JPH01130768A - Apparatus for sorting particulate material - Google Patents

Abstract

PURPOSE: To efficiently sort powder and granular materials, such as radioactive waste, by grain sizes, by providing the inside of a perforated sorting cylinder bored with sorting holes smaller in diameter on a support port side and successively stepwise larger in the diameter toward a discharge port side on the peripheral wall surfaces with concentric and radical partition plates and freely rotatably installing this sorting cylinder so as to incline toward the inside of the cylinder. CONSTITUTION: The powder and granular materials (for example, radioactive waste) 2 mingled with the granular materials of different diameters generated within a nuclear power plant or the like flow down from the lower part of a hopper 1 into the perforated sorting cylinder 6 under rotation within a cylindrical body 5. These materials are divided to a plurality by the partition plats 9a of the inside cylinder 9 and flow down along the circumferential wall. At this time, the pulverulent body of the small outside diameter passes and drops from the sorting holes 8a in a first sorting section 7a and is collected in a pulverulent body hopper 10. In the next second sorting section 7b, the small granular materials of a small size failing to the removed in the first sorting section 7a are sorted and are collected in a small granular material hopper 11. Further, the large granular materials remaining without dropping in both sorting sections 7a, 7b are dropped and collected from a discharge port 6b in a large granular material hopper 12.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application! [!f)] The present invention is aimed at treating 1'7 wastes of radioactive waste generated in one run of nuclear power generation, etc. Regarding separate equipment.

<t; Current technology) Various radioactive wastes generated in equipment handling radioactive materials such as nuclear power plants are sorted according to their properties and then processed or stored. Among these radioactive wastes, waste sludge, waste resin, and concentrated waste liquid are dried in a thin film dryer and processed into powder with a moisture content below a predetermined level.

This powder is further solidified and granulated using a granulator, formed into pellets, and stored in a Pere-Soto storage tank to prevent radioactivity dissipation and attenuate radioactivity. .

(Problems to be Solved by the Invention) In granulating equipment for powdered radioactive waste, etc., the particle size of the pellets varies during molding, and defective pellets with too small particle sizes and powder generated during molding occur. Mixed. Therefore, these defective pellets and powder must be collected and reprocessed to rebuild the pellets. Furthermore, when the molded pellets are transferred to a pellet storage tank by a belt conveyor or the like, defective pellets may crack or powder may scatter, so a device for collecting and re-molding the powder is also required. For this reason, it is necessary to screen the pellets for quality prior to storage.

In addition, even if the pellets are of good quality but have a single particle size, when stored in a pellet storage tank, gaps will be created between the pellets, which will reduce the filling efficiency. 111? It is necessary to increase the size of handling related auxiliary equipment.

Figure 3 is a perspective view of the rotary porous wall cylinder of a conventional sorting device.
The powder and granular material 2 is supplied from the supply hopper 1 into the inside of a rotary porous Aj cylinder 3 installed at an angle, and this is rotated to cause the powder and granular material 2 to flow in an avalanche shape within the rotary porous wall cylinder 3. Powder 2 smaller than the hole 4 is passed through a hole 4 drilled in the surrounding wall, and larger powder 2 is passed through the rotary multi-wall cylinder 3 and taken out from below to be sorted by particle size. ing.

In this zero sorting device, the powder and granules 2 are thrown a lot, so the flow on the inner surface of the rotary porous wall cylinder 3 becomes faster, which lowers the density of the powder and granules 2 on the sorting surface where the holes 4 are located, reducing the sorting efficiency. The drawback is that it drops dramatically.

The purpose of the present invention is to divide the pore diameter of a rotary porous cylinder into multiple parts and further divide the inside to slow down the flow rate when sorting powder and granular materials by particle size, and to improve sorting efficiency and separate pellets by particle size. An object of the present invention is to provide a particle sorting device that can reduce the size of the storage tank and handling related auxiliary equipment by charging it into the storage tank.

[Fjζ Formation of the Invention] (Means for Solving the Problem) Inside a housing provided with a supply port on one side, a cylindrical shape is provided on the surrounding wall surface with a diameter smaller on the supply port side and facing toward the other discharge port side. A multi-hole wall sorting tube is provided with a large number of gradually larger sorting holes, and the inside thereof is partitioned by an inner tube having radial partition plates.The tube is tilted and rotatably installed. A hopper is installed along the lower end of the porous wall sorting tube and along the porous wall sorting tube, corresponding to the diameter of the sorting hole, and a pipe provided with an opening valve is attached to each of the hoppers to be drawn out of the housing.

(Function) Powder and granules that are not fed into one side of the porous wall sorting tube enter the compartment partitioned by the inner tube, and the granules with a smaller diameter than the sorting hole on the inner wall facing each pass through, and the larger granules are successively separated. are sorted out,
The remainder is stored in the final hopper. At this time, the powder and granules are divided into narrow sections within the sorting area of the porous holes 51, so the falling impact during rotation is small, and the flow rate is slow, so there is little damage to the granules, and moreover, the density on the sorting surface can be maintained at a high level. The hopper closest to the supply side 1 collects the powder and the nearest broken granules, and the hopper in the pond collects granules with uniform particle sizes. By operating each on-off valve, a desired amount of powder and granular material of a desired particle size can be delivered to the pellet storage tank in each hopper.

(Example) The actuality of the present invention! An example will be explained with reference to the drawings.

FIG. 1 is a sectional view showing the structure of the present invention, and FIG. 2 is a partially cutaway perspective view of a porous wall sorting tube. Note that the same parts as in the conventional example described above are given the same reference numerals and detailed explanations will be omitted.

A supply hopper 1 for temporarily storing the powder and granular material 2 and supplying it into the housing 5 is installed in the upper part of the housing 5. Inside the casing 5, there is a small-diameter sorting hole 8a with a cylindrical peripheral wall surface as a first sorting section 7a on the supply port 16a side, and a second sorting section 7 on the discharge port 6b side.
A porous wall sorting tube 6 is provided with a plurality of sorting holes 8b each having a larger diameter than the sorting hole 8a as h, and is provided with radial partition plates 9a inside, and an inner tube 9 that divides into a plurality of sections. of,
Supply [”6aI! ! The li is installed at a high inclination so that it can rotate freely. This porous wall sorting cylinder 6 has a rotating shaft 6C driven by a drive device (not shown).

Along the porous wall sorting cylinder 6, a powder hopper 10, a small particle hopper 11, and a large particle hopper 12 are installed under the first sorting section 7a, the second sorting section 7b, and the discharge port 6b, respectively. From the bottom of each hopper 10.11.12, there is an on-off valve 13.
Pipes 16, 17, and 18 with pipes 14, 15, and 18 are led out of the housing 5, and the pipe 16 is connected to a granulation device (not shown), and the pipes 17 and 18 are connected to a pellet storage tank 19. .

Next, the operation of the above configuration will be explained. Porous wall sorting tube 6
While rotating and stirring, fJl (feed hopper) is filled with powder 2 containing a mixture of particles with different diameters.

The powder 2 flows down from the lower part of the supply hopper 1 into the porous wall sorting cylinder 6, is divided into a plurality of parts by the partition plate 9a of the inner cylinder 9, and flows down along the surrounding wall surface. At this time, the porous wall portion 6 is rotating, so the powder and granular material 2 is connected to the surrounding wall surface, the inner cylinder 9, and the partition plate 9.
The powder and granular material 2 that is vertically agitated between the hopper 2 and the granular material 2 that passes through the sorting holes 8a and 8b formed in the surrounding wall surface is accumulated in the hopper at the bottom.

At this time, first in the first sorting section 7a, the sorting hole 8a
Powder with a smaller outer diameter and granules damaged during molding pass through the jXX forming hole a and are collected in the powder hopper 10, and are then removed by the first sorting section 7a in the second sorting section 7b. The small particles that were not removed are sorted and sent to the small particle hopper 1.
collected in 1.

In addition, the large 117-body hopper 12 has the first one. Second sorting section 7
In a and 7b, large particles that did not fall and remained in the porous wall sorting tube 6 fall and accumulate through the discharge port 6b, and as a result, the powder and granules 2 are divided into powder, broken particles, small particles, and large particles. 3
At this time, the flow of the powder and granular material 2 inside the multi-layer (bz separate 06) is obstructed by the separation LIJ plate 921, and the speed from the supply port 6a to the discharge port 6b becomes slow. Therefore, the density of the powder and granular material 2 near the sorting holes 8a and 8b can be maintained high, so that the sorting part yqg is extremely improved and there is less damage to the pellets. Since .12 is surrounded by the casing 5, dust will not be scattered outside, and the casing and piping 16, 17.
By shielding 18, it becomes possible to easily prevent exposure to radioactivity.

The pellets are transferred to the pellet storage tank 19 using til! (
By alternately operating the on-off valves 14 and 15 from the ear device 20, small pellets and large pellets are accommodated alternately, and the gaps between large pellets are filled with small pellets I, improving filling efficiency. .

Further, the powder in the powder hopper 10 is separately sent to a granulating device and re-molded, and then sorted from the supply hopper 1.

Note that the example shows the case where there are two sorting sections, but by increasing the number of sorting sections, particle size
This makes it easier to reduce the amount of water stored in the tank, and the filling efficiency in the Beretsu I storage tank 19 can be further improved.

[Effects of the Invention] As described above, according to the present invention, it is easy to sort radioactive waste pellets based on their shape and particle size, and it is also efficient.
Since the filling efficiency can be improved during storage, it is possible to reduce the scale of installation of storage tanks and auxiliary equipment related to removal plates.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of the sorting device of the present invention, FIG. 2 is a partially cutaway perspective view of a porous wall sorting tube, and FIG. 3 is a perspective view of a rotary porous wall tube part from TiC. l... Supply bottling tube 2... Powder 5... Housing 6... Porous wall sorting tube 6, -Le 1 glue inlet 6b... Discharge port 7; 1
...first sorting section 71)...second sorting section 8a
, 8h...Selection hole °9...Inner cylinder 9a...
Partition plate 10--Powder hopper 11...Small granule hopper 12...Large granule hopper 1
3.14.15...Opening/closing valve [5,17,18...Piping 19...Bellet storage tank.

Claims (4)

[Claims] (1) Inside a housing with a supply port on one side, a cylindrical porous wall sorting cylinder with a large number of screening holes of different sizes in axial directions on the surrounding wall surface is installed, with the supply port side tilted high. It is installed rotatably, and hoppers are provided for different sizes of sorting holes along the lower end of this porous wall sorting tube and the porous wall sorting tube, and piping is drawn out from these hoppers to the outside of the housing. Characteristic particle sorting equipment. (2) The granular material sorting device according to claim 1, wherein the cylindrical porous wall sorting cylinder has sorting holes formed in the wall surface that gradually increase in size from the supply port side. (3) The cylindrical porous-walled sorting tube is divided into a plurality of parts by an inner tube provided with a concentric and radial partition plate for powder grains according to claims 1 and 2. Body sorting device. (4) The particle sorting device according to claim 1, wherein each of the pipes drawn out from the hopper to the outside of the casing is provided with an on-off valve.