US 2115464 A
Description (OCR text may contain errors)
April 26, 1938. C, C, K|RBY A 2,115,464
' sToKER FiledAug. 15, 1934 's sheets-sheet 1f APHl 25, 1938- I c. c. KIRBY 2,115,464
y i STOKER i Filved Aug. 15., 1934 3 Sheets-Sheet 2 C. C. KIRBY,
April 26, 1938.
STOKERv Filed Aug'. 15, 1934- 5 Sheets-Sheet 3 Patented Apr. 26, 1938 UN11ED STATES PATErVr- OFFICE s'roxEa ohm-les c. Kirby, Decatm n1. Appncmn August 15, 1934, serial No. '139,848
3 claims. (o1. 11o-115) and measured output of fuel which is fed into the fire bed of the furnace.
Another important object of the invention is the provision of a novel, simple and highly eilicient means vfor distributing the fuel in an even and uniform layer over the;k entire flre box area, thus accomplishing more complete and emcient combustion of the fuel in the furnace.
A further important object of the invention is the provision of a stoker which is built into a completeportable unit, and'which may be cheaply manufactured to perform its operations in a positive and effective manner.
A further important object of the invention is the provision in a Stoker of mechanism for manually varying the amount of fuel delivered'by the stoker into the furnace in an amount proportionate to the size of the fire box in the furnace;
A still further object of the invention is the provision of means for automatically restraining the delivery of fuel after a predetermined amount has been fed into the re box,'4 and for automatically releasing said means to start a new delivery of fuel.
Another object of the invention is the provision of means whereby the fuel delivered into the re box of the furnace will be maintained below a predetermined size.
Numerous other objects and advantagftscf'the:
Figure 1 is a side view of the stoker embodying my present invention connected to a furnace and showing the hopper, screw conveyer, and distribution chamber in section; l
Fig. 2 is a horizontal section taken substantially on'the line 2-2 of Fig. 1;
Fig. 3 is a fragmentary enlarged sectional view of a portion of the hopper and screw conveyer and shows the adjustable feed control mechanism;
Fig. 4 is a section taken substantially on the line 4 4 of Fig. 3;
Fig. 5 is a fragmentary .view showing a portion of the feed controlmechanism in a different position from that shown in Fig. 3;
Fig. 6 is a perspective View of the distribution chamber;
Fig. 7 is a perspective view of the distribution disk;
end a lid or closure II, front and side walls I2 la notch or aperture 22 to provide an exit for the 126, is adapted to rotate within the conveyer tube I 8 and extends to practically the full length there- Fig. 8 is a perspective view showing the screw conveyer insert for preventing oversize lumps of fuel from entering the conveyer screw;
Fig. 9 is a plan view of a modified form of distribution disk; and 5 Fig. 10 is a wiring diagram of the circuit for automatically operating the Stoker.
Referring to the drawings, the stoker is shown comprising a storage hopper I Il having at its upper 10 sloping inwardly from top to bottom to form a trough-shaped portion I3 at its lowest extremitlr and a. vertically disposed rear wall.
The trough portion I3 may be welded or otherwise secured by an angle band I4 to effect a sealed 15 closure with a member I5 of tubular form having teeth I6 along the upper edge and along one of the vertical edges of an aperture I1, the teeth I6 serving to break up any unduly large lumps of fuel which may have entered the hopper. 20
The member I5 is adapted to embrace a vertically disposed screw conveyer tube I8, which is provided at its lower end with a notch or aperture I9 corresponding in height to the trough I3 and is cut back in depth to its axis as shown at 25 20, to allow for the entrance of the fuel. Adjacent and below the aperture I 3 the tube I8 is rigidly mounted in any desiredmanner on the frame or housing of a gear reducer 2|.
The conveyer tube I8 has at its uppermost end fuel into av distribution chamber housing, generally designated by reference character`23.
3A screw conveyer 25, fixed to a driven shaft of, i. e. from the base of the trough I3 to theV lower end of the` upper aperture 22. Adjacent the lower portion of this screw 25 is a cup-shaped closure member 2l which is adapted to snugly embrace the inner wall of the tube I8 and the shaft 26, thus preventing any escape of dust or foreign matter into the mechanism directly below, as will be later described.
The screw 25 has at its upper end a paddleshaped member 28 in registration with the notch 22 and adapted to be xedly held on the conveyer shaft 26 so that the screw and paddle. will rotate in unison. l A
Referring'now to Fig. 1, the gear reducer 2l is fastened rigidly by means 3| to a rectangularshaped base or support member 32 having casters 33 which may either be xedly or swivelly mounted, the base member also serving to support the storage hopper through supports 34.
Referring now` to the main drive mechanism, I
have provided a motor 35 vertically disposed and spaced apart from the conveyer tube I8 having bearing at its'- lower end at 36 on the frame of side portions 4| and a horizontal base portion 42 which is formed with a fiange portion 43 to enclose the tube I8. The distribution chamber terminates in an opening 44 which is adapted to -abut a door 45 of a furnace 46, this door having an opening 41 of width and length to match the opening 44. To preclude leakage of dust, etc., during the operation ofthe stoker, an angle iron strip or other suitable means 41' is or may be weldedl around the periphery of the opening 44- to abut against the door 45.
It will be noted that :the outwardly flaring sides 4| of the distribution chamber (Fig. 1) have a top horizontal edge 48, and downwardly sloping edges 49, continuing into a horizontal edge 50 which terminates at the furnace door 45. A cover plate 5|, whose surface conforms to and rests upon the edges of the distribution chamber,
serves asan enclosure for this chamber. A removable plate 52, held in place by means 53 above the opening 44, is provided for the purpose of observing the condition of the fire box from time to time as desired.
Referring now to the portion of the conveyer tube immediately below the aperture 22, an inclined guide chute 55 is formed and fastened to the tube at 56. 'I'he chute extends downwardly to within a normal working distance of the dis' tributor disk 39 and in its extension may preferably be, arcuate in form. A deflector bar 58 is pivoted at 59 to the lower end of the guide chute 55.
The distributor disk 39 comprises a rotating` circular disk 6| having a plurality of blades 62 fastened to its upper 'surface by bolts 63, or other suitable fasteningA means. The blades 62 may be of angle iron form and, as will be seen from Figs. 2, 7, and 9, are placed with their outermost ends 64 diametrically opposite one another and in close-proximity to the periphery of the rotating disk. These blades extend along the surface of the disk with their vertical planes lying on either side of its axis and equidlstant therefrom. The' blades are parallel to. one another and terminate at 65 just before reaching the center of the disk. Slots 66 are or may be provided for angular adjustment of the blades if desired (see Fig. 9)..
'I'he distributor disk is rigidly secured to the upper extension of the motor drive shaft 31 by suitable means 61. Referring to Fig. 1 it will be apparent that the distributor disk assembly is positioned in close proximity to the base of the distribution chamber housing 23, which obviates the danger of pieces of fuel or foreign matter vlodging beneath the distributor disk. A housing 68 is provided for protection from the rotat- "means, a brief explanation of the operation of the parts thus far described may serve to more clearly disclose .the invention. Assuming that the circuit for 'the motor is closed, rotation of the motor shaft which normally runs at 1750 R. P. M.-
will, through the gear reducer, rotate the conas the invention is later described. Fuel will be fed up the screw and to the paddle-like structure which tends to prevent any crowding of the fuel, the fuel then dropping by its own weight down the inclined chute and onto the rotating distributor disk. The staggered blades on the disk tend to hurl the pieces of fuel through the opening in the fuel door of the furnace'and into the lire box chamber. This operation continues until automatically stopped'.
The mechanism for accomplishing this automatic stopping (Figs. 3 to 5)"comprises a ratchet wheel 15, pinned at 16 to a horizontally disposed. shaft 11 having bearing at 18 in a support o-r bracket 19 which in turn is rigidly secured at to the gear reducer housing 2|.
Fastened to the support 19 atl 8|-and vertically disposed relative thereto is a second support 82 having a horizontal bearing 83 adapted to receive an adjustable tubular sleeve 84, the inner or rearward end of which extends through an opening in the conveyer tube below the cuplforward end and being secured at its rearward end to the rod 81 in any desired manner.
The reciprocating rod 81 has a correspondingly reduced portion 89 which extends from the shoulder 88 beyond the end of the tubular sleeve to abut against an eccentric 9| which'may be pinned or otherwise fastened to the screw conveyer shaft at 92. 'Ihis rod extends beyond the spring housing member and is provided with a flattened portion having a pivot 93 for a connector link 94 in turn loosely pivoted 'at 95 to a lever or arm 96. The lever or arm is loosely' mounted on the shaft 11 and is provided with a ratchet dog or pawl 91 adapted to drive the ratchet wheel in a counter clockwise direction, viewing Figs. 3 and 5.
Also mounted on the ratchet wheel shaft 11 opposite thel ratchet wheel and adjacent the bracket 19 is an arm 98 rigidly fixed to the shaft 11 at 99 and pivoted at |00 to a connecting link IUI. The link I0| is `pivoted toan arm |02, fixed to a stub shaft |03 adapted to operate a switch |2|, to be described hereafter, within a housing |04.
Referring to the support 82, it will be noted that an extension |05 is provided, extending above and forming a part of the horizontal bearing 83 in the support. 'Ihis extension |05 is provided with an opening |06 adapted to receive a plunger |01 having a knurled head |08 at its upper end and a conical-shaped member |09 at its inner end. The conical member |09 is normally urged into any one of a series of corresponding conical openings ||0 by a spring I within an enlargement of the opening |06. The openings ||0 are located in the upper surface of the adjustable tubular sleeve 84, and a key and keyway (not shown) prevents the tubular sleeve from rotation about its axis and consequent misalinement of the openings ||0 .with the plunger.
- away from the shoulder v88 in the sleeve 84.
Motion is thus imparted to the arm 95 which, through its pawl 91, rotates the-ratchet wheel 15 through a portion of its circumference, after which the spring 85 urges the mechanism to its original position as shown in Fig. 3. The motion of the ratchet wheel, which is fixed to the shaft, imparts a corresponding degree of motion to the linkage and to the switch. A complete revolution of the ratchet wheel serves to oscillate the switch operating shaft from an open to a closed position and back to open position. To prevent any but a uni-directional motion of the ratchet wheel a gravity held latching dog HZ is provided, which is pivoted at ||3 in the ratchet shaft support 19. It will be apparent that the longest possible stroke vof the rod 31 and pawl 91, which would correspond tothe complete throw of the eccentric 9|, will impart a complete revolution to the ratchet wheel 15 in the shortest possible time, and this may be interpreted as the minimum time for deing, it being understood that any number of adjustments may be incorporated without changing any ofv the desirable features.
The mechanism just described is illustrated in Fig. 5 and it will be apparent that in the new adjustment therein shown the entire ratchet driving assembly will be drawn forwardly or outwardlyv leaving a gap between the end of the reduced portion 89 and the engaging surface of the eccentric 9|. In. this manner the distance travelled by the ratchet wheel for each revolution of the eccentric will be lessened, necessitating a larger number of revolutions for the screw conveyer shaft to complete one revolution of the ratchet.
wheel, which constitutes a complete cycle of operation. Moving the plunger into still another notch will again vary the time of a complete cycle.
It will be apparent that this mechanism may be operatedeffectively by an unskilled operator and that it provides for a series of adjustments into the distribution chamber where it falls normally by its own weight onto the rapidly whirling distributor disk, the blades on the distributor disk carry the fuel with it and the centrifugal forces tend to throw the fuel away from the whirling disk and into the furnace As the fuel leaves the guide chute it will contact or strike the blades at,
different points along their presented faces thus varying their angular directions on leaving the The fuel is thus directed into the furnace .ina plurality of varying` angular directions until YeIyfPOrtion of the area of the fire box is covered i ith a; uniform and evenly distributed layer.
u' l,Spreading a layergf fuel on a fire bed in this manner causes a morey even and intense distribution of heat within the combustion chamber and enables steam to be generated in a much shorter time than is required in the methodsI now employed where the fuel is either heaped or banked in the fuel box. y
Exhaustive tests have shown that preparing the rebox in the manner hereinbefore described has resulted in greater efficiency in the operation of the furnace with a much i'lner ash deposit and less clinkers than has heretofore been possible. It has also been found that placing the motor in the position illustrated on the drawings has served to keep it cool, a factor which is most important in the upkeep of the machine.
The invention is also intended for automatic operation and to this end Fig. 10 discloses a wiring diagram in which leads ||1 and 8 maybe connected to any'electric outlet to operate the motor 35. A switch |2|, connected in parallel with other switches in the circuit, is the switch referred to above as being within the housing |04 and oscillated by the linkage of the ratchet wheel mechanism previously described and closes the circuit through contact with the segment |22.l
When the ratchet wheel mechanism has completed its cycle of operation the -switch is thrown into an open circuit position, as shown in broken lines in this figure. A thermostatic switch |23, connectedin series with the motor 35 and in parallel with the switch |2|, may be used to close the circuit to the motor when the temperature at any desired control point in the heating system falls below a predetermined point. When this takes place the stoker will operate through another complete cycle and be stopped, unless the thermostatic switch is still closed, which will automatically initiate another complete cycle of operation. These two switches will automatically control the operation of the stoker without any attention except for the replenishing of fuel to the hopper.
A third and manually operated switch |25 may be employed to initially start the device into operation, and this switch is held in a normally inoperative position by a spring |26. 'Ihis switch |25 may be mounted on-or within the housing' |04 for convenience, if desired, as showngin Fig. 3. In its initial operation, the switch |25 is urged into a closed circuit position, the operator holding the switch in this position momentarily until vthe switch |2| acts to close the circuit to the motor, after which the switch |25 is released., It is apparent that a full automatic switching arrangement might be provided, the form shown on the drawings being merely a preferred arrangement and forms no part of the present invention.
It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent4 .ber, a hopper, extending to a point below the charging chamber, a screw conveyor arranged to convey fuel upward from said hopper to said charging chamber, means inthe charging chamber directing the fuel to the impeller, a motor below said impeller, a shaft substantially parallel to said conveyor extending vertically from said motor and operatively engaging said impellerl operatively engaging said impeller and said motor, and means operatively connecting said motor and said conveyor, said means being so constructed and arranged as to x the relative speeds of said conveyor and said impeller at a predetermined ratio.
3. In a furnace stoklng mechanism a charging chamber having a discharge outlet adapted to communicate with a furnace, a rotary impeller in said chamber, a hopper extending to a point below *the charging chamber, a screw conveyor arranged to convey fuel upward from said hopper to said charging chamber, means in the charging chamber directing the fuel to the impeller, a
motor below said impeller, a-shaft substantially parallel to said screw conveyor extending upward from said motor and operatively engaging said impeller and motor, and means operatively connecting said motor and said conveyor.
CHARLES C. KIRBY.