US961672A - Method of burning powdered fuel. - Google Patents

Description

H. R. BARNHURST. METHOD OF BRNING PWDBRBD FUEL.

APPLIGATIc-n HLBD su. 21, 1910.

961,672. Patented' Jun@ 14.1910.

ATTORNEY5 vUNITED STATES Parana. tiraron..

HENRY B. BABNHURST, OF ALLENTOWN, TPENNSYLVANIA, ASSIGOR OF ONf-HALF- TO HENRY GREGORY BARNHURST, OF CATASAUQUA, PENNSYLVANIA.

)IETHOD OF BURNING POWDEBED FUEL.

specification of Letters Fatent.

To all whom it may concern:

Be it known that l, HENRY ing at Allentown, county of `Lehigh, State of Pennsylvania. have invented certain new and useful liiiprorcinents. iii Methods of i Burning Powdered Fuel; and I do hereby and in spite of ilvc fari that, unlike ordideclare thc followiiiT to be a full, clear, and exact description o the invention, sueh as will enable others skilled in the art to which it a pertains to malte and use. the same.

Ally invention relates to improvements in cil'ecting the combustion, for industrial purposes, of fuel of such a character that ordinar expedieiits for burning it are attended with but indifferent results.

One of the materials for whose combustion the invention is particularly intended is anthracite ciilm, thatis to say, the fine screenings and other refuse from coal mixiing operations` which have accumulated in large quantities in the neighborhood of coal mines and coal breakers, and including the still more finely divided anthracite mud constituting the tailings of coal wasbcries.

v,The smaller sizes of anthracite coal are to Aa greater or less extent recoverable as such from tliecnliii, by various separating operations, and appear on the market under the names of bin'zliwhcat ricci and barley but this separation is not always commercially feasible, and even whenpracticed, there is always left a largegresidue, consisting of finer particles of anthracite, carrying a considerable percentage of ash-producing constituents, which residuo, in so far as I ain aware, has not heretofoicbeen successfully utilized as a fuel, although its percentage of combustible matter is sullicient to constitute ita valuable l'uel were it properly and completely burned. Bytlie prac- -tice of my invention, it is feasible to burn this euhn, whether with or without the preliminary separation therefrom of the smaller sizes of coal above specifically referred to,

muy bituminous coal, it' contains comparatively little ignilible hydrocarbon.

ln the practice of -my invention. l first grind the anthracite cnlm in a dry condition` to an exceedingly liuc powder, the grinding operation preferably -rcducing it to such a minute degree of subdivision that say 8574- of the mass would pass through a screen of No. 200 mesh. By the uid of an air current of suliicierit pressure, the finely. R. Baiixi nuasr. a citizen of the United States, residpnlverized and dili -ultly ignitible culmis injected imo my combustion chamber in the forni of a fuel cloud, and under such conditions that tlie cloud-like body as it enters,

the combustion chamber travels in close proximity to a highly heated ignition surface (preferably the lower surface of the arch of the combustion chamber) where it is ignited. It then returns upon itself in the form of-o loop, the outgoing branch of the loop radiating its heat upon t-he incoming branch in process of ignition, and preferably taking its exit from the combustion chamber in such manner that the products of' combustion will enveloo the conduit through which the mixture oli the pulver-ized Patented June 14, 1910.

culm and air is injected. This intersection Y.

of the products of combustion with the oonduit through which the fuel cloud enters tends to correspondingly preheat the latte-r,-

and has the additional function that at. this point a minor portion of the products of combustion is entraincd with and joins the incoming branch of the loop thereby assisting in its deflagration by adding to the fuel cloud the sensible heat of the combustion products thus entrained... Finali the.

main body ortion of the products o combastion, on caving the combustion chamber traverses the reverse side of the ignition wail or arch above referred to, thereby transmitting therethrough Yto the enteringfuel cloud such a large amount of heatlthat, in practice, itis found that e'cctive i nitioii or detla'ration of the fuel and its u tiinate practically complete combustion'can be relied upon.

ln the accompanying drawing, I have illustrated a form of apparatus which T h'avo found well adapted for the practice of my invention, and which, in operation, em-

bodies iny preferred plan for carryingit into cll'cct.

ln thc drawing, Figure 1 representen. longitudinal sectional view of in said p referred forni of apparatus; and fi, 2 represents a. cross-sectional view thcreo taken on a planeindieated bv thc line '2,-2 of Fig. 1. Similar letters of reference indicate simi lar parts in both views.

Referring to che drawing, A indicates the front outer wail of the furnace. structure, B the outer side walls thereof, and C the coinbustion chamber. One of the walls o f the los' l combustion chamber (preferably the arch a' thereof) is made quite thin, say nine inches in thickness or thereabont, and of refractory material conductive to heat. (the more rou'- ductive the better), and is intended to .serve as the ignition wall or arch lu-.reiubefore referred to, Accordingly, the pipe b through which theffnixtturel of air and pulrerized eulm is projected, and the surrounding conduit or twyez' l: through which an additional amount of atmospheric air is drawn in, are located just ont of line with tle inner surface of the wall or arch a, so as to direct the `incoming fuel cloud along and in close prox imity thereto.'

At its furthermost or rear end, thtl combustion chamber C is curved, as shown, and its walls are preferably made smooth throughout so as to minimize -thc formationv Spf interfering eddy currents. The exit port il for the products of combustion is located the temperaturevof the latter and thus to asv sist. in continuously maintaining it at thcV full ignition point.

Before injecting. into the combustion chamber the mixture of air and pulrerizcd culm, l heat the combustion chamber to such a degreeand in such manner as will bring it to the temperature necessary to initiate `the ignition and combustion of the mixture ot' air and pulverizcd culm which would otherwise not ignite. While this preliminary heating of the combustion chamber ma he etlected in various ways, such a`s by ma 'ing therein a wood tire, I find that it ma he quickly and eourenier-.tly brought to a iigh temperature by thereafter introducing,-V

throuqh the pipe b, the usual mixture of air and fihcly pulverizcd ordinary bituminous coal, which then readily ignites because of the large proportion of rich hydrocarbons resent in that fuel. mation chamber has been sufficiently heated, and particularly as soon as the inner surface of the wall or arch a Ahas been raised to thc temperature necessary for insuring and:

maintaining ignition of the mixture of air and ulverized cnhn, the snp ly of )ulverized Eituminous coal is cut o and t e pulverized cuhn is substituted therefor. The regular operation then proceeds continuously. The mixture of air and pulverized culm projected into the combustion chamber through the pipe b draws in an additional supply of-air through the conduit c and'is at;

1n proximity to the entra nce conduit for the l lfuel cloud, and the said exit port leads into P As soon as the c-omonce ignited by thc heat radiated upon :'i from the ignition wall or arch n. 'l`hc 'if l nih-d fuel cloud traveling rapidly aloof;- the wall or arch n constitutes the enrwucc of the loop is thus radiated, as the opera! im proceeds. u on the entering branch of th.`

and ignited fuel cloud o ai arl pulrcri/.cd culm.

A portion of the products` of f'oxuhnstifaom the Home cloud is drawn into the entr-r i 'jg fuel cloud at the point where the latter issues from the injector into the combustion chamber. thereby impartin; r to th.` fue! cloud the sensible heat of thc portion of t'ac products of combustion thus 'cntraincd Fuimident with the intense infialning of them.'-A turn hond or current of the loop, the aecour have experienced an enormous erpansiou.v -o that the flame cloud rises through the up take in strong volume and with a velocity which is greatest at. the middle of the arch a.

i preferable point of location for the fuel ini jcctor, although Iitu-ill he understlmd that l do not limitmyself to such location` as in some instances. especially, for large furl naces, it may be fpund desirable to use more i than one fuel in]cetor. Finally, the main body portion of the products of combustion, l issuing and passing along the idc und soaclous tine e on the reverse sido ot' the highly Il conducting thin `wall or arch a ltccps said I wall or arch continuously at the high tcmperaturc newssary for thc maintenaluc of i ignition of the entering cloud of air and l pnlvcrizcd culm. l'tftersnbservingthc functions described, the'products of combustion i'pass on to the place of use for which they are intended, as, for instance. to a steam iii-Inch of the loop. The ignition prog'wfl-c the flame cloud constitutingvthc return bend loop consiscang ot` the continuously supplied panying air and products of combustion Accordingly l have selected this point as the.

lltl

i boiler, a kiln, the lai-oratory of a metallurl i git-.al or heating furnace, or the like. g While I have described in detail the specitic application of my invention to the l waste material known' as anthracitel cuhn` l yet, it will be quite evident that the method l described is equally appli 'able to other fuels lof diflicult ignitibility which are usually, for this very reason, regarded as waste fuels. and exist at. present, in enormous quant itu-s. Such materials form at, the present time a large item in the waste of our natural resources, and their etlicient, utilization is o' ..t 1.1 15mm-..4

cat economic and national importanrv.

mong such materials l would enumerate coke breeze, charcoal breeze. tank mud from coal Washeries` and low grade bituminous dusts of difficult ignitihility, containing high percentages of ash. Furthermore. it is quite within the range of practicability to pulverize the smaller .sizes of antl aeite Coal and burn them as dust hy my invent-ion. l wish, therefore. to include artiticiallv powdered anthracite with the anthracite onlin. as within the scope of my invention.

Havingr thus described my invention. what l' claim is:-

1. The method of burningT anthraciteculm and similar materials. which Consists in raising the temperature of a combustion chatnlie-rv up to the ignition point of a hotly 'of air mixed with Asuch material in powdered forni, projecting the mixture into, and along a wall of. the eomhustion chamber and ignitingz it therein. causing the products of eomf and similar materials, which consist.: in projecting into a combustion chamber and aloruv a wall thereof a body of'air mixed with such material in powdered form, preheating said wall up to the ignition temperature of said mixture. whereby` as the incoming?Y current.

enters. it will be ignited, causing the. prod` nets. of combustion to return upon themselves within the combustion chamber. the return current radiatinf: heat upon the iiicoming current. entiaining into the inconifeomhustion chamber; substantially as de scribed.

4. The method of burning anthraate euhu and similar materials. which ronsists in rojerting: into a romhustionehamher and a ong,l

r a wall thereof a hotly of air mixed with such and causing the products of eomhustioiu after takin; their exit from the conduis-'tion elnunla-r. to maintain said wall at an ignition temperature at4 the point of discharge g selves within the combustion chamber, the

of tlu fut-l: substantially as doaerilied.

The method of burningr anthraeiteeulm and Similar materials. wlueh 'consists in pronuiterial in powdered form. preheating .said wall up to the ignition temperature of said mixture, whereby as the incoming current enters it will he ignited. causing the products of combustion to return upon themreturn current radiating heat upon 'the ini coming current, entrainxng into the incomjevting into a combustion chamber and alongr 5 a highly heated ignition .surface thereof a ,i hotly of air nuxed with such material in I powdered forni. thereby igniting the mix- I ture, causing the product" of combustion to return upon themselves within the combustion elsambt-r. iluI return current radiating:

its heat upon une side of the incoming curi rent. and t'nrtlu-r heating the incoming.: current so as to asas! in its detlagration hy I musing the produtts of combustion after they leave the combustion chamber to pars along thc reverse side of thc highly heated ignition surface and maintaining:r said surface tlu-reliy at an ignition temperature at the point of discharge of the fuel; 4substantiallj, as described.

3. The method "t burning anthraeitecnlm ing current a portion of the products of combustion from the return current. prelieating the incoming mixture of air and fuel powder by heat from thc outgoing products of conihuslion. and continuousl)l maintaining the preheated wall at the point of discharge of the fuel atthe ignition temperature for-ilux mixture b v passing the outgoing produvts of combustion along its reverse side after they leave the cnnbust ion chamber: substan tially as described.

In testimon whereof I ax my signature. in presence o two witnesses.

HENRY R. BARNlIliltS'l.

Witnesses:

Summer Il. KING. Raynox!) \l I ns'rz.

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