GB2120215A - Vibratory apparatus for de-piling a mass of particulate material - Google Patents

Abstract

A vibratory apparatus for de-piling a mass of particulate material comprises a vibrated trough 16,17 surmounted by an upwardly-convex deflector 22 and arranged between an opening in a pile-supporting surface and an endless conveyor 33, a central opening 18 in the trough allowing material to pass on to the conveyor when the trough is vibrated, and vertical gates 60 being provided to prevent flow when the trough is still. <IMAGE>

Description

SPECIFICATION Vibratory apparatus Background of the invention De-pilers, or unpiling apparatus, have been used for quite some time. The normal application is in conjunction with a power station or other coal burning facility wherein large piles of coal are dumped over openings in the ground which lead into tunnels communicating with the furnace or other place of ultimate use. In such installations, a cylindrical hopper is located in the opening beneath the pile and the hopper can be vibrated in order to deliver material from the pile into the feeder. The feeder feeds the material delivered thereto ar a regulated rate, the outlet of the feeder being connected to a conveyor such as a belt or the like which carries the coal at a predetermined rate to a furnace or other place of use.While feeders in the system just described normaily operate constantly, the hoppers are operated at spaced intervals with periods of rest therebetween. This is normally because the delivery rate of the hoppers far exceeds the requirement of the feeders, and if the hoppers were vibrated with material therein which was not being discharged, the material would tend to pack and eventually bridge, causing cessation of flow.

The apparatus disclosed in my U.S. Patent No.4,131,193 issued December 1978, has eliminated the hopper structure and has been very successful in unpiling particulate material. The structure patented in the '193 patent includes adjustable extension members on a deflector for regulating flow of the material by controlling the static angle of repose of the material when the vibratory apparatus is not operating.

Summary of the invention According to the present invention, an improved structure is provided for regulating the delivery of material. The structure is such that upon starting the vibratory apparatus the material will again readily start to flow and continue to flow at a desired rate. The structure is such that no large head of material builds up against the structure causing start up problems due to compacting of the particulate material behind the structure. The structure is located in a way that it can be adjusted to vary its setting without removing all of the material stacked up on the apparatus. Preferably, the vibratory apparatus is arranged so that its rate of feed or delivery of the material can be varied. The arrangement is such that when the feeder is stopped, delivery of material also ceases; when the feeder is again started, delivery will resume.Also, if desired, the feeder may be operated continuously over relatively long periods. The result is that any tendency of the material to bridge or clot is avoided, the rate of delivery from the pile to the conveyor can be regulated, and a more efficient delivery of particulate material to the ultimate place of use can be achieved.

Brief description of the drawings Figure 1 is a perspective view of the vibratory apparatus portion of the present invention; Figure2 is a vertical section along line 2-2 of Figure 1; Figure 3 is an enlarged broken away view of a portion of the gate forming a part of the apparatus in Figure 2; Figure 4 is a vertical section like Figure 2 showing the apparatus at rest but with material piled thereover; and Figure 5 is a view like Figure 4 with the apparatus in operation.

Description of the preferred embodiment Referring now to the embodiment of the invention shown in Figures 1 and 2, there is provided a vibratory apparatus 10 to be mounted just below a large opening or aperture 11 in a base 12. Actually, the base is formed by a concrete top 13 forming a portion of a tunnel or passage 14 beneath the opening. Under normal circumstances, the top of the base 12 will be at ground level and the aperture 11 is located immediately below a dumping place for the particulate material to be handled. In the normal installation, the material is coal, reduced to relatively small size, and an elevated railroad track is located over the aperture 11 so that the railroad cars carrying coal can be emptied with their contents falling downwardly and forming a pile on the base overlying the aperture 11.Located within the aperture 11 is the vibratory apparatus which includes a rectangular (preferably square) trough 15 having side walls 16 and 17 sloping downwardly to a center opening 18 which extends the entire length of the trough. The trough has end walls 19 and 20 and a center wall 21 which are vertically arranged as shown.

Overlying the opening 18 in the trough is a deflector generally designated 22 which has a first portion 22a arching downwardly from the center of the deflector toward the side wall 17 of the trough, and a second portion 22b arching downwardly from the center toward the side wall 16. The highest portion of the deflector 22 is spaced above the center of the opening 18.

The trough 15 is secured to beams 25 and 26 extending along the sides thereof with the beams being supported on isolation springs 27 carried by posts 28 supported on the floor 29 of the tunnel 14.

A vibration generator 30 is secured by means of springs 30a and 30b to the beam 26 in order to impart vibrations to the trough 15. Preferably, the vibration generating apparatus 30 is similar to that shown in my U.S. Patent No. 3,358,815, so that the amplitude of the vibrations generated thereby may be varied in order to vary the rate of discharge of the particulate material.

Material discharged from the trough 15 through the opening 18 falls upon a conveyor belt 33 moving on idlers 34 through the tunnel 14. The return of the belt is indicated at 35.

Dust seals 36 and 37 extend between a pair of vertical plates 31 forming the edges of the aperture 11, and the top of the beams 25 and 26. A second pair of dust seals 38 and 39 extend between the bottom of the trough 15 and the edges of the conveyor.

When the material is piled on the trough 15, it ultimately forms a large pile over the base 12 completely covering the opening 11. The material tends to pile up and stop between the outer edges of the extension members and the tops of the adjacent side walls 16 and 17 of the trough. In this condition, with the trough at rest, no material is delivered through the opening 18 onto the conveyor 33.

The angle of repose, sometimes called the slump angle, of a particulate material depends upon the nature of the particulate material involved. Some materials may be piled higher (large angle of repose) than other material. When the piling continues after the pile of material has reached its angle of repose, the material will slump, increasing the diameter of the base of the pile while maintaining the angle of repose constant.

Vibrating a pile of material dramatically reduces the angle of repose. The apparatus and mode of operation thereof as described hereinabove is substantially as shown and described in my issued U.S. Patent No.

4,131,193, which patent is incorporated herein by reference.

In the patented apparatus, it has been found advantageous for handling certain particulate material to have as narrow a deflector 22 as is possible so as to open up the flow path around the side edges 24a and 24b of the first portion 22a and second portion 22b, respectively, of the deflector 22. However, in opening up the flow path around the edges of the deflector 22, the material could continue to flow from the pile to the conveyor 33 even with the vibration generating apparatus 30 shut off. That is, the angle of repose of the material is such that the inner edges of the line forming the angle of repose with the horizontal overlaps the center opening 18 such that some material can continue to flow to the conveyor 33 even with the apparatus shut off.To control the flow of material when the vibration generating apparatus 30 is shut off, adjustable gates 50 are secured to the edges of the center opening 18 which gates 50 will intersect the angle of repose of the particulate material arresting further free flow of the material. Specifically, a pair of downturned flanges 51, in the form of angle members 52 which are welded to the underside of the side walls 16 and 17 of the trough 15, define the elongate side edges of the rectangular center opening 18. A plurality of longitudinally spaced apart and parallel elongate slots 54 are formed through the downturned flanges 51. Each gate 50 is secured to one flange 51 by a plurality of transversely projecting threaded studs 56 secured to said gate and extending through the slots 54 in the flange 51.Nuts 58, threaded on the studs 54 and tightened, will lock the gates 50 in place on the trough 15. The upper edge 60 of each gate 50 can be vertically adjusted to a desired position above the walls 16 and 17 of the trough by loosening the nuts 58, relocating the gates 50 and retightening the nuts so as to lock the gates in position on the trough 15.

It is known that each particulate materal has a particular angle of repose in a static state, such an angle of repose being designated a in Figure 4 of the drawing. Without the gates 50 in Figure 4, it can be seen that the line 62 representing the one side of the angle of repose of the material overlaps the center opening 18 such that, under the teaching of my '193 patent will permit the material to, at least in part, continue to flow onto the conveyor 33. This flow would be particularly true where the width of the deflector has been reduced to a desired minimum.By providing the adjustable gates 50 on the elongate edges of the center opening 18 and setting the gates so that the upper edges 60 of the gates are above the line 62 defining the angle of repose a of the material will stop the flow of material when the vibration generating apparatus 30 is shut off. Upon starting the vibration apparatus 30 the angle of repose of the material decreases to an extent that the material will flow over the edges 60 of the gate and onto the conveyor.

Access to the adjustments for the gates 50 is relatively simple and can be accomplished without removing the pile material stacked above the apparatus. That is, by loosening the nuts 58, the gates 50 can be forced up or down relative to the trough 15 without difficulty. The upper edges 60 of the gates 50 should be located so that a line drawn from the edges 60 to the edges 24a and 24b of the deflector forms an angle with the horizontal that is less than the static, at rest, angle of repose of the particular particulate material being handled. At rest, the upper surface 62 of the material coincides with the line 62 defining the angle a with the horizontal which is the static angle of repose of the material.The angle B of the line 66 drawn from the edge of the deflector to the top edges 60 of the gates 50 is less than the angle of repose a of the material, in Figure 4, so material will not flow. When the vibratory apparatus is activated, the angle of the surface of the material becomes less than the angle B whereupon the material will flow over the gates 60 onto the conveyor 33.

A feature of the apparatus is that the vibration is horizontal and normal to the longitudinal axis of the trough 15, each sloping side wall 16 and 17 acts as a vibratory feeder, feeding the material carried thereon toward the adjacent edge of the opening 18.

Also, when the vibrator is in operation, vibratory forces are transmitted into the pile 42 of particulate material overlying the opening 11, the primary vibrating forces being along the lines of the arrows 43 which are generally parallel to the internal sheer angles of the material, such sheet angles being themselves generally parallel to the angle of repose of the material at rest. Thus, de-piling freely occurs as the vibrator is actuated, and flow ceases when the vibrator is stopped.

Claims (3)

1. In a vibratory apparatus for delivering particulate material and adapted for use in combination with a base having an aperture therein communicating with a passage beneath the base, said vibratory apparatus comprising a trough having an opening in the bottom thereof with the opening extending from one end of the trough to the other end thereof, said trough having side walls sloping downwardly and inwardly from the side of the trough to said opening, a deflector secured to the trough and extending upwardly therefrom, said deflector having its lower edges spaced from the side walls of the trough and having its center portion located above the opening in the trough, means for mounting said vibratory apparatus in said aperture in the base to support material piled thereover, said mounting means including springs supporting the trough for vibratory movement, a vibration generator secured to said apparatus for vibrating the same in a direction transverse to the direction of extent of the opening, and a conveyor below the opening in the trough to receive material discharged therethrough, the impovement comprising means for controlling flow of material into the elongate opening, said means comprising vertically disposed gates affixed to the elongate edges of the elongate opening, the angle to the horizontal of a line drawn from the top of each gate and the nearest adjacent lower edge of the deflector being less than the static angle of repose of the material.

2. In a vibratory apparatus for delivering particulate material and adapted for use in combination with a base having an aperture therein communicating with a passage beneath the base, said vibratory apparatus comprising an elongated, rectangular trough having an opening in the bottom thereof with the opening extending substantially from one end of the trough to the other end thereof, an end wall at each of said ends of the trough, said trough having side walls sloping downwardly from the sides of the trough to said opening, a deflector secured to the end walls and extending upwardly from the trough, said deflector extending over the entire length of the opening and having its lower edges spaced from the side walls of the trough and having its center portion located above the opening in the trough, the angle to the horizontal of a line extending from the lower edges of the deflector to the adjacent edge of the opening being less than the static angle of repose of the material, means for mounting said vibratory apparatus in said aperture in the base to support material piled thereover, said mounting means including springs supporting the trough for vibratory movement, a vibration generator secured to said apparatus for vibrating the same in a direction transverse to the major axis of the trough, and a conveyor below the opening in the trough to receive material discharged therethrough, the improvement comprising means for controlling flow of material into the elongate opening, said means comprising vertically disposed gates affixed to the elongate edges of the elongate opening, the angle to the horizontal of a line drawn from the top of each gate and the nearest adjacent lower edge of the deflector being less than the static angle of repose of the material, and means for adjusting the height of each gate above the edge of the trough defining the opening whereby the angle to the horizontal of the line drawn from the top of each gate to the nearest adjacent lower edge of the deflector is increased or decreased the necessary amount to be less than the static angle of repose of the material.

3. In a vibratory apparatus for delivering particulate material and adapted for use in combination with a base having an aperture therein communicating with a passage beneath the base, said vibratory apparatus comprisng an elongated rectangular trough having an opening in the bottom thereof with the opening extending from one end of the trough to the other end thereof, said trough having side walls sloping downwardly from the side of the trough to said opening, a deflector secured to the trough, said deflector being in the form of a longitudinal cylindrical section convex upwardly and extending from end to end of the trough, said deflector having its lower edges spaced from the side walls of the trough and having its center portion located above the opening in the trough, means for mounting said vibratory apparatus in said aperture in the base to support material piled thereover, said mounting means including springs supporting the trough for vibratory movement, a vibration generator secured to said apparatus for vibrating the same in a horizontal plane transverse to the extent of the opening, and a conveyor below the opening in the trough to receive material discharged therethrough, the improvement comprising means for controlling flow of material from around the lower edges of said deflector, said means including a pair of vertical gates adjustably secured to the opposite elongate edges of said opening in the trough, the top edge of each gate aligning with the adjoining lower edge of the deflector along a plane forming an angle with the horizontal which is less than the static angle of repose of the material.