US1262546A - Furnace for burning pulverized fuel. - Google Patents

Description

Patented Apr. 9, 1918. I 2 SHEETS-SHEET I.

J. E. MUHLFELD. FURNACE FOR BURNING PULVERIZED FUEL.

APPLICATION FILED DEC. 2. 1913.

WITNESS S J. E. MUHLF ELD. FURNACE FOR BURNING PULVERIZED FUELQ APPLICATION FILED DEC- 2, '93 1,262,546., Patented Apr. 9,1918.

I 2 SHEETS-SHEET 2 wrmzss s ina-ry sore? E. @1 SGABSDALE, NEW YGBK, ASSIG-NQR tilt) LGOEEGTEVE EULVEBEZED FUEL CQMPANY, A CORPQRATION @175 IBELAWVAEE,

FU'Eblilfifil FOB BURNING PULVERIZ'ED ZFYUIEL.

recast-c,

Specification of letters Patent.

Patented Apr, 29,

Application filled EBecember 2, 1913. Serial No. 804,192.

To all whom it may conceive:

Be it known that 1, Joan lvlonnrnnn, of Scarsdale, in the county of Westchester and S'tete of New York, have invented a certain new and useful Improvement in Furnaces for Burning Pulveriaed Fuel, of which improvement the tollovving is a specification.

My invention, relates more particularly to means for burning combustible matter in a comminuted or finely pulverized state, in the fireboxes or steam boilers, particularly locomotive boilers, and in connection vvit' heating furnaces out other descriptions, and its object is to rovide means which shall be readily and inexpensively applicable in connection with furnaces or fireboxes of the ordinary construction, for supplying fuel of such character and air, in proper proportions, to a furnace, and enabling its thorough and efi'ective combustion to be carried on therein. I

To this end, my invention, generally stated, consists in the combination, With a main orlfinal furnace chamber, of a prelimiurnace chamber, located vexterior and adjacent to the final furnace chamber and communicating therewith, and constituting a preliminary fuel treatment space, in which the fuel is commingled with air and gasified or partially consumed prior to its complete combustion in the final furnace chamber.

The improvement claimed is hereinafter fully set forth.

In the accompanyln dravvincs: Figure l is a vertical .longitu inal central section through a locomotive boiler firebox, illustrating an application of invention; Fig. 2, a horizontal section through the preliminaryfurncce chamber, on the line a o of Fig. 1; Fig. 1%, a section, taken similarly to Fin. 1, illustrating a structural modifica-= tion; big. 4:, a nertial horizontal section, on the line b b of Fig, 3; and, 5, a section, taken similarly to Figs it and 3, illustrating another structural modification.

Referring first to'l igs. 1 and :2, my invention is exemplified as applied in connection with a main or final furnace chamber, which is shown as a locomotive boiler firebox of one of the present standard types, and is indicated, as an entiretby the symbol A, from which c' amber the products or a plate or plates,

combustion of fuel burned therein are'conveyed through a plurality of fire tubes, B, in the Waist, C, of the boiler, to a smoke box and stack, (not shown) at its opposite end, in the ordinary manner, in which the parts enumerated cooperate to produce a draft'in the firebox. I

In the practice of my invention, l provide, at the bottom of the firebox, afloor, l, of brick or other suitable refractory material, the ordinary rates and ash pan which are used for burnmg solid fuel not being necessary or applicable. The floor may be located at any desired level, relatively to the bottom of the firebox, as may be best suited to the depth of the latter, being herein shown as set some distance belovv the mud ring, a, upwardly extending side and end Walls, 1, of. fire brick, forming a closure for the intervening space. lln fircbores of greater depth it may lie in or near the plane of the bottom of the mud rin A preliminary chamber, 2, of tire brick or other suitable refractory material, props erly supported exterior and adjacent to the final furnace chamber or'firebon, A, being, in this instance, located below the mud ring, and extending rearwardly and horizontally from the back head of the boiler, The "form, in transverse section, of the preliminary chamber, is not an essential of my invention,

and it may be or" rectangular, circular or elliptical transverse section, as preferred, bein in this particular instance, variable within the discretion of the constructor, or as may be best suited to acconnnodate ad3a= cent members of the vlocomotive on which it is installed; The preliminary chamber "is open at its front end to the firebox, belowthe mud ring, either partially, as shown, or throughout its full Width. 7

Bodies or columns of pulverized fuel are delivered into the rear end of the prelim inary chamber, 52, either by being forced thereinto bya tan or pressure blower, .orby

being drawn thereirto' by induced draft,

through one or more conduits, 23, any desired number of which may be applied, and one being shown in Fig. 2. The conduit or conduits, 3, is orare passed through an o ening or openings, 3, which may be close by 8?, in the rear wall of preliminary chambers-and are adapted for till ice

the introduction at a proper volninc cc throughthe tire door opening,

with. the fuel. The top, side, and rearwalls of the preliminary chamber are covered by layers, 4, of a material which is a non-conductor ofheat, the non-conductingcovering 5 being inclose'd in a casing, '4 of sheet or plate metal.

A slag receptacle, 5, which is open at its top to the fire box, is suspended below the floor, 1, thereof, at its rear end, and is pro- '10 vided with an air inlet, 5, controlled by a door, 5 through which a regulated supply of. air ,may be admitted to the firebox.

In the operation of afurnace in connection with which a preliminary chamber substantiallyras, above described, is applied, the mix ture of pulverized fuel and air which is delivered, through the conduit, 8, to the preliminary chamber, 2, is commingled, in proper proportions, with air, ignited, and its preliminary combustion effected therein, it being partially consumed or gasified in said chamber, and the gaseous products of com bustion passing therefrom into the main or final furnace chamber, A, in which complete combustion is efiected. The preliminary chamber becomes highly heated, and the fuel and air supplied thereto are thor- \.ouglily commingled and preheated beforebeing completely consumed in the final furnace chamber.

The structural modification shown in Figs.

5? and r is more particularly designed for application in connection with deep and narrow fireboxes, and while according in operative principle with that first described,

difiers structurally therefrom, in the particular that the preliminary chamber, 2, is located above the level of the bottom of the final furnace chamber, A, and communicates therewith through the fire door opening, 5, through which the products of combustion are delivered into the final furnace chamber. Three fuel supply conduits, 3, are shownias leading into the preliminary cham- 4 her, their outlets converging in the\direc tion of the discharge opening, 6, thereof, but one or. a greater number may be applied as may be considered preferable under struc tural. and operative conditions,

Fig. 5 illustrates another structural modification innwhich two preliminary chambers, 2, and 2 applied in connection with the main or final furnace chamber, A, one of them,,2 being located above, and the other,

5 2, below, the firing deck of the locomotive, and being preferably, as shown, connected,

adjacentto the final furnace chamber, by a conduit, c, of refractory material, one or more of which may be used as desired. The to lower preliminary chamber is open at its front end-to theifinal furnace chamber, as inthe instance first described, and shown-in Figs. land 2, and the upper chambercomreunieates with the final furn ce-chamber naeaeee and 4. As in the preceding cases, any de sired number of fuel supply conduits may be @final furnace chamber or furnace proper in which complete combustion is effected, so is rendered available for the burning of the fuel and gases. A feature of special advantag is thataof economy of construction, as the preliminary chamber may be,applied,-

as a separate structure, in connection with existing furnaces, at materially less cost than that of reconstructing and enlarging the main furnace.

It will be observed that the preliminary chamber in the arrangement shown in the drawings has the fuel supplied thereto through a nozzle which directs the fuel to ward the opening between the preliminary chamber and the firebox, this belngthe pre ferred construction because the travel of the fuel carried along by the gaseous medium through said preliminary chamber may then enter the firebox without serious obstruction such as might precipitate some of the pulverized material. By making the preliminary chamber as shown of small crosssoctional capacity in relation to the size of the firebox or combustion space into which it opens, the flow through the preliminary chamber will be relatively more rapid help ing to hold the fuel in suspension and then when it reaches the larger area of the combustioh space or firebox its flow or velocity will be retarded so that the air supplied for final combustion will have better opportunity to become cdmmingled with the fuel and more complete cembustion andefticient operation will be obtained. The Velocity of flow through the preliminary chamber will vary, of course, with the dimensions of 11 the same so that ifit made of. substantially less cross-sectional area, it operate primarily as a mining or fuel treatment space for obtainin ther -such commingling of the air and fuel, latvinp the combustion to be accomplished in the firebox itself l claim as my inventicn and desire to secure by Letters Patent:

l. in an apparatus for feeding and burn- 125, ing pulverized fuel, the combination of a main furnace chamber, two preliminary treatment chambers located exteriorly of and adjacent to the furnace chamber and at ends we with said main furnace chamber, means for admitting a mixture of air and fuel to the rear ends of said preliminary treatment chambers, and a gas conduit connecting said preliminary treatment chambers at a point intermediate their res ective extremities.

2 In an apparatus or feeding and burning pulverized fuel, the combination of a main furnace chamber, a preliminary treatment chamber having communication at its forward end with the main furnace chamber, a plurality of openings at the rear end of said preliminary treatment chamber, means for supplying amixture of fuel and air under pressure through each of said openings, the currents of fuel and air being directed to converge and intermix at the point of communication between the said preliminary treatment chamber and the main furnace chamber.

3. A pulverized fuel burning apparatus comprising in combinationa means of relatively small capacity for introducing pulverized fuel, a preliminary expansion chamber into which thefuel is introduced, and which is provided with means for admitting air at the place where the fuel is admitted, and in which the fuel is preliminarily mixed and treated, said preliminary chamber being also provided wlth an outlet, and a relatively large combustion chamber into which the said outlet of the preliminary chamber opens, said combustion chamber being provided with a waste outlet in its bottom and with an exhaust means communicating with the upper part thereof.

l. A pulverized fuel comprising in combination a means of relatively small capacity for introducing a mixture of pulverized fuel and air, a preliminary expansion chamber into which the mixture of fuel and air is introduced and which is provided with means for admittin additional air at the lace where'the fue is admitted and in which the fuel is preliminarily mixed and treated, said preliminary cham ber being also provided with an outlet, and a-relatively large combustion chamber into burning apparatus which said outlet opens, said combustion chamber having means for admitting additional air therein, and a waste outlet at the bottom thereof and means communicating with the upper part of the chamber for inducing a draft therein.

5. In an apparatus for feeding and burning pulverized fuel in suspension, the combination with a firing chamber and means for inducing draft therein and a preliminary treatment chamber communicating with said firing chamber, of means for introducing a mixture of the fuel and a combustion supporting vehicle into said treatment chamber and for simultaneously inducing atmospheric air therein in volumes substantially proportionate to the quantities of the mixture delivered but insuflicient to effect complete combustion. and means whereby the draft in the firing chamber induces additional quantities of atmospheric air chamber, the point of inlet in the firing chamber being adjacent to the end of the preliminary chamber.

6. A pulverized fuel burning apparatus comprising the combination with a steam boiler, a firing chamber therefor having a waste outlet in the bottom and means forward of the chamber and communicating with the upper part thereof for creating a draft to draw the gases of combustion through the firing chamber, of a preliminary treatment chamber having an outlet opening into the firing chamber, means for introducing a mixture of fuel and air into said treatment chamber, an opening near the same whereby the fiow of an additional. supply of a combustion supporting medium is drawn into the preliminary treatment chamber and added to said mixture as it enters said chamber, but in quantities insufficient to effect complete combustion, and means for admitting an additional supply of air into the firing chamber.

JOHN E. MUHLFELD. Witnesses:

EMiLY L. MYERS, W. H. CoYLE.

into said firing

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