Symmes, E. M.

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 The Knowledge Bank at The Ohio State University Ohio State Engineer   Title:  The Manufacture of Dynamite and Gelatin Creators:  Symmes, E. M. Issue Date:  Mar-1921 Publisher:  Ohio State University, College of Engineering Citation:  Ohio State Engineer, vol. 4, no. 3 (March, 1921), 17-19, 24. URI:  http://hdl.handle.net/1811/34083  Appears in Collections: Ohio State Engineer: Volume 4, no. 3 (March, 1921)   The Ohio State Engineer 17The Manufacture of Dynamite and GelatinBy E. M. SYMMESDynamite is unique in not having been inventedby the Chinese or mentioned by Shakespeare. Itwas first introduced by Nobel, the Swedish engi-neer, in 1866, after numerous accidents hadresulted from the use of nitroglycerin alone. Mr.Nobel discovered that by mixing nitroglycerinwith kieselguhr, an absorbent earth, it becamesafe to handle, and its explosive power was notseriously reduced. Modern practice has elimi-nated kieselguhr in spite of statements to the con-trary in nearly every text book on the subject andsubstituted an absorbent composed of nitrate ofsoda, nitrate of ammonia, wood pulp, flour, etc.,which give an active dope, that is. one that willassist in the explosion instead of acting as an ab-sorbent only, as is the case with kieselguhr.The method of manufacture and preparationof the various ingredients will be consideredbriefly before discussing the actual making ofdynamite according to the process employed bythe Hercules Powder Company.The Nitrator Tank on the Right Contains Mixed Acid intoWhich Glycerin is Fed from the Scale Pot on the Left, andthe Mixture Agitated by Power from the Small Engine inthe CenterNitroglycerin is made by adding slowly to amixture of strong nitric and sulphuric acids acomparatively pure glycerin, agitating the mix-ture meanwhile by large, mechanically drivenpaddles and removing the heat by coils throughwhich cold brine is circulated. A modern nitra-tor produces about 3,000 pounds of nitroglycerinat one operation, consuming 7,000 pounds ofmixed acids and about 1,200 pounds of glycerin.After all the glycerin has been slowly added to thenitrator, which consists merely of a steel tankwith the brine coils around its outer edge, themixture is let down into a lead tank and allowedto stand until the nitroglycerin rises to the topand the acid falls to the bottom. The top layerof nitroglycerin is then drawn off and deliveredto a tank of warm water, where it is washed freefrom acid by agitation with compressed air. Theacid left from this operation is treated at the acidrecoveries to regain the nitric and sulphuric acidscontained in it. The nitroglycerin is then givena final wash with soda ash solution to remove thelast traces of acid, as acid nitroglycerin cannotbe kept any length of time without serious decom-position, with possible danger of explosion.The Mixture is Allowed to Stand in this Separator Until theNitroglycerin Rises to the TopThe absorbent material known as dope is pre-pared by mixing and screening proper propor-tions of dry and ground nitrate of soda, nitrateof ammonia, wood pulp, flour, starch, sulphur,chalk, etc., and is taken in fibre barrels to themixing house and put into a dynamite mixing ma-chine, an illustration of which accompanies thisarticle. Nitroglycerin,' after preparation andtreatment as outlined above, is taken by means ofthe copper-lined, rubber-tired buggies (see illus-tration) to the mixing house and is added to thedope. This mixing machine consists of a woodenbowl with large wooden wheels running in it.These wheels are edged with ebonite, or hard rub-ber, thus allowing no metal actually in contactRubber-Lined Gutters in Which the NitroglycerinFlows to the Storehouse18 The Ohio State Engineerwith the dynamite while being mixed. The driv-ing of these machines is done with large overheadpulleys made of wood, which obviate any possi-bility of rubbing metal, thereby producing sparks.Five minutes' kneeding under the wheels of themixer suffices in most cases properly to incorpo-rate the nitroglycerin throughout the mass ofdope-The Nitroglycerin is Washed in these Lead Tanks and byNeutralization the Last Traces of Acid Are RemovedThis material, which is now loose dynamite, isremoved from the machine by wooden shovels andput into wooden tubs, which are used to transportit to the Hall machines, where it is packed intoparaffined paper shells by- the action of woodentamps, tipped with rubber. These shells aremade by a machine which takes roll paper of fromRubber-Tired Buggies Are Used to Convey the Nitroglycerinfrom the Storehouse to the Mixer18 to 24 inches wide, cuts, prints, and crimps oneend, and discharges into the collector, as shownin the illustration, at the rate of from 180 to 200per minute. They are packed loosely into cratesand taken by a traveling chain through a cham-ber, where they are sprayed with hot paraffin toimpregnate the paper and prevent absorption ofthe nitroglycerin. They are then delivered bytram truck to the Hall or the gelatin machines.These Hall machines mentioned above are verynearly automatic and it is only necessary to main-tain a supply of loose powder and sufficient shellsThe Nitroglycerin and Dry Dope Are Incorporated by aMixer—Heavy Rubber-Tired Wheels Revolve in a WoodenBowl Which Contains the Ingredientsin order to perform the complete operation offilling the cartridges to the required amount,crimping the top, and laying them out on a table.They pack at each revolution either 25 or 30 cart-ridges and have a capacity of approximately30,000 pounds every eight hours. This is a greatimprovement over the old days when each shellwas filled through a funnel by hand operation,requiring every stick to be handled several times.These cartridges of dynamite are then carried inwooden tubs to the packing house, a view of whichaccompanies this article, where they are sealedso that th dynamite cannot absorb moisture bybeing dipped for an instant in molten paraffin.They are then placed in paraffin-paper lined boxes,containing a small amount of sawdust for a cush-ion, are weighed, and nailed up by an automaticnailing machine which completely fastens thecover in two operations. From there the boxesPaper Cartridges Are Printed and Rolled by a Shell MachinePrior to Being Loaded with Loose Dynamite or GelatinThe Ohio State Engineer 19The Empty Shells Are Automatically Sprayed with MeltedPanffin to Render Them Waterproofof powder are taken to the magazine, which ismerely an unheated, barricaded storehouse situ-ated on a broad-gauge spur for convenience inshipping. This completes the manufacture ofdynamite.Since dynamite does not withstand the actionof water very well, it was long ago discovered thatthe addition of small amounts of nitro cotton tothe mixture of nitroglycerin with various absorb-ents produced a material somewhat similar tojelly- This material resists the action of waterexceedingly well and is known as gelatin dyna-mite. Due to its nature, gelatin manufacture hasto be carried on differently from that of dynamite.The nitroglycerin and dopes, prepared as outlinedabove, are taken to a gelatin mixing machinewhich consists of a bronze bowl surrounded by alead jacket containing warm water and twobronze paddles used for kneading the dough-likemixture. These hold from 500 to 600 pounds ofthe gelatin for each charge. The mixed gelatinlooks very much like ordinary dough made fromwar flour, although the taste may be somewhatdifferent. This is shoveled out into wooden boxesby the wooden scoops, an illustration of which isshown herewith, and taken to a machine which bythe action of a worm forces this material throughnipples into paraffin-paper shells placed directlyunderneath. This is known as the gelatin ma-chine or Schrader and is necessary because sucha sticky mixture as gelatin cannot be handledNitroglycerin Is Incorporated with a Special Dope in aDifferent Type of Mixer to Make Gelatinthrough the Hall machines mentioned above. Therest of the operation of gelatin manufacture, con-sisting of packing in boxes and storage in maga-zines, is exactly the same as that of dynamite.The manufacture of dynamite or gelatin may seemlike a very simple process, but very close atten-tion is necessary at every stage. The amount ofThe Filled Cartridges Are Placed in Wooden Boxes Linedwith Paraffin Paper at the Box Packing HouseA Typical View of a Dynamite Line—The Building in theBackground Is a Mixing House—Note the Barricademoisture in the finished product must be held ata minimum, due to the serious effect water hason the ageing and strength of dynamite andgelatin.The manufacture of nitroglycerin requires theclosest supervision, not only from the standpointof danger but also to obtain the best results possi-(Continued on page 24)04 The Ohio State EngineerTHE MANUFACTURE OF DYNAMITEAND GELATIN(Continued from page 19)ble. The fineness of the nitrate of ammonia andnitrate of soda used in the dope is an importantfactor, and also requires close supervision. Thepressure of the tamps in the Hall machines de-termines the density of the finished dynamiteand also determines the number of sticks that a50-pound box will contain. All dynamite andgelatin is tested before shipment by obtainingsamples daily, and analyzing these to determinethe degree of accuracy with which the ingredientshave been employed.

The Manufacture of Dynamite and Gelatin

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The Manufacture of Dynamite and Gelatin

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