US1146724A - Method of burning explosive gaseous mixtures. - Google Patents

Description

C. E. LUCKE.

METHOD OF BURNING EXPLOSIVE GASEOUS MIXTURES.

APPLICATION FILED SEPT-21.1912.

Id; 9 l %fi% Patented July 13, 1915.

A ttest: m I ntor: 4. i

To all whom it may concern:

CHARLES E. Lucxn, or NEW Yonx, N..Y., ASSIGNOR 'ro GAS AND on. COMBUSTION COMPANY, or NEW YoRK, N. Y., A CORPOBATION. or DELAWARE' I METHOD OFIBURNING ExrLosIvE eAsEoUs mrxrunn's.

maaaea.

. Be it known that I, CHARLES E. LUGKE, a

citizen of the United States, residing at New'York city, in the county ofNew York and State of New York, have invented certain new. and useful Improvements in Methods of Burning Explosive Gaseous Mixtures, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.-

This invention relates to a method of burning explosive gaseous mixtures continuously or non-explosively as distinguished dustrial value because of its great e'fliciency due to the minimum amount and Weight of products of combustion per unitfof heat de veloped, and becauseof the high temperature attained. V

The object of the present invention is genorally to develop the possibilities of continuous combustion of such explosive mixtures in certain directions beyond what has heretofore been accomplished, and -to do this in such a Wayv as to give great range of control I and adaptability, with freedom from liability of the combustion communicating back to the source of supply of the mixture.

vF or the continuous and localized combusr 'tion of explosive gaseous mixtures-two conditions must be realized;first, preventionof back flash, or communication of flame.

through the advancing mixture toward the source of supply; and, second, prevention of blow-ofl, or the carrying away. of :the

- flame and dissipating:ordilution of-the' mixture in'space,-which will usually occur when the velocity of the'mixture at the surface or zone Where the combustion is wantedexceedsi th-eyitate of. propagation of inflammation vof-the mixture, 1 Back-flash may be prevented in two '-way s :'(a) by'the cooling'action'of. thewalls of'passagesthrough which --themixtur e flows, as when the -mixture is i caused to flow through aflsmall tube or narrow slit or other smallopeningforamulti .plicity of these, one common form of means for preventing back flashin this Way being the wire gauze screen, andanother being porous diaphragm of large enough fheat'ab sorbing' and dissipating capacity; and '(b) I by causing the mixtureto approach the com- Specification of Letters Patent: Application filed September 21, 1912. Serial No. 721,557. 7

Patented July 13, 1915.

bustion zone with a velocity greater than the rate of propagation-of inflammation. On the other hand, to prevent blow-off and to localize the flame cap or combustion surface at the desired place or combustion zone, the

velocity with which the mixture is moving at the combustion zone must not-exceed the rate of propagation of inflammation. Continuous and localized combustion of explo-' I ture to flow with a velocity greater than the 7' rate of propagation of inflammation and then reducing the velocity to the rate of propagation of inflammation and preventing dissipation of the-mixture or. diffusion with other gas, and burning the mixture at the surface at which the velocity becomes equal to the rate of propagation of inflammation. The first of these two'ways, that is, by the use of a flame-interrupting, cooling screen or partition, is of lessefliciency than the second and is of limited application because the maxlmum rate of combustion cannot be attained and because of the difficulty of preventing the feed passage way or screen from becoming heated and losing'its flame-inter: rupting property. v The present invention relates to the second Way of securing continuous and localized combustion of explosive gaseous mixtures.

In Letters Patent No.' 755,876, granted to .me March 22nd, 1.904, 'I have described and claimed the method-of burning explosive gaseous mixturesin this way which consists in causing the mixture j to move with a velocity greater than the rate of propagation of inflammation through the mixture and then reducing the velocity to the rate of propagation of inflammation and preventing.

difi'usionWith-other gases by causing the mixture to. spread out so that the successive surfaces of 'uniformvelocity shall have adjacent points in any such-surface at substantially thefsame distance from the place Where thespreading begins and burning the mixture at'the' surface at'. which the velocity. is equal to the rate of propagation of inflam mationp In burning explosive mixtures in accordancev with the present invention, the mixture is caused to flowin one,or a number of jets or, streams with a velocitygreater than: the rate of propagation .of inflammation through the mixture and while flowing unconfined to impingeupon the face' of a freely porous and permeable 'bed of suitable material, whereby it is caused tospread out laterally with loss of velocity and to enter or tend to enter the pores or passages of the face of the bed, the degree of porosity of the bed, and the velocity with which the mixture is moving and the'size' and character of the jet or jets, andwill either burn at the surface of the bed or enter and flow through the pores or passages of the bed before burning a greater'or less distance ac-' cording to the character ,of the explosive mixture, the permeability of the bed, and the-velocity, size and characterof the impinging jet or jets. Ifthe velocity of flow of an impinging jet is sufliciently great, the mixture after spreadingat the surface of v the bed and havingfits velocity thereby reduced will enter the bed to have-its velocity still further reduced as it advances through the bed until it reaches a surface or zone at which the velocity of flow equals the rate of propagation of inflammation and at which the combustion will be located, the products of combustion then escaping through the bed beyond the surface of combustion or flame cap; and if the velocity of flow is great enough and the bed thin enough the flame cap may be located at or adjacent to the rear surface of the bed. If, however, the velocity of the impinging stream of mixture is such that equality between the rate of propagation of inflammation and flow velocity of the mixture is attained at the surface of the" bed against which, the mix-.

ture impinges, then the flame cap or surface of combustion will locate. closely against or partly within the superficial layer of the bed, the products of-combustion as before passing onward through the pores or passages of the bed. In such case the bed need not be of a character to cause gases flowing through it to expand and lose velocity, but need only be of a character to provide for theescape therethrough of the products of combustion, and need not be of any considerable thickness, a comparatively thin perforate, or porous diaphragm or plate being sometimes suflicient; If, however,

; ized at the impact surface.

the surface of combustion or flame cap is.

to be located withinthe bed or at the rear surface thereof, the bed should be. of such a character, either by having intercommunieating passages or expanding passages, or passages which are both expanding and in tercommunicating, that the mixture will be caused to spread out and have its velocity reduced as it advances through the -bed. A bed of broken or other granular refractory material with the pieces either loose or bonded meets the requirements, whether-the combustion is to be located within or at the rear surface of the bed or. atthe near or impact surface of the bed. v 0 The invention finds its greatest advantage for some purposes when the flow of the mix tureis regulated to locate the combustion at the impact surface of the bed. With the free escape of the gases of combustion through the bed beyond the impact face, and if thesurface of the bed is of a proper character, the outwardly facingsurface of each part and particle of the face of the bed. will be actually or. practically in contact with a part of the explosive mixture at the time when its velocity has been reduced'to the rate of propagation ofinflam'matiomso that combustion will takeplace-against such face. The interposition of unburnt or burnt gases betweenthe surface and the burning gas is thus avoided, and the temperature of all parts of the surface of the impact face,- of the. bed is raised/to the highest value physically possible so that it becomes highly incandescent, radiating both heat and light to a high degree. If the combustion is located at or near the rear surface of the bed,

such rear surface will then be'incandescent' and radiate heatand light, butit'will not become so highly incandescent as does the impact surface when the combustion is local- Ifthe bed be extremely thin, the rear surface may be so close to the impact surface as to eliminate any distinction with regard: to the location v of the flame cap at one orthe other and both will be highly incandescent, radiating both heat and light.

Burning the 'mixture at the impact face v of"thebed is included in the method claimed broadly herein,'but the method of burning the mixture at the impact surface as distinguished from burning the mixturewithin the bed as claimed specifically herein forms the subject matter of'an application filed by me on the 21st day of September,

1912, Serial No. 721,558. It should be noted that whether the coin bustion is located at the impact surface or beyond, the heating of the advancing mixture as it'approaches the surface :of combustion tends to increase the rate of propagation of inflammation, and a similar acceloration of the rate of combustion is believed 30 to be contributed by the incandescent solid matter; thus promoting the attainment of equality between the rate of propagation and flow of velocity, and increasing the amount of mixture that can be burned at a given surfaceand Within a given space.

The impact bed of an apparatus for use in practising my method may be of any suitable character or construction to provide the necessary pores or passages for the escape of the products of combustion, and for spreading the gaseous mixture when the combustion is to be'located within or at the far side of the bed, and may be of any suitable material. For a lasting or permanent bed, a suitable refractory material,

- that is, one which will withstand the degree of heat to which it is subjected, must be used. The degree of porosity and permeability of the bed should be such, if the combustion is to be located within the bed, as to permit the desired amount of mixture to enter and flow therethrough within the de-- sired extentof the bed; and if combustion is to be located at the impact surface there should be such a degree of'porosity and permeability as will permit with a given rate of feed of mixture the combustion of that mixture substantially in contact with all of the physical surface over which the advancing stream spreads. As before stated, if the combustion is to be located within the bed or at the far facethereof, the bed should be formed to cause the mixture to spread out and lose velocity as it advances through the bed, being for this purpose formed with inter-communicating or expanding passages for the gas flowing therethrough, or with passages both inter-communicating and -expanding;'- but, on the other hand, if the. combustion is to be lo-' cated at the impact surface of the bed, the passages through the bed need be only of such character as to provide for the free escape of the products of combustion and.

need not therefore be inter-communicating or expanding. The surface of the bed, if the combustion is to be located against the impact surface, and preferably. in all cases, should be of such a character, or have its surface particles or parts so shaped, as to promote proportionate passage of the mixture between the parts or particles and to prevent to the greatest degree the retention of a dead layer of gas on the side toward which the mixture is advancing. The shape of the impact face of the bed will vary according to the character and shape of the jet or jetsof mixture caused to impinge thereon. On the other hand, the-bed may be of various shapes according to the purpose to which the invention is, to be applied, and a single bed or a number of beds suitably grouped and arranged may be employed, the character and arrangement ofthe jets of vided state in proper proportions,- that is, in

proportions such that the mixture will have the property of self-propagation of inflammation. For producing the highest temperature, the oxygen should be undiluted and the mixture should contain oxygen and combustible matter in chemical combining proportions at the time of combustion; but there may be an excess of either the combustible matter or the combustion supporting gas within the limits which determine the property of self-propagation. The mixture may be varied in this respect according to the desired character of the products of combustion, that is, whether it is desired that theproducts shall be neutral, oxidizing or reducing. Also, the mixture may of course contain neutral gas such as nitrogen, carbon dioxid or water vapor,

so long as the amount of such neutral gas is not sufficient to make the mixture nonexplosive. w The accompanying drawings illustrate simple forms of apparatus adapted for'carrying out my improved method.

In said drawings: Figure 1 shows a simple form of single jet apparatus partly in section. Fig. 2 is a similar view of another illustrative form of apparatus; Fig. 3 is a sectional view illustrating a further, modified form of apparatus; Fig. 4: is a similar view of another form of apparatus; Fig. 5 is a similar view of a form of apparatusin whichthe fuel and combustion supporting gas are supplied from separate nozzles; Fig. 6 is a similar view of an apparatus having a, thin sheet; Fig. 8 is a section taken on line 8 of Figs. 6 and 7. Fig. 9 isa face view of a device for supplying a plurality of jets of the explosive mixture.

Referring first to Fig. 1, 10 represents a porous and permeable combustion support '20 ing bed against which a jet or stream of the explosive mixture is directed by a dischargevvPipe or nozzle 11. The ixt be v y supplied to the nozzle 11 from any suitable source or by any .suitable means, as for ex-..

ample, by the means shown, by which a mixture of a fuel gas and a combustion sup porting gas is supplied, and the mixture should be. supplied under sufiicient pressure to cause the jet or stream issuing from the,

nozzle to move toward the bed with a Vebustion supporting gas, the fuel gas and combustion supporting gas being supplied to vthese tanks by suitable means adapted to maintain the desired pressure therein. An outlet leads fromeach tank controlled by valves (1 and g respectively, and from these outlets .a supply pipe 12 leads to-the discharge pipe or nozzle 11. The valves (1. and

g serve to control the proportions of fuel gasand combustion supporting gas in,the mixture, and the velocity of flow of the -mixture from the nozzle 11 mayalso be con-- trolled by these valves. The proper proportions of fuel gas and combustion sup; porting gas, that is, proportions such according to the nature of the constituentgases that the mixture will have the property of self-propagation of inflammation, may be readily determined by experiment. When the jet I or stream of mixture issuing from the nozzle 11 strikes the face of the, bed 10 it will spread out or mushroom and lose a part of its velocity,

' and, if still unburned, will then enter and flow through the pores or passages of the bed and escape therefrom. at points deter mined by the character and shape-of the bed, the velocity'of the flow beingcontinually decreased as the distance from the im-' mit the gaseous mixture to expand or spread pact face of the bed increases provided the bed is ofv such a character as to cause or perout laterally as it advances through the bed. When the mixture is ignited the flame cap or surface. of combustion will locate where the velocity of flow is reduced to the rate of propagation of inflammation; By properly I adjusting the supply ofmixtureby means of the valves (1 and g to control the velocity of the jet issuing from the nozzle 11, the

flame cap or surface of combustion may be caused to locate, as already explained, either i at or against the impact face (i of the bed,

or within the bed at a greater or less distance beyond the impact face, as indicated, for

example by the dotted lines 6 and 7. The

location of the flame cap, and also the amount of spreading of the mixture atthe face of the bed, might also becontrolled by moving the nozzle-toward and away from the bed. Whether located at the impa face or within the bed, the greater part of the products of combustion will pass on through the pores or, passagesof the bed to escape from apart of the surface of the.

bed other than the impact face through which the jet or stream of mixture enters.

As there isa very considerable reduction in the flow velocity of the mlxture when it strikes and spreads out over the impact-face located at the impact face under quite con-1 of the bed, the combustion will remain f siderable variations in the velocity of the im pinging jet, so that an extremely accurateadjustment of the velocity or rate of supply of the gas is not-necessary in order tov maintain the combustion in .this position. It

should be noted that if the explosive mixture should contain an excess of fuel beyond what i will combine with the oxygen in the mixtureas it reaches thecombustion zone, the unconsumed fuel will pass on from the combustion zone with the products of combustion andwill burn at and beyond the exit face of the bed or wherever it may besupplied with additional oxygen from the atmosphere; or otherwise. It might also be noted here that some air may be entrained by the jet between I the nozzle and the bed, so that the mixture may contain a somewhat greater proportionate amount of air when it reachesthe 1 bed than it has at the nozzle. In order that the combustion zone or surface may co-incide,

more or less accurately with the impact face of the bed throughout the greatest possible or a considerable extent of the impactface,

the impact face should-be shaped according to the character of the jet. With a single I solid jet issuing from a cylindrical orifice,

and-with the mixture impinging at substan bed, the impact face should be of a suitable tially right angles against the faceof the 7 circular "concave shape as'indicated: by this figure. It is also desirable to' have the. im-- pact face of. the bed so shaped when the roe combustion is tobe. located within the bed since the flame cap or. surface of combustion will'then be caused-to take a more flattened v if a solid cylindrical jet were caused to "or spread; out shape than would be the case 1 strike against an impactfbed' having a generallyflat surface v In F ig.- 1. I have,shown the combustion supporting bed as formed of amass of loose broken or other Igranular refractory ma: terial, such as chrome ore, alundumor magnesite, in a suitable container 14. If a com' fparatively weak mixture is to be burned,

pieces of fire brick of suitable sizemay be" used. With such a bed the products of combustion-will escape from portions of the upper surface of the bed other than the impact face, as indicated by the arrows, or the receptacle 14" might be made with outlet openings 15 as indicated by dotted lines,

. Fig. 2 shows also a singlenozzle for dis- 7 charging a solid jet against aporous and permeable combustion supporting bed havq ing a concave impact face. As shown in this figure, however, the bed has itsrear or far surface open so that the products ofcombustion may escape therefrom as indicated by the arrows. Such a'bed or diaphragm open on both sides maybe formed in'any suitable manner, as for example, by bonding together in a mold or otherwise pieces of granular refractory material, or by molding a plastic mass to which has been added matter which on being heated will disappear and leave a suitably porous and permeable bed or diaphragm. With this'bed, the combustion may be located as before described either at the impact face or within the bed by suitably adjusting the velocity of the impinginggjet, and if the velocity of the jet is sufliciently great the flame cap or surface of combustion may be caused to locate at, or close to, the rear surface of the bed so as to cause such rear surface to become heated to incandescence and to radiate both heat and light, though not to the same degree as the near or impact face when the flame is lo cated at such near or impact fact. When the rear face of the bed is to be heated to serve as a radiating surface by having the combustion located at or near it, 'it will best be shaped according to the character and arrangement of the impinging jet or jets; for example, with a single solid jet the rear surface of the bed should be of a more or less convex form as shown in Fig. 2 so as to correspond in shape more or less closelywith the shape of the flame cap or surface of combustion. Fig.

2 also shows means for supplying an explosive mixture of sprayed or atomized oil and air. Oil is supplied through a pipe 16 to an atomizingdevice 17 to which air under pressure is supplied through pipe 18 and from which the atomized oil mixed with air is discharged into a chamber 19 from which the mixture of oil and air passes to the nozzle 11 to be discharged against the bed 10. The pipe 18 is connected with a suitable tank or other source of supply of air under pressure, and a pipe leading from the pipe 18 directly to the mixing chamber 19 is provided for supplying additional air to the mixture in the mixing chamber 19. Valves 21 and 22 control the supply of air to the atomizing de ice and the supply admitted directly to the mixing chamber respectively. Connections might obviously be -provided for supplying a number of discharge nozzles with mixture from the chamber 19, and other suitable devices might be used for supplying an explosive mixture of sprayed or atomized oil fand air or other combustion supporting gas. In a similar manner an explosive gaseous mixture of air and coal dust or charcoal dust might be burned.

' moving with alower velocity and its outer portion with higher velocity. For receiving such a jet the impact face of the bed instead of being concave should be of a general convex form as shown in this figure in order that the velocity of the mixture at the impact face may be substantially uniform or more nearly so than would be the case if such a jet were discharged against a fiat or concave bed. Also, the bed shown in this figure is intended for combustion at the impact face only, the pores or passages through the bed having a substantially uniform capacity or cross area from the impact face to the rear surface of the bed, and being thus adapted to serve to carry away the products of combustion but not to cause a gradually decreased velocity of gas flowing through them.

Fig. 4 also shows a porous bed having noncommunicating passages extending through the bed from the impact face to the rear surface, but as shown in this figure the passages increase in size from the impact to the rear surface of the bed, such expanding passages allowing gas flowing through them to expand so as to advance in increasing volume and with. decreasing velocity. A bed of this form is therefore adapted not only for combustion at the impact face, but also adapted for use when it is desired to have the combustion locate beyond the impact face within the bed. With a bed of this kind, how- 'ever, localized combustion within the bed cannot be maintained under such wide variations in the flow velocity of the mixture entering the bed as with a bed having suitably formed inter-communicating passages such: as are secured by forming the bed of suitable sized pieces of broken material.

Fig. 5 illustrates an apparatus in which a the fuel gas or other form of fuel and the combustion supporting gas are supplied separately from supply pipes or nozzles 22 and 23 respectively, set so that the jets or streams of fuel and combustion supporting gas respectively will meet at or before reaching the impact face of the bed to form an explosive mixture which, driven by the force of one or both of the jets, spreads out and burns at the surface of the bed or within the bed as before. This form of apparatus'nia-y be used where the fuel is in the form of gas, but is especially adapted for use when oil or other liquid fuel is supplied in the form of a jet or spray to be vaporized as it reaches or approaches the impact surface of the bed where the combustion is located,the vapor then mixing with the air or other combustion supporting gas and spreading out therewith over the surface of, the bed to be burned. I I As before stated, jets of various forms, and any desired number of jets arranged in various ways, may be employed in connec tion with suitably shaped and arranged pomug and permeable beds. Fig. 6 shows a multiple jet nozzle 25' for supplying a row ranged to discharge radial or diverging jets,

of jets, and Fig. 7 showsa nozzle 26' hav-' ing an outlet slot for supplying the mixture 7 6 or Fig. 7. Fig. 9 shows a face view of a nozzle or supply chamber having a number of discharge openings or nozzles distributed over its surface. The porous bed receiving the jets discharged from such a device, if the jets were parallel jets all of the same size and velocity, would best have a plain impact face bounded by a raised edge portion; If, however, the central or inner discharge openings or nozzles were made larger than the outer ones so. as to supply jets of greater energy, or if the nozzles. were arthen the impact face of the combustion bed i shouldhave a more generally rounded concave form, while if the inner jets were less' powerful than the outer ones, the bed should best have an impact face of convex form.

-What is claimed is:

1. The method of burning explosive gaseous mixtures, which consists in supplying the mixture continuously and driving it unconfined toward the surface of a porous and permeable bed whereby the velocity is reduced, and'burning the mixture where the velocity is equal to the rate of propagation of inflammation through the mixture, and permitting the products of combustion to escape through the passages of the bed.

2. The method of burning explosive gaseous mixtures which consists in supplying the mixture continuously and driving it unconfined toward the surface of a porous and permeable bed whereby the velocity is reduced, then further reducing the velocity to the rate of propagation of inflammation by causing the mixture to spread as it advances through the bed beyond the impact face of the bed, and burning the mixture where the velocity is equal to the rate of propagation of inflammation and permitting the products of combustion to escape through the passages of the bed.

3, The method of burning explosive gaseous mixtures which consists in causing the mixture to flow unconfined with a velocity .greaterthan the rate of propagation of inflammat1on-through the mixture, and then reducing the velocity to the rate of propagation of inflammation by interposing in the the bed.

I 4. The method of burning explosive gaseous mixtures which consists in causing the. I

mixture to, flow unconfined with a velocity greater than the rate' of propagation of inflammation through the mixture, then reducing the velocity by causing the mixture to flow against the surface of a porous and permeable bed of refractory material, then further reducing the velocity to the rate of propagation of inflammation by causing the mixture to spread as it advances through the bed beyond the impact surface of the bed, and burning the mixture where the velocity is equal to the rate of propagation of inflammation and allowing the products of combustion to escape beyond the combustion zone. 5. The; method of producing heat, which consists in combining a fuel in a finely divided state with a combustion supporting gas in proportions to form an explosive gaseous mixture, and driving the explosive mixture thus formed unconfined at a velocity.

greaterv than the rate of propagation of inflammation of the mixture against the surface of a porous and permeable bed of refractory material the temperature of which is sufiicient to cause ignition of said mixture, and thereby heating and igniting the mlxture.

6. The method of producing heat, whi-c consists in combining a fuel in a, finely divided state with a combustion supporting gas in proportions to form an explosivegaseous mixture, driving theexplosive mixture permitting, the products of combustion to escape through the passages of the .bed.

' In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

I CHARLES E. LUOKE.

Witnesses:

FRANK C. ERB,

IA.L.KENT.

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