JP2001347189A - Straightly advancing feeder for supplying material to electrostatic separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a straightly advancing feeder for supplying material to an electrostatic separator which increases separation efficiency in the electrostatic separator by dispersing particulate supplied from a hopper as bloch in a width direction of the feeder and supplying the particulate with uniform height. SOLUTION: The straightly advancing feeder 1 for supplying the material to the electrostatic separator is provided with a first weir 11 at a first position in an advancing direction of the material from a supply port 21 of the hopper 20 for supplying the material to the straightly advancing feeder 1 and further a second weir 12 at a second position. The first weir 11 and the second weir 12 are composed of round bars and are provided in a direction vertical to the advancing direction of the material by being in close contact with a surface of a trough 10 over a whole region of width of the trough 10. Supplied material is a mixture of aluminum particulate and casting sand and a diameter of the second weir 12 is of the same degree as average grain size of the aluminum particulate being bigger among two.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear feeder for conveying powder or granules,
The present invention relates to a linear feeder for supplying a material to an electrostatic separator for supplying a mixture of a plurality of materials to the electrostatic separator.

[0002]

2. Description of the Related Art In a casting operation, a mold is made by embedding a wooden mold in a foundry sand and squeezing the mold, and a metal melted by heating is poured into the mold to be cooled and solidified. The cooled and solidified product is removed from the sand mold to remove the sand and cut and finished. Here, for example, when a sand mold is used as a core, it takes considerable time and effort to completely remove the attached sand. Therefore, in recent years, cutting is generally performed without completely dropping the sand. In this case, a mixture of metal cutting particles and molding sand is obtained as a chip. In recent years, there has been an increasing need for a recycling-type society, and there has been a demand for separating and reusing these mixtures which have been landfilled as slag waste.

[0003] Here, in order to reuse the metal sand, it is necessary that the separation between the metal particles and the molding sand is 100% reliable. If it can be completely separated, the metal particles can be used again as metal material and the foundry sand can be used again for sand molds,
This is because even a small amount of mixing will cause a defect in the product after reuse. Therefore, as a result of studying various methods as a separation method, it was determined that the use of an electrostatic separation device was preferable.

An outline of the electrostatic separation device will be described with reference to the drawings. FIG. 4 shows a schematic diagram of the electrostatic separation device 100.
The electrostatic separation device 100 is a device that separates a metal and a non-metal by utilizing the difference in the electric conductivity, and as shown in FIG.
1, the material to be sorted is supplied little by little from a straight-ahead feeder 200 (described later).

[0005] The material is charged with static electricity by the high voltage corona electric field by passing through the area of the corona electrode 102 and the electrostatic field electrode 103. After electrification, the good conductive material such as metal rapidly loses its charge due to the ground of the rotating drum 101 and thus loses its adhesive force due to static electricity. On the other hand, a defective conductive material such as a nonmetal retains a charge, and thus rotates while adhering to the surface of the rotating drum 101 by static electricity, and is scraped off by the rubber scraper 104. In FIG. 4, good conductors are represented by ●, and defective conductors are represented by Δ. As shown in FIG. 4, three containers are set at the separating and dropping positions, and a metal 105, a non-metal 106, and a non-sorted material 1
Collect 07. The metal 105 and the non-metal 106 are reused, and the non-fractionate 107 is separated again by the electrostatic separation device. By repeating this, it is completely separated.

Next, FIG. 5 is a schematic view showing an example of a conventionally used electromagnetic linear feeder 200. As shown in FIG. The straight feeder 200 conveys the granular material on the trough 201 from left to right in the figure by vibration. Coil 2
When the movable core 209 vibrates due to the electromagnetic force of the alternating current half-wave pulsating current flowing through the plate 07, the plate spring 208 and the trough 201 attached to one of the plate springs vibrate obliquely, and the granular material on the trough 201 is conveyed. You.

Here, from the configuration of the electrostatic separation device 100 described above, it is desirable that the material is supplied in a very thin state, more specifically, in a single layer at the stage of being supplied to the rotating drum 101. This is because when charged while being overlapped on the rotating drum 101,
This is because the chargeability of the superimposed particles is significantly reduced. In particular, when a defective conductive material is supplied in an overlapping manner on the good conductive material, the charged defective conductive material adheres to the good conductive material by an adhesive force due to static electricity, and is thus skipped from the rotating drum 101 together with the good conductive material. As a result, the defective conductive material is mixed in the container for collecting the good conductive material (the metal 105 in FIG. 4). In this case, the recovered metal 105 cannot be reused. In other words, such a stacking and supply to the rotating drum 101 leads to a decrease in separation performance, and makes recycling difficult.

Therefore, conventionally, the amount of material supplied to the rotating drum 101 is limited in accordance with the peripheral speed of the rotating drum 101 so that the material is not supplied in an overlapping manner. Since the supply amount to the rotary drum 101 is the same as the supply amount to the linear feeder 200, the supply amount is limited by reducing the outlet of the hopper that supplies the material to the linear feeder 200. Here, the material to be separated is a mixture of molding sand, which is a powder and a poor conductor, and aluminum cutting particles, which are a granule and a good conductor, and the diameter of the casting sand is 100 to 300 μm and the diameter of the aluminum cutting particles is 100 to 300 μm. Is 1 to 2 mm, and if the height of the outlet of the hopper is 10 mm or less, clogging may occur. For this reason, the height of the outlet of the hopper is secured so that clogging does not occur, and the supply amount is limited by changing the width of the outlet.

[0009]

However, in the above-described conventional method, the width of the hopper outlet is reduced.
The supply material cannot be supplied to the entire width of the trough 201 of the linear feeder 200. Since the straight feeder 200 conveys the material in the traveling direction by oblique vibration, the material spreads in the width direction by vibration alone during conveyance, but is completely spread due to the limitation of the length of the trough 201. Before being supplied to the rotating drum 101.

For example, FIG. 6 shows a top view of the straight feeder 200, and FIGS. 7 to 9 show sectional views of the state of the material 300 at each transfer position. 7 to 9 respectively show A in FIG.
-A section, BB section, and CC section are shown. As shown in FIGS. 6 to 9, the material 300 gradually spreads in the width direction centering on the hopper supply port 211, but still has a somewhat semi-cylindrical shape near the outlet of the trough 201 (position C). Was supplied to the device 100. Therefore, the material 300 overlaps at the center and the rotating drum 1
01, there is a possibility that the charging may be incomplete as described above, and a separation failure may occur, in which the molding sand is mixed with the aluminum cutting particles. That is,
Since the casting sand is mixed with the metal 105, it is not completely separated by repeating the separation, and there is a problem that the recycling becomes difficult.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to disperse powders solidified and supplied from a hopper in the width direction of a feeder and supply the same at a uniform height. Accordingly, it is an object of the present invention to provide a feeder for feeding a material to an electrostatic separation device that increases the separation efficiency of the electrostatic separation device.

[0012]

In order to achieve the above object, according to the first aspect of the present invention, a material, which is a mixture of a plurality of kinds of materials consisting of powder or granules, is supplied to a rotating drum and charged. A linear feeder for supplying a material to an electrostatic separation device that separates by utilizing the fact that the adhesive force to the rotating drum is different depending on the conductivity of the material, wherein the supply of the material to the linear feeder is performed by the linear feeder. In a straight-ahead feeder that is performed only in a part of the width, one or more weirs having a constant height perpendicular to the traveling direction are provided on the straight-ahead feeder over its entire width.

According to the configuration of the present invention, the material supplied to a part of the linear feeder collides with the weir by being conveyed by the linear feeder. This causes a portion of the material to be stopped at the weir and another portion to change lateral movement in the advancing direction. A lot of material is stopped at a portion of the weir where a large amount of material collides, and the material is stacked in front of the weir. After this, the material further conveyed advances by climbing over the mountain, and when climbing over, the mountain collapses and the material spreads right and left. The material supplied to one portion is dispersed in the width direction by repeating the above process for the material conveyed one after another. Here, if an electromagnetic linear feeder is used as the linear feeder, the material is conveyed by being subjected to vibration, so that the peaked portion is easily broken and dispersed in the width direction. In particular, for a mixture having different particle diameters, there is an effect of moving small particles to both sides. As a result, the material supplied to a part of the rectilinear feeder is supplied to the electrostatic separation device at a uniform height regardless of the position in the width direction.

According to a second aspect of the present invention, there is provided a linear feeder for supplying a material to an electrostatic separator according to the first aspect, wherein the material is a mixture of aluminum particles and molding sand. Wherein two or more weirs are provided, and the height of the last weir is substantially the average particle size of the aluminum particles.

According to the structure of the invention described above, since the materials are aluminum particles and foundry sand, the aluminum particles have a larger particle size, and the height of the last weir has a larger particle size. The average particle size of the aluminum particles is approximately the same. For this reason, a large number of aluminum particles are temporarily stopped at the last weir, and the foundry sand that has been piled thereon easily crosses the weir without being stopped. Further, the aluminum particles also get over the weir by being vibrated by the linear feeder. That is,
This weir separates the aluminum particles from the foundry sand piled thereon. Therefore, the aluminum particles and the molding sand are separated from each other without overlapping each other and supplied to the electrostatic separation device.

According to a third aspect of the present invention, there is provided a linear feeder for supplying a material to an electrostatic separation device according to the first or second aspect of the present invention. The average stacking height is smaller than the minimum particle size of the aluminum particles.

According to the configuration of the present invention, at least the aluminum particles and other materials are not stacked at the outlet of the straight feeder. Therefore, when the material is supplied from the linear feeder to the rotating drum of the electrostatic separation device, the aluminum particles and the molding sand are not charged on the rotating drum in a state where they overlap with each other. As a result, there is no risk of occurrence of poor separation such that the charged molding sand adheres to the aluminum particles and is collected together in the metal collection container. Further, there is no possibility that the aluminum particles are stacked and supplied. Since the aluminum particles are not charged and adhere to the rotating drum, the molding sand collected in the non-metal recovery container does not include the aluminum particles and can be reused as the molding sand. There is a possibility that the molding sands are supplied in a stacked manner, but in this case, the molding sand that has risen is also charged, though weakly, so that it tends to adhere to the rotating drum via the molding sand below. Therefore, the particles are not scattered at least like aluminum particles but are collected in an intermediate non-separated material collection container. In other words, the aluminum particles recovered in the metal recovery container do not contain casting sand, and can be used again as an aluminum raw material. Further, the material collected in the intermediate non-separated material collection container is supplied to the electrostatic separation device again and separated.
Separation efficiency can be adjusted by changing the size of the non-separated material collection container, and both the metal collection container and the non-metal collection container can be reused at 100% without any poor separation. By repeatedly separating the unseparated material together with the newly generated material, the separated material can be surely separated and recycled, so that the cost for landfill disposal as waste, which has been conventionally required, is not required.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a feeder for feeding a material to an electrostatic separator according to an embodiment of the present invention. FIG. 1 is a top view of the rectilinear feeder according to the present embodiment, and FIG. 2 is a side view of the rectilinear feeder. Here, the structure of a portion related to the driving of the straight-ahead feeder 1 (a portion formed below the trough 10) is the same as the conventional one, and the description will be given with the same reference numerals.

As shown in FIGS. 1 and 2, two weirs (a first weir 11 and a second weir 12) are provided on the trough 10 of the straight feeder 1 at right angles to the traveling direction of the material 30 and over the entire width thereof.
Is provided. The first weir 11 is 3 mmφ, the second weir 12
Are 1.5 mmφ both round rods, the supply port 21 of the hopper 20 for supplying the material 30 onto the trough 10 and the first weir 1
The distance between the first weir 11 and the second weir 12 is also 70 mm. The first weir 11 and the second weir 12 are both fixed to the surface of the trough 10 by welding or screwing, and vibrate integrally with the trough 10.

Here, the material 3 supplied from the hopper 20
0 is a mixture of aluminum cutting particles and foundry sand. Each particle size is about 1 to 2 mm of aluminum particles, casting sand 10
0-300 μm, about 40% aluminum, about 60% sand
% Mixed. Since the height of the supply port 21 of the hopper 20 needs to be 10 mm or more so as not to cause clogging due to the aluminum particles, the width of the supply port 21 is limited to 15 to 30 mm in order to limit the supply amount of the material 30. Have been. Since the supply port 21 is provided at the center of the trough 10 in the width direction, the material 30 immediately after being supplied onto the trough 10 from the hopper 20 is solidified at the center with respect to the width of the trough 10. I have. The second weir 12 of the straight feeder 1
Is 1.5 mmφ, so that the material 30 is formed so as to have substantially the same particle size as the aluminum particle having the larger particle size.

Next, a portion related to driving of the linear feeder 1 will be described. As shown in FIG. 2, the straight feeder 1 conveys the powdery material on the trough 10 from the left to the right in the figure while vibrating the granular material on the trough 10 with an electromagnetic vibration feeder. It comprises a movable part 203 and a vibration-proof spring 204. The driving section provided in the fixed section 202 has a movable core 209 fixed to one end of a leaf spring 208 corresponding to the fixed core 206 and the coil 207 fixed to the fixed frame 205. . Since the other end of the leaf spring 208 is fixed to the fixed frame 205, the movable core 209 vibrates due to the electromagnetic force of the AC half-wave pulsating current flowing through the coil 207, and the vibration
8 resonates.

Further, the movable core 209 is fixed to the movable frame 210 in the movable portion 203,
Is fixed to the trough 10, the vibration of the movable core 209 causes the trough 10 to vibrate via the movable frame 210. As shown in FIG. 2, the fixed core 206 and the coil 2
07 is fixed at a fixed angle to the horizontal, the vibration of the movable core 209 is oblique to the horizontal plane, and the vibration of the trough 10 is oblique to the upper surface of the trough 10. Will do. Thus, the material 30 on the trough 10 is vibrated obliquely, and is conveyed while being fluttered from the surface of the trough 10 in the traveling direction by the vibration. The whole of the straight feeder 1 is supported by the vibration-proof spring 204 and is vibration-proof.

Next, the configuration of the electrostatic separation device 100 to which the material 30 is supplied by the linear feeder 1 will be described with reference to the schematic diagram of FIG. The electrostatic separation device 100 is a device that separates a metal and a non-metal by utilizing the difference in the electrical conductivity as in the related art, and as shown in FIG.
A rotating drum 101 which rotates at 0 rpm and is grounded is provided. Material 3 to be sorted from straight feeder 1
Zero is supplied little by little onto the rotating drum 101, and passes through the range of the corona electrode 102 and the electrostatic field electrode 103 to charge static electricity by the high voltage corona electric field.

After charging, the aluminum particles, which are a good conductive material, rapidly lose their charge due to the grounding of the rotating drum 101, and thus lose their adhesion due to static electricity.
The rotating drum 101 is blown off by the centrifugal force generated by one rotation. On the other hand, the molding sand, which is a defective conductive material, retains the electric charge, and thus rotates while being attached to the surface of the rotating drum 101 by the electrostatic force, and is scraped off by the rubber scraper 104. In FIG. 4, aluminum particles are marked with ● and foundry sand is marked with ▲.
It is represented by As shown in FIG. 4, the aluminum particle collection container 105 and the foundry sand collection container 10
6. The non-separated material collection container 107 is set and collected. The aluminum particles and the foundry sand are reused, respectively, and the unfractionated material is separated again with the material 30 by the electrostatic separation device 100. By repeating this, the non-fractionated substances gradually decrease and are completely separated.

Next, the result of transporting the material 30 supplied from the hopper 20 using the straight feeder 1 is shown in FIG. 3 as the pile height of the material 30 at each position on the trough 10. In FIG. 3, in each square frame, the result of measuring the stacking height of the material 30 at the position indicated by the arrow using a caliper is shown in units of mm.

As shown in FIG. 3, the supply port 2 of the hopper 20
The material 30 supplied at a height of 1 to 10 mm or more is averaged to about half the height at the center between the first weir 11 and the second weir 12, and further after the second weir 12, the height of the first weir 12 is further reduced.
// 3. In other words, it indicates that it is spreading in the width direction, and in the vicinity of the exit of the trough 10, the height at each position is substantially uniform. Here, since the diameter of the second weir 12 is substantially the same as the particle diameter of the aluminum granules, considerable averaging is performed after the second weir 12, and the average height near the outlet of the trough 10 is smaller than that of the aluminum granules. It can be seen that the particle size is smaller than the body particle size. Therefore, at least the aluminum particles are prevented from being supplied overlapping with the other particles.

As described in detail above, according to this embodiment, the first weir 1 is placed on the trough 10 of the linear feeder 1.
1 and the second weir 12, the supply port 21 of the hopper 20 is provided.
Material 30 supplied to a part of the width direction from the first weir 11
And it collides with the 2nd weir 12, and is expanded in the horizontal direction. Therefore, the material 3 solidified and supplied from the hopper 20
By transporting the “0” by the straight feeder 1, it can be distributed to the width direction of the trough 10 so as to be uniform and supplied to the electrostatic separation device 100. Since the supply amount of the material 30 is limited by the size of the supply port 21 of the hopper 20, the material 30 having a desired thickness can be formed at any position in the width direction by making the material 30 uniform in the width direction of the trough 10. It can be supplied to the separation device 100. Thereby, the separation efficiency in the electrostatic separation device 100 can be increased.

Further, since the diameter of the second weir 12 is 1.5 mmφ, which is the average particle diameter of the aluminum granules, a large number of aluminum granules are temporarily stopped by the second weir 12.
On the other hand, the foundry sand accumulated on the aluminum particles easily passes over the second weir 12. Therefore, by providing the second weir 12, it is possible to prevent the aluminum particles and the casting sand from being stacked and conveyed. As a result, there is no possibility that the charged molding sand adheres to the aluminum granules and is collected in the aluminum granule collecting container 105, and other materials are mixed in the aluminum granule collecting container 105 and the casting sand collecting container 106. Because there is no, you can reuse each. Therefore, 100% of the aluminum particles and the molding sand can be separated by repeatedly separating the non-fractionated material several times, so that it can be completely recycled by reusing each. Also, the trough 1 of the linear feeder 1
There is no need to change the length of 0, etc., and it can be easily implemented with only a slight modification from the conventional one.

It should be noted that the present invention is not limited to the above-described embodiment, and can be implemented with the following modifications without departing from the spirit of the invention. For example, numerical values such as the number, shape, thickness, and arrangement of the weirs are merely examples, and can be changed as appropriate. For example, the number of weirs can be increased to further shorten the trough 10. Further, for example, the shape of the weir is a round bar in the above-described embodiment, but it may be implemented using a square bar or a triangular bar. Also, for example, the thickness of the weir is determined by the material 30 supplied.
It may be changed according to the average particle size of each material.

[0030]

According to the first aspect of the present invention,
The material supplied to the straight feeder collides with the weir and is dispersed in the width direction, so that the pile height is made uniform. This allows
The material supplied to a part of the linear feeder is dispersed at a uniform height in the width direction and supplied to the rotating drum of the electrostatic separation device, so that the separation efficiency in the electrostatic separation device is increased.

According to the construction of the second aspect of the present invention, since the last weir has substantially the average particle size of the aluminum granule which is the larger of the materials, the aluminum granules overlap with other materials. And is not supplied to the electrostatic separation device. Therefore, the separation efficiency in the electrostatic separation device is further increased.

According to the third aspect of the invention, since the material is supplied with the average pile height being smaller than the particle size of the aluminum particles, the material becomes one layer on the rotating drum, and the metal is recovered. There is no separation failure such as non-metal contamination in the container or metal contamination in the non-metal recovery container. Therefore, the separation can be reliably performed by repeating the separation of the non-separable substances several times. As a result, all the materials can be separated and reused, and recycling becomes possible.

[Brief description of the drawings]

FIG. 1 is a top view showing a linear feeder for supplying a material to an electrostatic separation device.

FIG. 2 is a side view showing the straight feeder.

FIG. 3 is an explanatory view showing the height of a material conveyed by a straight feeder.

FIG. 4 is an explanatory view showing the structure of the electrostatic separation device.

FIG. 5 is an explanatory view showing the structure of a conventional straight-ahead feeder.

FIG. 6 is an explanatory view showing an arrangement of materials conveyed by a conventional straight feeder.

FIG. 7 is a cross-sectional view showing an arrangement of materials conveyed by a conventional straight feeder.

FIG. 8 is a cross-sectional view showing an arrangement of materials conveyed by a conventional straight feeder.

FIG. 9 is a cross-sectional view showing an arrangement of materials conveyed by a conventional straight feeder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Straight feeder 10 Trough 11 First weir 12 Second weir 20 Hopper 30 Material 100 Electrostatic separation device 101 Rotary drum

Claims (3)

[Claims] 1. A method in which a material, which is a mixture of a plurality of kinds of materials consisting of powder or granules, is supplied to a rotating drum and charged, and a method is used by utilizing the fact that the adhesive force to the rotating drum varies depending on the conductivity of the material. A linear feeder for supplying the material to an electrostatic separation device to be separated, wherein the supply of the material to the linear feeder is performed only for a part of the width of the linear feeder; A linear feeder for supplying a material to an electrostatic separation device, wherein one or more weirs having a constant height perpendicular to the traveling direction are provided over the entire width thereof. 2. The linear feeder for feeding a material to an electrostatic separation device according to claim 1, wherein the material is a mixture of aluminum granules and molding sand, and wherein at least two weirs are provided. Wherein the height of the weir is substantially equal to the average particle size of the aluminum particles. 3. The linear feeder for supplying a material to an electrostatic separation device according to claim 1 or 2, wherein an average stack height of the material at an outlet of the linear feeder is a minimum particle size of the aluminum particles. A linear feeder for supplying a material to an electrostatic separation device, wherein the feeder is configured to be smaller.