| Show DEATH MILL DUST TERRIBLE EXPLOSIVE FORCE OF FINELY FINE-LY GROUND GRAIN SolnIlO loploUon or S cli Accidents the Ulnopoll rlll iplmlon De Tlce to llctlurii tho IfenjCPF An InUr eUol In Ih Eoploloa Explosions of dust havo recently caused a number of severo accident One effect of thcso calamities has been to recall to observant minds the fact that many materials nro In puherized form explosives of exceedingly high power Not only coal ns i shown Infrequent In-frequent explosions In mines but tho povvder from grain saw dust nnd similar matcrinH has exploded with disastrous effect Thorough understanding of the subject sub-ject of dust explosion is I comparatively new Cass L Kcnnlcott ox city chemist chem-ist I of Chicago is an authority on tho phellomenon hnnu IrealClllt exhut ively in papers read before th i A aide my of Science und moro popularly inexpert in-expert testimony onco given bcforo a Jury Any explosion Mr Kcnmcott said U I a rapid combustion of u highly high-ly combustible material Tho explosIon of gunpowder for Instance Is I nothing moro than this Ibo consequent expand tug tendency is I so sudden that impeding imped-ing objects nre given a v lolent Impulse In u gun Ibo loud Is glcn n rapid start An nny explosion may bo called n rapid combustion ordinary combustion may on the other hand bo considered ns n slow explosion The chemical notion no-tion In tho two instances differs onlj In point of time In cither casu it is simply sim-ply a combination of tho combustiblo body with lea oxygen of tIle air Now it Is evident that In general tho rapidity of tho burning will uiercnso with the number of parts into which the combustible com-bustible U div Idod 1 A log placed upon n lira It burns moro or less slowly nu < I i i > < I I I c4 t 7d C 1 I 1 I JJ il a 1 i It twtaJ EtrEniMEXTAL DOST EXrlOSIOV ill nt length the constituents of tho wood hav a united with the oxygen of the air If tho log had been split into cord waecl the burning would havo token placo in a much shorter time If Ice cord wood wero split into kindling wood and piled so that tho air had free no cess tho burning would take placo still moro rapidly If the wood were ground into owdcrpowder so fine that It would float in Ice air combustion would take place fco rapidly ns to result In uu explosion So powerful is tho IlIj lluenco of the division that many sub stance which in bulk aro either relatively rela-tively uoncombustiblo or to bo ignited only with considerable < difficulty arc when in u fine stato of division readily ignltlblo As an example of a substance not combustible in tho ordinary scum of tho term iron may bo taken When finely divided either Into filings or by tho process of rustingit burns readily Simple as tho above explanation is I tho dust axplOl < lou phenomenon has been explained by a number of theories whoso falsity was equaled by their Ingenuity In-genuity Argument onco was advanced that tho explosion Is duo to coma form of spontaneoncombnsllon Otherhlvo endeavored to how that it resulted from a certain vibration of the dust particles afloat In tho air The fact is heat ihe 19uilion must com from ado ul light or a high degree of heat in some other form experiment has shown that other possible origins for the explosion explo-sion aro ont of tho question A delightfully interesting experiment with duet explosion is performed with a act of apparatus so simple ItA to hard ly deserve tho name comprising ns It does only a pair of bellows an alcohol alco-hol lamp or piece of candlo and a con plo of sticks fastened on edgo in tho form of a V Tor material fine flour will da Put a couple of tablospoonfuli or BO of llonr in tho point of the V whore Ibo two sido pieces thould be joined snugly Dy this arrangement n puff with tho bellows held at the open end of the V e will cause tho flour to fly up In n little cloud Before making this puff however light the candle or lamp Then push the bellows sharply and woof tho cloud of flour Instantly bursts Into a sheet of flame Tho flame goes out almost immediately im-mediately Essentially tho tome apparatus can bo applied In the construction of a box mad purposely for thehO experiments Tide V of sticks Is placed at the bottom of tho box as Is tho light The box is i fitted with n lid pushing tightly down over on upward extension which might bo termenl n chimney Tho lid being too to mON under prboure Is Ice port of tlio apparatus which is I to show tho fore of the explosion Tho chimney ij coiycntratlnR tho area of Ibo ixplohiou nlso concentrates foreo on the lid 1 Light lea lamp as before nod dls poso tha flour Put on tho upper fide of lea box hook It down aud jam the lid 1 down on to lIes chimney A pull with lIce Imllows Inserted at n small hole suitably sltnatul near the bottom of thee box blows up tho Hoar inside Tho ex plokion Immediately I following blows tho chimney lid suveral feet up in the air Using a small qupjitlty of lycopodinm pow del in place of flour Mr Keuukott shot tho lid weighing uo less than three pounds up to the level of the roof of a three story house Lycnpodium powder is nothing moo nor loam than tha pollen of n certain mots Its cfileucy in this experiment is duo to tho linoucu of its particles In more marked degree than at any recent disaster the power of oxplodiug dust was shown In the historic destruction destruc-tion of tho Wiithburu mills lu Mlmiu npollsMiiyi 1873 It is I recorded on n tablet on tho prevent mill that the explosion ex-plosion left no two stones of the original origi-nal btltictarn ntandiug one upon the other The pnoplo of Minneapolis at first mistook the explosion for an earthquake earth-quake Theos of sheet Iron loafing 8 by a fret were thrown twomllcl Eighteen lives vv ero lost nnd property destroyed to tho valno of over J800000 The generally accepted theory of tho canto of the explo lon is that Iho dnut In tho air local become Ignited by n spark from n lIry olonothat Is n pair at tnlllstones running without grain be twecn them an ocClllon1 oeenrrenc a In n flour mill Ibo stones become very hot under tho circumstances and knock parks from each other The explosion In the Northwestern elevator waa duo U was said at tho time to the Igniting of the grain dnst In tho air by the high temperature In lea drying shaft A number of iloviei to reduce tho danger from dust explosion hew boon tried with varying degrees of success In coal mining it onca was noticed that an explosion of lIce dmt eeccpao led lu tho air vv as especially liable to follow n blast necnml1len < lotion therefore vas made tlentqolobltloe bouneil Thiswhen wot would expand and rnek out pieces of coal without tho nso of flra Colliery explosions aro likely to bo particularly sovcro through union of lou cool dust With flro damp To make mill dust explosion prooi olso has been the aim of many eipi rl Kienti ions sometimes ttro used with ho Intent of blowing Iho particles V apart as to prevent them from Igult Mg from one Mother An ingenious de tico used In I somo sawmills is to blow Mhanst steam on to tho dust wetting t nnd making It settle Chicago Citncs Herald |
