US2205596A - Stoker - Google Patents

Description

N. M. LOWER June 25, 1940.

STOKER Filed April 22, 1957 2 Sheets-Sheet l INVENTOR. than .M Lowe/1 ATTORNEY .5:

N. M. LOWER 2,205,596

STOKER Filed April 22, 1937 Juize 25, 1940.

2 Sheets-Sheet 2 INVENTOR. Nazi/zam M Loa/en BY W www ATTORNEYS.

Patented June 25, 1940 UNITED STATES PATENT OFFICE My invention relates to improvements in furnaces and has for its main object the provision of an improved automatic furnace including automatic fuel feeding, grate shaking and ash remov- 'g ing means.

A more speciiic ob-ject of the invention is to provide an `improved stoker mechanism for delivering fuel to'a furnace having a plurality of fuel feed openings.

Another object of the invention is to provide -la fuel feed conduit, having a screw conveyor for advancing fuel therethrough, with a discharge vopening in its lower wall portion so formed that fuel will drop therethrough in a stream spreading lengthwise of the conduit.

A further object of the invention is to provide a stoker, having a conduit leading from a Source of fuel supply and laterally extendingbranches delivering to a plurality of openings in the furnace, with means for conveying fuel through the branches and varying the relative amounts of fuel delivered by the branches.

A further object of the invention is yto provide a furnace with a novel door for the firing opening of the furnace and a novel combination and.Y arrangement thereof with the delivery end o-f a Stoker adapted to feed fuel through thefring opening. o

With the above and other objects in view, the invention consists of the novel details of construc,

tion, and the novel combination and relation of parts, he-reinafter more fully described and` illus,-` trated in the accompanying drawings, wherein: Fig. 1 is a vertical longitudinal section through a portion of a furnace room and a furnace, -with Stoker, grate shaking and ash conveying mechanism applied to the furnace and vshownxpartly in section and partly in elevation;

Fig. 2 is a sectional view taken on the line `2.-'-2 of Fig. 1;

Fig. 3 is a fragmentary view of the furnacefron'r within showing the firing openings with the novel stoker mechanism applied thereto and shown partly in section and partly in elevation;

Fig. 4 is a fragmentary sectional view taken on the line 4-4 of Fig. 3; and

Fig. 5 is. a fragmentary sectional view taken on the line i'a--B of Fig. 3.

ing at each side of a vertical plane passing throughv the longitudinal center of the furnace front I2. The openings I3 are provided withthe doors I4 hinged to the furnace front, as at I5, to swing lati provided with air admission. openings Illa. The rebox II is provided with a grate I6, beneath which is a pit I1= for receiving ash, formed in the furnace room vdoor I8.

Fuel is delivered to the furnace from a suitable source of-supply (not shown) by a mechanical stoker, designated generally by the letter S. 'I'he Stoker comprises a plurality of end to end related conduits, including a horizontally extending conduit I9 leading from the source of fuel supplyf and preferably disposed in a depression in the furnace room fioor I8, and a `riser conduit `2l l comprising a `plurality of Vsections at successively greater angles Withrespect to the horizontal. In this manner the path of the fuel is changed fom a horizontal 'to an almost vertical direction' through.` a series of moderate angles, thereby' avoiding any abrupt bends in the conduit system.

The riser conduit 2l is shownfn the drawings as comprising three sections, but it will be apparent that the number of-sections and the angularity therebetween may be altered to suit the requirements of the particular installation. The riser conduit 2lI extends in a general ,forward and up# Ward direction from the horizontal conduit I9 to av pointadjacent .the furnace lfront I2, between the fire door openings I3 andat about the level- Fuel is of` the upper marginaLedges thereof. y advanced. through thecondui'ts I9 and 2i by screw .conveying means y22,A formed of a pluralityof sections universallyconnected adjacent the bends between the conduit sections.k o

' A'conduit 423 extends I,horizontally alongthe furnace front I2 immediately above the level of ther upper marginal edge'of the firing openings I3.

Intermediate: its ends, the conduit 23 is provided with a downwardly opening spout 24 communicatingwiththe upper end of the riser conduit 2 I The conduit 23 is open at one end, as indicated in Fig. 3 at 25, and a- -removable cover plate 26 formsv a closure therefor. I

A horizontal telescopic shaft 21 extends through they condruit 23 `and comprises a short shaft section 28 journaled in a bearing 29. formed in the end .wall 3l! of the conduit 23, and a long shaft section 3| journaled ina bearing 32 formed inl the. cover plate 26. Theglong shaftsection 3I is provided with a ysquared end 33 arranged to ybe received in a square opening 34 in theshort shaft: section- 28, thereby permitting relative longitudi' nalmovement between the shaft sections28 and 3|,1sothat'the shaft section 3| can be removed.- frorn the conduit 23 through its open end 25,l and also' preventing relative rotational-.motion between the shaft sections 28 and 3| The long shaft section 3| `is provided with the oppositely wound helicoid conveyors 35 and 35a, at each side of the spout 24.

The helicoid conveyors 35 and 35a terminate short of the ends of the conduit 23 and between the ends of the conduit 23 and the ends of the helicoid conveyors 35 and 35a, the conduit 23 is provided with the discharge openings 36. Formed with the conduit 23 and embracing the openings 36 are chutes 31 that extend downwardly and inwardly from the conduit 23 toward the firing openings I 3. The doors I4 are bulged outwardly as best shown in Figures 1, 3 and 4, at 3B, and secured to the inner side of the sloping Walls`39- thereof are the nozzles 4|). The bulged portions 3B of the doors I4 open upwardly and receive the lower ends of the chutes 31. The openlower ends of the chutes 31 are in registering communication with the open upper ends of the nozzles 4|) and are spaced a slight distanceapart so that the doors I4 may be swung open.

The nozzles 46, as best illustrated in Figures 3 and 5, flare laterally and the inner surfaces of the sloping rear walls 4I of the nozzles 40 are flat. When the conveyor screws of the Stoker are operating to advance fuel throughtheconduit system, fuel drops by gravity through the discharge openings 36 of the conduit 23 into the chutes 31 and thence onto the sloping rear walls 4| of the nozzles 43, along which it descends .andi discharges from the bottom of the nozzles.

The openings 36 in the conduit 23 are so designed that the fuel will spill therethrough in a ribbon-like stream spreading laterally across the surface of the` rear, walls 4| of the nozzles 4D. The edges 42 of the openings 36 over which the fuel spills are formed on a diagonal, providing helical spill edges extending circumferentially of the conduit 23, see Figures 3, 4 and5, so that the fuel dropping through ther openings 36 is spread out lengthwise of the conduit 23.

It is known that a helicoid4 screw will convey more fuel along one side of a conduit than the other. With the4 nights of the helicoid conveyors 35 and 35d wound in the directions as shownin Fig. 3 and. thedirection of rotation of. the conveyors as indicated in the same figure by the arrows, fuel will be conveyed toward the openings 36, most of it being carriedalong that side of the conduit 23 farthest from the furnace front l2. Now, since most of the fuel is carried along that side of the conduit 23 .farthest from the furnace front l2, the spill edges 42 of the conduit 23 at the openings 36 must be ona diagonal extending from that side of the conduit 23A nearest the furnace front I2 and nearest the helicoid conveyors 35 and 35a to that side ofy the conduit 23.1nore remote from the furnace front I2 and more remote from the helicoid conveyors 35 and 35a, so that the fuel will spread lengthwise of the conduit 23 in dropping through theopenings 36.

On the sloping rear walls 4I ofthe nozzles` 40 are mounted the wedgefshaped deectingvanes 43, two being shown in each of the nozzles. The vanes 43 spread the fuel laterally and are preferably made adjustable to vary the amount of fuel on different areas of the rear walls 4I. For ease and convenience in adjusting the vanes 43, stems 44, extend through the doors I4. and the nozzle rear walls 4I and are threaded at one end into the vanes 43 and at their other ends, exterior of the doors I4,- are provided with the handles 45.

As` explained above, the fuel drops onto the`v nozzle rear walls 4I yin a laterally spread stream and as it passes down along the sloping surfaces of the rear walls 4I, it is further spread by the deector vanes 43. The fuel falls from the noz-- 'zles 4I) onto the rearward portion of the fuel distributor plates 46 which are mounted in the lower portion of the firing openings I3. At the rear of the distributor plates 46 and beneath the nozzle rear walls 4|' are located the fluid pressure distributor heads 41, provided with jet openings 48 directed across the plates 46 and from which issue pressure fluid blasts for projecting fuel across the plates 46 into the rebox. The top surfaces of the plates 46 are provided with longltudinally extending ribs 43 dii/erging slightly as they extend forward.

The two end ribs on each of the plates 46 are provided with adjustable outwardly curving end portions 50. The end portions 56 are mounted on pins 5| for pivotal movement in the plane of the top surface of the plates 46. The pins 5| project beneath the surface of the plates 46, and on the projecting portions thereof are mounted the arms 52 which in turn are movably connected at their free ends with links 53 that extend rearwardly through the recesses 54 in the lower edge of the re doors I4. I-Iandwheels 55 threaded on the exteriorly projecting ends of the links 53 are provided for adjusting the movable vane portions 5D to control the delivery of fuel to the corners of the firebox adjacent the furnace front I2.

The Stoker conveyor screws are operated by a motor 56, shown in dotted lines in Figure l. A gear box 51 is secured in any suitable manner to the horizontal conduit I9 and is provided with a bracket 58 for supporting the motor 56.

The helicoid conveyors 35 and 35a are operated from the motor 56 through the Stoker conveyor screw 22 in the manner now to `be' described. An extension |30 of the shaft of the conveyor screw 22 projects through the horizontal conduit 23 and has secured thereon a bevel gear |3|. The bevel gear I3| meshes with a bevel gear |32 secured on one end of a shaft |33, which is journaled in bearings |34 and |35, preferably formed with the horizontal conduit 23. The shaft |33 extends from a point adjacent the projecting Ashaft extension |30 to a point adjacent and exterior of the closed end 36 of the conduit 23. That end of the shaft |33 adjacent the closed end 30 of the conduit 23 has secured thereon a spur gear |36 meshing with a gear |31 which is secured on that end of the shaft section 28 pro jecting exteriorly of the conduit 23. Motion is thus imparted to the shaft section 28 by the conveyor screw 22 through the systems of shafts and gears described, and consequently to the helicoid conveyors 35 and 35a, through the operative connection between the shaft sections 28 and 3|.

The helicoid conveyors 35 and 35a. are arranged to be shifted axially of the conduit 23, so that one of them will receive and convey more of the fuel delivered through the chute 24 by the stoker conveyor screw 22 than the other of said conveyors. The shifting of these helicoid conveyors is Yaccomplished through a shifter lever |38 pivotally mounted intermediate its ends on a support member |39 formed with the cover 26 of the conduit23. An arm |46) of theshifter lever |38 is pivotally connected with rod I4I, threaded at its free end and passing through an opening |42 in an extension |43 of the cover 26. By turning nuts |44, threaded on the free end of the rod |4I, the shifter lever I 38 is caused to-move about its pivot. The other arm of the shifter lever |38 is provided at its free end with a toothed quadrant |46 which engages the serrated member |41 keyed on an extension of the shaft 3 I. It is clear then, that by turning the nuts |44, the shifter lever |38 turns about its pivot, moving the toothed quadrant |46 which, by reason of its engagement with member |41, shifts the shaft 3| and consequently shifts the helicoid conveyors 35and 35a axially of the conduit 23.

l'-Ash is conveyed from the pit I'I by theash conveyor screw 86 to the base of an upright casing 89 which extends upwardly to a point above the level of the furnace room floor I8.l The casing 89 communicates at its upper end with a casing 90 extending horizontally along the furnace front I2 to one side thereof and opens downwardly into the ash receptacle 9|. The ash conveyor screw 86 is operated by the motor 56 through the sprocket chain 84 and shaft 88.

The-grates `I6 are shaken by the motor `56 through a crank and lever arrangement including a rod |08 operatively connected at one end with the grates I6 and pivotally connected at its other end intermediate the ends of a lever IIIJ, which is pivotally mounted at one end in any suit-able manner to the furnace front I2. A'rod ||2 is pivotally connected at one end to the free end of the lever I I0 and pivotally connected at its other end to the free end of a` crank arm ||3 which in turn is operatively connected to the motor 56. l

I claim:

1. The combination with a material receiving chamber having a wall provided with an opening, of mechanism comprising a device at said opening for feeding material into the chamber, a feed conduit extending transversely along said wall and having its delivery end above said feed device, said feed conduit being provided at its delivery end with a discharge opening communieating with said feed device, said discharge openingbeing formed to provide a helicoid spill edge extending circumferentially of the conduit wherevby material will drop over said spill edge to said feed device in a stream` spreading lengthwise of the conduit.

2. 'Ihe combination with a material receiving chamber, of feeding mechanism comprising a pair of laterally spaced devices for feeding material into the chamber, ka feed conduit above the level of said feeding devices, said feed conduit having a discharge opening in the lower half thereof adjacent each of its ends communieating with a respective feed device and a receiving opening between said discharge openings,

means in said feed conduit for conveying ma ,terial toward said discharge openings, each of said discharge openings being formed to pro- Ivide a helicoid spill edge extending circumferentially of the conduit whereby material will drop over said spill edge to 'said feed devices in a stream spreading lengthwise of the conduit.

3. 'Ihe combination with a material receiving chamber, of feeding mechanism comprising a pair of laterally spaced devices for feeding material into the chamber, a feed conduit above the level of said feeding devices, said feed conduit having a discharge opening in the lower half 'thereof adjacent each of its ends communicating with a respective feed device anda receiving opening between said discharge openings, screw conveying means in said feed conduit at each side of said` receiving opening for conveying material to said discharge openings, each of said discharge openings being formed to provide a helicoid spill edge extending circumferentially of the conduit, the portion of said spilledg'e on that side of the conduity along which mostof the material is conveyed being more remote from the end of the-screw conveyor than the portion of said spill edge on the other side of said conduit whereby material will drop over saidspill edge to said feed devices in a stream spreading lengthwise of the conduit. I

4. In a furnace provided with a rebox and an upright wall having a pair of laterally spaced openings therein, a door for each of said openings, each of said doors having a bulging upper central portion, the bulgingportion of said doors opening upwardly exteriorly of the furnace, a fuel feed conduit extending horizontally along said furnace wall immediatelyv above the level ol Vthe upper marginal edge of said openings, said fuel feed conduit having a discharge opening in thelower half thereof adjacent each of its ends communicating with the open upper end' of the bulged portion of a respective door, each of the discharge openings in said conduit being formed to provide a helicoid spill edge extending circumferentially of the conduit whereby fuel will spill over said spill edges into said bulging door portion in streams spreading lengthwise of the conduit, and means in said fuel feed conduit for conveying fuel toward said discharge openings.

5. In a furnace provided with a iirebox and an upright wall havinga pair of laterally spaced openings therein, a door for each of said openings, each of said doors having a bulging upper central portion, the bulging portion of said doors opening upwardly vexteriorly of the furnace, a fuel feed conduit extending horizontally along said furnace wall immediately above the level of the upper marginal edge of said openings, said fuel feed conduit having a discharge opening in the lower half thereof adjacent each of its ends communicating with the open upper end of the bulged portion of a respective door, each of the discharge openings in said conduit being formed to provide a helicoid spill edge extending clrcumferentially of the conduit whereby fuel will spill over said spill edges into said bulging door portion in streams spreading lengthwise of the conduit, screw conveying means in said fuel feed 'conduit conveying fuel to each of said discharge openings and means for shifting said conveying means axially of said conduit for varying the relative amounts of fuel delivered to each of said discharge openings.

6. In a furnace provided with a firebox and an upright wall having a pair of laterally spaced openings therein, a door for each of said openings, each of said doors having a bulging upper central portion, the bulging portion of said doors opening upwardly exteriorly of the furnace, a nozzle mounted in the bulged portion of said door, saidnozle being open at its respective upper and lower ends, a fuel feed conduit extending horizontally along said furnace wall immediately 'above the level of the upper marginal edge lof said openings, said fuel feed conduit having a discharge opening in the lower half thereof adjacent each of its ends and above the open upper i upper endsof said nozzles, each of the discharge openings in said conduit being formed to provide a helicoid spill edge extending circumferentially of the conduit whereby fuel will spill over said spill edges into said nozzles in streams spreading lengthwise of the conduit, means in said fuel feed conduit for conveying fuel toward said discharge openings and a fuel distributing plate in each of said ring openings receiving fuel from said nozzles.

7. A feeding device including a tubular conduit, said conduit having a pair of spaced material discharge openings and a material receiving opening between said discharge openings, means in said conduit between said receiving opening and each of said discharge openings for conveying material toward said discharge openings, and means for shifting said conveying means axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

S. A feeding device including a tubular conduit, said conduit having a pair of spaced material discharge openings and a material receiving opening between said discharge openings, screw conveying means in said conduit between said receiving opening and each ofsaid discharge openings for conveying material toward said discharge openings, and means for shifting said screw conveying means axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

9. A feeding device including a tubular conduit, said conduit having a pair of spaced material discharge openings and a material receiving opening between said discharge openings, a screw conveyor including a shaft extending longitudinally through said conduit, oppositely wound screw flights on said shaft between said receiving opening and each of said discharge openings for conveying material from said receiving opening tc each of said discharge openings, and means operatively connected with said screw conveyor shaft for shifting the conveyor axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

10. A feeding device including a tubular con, duit, said conduit having a pair of spaced material discharge openings and a material receiving opening between said discharge openings, means in said conduit between said receiving opening and each of said discharge openings for conveying material toward said discharge openings, drive mechanism at one end of said conduitoperatively connected with said conveying means and means at the other end of said conduit forshifting said conveying means axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

ll. A feeding device including a tubular conduit, said conduit having a pair of spaced material .discharge openings and a material receiving opening between said discharge openings, a screw conveyor including a shaft extending longitudinally through said conduit, oppositely wound screw flights on said shaft between said receiving opening and each of said discharge openings for conveying material from said receiving opening to each ofV said discharge openings, drive mechanism operatively connected with one end of said screw conveyor shaft and meansl operatively connected with the other end of said screw conveyor shaft for shifting said screw conveyor axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

12. A feeding device including a tubular conduit, said conduit having a pair of spaced material discharge openings and a material receiving opening between said discharge openings, and means in said conduit between said receiving opening and each of said discharge openings for conveying material toward said discharge openings, each of said discharge openings being formed to provide a helicoid spill edge extending circumfcrcntially of the conduit whereby material will drop over said spill edges through said discharge openings in streams spreading lengthwise of the conduit.

i3. A feeding device including a tubular conduit, said conduit having a pair of spaced material discharge openings and a material receiving lopening between said discharge openings, means in said conduit between said receiving opening and each of said discharge openings for conveying material toward said discharge openings, each of said discharge openings being formed to provide a helicoid spill edge extending circumferentially of the conduit whereby material will drop over said spill edges through said discharge openings in streams spreading lengthwise of the conduit, and means for shifting said conveying means axially of said conduit to any one of a nurnber of positions for varying the relative amounts of material conveyed to each of said discharge openings.

14. A feeding device including a horizontally disposed tubular conduit, said conduit having a pair of spaced material discharge openings in the lower portion thereof and a material receiving opening between said discharge openings, and screw conveying means in said conduit between said receiving opening and each of said discharge openings, each of said discharge openings being formed to provide a helicoid spill edge extending circumferentially of the conduit, the portion of said spill edges on that side of the conduit along which most of the material is conveyed being more remote from the end of the screw conveying means than the portion of said spill edges on the other side of said conduit whereby material will drop over said spill edges through said discharge openings in streams spreading lengthwise of the conduit.

15. A feeding device including a horizontally disposed tubular conduit, said conduit having a pair of spaced material discharge openings in the lower portion thereof and a` material receiving opening between said discharge openings, screw conveying means in said conduit between said receiving opening and each of said discharge openings, each of said discharge openings being formed to provide a helicoid spill edge extending circumferentially of the conduit, the portion of said spill edges on that side of the conduit along which most of the material is conveyed being more remote from the end of the screw conveying means than the portion of said spill edges on the other side of said conduit whereby material will drop over said spill edges through said dis'- charge openings in streams spreading lengthwise of the conduit, and means for shifting said screw conveying means axially of said conduit to any one of a number of positions for varying the relative amounts of material conveyed to each of said discharge openings.

16. A feeding device including a tubular conduit, said conduit having a material discharge opening and a material receiving opening and means in said conduit between said receiving opening and said discharge opening for conveying material toward said discharge opening, said discharge opening being formed to provide a helicoid spill edge extending circumferentially of the conduit whereby material will drop over said spill edge through said discharge opening in a stream spreading lengthwise of the conduit.

17. A feeding device including a tubular conduit, said conduit having a material discharge opening and a material receiving opening, and

screw conveying means in said conduit between said receiving opening and said discharge opening for conveying material toward said discharge opening, said discharge opening being formed to provide a helicoid spill edge extending circumferentiallyl of the conduit, the portion of said spill edge on that side of the conduit along which most of the material is conveyed being more remote from the end of the screw conveying means than the portion of said spill edge on the other side of said conduit whereby material will drop over said spill edge through said discharge opening in a stream spreading lengthwise of the conduit.

NATHAN M. LOWER.

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