US2499218A - Gas burner of the type in which combustion is accomplished in a refractory lined combustion chamber - Google Patents

Description

8 1 2, 9 9 4.., 2 s I N o I T wv. um wrm CBG HA 4 Cmmo.. I 1 smmc S N6 Hxmmt. .E O rDm- .NMOS F Cd I e mh 1 D.. .1 um? @I CL A Feb. 28, 1950 GAS BURNER OF n wr@ Emma@ 1N VEN TOR. 6M@ a /w gmw" @07 7017/145 Y Patented Feb. 28, 1950 ons mmm or' mTYPEINWRICH LDIIBUSTION IS ACCOMPLISHED IN source of supply through conduits i6 and I6 oonnected to the inlets oi' the chambers. In the conduits I6 and I6 are connected manually operable valves l1 and I8, respectively, for individually controlling the pressure and rate at which the A BEFBACTCBY LINE!) CGMBUSTION HAMBEB Frederic 0. Beal. Philadelphia, Pa., asllgnor to Sein (iorporation oi' America, Philadelphia, Pa., a corporation o! Pennsylvania Application September 26, 1946, Serial No. 699,415

l 2 Claims. (CL 158-105) 2 This invention relates to burners of the type combustible gas mixture is supplied to the chamhaving a refractory lined combustion chamber in bers l2 and I4. which practically complete combustion of a com- One end oi a hollow open-ended metallic shell bustible gaseous mixture is accomplished and i! is removably secured at 26 to the base memirom which heated products of combustion are 5 ber Il. The shell I6 envelops and snugly holds discharged at a. relatively high velocity through in position a hollow refractory body 2l having a restricted outlet in the form of a high tema partition 22 which divides the interior thereof perature gas stream. into two combustion chambers 22 and 26 extend- It ls an object of the invention to provide an ing alongside each other. As shown, the hollow improvement in burners of this type. particul refractory body 2| comprises a number of refraclarly to obtain better distribution of the high temtory parts formed of any suitable material. such perature heating gases produced by the burner. as silicon carbide or beryllium oxide, which are I accomplish this by providing a hollow partiunited together in any suitable manner, as by tioned body to form two combustion chambers a high temperature air-hardenable cement, for whose restricted outlets are closely adjacent to i example. In order that the refractory body 2l one another so that work during its movement will be rigidly held within the shell I9. a layer past the outlets at close range thereto is iirst 26 of air-hardenable cement may be applied to heated by one high temperature gas stream and the'exterior surface of the refractory body bei'ore immediately thereafter is heated by the other the latter is positionedinthe shell. high temperature gas stream. The combustible gas mixture delivered to the Further. the combustible gaseous mixture is inlet chambers or manifolds I2 and Il liows supplied to the inlets of the combustion chambers therefrom through apertured screen members 26 from separate hollow manifolds to each oi' which and 2l which may be formed of beryllium oxide, the gaseous mixture may be independently supi'or example, and positioned at the inlet ends of plied at a controlled rate and pressure. By inthe combustion chambers 23 and 24. In this way dependently controlling the supply of combustible the combustible gaseous mixture is subdivided gaseous mixture toeach combustion chamber, the into a multiplicity of small jets. In burners of character and physical properties of the high ternthe general type being described, practically perature gas streams may be individually regucomplete combustion of the gas jets may be aclated whereby each gas stream will precisely ef- 30 complished in the combustion chambers 23 and feet the desired heating of the work during its 24, as will be described presently, and the high movement past the outlets. temperature gases produced therein and consist- The above and other objects and advantages ing substantially entirely of heated products of of the invention will be more fully understood combustion, are discharged through restricted upon reference to the following description and outlets 28 and 29 as high temperature gas streams. accompanying drawing forming a part oi this When the burner I0 is relatively cool and at a specification, and of which: low temperature, it is placed in operation by ini- Fig. 1 is a vertical sectional view, taken at line tially supplying combustible gaseous mixture I-l of Fig. 2, of a burner embodying the inventhrough the conduits I5 and I6 at a relatively low tion; pressure which may be equivalent to a, pressure Fig. 2 is a sectional viewl taken at line 2 2 of corresponding to about 5 or 6 inches of water Fig. l, to illustrate the burner more clearly; and column. for example, so that the gaseous mix- Fig. 3 is an end view looking toward the reture discharged from the combustion chambers Y stricted outlets of the burner illustrated in Fig. l. 23 and 2l can be ignited to Produce and main- Refell'ing t0 the drawing. the gas burner I6 45 tainilames at the outlets 28 and 29. embodying the invention includes a. hollow metal- When he llames are being maintained at the lic base member l I formed to provide two chamoutlets 26 and 26, the pressure of the gaseous mixbers l2 and I4. The chambers I2 and I4 serve ture supplied through the conduits IB and i6 as inlet manifolds for a combustible gaseous mlxmay be momentarily reduced suiilciently to cause ture which is delivered thereto from a suitable the flames to backiire through the outlets 28 and 26 onto the apertured screen members 2B and 21 in the combustion chambers 23 and 2l. When this occurs a plurality of llames are produced and maintained at the upper ends of the small aper- 66 ture formed in the screen members 26 and 21.

When the names are being maintained within the combustion chambers I8 and 14 at the top suriacesoi' the apertured-screen members 2l and I1. the pressure oi the us mixture supplied through the conduits Il and-ii maythen be increased. Aiter a short interval of time the names maintained at the top surfaces ot the screen members It and 21 edect such heating of lthe inner refractory linings that these surfaces are heated to high incandescent temperatures. The heating of the inner refractory linings to a highly incandescent condition and radiant heat therefrom promotes substantially complete combustion oi the gaseous mixture in the combustion spaces 23 and Il before the mixture reaches the outlets 2l and 2|. From the outlets 28 and Il are discharged gas streams at temperatures nearly equal to the temperatures in the combustion spaces 23 and 2l.

By way of example and without limitation, the heated products of combustion may be discharged from the combustion spaces 23 andV 2l through the restricted outlets 2l and 29 at elevated temperatures over a wide temperature range up to 2900 F. and higher, when a combustible gaseous mixture of air and ordinary gas, such as city gas havinga B. t. u. rating of about 550 B. t. u. per cubic foot. for example, is supplied at a delivery pressure in the neighborhood oi.' three pounds per square inch. Under such operating conditions the pressure in the combustion chambers 2t and 24 may vary over a wide range up to a pressure corresponding to 'I0 inches oi water column and a'ppreclably above that of atmospheric pressure. The heated gases may be discharged from the burner It through the outlets 2B and I9 over a wide velocity range up to a maximum velocity of 1000 feet or more per second.

In certain heating applications heating of work entirely by a single gas stream does not utilize the high temperature gases emciently. This is particularly true when work oi elongated extent is moved continuously into the gas stream at close range to the restricted outlet to be heated from the ambient temperature to a desired elevated temperature. In such cases the portion oi the gas stream into which the work initially passes is in a sense acting to preheat the work. When heating of the work is accomplished by a single gas stream, all of the high temperature gases forming the gas stream are at the same high temperature and high velocity and at optimum values determined by the maximum temperature to which the work must be heated. While a portion of such gas stream can be employed to effect preheating of the work, experience has shown that such high temperature gases into which the work initially passes are not eillciently utilized.

Thus, in certain heating applications it is not necessary for the high temperature gases, in the portion of the gas stream into which the work initially passes, to be discharged from the burner outlet at the same high velocity as the gases in the portion of the gas stream into which the work ilnally passes to be heated to the desired elevated temperature. In many instances the work is heated more eillciently in its initial stage by discharging the heated gases against the work at a reduced velocity and at a reduced temperature.

One example o! such heating is that of heating glass filaments or rods which are continuously i'ed into the high temperature gas streams for producing glass ilbers. The portion o! the gas stream into which the glass illaments are initially ted is desirably such that successive longitudinal portions o! the rods or illaments are heated to a temperature just short of the fusing temperature without any danger of distorting or otherwise adversely aii'ecting the rod or filament by the lvelocity at which the gas stream impinges the work. After such preheating of the glass iliament or rod, it is then made ready to be heated to its fusing temperature by the portion of the gas stream at the maximum velocity and maximum temperature tor the most emcient production oi glass bers.

The burner Il of the invention is especially suitable for the production o! glass ilbers from rods or tllaxnents as well as other heating applications where precise control o! the heating of work is necessary and desirable in the initial and final heating stages. By providing the burner it having two combustion chambers I8 and Il alongside oi each other. and independently controlling the supply oi' combustible gaseous mixture to each chamber. the temperature and velocity at which the gas streams are discharged from the outlets 28 and 2l can be accurately controlled. In this way, when work or elongated extent is fed at close range to the outlets 28 and Il, as indicated in dotted lines at Il in Fig. 2. the temperature and physical properties oi each gas stream can be independently regulated to eect the desired initial heating by the gas stream dis-l charged irom the outlet I! into which the work initially passes; and the nal heating by the gal stream discharged from the outlet It into which the work immediately passes from the iirst gas stream.

In the embodiment of the invention illustrated. the outlet 2B is more restricted than the outlet Il. Hence, by supplying the combustible gas mixture to the chamber 2l at a pressure less than that at which the gas mixture is supplied to the combustion chamber 2l, the heating gases will be discharged irom the combustion chamber 24 at a lower temperature and at a lower velocity than the heating gases discharged from the combustion chamber 23. This regulation of the temperature and velocity at which the heating gases are discharged from the outlets 2l and Il can be positively controlled by independent adjustment of the valves I1 and il.

It will now be understood that an improvement has been provided in which etllcient distribution of the high temperature heating gases produced and developed in a single burner is obtained. In the illustrated embodiment ot the invention, the outlets 28 and 29 are relatively close together whereby the gas streams discharged therefrom brush against each other and in effect form a single large gas stream. In this way, the work, after it once passes into the gas stream, will always be enveloped in an atmosphere of the heating gases during its movement past both of the outlets 2l and I8.

While a particular embodiment of the imy chambers at the inlet ends thereof, means to control individually the supply o! a combustible mixture to each manifold whereby a combustible gaseous mixture maybe independently supplied thereto at a controlled rate and pressure. means forming the inlets of the chambers providing a number of small passages for subdividing into a plurality of iets the gaseous mixture entering the chambers from the manifolds, the outlets and inner wall surfaces of the chambers being formed entirely of high temperature refractory material whereby substantially complete combustion of the ,iets may be effected in the chambers, and the outlets being disposed closely ad- ,iacent to one another so that the heated gases discharged from the chambers in the form of high temperature gas streams may be applied to work at close range to the outlets in such a manner that the work during its movement past the outlets will be lmpinged by the gas streams in succession.

1A burner comprising structure providing two hollow bodies disposed alongside one another whlch form two combustion chambers having inlets at one end and restricted outlets at the opposite end, means providing two hollow manifolds each of which is in communication with a different one of the chambers at the inlet end thereof, means to control individually the supply of a combustible mixture to each mani- 3o fold whereby a combustible gaseous mixture may be independently supplied thereto forming a controlled rate and pressure. means at the inlets of thc chambers providing a number o! small passages for subdividlng into a plurality Vof ,iets the gaseous mixture entering the chambers from the manifolds. the outlets and inner wall surfaces of the chambers being formed en- 4tirely of high temperature refractory material whereby substantially complete combustion of the iets may be eil'ected in the chambers, and the outlets being disposed closely adjacent to one another so that the heated gases discharged from the chambers in the form of high temperaturc gas streams may be applied to work at close range to the outlets in such a manner that work during its movement past the outlets will be impinged by the gas streams in succession.

FREDERIC O. HESS.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,782,683 Giacomino Nov. 25, 1930 2,367,119 Hess Jan. 9, 1945 FOREIGN PATENTS Number Country Date 498,295 Germany May 21, 1930

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