US2243962A

US2243962A - Stoker

Info

Publication number: US2243962A
Authority: US
Publication date: 1941-06-03
Anticipated expiration: 1958-06-03

Description

June 9. P. A. KETCHPEL 3,

sxoxma Original Filed Aug. 2, 1934 3 Sheets-Sheet 1 IN VEN TOR. PA (/1. A. KETCHPEL s am REDUGEI? ATTORNEY.

June 3, 1941. p A. K H EL 2,243,962

STOKER 1 Original Filed Aug. 2, 1954 3 Sheets-Sheet 2 INVENTOR. PA UL A. K E TCHPEL ATTORNEY,

June 3, 1941.

P. A. KETCHPEL.

STOKER Original Filed Aug. 2, 1934 I5 Sheets-Sheet 3 ATTORNEY.

Patented June 3, 1941 STOKER Paul A. Ketchpel, West Englewood, N. J., assignor' to The Standard Stoker Company, Inc., a. corporation of Delaware Original application August 2, 1934, Serial No. 738,039. Divided and this application January 30, 1936, Serial No. 61,518. Renewed September 29, 1939 21 Claims.

This application is a division of my co-pending application, Serial No. 738,039, filed August 2, 1934, for Stoker.

My invention relates generally to automatic furnaces, and more particularly to small furneces such as are employed in the heating of dwellings, apartment houses and greenhouses.

One object of my invention resides in the provision, in furnaces of the type described, of a novel grate shaking arrangement.

Another object of my invention resides in the novel construction and arrangement of means for removing the ash from furnaces of the type described.

Still another object of my invention resides in the provision in furnaces of the type described, of an improved and novel combination and arrangement of stoking, grate shaking and ash removal means, that is simple in construction, cheap to manufacture, and highly efficient in operation.

' To the above and other ends the invention consists in the arrangement of parts and in their relation and association one with the other or in combination as hereinafter described and as illustrated in the accompanying drawings, in which.

Fig. 1 is a vertical sectionalview of a furnace room showing a furnace and stoker therefor in elevation with parts broken away and with the novel grate shaking arrangement and ash removing device shown applied thereto;

Fig. 2 is a view of the furnace in central vertical section with the stoker, grate shaker and ash removing device applied thereto and shown partly in elevation and partly in section;

Fig. 3 is a sectional plan view through the furnace and bin with the stoker shown in elevation;

Fig. 4 is a vertical central section through the lower portion of the furnace with a modified form of ash conveyor applied thereto and shown in similar section; and Fig. 5 is a sectional view on the line 5-5 of Fig. 4.

Referring now to Figs. 1 to 3, inclusive, of the drawings, which illustrate one embodiment of the invention, a furnace room is designated by the I9 is arranged to permit manual and stoker firing through the firing opening 11.

It will be understood as the description proceeds that the invention is not limited to the particular relation of the bin l4 and the furnace l3 illustrated, since the bin may occupy any one of a number of positions around the furnace and may be nearer to it or farther away. As shown, the bin I4 is at one side of the furnace l3 and a stoker elevating conduit 20 extends upwardly and laterally from a position near the bottom of the bin I4 through the bin wall 2| and terminates a short distance above the firing opening ll of the furnace l3. A screw conveyor 26 is mounted in the elevating conduit 20 and is arranged to be driven from its upper end through the drive shaft 29. cates with the upper end of the elevating conduit 20 and curves downwardly toward the firing opening ll. At its lower end the conduit 40 communicates with a chute 42, that curves down wardly and communicates with the firing opening l1 through the opening 43 in the door 19, discharging fuel into the furnace. The details of construction of the stoker are not described here since they form the basis of my application Serial No. 738,039, of which the present application is a division.

In order to prevent the accumulation of ashes on the grates below the fuel bed, which would hinder the natural draft from passing through the fuel bed, a novel grate shaking arrangement is provided. The lower end of the shaft of the screw conveyor 26 extends into the compartment 39 and is connected with the speed reducer 55 by the universal joint 56. Movement is transmitted from the speed reducer 55 to the drive shaft 51 through the universal joint 58. The drive shaft 51 extends forwardly from the speed reducer through a housing 59, which extends beneath the fioor of the fuel bin, to the furnace l3 and is connected at its forward end to the shaft by a universal connection 6|.

The stoker conveyor screw 26 and the shaft 51 are angularly related both in a vertical plane as shown in Fig. 1 and in a horizontal plane as shown in Fig. 3. In order to reduce the angularity, considered in a vertical plane, at the universal joint 58 between the shaft of the conveyor screw 25 and the shaft of the speed reducer 55, the speed reducer is mounted at an angle to the horizontal, as shown in Fig. 1. To obtain the most favorable angle, considered in a horizontal plane, at the universal joints 56 and 58betwcen the shaft of the conveyor screw 26 and the shaft The conduit 40 communi- !l with the shafts of the speed reducer, the speed reducer is located so that the angle between the shaft 51 and the speed reducer shaft to which it is connected is approximately equal to the angrates an oscillating motion. A handle 68 is pro-' vided for manually shaking the grate I8 independently of the stoker mechanism if it is necessary at any time to fire the furnace manually. To permit of adjustment of the amount that the eccentric 84 rocks the grate I6, 9. link'BS is provided connecting the legs 65 and 65. which has holes III of varied spacing to adjust the lost motion between the eccentric 64 and the legs 65 and 68. The lost motion between the eccentric 64 and the legs 65 and 68 permits the grate to remain stationary for a. period of time at each of the limits of its oscillation. Since the grates remain in rocked position for a space of time, the amount of air drawn up through the grates is increased. This is of particularimportance when the openings between the grates are restricted as in installations adapted for burning of fuel of small size. It is evident that the air supply to the firebox may be increased or decreased by increasing or decreasing the lost motion between the eccentric and the legs 65 and 68.. A protecting shield or plate II may be attached to the legs 85 and 86 to prevent ashes from dropping on the eccentric 64 and from getting in the bearing 82.

The rate at which the grates are oscillated is determined by the rate of speed of the stoker conveyor screw 28, since they are operatively connected therewith through the shafts 60 and 51 and speed reducer 55. Thus, if the stoker is speeded up to produce heavier firing, the grates are oscillated more rapidly to take care of the g eater amount of ash formed. I

A conduit including the trough-like portion I2 and the tubular portion I8 is mounted beneath the grate IE to receive the ashes falling therethrough and extends to the compartment 85. A slope sheet I3 fixed to the rear wall of the furnace in the ash pit 38 beneath the grate I8 and another sheet I secured to the ash door.

I8 provide a self-cleaning arrangement in the by the screw conveyor 11 through the conduit 18 and allowed to drop through the outlets I9 and 80 into the ash containers 8| and 82. tainers are provided with dust proof lids 83 and 84 closely and telescopically fitting the outlets I9 and 80. To keep the ash containers out of sight and provide more floor space, they are disposed in the compartment 85 beneath the furnace room floor, this compartment being covered by the door 85a.

In Figs. 4 and 5 is shown a modified form of The ash con-.

the ash removing device, wherein means is provided for stopping the ash conveyor 86 after the ash receptacles have become filled, allowing the ashes to accumulate in the trough 81 and ash pit 88. The ash conveyor conduit 89 has a hinged door or end cover BI that is pushed open by the accumulation of ashes in the conduit 89 when the ash receptacles are filled. Opening of the door 9| moves a catch 92 and releases the latch 83 mounted on the same shaft as the bell crank 84, which by reason of the weight swings downward moving the rod 90 toward the left.

The rod 96 is connected with the lower end of a clutch yoke 91 which is pivotally mounted at I25 in a bracket 98 attached to the end plate 99. The yoke 91 engages the clutch member I00 which is slidably keyed on the shaft IOI. Normally the clutch member I00 is in engagement with a companion clutch member I02 universally connected with and driven by the shaft I03; however, when the accumulation of ash at the end of the conduit 89 opens the door 8i releasing the latch 83 and causing the bell crank 94 to move the shaft 86 to the left, the clutch members I00 and I02 are disengaged, as shown in Fig. 4, and operation of the ash conveyor screw 80 is stopped.

An alarm may be provided for indicating when the clutch members I00 and I02 have become disengaged and have thereby interrupted the operation of the ash conveyor 80. A clapper H4 is pivotally attached at one end to the clutch member I02, as at I28, and rotates therewith. Looking at Fig. 5, the clutch member I02 rotates in a counterclockwise direction and the clapper II4, during the ascending portion of its movement, because of its pivotal connection I25, rests against the hub portion of the clutch member I02. During the descending portion of its movement the clapper H4 becomes overbalanced and swings downwardly about its pivotal connection I20 striking the bell H5. The bell H5 is mounted on the yoke 81 below the pivotal connection I25 and moves into the path of the clapper II4 when the yoke is moved by the rod 90 in a. direction to shift the clutch member I00 out of engagement with the clutch member I02.

From the foregoing description it will be apparent that the novel combination and arrangement of parts together with the particular structure of various elements permits the maintenance of a shallow level fuel bed that is continuous]? being replenished. The fuel feeding portion of my automatic furnace is arranged to spread fuel over the furnace grate continuously in a thin even stream; the grate shaking portion, since its operation is synchronized with the stoker, shakes the ashes from the fire as rapidly as the fuel is consumed; and, the ash removing portion contmuously conveys the ashes away. As a result, a thin even fire, free from ashes, may be constantly maintained. 1

A shallow fire burns at a much higher temperature and more nearly resembles gas and oil fires, because the natural draft of the chimney can cause the air to pass up through the fire bed and produce a more nearly perfect combustion of the fuel than is possible with a deep fire and a forced draft. Also an increase in the useful heating surface of the furnace is gained over those types of stokers that carry a deep fire bed, since in the latter the fire bed smoulders at a relatively low temperature and usually includes an accumulation of ash. Tests have also shown that the flue gases taken from a furnace having a comparatively thin and hot fire contain a great deal lessxunburned carbon than the flue gases taken from a slow smouldering fire, such as is the condition in deep fire beds.

I claim:

1. In a furnace. room having a floor, a furnace provided with a grate and an ash chamber therebeneath, a trough-like depression in said floor communicating with said ash chamber, a fuel bin, the floor of said fuel bin being on a level with said furnace room floor, a stoker including a conveyor screw arranged to convey fuel from said bin to the furnace, said conveyor screw having an extended shaft projecting beneath the level of said floor, a screw conveyor in said trough-like depression for conveying ash, a housing beneath thefuel bin floor and a drive shaft in said housing operatively connected at one end below the level of said floor with the stoker conveyor screw shaft extension and at its other end with the ash conveyor screw.

2. In a furnace room having a floor, a furnace, a trough-like depression in said fioor beneath the furnace arrangedto receive ash from the furnace, an ash conveyor mounted in said depres sion, a fuel bin, the floor of said fuel bin being on a level with said furnace room fioor, a stoker including a conveyor screw arranged to convey fuel from said bin to the furnace, a compartment beneath the fuel bin fioor, the shaft of said stoker conveyor screw extending into said compartment,

a housing beneath the fuel bin floor communicating at one end with said compartment and at the other end with said trough-like depression, a drive shaft in said housing for said ash conveyor and gearing in saidcompartment operatively connecting said stoker screw conveyor shaft and said drive shaft. r

3. In a furnace, a grate provided with a grate shaker bar, an ash pit beneath said grate, means including a screw conveyor for conveying ashes from said pit, a yoke rigidly secured to said grate shaker bar, said yoke having a pair of leg members extending downwardly, one on each side of the axis of said screw conveyor, an eccentric mounted to rotate with said screw conveyor and arranged to alternately engage said leg members for rocking said grates first' in-one direction and then in the opposite direction.

4. In a furnace, a grate provided with a grate shaker bar, an ash pit beneath said grate, means including a screw conveyor for conveying ashes from said pit, a yoke rigidly secured to said grate shaker bar, said yoke having a pair of leg members extending downwardly, one on each side of the axis of said screw conveyor, an eccentric mounted to rotate with said screw conveyor and arranged to alternately engage said leg members for rocking said grates first in one direction and'then in the opposite direction, said leg members being spaced such a distance apar-tthat the eccentric will intermittently engage said leg members,

5. In a furnace room having a floor, a-furnace and a. fuel bin, a firing opening in said furnace, a stoker fuel conveyor extending upwardly. from the bottom of said bin to the firing opening in said furnace, a compartment beneath the floor of said fuel bin, said fuel conveyor having a shaft extending through the floor of said bin into said compartment, an ash conveyor beneath said furnace, said ash conveyor having a shaft extending into said compartment, a speed reducer in said compartment having a shaft universally connected with said stoker conveyor shaft and a second shaft universally connected with said ash conveyor shaft, said speed reducer being mounted at such an angle that the angle between its first named shaft and the stoker conveyor shaft is approximately equal to the angle between i-ts second named shaft and the ash conveyor shaft.

6. In a furnace, a grate, an ash chamber beneath said grate, a trough arranged to receive the ashes from said chamber, a conveyor in said trough, mechanism associated with said conveyor for shaking said grate, the cross sectional area of said trough at its open mouth being less than the cross sectional area of said chamber, and a plurality of upstanding plates mounted in said chamber forming a restricted opening in the lower portion of said chamber, one of said upstanding plates forming a shield for said grate shaking mechanism from the ash dropping from said grate.

7. In combination with a furnace having a grate, a stoker including a fuel conveyor having a fuel receiving end in communication with a source of fuel supply and a fuel delivery end adjacent the furnace, means for operating said fuel conveyor from its end adjacent the furnace. an ash conveyor beneath said grate for removing ashes from the furnace, means operatively connecting said ash conveyor with the fuel receiving end of said fuel conveyor for operating the ash conveyor from the fuel conveyor, means operatively connected with said ash conveyor for shaking said grate, and means for rendering said grate shaking means and said ash conveyor inoperative independently of said fuel conveyor.

8. In a furnace, a grate provided with a grate shaker ban-an ash pit beneath said grate, means for conveying ashes from said pit, a rotatably mounted eccentric, a common actuator for said ash conveyor and eccentric, and means operatively connected to said grate shaker bar arranged to be engaged by said eccentric for rocking said grates first in one direction and then in the opposite direction.

9. In combination with a furnace having a firing opening and a grate, a stoker fuel conveyor leading from a source of fuel supply to the fir- -ing opening in said furnace, an ash conveyor beneath said grate, said fuel conveyor and said ash conveyor each having shaft extensions terminating adjacent each other, power transmission means operatively connecting the adjacent ends of said shafts, said transmission means having a shaft universally connected with said stoker conveyor shaft and a second shaft universally connected with said ash conveyor shaft, said transmission means being mounted so that the angle between its first named shaft and the stoker conveyor shaft is approximately equal to the angle between its second named shaft and the ash conveyor shaft.

10. In combination with a furnace having a grate, a stoker for conveying fuel from a source of supply to the furnace and delivering it onto said grate, an ash pit beneath said grate, an ash receptacle, means for conveying the ashes from said pit to said ash receptacle, means for operating said stoker, a drive connection between said stokerand said ash conveyorfor operating the latter, means operatively associated with said ash conveyor for shaking said grate, and means for automatically rendering both said ash conveyor and said grate shaking means inoperative when I said receptacle is filled, without interrupting operation of said stoker.

11. In combination with a furnace having a grate, a stoker for conveying fuel from a source of supply to the furnace and delivering it onto said grate, an ash pit beneath said. grate, an ash receptacle, means for conveying the ashes from said pit to said ash receptacle, means for operating said stoker, a drive connection between said stoker and said ash conveyor for operating the latter from said stoker, and means for automatically rendering said ash conveyor inoperative when said receptacle is filled, without interrupting operation of said stoker.

12. In combination with a furnace having a grate, a stoker for conveying fuel from a source of supply to the furnace and delivering it onto said grate, an ash pit beneath said grate, conveying means for removing ashes from said pit,

means for operating said stoker, a drive connection between said stoker and said ash conveyor for operating the latter, said drive connection including a clutch, and means responsive to an accumulation of ash arranged to disengage said clutch for rendering said ash conveyor inoperative without interrupting operation of said stoker.

13. In a furnace, a grate provided with a grate shaker bar, an ash pit beneath said grate, conveying means for removing, ashes from said pit, means securely attached to said grate shaker bar including a pair of depending members, one on each side of said conveying means, an eccentric mounted to rotate with said conveying means and arranged to alternately engage said depending members for rocking said grates first in one di rection and then in the opposite direction.

14. In a furnace, a grate provided with a grate shaker bar, an ash pit beneath said grate, conveying means for removing ashes from said pit, means attached to said grate shaker bar including a pair of depending members, one on. each side of said conveying means, an eccentric mounted to rotate with said conveying means and arranged to alternately engage said depending members for rocking said grates first in one direction and then in the opposite direction, said depending members being mounted for adjustment a desired distance from said eccentric forvarying the rocking movement of said grates.

15. In combination, a furnace having a firing opening in an upright wall thereof, a fuel bin at one side of said furnace, a stoker conduit including a fuel conveyor extending downwardly and laterally with respect to said furnace from said firing opening to the bottom of said fuel bin, an ash conveyor extending laterally with respect to the furnace from the lower portion of the furnace to a point remote therefrom, said fuel conveyor and said ash conveyor each having shaft extensions terminating adjacent each other, means operatively connecting the adjacent ends of said shafts including speed reducing means for operating said ash conveyor at a slower speed than said fuel conveyor, and means operatively connected with the upper end of said fuel conveyor for actuating said fuel conveyor and said ash conveyor.

16. In combination with a furnace having a grate, a stoker fuel conveyor delivering fuel from a source of fuel supply to the furnace, means for operating said stokerconveyor, an ash conveyor beneath said grate for removing ashes from the furnace, means operatively connecting said ash conveyor with said stoker conveyor for operating the ash conveyor from the stoker conveyor, and means for rendering said ash conveyor inoperative independently of said stoker conveyor.

17. In combination with a furnace having a grate, a stoker fuel conveyor delivering fuel from a source of fuel supply to the furnace, means for operating said stoker conveyor, an ash conveyor beneath said grate for removing ashes from the furnace, means operatively connecting said ash conveyor with said stoker conveyor for operating the ash conveyor from the stoker conveyor, means operatively connected 'with said ash conveyor for shaking said grate, and means for rendering said grate shaking-means and said ash,

conveyor inoperative independently of said stoker conveyor.

18. In combination with a furnace having a grate, a stoker fuel conveyor delivering fuel from a source of fuel supply to the furnace, means for operating said stoker conveyor, means for shaking said grate, means operatively connecting said grate shaking means with said stoker conveyor for operating the grate shaking means from the stoker conveyor, and means for rendering said grate shaking means inoperative independently of said stoker conveyor.

19. In a furnace, a grate, an ash compartment beneath said grate, means for conveying ashes from said compartment, a rotatably mounted cam, a common actuator for said ash conveyor and means operatively connected to said grate and engaged by said cam for moving said grate first in one direction and then in the opposite direction. I

20. In a furnace, a grate, an ash compartment beneath said grate, conveying means for removing ashes from said compartment, said grate being provided with a pair of depending members, one on each side of said conveying means, and means operatively associated with said conveying -means arranged to alternately engage said depending members for rocking said grates first in one direction and then in the opposite direction.

21. In a furnace, a grate, an ash compartment beneath said grate, conveying means for removing ashes from said compartment, means securely attached to said grate including a pair of depending members, one on each side of said conveying means, means mounted to rotate with said conveying means arranged to alternately engage said depending members for rocking said grate first in one direction and then in the opposite direction.

PAUL A. KETCHPEL.