US1587197A - Joint working of flames and arcs and apparatus therefor - Google Patents

Description

June 1 1926.

(5. T. SQUTHGATE JOINT WORKING OF FLAMES AND ARCS AND APPARATUS THEREFOR Filed Mayz'7- 1924 June 1 192% 1,587,197

e. T. SOUTHGATE JOINT WORKING OF FLAMES AND ARCS AND APPARATUS THEREFOR Filed May '7, 1924 3 Sheets-Sheet 2 June 1 1926.

1 587 19? T. souTHGATg JOINT WORKING OF FLAMES AND ARCS AND APPARATUS THEREFOR Filed May 7, 1924 g f I a I l l I i u i s Q I i 9 L.

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Invenmn liatented June 1, 7 1926.

warren STATES GEORGE THOMPSON SOUTHGATE, OF ANNISTON, ALABAMA.

some woanrns or names AND anus AND srrnna'rus mnnnron.

Application filed May F,

The invention relates to the joint use of combustion flames and electric energy in thermal, thermo-chemical and electrochemical effects and particularly to an improved process and apparatus for producing combustion flames having electric arcs extending along the same.

It has already been proposed to arrange a pair of electrodes with their" arcing tips disposed in front of a flame projecting nozzle, the arcing tips being spaced trans versely of the flame stream and'the are being elongated into U-shape by the blast, and it has been proposed to use combined electrode and nozzle structures for the formation of arcs along the flame stream, the arrangements being such that the arcs spring from the nozzle or from a point so near the nozzle that the arc could strike back thereto.

The present invention relates to the for mation of arcs extending along, as distinguished from across, flamestreams,,the apparatus and process being such that the arcs are spaced from the nozzle structure and cannot strike back thereto. The apparatus is characterized by the rovisioni of flame-projecting nozzles and rigid electrodeshaving their arcing ends spaced from the nozzles. The electrode tips are positioned in or closely adjacent to the combustion flames, and the electrodes may extend through the nozzles or they may lie outside the same and pass obliquely into or to points adjacent the combustion .flames. In working with such apparatus under my novel process, the [supplied fuel and air are projected from the nozzles at such velocity 'that the arcs cannot strike back to the nozzles. A

The invention permits the use of relatively large bodies of combustion flame with much smaller proportions of heat from electric energy. The combustion flames may be reducing, neutral or oxidizing, and the current source may be either direct or alternating, but is usually of relatively high voltage. In the accompanying drawings Fig. 1 is a longitudinal'midsection and Fig. 2 is a cross section in the plane 2-2 of: a typical nozzle-electrode constituting one form of my improved apparatus;

Fig. 3 illustrates a preferred manner of 1924. Serial No. 711,615.

leading water to and from the nozzle or any other part of the apparatus which it may be desired to cool with water;

Fig. 4 IS a lan of three of the improved nozzle-electr es in one of the hrrangements sultable for three-phase operation in a closed chamber;

Fig. 5 is a plan of two nozzle-electrodes su tably arranged for operation from different types of electricity supply and showingv the connections made to the nozzle-electrodes and to the objective-upon which the fuel electric flames impin e;

F gs. 6, 7 and 8 show t e invention embodied in a furnace for smeltin or melting operations; Fig. 6' being part y an elevation and partly a vertical midsection, Fig. 7 a vertical section in the lane 7-7, and Egg 8 a plan section in the irregular planes to the outlet end of the nozzle for a mix ture thereat, but a simpler arrangement is obtained by introducin the fuel and air together at the rear en of the nozzle bore 14c. A if-inlet 14 cooperates with the bore 14 to form a blowpipe Which is supplied with fuel through the pipe 15 and fuel valve 16, which parts are separated from i the blowpipe inlet by a hollow electric insulator 17 The pipe 15 is fed from a main 18 which may be the usual pressure header when a liquid or gaseous fuel is used. With powdered fuel, the main 18 should be provided with means, such as a revolving screw, for insuring a ready feed into the inlet 14*. The air or other oxidizing gas is led to the blowpipe by way of pipe 19, valve 20 and electric insulator 21, the supply being from pressure main 22. An electric terminal 23 and lead wire 24; connect the nozzle to a suitable source of electromotive force. i

Within the bore 14 of each nozzle 11 is ice res

arranged an electrode 525 may Q i I 145 3749? a fluid-eboledmetal'Qtube having a renewable arcing'tipQ By providing thesolidrods or packed tubes withthreaded ends 2.6, new

forward fandcom'- letely consumed. To insure good electr cal contact between the electrode "and the nozzle as well as to prevent inadvertent-movement of the electrode, the

nozzleis provided with-fa slip tube 27; of

such dimension'sasto fit the electrode rather snugly. when the a paratus is used in a furnace workingun er a pressure higher than atmospheric, the outer end of theslip tube is provided withj-a paclfing gland 28. The slip-tube is preferably extendedzbeyond' the-nozzle 11b a refractoryportionfl29 which" protects t e electrode against; exces sive oxidation b flame 12. i

.''-For the supp y"; f?

whereby water=isdelivered th ;.to' andfrom the nozzle in, broken nection the .water supply system and' the and between" the nozzle and the nozzle-electro es.

hjch the noz'z e 33 capable of,

ate the The sprayed water falls into funnel -35wand i is carriedgto nozzlell bypipe" 3& From nozzle 11 the spent 'water issimilarly'discharged to the drainage system'via pipe 37,-nozzle 3-8, spray 39, funnel 40,-pipe'41f. and-drain header 42.

In furnace structures, each of the nozzles is electrically insulatedfrom, the structure and Supported by aninsula'tor43 of thermally refractory material which maybe buil't'directly into the masonry of the furnace. -The' bores of the insulators are fluted with alternating channels 44 and ridges 44, which ridges bear a ainst and firmly support the The i-nsulatorsprefcrably extend within the-furnace 'to the ends rotect the latter from by radiation from the furnace interior, w 'ich' extended length also insures superior electrical insulation by. providing agreater length of electrical creepage sur- "face.

The outer ends of the nozzle-electrode assembly are enclosed by a wind box 45 which .is supplied, by air pipe 45*, with air from a suitable source, such as a centrifugal fan or arotary blower. From wind box 45, air

- passes to the. furnace through the channels 44 as a'supply of secondary air for insuring .through the nozzle with the primary air a for the burning of unoxidized gases 'evol'eii within the furnace. This secondary jiftai" p supply cools the nozzles and the wind box sections may be attached at the outer ends of theelectrodes, the stumps be ng pushed 45'insures the safety of the operators by "enclosing the electrically live parts. A su1t-.

able sight window 46 is provided, preferabl inthe hinged cover 47 of the-box. Door 4 preferably operates a contact 48 in circuit with a relay upon the main switch, the

that the electric parts within the wind box are pot alive when -the relay circuit isbroken. When the door 47 is open the relay operator{ and to the apparatus, the wind cooling .wate'rtofthe box 45,?air duct 45f=and conduit 48 should gaseous or powdered fuel is used." The -s'trictured orifice 49 is preferably -formed by -'mounting a bushing 50 over the slip tube 27 fits junction with the refractory extension 1.29, which bushing may act as the coupling ;u .the-disch'argedwater into a sprayifi of Small-drops; Valve 32 is i pipe 31* and used to re supply-1'- ofwater discharged in t e spray.

between the slip-tube and the extension. The bushing-'50 is centered in the nozzle '11 by narrow, low ridges 51. Liquid fuel, for

. -power and relay circuits being so arranged example oil, enters the Y-i-nlet 14 from fuel pipe 15 and is entrained in and mixed with the primary air as it flows through the nozzle bore -14, being atomized or finely sprayed therefrom and into the combustion flame as it passes through the strictured orifice 49. Figs, 6, 7 and 8 show-a furnace comprising a stack 52 and hearth 53, which furnace is one "of the several types in which the invention-may be employed. Stock 54 isfed down the shaft, preheated and melted therein, and further melted in the hearth where i the 'final physical and chemical transforma tions take place. 'The hearth is provided with'a'tap hole 55 and with a peep-hole 56. By providing ample space for the combustion' offuelthe dimensions are suitable for the projection of relatively long arcs 57 and commercial line voltages may be employed.

.In practical operations I have employed electromotive' forces ranging from (300 to 6000 volts and both alternating and direct currents have been successfully used.

As shown in'Figs. 4 and 6, the electric arcs need not reach the furnace stock but may mutually join, each other and play in the space above therbat h. With threephase alternating current anassembly of three nozzle-electrodes is used, .each'leg of the supply circuit being connected to an individual nozzle. While no neutral connection is reuired, if one is available it may be made to t e bath in the usual manner.

The supply connections shown in Figxb are alternative, that is, any one of the six illustrated supplies may be used. The systern of supply shown diagrammatically at the top of the diagram is a three-phase supply 58, delta-connected with the t ird point of the delta connected to the crotch or impingement point of the arcs, which connection may be effected through the stock or work 59 upon which the flame-arc is I rojected, The supply 60 is a quarter-puse alternating current with a neutral connection. The supplies $1 and 62 are three and systems, and the supplies 63 and M areglre two wire, respectively, direct current supply spectively, three and two wire, single-p ase alternating current systems. The are may be formed in space or the crotch oil the are may impinge upon an objective, such as the charge in the stack 52, which ob ect1ve may be connected to the neutral 0:? a threewire direct or alternating current circuit.

To put the apparatus in o oration the electrode tips are arranged wel beyond the ends of the nozzles and fuel and air are ad- Kill mitted to the nozzle bores, the combustion flame being i ited by any suitable means and the supp y valves ad usted to give a fairly still blast flame burning around and beyond the electrode tips. Upon closing the main switch electric arcs will play from the end of each electrode in and along the respective combustion flame to their junction or to the common objective upon which they impinge. The velocity at which the fuel mixture is projected should be such that the arcs'cannot strike back along the flames and into contact with permanent parts of the inn stallation.

in operating my improved process in a hearth furnace ll discovered that there is a great acceleration of the fuel combustion itself because ct the'pronounc'ed ignition effeet of the intense electric arcs. The discovery was made when it was observed that the and air supply, signifies more rapid and consefluently hotter combustion. That this was in eed the case was clearly indicated by the greater brilliance of. the combustion tlanies "even much beyond the lengths of the area.

The are operation is satisfactory whether the combustion flame be reducing, neutral,

or oxidizing, but with an oxidizing flame electrodes of metal tubes packed with carbonaceous matter are superior to naked carbon or graphite rods as they resist oxidation better. As the electrodes burn back by are consumption the regulationot current magnitude is obtained by advancing the rods either by hand or by suitable electromag netic mechanism. I

It is usually preferable to supply the greater part of the energy by fuel and to use only such smaller portion of electrical energy as is required to give the desired increase of the joint temperature by the on ceedingly high temperature of the arc. The invention permits the use ofany ratio of electric to liuel energy and with perfectly stable operation. With furnaces containing relatively large burdens such that considerable storage of high-intensity heat is practicable, electricity may be used only intermittently during periods of the day when electricity may be purchasedcheaply, yet it may be used effectively in maintaining high average temperature and productivity by intermittent increments of intense super heating. i

The process may be used in connection with the gas, oil or powdered fuel burners commonly employed under steam boilers, resulting in big or temperaturesand particularly in more stable operation when lowgrade or refractory tuel is employed. in this and otherv applications of the invention the electrodes need not extend through the nozzles but may pass obliquely into the corn bustion flame somewhat beyond the end of the nozzle. With a single fuel nozzle and flame, two electrodes are used with their arcing portions in contact with the flame, one nearer to and the other farther from the nozzle.

Substances to be subjected to the'intense heat of the flame arcs may be introduced throue'hthe nozzles in gaseous, liquid or granulated form, or they may be agglomer ated into the electrodes. lll hen high voltage direct currents are employed, advantage may be taken of electrolytic effects in the arcs. The introduction into the flame of the vapors of certain substances increases the electric conductivity and improves the steady arcing action oil the flames. Granular substances containing moisture or gases in unstable ccndition are disrupted into much finer condition when introduced into the flames. For

example, iinely powdered quiclrlime is ob I teined when granular limestone is passed 1 1 through the nozzle and into the combustion flame.

l t is obvious that thesteps of the proc void 4 as well as the arrengement of the apparatus -may be varied without departing {from the spirit of my invention,

The nozzles may be formed or": refractory material other than metal and ordinarily fluid cooling of the nozzle is not necessary 7 wt... a liquid fuel is employed. The sup-1 porting blocks 43,-niaybe of metal, suitable insulation being providedwhen. both; the blocks and nozzles are metallic. 1A single block maybe provided with a plurality of cl'iannelsfor receiving the plurality of noz- 'zles of a single assembly.

In place of forming the are within and" along the flame it may be directed along and close to the. flame by a blastof air or other ga-s. On the other hand, a particularly thorough intimacy between the combustion flames and the electrodes may be obtained a ,by the use of a bundle of small rods in place 99 or more of the nozzle'elec'trodes of an assem- 1blymay be pivotally supported for varying i the angle of convergence between the electrodes. These and many other modifica- ",ftions fall within the scope of the" invention.

f Vhile the invention has-beenshown f'rlescribed as embodied in a furnace struc :ture, it will'beapparent that the novel procama apparatus-may be employedin'the an ting, welding or other local heating of 9 metals-or other solids.

; I claim: 4 1. In heating'by a combustion flame and an electric arc superposed on and extending longitudinally of the flame, the process whichconsistsin establishing -the'-stream of prises establishing a stream of flame and an and-in'directing the arcjto and along the fflame stream by a gaseous blast- Which is passed over the arcin g'- .portionof the elec-- .14 a v 2. In the process ofjheating by a combusjtion flame and a superposed arc originating atv a source spaced .from the source of a.

trode.

stream. of flame, the step which comprises directing the are to and. along the-flame .stream by a blast passing over the arc s ourceat suchveloc'itythat the arc cannot strike" back to the blast-producing nozzle. a

3.'In heating by the joint working of combustion flames and electric ares, theprocess which consists. in projectinga blast of oxidizing-gas mixed with fuel from a nozzle and lgnlting the same 'to 'establlsh-a stream of flame, forming an are between portions of rigid electrodes spaced from said nozzle and at different points along the stream of flame, and maintaining the velooityof the fuel mix: ture such that the arc cannot strike back to the nozzle' 4. The process of heating mobile sub-- stances at'high temperatures which comare from independent sources, directing said are upon and along said stream offlame by a gaseous .blast, andblowing into 'said flame stream the. mobile substances to be .heated. 5. The process of electrolytically treatmg mobile substances at high teniperatures,

flame, uperposing upon said stream of flame a direct current are established'between' elecftrodes having their arcing portions located at different points along the flame stream and spaced from the source therepf, and 1ntroducing said mobile substances into said flame stream by a" gaseous blast.

prises incorporating said substances in electrodes, establishing a stream of flame, draw- ;ing auarc from an electrode which includes tlie'substance to ,be heated, and directing a gaseous blast.

7. .The invention as claimed in claim 6,

- which" comprises: establishing a ,stream of.

eoi

saidarc to and along said stream of flame by wherein the electricsupply tosaid are is "direct current, whereby'the substances-may be subjected to electrolytic treatment.

1- 8.1a apparatus forheating by the joint use of an electric arcand "a combustion the arcing portion. ofsaid electrode and alongthe. stream of flame, and means for the arc cannoti strike back to said nozzle.

' 9. Apparatusfor heating by superposing an-el'ectricarc upon and along acombustion flame and the are. from independent sources,

' tionbeingso spaced from the nozzle that the gaseous blastif'prevents the. are from striking back to the nozzle. 4

combination with a nozzle for projecting a stream "of-flame, ofa{'plurality of electrodes having the arcing portions thereof spaced l1.- In apparatus for. combustive and electric'he'ating, a nozzle-electrode comprising a nozzle having a bore therethroughfor projecting .fuel and oxidizing matter into a stream of flame, and an electrode coaxial with said bore and having an flame, means for superposing an arc and alonga stream of flame comprising an electrode, a nozzle for directing a blast overt 10. In apparatus gfor' heatinglfby' super- .posing an electric; fupon-af fla'me the 6 fromsa'id nozzle and. at"difl'erent, distances "therefrom.,

arcing portion projecting beyond said nozzle.

.:- '12. In apparatusfor c'bmbined combus tive and electric heating, a nozzle-electrode comprising a nozzlehaving abore .there through, a tube within said bore, a-rigid electrode slidable through said tube and having an arcing portion projecting beyond said nozzle,-anda refractory sleeve project- "ing beyond said tube for protecting the'electrode from oxidation,

' 13. In apparatus for combined combustive and electric heating, the combination with a plurality of nozzles arranged with their bores directed toward the space to be heated, of meansfor projectin combustible matter and an oxidizing was rom said bores, andrigid electrodes having arcing portions spaced from said nozzles. p

14.- Apparatus according to claim 13, wherein the nozzles are so directed that their flames meet each other in space, whereby their arcs also are made to meet each other-in space. 1 r V 15. Apparatus according to claim 13, combined with means for sup lying secondary air around the nozzles an into the combustion space.

16. Heating apparatus comprising a .noz-

zle for progecting a fuel mlxtu're into a. ame, a thermally refractory stream of bushing surrounding said nozzle and having its walls spaced therefrom to permit the introduction of secondary air, and means comprising a rigid. electrode having an arcing portion spaced from said nozzle for superposing an are upon and along the flame stream.

'17. In a furnace, the combination of a plurality of thermally refractory bushings their bores substantially integral electrodes projecting beyond .the ends of said nozzles,

of means for roducing combustion flames from said nozz es and surrounding said electrodes, and means for supplying electricity of suitable electromotiy'e force to said electrodes to cause electric arc conduction in said flames.

In testimony whereof I afiix my signature.

GEORGE YT. SOUTHGATE.

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