Storage / discharge device

Abstract

Provided is a storage / discharge device that can easily exert a bridge prevention effect over all of a storage tank.　The present invention comprises: a storage tank 2 having an insertion port 2a for treated objects provided in an upper section and a discharge port 2b for treated objects provided on one end side of a bottom section; a screw conveyor 3 for transferring treated objects at the bottom section of the storage tank 2 toward the discharge port 2b; and a bridge prevention device 4. The bridge prevention device 4 comprises a stirring screw section 42 rotatable around an axis of rotation extending vertically, a stirring rotation drive unit 43 for rotationally driving the stirring screw section 42, and a horizontal movement mechanism 44 that moves the stirring screw section 42 horizontally.

Description

Storage and discharge device

[0001] The present invention relates to a storage and discharge device for storing and discharging materials to be treated, such as sludge, livestock excrement, and food waste.

[0002] Conventionally, there are known treatment devices used for storing and discharging materials to be treated, such as sludge and food waste. If bridging occurs in the hopper of the treatment device, the materials can be difficult to treat or remove. For this reason, a hopper device (storage and discharge device) with a function to prevent bridging has been proposed (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a hopper device including a storage tank for storing materials to be treated, a screw conveyor for transporting sludge from the storage tank, and bridge prevention plates affixed to the storage tank so that they can swing. The bridge prevention plates are suspended in two rows along the conveying direction of the screw conveyor by chains or the like. The bridge prevention plates distribute the force of the materials attempting to be consolidated toward the bottom of the hopper device, allowing them to fall smoothly onto the screw conveyor below.

[0004] Patent Document 1 also discloses an example in which a diffusion screw is provided between multiple bridge prevention plates along the conveying direction of the screw conveyor. This improves the fluidity of the material to be treated and prevents accumulation and adhesion of the material. Patent Document 1 also discloses providing an air supply port in the storage tank to supply air. This air supply controls the humidity of the material to be treated, thereby reducing the generation of odors.

[0005] Japanese Patent Application Laid-Open No. 2004-352426

[0006] However, the bridge prevention plate of the hopper device of Patent Document 1 is simply suspended by gravity and does not actively move. This poses a problem in that it is difficult to achieve the intended bridge prevention effect. Furthermore, the diffusion screw of Patent Document 1 extends in the longitudinal direction of the screw conveyor and rotates at the same position. Therefore, when a large amount of material is stored above the diffusion screw, the rotation of the diffusion screw is unlikely to affect the upper layer of material stored in the storage tank. Furthermore, in the air supply method of Patent Document 1, when an air supply port is provided on the wall of the storage tank, the air supply has a problem in that it is difficult for the material in the center of the storage tank to be reached.

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a storage and discharge device that can easily exert a bridging prevention effect throughout the entire storage tank.

[0008] The inventions disclosed in this specification to solve the above-mentioned problems are configured as follows: That is, a first invention comprises a storage tank having an inlet for materials to be treated provided at an upper portion and an outlet for the materials to be treated provided at one end side of a bottom portion, a screw conveyor that transports the materials to be treated at the bottom of the storage tank toward the outlet, and a bridging prevention device, wherein the bridging prevention device comprises a stirring screw unit that is rotatable about a rotation axis extending in a vertical direction, a stirring rotation drive unit that rotationally drives the stirring screw unit, and a horizontal movement mechanism that moves the stirring screw unit in a horizontal direction.

[0009] According to the first aspect of the present invention, the agitating screw unit, which is rotatable around a vertically extending rotation axis, is driven by the agitation rotation drive unit, thereby forcibly moving the workpieces stored in the storage tank in the vertical direction of the storage tank. Furthermore, the agitating screw unit is moved horizontally by the horizontal movement mechanism, thereby forcibly moving the workpieces stored in the storage tank in the vertical direction of the storage tank not only at one location but also at multiple locations in the horizontal direction. In other words, the bridging prevention device forcibly agitates the workpieces stored in the storage tank over a wide area in both the vertical and horizontal directions. This prevents the bridging phenomenon from occurring throughout the storage tank. Furthermore, even if the bridging phenomenon does occur, the movement of the agitating screw unit quickly destroys the bridged portions. This allows the bridging prevention effect to be easily achieved throughout the storage tank.

[0010] In a second invention, in the first invention, the stirring rotation drive unit is arranged above the inlet, and the stirring screw unit has a base end connected to the stirring rotation drive unit and a tip end arranged near the upper end of the screw conveyor.

[0011] According to the second aspect of the present invention, the agitation rotation drive unit of the bridging prevention device is disposed above the inlet of the storage tank for the materials to be treated, thereby preventing the agitation rotation drive unit from becoming buried in the materials to be treated being fed through the inlet. This prevents breakdowns of the agitation rotation drive unit. Furthermore, by connecting the base end of the agitation screw unit to the agitation rotation drive unit disposed in this position and disposing the tip end of the agitation screw unit near the top end of the screw conveyor, the vertical length of the agitation screw unit can be made to extend entirely from the inlet to the bottom of the storage tank. This allows the agitation screw unit to agitate the materials to be treated stored in the storage tank entirely from the upper surface to the bottom. This further enhances the bridging prevention effect.

[0012] In a third invention, in the second invention, the screw conveyors are provided in multiple units in parallel horizontally at the bottom of the storage tank, the first screw diameter of the stirring screw section is formed larger than the second screw diameter of the screw conveyor, and the stirring screw section is configured to always overlap with two or more adjacent screw conveyors in a planar view.

[0013] According to the third invention, the stirring screw section can be always positioned above two or more adjacent screw conveyors, thereby preventing stagnation of the treated material in the space between adjacent screw conveyors in the storage tank.

[0014] In a fourth invention, in the third invention, the horizontal movement mechanism includes a first horizontal movement mechanism that moves the stirring screw section in a first direction along the transport direction of the screw conveyor, and a second horizontal movement mechanism that moves the stirring screw section in a second direction that intersects the transport direction of the screw conveyor.

[0015] According to the fourth aspect of the present invention, the first horizontal movement mechanism and the second horizontal movement mechanism can move the agitating screw unit in two intersecting directions on the horizontal plane, allowing the agitating screw unit to be easily moved across the entire horizontal plane of the storage tank. This more reliably prevents bridging by the agitating screw unit. Furthermore, since the agitating screw unit is configured to be movable along the transport direction of the screw conveyor or intersecting the transport direction, cooperation between the agitating screw unit and the screw conveyor can achieve a good balance between transporting the material to the discharge outlet and preventing bridging.

[0016] In a fifth invention, in the fourth invention, the screw conveyor has a first screw conveyor and a second screw conveyor arranged at a position farther away from the discharge outlet than the first screw conveyor, the first screw conveyor and the second screw conveyor are arranged concentrically and with opposing ends close to each other, and the first screw conveyor and the second screw conveyor are configured to be driven independently of each other.

[0017] According to the fifth invention, by linking the first screw conveyor and the second screw conveyor, they can be used not only to move the material to the discharge outlet, but also to keep the material in the storage tank and efficiently mix it.

[0018] According to the storage and discharge device of the present invention, the bridging prevention effect can be easily achieved throughout the entire storage tank.

[0019] 1 is a diagram illustrating the overall configuration of a waste treatment system including an accumulation and discharge device according to one embodiment of the present invention. FIG. 2 is a perspective view of the accumulation and discharge device according to this embodiment. FIG. 3 is a plan view of the accumulation and discharge device according to this embodiment. FIG. 4 is a sectional side view of the accumulation and discharge device according to this embodiment. FIG. 5 is a perspective view of a main part showing a bridging prevention device of the accumulation and discharge device according to this embodiment. FIG. 6 is a side view of the bridging prevention device according to this embodiment. FIG. 7 is a side view showing the relationship between a first screw diameter of the stirring screw unit and a second screw diameter of the screw conveyor in the bridging device according to this embodiment. FIG. 8 is a schematic diagram showing the electrical connection between a control unit and a drive unit of the accumulation and discharge device according to this embodiment. FIG. 9 is a schematic diagram for explaining the operation pattern of the screw conveyor of the accumulation and discharge device according to this embodiment. FIG. 10 is a schematic diagram for explaining the operation pattern of the screw conveyor of the accumulation and discharge device according to this embodiment. FIG. 11 is a schematic diagram for explaining the operation pattern of the stirring screw unit of the bridging prevention device according to this embodiment.

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0021] FIG. 1 is a diagram showing the overall configuration of a waste treatment system 100 equipped with a storage and discharge device 1 according to one embodiment of the present invention.

[0022] The waste treatment system 100 in Fig. 1 is a system that treats livestock excrement (manure) from animals such as cows, pigs, sheep, and chickens. The waste treatment system 100 ferments and dries the livestock excrement. As shown in Fig. 1, the waste treatment system 100 includes a storage and discharge device 1, a fermentation and drying device 10, a boiler device 110, a steam control device 120, and a steam generator 130.

[0023] The storage and discharge device 1 includes a storage tank 2. The storage tank 2 has an inlet 2a for materials to be treated provided at the top and an outlet 2b for materials to be treated provided at one end of the bottom. Materials to be treated transported by a transport vehicle T such as a dump truck or a suction vehicle are introduced into the storage tank 2 through the inlet 2a. The storage and discharge device 1 also includes a plurality of screw conveyors 3 that transport the materials to be treated at the bottom of the storage tank 2 toward the outlet 2b. The materials to be treated in the storage tank 2 are discharged to the outside through the outlet 2b by driving the screw conveyors 3.

[0024] The material to be treated discharged from the discharge port 2b of the storage tank 2 is transferred to the fermentation drying apparatus 10 by a screw conveyor or the like. In the fermentation drying apparatus 10, the material to be treated is subjected to a fermentation drying process. The fermentation drying apparatus 10 comprises an airtight container 11, an agitator 12, and a heating jacket 13. The airtight container 11 is formed to maintain the interior at or below atmospheric pressure. A storage section 11a for storing the material to be treated is formed inside the airtight container 11. An inlet 11b for the material to be treated is provided at the top of the airtight container 11. The agitator 12 is provided to agitate the material to be treated in the storage section 11a.

[0025] The agitator 12 includes an agitator shaft 12a, multiple agitator blades 12b, and a shaft rotation motor 12c. Both ends of the agitator shaft 12a are supported by a pair of end walls of the sealed container 11. A discharge port 11c for the fermented and dried product is provided on one side of the pair of end walls. Multiple agitator blades 12b are attached to the agitator shaft 12a at predetermined intervals in the axial direction of the agitator shaft 12a and extend radially from the agitator shaft 12a. The shaft rotation motor 12c rotates the agitator shaft 12a. A heating jacket 13 is provided to surround the periphery of the peripheral wall of the sealed container 11. The heating jacket 13 is provided to heat the storage section 11a. The material to be treated is introduced through the inlet 11b of the sealed container 11 and agitated by the rotation of the agitator blades 12b of the agitator 12 while being heated by the heating jacket 13. After a predetermined time has elapsed, the fermented and dried product is discharged from the discharge port 11c.

[0026] The fermented and dried material produced in the fermentation and drying apparatus 10 is transported to the boiler apparatus 110 by a screw conveyor or the like. The boiler apparatus 110 uses the fermented and dried material as fuel. The boiler apparatus 110 heats water with thermal energy from the combustion of the fermented and dried material to generate high-temperature steam. The steam generated in the boiler apparatus 110 is supplied to the steam control device 120 via a steam passage as heating steam. The steam control device 120 adjusts the amount of heating steam supplied downstream of the steam control device 120. The steam control device 120 is connected to the heating jacket 13 of the fermentation and drying apparatus 10 via a steam passage. Heating steam is supplied from the steam control device 120 to the heating jacket 13 via the steam passage.

[0027] The steam control device 120 is connected to the steam generator 130 via a steam passage. The steam generator 130 generates electricity using steam supplied from the steam control device 120. The electric power generated by the steam generator 130 is used as electric power for driving the shaft rotation motor 12c of the agitator 12.

[0028] Next, a detailed structure of the storage and discharge device 1 used in the waste treatment system 100 will be described. Fig. 2 is a perspective view of the storage and discharge device 1 according to this embodiment. Fig. 3 is a plan view of the storage and discharge device 1 according to this embodiment.

[0029] As shown in Figures 2 and 3, the storage tank 2 of the storage and discharge device 1 includes a main storage tank 21 having a generally rectangular shape in plan view and a secondary storage tank 22 having a generally rectangular shape in plan view. The secondary storage tank 22 is formed to be smaller than one-fourth the size of the main storage tank 21 in plan view. One side surface of the main storage tank 21 in the short direction in plan view and one side surface of the secondary storage tank 22 in the long direction in plan view are connected to each other. The main storage tank 21 and the secondary storage tank 22 have bottom walls at the same height. The connecting surface between the main storage tank 21 and the secondary storage tank 22 has a large opening that reaches the bottom wall. This opening allows the material to be treated to move smoothly between the main storage tank 21 and the secondary storage tank 22. The upper end of the main storage tank 21 is entirely open, and this opening serves as an inlet 2a. Furthermore, a discharge outlet 2b is formed in the bottom wall of the secondary storage tank 22. The main storage tank 21 and the sub-storage tank 22 are supported by a plurality of legs 5. Hereinafter, the longitudinal direction of the storage tank 2 is defined as the X direction, and the lateral direction of the storage tank 2 is defined as the Y direction.

[0030] A cover 6 is attached to the upper end of the main storage tank 21. The cover 6 has a shape of a roughly right-angled triangle when the main storage tank 21 is viewed from the X direction. The base of the roughly right-angled triangular cover 6 is open and connected to the inlet 2a of the main storage tank 21. The hypotenuse of the roughly right-angled triangular cover 6 is also open, allowing it to receive materials to be treated that are introduced from the transport vehicle T.

[0031] A top plate 22a is attached to the upper end of the secondary reservoir 22. A window 22b is provided in the top plate 22a, and the inside of the secondary reservoir 22 can be seen through the window 22b.

[0032] The screw conveyor 3 is disposed along the bottom wall portions of the main storage tank 21 and the sub-storage tank 22. The screw conveyor 3 has a first screw conveyor 31 and a second screw conveyor 32. The first screw conveyor 31 is disposed on the near side (closer to the discharge outlet 2b) with respect to the discharge outlet 2b. The second screw conveyor 32 is disposed on the farther side than the first screw conveyor 31 with respect to the discharge outlet 2b (farther away from the discharge outlet 2b than the first screw conveyor 31).

[0033] The first screw conveyor 31 and the second screw conveyor 32 are each arranged so that four screw conveyors are parallel to each other in the Y direction. The four screw conveyors constituting the first screw conveyor 31 (the first-A screw conveyor 311, the first-B screw conveyor 312, the first-C screw conveyor 313, and the first-D screw conveyor 314) are each arranged concentrically with the four screw conveyors constituting the second screw conveyor 32 (the second-A screw conveyor 321, the second-B screw conveyor 322, the second-C screw conveyor 323, and the second-D screw conveyor 324).

[0034] The ends of the four screw conveyors 311, 312, 313, and 314 constituting the first screw conveyor 31 are arranged to face closely to the ends of the four screw conveyors 321, 322, 323, and 324 constituting the second screw conveyor 32. The four screw conveyors 311, 312, 313, and 314 constituting the first screw conveyor 31 and the four screw conveyors 321, 322, 323, and 324 constituting the second screw conveyor 32 are configured to be driven independently of each other.

[0035] A plurality of curved grooves 21a are formed along the X direction on the bottom walls of the main storage tank 21 and the sub-storage tank 22 so as to correspond to the first screw conveyor 31 and the second screw conveyor 32. Four curved grooves 21a are provided side by side in the Y direction.

[0036] Four first screw conveyors 31 are attached to the side wall of the auxiliary storage tank 22 opposite the main storage tank 21. Each first screw conveyor 31 has a screw body 31a and a first motor 31b connected to the base end of the screw body 31a via a conveyor reducer 31c. The first motor 31b and conveyor reducer 31c are exposed to the outside of the auxiliary storage tank 22. The screw body 31a of each first screw conveyor 31 is disposed so that its lower half is fitted into each curved groove 21a and extends along the curved groove 21a. The base end of the screw body 31a is located directly above the discharge port 2b. The tip end of the screw body 31a extends to the center of the main storage tank 21 in the X direction.

[0037] Four second screw conveyors 32 are attached to the side wall of the main storage tank 21 opposite the sub-storage tank 22. Each second screw conveyor 32 has a screw body 32a and a second motor 32b connected to the base end of the screw body 32a via a conveyor reducer 32c. The second motor 32b and the conveyor reducer 32c are exposed to the outside of the main storage tank 21. The screw body 32a of each second screw conveyor 32 is disposed so that its lower half is fitted into the corresponding curved groove 21a and extends along the curved groove 21a. The tip of the screw body 32a extends to the center of the main storage tank 21 in the X direction. The two opposing ends of the screw body 31a of the first screw conveyor 31 and the screw body 32a of the second screw conveyor 32, which are fitted into the same curved groove 21a, are disposed close to each other.

[0038] FIG. 4 is a cross-sectional side view of the storage and discharge device 1 according to this embodiment. As shown in FIGS. 3 and 4 , the secondary storage tank 22 is provided with a discharge port pushing rotor 7 extending in the Y direction. The discharge port pushing rotor 7 is disposed directly above the discharge port 2b and in a position adjacent to and above the four first screw conveyors 31. The discharge port pushing rotor 7 pushes out the material to be treated, which has been transferred toward the discharge port 2b by the four first screw conveyors 31, so that the material is discharged from the discharge port 2b without escaping upward into the storage tank 2 (secondary storage tank 22). The discharge port pushing rotor 7 has a rotating shaft 7a and multiple blades 7b. Both ends of the rotating shaft 7a are supported by the side walls of the secondary storage tank 22. Multiple blades 7b are attached to the rotating shaft 7a at predetermined intervals along the longitudinal direction of the rotating shaft 7a. One end of the rotating shaft 7a passes through the side wall of the secondary storage tank 22 and is connected to the extrusion rotation drive unit 8 outside the secondary storage tank 22. The extrusion rotation drive unit 8 has a motor 8a for the extrusion rotor and a reducer 8b for the extrusion rotor. The discharge port extrusion rotor 7 is driven to rotate by the driving of the motor 8a for the extrusion rotor.

[0039] FIG. 5 is a perspective view of a main portion of the bridging prevention device 4 of the storage and discharge device 1 according to this embodiment. FIG. 6 is a side view of the bridging prevention device 4 according to this embodiment. As shown in FIGS. 3 to 6 , the storage and discharge device 1 includes a bridging prevention device 4 for preventing bridging of the materials stored in the storage tank 2 or for eliminating any bridging that has occurred. The bridging prevention device 4 includes an agitation screw unit 42 that is rotatable about a vertically extending rotation axis, an agitation rotation drive unit 43 that drives the agitation screw unit 42 to rotate, a main frame unit 41, and a horizontal movement mechanism 44 that moves the agitation screw unit 42 horizontally. The bridging prevention device 4 receives power from a power supply cable 4a suspended by a cable suspension unit 6a of the cover unit 6 (see FIGS. 2 and 4 ).

[0040] The agitation rotation drive unit 43 is disposed above the feed port 2a. In this embodiment, the central axis of the agitation screw unit 42 extends vertically. The base end of the agitation screw unit 42 is connected to the agitation rotation drive unit 43. The tip end of the agitation screw unit 42 is disposed near the upper end of the screw conveyor 3. The agitation rotation drive unit 43 has an agitation motor 431 and an agitation reducer 432.

[0041] The main frame 41 includes a pair of short-side members 411, 411, a connecting member 412, a roller shaft mounting bracket 413, and a pinion shaft bearing 414. The short-side members 411 are channel members with a U-shaped cross section. The short-side members 411 extend horizontally in the Y direction and are arranged in pairs at a predetermined interval in the X direction. The pair of short-side members 411, 411 are formed to a length sufficient to bridge between the side walls of the main storage tank 21 facing each other in the Y direction. The pair of short-side members 411, 411 are arranged so that the recesses of the U-shaped cross sections face each other. The connecting member 412 is a strip-shaped member that connects the pair of short-side members 411, 411 together and extends horizontally in the X direction. A plurality of connecting members 412 are provided to prevent deviation in the interval between the pair of short-side members 411, 411.

[0042] A plurality of roller shaft mounting brackets 413 are attached to the side surface of each short side member 411 that faces the side wall of the storage tank 2 in the X direction. The roller shaft mounting brackets 413 are also attached to both end positions of the short side member 411 in the Y direction. A plurality of pinion shaft bearings 414 are attached to the side surface of the short side member 411 that faces the side wall of the storage tank 2 in the X direction. The pinion shaft bearings 414 are also attached to three locations: both end positions and the center of the short side member 411 in the Y direction. When the positions of the tip ends of the roller shaft mounting brackets 413 and the pinion shaft bearings 414 are compared, the position of the tip end of the roller shaft mounting bracket 413 protrudes outward in the X direction more than the position of the tip end of the pinion shaft bearings 414.

[0043] The horizontal movement mechanism 44 includes a first horizontal movement mechanism 45 that moves the stirring screw section 42 in a first direction (X direction) along the transport direction of the screw conveyor 3, and a second horizontal movement mechanism 46 that moves the stirring screw section 42 in a second direction (Y direction) perpendicular to the transport direction of the screw conveyor 3.

[0044] The first horizontal movement mechanism 45 includes a pair of rail members 451, 451, a pair of first rack members 452, 452, a pair of first roller shafts 453, 453, a pair of first pinion shafts 454, 454, a longitudinal movement motor 455, and a first reducer 456. The pair of rail members 451, 451 are channel members with a U-shaped cross section and are attached to the upper end of each inner surface of two side walls of the main storage tank 21 extending in the X direction. The pair of rail members 451, 451 are attached so as to extend horizontally along the upper edge of the main storage tank 21. The pair of rail members 451, 451 are also attached so that the recesses of the U-shaped cross sections face each other. The pair of first rack members 452, 452 are each attached to the upper inner wall surface of the rail member 451 so as to extend along the rail member 451.

[0045] One of the pair of first pinion shafts 454, 454 is rotatably supported by a pinion shaft bearing 414 attached to one of the pair of short direction members 411, 411. The first pinion shaft 454 on one side is disposed adjacent to the short direction member 411 on one side and extends along the short direction member 411 on one side. The other of the pair of first pinion shafts 454, 454 is rotatably supported by a pinion shaft bearing 414 attached to the other of the pair of short direction members 411, 411. The other first pinion shaft 454 is disposed adjacent to the short direction member 411 on the other side and extends along the short direction member 411 on the other side. Each first pinion shaft 454 has a shaft body 454a rotatably supported by the pinion shaft bearing portion 414, and first pinion portions 454b, 454b attached to both ends of the shaft body 454a. Each of the first pinion portions 454b, 454b at both ends is configured to mesh with a corresponding first rack member 452. A first pinion shaft sprocket 454c is attached to one side of the pair of first pinion shafts 454, 454.

[0046] The longitudinal movement motor 455 is attached to the short-side member 411 of the main body frame 41 via a bracket. A first reducer 456 is connected to the longitudinal movement motor 455. A first reducer-side sprocket 456a is attached to the output shaft of the first reducer 456. A first chain 457 is stretched between the first reducer-side sprocket 456a and the first pinion-shaft-side sprocket 454c of the first pinion shaft 454. The first chain 457 is covered by a first chain case 458.

[0047] One of the pair of first roller shafts 453 supports the tip of a roller shaft mounting bracket 413 attached to one of the pair of short direction members 411. The first roller shaft 453 on one side is disposed adjacent to the first pinion shaft 454 on one side and extends along the first pinion shaft 454 on one side. The first roller shaft 453 on one side is disposed outward of the first pinion shaft 454 on one side with respect to the short direction member 411 on one side. The other of the pair of first roller shafts 453 supports the tip of the roller shaft mounting bracket 413 attached to the other of the pair of short direction members 411. The other first roller shaft 453 is disposed adjacent to the first pinion shaft 454 on the other side and extends along the first pinion shaft 454 on the other side. The first roller shaft 453 on the other side is disposed further outward than the first pinion shaft 454 on the other side with respect to the short-side member 411 on the other side.

[0048] Each first roller shaft 453 has a shaft body 453a that supports the tip end of the roller shaft mounting bracket 413, and first roller portions 453b rotatably attached to both ends of the shaft body 453a. The first roller portions 453b, 453b at both ends abut against the lower inner wall surfaces of the corresponding rail members 451. In other words, the pair of first roller shafts 453, 453 are supported by the pair of rail members 451, 451. As a result, the weight of the bridge prevention device 4, excluding the pair of rail members 451, 451 and the pair of first rack members 452, 452, is supported by the pair of rail members 451, 451.

[0049] The second horizontal movement mechanism 46 includes a base member 461, a pair of second rack members 462, 462, a pair of second roller shafts 463, 463, a pair of second pinion shafts 464, 464, a lateral movement motor 465, and a second reducer 466. The base member 461 is formed by combining metal plates. The base member 461 includes a substantially rectangular parallelepiped box portion 461a and multiple support brackets 461b. The support brackets 461b are provided on each of a pair of Y-direction side walls of the box portion 461a so as to protrude outward in the Y-direction. An agitation reducer 432 of the agitation rotation drive unit 43 is attached to the top wall of the box portion 461a. The output shaft of the agitation reducer 432 of the agitation rotation drive unit 43 is provided at the position of the upper and lower through-holes of the box portion 461a. The base end of the stirring screw portion 42 is attached to the output shaft of the stirring reducer 432 .

[0050] As shown in FIG. 6 , the box portion 461a supports a pair of second pinion shafts 464, 464 aligned in the Y direction. Specifically, the pair of second pinion shafts 464, 464 extend in the X direction and penetrate the side wall of the box portion 461a. A second pinion portion 464b is provided at both ends of each second pinion shaft 464. As shown in FIGS. 5 and 6 , a second pinion shaft sprocket 464c is attached to one of the pair of second pinion shafts 464, 464 at a position inside the box portion 461a. A window portion 461c is provided in the top wall of the box portion 461a, directly above the second pinion shaft sprocket 464c. A second reducer 466 is attached to the top wall of the box portion 461a adjacent to the window portion 461c. A lateral direction movement motor 465 is connected to the second reducer 466. A second reduction gear sprocket 466a is attached to the output shaft of the second reduction gear 466. A second chain 467 is stretched between the second reduction gear sprocket 466a and the second pinion shaft sprocket 464c through a window 461c. The second chain 467 is covered by a second chain case 468.

[0051] The pair of second rack members 462, 462 are each attached to the upper inner wall surface of the short-side direction member 411 having a U-shaped cross section so as to extend along the short-side direction member 411. The pair of second pinion shafts 464, 464 are each configured so that second pinion portions 464b at both ends mesh with the corresponding second rack members 462.

[0052] Each of the pair of second roller shafts 463, 463 is supported by a support bracket 461b so as to be adjacent to the Y-direction sidewall of the box portion 461a and extend in the X-direction. More specifically, the second roller shaft 463 has a shaft body 463a and second roller portions 463b rotatably attached to both ends of the shaft body 463a. The support bracket 461b supports the shaft body 463a of the second roller shaft 463. Each of the second roller portions 463b, 463b at both ends of the second roller shaft 463 abuts against the lower inner wall surface of the corresponding short-side member 411. The second roller shaft 463 is supported by the short-side member 411. As a result, the weight of the base member 461, the agitation rotation drive unit 43, the agitation screw unit 42, the short-side movement motor 465, the second reducer 466, etc. is supported by the short-side member 411.

[0053] In the bridge prevention device 4 configured as described above, when the agitation motor 431 is driven to rotate, the agitation screw unit 42 is driven to rotate. By switching the rotation direction of the agitation motor 431, the agitation screw unit 42 can move the workpiece stored in the storage tank 2 either upward (in the Z1 direction in FIG. 6 ) or downward (in the Z2 direction in FIG. 6 ). Furthermore, when the longitudinal movement motor 455 of the first horizontal movement mechanism 45 is driven to rotate, one of the first pinion shafts 454 is driven to rotate, and the rotational drive force is transmitted to the first rack member 452 via the first pinion unit 454b. This causes the main body frame unit 41 and the second horizontal movement mechanism 46 to move in the X direction together with the agitation screw unit 42. Furthermore, when the lateral direction movement motor 465 of the second horizontal movement mechanism 46 is rotationally driven, one of the second pinion shafts 464 is rotationally driven, and the rotational drive force is transmitted to the second rack member 462 via the second pinion portion 464b. As a result, the base member 461 is moved in the Y direction together with the stirring screw portion 42.

[0054] FIG. 7 is a side view showing the relationship between the first screw diameter D1 of the stirring screw unit 42 and the second screw diameter D2 of the screw conveyor 3 in the bridging prevention device 4 according to this embodiment. As shown in FIG. 7 , the first screw diameter D1 of the stirring screw unit 42 according to this embodiment is larger than the second screw diameter D2 of the screw conveyor 3. More specifically, the first screw diameter D1 of the stirring screw unit 42 according to this embodiment is set to be approximately 1.8 times the second screw diameter D2 of the screw conveyor 3. Furthermore, the stirring screw unit 42 is configured to always overlap two or more adjacent screw conveyors 3 in a plan view (see FIG. 3 ). As a result, when the stirring screw unit 42 is moved in the Y direction, the blade portion of the stirring screw unit 42 is positioned directly above one of the screw conveyors 3, regardless of the position of the stirring screw unit 42.

[0055] 8 is a schematic diagram showing the electrical connection between the control unit 9 and the drive units of the storage and discharge device 1 according to this embodiment. As shown in FIG. 8, the storage and discharge device 1 according to this embodiment includes a control unit 9 for controlling the operation of each drive unit. The control unit 9 is electrically connected to the first A motor 311b for driving the first A screw conveyor 311, the first B motor 312b for driving the first B screw conveyor 312, the first C motor 313b for driving the first C screw conveyor 313, and the first D motor 314b for driving the first D screw conveyor 314. The control unit 9 is also electrically connected to the second A motor 321b for driving the second A screw conveyor 321, the second B motor 322b for driving the second B screw conveyor 322, the second C motor 323b for driving the second C screw conveyor 323, and the second D motor 324b for driving the second D screw conveyor 324.

[0056] The control unit 9 is also electrically connected to the pusher rotor motor 8a that rotates the discharge port pusher rotor 7. The control unit 9 is also electrically connected to the stirring motor 431 that rotates the stirring screw unit 42 of the bridge prevention device 4, the longitudinal movement motor 455 that drives the first horizontal movement mechanism 45 of the bridge prevention device 4, and the lateral movement motor 465 that drives the second horizontal movement mechanism 46 of the bridge prevention device 4. The control unit 9 performs sequence control of each motor based on pre-programmed content.

[0057] 9A, 9B, and 9C are schematic diagrams illustrating the operation pattern of the screw conveyor 3 of the storage and discharge device 1 according to this embodiment. The storage and discharge device 1 according to this embodiment includes a first screw conveyor 31, which includes a first-A screw conveyor 311, a first-B screw conveyor 312, a first-C screw conveyor 313, and a first-D screw conveyor 314. The storage and discharge device 1 also includes a second screw conveyor 32, which includes a second-A screw conveyor 321, a second-B screw conveyor 322, a second-C screw conveyor 323, and a second-D screw conveyor 324. The most basic function of these is to transport the materials to be treated in the storage tank 2 toward the discharge port 2b so that all of the materials to be treated are discharged from the discharge port 2b. In this case, as shown in FIG. 9A, the control unit 9 controls the rotation of the first A motor 311b, the first B motor 312b, the first C motor 313b, the first D motor 314b, the second A motor 321b, the second B motor 322b, the second C motor 323b and the second D motor 324b so that the transport direction of the workpiece is all in the X1 direction.

[0058] However, the materials to be treated may not be discharged immediately after being introduced into the storage tank 2, but may remain stored there for some time. In this case, a bridging phenomenon is likely to occur. Furthermore, the interior of the materials to be treated may become anaerobic, causing an intensified odor. Therefore, in this embodiment, the control unit 9 can control the transport directions of the first screw conveyors 311, 312, 313, and 314 and the second screw conveyors 321, 322, 323, and 324 to agitate the materials to be treated stored in the storage tank 2. For example, as shown in FIG. 9B , the control unit 9 controls the rotation of the first B motor 312b, the first D motor 314b, the second B motor 322b, and the second D motor 324b so that the transport direction of the materials to be treated is the X1 direction. Meanwhile, the control unit 9 controls the rotation of the first A motor 311b, the first C motor 313b, the second A motor 321b, and the second C motor 323b so that the transport direction of the workpiece is the X2 direction. This control agitates the workpiece near the bottom of the storage tank 2.

[0059] 9B 。 Also, the control unit 9 can perform control other than that shown in FIG. 9B depending on the situation. For example, as shown in FIG. 9C , the control unit 9 controls the rotation of the first A motor 311b, the first B motor 312b, the first C motor 313b, and the first D motor 314b so that the transfer direction of the workpiece is the X1 direction. On the other hand, the control unit 9 controls the rotation of the second A motor 321b, the second B motor 322b, the second C motor 323b, and the second D motor 324b so that the transfer direction of the workpiece is the X2 direction.

[0060] 10A and 10B are schematic diagrams illustrating the operation pattern of the agitation screw unit 42 of the bridging prevention device 4 according to this embodiment. The control for agitating the workpieces using the first screw conveyors 311, 312, 313, and 314 and the second screw conveyors 321, 322, 323, and 324 described above can agitate the workpieces near the bottom of the storage tank 2. However, this control does not agitate the workpieces in the middle and upper layers of the storage tank 2, and is insufficient to suppress or eliminate the bridging phenomenon. Therefore, in this embodiment, the control unit 9 moves the agitation screw unit 42 of the bridging prevention device 4 in the main storage tank 21 in a predetermined operation pattern, thereby enabling agitation of the workpieces in the middle and upper layers throughout the main storage tank 21.

[0061] Specifically, as shown in Fig. 10A, for example, the control unit 9 controls the stirring screw unit 42 to mainly move in the Y direction. The control unit 9 controls the stirring screw unit 42 in a zigzag operation pattern, such that the stirring screw unit 42 is moved to one end in the Y direction, then slightly moved in the X direction, and then moved to the other end in the Y direction. Also, as shown in Fig. 10B, for example, the control unit 9 controls the stirring screw unit 42 to mainly move in the X direction. The control unit 9 controls the stirring screw unit 42 in a zigzag operation pattern, such that the stirring screw unit 42 is moved to one end in the X direction, then slightly moved in the Y direction, and then moved to the other end in the X direction. By combining and coordinating the drive control of the above-mentioned first screw conveyors 311, 312, 313, 314 and second screw conveyors 321, 322, 323, 324 with the movement control of the stirring screw section 42, it is possible to stir the entire material to be treated stored in the storage tank 2, thereby suppressing the occurrence of the bridging phenomenon or eliminating the bridging phenomenon.

[0062] As described above, the storage and discharge device 1 according to the above embodiment includes a storage tank 2 having an inlet 2a for materials to be treated provided at the top and an outlet 2b for materials to be treated provided at one end of the bottom, a screw conveyor 3 that transports the materials to be treated at the bottom of the storage tank 2 toward the outlet 2b, and a bridging prevention device 4. The bridging prevention device 4 includes an agitating screw unit 42 that is rotatable about a rotation axis that extends in the vertical direction, an agitation rotation drive unit 43 that drives the agitating screw unit 42 to rotate, and a horizontal movement mechanism 44 that moves the agitating screw unit 42 in the horizontal direction.

[0063] According to the above configuration, the agitation screw unit 42, which is rotatable around a vertically extending rotation axis, is driven by the agitation rotation drive unit 43, thereby forcibly moving the workpieces stored in the storage tank 2 in the vertical direction of the storage tank 2. Furthermore, the agitation screw unit 42 is moved horizontally by the horizontal movement mechanism 44, thereby forcibly moving the workpieces stored in the storage tank 2 in the vertical direction of the storage tank 2 not only at one location but also at multiple locations in the horizontal direction. In other words, the bridging prevention device 4 forcibly agitates the workpieces stored in the storage tank 2 over a wide area in both the vertical and horizontal directions. This prevents the bridging phenomenon from occurring throughout the storage tank 2. Even if the bridging phenomenon does occur, the movement of the agitation screw unit 42 quickly destroys the bridged portions. This allows the bridging prevention effect to be easily achieved throughout the storage tank 2.

[0064] The stirring rotation drive unit 43 is disposed above the feed opening 2 a. The stirring screw unit 42 has a base end connected to the stirring rotation drive unit 43 and a tip end disposed near the upper end of the screw conveyor 3.

[0065] According to the above configuration, the agitation rotation drive unit 43 of the bridging prevention device 4 is positioned above the inlet 2a of the storage tank 2 for the materials to be treated, thereby preventing the agitation rotation drive unit 43 from becoming buried in the materials to be treated introduced through the inlet 2a. This prevents malfunction of the agitation rotation drive unit 43. Furthermore, by connecting the base end of the agitation screw unit 42 to the agitation rotation drive unit 43 positioned in this manner and disposing the tip end of the agitation screw unit 42 near the upper end of the screw conveyor 3, the vertical length of the agitation screw unit 42 can be extended from the inlet 2a of the storage tank 2 to the entire bottom. This allows the agitation screw unit 42 to agitate the materials to be treated in the storage tank 2 from the upper surface to the entire bottom. This further enhances the bridging prevention effect.

[0066] A plurality of screw conveyors 3 are provided in parallel in the horizontal direction on the bottom of the storage tank 2. The first screw diameter D1 of the stirring screw section 42 is larger than the second screw diameter D2 of the screw conveyor 3. The stirring screw section 42 is configured to always overlap with two or more adjacent screw conveyors 3 in a plan view.

[0067] According to the above configuration, the stirring screw section 42 can always be positioned above two or more adjacent screw conveyors 3, thereby preventing stagnation of the treated material in the space between adjacent screw conveyors 3 within the storage tank 2.

[0068] The horizontal movement mechanism 44 also includes a first horizontal movement mechanism 45 that moves the stirring screw section 42 in a first direction along the transport direction of the screw conveyor 3, and a second horizontal movement mechanism 46 that moves the stirring screw section 42 in a second direction perpendicular to the transport direction of the screw conveyor 3.

[0069] According to the above configuration, the first horizontal movement mechanism 45 and the second horizontal movement mechanism 46 can move the agitating screw unit 42 in two mutually orthogonal directions on the horizontal plane, so that the agitating screw unit 42 can be easily moved across the entire horizontal plane of the storage tank 2. This more reliably enables the agitating screw unit 42 to exert its bridging prevention effect. Furthermore, because the agitating screw unit 42 is configured to be movable along the transport direction of the screw conveyor 3 or orthogonal to the transport direction, cooperation between the agitating screw unit 42 and the screw conveyor 3 can provide a balanced effect between transporting the material to the discharge port 2b and the bridging prevention effect.

[0070] The screw conveyor 3 also includes a first screw conveyor 31 and a second screw conveyor 32 that is disposed at a position farther away from the discharge port 2b than the first screw conveyor 31. The first screw conveyor 31 and the second screw conveyor 32 are disposed concentrically and with opposing ends close to each other. The first screw conveyor 31 and the second screw conveyor 32 are configured to be driven independently of each other.

[0071] According to the above configuration, by linking the first screw conveyor 31 and the second screw conveyor 32, they can be used not only to move the material to be treated to the discharge outlet 2b, but also to keep the material to be treated in the storage tank 2 and efficiently mix it.

[0072] The embodiments disclosed herein are illustrative in all respects and are not intended to be limiting. The technical scope of the present invention is not interpreted solely by the above-described embodiments, but is defined by the claims. The technical scope of the present invention also includes all modifications within the scope and meaning equivalent to the claims.

[0073] For example, in the above embodiment, the central axis of the stirring screw portion 42 is configured to extend in the vertical direction. However, the present invention is not limited to this, and the central axis of the stirring screw portion may be configured to extend in the vertical direction at an angle.

[0074] In the above embodiment, the horizontal movement mechanism 44 includes the first horizontal movement mechanism 45 that moves the stirring screw unit 42 in a first direction along the transfer direction of the screw conveyor 3, and the second horizontal movement mechanism 46 that moves the stirring screw unit 42 in a second direction perpendicular to the transfer direction of the screw conveyor 3. However, the present invention is not limited to this, and the first horizontal movement mechanism and the second horizontal movement mechanism may be configured to move the stirring screw unit in two intersecting directions that are not perpendicular to each other. Industrial application fields

[0075] The present invention is applicable to a storage and discharge device that can easily exert a bridging prevention effect over the entire storage tank.

[0076] REFERENCE SIGNS LIST 1 Storage and discharge device 2 Storage tank 2a Inlet 2b Discharge port 3 Screw conveyor 4 Bridge prevention device 42 Mixing screw section 43 Mixing rotation drive section 44 Horizontal movement mechanism 45 First horizontal movement mechanism 46 Second horizontal movement mechanism 31 First screw conveyor 32 Second screw conveyor D1 First screw diameter D2 Second screw diameter

Claims

1. A storage and discharge device comprising: a storage tank having an inlet for material to be treated at the top and an outlet for the material to be treated at one end of the bottom; a screw conveyor which transports the material to be treated at the bottom of the storage tank toward the outlet; and a bridge prevention device, the bridge prevention device comprising: a stirring screw section which is rotatable about a rotation axis which extends in the vertical direction; a stirring rotation drive section which drives the stirring screw section to rotate; and a horizontal movement mechanism which moves the stirring screw section in the horizontal direction.

2. The storage and discharge device as described in claim 1, characterized in that the stirring rotary drive unit is arranged above the inlet, and the stirring screw unit has a base end connected to the stirring rotary drive unit and a tip end arranged near the upper end of the screw conveyor.

3. The storage and discharge device described in claim 2, characterized in that a plurality of the screw conveyors are provided in parallel horizontally at the bottom of the storage tank, a first screw diameter of the stirring screw section is formed larger than a second screw diameter of the screw conveyor, and the stirring screw section is configured to always overlap with two or more adjacent screw conveyors in a planar view.

4. The storage and discharge device described in claim 3, characterized in that the horizontal movement mechanism comprises: a first horizontal movement mechanism that moves the mixing screw section in a first direction along the transport direction of the screw conveyor; and a second horizontal movement mechanism that moves the mixing screw section in a second direction intersecting the transport direction of the screw conveyor.

5. The storage and discharge device described in claim 4, characterized in that the screw conveyor has a first screw conveyor and a second screw conveyor arranged at a position farther away from the discharge outlet than the first screw conveyor, the first screw conveyor and the second screw conveyor are arranged concentrically and with opposing ends adjacent to each other, and the first screw conveyor and the second screw conveyor are configured to be driven independently of each other.

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