US2685916A - Gas burner - Google Patents

Description

C. MART GAS BURNE R Aug. 1954 2 Sheet s 1 Filed Jan. 31, 1952 Ernesk C. M e 5 W6 His Avta a E. C. MARTT Aug. 10, 1954 GAS BURNER 2 Sheets-Sheet? Filed Jan. 31, 1952 Invwtov: Evnesd: C. Mar-tt,

(3 His A k kovney.

Patented Aug. 10, 1954 GAS BURNER Ernest C. Martt, Cleveland, Ohio, assignor to General Electric Company, a corporation of New York Application January 31, 1952, Serial No. 269,289

2 Claims.

This invention relates generally to gas burners and more particularly to burners suitable for the working of substances having very high fusing or softening temperatures.

The various kinds of gas burners commonly used for working vitreous substances such as glass and quartz may in general be classified into two types. The first type of burners, generally known pie-mixing burners, comprise a mixing chamber where the combustible and combustionsupporting gases are mixed and from which they are supplied to the combustion face. In order to prevent the flame from traveling back into the mixing chamber, the velocity of the mixed gases at the orifice must be greater than the speed of flame propagation through the .gas mixture. When gases such as hydrogen and oxygen are used as the combustible and combustion-supportgases for producing a very hot flame with a pre-mixing type burner, it is necessary to resort to a high velocity at the orifice. In other words, the velocity of the mixed gases at the orifice of the burner must exceed the high speed of prop- V agation of combustion in the hydrogen-oxygen mixture. When it is desired to work substances such as quartz having a softening point approaching 1500 C., the velocity of the gases issuing from the orifice of a pro-mixing type burner may be so high as to tend to warp and distort the quartz piece.

.With the second type of burners, generally known as diffusion burners, the combustible and combustion-supporting gases are led separately to the combustion face of the burner; for instance,

the gases issue in separate jets and the flame occurs as the gases mix together beyond the orifices at the burner face. In general, the difficulty with this type of burner in the working of quartz has been that of obtaining a flame evenly distributed over a desired region, instead or concentrated at one or more points depending upon the number of jets utilized.

An object of the invention is to provide a new and improved diffusion type gas burner adapted to produce a high intensity flame in a well defined region.

Another object of the invention is to provide a diffusion type gas burner producing the low velocity high intensity flame particularly suited for the working of quartz.

In accordance with the invention, the above objects are achieved by means of a burner structure which supplies the combustible and combustion-supporting gases at the combustion face in superposed ribbon-like streams. In other words, the combustible gas issues from the burner face in a number of relatively wide fiat streams and the combustion-supporting gas issues in similar streams which are interposed between'the streams of combustible gas. In the illustrated embodiment of the invention, the burner structure comprises a stack of thin plates or laminations which are alternately slotted in a manner todefine a plurality of slit-like vents in the combustion face. The slotted laminations alternate with non-slotted ones to define a plurality of parallel flat channels in the burner body through which the combustible and combustion supporting gases are conducted to the burner face. The gases are supplied to these channels through transverse passages formed by aligned holes in the laminations which lead to supply tubes in one of the end plates.

For further objects and advantages and for a better understanding of the invention, attention is now directed to the following description and accompanying drawing in which:

Fig. 1 is a pictorial View of a gas burner embodying the invention; and

Fig. 2 is a pictorialview illustrating the groupci a number of burners for the heating and softening of a work piece such'as a quartz tube.

Referring to Fig. 1, there is shown a diffusion type burner suitable for the working of substances having a very high softening point such as quartz.

In order to illustrate the internal construction,

the burner has been shown in partly exploded form; it will be realized however that in the assembled unit, the various parts are drawn vertically together. The burner comprises top and bottom frame plates I and 2 enclosing a stack of thin plates or laminations which are here disposed in four tiers A to D. Each tier constitutes a functional unit and involves in general a dupli cation of parts and corresponding plates or laminations. In order to provide rigidity to the assembly, the tiers are separated from each other by somewhat thicker spacer plates 3, i, and 5.

Within tier A, there are three slotted laminations 6, I, and 8 which alternate with non-slotted laminations 9 and Hi serving as spacers. Laminations 6 and 8 are provided with an L-shaped slot ll which originates at a drill hole [2 and terminates in a narrower tongue-like portion at edge i3. When the laminations are assembled into a stack, the edges I3 define the combustion face of the burner. Top plate i and spacer plate 9 cooperate with lamination t to define a fiat channel corresponding to slot H, which channel terminates at the combustion face in a slit-like vent Hi. In similar fashion, lamination IE3 and spacer plate 3 cooperate with slotted lamination 8 to define a vent E5. The holes l2 drilled in cooperative alignment in all the plates or laminations define a passage in the burner body to which a combustible gas such as hydrogen is supplied through a tube It fitted in hole 12 within top frame plate I.

Lamination 1 is provided with a straight slot ll running directly from a drill hole Hi to the combustion edge [3. In cooperation with the intermediate spacer laminations 9 and Iii, slot I! defines a flat channel through which a combustionsupporting gas such as oxygen is supplied in a flat stream to the combustion face of the burner. The laminations intervening between lamination 1 and top plate I, that is laminations 6 and 9, are drilled at It to form a passage for supplying oxygen to vent Hi through a tube 20 which is fitted into hole IS in the top plate. It will be observed that passage !8 ceases or terminates at lamination I and is not carried through any plate or lamination below it. Thus tube 2Q communicates exclusively with vent l9 and with no other.

The arrangement of slotted laminations alternating with non-slotted spacers in tier A thus provide for the issuance of a ribbon-like stream of oxygen at vent l9, which is interposed between similar streams of hydrogen issuing from vents i i and E5.

In tier B, the laminations are disposed according to a pattern or cycle generally similar to that of tier A, with the difference that lamination ii is provided with a longer slot 22 which originates at a drill hole 23 lying further back than drill hole 58 in lamination 5. Drill hole 23 is carried through all the laminaticns intervening between lamination 2i and the top plate i so as to define a passage for the separate control of oxygen supplied to vent 21% through tube 25 in plate l.

Tier A and also the upper portion of tier B have been illustrated in exploded form, whereas the lower portion of tier B and also tiers C and D have been illustrated as they are when actually assembled. Tiers C and D follow the same general pattern as has been described, the intermediate oxygen slot in tier reaching back to drill holes or passage 28, and that in tier D reaching back to passage 21'. These passages are likewise carried through the intervening laminations to allow for the individual control of the oxygen supply from tubes 2% and 29 to their respective vents in the burner face. The hydrogen supply is common to all the tiers through passage i2 and tube it.

It will be observed that each tier contains an intermediate oxygen vent, for instance vent [9 in tier A, and two hydrogen vents, one above and the other below the oxygen vent, as vents i4 and I5. The burner is thus adapted to produce a reducing flame, that is one containing an excess of hydrogen which burns in the ambient air. This arrangement has been found most suitable for the working of quartz tubing, but it may evidently be varied to suit the needs of the application, and a neutral or an oxidizing flame may be obtained by suitable changes in the number and in the grouping of oxygen and hydrogen supplying vents.

It will be appreciated that by following the -pattern of stacking which has been described, the present burner structure may be expanded to include any desired number of tiers. Where separate control of the combustion-supporting gas (oxygen) supply is required for each tier, the oxygen lamination in each tier is provided with a slot reaching back to a drill hole which is carried up through the intervening laminationsv to the top plate and to its individual supply tube. The stack. of laniinations may be held together by suitable means such as clamps, or if desired through drawbolts as shown at Eli and reaching through the whole stack and cooperating nuts shown at 3 l.

Referring to Fig. 2, there is shown a grouping of four burners 32 to 35 each similar to the burner illustrated in Fig. 1. The compact construction of the burner permits locating the burner faces H3 in a tight circle about the work piece. The work piece is illustrated here as a length of quartz tubing 35 which is required to be softened for the sealing of molybdenum leads into its ends by collapsing or pinching the walls together on the leads. The combustible and combustion-supportinggases issue from the burner face in interspersea streams so that the diffusion of the gases occurs very rapidly and a concentrated flame of high intensity occurs immediately in front of the burner face. The flame is evenly distributed because the gases issue in closely spaced ribbonlilre streams and does not tend to form concentrated hot spots as with prior art diifusion burners. Moreover, since the gases are not premixed, they are allowed to issue at the vents with relatively low velocity, and distortion or warping of the quartz tube is thereby avoided. The separate control of the oxygen supply to each tier in the burners permits accurate adjustment of the intensity of the flame along the height of the tube.

It will be understood that the specific example of a burner embodying the invention which has been shown and described is to be considered as illustrative only. The sizes and proportion of parts may readily be varied in order to adapt the burner to a particular function, and it will of course be obvious that the stacking arrangement or repetition of laminations may be expanded to provide a burner of any desired size. The scope of the invention is accordingly to be determined the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A gas burner comprising a stack of laminations having tongue-like portions with a front edge forming a combustion face, spaced laminations within said stack having slots terminating at said edge, the slotted laminations cooperating with intermediate non-slotted ones to define a plurality of parallel fiat channels ending at said face in slit-like vents, the slots in selected ones of said laminations being extended progressively further back from said face and the laminations intervening between a particular slotted lamination and one side of said stack having holes located in cooperative alignment with the end of the slot in that particular lamination for defining a transverse passage through the stack communicating with the channel in that particular lamination.

2. A gas burner comprising a stack of laminations having an edge forming a burner face, means including top and bottom frame plates holding said stack together, spaced laminations within said stack having slots, terminating at said edge, the slotted laminations alternating with non-slotted ones to define a plurality of parallel flat channels ending at said face in slitlike vents, the slots in selected ones of said laminaticns being extended progressively further back from said face, the laminations intervening between a particular slotted lamination and one of said frame plates having holes therein in alignment with the end of the slot in that particular lamination for defining a transverse passage communicating with the channel in that lamination, and tubes fastened through said one frame plate and communicating with said transverse passages for supplying gas at separately controllable rates to the various vents.

iteferenees Cited in the file of this patent UNITED STATES PATENTS Name Number Date

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