US2333141A - Water-cooled grate - Google Patents

Description

1943- L. M. BARDEN 2,333,141

WATER COOLED GRATE Fild July 31., 1940 s SheetsSheet 1 in 5 5 17. Z E F L es/fe flare e12 3 Sheets-Sheet 2 L. M, BARDEN WATER COOLED 'GRATE Flled July 31, 1940 Nov. 2, 1943.

L. M. BARDE N- WATER COOLED GRATE Nbv. 2, 1943.

Filed July 51, 1940 3 Sheets-Sheet 5 oaoaoouonoooqoooooooooogou m 1H? Leslie 1%501 04212 Patented Nov. 2, 1943 UNITED STATES PATENT' OFFICE" 2,333,141 I a y o v WATER-COOLED GRATE? I v Leslie MiBarden, Downers Grove; Ill; a'ss ig 'nor to j o J oseph J. Heritage, Chicago, Ill. I

Application July 31, isimseriarNo. 348,803 12 Claims. (o1.12z 374) 2 There are a'number of fuels having a low relative cost orhaving other advantages, such as a high heat content and a low ashcontent, which are burned with difficulty on ordinary grates in hand fired furnaces.' Some of these fuels, such.

as petroleum coke, tend to form a solid bed or slag or clinkers when an attempt is made to achieve high rate of combustion. Difliculty is also encountered with petroleum coke and with coalsof high sulphur Content with burning out of the ordinary gratebars' because of the corrosive nature of the ash or clinker formed and because of the hlghtemperature to which the grate bars are heated. I

It hasbeen found that these difiiculties can be obviated by 'the use of water cooled grate bars which retard or reduce the formation of clinkers and which remain relatively cool and therefore not subject to high temperature corrosion.

Many forins of water cooled grates have "been provide a water cooled grate which is extremely simple in: construction :jand involves a' minimum amount of material fai'id whichlcanl be installed in a 'boiler' with the minimur'neamount of work. Another'object of this invention is to provide'a :wateri-cooledxgrate whose design is as simple ast possible and which nevertheless has agood -circi1lation :through it.) a

-- i "'Another object of this invention is toprovide a" simple water cooled grate which will improve i both the heating?'capacityandthe' efi'iciency of the boiler inwhichit is installed; 1

" 1 (One of the principal features'of this invention consists iii-making the grate ofsteel' or wrought imn tubin'g welded together and in two separateportions which ma'y bev easily inserted into the'mI-urnace eitherithrou'gh the fire doorsor throug'h'theTash'pit'doors; '5 Another feature of this invention isthe provision of short angular connecting" tubesi be? tween the headers of the water-cooled rate and the water legs of a boiler andarranging the connecting tubes in a particularmanner to in- I sure 'good 'circulation'ofi water through the grate.

-Anothenfeature "of this invention when used in connection with-a horizontal returntubular boiler i s the provision'of risers within the fire 'box iormirig "direct-connections between the will insure goodcirculaticn of water through the grate. 3

Other objects and features of the invention willappear fromthe following descriptionand claims and the accompanying drawings in Figure 1 is a side view oflone of the preferred forms of 'the invention installedin the combustion chamber of a stationary locomotive type boiler, the boiler and setting being broken away ure 1, looking in the direction of the arrows V headers o fthe water cboled'grate and the boiler,

the headerEbEing arranged in a manner which E Figure 3..is a; plan view of the grate shown Figure 4' isna section on the line IV-IV of Figure 3,-looking in'the direction of the arrows;

Figure 5 is a side View of another of the preferred forms of the invention as used inconnection withra horizontal return tubular boiler, the

type boi1er l0 of moderate size, such asis commonly used for' heating purposes. The boiler I0 is placed in aibrick setting H which provides the ash pit '12, intthe conventional -manner. Access torthe fumace-li of theboiler I0 is provided through doors I I and (IS on the front of the boilerandaccess to the ash pit I2 is provided through a'door 15 located below the front of the boiler. t

The grate I1 is formed almost entirely of steel tubing welded together as shown in Figures 3 and 4, and is made in two separate .halves. Each half comprises a frontheader I8 and a rear header 19 joined by a plurality of straight tubes 20 which form the part of the grate upon which the fire rests. Each section of the grate H is provided with lugs 2| welded to the grate tube at the inner end-of the grate section and provided with apertures for receiving bolts 22 by means of which the two sections of the grateare bolted 'togetherf 1 J Each of the-front headers l8 isprovided with a tubular elbow 23 welded to it and extending upwardly and rearwardly and then laterally outwardly. Each of the rear headers IEI- is provided a furnace.

putting "andconnecti-n-gt e blow o P One blow-off connection 26 is arranged to re ceive a blow off-pipe 3! which leadsfiadaawalv 32 located above or at one sideof the ashpit door l6.

Since the grate H ismade of two separate sections, each of these sections, nomprisin'g Lthe to the boiler tubes 31 opening into the back of the furnace l3. These factors, coupled with the fact that there is less resistance to circulation from the boiler tubes through the large rear header 5 9 and the two rear connection elbows 24 and 25 than through the small front header !8 and the single front connection elbow 23 insures that the heated water and the steam generated in the grate tubes 20 will .fiow towards the rear of. the boiler and into the water legs through the rear header i9 and the rear connection elbows 24 and 25.

"of *thek'irislention shown in Figure 1. modified form. of the invention, the grates 40 In Figure 6,1 have illustrated a modified form In this are formed in two sections and are generally similar "to the grates I! in the first form of the invention. They comprise tubular grate bars front and rear headers l8 and I9, the grate tubes 20, the front and rear circulation elbows 23, 2'4; and 1'25, :blowzoff -:connedt'rons 26 and :28 or 21 and 29, can be entirely assembled'i'and welded togetheroutstde :of r'the bm'ien. The "two sections Jean thenibe inserted TmllD the f urnace '13, either by way 'of pit ii'oor 1:5 azndthe r ashpit I2 or byway of the furnace doorfl fil. if n'ecessam the furnace doors M and l 52nd .the doorrtmmefi may :be :remcimdito tacilitateithe insertion of the ponti'ons mf the gcate'tinto :tlne

The grate' sections placeduiipon brackets -34 'and35 at the fimntanrl wear of lthelfrrrnace,

each 'of' the'sheaklers. i118 sami :19 resting upon "the brackets one end of the l fiumace, as vshown in Figure 1. circulation nelb'ows 323,2 4, and 325 on use side walls 36' elf the fuma'c-ze is new iniariked, the grates GIT. are lifted wp'and lowered into the ash pit .IZ, and'holes are cut by means of away-acetylene terch gor otherfisui'teible means ling the *furnace walls $5 at lthepdaces'marked Atteh theholes in the furnace walls M LhaVe'been cutthe grates I? are -replao'ed in posiition on the bra-cl:'etsv 34' and-3S, the mo sections are boltefl together, and the ends of 'the elbows I'M Land 325 are weicled to" the furna'ce walls, thereby' connectingithe passages within the grates to watei' legs 'df 'Tl'ie installation' fiis eempleted by The location of the Lends off/the M extending between front and rear headers t2 and 43 which rest upon brackets 34 and 35 at the front and :rear of the furnace -43. .Each of the two frcmt headers 42 is pnovidecl with a connecting. elbow/-44, similar to "the connecting (elbow as in the first tormgef the invention, which extends upwardly and rearwardly and ,then latem-ally outward-1y and is Welded into the .-side wallet of the furnace. g

Each of the two rear headers 43 is provided with two connecting rel-bows 41.5 and 6, but these, :insteadof being connected to the side wall 35 "of the furnace, rise-vertically and then turn back into tube sheet-41 at rear aof the t-f-u-rnace, the connection :to the tube :sheet i being made by Welding. It Will be noted that, as i-n--the first formiof the invention, there are two rear connection elbows 45 and 6 and bne front connection 'elbowdill for{each section of the grate zand thatthe rear connection -eilbows fist-and 46 exhigher and are more in thepath-of the names than the front connection wel'bew 4 1. Be-

7 cause -of this :and because :of the fact that the will be noted that bofth the front andirear headers 15 and as are: langer than the grate tube's 211' and that the rear'heailier ii! is' substa'ntially larger than the f-ron t 1 8;

diameter, the front header is three inohesfi 'ameter, and the rear header is f-our rearjsheader @4 3 isvslightly higher than the front Zheazter t2, the cincrulailfi'om nf wart'er'through the grate will be maintained :in the same manner as :in the form of the iinvention.

' *rAnothermodification of the form of the :in-

. :he'ing mrovided with connecting eel-bows, is :pro-

diameter. It will also be noted'that the gratetubes 20 slope slightly upward towards the rear of: the furnace, and that two ieireulati'en elbows $4 and 25 are provided on--eaoh rear Eheader fs,

whereas 'fonly one cimculialtion elbow- 23 providedyen the 'fronthe'ader -18. Mose apparently minor d'etail's ane of. great importance as they are believed te be the for practical- LAlthough Ithe inlmowsfazfi, 24 i5 aentend at broth 'zthe .frorrt ianel near, 'irgo'od circulation through the groltcsfisfsseoured because of the slight incline of the greatJtubes 32.0 and because of thetact thatlthe rear (circuwidedwith aipair of'ri-sers and- 55 whose-upper ends are welded into :the acrown sheet-"51 of boiler. One "riser 156,, which "is connected .to the header $3 near'the side r-ofithe furnace, is fastened into the crown sheet :5? :near the *side of. 'the hzfurnace, and the other rise! :55, which is connected to :the: header 53 near the :oenterjof the furnacekis'fastened into the crownisheet :5'1

sheet n --threugh which m tubes}! -t s,

thus providing an arrangement which: does "not :grateba'r 13 to the rear end of the boiler and interfere :withithe cleaning 'of the fire tubes 31 and which neverthelessrallows therisers '55 and 56 to. extend up to the crown sheet 51. In this form.of the invention, exceptionally good circulationiis provided because of the "relatively great height of the risers 55' and 561 and theirp'osition directly in front of the tube sheet 41. Inthe installation of this form of the invention, the rissers 55. and: 56. arelwelded to the headers 53 after the'r'g'rates 50." have, been permanently placed in position, since the length of ,the'risersimakes it impractical to introduce the grates intofithe fur- 'nace.'with" the risers 'attached.""- 1 former the invention which is particularly adaptedrfor usewith horizontal return tubular boilers is illustrated in Figure 5.' 'In this construction, the cylindricalboiler 60 is supported by hangersil from beamsi62' carried by uprights B3. Theboiler is provided with'a setting. or casmg 64 which may beef 1 steel or masonryor both "andlwhich contains a furnace 65 located below the'boiler 60 and formed ofsuitable refractory" material. Access to the/furnace 65' is provided through fire doors G6, and access to the ash'ipittlrbe'low the furnace is provided through 'ash pit doors 68 in the conventional manner.

. The grate lllijis formed :in two sections, as in the previously described forms of theinvention,

and'eachofthe sections comprises frontand rear headers .II and 12 Joined by arplu'rality' of, grate tubes1l3 and'iconnected to the bottom or belly" of the boiler 60 by risers "Hand '15." 1

There is one riser H for each-of the two'front headers ll, these risers being placed at the outer ends of the headers -'|l and extending up near thegside wall of the furnace so as notgto inter- 15 extend throughthe shell. of -the boiler and project upfwithin the .boiler as .far as may be' practical. In general, the height 'to which the risers 12 can projectwithin the boiler is limited by the fire tubes 11 characteristic of this r type of boiler, but [this distance should be made as great aspossible without obstructing the end of,the' riser 15 or "placing it above the .water lineoftheboiler. In installing this form of the invention, two

' halves of the grate are fabricated as in the other forms, of theinvention, but the risers 14 and 'I5are not, secured to the main portionof the grates until the grate is; set in place inqthe'furnace. in their proper place and welded into position.

It will be noted that, in the form of the invention shown in Figure 5, the rear header "is a slightly higher than the front header H, as in the other forms of the invention, and that the upper ends of the rear risers 15 are at least as high as the upper ends of the front headers 14,

even though the front headers 14 enter the boiler to one side of the center at a point above the lowest point of the boiler while the rear risers 15 extending up from the inner ends of the rear headers 12 enter the boiler at its lowest point.

7 a It will also be noted thatthe rear risers 15 lie directly in the path of the flames and products of combustion from the fire bed resting upon the The risers l4 and 15"are then located that they will therefore receive much more heat than the front risers 14. Thesefacts insure a good circulation of water through the grate and prevent anyportion of it from overheating while atthe same1time greatly increasing the heat absorbing capacity of the boiler unit. v v

.1. From the above it will be seen that rI have pro;

vided water-cooled grates which are extremely simple and which are nevertheless arranged to provide positive circulation of the water therein. It will also be seen that I have provided watercooled grateswhich can be installed in internally firedboilers, return tubular boilers and other forms of boilerswith the minimum amountyof piping or other complications, and that thegrate itself is so simple and comprises screw parts as to allow'it to be, economically manufactured for individual boilers.

WhiIe I have" shown only four of the preferred tion shown in Figure 5 maybe employed with other .formsof boilers similar to the horizontal return tubular'boilen such as; for example, the

'fHerbert. detachable fire box boiler :which differs 'from, the ordinary" horizontal returntubular boiler in that; it is provided with ya number-of horizontal water tubes, at each side of'the fur;-

nace, these tubes-extending between. upright .headersconnected t'o the main boiler drumr -I therefor claim all constructions falling within the terms of ,the following claims.

I claim as my invention: i i

1. A1 boiler installation comprising afurnace, a boiler" forming at1east'one wall of said furnace, front and reartheaders" at the bottom 10f said furnace,"saidrear header being at a higher levelthan said front header, tubular grate bars extending between said headers, meansin said furnace for confiningwhe flames and the products of combustion "in apredetermined path from a fire ingaw'vall of said furnace.

2. In combination, a boiler having a furnace at least partly surrounded by water spaces, a grate at the bottom of said'furnacasaid grate comprising tubular bars extending between headers,

means insaid furnace for confining the flames and the products of combustion in a predeter mined path from a fire resting on said grate,;and elbows rising fror'nsaidheaders and connected directly to at lea'stcne of said-water spaces, the

the other of said headers, means in said furnace for confining the flames and the products of combustion in a predetermined path from a fire resting on said grate, and elbows rising from said headers and connected directly to at least one of said water spaces, said elbows rising from the upper of said headers into said flame and combustion path, there being at least one more elbow risin'g'g f r'oni the" upper oneof' said header than irbznitheiower one orsaidheaders; f

1 4511'; lcor'nhination', a boiler having a: furnace at least earn surrounded by" water spaces, a head at the bottom Iront o f said: furnace,- a second hea 'de'r atthe *bettern. rear of Said "flirnace and slightly higherthan sald firs't header, 1111b es forming grate-"barsextending between said headers, fire-tubes in said furnace so positioned to'receive the flames and products'of combustionas to conbottom're-arof said fnrna'ce and slightly higher than said first header, t1ibes forming grate bars extending between-said headers-fire tubes in said T-urn'ace so positioned to receive thelfiaxnes and products ofcombustion-was to control their path of r'nov er nent fromsa fire res'ting on said grate bars, Imeans oonnecting said *irbnt header tonne or saidiwater legs, and elbows rising into said fiamerand combustion path from saidrear header into said :iurnaceand connected directly to one of :said water .legsj said el bowsiorming the sole oomiection "between' 'sa'id .rearheader's ahdsaid 'boi'ler'. I 1'1 i i" 6. 1m combination; ;'hoile1: contamin'g a-furname-arid fire iub'es-extendihg fromtheback o'f sai d furnace; a header witliin' said "furnac at the bottom front thereofi a 'second header Within said furnace at the bottomnear thereof and slightly. higher than said first header, tubes formgrate ibaits extending between said; headers, me'ansiconnecting said first .heaideruto said boiler,

h;nd eihows rising npwardly and forwardlyfrom :z'ear header-12nd connected to the side wails of said furnace'said :elbowszbeing located in the path mi flame and, products of combustion from A a fire resting on said grate tubes to said fire tnb'es ii-"721K water cooled .grat'e for use with boilers having internalfurnaces, comprising front and rear fheaders, Tstraight tubes extending :loetween and weld-ed to said headers and forming igrate bars, :and "connecting'elbows welded to said headers and lying in planespassingthrough :said headers :and ,eonverging "upwardly; the ends" of *saidielbows extending slightly jbeyond the' ends. of

the-side WEtHS'Of saidfurna'oe.

fifiAwater cooled grate for use"with looi'lers having 'mtern'arfurnaces, comprising front and rear headers, 'sai'cl 'rea'r'header being larger than 'said front headen -straight tubes extending between rand weldedtosaid headers and fonning grate -bars, Jami connecting elbows welded tosaid saidwheaders and being adapted to be: welded to headers andxlyin'g in planesv passing" through said headers and converging mpwardlmsthenumberof Iconrie'oting elbows welded to 'sa'id 'rear headers being larger thari the numbenthere'of welded to said front'jheader, 'andz-the. ends of :said elbows ex- ;itending-slightly heyondathe ends of saidheaders andgbeing adapted to 'be welded to the side wall :offsaid furnace; J i a {9:111 ,comhination', boilereoen'taining a fur.- na'ce having arsheet wall :at the: back thereof, fire tubes opening, into the upper portion'of said sheet Jwell; a-reargh'eader in front ofandratthecbottom of saidii'sheet :wall, a. 'frontheader' at the front of said furnace and :slightly lower than said :rear headenj tubes' forming grate bars extending bectweenwsaid headers, means connecting said front header. to said boiler, and tubularzmembersextending up into said furnace from said rear head er :"andmonnecti-ng the rear header to said sheet walladjacent-saidfi-rejtubes;-

- '1 j"? 1 If). in a liot waterzheating system having a furfnacepzwiith a fireebox andsaiboiler;iaportion of said boilerg'fomning awall closure for said fire-box, rand" as grate at the bottom of ,saidzfire-box; said grate being formed of connectsd f'h'ollow members including a, header at the front end of 'said firebox-ya headena't the-rear end of, said fire-box at .alevelabovethefront header, grate members extending between saidheadersaandrisers extending upwardly, fromxsaid :heade'rs into flow com- 'municati'on with said: boileh-the 'risersl'from one of said headers projectingrintortheipath of'flanies and combustion .produotstfiowing from Ia fire rest- .ing on 'saidigrate members "7 11. a'hot-water heating .system'having a furnaoe with a Tire-box and a boiler; aportion of said boiler forminga wallfolosure for said' fire-box, 'afi grate formed'in a plurality of sections, means removabily'connectingsaidsections together, each g-rate" section hai/inga hollow headerat the front end of said fire-box, another hollow header iarger than fsaidlffront header at the rear of said firesaid rear header losing positioned above said front header, ,hojllow sloping grate L ner-fibers ex-j tending ioetweeh said headersian ol connections inside of sa' 7 re; oxiljetween'said headers and the boiler' 'wal'l 'closurejor said firebox: f in combination, fa poilerjcontainingf a fur nape having an outlet 'at'tnerea; end thereof, a h d r th fl a m n ce t the bQ- O 'frorit thereof, a second 'jheade hin said furnace at the h'ottomfiear thereofl hollow grate bars ex tending b'etween" said headers; means connecting said first header'to the boilergand hollowjmern hers irising upwardly; and forwardlyirom said rear header andconnecteditofthe side Walls of said furnace, said hollow'i'neinbers being "located in the p'ath of flames and products of "combustion flowing from a fireresting on said grate'ba'rs to said-furnace outlet; r LESLIE ML-BAR/DEN.

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