Gravity discharge apparatus

Abstract

Apparatus and method for conveying granular material by gravity assist from an upper zone and a lower zone by means of a horizontal annular plate which is disposed between the two zones, the plate being orbited in a horizontal plane below a fixed shroud so that the material flows downwardly through the aperture in the plate along a path which moves in a horizontal plane around the periphery of the aperture.

What is claimed is: 
     
       1. Apparatus for conveying granular material by gravity assist from an upper zone containing a mass of the material .Iadd.downwardly through a vertically facing discharge opening in a horizontal wall .Iaddend.into a lower zone at a controlled flow rate comprising: a fixed shroud which is symmetrical about a vertical axis passing through the shroud and having its lower end disposed within the mass of material .Iadd.and directly above the vertically facing discharge opening; .Iaddend.a horizontal annular plate having an aperture therethrough located directly below the lower end of the shroud .Iadd.and above the discharge opening, said annular plate engaging and being supported by said horizontal wall .Iaddend.in a position such that an annularly shaped quantity of granular material formed below the shroud resides on the upper surface of said plate; and means for orbiting said plate .Iadd.relative to said discharge opening .Iaddend.about the vertical axis of the fixed shroud so that granular material is urged inwardly from the annularly shaped quantity of material and over the edge of the aperture in said annular plate along a path which continuously moves around the periphery of the aperture. 
     
     
       2. Apparatus as in claim 1 including means for simultaneously rotating said plate about the axis of said aperture. 
     
     
       3. Apparatus as in claim 1 wherein there are upper and lower horizontal annular plates, each of said plates having an aperture which is registrable with an aperture in the other plate.  .[.4. Apparatus as in claim 1 including a vessel having side walls, said plate forming a bottom wall of the vessel and being in sliding sealing engagement with the lower 
     
     
        edges of said side walls..]. 5. A method for discharging granular material by gravity assist from an upper zone containing an annular mass of the granular material which is disposed below a fixed shroud .Iadd.and above a wall having a vertically facing discharge opening .Iaddend.said method comprising disposing a horizontal annular plate below the shroud .Iadd.and supporting the plate on said wall .Iaddend.in a position such that granular material in the annular mass thereof resides on the upper surface of the plate and orbiting the plate in a horizontal plane .Iadd.relative to said discharge opening .Iaddend.in a manner to urge granular material from the annular mass thereof inwardly to the periphery of the aperture in the plate along a path which moves in a horizontal plane around the 
     
     
        periphery of the aperture. 6. A method as in claim 5 including 
     
     
        simultaneously rotating the plate about the axis of the aperture. 7. Apparatus for discharging granular material by gravity assist from an upper zone containing a mass of the material and feeding the material into a lower zone at a controlled flow rate comprising: .Iadd.a wall having a vertically facing discharge opening through which the upper and lower zones are in communication; .Iaddend.a shroud .Iadd.disposed above the discharge opening and .Iaddend.having its lower end disposed within the mass of material; pouring means disposed below the shroud so as to form a generally annular space therewith, said pouring means .Iadd.being supported on said wall and .Iaddend.including at least one pouring aperture disposed below the shroud .Iadd.and above the discharge opening, .Iaddend.the pouring means, the pouring aperture and the shroud being sized and arranged such that a quantity of granular material with the aid of gravity resides on a peripheral portion of the upper surface of the pouring means within said annular space and such that granular material does not flush by gravity from the mass of material through the annular space into the pouring aperture; and means for traversing the pouring aperture .Iadd. relative to the discharge opening .Iaddend.in a generally horizontal path such that it rolls in a circular path concentric with the shroud and such that at least a portion of the quantity of material residing on the upper surface of the pouring means is first displaced inwardly with respect to the shroud whereupon additional material flows by gravity from the mass into the space formerly occupied by said quantity of material and such that the pouring aperture subsequently moves under the displaced portion to thereby discharge the displaced portion through the 
     
     
        pouring aperture .Iadd.and the discharge opening. .Iaddend. 8. Apparatus for discharging granular material by gravity assist from an upper zone containing a mass of the material and feeding the material into a lower zone at a controlled flow rate comprising: .Iadd.a wall having a vertically facing discharge opening through which the upper and lower zone are in communication; .Iaddend.a shroud .Iadd.disposed above the discharge opening and .Iaddend.having its lower end disposed within the mass of material; pouring means disposed below the shroud so as to form a generally annular space therewith, said pouring means .Iadd.being supported on said wall and .Iaddend.including at least one pouring aperture disposed below the shroud .Iadd.and above the discharge opening, .Iaddend.the pouring means, the pouring aperture and the shroud being sized and arranged such that a quantity of granular material with the aid of gravity resides on a peripheral portion of the upper surface of the pouring means within said annular space and such that granular material does not flush by gravity from the mass of material through the annular space into the pouring aperture; and means for traversing the pouring aperture .Iadd.relative to the discharge opening .Iaddend.in a generally horizontal orbital path about the vertical axis of the shroud, without rotating the aperture itself, such that at least a portion of the quantity of material residing on the upper surface of the pouring means is first displaced inwardly with respect to the shroud whereupon additional material flows by gravity from the mass into the space formerly occupied by said quantity of material and such that the pouring aperture subsequently moves under the disposed portion to thereby discharge the displaced portion through the pouring aperture .Iadd.and the discharge 
     
     
        opening. .Iaddend. 9. Apparatus for discharging granular material by gravity assist from an upper zone containing a mass of the material and feeding the material into a lower zone at a controlled flow rate comprising: .Iadd.a wall having a vertically facing discharge opening through which the upper and lower zones are in communication; .Iaddend.a fixed shroud .Iadd.disposed above the discharge opening and .Iaddend.having its lower end disposed within the mass of material; pouring means disposed below the shroud so as to form a generally annular space therewith, said pouring means .Iadd.being supported on said wall and .Iaddend.including a movable upper plate overlying a movable lower plate, each of said plates having at least one aperture registrable with an aperture in the other plate so as to form a pouring aperture disposed below the shroud .Iadd.and above the discharge opening, .Iaddend.the pouring means, the pouring aperture and the shroud being sized and arranged such that a quantity of granular material with the aid of gravity resides on a peripheral portion of the upper surface of the pouring means within said annular space and such that granular material does not flush by gravity from the mass of material through the annular space into the pouring aperture; and means for transversing the pouring aperture .Iadd.relative to the discharge opening .Iaddend.in a generally horizontal path such that at least a portion of the quantity of material residing on the upper surface of the pouring means is first displaced inwardly with respect to the shroud whereupon additional material flows by gravity from the mass into the space formly occupied by said quantity of material and such that the pouring aperture subsequently moves under the displaced portion to thereby discharge the displaced portion through the pouring aperture. .Iadd. 10. Apparatus for conveying granular material by gravity assist from a mass thereof supported on a horizontal wall provided with a discharge opening, said apparatus comprising: a shroud disposed above the discharge opening with at least the lower end of the shroud being disposed within the mass of material; a plate disposed between said shroud and said discharge opening, said plate being of smaller horizontal dimensions than said bottom wall and having at least one vertically facing aperture in register with the discharge opening; and means for orbiting said plate about a vertical axis in a manner such that the aperture in said plate remains in register with the discharge opening and such that a peripheral portion of the plate will slide under a quantity of material and then carry at least a portion of that quantity inwardly toward said aperture whereby material continuously flows inwardly to said aperture along a path which moves around the periphery of said aperture. .Iaddend..Iadd. 11. Apparatus as in claim 10 including means for simultaneously rotating said plate about the axis of said aperture. .Iaddend..Iadd. 12. Apparatus as in claim 10 wherein there are upper and lower plates each of which has an aperture which is registrable with an aperture in the other plate. .Iaddend. .Iadd. 13. Apparatus as in claim 10 wherein said horizontal wall is the bottom wall of a container having an upright side wall. .Iaddend..Iadd. 14. Apparatus as in claim 10 wherein the lower surface of said plate slidably engages the upper surface of said horizontal wall. .Iaddend..Iadd. 15. Apparatus as in claim 10 wherein the horizontal dimension of said plate is less than the horizontal dimension of said shroud. .Iaddend..Iadd. 16. Apparatus as in claim 10 wherein the horizontal dimension of said plate is greater than the horizontal dimension of said shroud. .Iaddend.