JPH09113147A - Method and device for screening of powdery/granular material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To drastically improve the classifying efficiency of every kind of powdery/granular material, and effectively utilize a space in a factory by providing a compact structure, and minimizing the installation space, and at the same time, reduce the equipment cost. SOLUTION: A material consisting of a powdery/granular body which is fed by dropping on an entrance chute 13, is screened into a fine granular material and a coarse granular material by a gap of a bar screen 15 which is provided on the extended line under the entrance chute 13 for a screening method of powdery/granular material. For such a screening method, on a sliding surface 13a of the entrance chute 13, at least one slide obstacle 16 is provided, and on the top of the slide obstacle 16, a tilted surface with an angle of repose of the material in response to the material, is formed. Then, the material is segregated into a fine granular material and a coarse granular material by using the tilted surface. Then, the material is transferred onto the bar screen 15 and a screening is performed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to powders having different particle sizes.
The present invention relates to a method and an apparatus for sieving powders / granulates that can effectively classify the granules by a combination of an approach chute and a bar screen.

[0002]

2. Description of the Related Art Conventionally, in order to improve the air permeability and combustion efficiency of a sintering raw material layer in a sintering machine, the sintering raw material is coarse grained material and fine grained raw material before the sintering raw material is charged into the sintering machine. A slit chute type classification device composed of a combination of an approaching chute and a bar screen is used for sieving into the following, and as a specific example thereof, a slit chute type classification device described in JP-A-1-104725. There is a device. FIG. 11 conceptually shows the configuration of this slit chute type classifying device C. As shown in the drawing, the slit chute type classifying device C includes an approach chute 100 arranged in an inclined state below a hopper (not shown), and the approach chute 10
It is arranged on the downward extension line of 0 and is constituted by a bar screen 102 composed of a plurality of linear members 101. Also, below the bar screen 102 is a pallet 1
03 is arranged so that it can run freely. In addition, in the above-described configuration, the interval between the linear members 101 is set to gradually widen downward. The classification work (screening work) by the slit chute type classifying device C having such a configuration will be briefly described with reference to FIG. 11. The sintering material a dropped and supplied from the hopper onto the approaching chute 100 via the feeder slides down on the approaching chute 100. Since a bar screen 102 in which a plurality of linear members 101 having the same diameter are tensioned in the width direction is provided on the extension line of the run-up chute 100, the sintering raw material a that inclines down slides next to the bar screen 102. Sliding down the upper surface, first, the fine raw material b in the sintering raw material a is classified and dropped on the upper end 104 side, and the fine grain raw material c is sequentially classified and dropped as it slides down to the lower end 105 side. . On the other hand, the remaining coarse-grain raw material d that has slid down on the bar screen 102 without passing through the bar screen 102 remains as it is at the lower end portion 1 of the bar screen 102.
It will fall from 05. Then, of the sintering raw materials a classified in this way, the coarse-grain raw material d is first charged into the lower layer portion 106 of the traveling pallet 103, and then,
From the middle layer portion 107 to the uppermost portion 108, the fine grain raw material c and the fine raw material b are sequentially and continuously charged, and the pallet 1
The sintering raw material layer 109 will be formed in 03.

[0003]

However, the sieving work or classification work by the above-mentioned slit chute type classifying device C still has the following problems. That is,
Only by combining the approaching chute 100 and the bar screen 102, the classification efficiency could not be sufficiently improved. Specifically, in the actual sieving work, as shown in FIG. 12, the sintering raw material a that slides in layers on the single smooth sliding surface 110 of the approach chute 100 is:
Vertical grain size segregation is unlikely to occur, so that the sintering raw material a is transferred and sieved on the bar screen 102 with a small segregation. Therefore, the coarse grain raw material d was mixed in the sintering raw material under the sieve, and the sieving efficiency was poor.
In addition, in order to increase the classification efficiency, the bar screen 102
However, in this case as well, the classification efficiency cannot be improved as much as desired, and the slit chute type classifying device C becomes large in size, resulting in a large installation space and equipment cost. It will cost. The present invention has been made in view of such circumstances, including the above-mentioned sintering raw material,
The sieving efficiency or classification efficiency of all powders and granules can be remarkably improved, and it has a compact structure that minimizes the installation space and enables effective use of the factory space, as well as equipment costs. An object of the present invention is to provide a sieving device for reducing powder / granular substances.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The method for sieving the powder / granular material described above, a raw material consisting of the powder / granular material dropped and fed onto the run-up chute is passed through a gap of a bar screen provided on a downward extension line of the run-up chute to obtain a fine-grain raw material. In the method of sieving powder / granular material for sieving into a coarse-grained raw material, at least one sliding obstacle is provided on the sliding surface of the running chute, and the raw material is provided on the upper portion of the sliding obstacle according to the raw material. A slope having a repose angle of the raw material is formed, and the raw material is segregated into a fine-grain raw material and a coarse-grain raw material by using the slope, and then the raw material is transferred onto the bar screen for sieving. I have to. The method for sieving powder / granular material according to claim 2, wherein the raw material made of powder / granular material dropped and supplied onto the running chute is passed through a gap of a bar screen provided on a downward extension line of the running chute,
In the method of sieving a powder / granulate for sieving a fine-grain raw material and a coarse-grain raw material, at least one step portion is provided on the running chute, and the coarse-grain raw material in the raw material is provided in the step portion. The fine-grain raw material in the raw material is dropped near the step portion to be segregated while being dropped far from the step portion, and then the raw material is transferred to the bar screen for sieving. The powder / granular material sieving apparatus according to claim 3 has a runner chute disposed in an inclined state at a lower portion of a hopper, and a bar screen made of a plurality of linear members is provided on a downward extension line of the runner chute. In the sieving device for powders and granules, at least one sliding obstacle is arranged on the sliding surface of the approach chute.
Particularly, in the powder / granular material sieving apparatus according to claim 4, in the powder / granular material sieving apparatus according to claim 3, the sliding obstacle is projected in the width direction on the running surface of the approach chute. Formed from a long flat plate. The powder / granular material sieving apparatus according to claim 5 has an approaching chute arranged in an inclined state at a lower portion of a hopper, and a bar screen made of a plurality of linear members is provided on a downward extension line of the approaching chute. In the sieving device for powder and granules, at least one step is provided on the approach chute.

[0005]

According to the sieving method and apparatus for powders and granules according to claims 1, 3 and 4, when a raw material is dropped and supplied from the hopper onto the run-up chute, a long flat plate or the like having a certain height is provided. On the upstream side of the sliding obstacle consisting of, a slope having the angle of repose of the raw material is formed by the raw material itself. Of the raw materials, the coarse-grained raw material having a relatively small angle of repose rolls down on this slope at a high speed, and therefore falls to a position far from the sliding obstacle. On the other hand, of the raw materials, the fine-grained raw material has a large angle of repose, so that it rolls on the slope at a slow speed and falls in the immediate vicinity of a sliding obstacle. As a result, on the run-up chute just before the bar screen, since the raw material flows in a state in which the coarse-grain raw material is segregated in the upper layer portion and the fine-grain raw material is segregated in the lower layer portion,
Of the raw materials transferred to the bar screen, the fine-grain raw materials are preferentially sieved or classified. Further, in the powder and granular material sieving method and apparatus according to claims 2 and 5, when the raw material is dropped and supplied from the hopper onto the uppermost stage chute of the run-up chute having a step, the raw material is It slides on the sliding surface of the uppermost chute and falls onto the next chute. At this time, since there is a stepped portion between the uppermost chute and the next chute,
The coarse-grained material that easily rolls falls to a location far from the step on the sliding surface of the next-stage chute. On the other hand, the fine-grained raw material that is hard to roll falls to a place near the step. As a result, on the sliding surface of the next-stage chute, the raw material flows with the coarse-grained raw material segregated in the upper layer portion and the fine-grained raw material in the lower layer portion. Then, also in each subsequent stage chute, segregation between the coarse grain raw material and the fine grain raw material is similarly performed at each step portion. After the raw materials have been sufficiently segregated, the fine-grained raw materials among the raw materials that have come to the bar screen are preferentially sieved or classified.
In particular, when sieving a large amount of sintering raw material with a bar screen having a gap larger than the size of the undersize powder, the effect of the bar screen is more remarkable by classifying after segregating the upper layer to the lower layer. Can be expressed in

[0006]

In the method and apparatus for sieving powder / granular material according to claims 1, 3 and 4, a gliding obstacle is provided on the running chute and the gliding surface of the running chute is covered by the gliding obstacle. Since a slope having a repose angle of the raw material was formed and the slope segregated into the coarse grain raw material forming the upper layer portion and the fine grain raw material forming the lower layer portion, the raw material transferred to the bar screen was The fine-grain raw material can be preferentially sieved, and the coarse-grain raw material can be sieved, so that the sieving efficiency or classification efficiency of the powder / granulate can be remarkably enhanced. In the method and apparatus for sieving powder / granular material according to claims 2 and 5, at least one step is provided on the run-up chute, and at each step, the raw material is a coarse-grain raw material forming an upper layer and a lower layer. Since it is segregated with the fine-grain raw material that forms
Fine-grained raw material in the raw material that came to the bar screen can be preferentially sieved, and coarse-grained raw material can be sieved,
The sieving efficiency or classification efficiency of the granular material can be significantly increased. In addition, since the raw material can be pre-segregated into the coarse-grain raw material and the fine-grain raw material with the run-up chute, it is not necessary to increase the length of the bar screen, and the sieving device for the powder / granulate should have a compact structure. Since the device can be installed in the minimum installation space, it is possible to effectively use the space of a factory or the like and to manufacture the device at low cost.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention.

Here, FIG. 1 is an explanatory view of the conceptual overall structure of the powder / granular material sieving apparatus according to the first embodiment, and FIG.
Is an explanatory view of the sieving operation, FIG. 3 is a graph showing the relationship between the pitch or the distance from the bar screen between the sliding obstacles and the overall efficiency of the sieve, and FIG. 4 is the height of the sliding obstacle and the overall sieve efficiency. FIG. 5 is a graph showing a relationship between efficiency and efficiency, FIG. 5 is an explanatory view of a conceptual overall configuration of a powder / granular material sieving apparatus according to the second embodiment, and FIG. 7 is a graph showing the relationship between the chute angle of the run-up chute and the overall efficiency of the screen, FIG. 8 is a graph showing the relationship between the step of the run-up chute and the overall efficiency of the screen, and FIG. 9 is the number of steps of the run-up chute. FIG. 10 is a graph showing the relationship with the overall sieve efficiency, and FIG. 10 is a conceptual overall configuration explanatory diagram of the powder / granular material sieving apparatus according to the modification of the second embodiment.

As shown in FIG. 1, a hopper 11 having a sintering raw material 10 as an example of a raw material filled therein has a raw material cutting feeder 12 at a lower portion thereof. The powder / granular material sieving apparatus A according to the first embodiment is provided with the hopper 11
It is arranged below the
An approaching chute 13 arranged in an inclined state immediately below the hopper 11 and an extension line below the approaching chute 13
The bar screen 15 is composed of a plurality of linear members 14. Although not shown, a pallet is arranged below the bar screen 15 so that it can travel.

As shown in FIG. 1, the powder / granular material sieving apparatus A according to the first embodiment having the above-mentioned basic structure has a predetermined lengthwise direction on the sliding surface 13a of the approach chute 13. A feature is that two sliding obstacles 16 having a predetermined height are provided so as to be spaced apart from each other with a gap L. The sliding obstacle 16 may be at least one. Also,
In FIG. 1, the sliding obstacle 16 is formed by welding a long flat plate (flat bar) having a rectangular cross section extending in the width direction to the sliding surface 13a of the running chute 13, but the solid circular cross section has a long length. It can also be formed inexpensively and easily by welding a scale bar, a pipe having a hollow circular cross section, or the like to the running surface 13a of the approach chute 13.

Next, the sieving operation or classification operation of the sintering raw material 10 by the sieving apparatus A for powder / granular material having the above-mentioned structure will be described with reference to FIGS. 1 and 2. In FIG. 1, when the raw material cutting feeder 12 is operated, the sintering raw material 10 is dropped / supplied from the hopper 11 onto the running chute 13, and the sintering raw material 10 moves downward on the sliding surface 13 a of the running chute 13. Bar screen 15 located at
Downhill towards.

However, in the powder / granular material sieving apparatus A according to the first embodiment, as shown in FIG. 1, a predetermined pitch L is set in the longitudinal direction on the running surface 13a of the running chute 13.
Open, two sliding obstacles 16 having a predetermined height H
, The sintering raw material 10 first collides with the upper sliding obstacle 16. Then, the sintered raw material 10 collides with the sintered raw material 1 as shown in FIG.
When the upper slope 17 having a repose angle α of 0 is formed,
The coarse grain raw material 10a having a relatively small angle of repose is provided on the slope 17
It rolls on the upper side at a high speed, and falls to a portion below the sliding surface 13a between the sliding obstacles 16 and 16, that is, a portion far from the upper sliding obstacle 16. On the other hand, the fine-grained raw material 10b having a relatively large angle of repose rolls on the slope 17 at a slow speed and falls on the sliding surface 13a which is in the immediate vicinity of the upper sliding obstacle 16. As a result, the coarse-grain raw material 10a and the fine-grain raw material 10b in the sintering raw material 10 are
It will undergo the first segregation.

Next, the sintering raw material 10 collides with the sliding obstacle 16 in the lower stage. Then, when the lower slope 17 having the angle of repose α of the sintering raw material 10 is formed by the collision of the sintering raw material 10 as shown in FIG. Raw material 1
0a rolls on the slope 17 at a high speed, and falls to a position below the sliding surface 13a of the lower sliding obstacle 16, that is, a position far from the lower sliding obstacle 16. On the other hand, fine grain raw material 10b having a relatively large angle of repose
Will roll on the lower slope 17 at a slow speed and fall on the sliding surface 13a that is in the immediate vicinity of the lower sliding obstacle 16. As a result, the coarse grain raw material 1 in the sintering raw material 10
0a and the fine grain raw material 10b are subjected to the second segregation. As a result, on the run-up chute 13 immediately in front of the bar screen 15, the sintering raw material 10 flows to the bar screen 15 because the coarse-grain raw material 10a flows in the upper layer and the fine-grain raw material 10b segregates in the lower layer. In the sintering raw material 10, the fine-grain raw material 10b is preferentially sieved or classified, and the fine-grain raw material 10b flows into a pallet (not shown) to form an upper layer portion of the sintering raw material layer. on the other hand,
The coarse-grain raw material 10a slides on the bar screen 15 and flows into a pallet (not shown) to form a lower layer portion of the sintering raw material layer. As shown in FIG. 1, in the powder / granular material sieving apparatus A according to the first embodiment, the distance of the approach chute 13 immediately before the bar screen 15, that is,
The distance between the lower sliding obstacle 16 and the upper end of the bar screen 15 is equal to the pitch L between the two upper and lower sliding obstacles 16, 16.

As described above, in the powder / granular material sieving apparatus A according to the first embodiment, the sliding obstacle 16 provided on the running chute 13 allows the sliding chute 13 to slide on the running surface 13a of the running chute 13. Since the sintering raw material 10 to be formed can be segregated into the coarse-grain raw material 10a forming the upper layer portion and the fine-grain raw material 10b forming the lower layer portion, the fine-grain raw material in the sintering raw material 10 transferred to the bar screen 15 can be obtained. 10b can be preferentially sieved and the coarse grain raw material 10a can be sieved, and the sieving efficiency or classification efficiency of the sintering raw material 10 which is a powder / granular material can be remarkably improved.

In addition, the sintering chute 13 is pressed by the running chute 13.
Can be effectively segregated into the coarse grain raw material 10a and the fine grain raw material 10b in advance, so that it is not necessary to increase the length of the bar screen 15 and the powder / granular material sieving apparatus A can have a compact structure. Since it can be installed in the minimum installation space, it is possible to effectively use the space of a factory or the like and to manufacture at low cost.

Next, the pitch or bar screen 15 between the sliding obstacles 16, 16 used in the first embodiment.
An experiment was carried out on the relationship between the distance L from and the total screen efficiency, and the results are shown in FIG. As is clear from FIG. 3, when the pitch between the sliding obstacles 16 or the distance L between the lower sliding obstacle 16 and the upper end of the bar screen 15 is less than 0.3 m, the overall sieve efficiency is remarkably high. When the pitch or the distance L exceeds 1.2 m, the particle velocity of the sintering raw material 10 becomes too high, and the efficiency is similarly reduced. Therefore, it is preferable that the pitch between the sliding obstacles 16 or the distance L between the lower sliding obstacle 16 and the upper end of the bar screen 15 is 0.3 m to 1.2 m.

Further, an experiment was conducted on the relationship between the height H of the sliding obstacle 16 used in the present embodiment and the overall sieve efficiency, and the results are shown in FIG. As is clear from FIG. 4, when the height H of the sliding obstacle 16 is less than 100 mm, it is not possible to increase the overall efficiency of the sieve, and when the height H exceeds 300 mm. Is a coarse-grain raw material 1 due to an increase in particle falling energy of the sintering raw material 10.
0a and the fine grain raw material 10b are mixed, the segregation of the grain size is reduced, and the overall efficiency of the sieve is lowered. Therefore, it is understood that the height H of the sliding obstacle 16 is preferably 100 mm to 300 mm.

Further, the applicant of the present invention has proposed the conventional powder / granule sieving device in which the sliding obstacle 16 is not provided on the sliding surface 13a of the approaching chute 13 and the powder / granular according to the present embodiment. An experiment on the sieving efficiency was conducted on the product sieving apparatus A, and the experimental conditions and the results are shown in Table 1.

[0019]

[Table 1]

As is clear from Table 1, the powder / granular material sieving apparatus A according to the present embodiment has an overall sieve efficiency of 10% as compared with the conventional powder / granular material sieving apparatus. It turns out that can also be increased.

Next, as shown in FIG. 5, the powder / granular material sieving apparatus B according to the second embodiment is substantially the same as the powder / granular material sieving apparatus A according to the first embodiment. Since they have the same basic configuration, the description of the basic configuration is omitted. As shown in FIG. 5, the powder / granular material sieving apparatus B according to the second embodiment includes three run-up chutes 13 having upper, middle and lower chutes having the same inclination angle as the bar screen 15. 13A, 13B, 13C, the required step h between each other
It is characterized in that it is formed by providing a stepped portion having a stepped arrangement. There should be at least one stepped portion, and therefore, the run-up chute 13 and the upper chute 1
It can also be configured with 3A and the lower shoot 13C.

Next, the sieving operation or classification operation of the sintering raw material 10 by the sieving apparatus B for the powder / granular material having the above-mentioned structure will be described with reference to FIGS. 5 and 6. In FIG. 5, when the raw material cutting feeder 12 is operated, the sintering raw material 10 is dropped and supplied from the hopper 11 onto the running chute 13, and the sintering raw material 10 moves downward on the sliding surface 13 a of the running chute 13. Bar screen 15 located at
You will be descending towards.

However, as shown in FIG. 5, the run-up chute 13 includes three upper, middle, and lower chutes 13A, 13B, 13C arranged with a stepped portion having a step h in a stepwise manner.
As shown in FIG. 6, from the hopper 11, first, the sintering raw material 10 is placed on the upper chute 13A.
Will be dropped and supplied. Then, the sintering raw material 10
Will slide on the sliding surface 13a of the upper chute 13A and fall on the middle chute 13B. At this time, since the step portion formed between the end of the upper chute 13A and the front end of the middle chute 13B has a step h, as shown in FIG. The granular raw material 10a falls to a place far from the step on the sliding surface 13a of the middle chute 13B. On the other hand, of the sintering raw material 10, the fine-grain raw material 10b having a large angle of repose and being hard to roll falls to a place near the step portion. As a result, on the sliding surface 13a of the middle chute 13B, the coarse grain raw material 10 is
The sintering raw material 10 flows in a state where a is segregated in the upper layer portion and the fine grain raw material 10b is segregated in the lower layer portion.

After that, the sintering raw material 10 is the middle stage chute 1
It slides on the sliding surface 13a of 3B and falls on the lower chute 13C. At this time, as shown in FIG. 6, a step portion having a step h is provided between the end of the middle chute 13B and the front end of the lower chute 13C.
As in the case of the upper chute 13A, the coarse grain raw material 10a
Falls to a place far from the step on the sliding surface 13a of the lower chute 13C. On the other hand, the fine-grain raw material 10b falls to a place near the step. As a result, the lower shoot 13C
On the sliding surface 13a of the coarse grain raw material 10a is the upper layer portion,
The segregation of the fine grain raw material 10b in the lower layer portion is further promoted. Thus, on the run-up chute 13 immediately before the bar screen 15, that is, on the lower chute 13C, the coarse grain raw material 10a flows in the upper layer portion and the fine grain raw material 10b flows in the lower layer portion in a substantially completely segregated state. Screen 1
In the sintering raw material 10 transferred to No. 5, the fine-grain raw material 10b is preferentially sieved or classified, and the fine-grain raw material 10b flows into a pallet (not shown) to form an upper layer portion of the sintering raw material layer. become. On the other hand, the coarse grain raw material 10a slides on the bar screen 15 and flows into a pallet (not shown),
The lower layer portion of the sintering raw material layer will be formed.

As described above, in the second embodiment, since the step chute extending over two steps is provided on the run-up chute 13, the sintering raw material 10 is provided in each step with the coarse grain raw material 10a forming the upper layer and the lower layer. Since it can be segregated into the fine-grain raw material 10b forming part, the fine-grain raw material 10b in the sintering raw material 10 transferred to the bar screen 15 can be preferentially sieved and the coarse-grain raw material 10a is sieved. Can be powder
The sieving efficiency or classification efficiency of the sintering raw material 10 which is a granular material can be significantly increased. Also, in the run-up shoot 13,
Since the raw material can be effectively segregated into the coarse-grain raw material 10a and the fine-grain raw material 10b in advance, it is not necessary to increase the length of the bar screen 15, and the sieving apparatus B for the powder / granular material has a compact structure. Since it can be installed in the minimum installation space, it is possible to effectively use the space of a factory or the like and to manufacture at low cost.

Next, an experiment was conducted on the relationship between the shoot inclination angle δ of the run-up chute 13 used in the second embodiment and the overall sieve efficiency, and the results are shown in FIG. As is clear from FIG. 7, the shoot tilt angle δ
Is the highest overall efficiency when the angle of repose α of the fine grain raw material 10b is 35 °, and the overall efficiency of the sieve gradually decreases as the shoot inclination angle δ gradually increases.
The shoot inclination angle δ is the angle of repose of the fine grain raw material 10b 3
It can be seen that it is preferable that the angle is around 5 °. Also, the second
Step h of the approaching chute 13 used in the embodiment
Since we conducted an experiment on the relationship between
FIG. 8 shows the result. As is apparent from FIG. 8, when the step h is less than 50 mm, the overall efficiency of the sieve is still low because the particle size segregation does not occur, and the step h is 300 m.
When it exceeds m, the coarse grain raw material 10a and the fine grain raw material 10b are mixed due to the particle falling energy, and the particle size segregation is reduced. Therefore, the step h is 50 mm to 300 mm
It has been found that

Further, an experiment was carried out on the relationship between the number of steps of the run-up chute 13 used in the second embodiment, that is, the number of steps and the overall sieve efficiency, and the results are shown in FIG. As is clear from FIG. 9, the total sieve efficiency is 60% even when the number of steps is 1, and 67% when the number of steps is 2, and 70% when the number of steps is 3 or more. Therefore, it has been found that the number of steps is preferably 1 to 3. Furthermore, the applicant of the present invention has proposed the conventional powder / granular material sieving device in which the run-up chute 13 has only a single smooth sliding surface 13a, and the powder / granular material sieve according to the second embodiment. An experiment on sieving efficiency was carried out for the separating apparatus B. The experimental conditions and results are shown in Table 2.
Shown in

[0028]

[Table 2]

As is clear from Table 2, the powder / granular material sieving apparatus B according to the second embodiment has a conventional powder
It has been found that the overall sieving efficiency can be increased by as much as 10% compared to a granulate sieving device.

FIG. 10 shows a modified example of the second embodiment. As shown in the figure, this modified example is further provided below the powder / granular material sieving apparatus B including the combination of the run-up chute 13 and the bar screen 15 shown in FIG.
A sieving device B for powder / granular material, which is a combination of an approaching chute 13 and a bar screen 15 having the same structure, is provided. From the end of the bar screen 15 of the sieving device B for powder / granular material in the upper stage. The transfer of the sintering raw material 10 to the run-up chute 13 of the lower-stage powder / granular material sieving apparatus B is
Bar screen 15 of sieving device B for upper powder / granular matter
It is performed by colliding the sintering raw material 10 falling from the end of the above with the collision plate 20 and dropping it onto the upper chute 13A of the approach chute 13. As described above, by sieving the sintering raw material 10 dropped and supplied from the hopper 11 through the sieving apparatus B for the powder / granular material in two stages, the sieving efficiency or the classification efficiency can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a conceptual overall configuration explanatory diagram of a powder / granular material sieving apparatus according to a first embodiment of the present invention.

FIG. 2 is an illustration showing a state of the same sieving operation.

FIG. 3 is a graph showing the relationship between pitch or distance from a bar screen between sliding obstacles and overall sieve efficiency.

FIG. 4 is a graph showing the relationship between the height of a sliding obstacle and the overall sieve efficiency.

FIG. 5 is an explanatory view of the conceptual overall configuration of a powder / granular material sieving apparatus according to a second embodiment of the present invention.

FIG. 6 is an explanatory diagram of a sieving operation of the apparatus.

FIG. 7 is a graph showing a relationship between a shoot angle of an approaching chute and a total efficiency of a sieve.

FIG. 8 is a graph showing a relationship between a step difference of an approaching chute and an overall sieve efficiency.

FIG. 9 is a graph showing the relationship between the number of steps of the run-up chute and the overall sieve efficiency.

FIG. 10 is a conceptual overall configuration explanatory diagram of a powder / granular material sieving apparatus according to a modification of the second embodiment.

FIG. 11 is a conceptual overall configuration explanatory diagram of a powder / granular material sieving apparatus according to a conventional example.

FIG. 12 is an explanatory diagram of a sieving operation of the apparatus.

[Explanation of symbols]

A powder / granular material sieving device B powder / granular material sieving device 10 sintering raw material 10a coarse-grain raw material 10b fine-grain raw material 11 hopper 12 raw material cutting feeder 13 run-up chute 13a sliding surface 13A upper chute 13B middle chute 13C Lower chute 14 Linear member 15 Bar screen 16 Sliding obstacle 17 Slope 20 Collision plate

Claims (5)

[Claims] 1. A raw material composed of powder and granules dropped and supplied onto an approach chute is sieved into a fine-grain raw material and a coarse-grain raw material through a gap of a bar screen provided on a downward extension line of the approach chute. In the method of sieving a powder / granular material to be divided, at least one gliding obstacle is provided on the gliding surface of the running chute, and a repose angle of the raw material is provided above the gliding obstacle depending on the raw material. It is characterized in that a slope is formed, the raw material is segregated into a fine-grain raw material and a coarse-grain raw material by utilizing the slope, and then the raw material is transferred onto the bar screen and sieved. A method for sieving powders and granules. 2. A raw material composed of powder and granules dropped and supplied onto the run-up chute is sieved into a fine-grain raw material and a coarse-grain raw material through a gap of a bar screen provided on a downward extension line of the run-up chute. In the method of sieving powder / granular material, at least one step portion is provided on the run-up chute, and at the step portion, the coarse grain raw material in the raw material is dropped far from the step portion, and A method for sieving powder or granules, characterized in that the fine-grained raw material in the raw material is dropped near the step portion to cause segregation, and then the raw material is transferred to the bar screen for sieving. . 3. A powder / granular material sieving apparatus in which a run-up chute is arranged in an inclined state in the lower part of a hopper, and a bar screen composed of a plurality of linear members is arranged on a downward extension line of the run-up chute. A powder / granular material sieving apparatus, wherein at least one sliding obstacle is provided on the sliding surface of the approach chute. 4. The powder / granule sieving apparatus according to claim 3, wherein the sliding obstacle is formed of a long flat plate protruding in the width direction on the sliding surface of the approach chute. . 5. A powder / granular material sieving apparatus in which a run-up chute is arranged in an inclined state at a lower part of a hopper, and a bar screen made of a plurality of linear members is arranged on a downward extension line of the run-up chute. A powder / granular material sieving apparatus characterized in that at least one step portion is provided on the approach chute.