US1537335A - Gas burner - Google Patents

Description

Patented May 12, 1925.

UNITED STATES PATENT OFFICE.

CHARLES N. CROSS, OF STANFORD UNIVERSITY, CALIFORNIA.

GAS BURNER.

Application led March 14, 1921.- Serial N'o. 451,989.v

operation of all gas-burners. First, if the velocity of the air-gas mixture leaving the burner ports is too great the flame is blown away from the burner and the gas cannot be efficiently utilized. Second, if the exit velocity of the mixture is too small the flame flashes back. l/Vith the larger ratios of air to gas desirable at high rates of gas consumption the range in exit velocity between fiash back and blow from ports,7 is small thus limiting the efficiency and usefulness of the burner. By decreasing the ratio of air to gas as the rate of gas consumption is decreased very low rates of gas flow in a given burner may be obtained without danger of Hash back. Then at the maximum rate of burning gas a greater ratio of air to gas is desirable to give high temperatures and consequently high eiciency of heat utilization. However, if the ratio of air to gas becomes too large the velocity of the mixture at high rates of burning reaches a value at which the flame is blown from the burner ports. Hence an object of my invention is to so vary the ratio air to gas in the mixture as the rate of gas consumption is changed so as to maintain the exit velocity between the two limiting velocities above described. IVhen such control obtains the efficiency of heat utilization is highest.

A further object of the invention is to so control the velocity of flow of the air and gas mixture as it enters the zone of inflammation as to give an unusually high flame temperature.

It has been found by experiment that to produce maximum flame temperature the velocity of the mixture as it enters the burning zone must be controlled within narrow limits, and the gas and air must be thoroughly mixed and intermingled in order to realize the highest possible flame temperatures. v

Hence another object of my invention is to provide a burner in which gas and air taken into the burner at the base are most thoroughly mixed and intermingled as they flow through the burner. l

Therefore, broadly the objects of my present invention are; to provide a gas-burner in which the velocity of the flowing mixture is so controlled as to give perfect and intense combustion at exceptionally high temperatures and to provide a gas-burner in which the ratio of air to gas may be changed simultaneously with the change in the rate of gas consumption while the burner is in operation.

In the following description of the preferred form of my invention which is illustrated in the drawings accompanying and.

forming a part of the specification, I do not limit -myself to the showing made by the said drawings and description, as I may adopt variations of the preferred form within the scope of my invention as set forth in the claims.

Figure 1 is an elevation of the burner of my invention with connections and control lever. The burner proper is shown in vertical section.

Figure 2 is a plan view of the burner shown in Fig. 1.

Figure 3 is a side view of a modified form of burner. The modification consists of a differently formed burner tube having a right angled turn near its outer end. All the other features of the burner proper are the same as in Fig. 1.

Figure 4 is a sectional view taken on the line 1M-4 of Fig. 1.

The gas burner of my invention consists of a fixed base 8 of cylindrical form adapted to be threaded tightly upon a nipple 15, Fig. 1, which is the terminal fitting on the pipe 14 through which the gas is conducted to the burner. The base is formed with a chamber' 25 into which the gas from the nipple 15 discharges. The upper wall 27 of the base is provided with openings 26 which permit the passage of gas to the orifice 18. Mounted concentrically upon the upper wall 27 and integral therewith is a conical needle 19. The upper surface of the base forms a ledge 33 which servesas: a gas tight seat for the lower end of the sleeve 7 to rest upon when in its lowest position.

Tightly screwed to the burner base is the lower end of the burner tube 5. The tube is fixedly mounted upon the base. The burner tube extends' in 'cylindrical-l above the base enclosing an intake chamber 29'the`n narrows into a throat 28 With rounded entrance and exit..= The diameter` of the' throat increases slightly in the direction of gas flow. Above the throat the tube grac'l'ua'lly flares out to the maximum diameter at the top Where a foramin'ated block 'or-"grd'G is held upon a suitably arrangediiange 32. 'Air nletjportsgi areiornied inthe wan of ythe in'talechainber; A short helical slot 22 is out through the' tube into the' intake The `throat isa veryfi'mportant feature of tlreburnefr tube. :It serves lthree offices. First, i'fariation'l in ithe `r'atio of the length if the 'parallelivalls to'fthe diameter of the throatis the mostiniportant factor in controlling Ithe velocity; of the xenteringfair and 4ga'sasth-iy approach the burningzone at l31. Second, lthe ratiotof throat length to diameter has a very marledeilect oni/the thoroughness offuthemyixing of the air' and gas before ignition vtakes' place. The mixing is performed)largelybyfthe turbulent flow of the 'gas stream.V` l,rlurbulence is .largely dep'pendvent .upon velocity tandfvis'cosity 4of the moving' fluid y a as can L be Y shoivn mathematically, l `l iir dlfy,y changing the ratioof the length the parallel Walls' 'of the throat lto its 'diameter also has avery great effecten the Aamount kof air drawn in through the 21 theinjector "effectv ofthe Vgas jet till 'pressure of 5 inches `of Water.

entering' through theorifice 18. It has I,been 'found that the maximum injector effecty is produced, so far. as it dependsupon the throat design, When the Walls of the throat divergefslightly toward the exit end of the burner... Thetotal angle ,of divergence of ab'ou'tmfoul1 xdegrees has been found to give superior results.V However, a smaller or a greater anglewmay Ybe usedY ydeprniding upon the rated' capacity of the burnenthequality of the gas and the pressure of thegas supply;v A` throat length offenen inch and a throat diameter of 5%; inchphave beenyrfound byexperi'ment to Vbe satisfactory]dimensions forja Yburner which will consume approxi- 1niatelyQO cubic feet ofga's per hour under a i L a y However I do ynot lWish to limit lmyself'itothe above throatproporti'ons as the proportions'uvary with changeof the capacity of the burner.

.s Within the end of 'the tube adjacent the baseis ai partitioned sleeve 7. Thefsleeve vmakes a close sliding fit inthe tube yet it is readily rotated about its longitudinalaxis. The. rotation serves Yto move Ithe sleeve axially by means of a pini) attached toy the sleeve and projecting through the helical slotQQ. rlhe sleeve has a transverse partition, 17., The partition has a concentrically V4located orificelS which registers Withrthe needle-19 to form a needle valve. The rotational and axial movements of the sleeve servie to change the elfective of the orifice thus vfurnishin'g 'a line lcontrol over the flow of gas entering the burner tube. The sleevevis also provided fwth air ports 20, Which can be made to register With the a'i'rVv ports 21 in the burner tube, thus effecting-*4a positive control over the amount of air drawn into the intake chamber 29 by the injector action of the gas Vjetwentering 'through ythe orifice 1g. Hencefthe Ymovementsof the', partitioned `sleeve perkfcrm'y tyyo fune-tions Simultaneeusiy d" fr thejjcorre'ct ratio.H Firstly, the` movements regulate'the gais cflw'., Sec-fondly, they regulate the" ,rate of air flew., through fs $21 ih. Prpar- 111011 te theliifef er fet pretortionality'betftv'een the, gals aicl'air rates of flov for different linl'ds'of gasA d'erent barna- Capaciues ',(aaertne alma-sions 'of al@ .thi-,oat ence esta), is iobtajind by properly vcorelating fthe slope of thev helical slot 22,' pt heleng'tli ofthe pin 19, and thefdiameter ofz'theiorilice 1118., ,Y

The preferred number yof,v airports Q3, eachin the tube and inthelsleeve. Ho'vvever another number maybe used.' a s The angle th rough which the sleevemay be rotated lshould be approximately" 80 degrees.y l,lofivever,v it `could conveniently be made anything between 60 degrees and 100 degrees. s vlljrerferably,a separate valv'eor cock` 13 of any suitabletype isfprovided inthe supply pipe 14t to shut off 'thehadmiss'ionfof to the Ylnirner base; SLU Meansgare preferably provided for c oy-o'rdin'atingt the ,operation lof :the cochand the .sleeve softhatuthe movements of the 'needle valve andtheair ports are effected simultaneously with the movements of the'cocl. .I Y c ,t A

The valve 13' is'providegd with an operating handle 12l which may be yturned to open or close therpassage into vpipe le. Projecting from the sideof the handle is `,a lever arml 11 which fixedly attached tothe handle. The opposite end ,of the lever `armis pivotally attached. link and the other end of theflink is pivoted to pin 9. Thepin 9 extends through the helical slot and` is attached to the sleeve 7,; Movement ofthe handle n12` to` open or close thexcock 13 is thus accompanied bya corresponc'ling rotational and axial movement of the vsleeve 7 which in turn opens'y or closes the needle valve orifice 18 and simultaneously ,opens and closes thelairwports 21.," Then the sleeve occupies .its extigein'e position toward the base to lclose 'the needle valve orilice thev air ports 20 are 'suflicientlyfout of registervvth the air ports 21 as to nearly close the 'area open Afor the intake yof air.'` A The fora'minated block ory gridghasfyan important influence upon' the proper functioningl of my invention. :ljoraburner of the size and' proportions shown" in F ig. l

I prefer to use a grid pierced by apertures of square section, The section can be conveniently about .07 on a side. One of the functions of the grid is to produce a large number of short blue cones of flame which give a very rapid combustion and thereby produce an extremely high flame temperature. The length of the blue cones is approximately .10 and the maximum flame temperature occurs a few hundredths: of an inch above the top of the blue cones. Because of these facts the utensil being heated can be placed very close to the top of the burner without smothering the flame. Under these conditions the flame never floats and maximum utilization of the gas is always obtained because of the high flame temperature produced.

From the above it will be clear that rotation of the sleeve 7 by movement of the pin 9 results in admitting gas under pressure through the needle valve orifice 18 into the mixing chamber 29; and also simultaneously opens the air ports 21 through which the proper amount of air is drawn into the stream of gas passing into the throat 28. From the throat the gas and air pass into the enlarged exit end of the tube where it is thoroughly mixed and the velocity reduced to the correct value which gives a series of short intensely hot blue cones of flame as the mixture emerges from the grid apertures.

In Figure 3 I have shown a modified form of burner in which the principal change is in the form of the tube 16. It is constructed with a right angled bend in the exit end giving the mixture an exit direction of flow at 90 degrees to its direction of flow at the inlet end of the burner. The cock 13 is screwed directly to the burner base and the link 24 is rigidly attached to the valve stem 23. The other end of the link is connected loosely by a slot (in the link 24;) to the pin 9, thus the movements of the handle of the valve 13 rotates the sleeve. Gtherwise the structure and operation of the burner of Fig. 3 is the same as already described in detail for the burner in Fig. 1.

I claim:

1. In a gas burner, an apertured chambered base having mounted thereon a needle, a burner tube fixedly attached to said base, a partitioned sleeve within said tube and arranged to move axially in respect to said tube when rotated, an orifice in said partition of said sleeve, and means for effecting the rotative and axial movements of said sleeve.

2. In a. gas burner, an apertured chambered base, means for supplying gas to said base, a burner tube fixedly attached to said base, a partitioned movable sleeve within the end of said tube adjacent said base, a needle mounted on said base, an orifice in said partition of said sleeve, said needle and said orifice being so adapted that the axial and rotational movements of said sleeve controls the passage of gas through said orifice and into said tube, and means for effecting the movements of said sleeve, a grid comprising a foraminated block in said tu e.

3. In a gas burner, an apertured chambered base, a needle mounted upon said base, means for supplying gas to said base, a burner tube attached to said base, air inlet ports in said tube, a partitioned movable sleeve within said tube, an orifice in partition of said sleeve, air inlet ports in said sleeve, means for operating said sleeve, and a grid comprising a foraminated block in said tube.

4. In a gas burner, an apertured chambered base, a needle formed upon said base, means for supplying gas to said base, a burner tube attached to said base, air inlet ports in said tube, a partitioned movable sleeve within said tube, an orifice in the partition of said sleeve, air ports in said sleeve, a grid arrangedl in said tube, a cock to control the flow of gas in said supply means, means for co-ordinating the operation of said cock and said sleeve.

5. In a gas burner, an apertured chambered base, means for supplying gas to said base, a burner tube immovably attached to said base, air inlet ports in end of said tube adjacent said base, a partitioned movable sleeve within said tube, air ports in said sleeve, a valve arranged in said sleeve, means for operating said valve and said air ports simultaneously, a multiported head or block on exit end of said tube.

6. In a gas burner, an apertured chambered base with needle mounted thereon, a burner tube attached to said base, air ports in said tube, a movable partitioned sleeve within said tube, air ports in said sleeve, an orifice in said partition of 'said sleeve, means to produce movement of said sleeve, a gas cock to shut off flow of gas to said base, means to coordinate movements of said gas cock and said sleeve.

In testimony whereof I affix my signature, in the presence of two witnesses.

CHARLES N. CROSS.

IVitnesses:

N. B. CHANEY, F. D. BANHAM.

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