US1222922A - Process of burning gases. - Google Patents

Description

W;A.BUNE.1W. WILSON & c. D. lvlccouRT.

PROCESS 0F BURNING GASES. APPLICATION FILED JuLv|l.19l2. RENEWED SEPT. 8, 1916.

Patented Apr. 17, 1917.

vforms based uponand contains subject-matter taken Ere.

WILLIAM anrnun. BONE AND JAMES wrLLraiu WILSON, or LEEDS, man oYErL noue- LAS' MUCOURT, OF LONDON', ENGLAND,

ASSIGNORS T0 RADIANT HEATING LTMITED,

0F LONDON, ENGLAND, A BRITISH CORPORATION.

Application led July 11, 1912, Serial No. 708,852.

To all whom t may concern:

Be it known that we, WILLIAM ARTHUR BONE, of Leeds, in the. county of York, England, JAMES WILLIAM WILSON, of Armley, Leeds, in said county, and CYRIL DOUGLAS MCCOURT, of 4:5v Braxted Park, Streatham Common, London, S. W., England, subjects of the King of Great Britain, have made certain new and useful Improvements Relating to Processes of Burning Gases, of which the following is a specification taken in connection with the accompanying drawing, which part of this application, which is from our copending United' States application, Serial No. 586,058, filed October 8,1910.

This invention relates to processes of utilizing the accelerating influence of the incandescent surface of a highly porous refractory diaphragm upon the combustion of a suitable explosive mixture of gaseous fuel and air fed in-large volume through the diaphragm toward its heated outer surface, so that aV large proportion of the thefuel is liberated as radiant energy fromthe incandescent surface so as tobe available in connection with manyindustrial gas heating operations. Whenv `an exploslve mixture of coal gas and air, for instance, in their combining proportions or with air in slight excess thereof is passed at suitable velocity throughthe pores or interstices of a suitable. crous refractory diaphragm into its ncan accelerated andsubstantially nameless combustion of the gas takes place within the interstices, pores or .partslof the incandescent diaphragm layer which are .more or less impregnated or in .contact with, the gaseous mixture; and energy thus.. developed in large amounts by this intensified, completel and efficient combustion is absorbed -by-the adjacent surface layer of the diaphragm and maintains it in a state of incandescence, thus securing a very convenient and eflicient source Y*of radiant energy.. This highly accelerated or intensified surface combustion seems to be due tothe emission of charged corpuscles or electrons from such incandescent solids, and the consequent formation of layers of electrified or ionizedr gas in which the chemical changes incident to combustion proceed, .with extraordinary'gv rapidity. x Tt has been demonstrated that-theiincandescent VJmal bustion of an explosive potential energy of escent surface layer a many fold" PRQCESS OF BURNJING GASES.

@mm Specification of Letters Patent.

Renewed September'il, 1916. Serial No. 119,139.

solid plays anactive, and important part in the combustion of/the explosive gaseous mixture under these conditions, the particles of the incandescent solid apparently .forming a composite system with cent molecules of the combining that such combustion complex acts ner very gases, so in a mandif'erent from what occurs in norflame combustion. For example it has been proved that the presence of water vapor certainly accelerates, if it is not essential to, the normal flame combustion of carbon monoxid in air or oxygen, whereas the presence of even Aa small quantity of water vapor such as -will saturate the gases at 18 C. greatly retards the surface commixture of carbon monoxid and oxygen'in contact with heat.- ed ireclay surfaces. Another thing which indicates the distinctive and qualitative difference between such surface combustion and normal liame combustion is the fact, that in ordinary combustion methane and other hydrocarbons have much greater afinity for oxygen than either hydrogen or carbon monoxid; while in surface combustion these selective' affinities are completely reversed, apparently because of the controlling action of the heated solid particles'on the manner of combustion.

This invention is adapted for the combustion of a large variety. of combustible gaseous material, as for example blast furnace gas, producer gas, water gas, which may be carbureted, coke oven gas, coal gas, petrol air gas and similar hydrocarbon gas and other combustible vapors, natural gas and mixtures thereof, all ofgvhich are hereinafter referred to as combustible gases, although the temperature attainablel in any particular case will naturally depend upon the calorifcJgintensity '0f the gaseous material employed. The combustible gas is combined with air or other available supporter of combustion `preferably in substantially the combining proportions or with a slight excess or deficiency of air, although the proportions of the constituent gaseous materials may. varyv considerably and still secure an explosive vgaseous* mixture, such as mationh possibly under conditions of increased pressure and temperature;

In the illustrative forms of apparatus for f 't `verted convex carrying out this invention shown in the drawings in a somewhat diagrammatic Way, Figure 1 is a verticalcentral section through a form of diaphragm apparatus.

Fig. 2 is asimilar View through a pair of opposed diaphragms. j

Fig. 3 is a similar View showing an indiaphragm in connection with a hood and flue.

Fig-4 shows in section a tubular diaphragm unit.

. Fig. 5 is a diagrammatic view showing a magnified section ofthe diaphragm structure; and

. Fig. 6 is a similar view showing diagrammatically one of the channels in such porous diaphragms.

The porous refractory diaphragm may be given any suitable shape so as to-liave the desired form of incandescent outer surface from which the heat is transmitted. In the illustrative form of diaphragm unit shown in Fig. 1 the permeable or porous diaphragm 1 may be in the form of a flat plate of suffici ently refractory material preferably formed of agglomerated or united particles or grains of substantially uniform size so as to form tortuous channels for the passage of the explosive gaseous mixture through the diaphragm. The diaphragm which may be an inch or so thick may be mounted in any desired way, as for instance, by being supported in a suitable casing 2 of iron or other suitable materialy which may be formed with a suitable recess behind the diaphragm communicating with the injecting pipe 3 for the' explosive gaseous mixture which for example may be formed by forcing the combustible gas through'the inlet pipe 6 in the d esired amounts controlled by the gas valve 7 while air is similarly supplied under the desired pressure through the air inlet pipe L1 to the extent determined by the adjustment of the air valve 5. In order to keep the edge of the diaphragm cool it is desiiable to minimize the discharge of gas from this part of the outer or discharge surface S of the diaphragm in any suitable way, as for instance applying a suitable impervious coating 11-to the edge and adjacentinn'er face ofthe diaphragm. A suitable impervious coating for thisV purpose may formed of a mixture of finely groundburned ireclay and sodium silicate which'maybe applied warmed. sufficiently to cause setting of Ithis cement-'like material which forms/ a hard material somewhat like Portland cement or limestone. Plaster of Paris or other impervious cement-like material may also be used for this impervious coating or the de'- sired part of the diaphragm may be rena suitable glaze formed duriiig'its manufacture. 4The diaphragm is preferably mounted within a suitable seat this instance in moistened condition and .their 10 thecasing/ of suchshape. as to substantiallyconform to the edge of the diaphragm which is preferably located so as to be proltected by the edge or flange 9 of the casing.

Any suitable cement or luting material may be used to hold the diaphragm within the casing, a mixture ofinely groundburned fireclay 1 and sodium silicate whichm'ay becaused to set by suitable warming, or other suitable cementitious material, such as plaster `of Paris, asbestos paste, o r whitelead composi- -tions may be used. Such porous refractory mediums when in the form of coherent diaphragms may be arranged horizontally, vertically or at anydesired angle andthe hot outer surface vmay be either the upper or Several diaphragms may be lower surface. arranged in any desired way to supply heat to various parts of an object and for grilling er toasting purposes, for instance, two diaphragins may be arranged opposite each other. As indicated in Fig. 2the incandescent diaphragms 15 and 16 are placed at any suitable distance apart so as to heat both sides of the article placed between them. The diaphragm 15 may be mounted Within a suitable casing 17 connecting with the injecting pipe 18 and formed with a suitably connected support, if desired. The opposing diaphragml may be mounted in a similar support 19 having the injecting pipe 20.

In some cases instead of using phragms many other special forms or contours suited to special purposes may be used, such, for example, as the dome-shaped or convex diaphragm shown in Fig. 8. In, this case the porous refractory diaphragm 21 is shown mounted in inverted position, in the iron or other suitable `casing 22 so as to have the` outer hot surface of the diaphragm pointed instance in its upper portion or for heating or evaporating liquids or other material placed beneath the diaphragm. As indicated, the

as for instance, ireclay or preferably plain diadownward so as tobe suitable, for for heating a room when 'mounted diaphragm and its connected casing may in be convenientlyfsupported by the injecting pipe 23-zlfor explosive 'gaseous v mixture, and if desired a suitable hood 24 may be mounted in'connecti'on with thediaphragm so as to carry ofthe products of combustion therefrom in-connection with a suitable flue; such as25. A form of tubular diaphragm '26 is shownin Fig. 4 as`mounted Within a suitable'casin'g or support 27 of 'iron' orother suitable material so that the explosive-:gaseous mixture supplied to the diaphragm through the injecting. pipe 28 maintains the outer, surfaceyof theporou's diaphragm in incandescent condition. The explosive gaseous mixture may be formed and fed to any such refractory diaphragms which are sufficiently porous by a suitable injector device in which either the combustible or combustion supporting constituent may be under pressure and be discharged with sufficient velocity to draw in and mix the other component ofthe explosive mixture and feed the same with suiiicient pressure through the diaphragm. In Fig. 4 the injector deyice may as indicated comprise the curved injector throat 29 with which the injector nozzle 31 co'perates so as to draw in additional gaseous material through the annular passage 32 the size of which may be regulated by adjusting the position of the valve 34 threaded or otherwise adjustably mounted on the nozzle, for instance. The supporting casing 33 communicating with a suitably valved supply pipe may be used to connect the injector throat with the pipe 30 communicating with the nozzle so as to allow the entrance of air o-r other gaseous supporter of combustion around the nozzle when the combustible gas is' disvcharged therefrom at a velocity pressure of a few pounds per square inch which is suiiicient to produce a pressure vbehind the diayphragm of an eighth or a quarter of an inch of water or more. The valve in the gas supply pipe may be us/ed to regulate the amount of gas discharged from the injecting nozzle and the valve indicated in the air supply pipe may regulate the amount of air drawn 1n.

These refractory diaphragms of a high and quite uniform degree of porosity may be manufactured in a numberl of ways, as for instance, by` suitably uniting refractory porous granules of substantially uniform size so asto give a high degree of porosityv and permeability to the diaphragm which is penetrated by tortuous. gas passages `formed by the network of spaces or interstices between the refractory particles or grains of which the up. Porous iireclay is a satisfactory ."fna- 'terial for such diaphragme and may be readily crushed or 'ground in any desired way into particles or grains of the desired size. The granules for making any particular class ofdiaphragms are substantially uniformly sized, that 1s, granules passing asieve havin to the linear inch are selecte from objectionable fine material by separating therefrom 'all particles which will pass a 50 mesh sieve.- Another size of gran-f ules useful for such diaphragms for less explosive a 16 mesh sieve and retained by a 32 mesh sieve. Still largersized granules, suchas are suitable for making diaphragms which may be generally used for burning coal gas and illuminatin gas are those passing an 8 mesh sieve andretained by a 16 mesh sieve. These porous granules may be united in any ldesired waypreferablyby means which will not destroy or undsirably impair the diaphragme are made.

for instance, the:V

30' meshes and freed' gaseous mixtures are those passingmolded while in this l their porosity of each of the granules. This ma be accomplished by the use of suitable binding agents, such as incorporating with the granules a small percentage of feldsparor a mixture of fel'dspar with a little iiuorspar to the extent of ten per cent. or so of the granules. Such binding material in dry finely powdered form may be incorporated with the granules by iirst wettingthemfand then thoroughly stirring them with! theidry binding material which thereby coats the particles which may then he immediately moistened condition. The molded diaphragms are then burned at a high temperature in a suitable pottery kiln or other furnace so that the temperature is carried considerably beyond the Iusing point' of the binding material and this causes the binding material to unite or fuse together the adjacent points of the rough porous material is sufficiently absorbed into the granules to leave them with rough unglazed surfaces so as not to undesir'ably minimize their porosity)I rll`he diaphragms areformed by being burned atcalcining temperatures greatly in excess of workingv temperatures the particles are firmly and sufficiently rigidly Ih e'ld in position. `'For instance, diaphragms may Abe burned attemperatures of 1300 to .1400 degrecs C. and operated at teinperatures of 800 or`900 degreesnC. with good results. 1t\

`is also desirable to carefully. mold these diaany possibility o crushing the-particles or undesirably packing them. 1t visalso des sirable to remove the surfaceof the bakedV diaphragms whereA the particles have become alined as by being in contact with the smooth mold surface and this may. be donel in any desiredv way as with a rasp before they are usedf For some purposes alsomit is .not desirable to use as the discharge or outer active surface ,of the diaphragms the surface which has been in contact witli'the mold`,f"but to use this surface for the inner surface through which the gas enters. 1nl

granules while the vbinding working temperatures so .that at all this way diaphragms may be formed of en# tremely high and uniform porosity, the degree of porosity, that is, the proportion vof porous cavities and spaces between'the particles 'or granules being as high as 50 per cent. or so in some cases. For some special purposes it is sometimes desirable to form the diaphragms with outer discharge sury faces of'coarser particles and with bodies or inner layers of finer particles which can inch mesh, which of course be conveniently effected when molding the moist material.

The substantially uniform size of the granu les and the tortuous nature of the gas passages between them are desirable in highly permeable diaphragms suitable for operation under low gas pressures. The size of the granules and consequent size of gas passages and permeability of diaphragms of this character should be so chosen as to give the proper operation ,with the particular kind of gas with which they are to be used, the size of granules being in all casesc small enough so that together with the tortuous character of the gas passages and the greatly increased cooling effect due to the impinging action and rough surfacesof the granules forming these passages, flashback through the diaphragml passages is greatly minimized and practically eliminated under operating conditions with the particular explosive gaseous mixtures used. Diaphragms an inch and a quarter or so thick may be formed in this way of porousireclay granules of between one-eighth and one-sixteenth give good results with explosive coal gas and air mixtures supplied under pressures of about one-eighth of an inch of` water, and such diaphragms may burn as much as 75 cubic feet or so of coal l v A diaphragm similarly gas or 400 to 500 cubic feet of explosive coal gas and air mixture per hour for every square foot of diaphragm surface, thus` maintainingthe outer heated surface of the diaphragm at a temperature of about 850D C. or so under freely radiating conditions. formed of granules of substantiallyv sixteen-mesh size will burn a similar amount of explosive coal gas mixture, but requires somewhat higher pressures, about one-quarter lnch o r so for the same diaphragm thickness. More explosive or inflammable gaseous lmixtures such as those comprising water gas containing somewhat larger aconsiderab y finer diaphragm to eifectlvely suppress backflashing or quick backfiring therethrough, and for such explosive gaseous mixtures the diaphragm-may be formed of granules as in'e as about 30 orl 50 mesh' or even ofs'till finer granules of between 50 phragms and 100 mesh size in the case of more in- .iammable water gas mixtures. l

,-The laction of suchporous refractory diain effecting the accelerated surface combustion of explosive mixtures can he; un-

-Aderstood by reference to Fig. 5 which diastructure on a greatly grammatically illustrates the' diaphlfafll magnified scale. T e

outer granules `or particles 40 of porous'` re.-

the combustion of the explosive gaseous mixroportions of hydrogen require conduct-,mg plate or y tures at which fractory material are. the ones maintained '1n"\ a highly heated or incandescent' condition by v tures injected against themso as to maintain them in this highly heated condition in which they can radiate heat to each other and from the `exposed outer surface of the diaphragm. As may be seen by reference to theAV portion of these granules within the plane ofthis section the granules not only have rough outer surfaces, but have internal pores such as 42 communicating in many instances with the outer surfaces to form cavi- 'ties which the gases may readily penetrate. These particles cles 4:1 are firmly united, but have relatively large cavities or interstices, so that the entire diaphragm is formed with a net work or concatenation of' these communicating spaces or channels. Fig. 6 illustrates dia'- grammatically the character of one of these tortuous gas passages or channels ,44 through a diaphragm cof this character, the section being taken along the' irregular line following the greatest cross-section of thisparticular channel through the porous particles. These same factors promote the surface com-, bustion action occurring in the hot outer layer of the, diaphragm several granules thick. The explosive gases are here brought into impingement with the rough incandescent surfaces of the granules so that penetration and contact with the gas is greatly proand the similar inner partimoted and highly accelerated combustion takes place much more effectively thanv drilled with A that it can undesirably heat by conduction the rearward layers of the diaphragm and thus cause the zone of surface combustion of the explosive gases to slowly andprogressively move back away from the outer surface. This back heating action occurs when, for example, two coal gas diaphragme are arranged with their incandescent surfaces close together, or when a refractory nonthe like is moved against hot diaphragm, and may also take place when excessive amounts of the gaseous mixtures are .being "burned in the diaphragm so that the heat developed exceeds that which can be properly dissipated from the radiating diaphragm surface at the relatively moderate incandescent temperait seems preferable to operate these diaphragms. Whensuch back heating takes place the outer diaphragm surface actually frequently cools of after the combustion zone or incandescent layer has moved backward into the diaphragm, and

or close to a instead of a substantially uniform 1ncandes 130 i the'explosive gases in the conditions are restored.

ated by surface combustion,

lse

cent diaphragm surface cent surface darker spots appear and in many instances the outer surface cools below a bright heat when the combustion layer has retreated some distance. l/Vhen this slow retrogression or ypenetration of the hot combustion zone through the diaphragm occurs diaphragm chamber may become ignited, and it is of course desirable to quickly correct this undesirable action as by shutting off the gas supply and cooling the diaphragm or by considerably increasing the proportion of air mixed with the combustible gas supplied so that normal Then the relatively from the incandesshould be insured so as to radiate the heat as fast as it is generand prevent the progressive accumulation of heat and rise of temperature in the incandescent surface layer which undesirably heats the adjacent material and initiates such backheating. In normal operation. of such refractory diafreer radiation of heat Aphragm the explosive gaseous mixture continues to burn with accelerated surface combustion in the incandescent surface layer and this combustion may be definitely localized and maintained at the desired intensity by regulating the supply of explosive gases and the amount of heat radiation as by increasing or diminishing the freedom of raidiation, so as' to insure equilibrium and instance, in the coal counteract any unbalancing tendencies in the heating system. This back heating action is distinct from the ordinary backiashing or quick backfiring of explosive gaseous mixtures in tubes, such backiiring action being suppressed or eliminated in diaphragm operation by the greatly increased cooling effect on the asesof the small granules and the relative y large surface ofthe tortuous gas passages therethrough.A For gas diaphragms `referred to having granules of between one-eighth hood of 30 to and one-sixteenth inch mesh, the passages are of appreciable size and the porosity is so l great` that thee, total area of theI passages through the diaphragm is in the neighborsquare inches for each square foot of diaphragm surface. lBut nevertheless, no backiiring occurs with a properly made diaphragm of this character, and

the importance of the tortuous roughened character of the gas backflashing can be fact that only a square foot passages in preventing appreciated from the as much gas will pass through diaphragm of this character as I will' issue from an orice ornozzle about one-quarter or one-half inch 1n diameter under equal pressures. n gradually shutting off the gas supply to diaphragmslof this character the speed of the explosive mixture passing through the tortuous channels of the diaphragm is gradually reduced to zero, of the diaphragm structure is such as to prevent backflashing of the explosive gases in contact with the incandescent outer face of the diaphragm even under these conditions; and such diaphragms may be regularly operated when the speed of the explosive gases through the diaphragms is much less than the normal speed of backliashing of the mixtures.

It is of course understood that many other refractory substances such bauxite, ganister, preferably those having a suficiently porous character may be used to form the granules which may be united in many Ways to form porous diaphragms of this character. pVarious..tirebrick' compositions havel proved highly desirable, especially the more porous refractory materials of this character.

Having described these inventions in connection with a number of illustratiye embodiments, arrangements, proportions, materials, pressures, conditions, processes and orders of steps, to the details of which disclosure the inventions are not, of co/urse, to be limited, what is claimed as new and what' is desired to be secured by Letters latent is set forth in the appended claims.

1. The process of burning explosive gaseous mixtures which consists in causing the mixture to flow with a velocity less than the normal speed of back-firing of the mixture through tortuous passages of a porous refractory diaphragm to a highly heated surlface layer thereof, eecting combustion of the mixturewithin'said highly heated surface layer of the diaphragm, and preventing backlashing by the cooling action of portions of the diaphragm through which the mixture iiows on its way uto the combustion zone, whereby the combustion is localized within the surface layer of the diaphram and such surface layer is maintained in a. state of incandescence.

2. The process of burning explosive gaseous mixtures which consists in causing the mixture to flow with a velocity less than the normal speed of back-ring through tortuous passages of a porous refractory diaphragm to a highly vheated surface layer thereof, effecting combustion of the mixture with'n said highly heated surface layer of the diaphragm, preventing bacldiashing by the cooling action of portions of the. diaphragm through which the mixture flows on its way to the combustion zone, and permitting heat to radiate freely from said highly heated surface layerv of thel diaphragm, whereby the combustion is localized within the surface layer of the diaphragm and such surface layer is maintained in a state of incandescence.

' 3. rihe process of burning explosive gaseous mixtures which Aconsists in causing the mixture to flow with a velocity less than the as magnesia, f

normal speed of back-firing of the mixture `the diaphragm to impmge onthe through tortuous irregular sectioned passages of a porous refractory diaphragm to a highly heated surface layer thereof, effecting combustion of the mixture within said highly heated surface layer of the diaphragm, and preventing backilashing by causing the mixture as it advances through walls of the tortuous4 passages of the diaphragm, wherebythe combustion is localized within the surface layer of the diaphragm and such surface layer is maintained in a state of incandescence.

4. The process of burning gaseous fuel which consists in combining the gaseous fuel with a gaseous supporter of combustion in proportions to form an explosive gaseous mixture, causing the'l mixture to flow with a velocity less than' the normal speed of back-firing of the mixture through a porous refractory diaphragm to a highly heated surface layer thereof, effecting combustion of the mixture within said highly heated surface layer of the diaphragm, and preventing backlashing by the cooling action of portions of the diaphragm through which the mixture flows on its way to the combustion zone, whereby the combustion is localized within the surface layer phragm and such surface layer is maintained in a state of incandescence.

5. The process of ous mixtures which consists in causing the mixture to flow with a velocity less than the normal speed of back-firing through a porous refractory diaphragm to a highly heated surface layer thereof, effecting accelerated surface combustion of the mixture within said highly heated surface layer of the diaphragm, and preventing backfiashing by the cooling action of portions of the diaphragm through which the mixture flows on its way to the combustion zone, whereby the combustion is localized'within the surface layer of the diaphragm and such surface layer is maintained in a state of incandescence.

WILLIAM ARTHUR BONE. `JAMES WILLIAM WILSON.

CYRIL DOUGLAS MCCOURT. Witnesses:

M. G. SPALDING, CHARLES E. TAYLOR.

of the dia-- burning explosive gase

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