US2123397A - Retort for underfeed stokers - Google Patents

Description

July 12, 193s.

2 Sheets-Sheet 2 J. C. BOHMKER4 RETORT FOR UNDERFEED sToKERs Filed April' 22, 1957 4 5 tion.

Patented July i938.

PATE'NT oFFlcE RETORT FOR UNDERFEED STOKERS Joh'n C. Bohmker, kee, Ill. Application April 22, 1937, Serial No. 138,403

14 Clama.

This invention relates to retorts orburners for automatic coal stokersand particularly to improvements in the construction of -such devices and the means for distributing air for combus- The main objects of this invention are to provide an improved retort construction; to provide an improved arrangement for distribution of air .to the interior of the retort and to the surround- Ving fuel bed; to provide a retortconstruction in which the tuyres are less likely to become choked or clogged; to provide an improved tuyre construction; to provide an improved tuyre arrange ment whereby 4air will be distributed equally to 15 all parts of the fuel bed; and to provide an improved and simplified retort construction wherein burned'out or damaged sections can be readily replaced. I

vAn illustrative embodiment of this invention is shown in the accompanying drawings in which: Fig. l is a perspective view of the improved coal-burning retort and it's fuel supply tube.

Fig. 2 is' an enlarged plan view of the same showing its formation and arrangement. V Fig. 3 is an enlarged fragmentary detail taken on line A3--3 of Fig. 2 illustrating the tuyre ar-` rangement.

Fig. i is an enlarged fragmentary sectional view taken on line 4-4 of Fig. 3 `showing the arrangement, oi tuyres for lateral air distribution to l the surrounding fuel bed. A

Fig. 5 is a sectional view of the improved retort as taken on line 5 5 of Fig. 2, showing the same as positioned in thecombustionchamber of a furnace. or boiler.

Fig. 6 is a sectional -view taken online G--B of Fig. 5 showing the arrangement oi the lower tuyre ring.

Fig. 7 is a similar view taken online 'i-i of 40 Fig. 5 showing the arrangement of the upper tuyre ring and,`

Fig. 'd isv a fragmentary perspectivgdetail of the vtuyine rings illustrating the interlockingmeans for the tuyre ringsand the arrangement oi air channels leading to the' uppermost air ports.

In the form shown in the drawings, my improved retort comprises abase `section i, a 'top section or shell vtand a retort body within said shell comprising an upwardly extending body Vmember or ring t, a lower tuyre memberl or ring t, and an vupper tuyre member or ring t; all arranged to provide an open ended retort into which coal ior combustion Iis supplied by a worinC conveyor t. operating in a conveyor tube i and (Ci. 11o-45) entering the retort through an intake 8 leading into an upwardly curved throat portion i which discharges upwardly into the body ring i of the retort. y The throat portion d is formed integral with g the retort base i and the door iii of the throat is curvedv upwardly in -a mathematical curve which is known as the Schiele antifriction curve. This construction of the retort thro'at equalizes the friction over the curved oor of the same so jm that less power is required to force the i'uel from the conveyor tinto the retort.

As shown, the tuyere rings t and 5 are arranged to iit and nest one above the other, ontop of the body ring 3. `The retort shell t is spaced away 1l from the retort body and is formed with an inwardly turned flange-like portion il at its upper end and the inner margin ofthe portion ii is turned downwardly so as to nestingly engage the upper tuyre ring 5. Thus, means is provided to 2o connect the vertical side wall of the shell t with the upper edge of the uppermost tuyrev ring t and close off the space between the shell ii and the retort body.

, The body ring 3 and the tuyre rings t and t 2li are formed so that when -assembledthe retort will have a smooth upwardly and outwardly sloping side wall which extends ush with the inner margin of the inturned portion il of the shell 2. thus forming a retort pot which extends upward- 30 ly :from the throat portion d with a gradually increasing horizontal area.

The body ring 3, which is shownin the form of an invertedtruncated cone, is arranged to ht onto Athe throat portion t as shown in Fig'. 5 and 35 a lug or key i2 is provided on the bottom margin ofthe body ring 3 for interlocking engagement with a notch formed inthe upper edge of the throat 9, so that when the body ring 3 is set thereon; its proper angular position will be hxed. The M purpose of so positioning the ring 3 will subsequently be shown.

The upper margin oi the ring' t is proy vided with an annular groove i3 Yon its 'inner M periphery to receive a depending annular hangelike portion it on the inner lower margin oi the tuyre ring t which is arranged to be nestingly set upon the body ring i.

Also the inner upper margin oi the tuyre ring 5u i is provided with a similar groove it into which an annular depending ange it on the inner botyprovidea seat into which a downwardly extending lip I1 of the inwardly-turned portion I I of the shell 2 is-arranged to set.

Thus, when the several rings comprising the pot or body portion of the retort are properly assembled and the shell 2 is set thereupon and bolted down to the base'portion I, the entire retortbecomes a unit in which the several parts are securely locked together.

As shown, the tm're rings 4 and 5 are arranged to provide angularly spaced horizontal slot-like ports or tuyres I9 and I9 respectively, which ports providecommunication between the interior of the retort and space 20 between the shell 2 and the retort rings. 'I'he Ispace 20 communicates with an air space 2I surrounding the throat portion 9 of the retort base and the space 2I leads to openings 22 and 23 disposed on either side of the throat inlet portion 8. The opening 22 is arranged for connection to an air supply duct 24 and the opening 29 is arranged as a vcleanoutpassage for the removal of ily ash. Thus, air delivered into the opening 22 circulates through the space 2I surrounding the throat portion 9 and thence upwardly into the space 20,

surrounding the retort b^ody or pot, from which i it passes through the ports I9 and I9 into the interior of the retort.,

In order to provide for the lateral distribution of air to the fuel bed above and surrounding the top of the retort, a plurality of spaced ports 25 are provided in the upper ilange-like portion II of the shell 2. As shown, the ports 25 communicate with the air space 20 within the shell 2 vertically, through the inwardly-turned portion II, and each air port 25 is provided with a roundedhood 26 which ist integral on the flange-like portion Il and which is shaped to direct air from the ports 25` radially outward from the upper end of the retort and into the surrounding bed of fuel. The several hoods project upwardly above the inturned portion II of the shell 2 and are in the nature of an angularly spaced series of bosses. Also, as shown, each of the hoods is tapered inwardly toward the axis of the retort.

As shown in Figures 6 and '1, the air ports or tuyres I8 and I9 are spaced angularly relative to`the axis of the tuyre rings and are formed by providing horizontal peripherally extending slots in the upper surface of the tuyre rings, vas by cutting away or omitting portions from the tuyre ring surface and, as shown, each port or slot extends into the ledge or shoulder formed by the inner peripheral groove at the upper margin of the tuyre ring; thus each port is stepped downwardly as shown in Figure 5, so as to clear the annular flange at the bottom of the member next above. Y.

In order to provide for equal distribution of air for combustion, the air ports or tuyres I9 of the tuyre ring 5, which is nearest to the burning fuel bed, are of varying size in the peripheral direction',v though their centers are equally spaced apart angularly, and thedisposition of the airports I9 is particularly arranged so that the largest ports are at the location of the lowest pressure in 'the air space 20 surrounding the tuyre rings.

Since the incoming air for combustion enters ythe base portion of they retort at'bne side thereof, in the direction shownv by the arrow 21 in Figs. v2 and 7, parallel to the" fore and aft'. center line, indicated by the' lin'e -A- A in Fig. 7, it will be apparent that the air pressure in the .space 20 will varyV according tothe distance from the point of entry. Hence, if the retort is considered as being divided into quadrants by the transverse center line B-B the first quadrant I will have the highest pressure and the thirdquadrant III will have the lowest pressure. IV have,a substantially equal pressure, for the reason that, in the arrangement shown, the incoming air divides in the quadrant I and passes in both clockwise and counterclockwise directions toward quadrant III.

Thus, the air ports I9 in quadrant I are made to be the smallest and the air ports in quadrant III are made to be the largest. 'I'he air ports in quadrants II and IV are substantially equal and4 are of a size intermediate the sizes for quadrants I and III. In this manner the volume of air passing through the several air ports I9 will be substantially equal for each air port around the entire periphery of the tuyre ring.

While 'such an arrangement of the air ports I 8 in the tuyre ring 4 is not shown herein, it will be understood that the air ports I 8 may be also of graduated sizes according to the quadrant in which they are located. L

In order that the tuyre rings 4 and 5 will be certain of proper angular location relative to the several quadrants, the tuyre ring 4 is keyed to the body ring 3 as at 28, Fig. 8, and the tuyre ring is keyed to the tuyre ring 4 as at 29,' the body ring 3 being keyed to the mouth of the throat portion 9 by the lug I2 as shown in Fig. 5.

As shown in Figs. 3, 5, and 8, the tuyre ring 5 is notched or grooved vertically on its outer peripheral surface, opposite each of the air ports 25 at the top of the shell 2, as indicated at 30. to provide a channel or guide to direct air from the space 20 to the air ports 25, Also in order to provide equal distribution of air to and through the air ports 25, the upper tuyre ring 5 is formed so that its upper outer peripheral edge is eccentric relative to the axis of the ring 5, as shown in Fig. 7. Thus the outermost periphery of the tuyre ring 5 is nearest the wall of the shell 2 in quadrant I and farthest from the wall of the shell 2 in the quadrant III, in this manner serving to block oil or throttle the air passing to the air ports 25 in the quadrant I, While the air ports 25 in the quadrant4 III are permitted a larger space through which air can pass from the air space 20.

. It will now be seen that the herein described arrangement, a coal-burning retort of simplified construction and lower cost of manufacture is provided; and likewise by means of the construction, an equal distribution of air to all parts of the fuel bed is accomplished automatically, regardless of the amount of air that is delivered to the wind box or air space 2|, in the base portion I, through the air supply duct 24 which is preferably connected to a motor-driven blower, not shown.

Quadrants II and I In use the improved retort is set into the ash pit of a furnace or boiler, so as to be centrallyl positioned therein. The retort is set up by first placing the base portion I and then setting thereupon the retort body ring 3 and the tuyre rings 4 and 5 after which the shell 2 is set in position and bolted down, as indicated in Fig. -l. The furnace or boiler ash pit isvthen filled in with a'suitable refractory material up to a level about one inch or an inch and a half below the hooded openings of the air ports 25; from which point the refractory material is tapered upwardly toward the side walls-of thel furnace or'looilei combustion chamber.

amasar means of a screw or worin conveyor il and upwardly therethrough into the furnace combustion chamber, Where .it `tends to dow outwardly `*toward the side walls of the same.

As the coal is supplied upwardly through-the retort from the throat portion d, air for combustion is at the same time supplied to the wind box 2i and combustion takes place at the top portion of the retort, spreading outwardly through the bed of fuel above the retorttoward the sides of the furnace combustion chamber.

Because of the equal distribution of air, accomplished by the-herein described tuyre arrangement, the fuel is ,burned uniformly about the entire periphery of the retort and the portionoi: the iuel bed lying immediately within the top portionof the retort is uniformly heated.

The hooded lateral ports l at the top of the retort serve to distribute air tothe surrounding bed of fuel and at the same time boss-like hoods ld serveto break up the solid mass or body oi thecoal as it reaches the top edgevoi the retort and is forced over the same into the space beyond or surrounding the retort. Thus, free access of air into the mass oi fuel is assured to promote uniform and complete combustion.

fuel upward through the retort in no way obstructs the hooded air ports til and while the air f ports or tuyres it and it are'feimosed to clogging by reason of sliding contact with the iuel, the fact that they are extended in a horizontal direction, instead of a vertical direction as is usually the case, tends to minimize such obstruction.

The main advantages oi my improved retort lie in the'simplicity of its construction and its readily replaceable parts as well as in the ar'- rangement providing for a more equitable dis@ tribution of combustion air to the fuel bed.

Other advantages lie in the substantially nonclogging arrangement of the air ports or tuyres opening into the interior of the retort: and in the hooded tuyre openings or air ports it v which deliver air laterally outwardly from the upper portion oi the retort, the hoods serving not only to prevent clogging oi these lateral air ports but also servingto break upthe mass of fuel as it flows over the top edge of the retort.

it will be understood, that, while the retort herein shown and described, is oi a circular construction, the invention herein set forth is equally applicable to other retort shapes such as an an upwardly extending open-ended body, a shell spaced from and surrounding said body, flangelike means connecting `the upper ends of said shell and body and closing oi the space therebetween, and a hollow support for said shell opening upwardlyinto said space and having a 1`ateral air inlet, said body having a plurality ofV perimetrically spaced ports therethrough communicating with the said space, said ports being proportioned to provide a progressively increasing port area in successive predetermined perimetrlc segments oi said body as said segments become perimetrically remote from the location oi said air inlet and a decreased port area as said 'segments again approach said air inlet location in the same 'perimetric direction.

2. A retort of the class described comprising an upwardly extending open-ended body, a shell spaced laterally froman'd surrounding said body,

lill

ange-lilre'means connectingl the upper ends of said shell and body and closing oil` the vspace therebetween, and a hollow support for said shell opening upwardly into 'said space and having a lateral air inlet, said body having a 'plurality of vertically narrow horizontally extending perimetrically spaced ports in its side wall communicating with the said space, said ports increasing in horizontal length as they progress in both perimetric directions from the side of said body adjacent said air inlet to the opposite side thereoi'.

A 3. 'A retort comprising an upwardly extending body member, a pair of horizontally disposed tuyre members fitted one upon the other .and upon the upper end of said body member, each oi said tuyre members having a plurality oi ports .perlmetrically spaced in its side wall', said ports vbeing proportioned to provide a greater port area in one side of said retort than in the opposite side thereof, a shell member spaced laterally from and surrounding said body and tuyere members, said shell member having an inwardly turned upper margin nttingly engaging the margin of the uppermost tuyre member, and

'a hollow base supporting said shell member, said base having upward communication with vthe space between said shell and bodymembers and a lateral air inlet located adjacent the side ci said retort having the smallest port openings.

d. il retort comprising an upwardly extending body member, a pair oil-horizontally disposed tuyere members fitted one upon the other and upon the upper end of said body member, each of sel said tuyere vmembers having a plurality or" ports perirnetrically spaced in its side wall;v said ports being proportioned to provide a progressively increasing portarea in successive predetermined perimetric segments oi' said retort which segments progress in both perimetric directions from one side oi said retort to the opposite side thereof, a shell member spaced from and surrounding said body and tuyere members, said shell member having an inwardly turned upper margin flttingly engaging the margin oi the uppermost tuyre membei', and a hollow' base supporting said shell member, said base having upward communication with the space between said shell and body members and a; lateral air inlet `located adjacent the side oi said retort having the smallest port openings.

5. A retort of the class described comprising an upwardly extending open-ended body, a shell spaced from and surrounding said body, dangelihe means connecting the upper margins of said shell and said body, and a plurality of hollow perimetricallyspaced bosses projecting upwardly from the upper surface of said flange-like means, said hollow. bosses each having communication with the space between said shell and body and Y laterally outbill upwardly extending open-ended body, a shell spaced from and surrounding said body, iiangelike means connecting the upper margins of said shell and said body, and a plurality of hollow inwardly tapered perimetrically spaced bosses projecting upwardly from said flange-like means, said bosses each having a port opening laterally outward relative to said shell, and said dangelike means having spaced ports providing communication between said hollow bosses and the space between said shell and body. 4

7. A retort of the class described comprising an upwardly extending open-ended body, a shell spaced laterally from and surrounding, said body, means connecting the top of said shell and the upper margin oir said body. said last-named means having a plurality of perimetrically spaced ports communicating with the space between said shell and said body, a hood covering each of said ports and opening laterally outward relative to said shell, said body and shell being arranged to provide a progressively increasing width of the space between their respective side walls and in the vicinity of said ports in both perimetric directions from one side of said retort to the opposite side thereof. K

. 8. A retort comprising an annular open-ended upwardly extending body member, a pair of an- `nular tuyre rings fitted one upon the other and upon the upper end of said body member, each of said tuyre rings having a plurality of angularly spaced tuyres opening through its side wall, said tuyres being arranged to provide a progressively increasing tuyre opening area in successive predetermined angular segments of said retort in both angular directions from one side of said retort to the opposite side thereof, an annular shell member spaced from and surrounding said body member and tuyre rings, means connecting the margins of said shell and the uppermost tuyre ring to close oit' the space therebetween, and a plurality of angularly spaced hollow bosses projecting upwardly from said last-named means, said bosses having communication with the space between said shell and tuyre rings and a port opening radially outward relative to said retort.

9. A retort comprising an annular open-ended upwardly extending body member, a pair of annular tuyre rings iitted one upon the other and upon the upper end of said body member, each of said tuyre rings having a plurality of angularly spaced tuyres opening through its side wall, said tuyres being arranged to provide a progressively increasing tuyre opening area in successive predetermined angular segments of said retort in both angular directions from one side of said retort to the opposite side thereof, an annular shell member spaced from and surrounding said body member and tuyre rings, means connecting the margins of said shell and the uppermost tuyre ring to close off the space therebetween, said lastnamed means having a plurality oi angularly spacedV openings therethrough communicating with the said closed olf space each covered by a vertically projecting hood-like boss, said bosses each having a port opening radially outward from said retort, and the uppermost tuyre ring having its outer margin eccentric relative to the inner wall of said shell to throttle certain of said lastnamed openings.

10. In a device of the class described, a tuyre member comprising an annular ring having a plurality of angularly spaced horizontally extending slot--like tuyre openings in its side wall and an outei` periphery eccentric relative to its inner periphery, said tuyre openings being of varying length as they progress angularly about, said ring from the place of greatest eccentricity of said peripheries.

11. In a device of the class described, a ringlike tuyre member having a plurality of tuyre openings spaced along its side wall, said tilyre member being formed with the center of the area defined by its outer perimeter offset laterally relative to the center of the area defined by the inner periphery.

12. In a device of the class described, a tuyre member comprising an annular ring having a plurality of angularly spaced tuyre openings in its sidewall, said tuyre member being formed with its outer periphery eccentric relative to its inner periphery.

13. A retort of the class described, comprising an inwardly extending open-ended body, a shell spaced laterally from and surrounding said body, means connecting the top oi' said shell and the upper margin of said body, said last-named means having a plurality of laterally opening perimetrically spaced ports communicating with the space between said shell and saidy body, and said body and shell being arranged to provide a progressively increasing width of the space between their respective sidewalls and in the vicinity of said ports in both perimetric directions from one side of said retort to the opposite side thereof.

14. A-retort of the class described, comprising an inwardly extending open-endedbody, a shell spaced laterally from and concentrically surrounding said body, means connecting the top of said shell and the upper margin of said body, said last-named means having a plurality o1' perimet- ,rically spaced ports communicating with the JOHN C. BOHMIKER.

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