcient to liberate a desired or given heat value is substantially constant.' This constancy is shown in Table A, column 7.

The commercial gases available for use with burners of the herein described type are usually composed of the combustible gases listed in Table A, either singly or in various proportions, together with inert gases such as carbon dioxide and nitrogen, and a small amount of oxygen. Since the weight of air required to liberate a given heat value from the various gases is substantially constant, as previously pointed out, it therefore follows that the weight of air required for mixtures of these various gases to liberate the given heat value, will remain substantially the same as for that of only one of the gases.

It will therefore be apparent that with these substantially constant factors in the various gases, if 'the air inlet opening to the burner is made of such size as to be capable of Vadmitting the required amount of air for combustion, the size of this opening may be made constant and of fixed value irrespective of the gas which is being utilized, provided the gas orice and gas pressures at the manifold are properly determined. Since the rate of admission or injection of the air into the gas is known to be a function of the gas momentum as it issues from the gas orifice, it is therefore possible to provide an orifice of proper size to admit the required amount of gas to liberate whatever B. t. u. per hour'heating effect may be desired, for example, 3200 B. t. u, per hour, and that by utilizing the proper gas entering pressure, the momentum of the gas stream may be maintained substantially constant.

When the proper size orifice and gas pressure are determined, no other change in the burner design is necessary for satisfactory operation with a particular gas. It will therefore be apparent that with a burner of proper design, the mixing chambers and the air inlet opening may be constant factors in the burner, and the only variable in the burner construction is the size of the gas orice.

By way of a specic example, a burner designed to liberate 3200 B. t. u. per hour when a gas is burned therein, will have the dimensions as indicated in the following Table B:

TABLE B Burner parts Dimension In general, it will be noted that with the above dimensions the cross-sectional areas of the first stage chamber and the second stage chamber will be in the ratio of substantially one to two, that the first and second stage chambers are of sub- 'stantially the same length and that the air inlet interior circumference of the rst stage mixing.

the slot'will therefore extend a substantial 'distance past. the eiiiux end of the gas orifice.

Since the dimensions of the burner as given in Table B are of constant determination irrespective ofthe gas with which the burner is to be used, the burnerwill :have constant overall dimensions; The burner may therefore be constructed as a standard unit or stock item, without an orifice therein, and may subsequently be commissionedat any time desired for use with a particular gassimply by drilling the proper size orice; as shown in Table A, column 9. Column l0 shows the proper gas pressure to be used in each case with the burner for the particular gas for which the burner has been commissioned, regulating means being provided usually at the place of installation so that the gas pressure may be regulated to the desired value.

For example, if it is desired to burn 3200 B. t. u. per hour of 800 B vt. u. mixed gas, the burner would have an orifice with a cross-sectional area of ..00138sq; inch, such as would be produced by a standard No. 58 drill, and the proper gas pressure to utilize at the manifold would be 3 inches water column. AAs initially constructed, the bore 20 is closed by a partition relativeto the first stage mixing chamber. Thus, when it is desired to commission the burner for a particular gas,` all that is necessary is to drill an opening of proper size through this partition to form a gas orifice interconnecting the bore 20 with the rst mixing chamber.

Since the amount of air inspirated into the gas is dependent' upon the momentum of the gas leaving the orifice, the air-gas ratio remains substantially constant for the various gases with changes in their pressure.

In the following Table C, I have shown the air-gas ratio for a burner of the present invention when utilized with an 800 B. t. u. mixed gas:

TABLE C Air-gas ratios [800 B. t. u. mixed gas] Psffse Gas Per cent Air-gas Per cent water rate gas ratio air It will be noted from the above table that the gas pressure may be varied over a wide range without materially affecting the air-gas ratio. A very eicient burner therefore results in which complete combustion will take place, and backring, blowing from the ports, and other undesirable operating characteristics will be eliminated.

Referring to Figure 5 of the drawing, I have disclosed an alternative construction at the efux end of the burner gas orifice. In this construction instead of making the floor 23 of the air admitting slot even or level with the discharge end of the orifice as shown in Figure 1, the portion of the floor lying within and adjacently surrounding the orifice is provided with an annular groove or recess 24. This groove or recess forms a downwardly extending extension of the first stage chamber and does` not-interfere Withthe eflicient operation of the burner, the outlet end of the orifice being retained as before at the floor level of the air inlet slot. This alternative construction is particularly advantageous, When-the burner is utilized with low gas entrance pressures, as 'it prevents the accumulation of dirt, lint and other foreign matter at the orifice, which might otherwise occlude the orifice and aiect its proper functioning. This construction is especially desirable. when the burner is to be utilized as a pilot light.

In Figure 6, of the drawing, I have shown an alternative construction in which the uppermost end of the sleeve I3 instead of beingprovided with an outside chamfer I6 is provided With` an inside chamfer as shown at 25. This arrangement gives a slight flare to the burning flame and is especially advantageous in that it facilitates the successive lighting off of a plurality of adjacently mounted burners one from the other, after one of the burners has been lighted.

While in the disclosed burner construction, I have shown the first and second stage mixing chambers as being formed of separate parts, it will be readily` appreciated that the extension l2 and'sleeve I3 may, if desired, be integrally formed of one piece.

liti is thought that the. improved method of constructing a burner of this type, as Well as the improved method of burning a gas in such burner will be readily apparent' from the foregoing description of my improved burner.

lF'rorn thev foregoing description, it will be apparent that the present invention provides an improved burner of the Bunsen type which may be initially provided as a standard unit with xed dimensions; which may be readily commissionedfor use with any one ofl a plurality of different gases merely by providing a proper sized orifice as determined by the particular gas for which the burner is to be utilized; which Will operate with high efficiency, is free from backfire, carbonization, and other undesirable operating characteristics; a burner in Which the various parts thereof are relatively so proportioned as to main tain a practically constant air-gas ratio during variations in gas pressure over a Wide range; which is so arranged as to facilitate the successive lighting off of a plurality of adjacently mounted burners, when one of the burners has been lighted; which utilizes a novel construction in which occluding of the burner gas orifice by foreign matter is effectively prevented, especially at low gas pressures; which embodies an improved method of making a gas burner; and which utilizes an improved method for burning of the gas.

It is of course to be understood that although I have described in detail a preferred embodiment of my invention, the invention is not to be thus limited, but only insofar as defined by the scope and spirit of the appended claim.

I claim as my invention:

A burner comprising a body member having an elongate passage open at one end and a gas orifice at the other end thereof, and an air ad.- mitting slot in said body at the junction of said orifice and passage extending partially through the body from one side thereof With its inner end terminating between the longitudinal axis of the body and the opposite side thereof.

JAMES A. NHITTINGTON.

Images