US2594974A

US2594974A - Self-clearing star feeder

Info

Publication number: US2594974A
Application number: US8840A
Authority: US
Inventors: Mylting Lauritz Emil
Original assignee: Allen Sherman Hoff Co
Current assignee: Allen Sherman Hoff Co
Priority date: 1948-02-17
Filing date: 1948-02-17
Publication date: 1952-04-29
Anticipated expiration: 1969-04-29

Description

April 29 1952 L.. E. MYLTING 2,594,974

SELF-CLEARING STAR FEEDER Filed Feb. 17, 1948 INVENTOR. AUE/ TZ EM/l NYZ.77N6

.4TTORNEY5- Patented Apr. 29, 1952 SELF- CLEARING STAR FEEDER Lauritz Emil Mylting, Philadelphia, Pa., assignor to The Allen-Sherman-Hoff Company, Philadelphia, Pa., a corporation of Pennsylvania.

Application February 17, 1948, Serial No. 8,840

6 Claims. (Cl. 2LH-36) The present invention relates generally to the art of handling and conveying solids, and is more 'particularly concerned with a novel method for feeding solids and automatically breaking up pieces of material therein which are larger than a predetermined maximum size, and With a novel device implementing that method.

Removal of ashes from hoppers of solid fuel burning furnaces such as industrial steam boilers has been complicated by the presence of clinkers which exceed the maximum size which can be handled by the handling apparatus provided therefor. It is important in such operations to remove the ash expeditiously and without interruption by clinkers or other bodies too large to behandled by the handling means. Such removal should not admit gases into the hopper because the admission of gases decreases the efciency ofthe furnace operation. Open or movable gratings which screen out clinkers which A exceed the maximum permissible size are unsatisfactory because it is necessary to open the housing to permit a workman to break up such clinkers, and at such times air may flow in large volumes into the combustion chamber.

Feeders of the rotary valve type are not satisfactory, for when an oversize clinker enters the rotor, the keys connecting it to the drive shaft are sheared off, thus stopping the ash removing operation until the clinker is removed and the drive keys are replaced.

In accordance with the present invention, not only can satisfactory air or gas sealing be effected, but also oversize clinkers in the ash may be rapidly and automatically broken up without materially aifecting the normal ash removal operation. Disintegration of clinkers is performed by this invention in a novel manner by subjecting the clinker to rapidly repeated impacts. The clinker is subjected to hammer-like blows delivered alternately to opposite sides thereof while it is supported as by an anvil. This rapid, reverse hammering quickly breaks the clinkers to sizes which can be handled with no more than slight delay in the rate of ash removal, and does not result in breakage of the feeder or admission of air to the hopper.

Briefly stated, the method of my present invention thus comprises the steps of removing ashes and clinkers from a combustion chamber, subjecting each oversize clinker to repeated impacts delivered alternately on opposite sides of the clinker and thereby reducing such clinker to pieces smaller than a predetermined maximum size, and moving the ashes and reduced clinkers CJI in use.

to a place Where they may be stored or further treated. In using this method with a modern boiler installation, the operations are preferably continuous, the ashes and clinkers falling into a hopper below the chamber as rapidly as they are produced, and substantially continuously moving the reduced clinkers and ashes to a zone at atmospheric pressure through agas lock so that combustion is not disturbed when the combustion chamber is under a gas pressure different than atmospheric pressure. v

Although the present invention is important in solving the long standing ash handling problem, it is not limited in its use thereto, for it may be used in handling solids composed of any material Where the pieces are of different sizes and some are larger than the handling capacity of the handling apparatus.

One embodiment of this invention is a rotary feeder having a fixed shoe disposed close to the rotor and means for repeatedly reversing the rotor and thereby striking blows on opposite sides of a solid which is in the rotor and is too large to be moved past the shoe.

In the drawings accompanying and forming a part of this specification:

Fig. 1 is a perspective View partly broken away showing one embodiment of the present invention;

Fig. 2 is a horizontal sectional view taken on line 2-2 of Fig. 1;

Fig. 3 is a fragmentary vertical sectional view taken on line 3-3 of Fig. 2; and

Fig. 4 is a wiring diagram showing the motor and motor-reversing connections.

The device illustrated in the accompanying drawings is a feeder which is specifically adapted for removing ash from hoppers of solid fuel burning furnaces. The illustrated device comprises a housing l provided with a flange 2 at the upper side for attachment to a hopper. The housing has an opening 3 at its upper end within flange 2 and through which solids may iiow into the housing, and is open at the bottom for discharge of the solids. A shoe l has a cylindrical portion 5 which nts in opening 3 and a rectangular portion 5 having an undersurface constituting part of a cylindrical surface. This shoe defines a passage for solids from opening 3 onto the valve rotor l. Shoe 4 is preferably adjustable vertically, as by bolts 4a, to main substantial contact with rotor l as the rotor or the shoe or both these parts wear The opposite end walls of housing I are rprovided-with aligned openings to receive-'shaft 3 and with outwardly extending interiorly threaded cylindrical bosses 9 encircling said openings and the shaft 8. Packings Ill engage the shaft 8 within bosses 9 and are pressed against the walls of the housing by glands II which are screwed into the bosses and which, preferably, carry bushings I2 to support shaft 8. Sprocket 2! is keyed to one end of shaft S outside of the'adjacent gland I I. Chain 2| extends around sprocket 20 and around a similar sprocket 22 on the rotor of motor 23. The motor 23 rotates rotor 'i by means of these sprockets and chain.

Valve rotor 'I is keyed to shaft 8 within housing I and its outer cylindrical surface is engageable with the lower cylindrical surface of shoe 4. As is shown, this rotor has a plurality of compartments 26 open at the cylindrical surface of the rotor, these compartments being defined by the opposite end walls 2'I of the rotor, the hub wall 28, radial walls 2Q extending between the end walls 21 and arcuate flanges at the outer ends'of the radial walls.

'It will be understood that when housing I is attached to-the lower portion of a hopper solids may flow from the hopper into the compartments of the rotor which are open to the interior of shoe 4 and that when the rotor is turned the solids within any compartment are emptied out as the open side of the compartment is turned downwardly.

A valve rotor reversing lever or arm 30is rotatably mounted on the outer end of shaft 3. This arm-has a portion 3I extendingtoward motor 23 and lying between the upper and lower throws of chain 2l. At its free end portion 3l carries two chain slides 32 pivotally attached thereto as by bolts 33. The chainslides 32-lightly engage the drive chain 3I when yit-is being driven normally, the upper chain slide lying on the top of the upper throw of the chain and the lower slide lying against the underside of the lower throw of the chain. The other end of arm 30 includes a counterweight'34 and an arm '35 which extends between two

limit compression springs

36 and 31, and at its free end is attached to arm 38 of a dash pot 39. Arm 35, by moving vertically around hub 3B, engages with its free end spring pressed pins 4i] and 4I of microswitches 40a and 4Ia disposed above and below arm 35, respectively. By thus engaging pins '40 and 4I, arm 35 actuates a switch 45 moving it by means of solenoids 46 and 4'I to reverse the direction of rotation of the motor 23 and rotor As shown in Figure 4, the electrical elements in this system include a motor 23 of the conventional three-phase alternating current type, a double-throw, double-pole switch 45, a pair -of

solenoids

46 and 47 for actuating switch 45 and moving it to the right-hand position illustrated or to the opposite position, and a main switch 48 to connect up the wiring of the circuit to the power source.

It will be appreciated by those skilled in the art, however, that other reversible motor systems than the one herein illustrated may be employed. A direct current motor may, for instance, be employed, in which case the same dou ble-throw, double-pole switch system may be used withthe solenoid and microswitches, and the eld of themotor may be reversed to effect reversal of the direction of rotation of rotor 'I to accomplish the obj ects and purposes set forth above.

From the foregoing description it will be understood that so long as the load exerted by motor 23 Ais .less ythan a 4predetermin,ed maximum amount, as when no pieces of solids extend out of a compartment 26 and interfere with rotation of rotor l, the motor will drive chain 2l with a certain amount of slackness in its upper or pulling throw. During this time upper shoe or slide 32 will rest on the chain and arm 35 will be disposed substantially horizontally with its free end disposed approximately midway between pins 4D and 4i Referring to the wiring diagram shown in Figure 4, it may be assumed that the circuit under these circumstances is as shown with a double-throw, double pole switch 45 in the righthand position and switches 43a and 4Ia in the open position. The current is flowing through the circuit with a main switch 48 closed. So long as the rotor operates normally and there is no jamming, the motor will rotate in one direction, and upon jamming the motor will tighten the upper throw of the chain whereby slide 32 will be elevated and arm 35 will move vertically around pivot 30 so that eventually it engages pin 4I. Thus, solenoid 4l is actuated, throwing switch 45 to the left-hand position whereby two phases of three phase motor 23 are reversed and the motor reverses the direction'of its rotation. If the clinker causing the-j am is not thus broken and cleared away so that the motor will continue to rotate with the switch in a lefthand position, the lower throw of the chain will be tightened and lower slide 32 will be moved downwardly and arm 35 moved upwardly, striking pin Solenoid 46 is thereby actuated and switch 45 is moved to the right-hand position as illustrated in the drawing and the rotor is again reversed so that it again rotates `in its original direction. In this manner the rotor of the feeder may berepeatedlyand rapidly reversed in `rotational movement, and this reversing action/will continue so long as any overloading of the motor exists.

When solids in the form of pieces of diierent sizes are being handled, the desire is to rotate the rotor l constantly in one direction, which, for purposes of illustration, here may be assumed-to be counterclockwise as one views Figure 1. -As the rotor is so rotated, solids feed down into-the compartments of the rotor. So long as these pieces are small enough to pass into the compartments, the rotor may be rotated by the exertion of a predetermined amount of pull on the drive chain. However, when pieces too large to pass entirely into a compartment of the rotor are encountered, and, for example, one of these pieces is partly within the rotor and partly within the shoe 4, the rotor will rotate untilit brings the piece of solid against the left-hand side of the shoe 4 with a sharp impact depending in force on the speed of rotation of the rotor. Thereupon the load of the rotor will increase beyond the predetermined amount due to the stoppage of the rotor, the rotor will be reversed and the piece of solid will be struck against the right-hand side of shoe 4, when the rotor will again reverse. In this way the solid will be repeatedly subjected to hammer and anvil-like blows struck alternately on opposite sides of it until it is broken sufficiently for the rotor to rotate freely.

It will be understood from the foregoing description that this invention provides a rotary feeder for solids of various sized pieces which will reciprocate rapidly when pieces too large 'to handle are encountered and will continue to strike such pieces alternately on opposite sides until breakage of the pieces occurs.. En this manner thefeeder automatically clears larger pieces without attention of an operator and with little, if any, delay in the handling of the solids.

Subject matter shown or described but not claimed herein is being claimed in my co-pending application, Ser. No. 4,970, filed January 29, 1948, now Patent Number 2,538,320 of January 19, 1951.

Having thus described the present invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is dei-ined in what is claimed.

What is claimed is:

1. A device for feeding solids comprising a rotary valve including a member through which such solids may flow and a rotor engaging said member and having radial compartments open at the periphery or the rotor to receive solids passing through said member and move them beyond said member, means including a reversible motor for rotating said rotor, means including an electric switch for reversing said motor, and motor load-sensing means for actuating the motor reversing means when the load exceeds a predetermined amount, said load-sensing means comprising a pivoted lever engageable with said switch and means actuated when rotation of said valve is impeded for pivoting said lever.

2. A device for feeding solids comprising a rotary valve including a member through which such solids may ow and a rotor engaging said member and having radial compartments open at the periphery of the rotor to receive solids passing through said member and move them beyond said member, means including a reversible motor and a driven chain for rotating said rotor, means including an electric switch for reversing said motor, and motor load-sensing means for actuating the motor reversing means when the load exceeds a predetermined amount, said reversing means including a lever connecte-d to the rotor rotating means for movement to engage said switch when the motor load exceeds said predetermined amount, said load-sensing means comprising a pivoted lever having vone arm engageable with said switch, and means operatively associated with said chain and the other end of the lever for pivoting the lever.

3. A device for feeding solids comprising a rotary valve including a member through which such solids may ow and a rotor engaging said member and having radical compartments open at the periphery of the rotor to receive solids passing through said member and move them beyond said member, means for rotating said rotor including a reversible motor, a chain and sprockets operatively connected to the motor and rotor and engaged by said chain, means for reversing said motor including an electric switch, motor loadsensing means for actuating the motor reversing means when the load exceeds a predetermined amount, said load-sensing means comprising a slide riding the chain between the sprockets and `'movable relative to the sprockets with fluctuations in the tension of the portion or the chain engaging the slide, and a pivoting lever attached to said slide and engageable with said switch t0 actuate the latter.

4. A device for feeding solids comprising a rotary valve including a member through which such solids may ow and a rotor engaging said member and having radial compartments open at the periphery of the rotor to receive solids passing through said member and move them beyond y said member, means for rotating said rotor in- 6 cluding a reversible motor, a chain and sprockets operatively connected to the motor and rotor .and engaged by said chain, means for reversing said motor, and motor load-sensing means for lactuating the motor reversing means when the load exceeds a predetermined amount, Ysaid reversing means comprising an electric switch operatively connected to the motor and a lever connected to the motor load-sensing means and movable relative to the switch to engage andl actuate said switch and reverse the motor, and said loadsensing means comprising a slide connected to the lever and riding the chain between the sprockets to move the lever and thereby yactuate the switch as the load on the motor varies and the tension in the chain fluctuates.

5. A device for feeding solids comprising a rotary valve including a member through which such solids may flow and a rotor engaging said member and having radial compartments open at the periphery of the rotor to receive solids passing through said member ,and move them beyond said member, means for rotating said rotor including a reversible motor, a chain and sprockets operatively connected to the motor and rotor and engaged by said chain, means for reversing said motor, and motor load-sensing means for actuating the motor reversing means when the load exceeds a predetermined amount, said reversing means comprisingr two electric switches operatively connected to the motor and a lever connected to the load-sensing means and movable to engage and actuate said switches alternately to reverse the motor whenever the motor load exceeds said predetermined amount, and said loadsensing means comprising slides connected to said lever and riding each throw of the chain to move the lever and thereby actuate the switches as the load on the motor fluctuates.

6. Apparatus for handling solids including pieces larger than a predetermined size which comprises a valve rotor having a radial compartment to receive said solids, means for rotating said rotor including a motor, sprockets in the I, motor, and rotor, and a drive chain extending over said sprockets, spaced apart stationary abutments adjacent to the rotor and engageable by pieces which are larger than said predetermined size and which are in said compartment, and means responsive to an increase in load on said rotor rotating means incident to the impacts of the said large pieces of solids against the abutments for reversing the direction of rotation of the rotor upon each such impact, said reversing means including a reversing switch, a pivoted lever engaging said switch and means actuated by said chain for pivoting said lever.

LAURITZ EMIL MYLTING.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 782,213 Barnes Feb. 14, 1905 782,214 Barnes Feb. 14, 1905 954,114 Lappen Apr. 5, 1910 1,121,551 Dobson Dec. 15, 1914 1,143,634 Lane June 22, 1915 1,513,563 Smith Oct. 28, 1924 1,538,450 Stewart May 19, 1925 1,594,562 Riley Aug. '3, 1926 (Other references on following page) Number 7 UNITED STATES PATENTS Name Date Beach Dec. 6, 1927 Taylor et a1 Dec. 6, 1927 Wiebe Apr. 29, 1930 Gibbs Feb. 27, 1934 Newhouse Nov. 26, 1935 Bailey Dec. 17, 1935 Lum Feb. 18, 1941 Auen Nov. 18, 1941 l0 Number Number Name Date Frisch Mar. 14, 1944 Pottjes Sept. 30, 1947 FOREIGN PATENTS Country Date Great Britain of 1901 Germany Jan. 13, 1923 Great Britain Feb. 2, 1933 Germany Sept. 3, 1940 Great Britain Mar. 16, 1944