US2577400A - Refractory lining for domestic furnaces - Google Patents

Description

Dec. 4, 1951 w. N. BUTTERWORTH REFRACTORY LINING FOR DOMESTIC FURNACES SHEETS-SHEET l Filed May 5, 1948 3rmentoi,

Will/am AZ 13 uzzer worfh, u

attorney Dec. 4, 1951 W. N. BUTTERWORTH REFRACTORY LINING FQR DOMESTIC FURNACES 2 SHEETSSHEET 2 Filed May 5, 1948 Gttomeg Patented Dec. 4, 1951 REFRACTORYLINING FOR DOMESTIC FURNACES William N. Butterworth, Shaker Heights, Ohio, assignor to General Refractories Company,

Philadelphia, Pa., a co vania rporation of Pennsyl- Application May s, 1948, Serial No, 24,834

The object of the invention is to provide improvements in refractory linings for furnaces, and more specially in the burner and runner bricks or tiles which line the fire box or combustion chamber of a domestic or similarly small furnace.

In most furnaces of this broad class fuel oil is injected into the fire box in a substantially atomized condition under pressure, in'order that the oil being in a semi-gaseous or vaporous state will readily unite with the air and contribute its heat of combustion to the heat-absorbing surfaces of the furnaces. However, except under the most ideal circumstances the oil vapor frequently carries with it small globules of oil in unvaporized or liquid form, while during the initial period of firing, when the furnace is still at least relatively cold, the prevalence of such globules much more pronounced. Furthermore, as each of said globules is ignited and consumed from its outer ,surface inwardly, instead of by instantaneous combustion as in the case of more volatile liquids such as gasolene, it requires an appreciable time for such burning to take place, and being in the usual forced draft of such a furnace a portion of theliquid phase of oil is carried partially or even entirely up the chimney during and before completion of its combustion. In order to ignite such globules and even the more finely subdivided vapor particles, so that substantially complete combustion takes place within the firebox, anda minimum of resulting heat is carried wastefully up the stack or chimney, efforts are constantly being made to provide as quickly as possible and maintain incandescent surfaces against which the oil impinges, whether in liquid, vapor or gaseous form, whereby when such fuel comes into direct contact with such high temperature surfaces it will be thereby instantly ignited and consumed while still within the fire box with the aid of the oxygen-laden air that is present in the draft. Under such conditions, not only is less fuel wasted and more effective heat realized, but little or no soot is deposited under the cooler parts of the furnace and chimney .to cover and insulate the same and simultaneously produce a fire hazard.

Another object therefore is to provide .a typeof refractory brick or tiles having a radially inwardly directed surface that is characterized by spaced lugs, which maybe of anydesired shape, size and arrangement, but which preferably have relatively small terminal or other portions that readily attain incandescence almost immediately upon ignition of the first fuel to beinjected into the fire box, and which thereafter continue in such state of incandescence as long as the cons on of uelfcon ch l gs mayb 2 Claims. (01. 1'5s-,-1)

of any desired shape, but preferably taper inwardly away from their supporting Wall as in the shape of cones, pyramids, or frustums of the same and while they may be substantially equally spaced upon the surface of said supporting wall, may instead be more closely arranged within a space that forms the target area for the burner and is approximately concentric therewith.

A further object is to provide a substantially cylindrical, or at least a peripherally closed arrangement of runner tile or brick which is broken only by the interposition of a single brick (or a pair of adjacent bricks) having an aperture through which the usual burner extends or projects, and by means of which the fuel is injected into the interior of said arrangement or assembly, and said runner tile being provided with the inwardly directed preferably tapering lugs which when heated to a high temperature radiate their heat upwardly through and from the upper open end of the assembly to the heat-absorbing surfaces of the furnace above the same. It is to be understood that instead of the injection of fuel by means of a pressure or other burner through the aperture referred to, the hollow assembly of lug-carrying tiles may surround a rotary burner of the type employed in some installations, in which case the fuel projected by such burner is still directed substantially horizontally against a circumferentially extending area upon the inner lugged surfaces of the said tile, and in such case it is unnecessary to include one or more apertured tile as in the case of the so-called guntype burners. In either such construction, arrangement and relationship of burner and tile, a high degree of turbulence is created in the intermixed fuel and air, as, the combination thereof mushrooms against the lugged area of the surface of the surrounding tile.

With the objects and principles of operation thus briefly stated, the invention comprises further details of construction, assembly and operation hereinafter fully brought out in the following description, when read in conjunction with the accompanying drawings, in which Fig. 1 is a front elevation of an assembled unit of the improved tile comprising one embodiment of the invention; Fig. 2 is a plan view of the same; Fig. 3 is a plan view of one of the improved runner tile per se; Fig. 4 is an inner elevational view of the same; Fig. 5 is a plan view of a segmental tile that comprises one-half of the base upon which the cylindrical assembly rests, the other half tile of said base being indicated in dash and double dot lines. in order to indicate a normal assembly, ofa pair of said base tiles;

and Fig. 6 is an elevation of the base half tile shown in Fig. 5.

Referring to the drawings, it will be assumed that a complete assembly of the improved tile comprises a pair of base sections,fa pair, of burneropening tile and four runner: orssegmentaliliner or runner tiles, it being understoodthat" the'ba'se might instead comprise a single tile while the burner aperture might extend substantially centrally through a single tile insteadiofybeingsrdefined by a pair of complementary recesses ini a pair of adjacent tiles, and that there may be any desired number of runnerforilinertile,depending upon the internal diameterfj ofithe furnacei'iie box, the thickness of said tile and'the chords found to be most economical. V y

In the present example of construction and assembly, each of the tile of said base comprises a semi-circular bottom portion l, upon which is superimposed a semi-"circular upwardly extending integralprojec'tion' 2,1providing a semi circu- .laix shoulder 3 that is sufficiently removed"ra .-dially inwardly from the corresponding portion of 'the periphery ofsaid bottom portion 'to' provide a correspondingly. semi-circular supporting "surfaceA for the lower end 5 ofthe said runner .til'es when assembled thereon. Thus, a pair of these basetiles wheneaoh is. 180 in-extent cooperate to provideha complete circular. base,as indicated Hbyboth the solid and broken lines in Fig; 5.

In. the design. herein illustrated, two complementary burner tiles 6 are shown, each being provided with a semi-circular cutout I which in practice cooperate to. provide a so-called burner opening through which at least thelnozzleof-a .gun-typeburner. normally-v extends, or through which in-any case fuelis injectedunder pressure into the interior of the-tile assembly. It should be understood that whereas most furnaces today employ liquid fuel, .suchsasra medium-1 grade of fuel oil, that is forced into -the-fire-box f-rom a small nozzle orifice under-sufiicientpressureto atomize it, gasmay be used instead, while it is possible to usefinely powdered coal dust.

The lining of the fire box comprises other than said burner tiles, ;aplurality of segmental .tiles 1 8 --:that cooperatewith said burner tiles andwith-one another, each of these tiles beingprovided upon its radially, inner-surface with'a plurality of lugs "9 that-are formed integrally with ther'bodyrof ,the tile and whichare preferably-of such.-shape:;and inward taper as toyoffer a terminal portion 10f -relatively low volume that extends wells-into: the

interior of the hollow; cylinder =when-=the :tiles are-assembled, and accordingly :into :the region ofagre'atest heat of the swirling Jgases ofz combustion, with the-result that these? terminal portions of the lugs attain incandescence-uponbeing encountered by the flame. from the "burner, and at the same time accelerate the rise in tempera- -,tureof the inner surfaceof-the body of the-tiles,

'in'addition to effecting-a substantial increase in the surface area of' the tiles, thereby: providing high-temperature surf ace areas .whichmaterially :aidin igniting thefuel' as it impinges thereupon.

In the case'of fuel oil, itis only under the m'ost ideal conditions thatlthe :liquid 1 is thoroughly atomized as it enters the tiled enclosure of the f re boxafter the" latter has become thoroughly heated'and combustion'is considered substantially perfect and-even in such installations combustion' is far from a perfect while the :liningand generalfrfurnace interior are still at:v a low temperature;as when starting the furnace. flurther- I m'o-re, lthe .1 best burner installations vdeteriorat s5 e4m g g s -w anii a saidsassembiyfsaid 5 as possible when conditions are less than the degree {if ppei'fec'tion desired, realizing that when "conditions arecorrect*the-'"combustion will con- ...tinue to be .no less efiicient than initially.

It has long been realized that perhaps all fuels al 1;.2iIid fcer-tainly :f-uel oil are ignited and burned imuch more rapidly, and therefore with less tendencytowards incomplete combustion and result- "l ing;smbkeiand;soot, if brought into more or less "directgcontacts i'th an incandescent surface, and

that it isde sirable' to provide such incandescence as soon as possible after fuel is first directed into *a -relatively -cool fire box interior; also that if such: incandescent surfaces could be made of a shape to create and-:maintain turbulence and .therebhaccelerate.the'intermingling of the .gasi- 1 f'fiedffuel and vvincoming airfthe' conrpletewom- .biustion'f; ofiithe" ruerwould be" considerably more "fnearly, instantaneous; 'withi proportionately less i fuellwa'stjediuplthe stack "or, chimney; and less ac- 2 viciimulationl of soot resulting.

.A'Accoidinglyfthe. radially inner surfacepof'each 16f, the, runners tile. is providedlwithj both vertically an'd horizontall epacedfinwardly,projecting lugs, j teats. or. knobs, which-may. be ofshbstaxitiatllyuhiliformand regular-arrangement over the surface of Lthe ltile,., or instead mayl be more closely, arranged.,-at;.that ,gpo'r'tion of the area of said tile ildirectlysopposite-and in, general alignment with Tithe burnersopening. TIniFig; 1 the concentration .1of. suclilugsis shared byltwoadj acent runner tile,

ibeingZ-bisected' by the verticahiointbetween. said stiles while in "Figs.l .3 ,and- -.-4 such... concentration .-is-Shown-as:being located substantially centrally Yoftthe single tile there shown.

40 flhe joints between-ad j acent tiles .are preferably -..irreg-ular-.in-shape, isoasLto therebynverlap wand l prevent ithe escape of ---high temperature ,gases aradiallya outwardly, past! the tile and into direct ;contact l-with-z'the= innermetallic surfaces. of the .ijemtsamaygbeof whatever-form: isidesired each w is herashownas;comprising-a radially-outenldiagnally extendingz-section -10 thataterminates inrdly sine-a ishort,*circumferentially extending ecticnfl F'f'EOmTW'hiCh BJ radialgsection lZ-termiatesainwardlysati'the :inner surface of :theeadjaentitiles-the angular joinhsurfacessof one: side no: -::e.ach= segmental atile zbeingtcomplementary to 'ithamofutheztile nextadiacent-tthereto.

- #Whemadaptinglthe inventionrto'rota-ry burners,

'rinozfrontaliaperture:is providedi as the rotarweleentzrevolves 'nponj a verticali-axis';centrally disposed e-within t the riflre :box, so ;that i-the =.:flame trikeszlthe lini'ng tiles'; in .a substantiallyscircular me of nniform elevation;:andZ-imthat case the ugs mayibeiarrangedimore;closelyetogether about rthdnternali'periphery of the lining atian' elevaioniintermdia-tez thetvertical' limits '.0f the runner cm es,swhich in such zaicaseiconstitute the entire no .oass'emb'ly, :isince no flso called hurner tiles l are tiles through at least a major portion of said assembly being provided with radially inwardly directed tapering lugs that tend to incandesce in and by virtue of the heat of the flame of burning fuel, said lugs being more closely grouped together in an area diametrically opposite said opening.

2. A hollow refractory lining for the firebox of a furnace having a burner-opening in one side, and comprising a plurality of tiles having a joint substantially opposite said opening, a major portion of the inner surface of said lining being provided with inwardly tapering incandescable cones,

said cones being more closely grouped together in an area diametrically opposite said opening and upon the opposite sides of said joint.

WILLIAM N. BUTTERWORTH.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Pfau. May 20, 1873 Krebs Dec. 19, 1916 Doble Aug. 19, 1919 Gates June 1, 1920 Bean June 27, 1922 Edwards July 2, 1929 Roberts Aug. 20, 1929 Ticehurst June 7, 1932 Wetherbee July 25, 1933 Beckett Aug. 8, 1933 Passino Jan. 22, 1985 Macchi Mar. 15, 1938 Miller Mar. 5, 1940 Steele July 16, 1940

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