US1997306A - Incinerator - Google Patents

Description

April 9, 1935. w. L. McEvER 1,997,306

INCINERATOR Filed Jan. '7, 1933 4 Sheets-Sheet 1 INVENTOR BY WLMCEz/er' j@ ArroRNEY a drying support. 4A more specificeature involves the :passage of :the 'gaseous products' of .com-- Patentedpr. 9, 1935 Y K 1 legs/,ste

Wiiuam L. ,MsEvrQYunkers/N- Ys assigner to Decade Lllmilrleraimr` Corporation, New York,

N. 'Ypa` corporation of New york Apelieauen Jaimy ,7, 193s, serial No. 650,682

` s l, (ci. noFrz) Myfinvent-ion relates to incineration and more particularly to apparatus and methods for the disposal or burning; 'of sewage sludge, sewage screenings, rubbish, garbage and other material containing a large percentage of moisture.-V

.An important object of the inyentionis toprovide new and advantageous methods for burning material of the gen-eral vclass specifiedi' 'Another important .object of the invention is to provide new and advantageous apparatus io-r .the general purpose speciiied.v A further important object el? the invention 'is to.` utilize' to `the "-fulilest :extent heat resulting'ifrom combustion 'of/mate-V riali-nthe furnaceor incinerator. ,y

VIn materials such as referred to, there is usually .sufficient moisture to necessitate the use of auxiliary fuel tolobtaincomplete and emcient dis'- posal, and it is therefore:animportantobjectof the invention to .utilize to the rfullest extent the heat resulting from the combustion of both 'the material to be disposed of and the auxiliaryfueL It `is also an .obiect of the invention to provide positive .control over'the gases produced. Alfurther object `of the invention is'sto render a'llof the f gases discharged from :the Iapparatus clean and odorless -at all times, irrespectiveof 'variation in quant-ity or duality -.of the material being destroyed. 1 y Y An important feature .of .the invention involves the passage of the gaseous products of combus-v tion `along ihoth upperand :lower facesorsides of bustione-hst along gone face .and then along :the

1 otherof :the facesof .the drying support. Y r 'f Another 3feature lrelates to the user of a drying support having, in Vaddition to an imperi-orate-v portion .or hearth, :a perforated part, `or grate, whereby apertion of the :gaseous-products of combustion `may-be passed therethrough, thus produjne in ,effect :a short-circuiting ofitfhe flow Vof gaseous products .of combustion. f @ther teatures `irs/oline .the passing of .tnefgasecus products of' combustion along the* topof a drying support in :a combustion Achamber `or high temperature zone, ybach :at -the lower side lof :said support,and` :through that portion fof the high tempera-tune gaoriegza'nd then to a discharge flue preierably leading to astack.

According to :a preferred form 0f lcarrying `out the inv ntion, provision is made Yof a refractory lined gstnucture having lan 4upper part. which'is preferably rectangularfin rshape-and 'receives the material :to .be burned through means includ ing acentral charging hopper the-ton wliiol'iv top may be flat and suspended from metal cross members, such as I-bearns, spanning the distance 'between the side walls. 'Beneath' the charging vdevice'is adryingV support preferablyinclined downwardly .toward a partition wall which serves as a support for one end of the dryinghearth, the other end being supported 'in -af suitable manL neras by a bearer bar.` The drying hearth should be of heateconducting material and preferabl-yiis made ofphigh-heat-resisting vmetal -or the' like and -while solidnear the partition wall ieper-fo` rated in the part remote from the partition wall, thus lin effect providing asecondary grate.

l:Extending from the `parti-tion wall to the Aside of the chamber is-a r-e grate or set of grat'esfon which the -mate-rial dried onf the drying supportis burned. Beneath the fire grate is an" ash pit through which is introduced a 'ho-t draft to aid combustion. The air for the hot draft may enter through a 'duct having a flat portion overlyingthe top ofthe furnace chamber and portion o f tendency toV sag. The circulation .of -air over the roof and into the ash pit is preferably eiectedby means of a forced vdraft fan locatediat the inletof theduct. y f

Hot gases from the fire grate pass over `the `topl of the drying support or hearth and, in general; around the farther edge of the support. However, due to the yperforated character vof this part of the drying support, the gases may pass down-f wardlytherethrough,v although vpartially obstructf ed bymaterial thereon. f Beneath theldrying supportis a part ofthe oo mbustion .chamber and the gases are turned -k'a'acl'z` to'fpass therethrough land alongv the lower side'o'f the drying 'hearthto-adown well or-passage-which` may .be included between the `partition wall, (serv-V ing as a Icommonsupport for the iire grate and the' `drying support, and a Abridge wall whichl proj ects upwardlybeneath-the drying hearth near the.middlethereof. Preferably tor-proper regulation of the 4gas flow the bridge wall varies 1in height so that thedis-` .during the normal operation of the incinerator.

When use is made of either oil or gas as auxiliary After the material on the drying support has been suflciently dried, it may be stoked downwardly to the re grate or grates. The water conf tent of the refuse material is usually so high that auxiliary fuel must be used, not only toY start the drying and burning of the refuse material, but also fuel, burners may be located above the fire grate and also in line with the flue leadingto the stack.

If solid fuel be used, it may be burned on thel fire grate and, if desired, onl another grate .located in the down-Well just below the level of the liuc leading to the stack. n

In starting the incinerator, there is no dried refuse material on the main grate and, if such auxiliary burners are used, there'is no'need for forced draft through the grate. Under these conditions, the fan may be leftv idle and, after a short preliminary heating, air may be admitted through a normally closed opening vadjacent ,to ther fan. After the incinerator has been thoroughly heated and combustion of material on the lire grate is assured, the opening adjacent to the fanis closed and forced draft is provided r:by the fan.

Other features and advantages will appear upon consideration of the following description and of the drawings, in which Fig. 1 is a vertical section of a preferred embodiment of the invention, the section being take along the line I-I of Fig. 3; Y

Fig. 2 is a vertical section taken along theline 2 2 of Fig. 1; A V

Fig. 3 is a section taken along the'line 3-,3 of

end walls I2 and I3 and a roof I4. The side and end walls are of refractory material'at their inner surfaces'and at their outer surfaces arepreferably insulated by suitable material I5 and are encased in steel plate I6. Although thev roof I4 may 'take other forms, it is preferably in the form of a fiat arch of suitable heat-resisting material suspended from upright walls of the furnace by means of I-beams.

are supported on a suitable concrete structure or foundation Il. Y

The sewage screenings or the like which are to be burned are introduced'into the incinerator in any suitable manner, as for example, through suitable charging chutes IB extending through the roof I4. Passage of screenings through the charg- 4ing chutes may be controlledby means including vautomatic doors I9 normally heldin closed position (Fig. l) by weights 20. It will be evident that when screenings accumulate sufliicently upon thedoors i9 the doors will vopen and discharge therscreenings intothe incinerator. Y.

The screenings thus introduced fall upon a dryingsupport ,2I and whensuitably dried thereon are transferred to re grate'22 where the solid" matter is consumed. Thegrate'22, as here shown,

, is supported at one side'by the end Wall I3 and `a part serving as a drying grate 21.

The side and end walls may be supported in any suitable manner and as-here shown at the other side by a partition wall 23 of suitable refractory or fire-resisting material. The wall 23 may-also be utilized to support the drying support 2l at one edge. Support for the opposite vedge of the drying support may be effected by a bearer bar or beam 24 of suitable heat-resisting metal. Preferably the bearer bar 24 is somewhat higher than the top of the partition wall 23 so that the drying support 2| while forming substantially a -continuation of the fire grate 22 is slightlyV inclined so as to facilitate transfer ofv the material, as by stoking through one or more openings 25 inthe side walls, from the drying support to the rire grate.

'The drying support 2l is substantially contin- `uous'near the partition wall 23 so that this part serves as a'drying hearth 26, and is of open construction near the bearer bar 24 so as to provide As shown in Figs. 2 and 3 the ydrying support 2I is preferably made up of a plurality of bars or members having flat tops and' central reinforcing flanges projecting downward from said at tops. As shown in Fig. 2 the nat portions of these members form substantially a continuous surface in the drying hearth portion of the support, and the grate portion of the drying support is provided by recesses in the .edges of'said fiatV tops.

Although there is no definite division in the interior ofthe incinerator the portion above the nre grateV 22 may be considered as a burning chamber or zone andthe portion of the said intent completely burned. As indicated in Fig. 1,

the `combustion chamber extends beneath the open portion of the drying support 2l and is provided with a floor 28 of a refractory material, which is insulated from the concrete foundation or support by means of a layer of insulating material I5. The'gaseous products of combustion passover the drying hearth 26 and either around or through the drying grate 21 into the portion of the-combustion chamber beneath thedrying grate, are directed rearwardly beneath the drying support, and are withdrawn from the portion of combustion chamber beneath the drying hearth. l

. rIt will, therefore, be Vevident that material on the drying hearth will be subjected at its upper surface to thepdrying action of the gases of combustion passing over the same and that the material on thedrying grate 21 will be exposed to the gaseous products of combustion not only above and below, but in the interior of the mass due to the fact that unless the mass is too thick and dense a portion of the gaseous products of combustion will be drawn through the drying grate. A great advantage arises from the use of a metallic drying support 2I in that it enables the use of long narrow slots, which would not be practicable to form'in -flre brick and similar construction, whereby thegases arev permitted to pass through the support freely and all but very small particles of solid material are held on the grate.

To support combustion in the incinerator, itis necessary to supply a suitable amount of air, and,

in, order to increase the efficiency, the air fintroduced into the incinerator is preheated by using-it tor cool certain parts of the incinerator. If the roof -.I4 becomes too hot, the I-beams which support it will tend to sag.- It is, therefore, de-

sirable to cool said top and for this purpose said top' and is used as a bottom of'a closed .box-29. formed byta steel plate cover -cortnected.withthe upperledges of the steel plates I6 enclosing. the side Aand end walls of the'incinerator. .Nearf-the wal`1`i3, the box thus formed 'is connected by means vof a downwardly extending duct with a porter opening SI connecting withthe interior of ash .pit 32 beneath the iire Agrate 22. Adiiacent to the-walll2, the box is connected by means of an elbow 33 with a forced draft fan lmounted on the Atcp of the box and the elbow is providedV with a door 35 to supply air to .the fincinerator when it is working under natural draft.

As hereinbefore stated, the gaseous products of combustion after` passing beneath the drying `hearth `it are withdrawn `.imm 'the incinerator.

rIfhis might be done by means of a iluefextending from I'the position just below the drying hearth to a stack or other means of producing draft. However, as illustrated, said gaseous products'of combustion are directed Ydownwardly through a down well 36 `between the partition wall -23 and a bridge wall 3l of whichthe top is almost -directly beneath theA division between thedrying hear-th and the drying grate. As here-shown, the down well 35 extends lfrom side wall I0 to side wall* Ii. From the down well '3B thegaseous products of combustion may pass -to astack or other draft producing means, through a horizontal flue 38 `connected with the down well-"36 above its bottom so as to provide atthe bottom of the hearth 2.I to .the upper side of the .perforated section or drying grate 21 where a portion of the' down'well adust coliecting chamber -or pit39l The 4bridge wall 37 serves tofdirect the'hot gaseous productsof combustion upwardly so -as to contact with the lower face of the drying hearth. If the top 4of Athe, bridge wal-l were horizontal from side wall IIi -to side v-wall JII -therewould be a tendency for the greater portion of the gases to pass through the central partof the passage so that the rcentral part of the drying support would be heated more than `the portions vnear the side edges, and the Amaterialen thedrying support would not be vdried uniformly. To this end the bridge wall Slis ymade higher vin the center-and gradually decreases in` height toward Vthe side walls. As indicated in Fig; 8 this-decrease in height is accomplished yby giving the rtop -of the wall4 a stepped formation. In addition toV Stoke holes l25V for working the material from the drying' support to the regra'te, provision may be made of Stoke holes 39 for handling the materialen grate 22, stoke ho1es--40 forv removing ashes from the ashpit 32, stoke'holes 41 for removing waste material from the floor-,'28 of the combustion chamber, and stoke holes II2 for removing .dust from the dust chamber 39'at the bottom of the down wel1`36. Normally .all of these stoke holes are rclosed and for this purpose 60: are provided with doors 43.

This incinerator is intendedparticularly for burning wet Vscreenings and thelikeand it is evident that it cannot be put into operation without the use of auxiliary fuel and that it may be necessary to use auxiliary fuel during normal operation. As illustrated on the drawings the auxiliary fuel to be used is oil introduced through suitable burners 44 of which two are shown acting through openings in wall I3 `iust above the re grate and one is shown acting through the.

bridge wall 31 opposite the end of the flue 38. The burners illustrated include fans 45 by which air is mixed with the oil as desired, and as a matter of fact, excess air may be introduced to support combustion of solid matter on grate 22 and .of .combustible included in the gaseous products of combustion.V i 1- Oxygen. toinsure `substantially completecombustion in the down well 36 and flue 38 may be supplied inany suitable manner, as from air en teringthroughinlets 45 in the side VwallsII'l and I I at the upper part of the. down well, due to the pressures in the .down well :being .below atmospheric pressure. I

In starting with a cold incinerator, 4thefoperation may be substantially as follows:

. .The burnersw44 at the wall I3 are-put `int seryiceat .substantially the same time, .the burner 44 opposite flue v38 is also put into operation, and

tion, material may be introduced .through .the

charging ichutes -I 8 and counterbalanced doors. I9, so as .to fall on the .drying support 2I. As the material accumulates on the drying support it is stoked through the holes or openings 25' so as to spread it Amore or less uniformly over theV dryingl support and thus subject as much of the ma. terial as possible `to direct drying actionof the hot gases produced by the combustion of Athe auxiliary. l

AIt will be seen that the gaseous products cf combustion pass above the material on the. im perforate portion 26 ofthe drying support vor hot gases or Igaseous products of combustion may pass downwardly through the material andthe openings in this'part of the drying support.A The Vremaining productsV of combustion pass over .the endof the .drying support or hearthA and the edge the uniformity .of flow, and from the bridge wallv pass downwardly .through a down wel136 to the entrance of a'iiue 38 lthrough which the hot gasesv may be discharged into a stack or other draft-A producingmeans, not shown. VIn this way a maximum area of the material is exposed to the drying action of the hotlgases, thus tending to reduce the amount of `auxiliary fuel required for drying and .combustion and to produce a dry product on the `drying support or-hearth. l

When suitably dried on the drying support ZI the material is stokedonto .there grate 22 where it. burns, air `containing the-oxygen necessary for combustion being drawn in through and lpreheated in the ,box r29 at the 'topV of the incinerator and Ybeing- .supplied at .the lower side ofthe fire grate22 vthrough the ash pit '32. The non-combustible Vmatter or ash lformed on the grate 22 falls through the .openings in fthis grate into fthe ash pit 32 from which it is removed through .doors '40 and may be conveyed to a suitable place of described for the auxiliary fuel. As soon `as combustion of such driedA material begins on grate 22,

the amount of auxiliary fuel required is reduced in proportion to the amount of heat produced in this burning operation. All of the gaseous products of combustion must pass from the furnace eny down well 36 will be caught in the dustpit 39 from which the solidsmay be removed .through one or morecleanout,doors143j Under some conditions it may be desirable to use solid, fuel on the grate 22 to start the furnace and toheat the outgoing gases by fuel on a grate immediately above thevdustpit'at the bottom of the down well, as shown inFigs. 4 and 5.v With this arrangement it may, be necessary in starting the apparatus to admit air through adoor 40 in the side of the ash pit 32 beneath the re grate 22, and to admit air to the lower part of the down well through a cleanout door 43a connected with the dust pit 39a, which in'this formis narrow and is flanked at its top by section 5| of a iloor for the down well, and/ or through one or more doors 52 at'o'r abovethe levelof said grate and floor section. In this form, dust may collect on the floor Vsections 5I and may be removedrthrough the doors 52. Material may besupplied to the grate 50 through a central door 52 whichmay also be used when it is desired to Stoke material on the grate 50. f

It should bef understood that various changes may be made in construction and arrangement and that certain features may be used without others Without departing from the true spirit and scope of the invention.

Having thus described my invention, I claim:

l'. In an incinerator, the combination with a burning chamber and a fire grate therefor,y of a combustion chamber, 'a drying hearth in Vsaid combustionchamber and having one edge adjacent to'said re grate, a drying grate adjacentl to the opposite edge of said drying hearth, adown well constituting a combustion chamber outlet beneath. said hearth, a bridge wall beneath the adjacent edgesof the drying hearth ,and drying grate and having its top spaced therefrom to provide a passage, said top. ofthe wall being so shaped with reference vto the top of the passage that the height of the passage at the middle is less than at the sides to limit the flow of gases at the middle and thereby increasethe flow at the sides and render the flow more uniform across the passage, a laterally extending flue connecting with said down well and a burnerjet in said down well opposite the end of said ilue. Y

2. In an incinerator, the combination with a burning chamber and a lire grate therefor, of a combustion chamber receiving gaseous products of combustion'from the burning chamber, a drying support in said combustion chamber, a combustion chamber outlet, said drying support and said outletbeng so arranged that said gaseous products pass in one direction over the upper face of the support and in the' opposite direction beneath the lower facelof the support, and means for restraining the flow along the middle of said lower face andthereby rendering the ow of gaseous products at the lower face substantially uniform throughout vthe width of the support.

a 3. In,v an incinerator, the combination with a burning chamber and a fire grate therefore, of acombustion chamber receiving gaseous products of combustion from the burning chamber, a drying support insaidcombustion chamber, a combustion Achamber outlet, said drying support and said outlet being so arranged that ysaid gaseous products pass in one direction over the upper face of the support and in the opposite direction beneath the lower face ofthe support, said lower' face being substantially flat across the widthof said support, and means including a wall higher at its middle and lower at its ends to render the flow of gaseous products in said opposite direction Vsubstantially uniform across the width of said support.

4. InA an incinerator, the combination with a burning chamber and a fire grate therefor, of a combustion chamber at one'side of Asaid* burning chamber, a drying support in said combustion chamber inclined downwardly to one edge of said re grate, and a down well positioned beneath the portion of, said drying support adjacent to the re grate whereby the gases of combustion from the nre grate will pass along the` upper side of said support and back along the lower side thereof, said support being formed of heat-resist ingr vrmetal with an imperforate portion near the nre grateand another portion'further from the fire grate provided with long narrow slots permitting gases to pass through but retaining most of the solids of which some disposition must be made.

5. In an incinerator, the combination with a burning chamber and a re gratel therefor, of a combustion chamber at one side of said burning chamber, a drying support in said combustion chamber inclined upwardly from one edge of the fire grate to a position spaced from thewall of the combustion chamber to form a passage through which combustion gases from the fire grate may be passed, and a down well beneath the drying` support adjacent to the re grate so that combustion gases will-be drawn along the top of the drying Vsupport and backward beneath the drying support to said downwell constituting anV outlet, said drying support comprising a substantially imperforate part near the fire grate andra perforate portion remote therefrom and being formed of a series of metal members fitting closely togetheradjacent to said re grate and providing at the remote portion substantially long narrow slots to ,pass gases therethrough while retaining solids of appreciable size, said slots being formed of recesses provided at the edges fof said metal members.

` WILLIAM L. MCEVER.

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