US2937771A - Layer loader - Google Patents

Description

A. J. STOCK LAYER LOADER May 24, 1960 s Sheets-Shet 1 Filed Aug. 15, 1958 l numn INVENTOR ATTORNEYS A. J. STOCK LAYER LOADER May 24, 1960 8 Sheets-Sheet. 2

Filed Aug. 15, 1958 INV ENTOR Arthur J .Sfoc/r ATTORNEYS A. J. STOCK LAYER LOADER May 24, 1960 Filed Aug. 15, 1958 8 Sheets-Sheet. 3

FIG. 5

FIG. 6

IN VENTOR Arthur J Stock Jam, mm, w Min ATTORNEYS y 24, 1950 A. J. STOCK 2,937,771

' LAYER LOADER Filed 1958 8 Sheets-Sheet 4 Q YINVENTOR r 7 Arf/wr J Slack :3 BY WWWZIMWMWL ATTORNEYS 1950 A. J. STOCK 2,937,771

LAYER LOADER Filed Aug. 15, 1958 8'Sheets-Sheet 5 INVENTOR Arthur J Sfoc/r BYJW, a pm, w M

ATTORNEYS May 24, 1960 A. J. sTocK 2,937,771

' LAYER LOADER Filed Aug. 15, 1958 8 Sheets-Sheet 6 IN VENTOR 9 Anhur J Sfoc/r dm Wm, m WMM ATTORNEYS May 24, 1960 A. J. STOCK 2,

LAYER LOADER Filed Aug. 15, 1958 8 Sheets' Sheet '7 FIG. 10

INVENTOR Arfhur J Slack ATTORNEYS y 4, 1960 A. J. STOCK 2,937,771

LAYER LOADER Filed Augi 5. 8 a Sheets-Sheet 8 FIG. ll

FIG. 12

INVENTOR Arthur J .Sfoc/r ATTORNEYS United States Patent The present invention relates to a means for feeding solid particulate or granular material from one or more supply points to one use or more locations of use.. More particularly, the present invention is capable of receiving the material from an essentially point source of supply and spreading or distributing the same over an elongated surface area at the location of use. As will hereinafter appear, the feeding means of the present invention is particularly advantageous from the standpoint of segregation. v

Briefly stated, segregation, as it applies to solid particulate material, refers to a condition where the larger particles of a given mass of the material tend to become separated from the smaller particles of the material. In many systems and processes, it is desirable to prevent or eliminate segregation such that the solid particulate material will be supplied as a substantially uniform mixture of smaller and larger particles.

The feeding means of the present invention has two distinct advantages from the standpoint of segregation:

First of all, the present device is inherently not segregating; that is, the feeding means itself does not tend in its normal operation to separate the larger particles of the feed from the smaller particles thereof;

Secondly, the feeding means will tend to eliminate any preexisting condition of segregation in the material supplied to the feeding means.

More specifically, the present invention relates to a means for feeding coal to the hopper of a stoker for a boiler. The characteristics of the stoker, in this instance, are such that coal must be supplied to the stoker hopper in a non-segregated condition in order that combustion will take place efiiciently.

The feeding means of the present invention includes a substantially vertical receptacle, open at its top and bottom ends, and movable in a horizontal path over the top of the stoker hopper. At certain positions during its cycle of movement over the top of the stoker hopper (or, in one modification, to the side of the stoker hopper), the movable receptacle is located directly below a point of supply. At each of these positions, a downspout, which represents the point of supply, is provided with a movable gate which is opened or closed in response to the movement of the receptacle towards or away from the downspout, respectively. The movable receptacle is caused to move back and forth across the top of the stoker hopper, receiving coal from the downspout during such times as it is positioned beneath the same, and spreading this coal on the upper surface of the coal already in the hopper. Naturally, the amount of coal distributed or spread by the receptacle will be commensurate with the consumption of coal in the boiler. In passing over the upper surface of the coal in the hopper, the movable receptacle deposits a relatively thin layer of coal upon this upper surface; the effect of this distribution is such that the coal particles, in passing out from under the edge of the movable receptacle, become mutually intermixed so as to form a non-segregated layer.

The prior art has long since recognized the problem of segregation. In some instances, the nature of the coal ice handling equipment, including elevators, bunkers, silos and downspouts, was such as to create a certain amount of segregation. Heretofore, the only satisfactory means capable of compensating for such segregation has been the so-called swinging spout-which, of course, is also employed for distributing coal over the elongated surface of a stoker hopper.

Although the swinging spout will generally compensate for this segregation, nevertheless, there are two rather serious disadvantages to be encountered in its employment:

First of all, the swinging spout requires a relatively large amount of headroom for its installation and operation. (It might be mentioned that adequate headroom may not be available or may require additional construetion expense for its provision.)

Secondly, the swinging spout is so cumbersome and space-consuming, that it cannot readily be enclosed in a dust-tight housing where it might be desirable in many instances to do so.

Thus, it is an important object of the present invention to provide a means for feeding solid particulate material from one or more points of supply to an elongated zone of use.

Another important object of this invention is to provide a feeding means of the type referred to above which will distribute the material in an essentially non-segregated condition.

It is another important object of the present invention to provide a device of the type referred to above which requires [a minimum amount of headroom. 1,

Another important object of the present invention is to provide a device of the type referred to above which, in addition to its function of distributing the material along the area of use, is also capable of conveying the material to this area from a supply inlet which is horizontally offset therefrom.

,It is a still further important object of the present invention to provide a device of the type referred to above. which may be readily enclosed in a dust-tight housing.

Another object ofthe present invention is to provide a device of the type referred to above which is completely automatic. i I

Another object of the present invention is to provide a device of the type referred to above which is relatively simple to construct and install.

Another object of the present invention is to provide a-device of the type referred to above which is easy to maintain and which is reliable in operation.

Other and further objects and advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:

Figure 1 is a semi-diagrammatic view in side elevation showing the relationship between a downspout, a stoker hopper, a portion of a horizontally movable grate, a front wall of a boiler, a movable receptaclefor feeding coal from the downspout to the stoker hopper, and. a gate for the downspout; V I

Figure 2 is a semi-diagrammatic front elevation ofthe elements shown in Figure 1, with the receptacle being positioned in its coalereceiving location directly below the centrally located downspout; 1 Figure 3 is a view similar to Figure 2 showingthe relative positions of the downspout, the gate for closing the same, the movable receptacle, and the coal deposited by the movable receptacle'after the latter has been moved towards the right from the position indicated in Figure'2;

Figure 4 is a view similar to Figure 3 showing the relative positions of the various components after the receptacle has reached its extreme right-hand position and has commenced movement towards the left. 'l

Figure is a view similar to Figure 2 wherein two inlets or downspouts are employed;

Figure 6 is a view similar to Figure 2 wherein the inlet or downspout is horizontally offset from one side end of the stoker hopper;

Figure 7 is a front view of one modification of the present invention, with a portion of the housing broken away and with some parts in section, showing the details of the movable receptacle, the downspout, the gate for the downspout, the means on the receptacle for actuating the gate, and the means for supporting the movable re- -ceptacle;

Figure 8 is a front elevation, partly in section, showing on a larger scale the details of the movable receptacle and associated structure;

Figure 9 is a left-hand side view taken fromFigure 8 showing further details of .the movable receptacle in conthe various pulleys and cables employed for moving the .receptacle back and forth;

Figure 12 is a semi-diagrammatic front view showing a modified form of the present invention.

In the detailed description which follows, it will be observed that the present invention is explained in terms of a coal-handling device for the stoker of a boiler, consistent with the illustrations in the attached drawings. However, it should be understood'that the present invention might be employed for feeding other granular material from a point source of supply to an elongated area ofuse in a non-segregated condition.

Further, it will be noted that the nature of the present invention is such that coal is spread (or loaded) in the .form of layers across'the stoker hopper. For this-reason the present invention, as the title indicates, is referred to .as a "layer loader.

Referring to the drawings in detail, in Figures 1 and 2 there is shown a downspout 1 which is continuously filled with coal from a supply of the same suchas a bunker or silo (not shown). As shown in Figure 2, the coal from the downspout passes through an opening 2 in the gate 3 andinto the interior of a receptacle 4, which is open at its upper and lower ends. The receptacle 4, in turn,.dis-

charges coal onto the upper surface of an existing .quantityofcoal 5 whichsubstantially fillsthe stokerhopper 6. 'Thestoker hopper 6 at its lower end feeds the coal onto the upper surface of a horizontally moving grate 7; the latter carries a layer of coal into the interior of the boiler, the front wall of which is designated by the reference character 8. The portion of the device extending above the level of the stoker hopper 6 is the housing 9 which .surrounds the movable receptacle 4 so as to make the feeding system entirely dust-tight.

The operation of the present invention will now be described briefly with particular reference to Figures 2, 3,

and 4. In Figure 2, the movable receptacle 4 is positioned directly below the downspout 1. The gate 3 is so positioned that the opening 2 .is in alignment with the .lower end of the downspout and the upper opening of the receptacle such that the receptacle will -be completely filled with coal. It will be assumed that the receptacle 4 is being ,pulled in a direction indicated .by thearrow A by a drive means which will be described hereinafter in .greater detail. Also, 'as will hereinafter appear in con- "nection with a detailed description'of-Figures'l, 8, and 9,

the movable receptacle '4 is provided with azmeans for 3 and 4.

.plate 10 serves to complete the dust-tight closure at that As the receptacle 4 moves in the direction indicated by the arrow B in Figure 3, coal will be deposited or discharged in the form of a layer on the upper surface of the body of coal 5; the discharge of coal from the receptacle, taken in consideration with the consumption of coal in the boiler will be such that the upper surface of the body of coal 5 will slope gradually upwardly from the left to the right as it appears in Figure 3. When the receptacle 4 is moving in the opposite direction, the upper surface of the body of coal '5 will be sloped in the opposite direction. -In Figure 3 the receptacle 4 has moved, together with the gate 3, to such a position that the downspout -1 is'completelyclosed off by the left-hand portion of the gate.

In Figure 4, the receptacle 4 has moved to the extreme right-hand end of the housing 9 and is now commencing to move in the opposite direction as indicated by the arrow C. It should be pointed out that the receptacle 4, in

.moving beyond the position indicated in Figure 3, be- :comes disengaged entirely from the gate '3 such that the :gate remainsin the position shown in Figure 3 until the receptacle 4 moves in the opposite direction a .sufiicient amount to re-engage the gate and move the .same in the direction indicated by the arrow C. From the position shown in Figure 4, the receptacle moves toward the left .(in the direction of the arrow .0) until, at the time point when the receptacle 4 is positioned belowthe downspout .1, another quantity of coal is fed into the receptacle through the opening 2 in the gate 3. Continued movement of the receptacle 4 towards the left from this position will .cause the right-hand end-of the gate 3 toclose off the lower .end of the downspout 1. The operation above described will continue repeatedly as the receptacle 4 moves back and .forth .across the length of the striker hopper 6.

vAs shownin Figure 5, the housing 9a for the movable receptacle 4 is provided with two inlets 1a and 11:.

-are located adjacent the ends of the housing 9a. Of

course, if these two inlets .are spaced inwardly .from the ends of the housing, then the gates for closing these inlets would .be substantially the :same as the gate shown .in Figures.2-4, inclusive.

Figure 6 illustrates a condition where a supply inlet .10 is horizontally spaced to the left and above the stoker hopper 6. The housing 9b for the receptacle 4 also extends toward the left and, further, is provided with n fiat-plate .10 at the bottom of this extension. The flat end of-the housingand also provides a flat surface over which the lower end of the receptacle 4 will slide during its movement to or from a loading position beneath the downspout 1 and its passage into or out of the space over the stoker hopper 6. Thus, the receptacle 4 will slide over the surface of the plate 10 without losing any of its coal until it reaches 'a position above the stoker hopper 6.

With regard to Figures 5 and 6 the spreading action of the coal will be substantially the same as that described with reference to Figures 2, 3, and 4.

Referring to Figures 7, 8, and -9 the receptacle 4 is mounted for horizontal sliding (or rolling) movement on a pair of spaced parallel rails or tracks 20 and 21. A bracket 22 is mounted at each of the four corners of the receptacle 4; each of the brackets has journaled therein an upper vertical wheel 23, a lower vertical wheel 24,.and an intermediate horizontal .wheel (25. .The upper wheels 23 rest on the upper surfaces of the rails 20 and 21 and thus carry the weight of the receptacle 4. The lower wheels 24 are spaced slightly below the bottoms of the rails, serving to limitthe upward movement of the receptacle. due to any unusual load conditions that might be present. The horizontal wheels 25 are slightly spaced from the opposed inner surfaces of the rails 20 and 21 and serve to insure lateral stability of the movable receptacle. Inasmuch as the receptacle 4 is constructed of relatively thin material, a supporting strip of metal extends around the outside of the receptacle, as indicated by the reference character 26. The four brackets 22 are actually attached to this metal strip 26 rather than directly to the receptacle 4.

A pair of shafts 27, 27 are journaled at their opposite ends in opposing pairs of brackets 22, and four levers, each designated by the reference numeral 28, are fixed to the shafts such that one lever 28 is adjacent each of the brackets. The upper end 29 of each of the levers 28 is urged in an upwardly direction by means of a spring 30 which is mounted on opposed projections 31 and 32 on the lever and receptacle, respectively. The pivotal movement of each lever 28 is limited by an adjustable set screw 33 which passes through the upper arm of the lever 28 and bears against an abutment or stop 34 on the receptacle 4.

The upper ends 29 of the levers 28 are adapted to I cooperate with four dogs 35, 35, etc. on the gate 3 so as to urge the latter in a direction towards the left or right depending upon the direction of movement of the receptacle itself. A plurality of rollers designated by the reference character 36 are journaled for free rotation at opposite sides of the housing 9 so as to support the gate 3 for horizontal sliding movement. 7

As shown inFigure 7, the rail 20 (as would also be the case with rail 21) is provided with two bends 40 and 41 such that the central portion of the rail is elevated relative to the ends thereof. Thus, when the receptacle 4 moves towards the right from the central positionindicated in Figure 7 the right-hand levers 28 are engaging the dogs at the right-hand end of the gate 3 so as to move the gate 3 also towards the right. This relationship will continue until the receptacle 4 reaches the bend 41 in the rail 20, at which point the upperends of the right-hand levers 28 will fall below the lower ends of the corresponding dogs 35 so as to release the gate from further movement with the receptacle. This disengaging position would generally correspond to the relative positions indicated in Figure 3. The receptacle 4 then moves free of the gate 3 toward the right-hand end of the housing 9, after which its direction is reversed. The receptacle moves towards the left until it reaches approximately the position shown in Figure 3, at which time the left-hand levers 28 will contact the corresponding lefthand dogs 35 of the gate 3 so as to commence movement of the latter towards the left. The same releasing and re-engaging action will take place with regard to the bend as has been described with reference to the bend 41.

'means of faulty operation or improper positioning of the gate'following maintenance work, the receptacle 4, on

approaching the gate 3 from either end would be permitted to assume the proper. relationship with respect to the gate 3 since the levers 28 would be depressed by the bevelled "ends of the dogs 35 against the action of the springs 30 The means for reversing the direction of movement of the receptacle 4 after it reaches the extreme rightor left-hand position of travel may be any one of several mechanical, pneumatic or electrical means; however, as shown in Figures 7, 8, and 9, a pair of switches 42 and 43 are located at the leftand right-hand ends, respectively, of the housing 9. As shown in Figure 9, the switch 43 (as would also be the case with respect'to limit switch 42) is provided with an arm 44, the inner end of which is fixed to the operating shaft for the switch and the outer end of which carries a roller 45. The roller 45 is adapted to ride over the upper surface of an elongated cam 46 which is sloped at its ends and which is secured to the receptacle 4 by means of brackets 47. The arrangement of the cam 46 relative to the locations of the limit switches 42 and 43 is such that the receptacle 4 will reverse its direction of movement when it reaches the extreme leftand right-hand ends, respectively, of the housing 9.

The means for driving, or rather pulling, the receptacle 4 in the two opposite directions comprises a pair of cabla 50 and 51 which are attached at their ends to the receptacle 4 by means of a pair of outwardly projecting brackets 52 and 53 having suitable eye-holes therein, as best shown in Figure 8. The other end of cable 50 is wound around a drum 54 which is fixed to the shaft 55. In like manner, the other end of cable 51 is wound around a drum 56 which is fixed to the shaft 57. The drive for the shaft 55 includes a motor 58 and a shaft 59 which is driven by the motor through suitable gear reduction. Power is transferred from the shaft 59 to the shaft 55 by means of sprockets 60 and 61 mounted on these shafts, respectively, and a chain 62 which passes around the sprockets. For the purpose of pulling the receptacle 4 in the opposite direction, power is transmitted from the shaft 55 to the shaft 57 by means of a cable 64 which is wound around two drums 65 and 66 fixed to the shafts 55 and 57, respectively. In the event of power failure to the motor 58, it is possible to disengage the motor by means of a gear shift 67 and to supply power manually through the wheel 68; the details oflthis arrangement are conventional and hence will not be further described.

Figure 12 shows a modification of the present invention wherein a somewhat different mechanism is employed in conjunction with the receptacle for moving the gate back and forth through its open position and into either of its two closed positions. For this purpose. a pair of pivotal levers (only one of which is shown in Figare 12 are employed. Lever 90 is pivotally mounted adjacent its center on a stud shaft 91 projecting out from the receptacle 4 and secured to the side thereof in a suitable manner. The ends of the lever 90 are provided with upwardly projecting portions 92 and 93 which are adapted to engage the opposite ends of the gate'3 and to move the latter in the same direction as the movement of the receptacle 4. In order to pivot the lever 90 out of engagement with the gate 3 so as to limit the movement of the gate, there are provided a pair of cams 94 and 95 attached to the housing internally thereof and positioned so asto teeter the lever from one operating position to the other when the receptacle 4 moves beyond the predetermined ment of the car or by the drive means which moves the f car. Also, the gate might be operated pneumatically, hydraulically or electrically by means of suitable valves and switches in response to the movement of the car or in response to the movement of the drive means which moves the car.

In connection with Figure 6, although but one stoker hopper '6 is showmit should be understoodthat'two or more stoker hoppers mig'ht' be arranged in aline 'suchthat the receptacle4 could feed a plurality of these stokerhoppers. In such a case, adjacent stoker hoppers would "be interconnected with one another by means of aplate similar to plate 10 such that the receptacle 4 would slide over this intervening surface so as not to lose any of its contents when moving between hoppers.

Although the present invention has'been described in particular relation to the drawings included herewith, :it should be understood that other and further modifications, apart from those shown or suggested herein may be made within'the spirit and scope of this invention.

What is cla'imed'is:

-l. A device for receiving a quantity of solid particulate material from at least one essentially point source of supply and for distributing said solid material over at least one 'elongated zone 'of'use comprising a receptacle continuously open at its bottomand top ends,-means supporting said receptacle for movement over said zone of use and into position beneath a point source o'fsupply, a closure means for each point of supply for opening the same and for effecting discharge of solid material into said receptacle when the latter is positioned beneath said point of supply, means for moving said receptacle back and forth over said elongated zone of use and into position beneath at least one of said points of supply, and means responsive to the movement of said receptacle for opening each said closure means as said movable receptacle moves into position beneath the corresponding point of supply.

2. A device for receiving a quantity of solid particulate material from a point source of supply and for distributing said solid material over an elongated zone of use comprising a receptacle continuously open at its bottom and top ends, means supporting said receptacle for movement over said zone of use and into position beneath said point of supply, a closure means for said point of supply for opening the same and for discharging solid material into said receptacle when the latter is positioned beneath said point of supply, means for moving said receptacle back and forth along said elongated zone of use and into position beneath said point of supply, and means responsive to the movement of said receptacle for opening said closure means as said movable receptacle moves into position beneath said point of supply.

'3. A deviceforspreading coal over the upper-rectangular opening of a 'stoker hopper comprising a supply inlet for said coal, a housing connecting with said supply inlet and with the upper rectangular opening of 'said stoker hopper, a receptacle supported within said housing for movement back and forth over said rectangular opening and into position beneath said inlet, said receptacle being continuously open at its upper and lower ends, a

'slidable gate positioned within said housing beneath said inlet for preventing the downward flow of material from said inlet when said receptacle is positioned away from said inlet and for permitting flow of coal from said inlet to said receptacle when said receptacle is positioned beneath said inlet, and means responsive to the movement of said receptacle toward and away from said inlet for opening and closing said gate, respectively.

4. The improvement as set forth in claim 3 wherein said means for moving said gate includes dogs mounted at the ends of said gate and projecting portions at the ends of said receptacle engageable with said dogs as said receptacle is moved toward said inlet.

5.The improvement as set forth in claim 3 wherein said means 'for moving said gate includes an elongated lever pivotally mounted adjacent its center on said movable receptacle, means mounted in said housing and engageable with the ends of said lever for titling the same into one of two diflerent angular positions when said receptacle approaches and moves away from said inlet, andmeans mounted on the opposite ends of'said lever for engaging the ends of said gate and for moving the same as said receptacle moves towards and away from said inlet.

6. The improvement as set-forth in .claim 3 including means mounted adjacent the ends of said housing for reversing the direction of movement of said receptacle.

7. .A device for distributing coal lengthwise over the upper rectangular opening of a stoker hopper comprising a dust-tight housing supported .above said stoker hopper and in open communication therewith, a coal inlet leading downwardly to said housing, a receptacle open at its upper and lowerends movable withinsaid housing along the rectangular opening of said stoker hopper and movable into position below said inlet, a pair of substantially parallel guide rails extending longitudinally through said housing (over .said rectangular opening of said stoker hopper and beneath 'said coal 'inlet, means on said movable receptacle engageable with said rails for guiding'said receptacle over saidrails, means for moving said movable receptacle along said rectangular opening and beneath said coal inlet, a gate mounted insaid housing and positioned beneathsaid coal inlet, said gate being horizontally movable into open and closed positions beneath said coal inlet, dogs mounted on .the opposite ends of said slidable gate, and :projections :on the opposite upper ends of said movable receptacle, said rails having cammed surfaces thereon adjacent the location beneath said coal inlet, whereby, as said "movable receptacle is moved toward said coal islet, said cammed surfaces .will elevate said receptacle such that said projections will engage ;said dogs so .as tomove said gate and open the .same when said receptacle -is positioned directly below said .coal inlet.

8. The improvement ;as set forth in claim 7 including means mounted adjacent the ends of said housing for reversing the direction of movement of said movingmeans and said receptacle.

-9. A device for spreading coal over the upper rectangular opening of a SlOkBl hopper comprising a coal supply inlet horizontally offset vfrom said rectangular opening, a housing connecting with said supply inlet and with the upper rectangular opening of said stoker hopper, a receptaclesupported within saidhousing for movement back ,and forth over 'said rectangular opening .and into position beneath said inlet, saidreceptacle being open at its upper and lower ends, a flat plate extending horizontally from said stokcr hopperadjacent one side edge of .said rectangular opening to a position beneath ,said inlet, thelower'end of saidreceptacle being .slidablezover said-flat plate sons to prevent discharge of coalfrom said receptacle when the same is not positioned over -:said rectangular opening, a slidable gate positioned within said housing beneath said inlet for preventing the downward flow of material from said inlet when said .re- .ceptacle .is positioned away from said inlet and for permitting flow of coal from said inlet to said receptacle when said receptacle is positioned beneath said inlet, means for moving said receptacle from-each end of said housing to the opposite ends thereof, and means responsive to the movement of said receptacle toward and away from said inletfor opening and closing said gate, respectively.

10. The improvement as set forth in claim 9 wherein said means for moving said gate includes dogs mounted at the ends of said gate and projecting portions at the ends of said receptacle engageable with said dogs as said receptacle is moved toward said inlet.

11. The improvement as set forth in claim -9 including means mounted adjacent the ends of said housing for reversing the direction of movement of said moving means and said receptacle.

References Cited in the file .ofthis patent UNITED STATES .PATENI S 1,666,027 Beaumont Apr. 10,1928

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