JPH0929136A - Solid-liquid separation and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize equipment and to reduce treating time. SOLUTION: A slurry stored in a tank 10 of a metal pulverizing means 30 is forcibly fed to a 1st hydrocyclone 32 with a slurry pump 34. A coarse powder forming under flow and discharged from a bottom outlet 32a of the hydrocyclone 32 is recovered in a recovering vessel 36. The slurry overflowing from the upper outlet 32c of the 1st hydrocyclone 32 after the coarse powder is separated is fed to a 2nd hydrocyclone 38. The metal powder of the product forming under flow and discharged from the bottom outlet 38b of the 2nd hydrocyclone 38 is dehydrated by a dehydrating device 42 and dried by a drying device 46.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-liquid separation method and apparatus for separating powder having a required particle size from a slurry in which powder produced by a liquid atomizing method is turbid in a liquid. .

[0002]

2. Description of the Related Art The powder metallurgy method obtains a solid metal by sintering, injection molding or HIP of powder metal. The powder metal used in the method has a uniform powder property and high quality.
Moreover, since it is required that it can be manufactured economically,
Generally, a gas or liquid (water) spraying method (atomizing method) is used. In particular, a high pressure (40 to 100 MPa) water atomization method is used to obtain a powder having an average particle size of 50 μm or less.

The outline of this atomizing method will be described with reference to FIG. 5. The metal melted in an electric furnace (not shown) is a tundish 1 provided on the top of a cylindrical tank 10.
2 and is blown into the tank 10 through the pouring nozzle 14. A ring-shaped water injection nozzle 16 is provided in the vicinity of the pouring nozzle 14, and the water blown at high pressure from this collides with the molten metal in the tank 10 to atomize it. The atomized molten metal falls into the water stored in the tank 10 and rapidly solidifies,
It becomes a powder metal (solid particles) of several μm to several 100 μm.

From the slurry in which the water and the powder metal accumulated on the bottom of the tank 10 are turbid, the powder metal is separated from the water through the following steps, and the powder metal having a desired particle size is recovered. That is, the slurry is a slurry pump 1 connected to the lower part of the tank 10 as shown in FIG.
It is supplied to the recovery device 20 having a large capacity like a water tank via 8. In this recovery device 20, the powder metal is allowed to settle spontaneously, it is confirmed that the powder metal and water are separated, and a drain valve (not shown) is opened to release water (supernatant), and then the main valve. The powder metal is recovered by opening (not shown). Then, this powder metal is dehydrated by the dehydrator
And forcibly removing residual moisture through a filter provided at the bottom of the device by pressurizing it with high-pressure air, and then supplying the powder metal to the drying device 24 for drying. Then, the dried powder metal is supplied to the classifying device 26, where it is classified by a net, an air stream, or the like to recover the powder metal having a desired particle size.

[0005]

As described above, since the natural sedimentation method was conventionally used to separate water and powder metal from the slurry, the finer the powder metal, the more time it takes to separate it. There was a problem that production capacity was not improved. Further, since the natural sedimentation type recovery device 20 is a batch process, when a large amount of water is used to produce a large amount of powder metal by the atomization method, a large volume of recovery that can store a large amount of slurry at one time is collected. It is pointed out that the device 20 must be installed, the facility becomes large, a large installation space is required, and the installation cost increases. Further, since it takes a long time for sedimentation, there is a problem that production efficiency is reduced.

Further, when the powder metal recovered in the previous batch is different from the powder metal recovered in the next batch, in order to prevent contamination by contamination of different metals, each type of metal is different. First, it is necessary to completely remove the powder metal adhering to the inner surface of the recovery device 20. That is, if the size of the recovery device 20 becomes large in order to process a large amount of slurry, it takes a long time to clean the device 20 and the productivity is lowered.

Furthermore, in classification, in order to obtain a powder product having a relatively fine particle diameter, a finer particle size of several μm
Although it is necessary to classify the level of powder, it is not possible to classify it with a classifier using a net, and it is necessary to further classify it with an air flow, which causes a problem of increasing the number of processes.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems inherent in the above-mentioned prior art, and has been proposed to suitably solve the problems. It is an object of the present invention to provide a solid-liquid separation method and device to be obtained.

[0009]

[Means for solving the problems] To overcome the above-mentioned problems,
In order to achieve the intended purpose, the solid-liquid separation method according to the present invention is a method in which a slurry in which solid particles are turbid in a liquid is continuously supplied to at least two hydrocyclones, and the required particle size is obtained by the cyclones. It is characterized in that the solid particles of are separated.

Further, in order to suitably carry out the above-mentioned method,
A solid-liquid separation device according to another invention of the present application is a slurry pump connected to a tank for storing a slurry in which solid particles are turbid in a liquid, and the slurry pump is connected and pumped by the pump. A first hydrocyclone for separating solid particles of a required particle size from the slurry, and a second hydrocyclone connected to the first hydrocyclone for separating solid particles of a required particle size from the slurry overflowed from the cyclone. Is characterized by.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the solid-liquid separation method according to the present invention will be described below with reference to the accompanying drawings in relation to an apparatus capable of suitably carrying out the method. In addition, the solid-liquid separation method of the present invention, as described in Examples below,
It is preferably used for separating powder metal produced by the liquid atomizing method from water and the like.

[0012]

[First Embodiment] FIG. 1 shows the overall configuration of a solid-liquid separation device according to the first embodiment, in which the pouring nozzle 14 and the ring-shaped pouring nozzle 16 as described above with reference to FIG. The first hydrocyclone 32 is arranged adjacent to the metal powderizing means 30 including the atomizer 28 and the tank 10. A slurry pump 34 communicating with the lower portion of the tank 10 is connected to the inlet 32a of the first hydrocyclone 32 so that the slurry, which is a mixture of powder metal and water produced by the metal powderizing means 30, is The pressure is fed to the first hydrocyclone 32 via the slurry pump 34.
Below the first hydrocyclone 32, a recovery container 36 for recovering coarse powder that is underflowed from the lower outlet 32b of the cyclone 32 is arranged. In addition,
The first hydrocyclone 32 is set so that only coarse powder having a large particle size outside the desired particle size range (area indicated by A in FIG. 2) is separated.

At the upper outlet 32c of the first hydrocyclone 32, the inlet 38 of the second hydrocyclone 38 is provided.
a is communicatively connected via the connecting pipe 40, the coarse powder is separated by the first hydrocyclone 32, and the slurry overflowing from the upper outlet 32c is connected via the connecting pipe 40 to the second
It is configured to be supplied to the hydrocyclone 38.
The lower outlet 38b of the second hydrocyclone 38 is connected to, for example, a decanter type dehydrator 42 so that the powder metal separated by the cyclone 38 and underflowing from the lower outlet 38b can be continuously dehydrated. Has become. In the second hydrocyclone 38, the powder metal (product) having the grain size in the region indicated by C in FIG.
It is set to underflow from b. Also,
The upper outlet 38c of the second hydrocyclone 38 communicates with the discharge container 44, and is configured to discharge the fine powder with a small particle size (area indicated by B in FIG. 2) that overflows from the upper outlet 38c.

A rotary kiln type drying device 46, for example, is connected to the dehydrating device 42 so that the powder metal dehydrated by the dehydrating device 42 can be continuously dried and taken out as a product.

[0015]

[Operation of First Embodiment] Next, the operation of the solid-liquid separation device according to the first embodiment will be described in relation to the solid-liquid separation method.

The slurry stored in the tank 10 of the metal powderizing means 30 is pressure-fed to the first hydrocyclone 32 via the slurry pump 34. In this cyclone 32, the nonstandard powder contained in the slurry is separated and underflowed from the lower outlet 32b to be collected in the recovery container 36, and the slurry from which the coarse powder is separated overflows from the upper outlet 32c. Connection pipe 40
And is supplied to the second hydrocyclone 38 via. The coarse powder recovered in the recovery container 36 is reclassified into powder metal having a required particle size contained in the coarse powder for use as a product, or melted again for reuse.

In the second hydrocyclone 38, powder metal having a desired particle size, which is a product contained in the slurry, is separated and underflowed from the lower outlet 38b, and is supplied to the dehydrator 42. Further, the water contained in the slurry and the non-standard fine powder overflow from the upper outlet 38c and are discharged into the discharge container 44. Also for this fine powder, the powder metal having a required particle size contained in the fine powder is classified and used as a product, or is melted again and reused. Then, the powder metal supplied to the dehydrating device 42 is forcibly removed of the water remaining therein, and further supplied to the drying device 46 to be dried. As a result, powder metal having a desired particle size is recovered.

That is, two hydrocyclones 3
Since the powder metal is separated from the slurry by 2, 38 and is classified into a desired particle size, it is not necessary to classify after passing through the drying device 46, and the number of steps can be reduced. Further, since the slurry can be continuously processed by the hydrocyclone 32, 38, the processing time can be shortened. Moreover, since continuous treatment is possible, a large amount of slurry can be treated without increasing the size of the cyclones 32, 38, which can reduce equipment costs and save space.

[0019]

[Second Embodiment] FIG. 3 shows the entire configuration of a solid-liquid separation device according to a second embodiment, in which the slurry stored in the tank 10 of the metal powderizing means 30 is first
The first hydrocyclone 3 via the slurry pump 48
2 is configured to be pumped. The coarse powder separated by the first hydrocyclone 32 and flowing out as an underflow from the lower outlet 32 a is collected in the first collecting container 50. The upper outlet 32c of the first hydrocyclone 32 is communicatively connected to the intermediate tank 52, and the slurry overflowing from the upper outlet 32c is stored in the intermediate tank 5
2 is configured to be temporarily stored. Also intermediate tank 5
The second slurry pump 54, which is communicatively connected to the lower part of 2, is communicatively connected to the inflow port 38 a of the second hydrocyclone 38. That is, the supply rate of the slurry to the second hydrocyclone 38 is adjusted by the second slurry pump 54 so that the powder metal can be reliably separated in the cyclone 38.

A second recovery container 56 is disposed at the lower outlet 38b of the second hydrocyclone 38, and the lower outlet 3
It is configured to collect the powder metal having a particle size that becomes an underflowed product from 8b in the recovery container 56. The powder metal recovered in the second recovery container 56 is taken out as a product after passing through the dehydrator 42 and the dryer 46.

[0021]

[Operation of the Second Embodiment] In the second embodiment, the slurry stored in the tank 10 of the metal powderizing means 30 is pressure-fed to the first hydrocyclone 32 via the first slurry pump 48. . In the first hydrocyclone 32, the non-standard coarse powder is separated and underflows from the lower outlet 32b to be collected in the first recovery container 50, and the slurry from which the coarse powder is separated overflows from the upper outlet 32c. And is supplied to the intermediate tank 52. The slurry stored in the intermediate tank 52 is the second slurry pump 54.
Is fed under pressure to the second hydrocyclone 38, and the non-standard fine powder is separated and discharged from the upper outlet 38c by the cyclone 38, and the powder metal having a desired particle size to be a product underflows from the lower outlet 38b. 2 Collected in the collection container 56.

When the required amount of powder metal is stored in the second recovery container 56, the powder metal in the container 56 is removed from the dehydrator 4.
2 to remove residual water, and then supply to the drying device 46 for drying. As a result, powder metal having a desired particle size is recovered.

That is, also in the second embodiment, the separation and classification of the powder metal from the slurry can be performed in a short time, and the productivity can be improved. Also, the first
The slurry is fed under pressure to the hydrocyclone 32 and the second hydrocyclone 38 by the corresponding slurry pump 4
Since it is carried out via 8, 54, the separation and classification of the powder metal in each cyclone 32, 38 can be reliably carried out.

[0024]

[Modification] FIG. 4 shows a modification of the second hydrocyclone 38 shown in the second embodiment.
It is configured by radially arranging (for example, 6) small hydrocyclones 58, and a branch cylinder 60 communicating with and connected to the second slurry pump 54 is arranged in the center thereof. The branch pipe 60 is provided with a connecting pipe 62 which is connected to the inlet of each small hydrocyclone 58.
The slurry pressure-fed from the second chiller pump 54 to the branch cylinder 60 is supplied to each small hydrocyclone 58 through each connecting pipe 62, and the powder metal as a product is separated.

Also, a plurality of small hydrocyclones 58
A hopper 64 is disposed below the above, and collects powder metal, which is an underflowed product, from the lower outlet of each cyclone 58 and collects it in the second recovery container 56. In addition, the fine powder separated by each small hydrocyclone 58
After being collected in the stacking cylinder 66, it is discharged into the discharge container 44.

In the examples, the case where the separation of water and the classification of powder metal are performed by two hydrocyclones has been described, but the present invention is not limited to this.
Three or more hydrocyclones may be used to recover the powder metal of the desired particle size. Further, as the dehydrator, a filter type can be adopted, and as the dryer, a vacuum method, a centrifugal separation method or the like can be adopted. Further, the powder to be separated / classified is not limited to metal, but may be ceramics or the like, and can also be adopted for separating water and solid particles from sludge.

[0027]

As described above, according to the solid-liquid separation method and apparatus of the present invention, the powder metal is separated from the slurry by a plurality of hydrocyclones and the particles are classified into a desired particle size. Classification can be omitted and the number of steps can be reduced. Moreover, since the slurry can be continuously treated by the hydrocyclone, the treatment time can be shortened. In addition, even if the particle size of the powder to be the product becomes fine, it is possible to reliably and continuously classify the powder, and it becomes possible to easily control the particle size level for each powder product. Further, since continuous processing is possible, a large amount of slurry can be processed without increasing the size of the cyclone, and equipment cost and installation area can be saved. Further, since the cyclone has a simple structure and can be downsized, cleaning can be easily performed in a short time and contamination by powders of different types can be prevented.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a solid-liquid separation device according to a first embodiment.

FIG. 2 is a particle size distribution diagram of powders classified by a solid-liquid separator.

FIG. 3 is a schematic configuration diagram of a solid-liquid separation device according to a second embodiment.

FIG. 4 is a schematic configuration diagram showing a modified example of the second hydrocyclone of the solid-liquid separation device according to the second embodiment.

FIG. 5 is a schematic configuration diagram of a solid-liquid separation device according to a conventional technique.

[Explanation of symbols]

 10 Cylindrical Tank 32 First Hydrocyclone 34 Slurry Pump 38 Second Hydrocyclone 42 Dehydrator 46 Dryer 48 First Slurry Pump 54 Second Slurry Pump

Claims (4)

[Claims] 1. A slurry in which solid particles are turbid in a liquid is continuously supplied to at least two hydrocyclones (32, 38), and the cyclones (32, 38) produce solid particles having a required particle size. A solid-liquid separation method characterized in that separation is performed. 2. A slurry pump (34, 48) connected to a tank (10) for storing a slurry in which solid particles are turbid in a liquid, the slurry pump (34, 48) being connected, The pump (34,4
8) A first hydrocyclone (32) for separating solid particles of a required particle size from the slurry pumped by 8), and a first hydrocyclone (32) connected to the slurry, which is overflowed from the cyclone (32) and has a required particle size. A solid-liquid separation device comprising a second hydrocyclone (38) for separating solid particles. 3. The first hydrocyclone (32) and second
A slurry pump (54) is inserted between the hydrocyclone (38) and the slurry pump (54) is configured to pump the slurry overflowing from the first hydrocyclone (32) to the second hydrocyclone (38). Claim 2
The solid-liquid separation device as described in the above. 4. A dehydrator (42), to which solid particles underflowed from the cyclone (38) are supplied, is connected to the second hydrocyclone (38), and the dehydrator (4) is connected.
The solid-liquid separator according to claim 2 or 3, wherein a drying device (46) is connected to 2).