US2792131A - Fuel feeder - Google Patents

Description

May 14,

E. C. MILLER FUEL FEEDER Filed April 25. 1953' 2 Sheets$heet l INVENTOR 14m E C. M/LL ER ATTORNEY y 14, 1957 E. c. MILLER 2,792,131

FUEL FEEDER Filed April 25, 1953 2 Sheets-Sheet 2 33 as 3a 71 n n n n n n "J 4 u u u u u q 32 ll [l H II D B LI U U U Ll 3/ 32 INVENTOR Emma CM/LLER ATTORNEY United States Patent FUEL FEEDER Earle C. Miller, Worcester, Mass., assignor to Riley Stoker (iiarporation, Worcester, Mass., a corporation of Massac usetts Application April 23, 1953, Serial No. 350,745 2 Claims. (Cl. 214-18) This invention relates to a fuel feeder and more particularly to apparatus for the feeding of waste materials such as bagasse to a spreader stoker for use as a fuel in a furnace.

It is economical and convenient to burn the lay-products of certain processes in the furnace of a steam generating unit and to use the resulting steam in the operation of one of the processes. In this way fuel for the process steam is provided and, at the same time, a ready method of disposing of the waste by-product material is provided. An example of this is the sugar industry where bagasse, the residue of the sugar cane after the sugar juices have been removed, can be burned in the furnace of a steam generating unit to provide steam which may be used to evaporate the sugar juices. Another instance of such operation is the lumber industry, where the bark and branches may be cut up into relatively small pieces and burned in the furnace of a steam generating unit to provide steam for driving steam engines for cutting lumber. In the past, these waste materials have been fed down an inclined chute to the furnace in which they are to be burned; in

the case of bagasse, particularly, the material has been thrown into the furnace to form a large pile which burns to provide the necessary heat for steam generation. However, in order to assure that the, fuel burn properly, various modern methods of burning fuel have been used with these materials. Improved dumping grates and traveling grates have resulted in convenient disposal of the ash after the fuel has burned and such stoking means as rotary spreader stokers and pneumatic spreader stokers have provided for even distribution of the fuel over the grate surface. However, these improved fuel burning means have been hindered in their operation by the fact that the feed of fuel has been erratic. Even when feeder means of the well-known types have been used in the chute preceding the spreader, difiiculties have been experienced from clogging. Such clogging results in the feeder passing fuel downwardly to the spreader either erratically or not at all. Many of the ditficulties experienced in these prior .art devices have been obviated in the present invention in a novel manner.

It is therefore an outstanding object of the present invention to provide a means of introducing waste materials into a furnace in an efficient, evenly-flowing manner.

Another object of the present invention is the provision of means for feeding bagasse and the like to a spreader stoker in an even manner.

It is another object of the invention to provide a waste material feeder which will not clog.

A still further object of the present invention is the provision of an endless belt feeder for bagasse having means associated therewith for preventing clogging.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a 2 few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Figure 1 is a schematic view of the invention showing a feeder in association with a fuel spreader,

Figure 2 is a sectional view of the feeder of the invention taken on the line 2-2 of Figure 3, and

Figure 3 is a sectional view of the invention taken on a line 3-3 of Figure 2. 7 Referring first to Figure 1, the feeder of the invention designated generally by the reference character 10 is shown mounted on a furnace wall 11 in association with a pneumatic spreader stoker 12. The feeder 10 is mounted somewhat upwardly and forwardly of the pneumatic spreader stoker 12 and an inclined chute 13 extends between the two. A stoker opening 14 is formed in the furnace wall to pe'rmit the introduction of the fuel into the furnace. The pneumatic spreader stoker 12 is providetl with an air inlet duct 15 having an adjustable vane type valve 16 for controlling the air flow into the spreader stoker. A main body portion '17 of the stoker is provided at the rearward end with a nozzle 18. A fuel distributing plate 19 is mounted inwardly of the nozzle 18 within the opening 14 of the furnace wall. This fuel distributing plate is adjustable about a horizontal axis by the actuation of a handle 20 external of the furnace. The lower portion of the chute 13 is situated just above the fuel distributing plate 19 and the upper end is somewhat flared at 21 where it connects with the housing 22 of the feeder 10.

Referring now to Figure 2, the housing 22 of the feeder 10 is connected to the lower end of a chute 23, the upper end of which is connected to a large storage hopper or the like, not shown. The chute 23 is inclined at an angle of about 60 degrees to the horizontal and enters the housing 22 of the feeder at that angle. Situated in the lower part of the housing 22 is an endless belt 24 having an upper running surface which moves toward the furnace and carries bagasse which has fallen onto it from the chute 23 to a forward position where it falls downwardly through an opening 25' in the housing 22 and into the chute 13. The rearward end of the endless belt 24 moves around a series of idler wheels 26 which are mounted on shaft 27. At the forward end, the belt moves around wheels 28 which are mounted on a driven shaft 29. A horizontal guide plate 30 extends between the upper portions of the wheels 26 and 28 to form a horizontal surface over which the upper run of the belt may pass. The belt itself is actually made up of a series of link belts 31 having at relatively frequent intervals upstanding dogs 32.

Mounted above the endless belt 24 at a position somewhat forwardly of the shaft 29 is a shaft 33 upon which is mounted a cylindrical levelling drum 34. This drum is provided with pegs 35 which are somewhat elongated in the circumferential direction and which are spaced fairly closely together over the entire surface of the levelling drum 34. Mounted upon the upper portion of the housing 22 is a gear reduction unit 36 upon which in turn is mounted an electric motor 37. The gear reduction unit 56 and the motor 37 are mounted on the housing by means of an adjustable support 38 by which means their position may be shifted Within certain limits. The output shaft of the gear reduction unit 36, the driven shaft 29, and the shaft 33, are each provided with pulleys around which is passed a belt. The belt passes over the pulley 41 of the gear reduction unit 36 and the pulley 39 of the driven shaft 29 in the usual manner so that the endless belt 24 is driven. The intermediate portion of the belt contacts the pulley 40 on the shaft 33 in order that the levelling drum 34 may be driven also. The relative sizes of the pulleys 39 and 40 are such,

however, that the peripheral speed of the levelling drum 34 is approximately twice the linear speed of the endless belt 24.

The operation of the apparatus of the invention will now be understood in view of the above description. The bagasse comes down the chute 23 from a hopper and falls onto the rearwardly moving upper surface of the endless belt 24. The bagasse will be in the form of long resilient strips and will include a certain amount of smaller material. The bagasse will be moved rearwardly toward the rearward end of the endless belt with the dogs 32 providing traction. The bagasse in the lower part of the chute 23 will tend to be more or less matted and the dogs 32 will steadily tear successive layers of the material away from the main mass. However, there is a tendency for the bagasse to fall on the endless belt in large tangled masses. It would be obviously undesirable spreader since not only would the feed rate be irregular but the matted mass would be too large for the spreader to handle. Therefore, when one of these large masses of bagasse is carried rearwardly on the endless belt, its upper portion contacts the levelling drum 34. The high peripheral speed of the levelling drum and the tearing, rendering action of the teeth 35 immediately reduces the mass to a blanket having a thickness equal to the vertical distance between the upper portion of the dogs 32 and the lowest extent of the teeth 35 on the levelling drum.

Furthermore, the excess bagasse over and above this blanket thickness is thrown forwardly in the housing 22 and falls downwardly through the opening 25 into the to permit these masses to fall down the chute 13 to the I therefore particularly point out and distinctly claim as my invention:

1. A fuel feeder for regulating the flow of bagasse and the like to a spreader stoker comprising an endless belt having an upper horizontal surface, an entrance chute having its lower end above the said surface for introducing the bagasse thereon, a discharge chute extending downwardly from the discharge end of the belt, there being projecting dogs extending upwardly from the said surface, a toothed drum mounted on a fixed horizontal axis above and spaced inwardly from the dis charge end of the endless belt transversely thereof, a motor driving the belt and the drum, and a connection between the motor and the drum and belt such that the peripheral speed of the drum is considerably greater than the surface speed of the belt.

2. A fuel feeder for regulating the flow of bagasse and the like to a spreader Stoker comprising an endless belt having an upper horizontal surface, an entrance chute having its lower end above the said surface for introducing the bagasse thereon, a discharge chute extending downwardly from the discharge end of the belt, there being projecting dogs extending upwardly from the said surface, a cylindrical drum mounted on a fixed horizontal axis above and slightly inwardly of the discharge end of the endless belt transversely thereof, the said drum having a plurality of pegs extending radially therefrom, a motor driving the belt and the drum, and a connection between the motor and the drum and belt such that the peripheral speed of the drum is approximately twice the surface speed of the belt, the entrance chute being inclined so that the bagasse as it falls on the moving surface of the belt has a horizontal component of motion in the same direction as the said surface.

References Cited in the file of this patent UNITED STATES PATENTS 741,472 Farquhar et al Oct. 13, 1903 812,635 Caldwell Feb. 13, 1906 943,712 Snyder et a1 Dec. 21, 1909 2,489,594 Sherman Nov. 29, 1949 2,624,447 Small Jan. 6, 1953

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