JP2007275712A - Classifier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a classifier where dispersion performance of a raw material on sieves and the separation of fine powder are excellent. <P>SOLUTION: The classifier is provided with a casing 1 having a charge port 2 of the raw material and a discharging port 3 of product grains, and the sieves 5, 6 that classify the raw material charged from the port 2 into classified powder grains consisting of product grains and fine powder mixed and coarse grains coarser than the product gains and slantly partitioning an internal space of the casing 1 into an upper space 7U and a lower space 7D. The casing 1 is provided with a fine powder separating blower port 11 that sends the air current into the space 7D so as to separate the fine powder from the classified powder grains in the air current, an exhaust outlet 12 that discharges the fine powder separated in the air current together with the air current and a raw material dispersion blowing port 14 that blows the air current for scattering and dispersing the raw material charged from the port 2 in the space 7U. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a classifier used in a dry sand making facility or the like, which is equipped with a sieve, and the charged raw material does not stay in the upper part of the sieve and can efficiently separate product grains from the raw material. .

  In a dry sand making facility, product grains are produced, for example, by the following steps. First, after crushing and crushing large stones, etc. with a crushing and crushing machine, the sieving equipment separates the coarse particles with a larger diameter than the product grains into the separated powder grains containing the product grains. It is collected and re-crushed and pulverized. On the other hand, the finely divided powder is further separated and removed by a cyclone or the like into product particles.

  Since such a manufacturing process requires various sorters, recently, as shown in JP-A-2001-205197 (Patent Document 1) and JP-A-2002-192078 (Patent Document 2), a sieving device is used. In addition, a classifying device has been proposed in which an air stream is directly applied to a raw material to classify into various sized grains according to the weight of the grains and to separate fine powders in an air stream. However, in such a classification device by airflow classification, the classification accuracy tends to fluctuate due to fluctuations in the flow rate and pressure of the classification air flow, and even if the classification air flow is controlled uniformly, adjacent size particles are likely to be mixed, and product particles are sorted. There is a problem that it is inferior in accuracy.

  Japanese Patent Application Laid-Open No. 2003-53268 (Patent Document 3) discloses that a sieve is provided in a casing in order to ensure the accuracy of sorting product grains, and a raw material is put into the casing and the casing is shaken by a vibrator. A classifier that separates the fine powder mixed with the raw material on the sieve and discharges it from the upper exhaust port while moving the raw material over the sieve eye while moving the raw material is proposed. Yes. However, this apparatus has a problem that the fine powder separation efficiency is poor because the fine powder is drawn upward by passing through the raw material layer on the sieve (classification surface).

On the other hand, as shown in FIG. 6, a sieve 36 is provided in a casing 31 in which a pulverized raw material inlet 32 is provided at the top and a product grain outlet 33 is provided at the bottom so that the sieve surface is inclined. There is a classifier in which a blower port 41 for blowing an air flow from the bottom toward the sieve 36 is provided in the center of the bottom of the casing 31.
According to this classifier, the raw material is introduced from the inlet 32 of the casing 31 onto the sieve 36 via the cushion plate 36, and the coarse particles that could not pass through the sieve are recovered from the recovery port 38 and crushed. -Return to the side of the pulverizer 20, re-crush and pulverize, and obtain a fractionated granule (mixed granule of product and fine particles) that has passed through the sieve 36 When the separated powder particles fall toward the bottom of the casing 31, the fine powder mixed in the product particles is separated by airflow by the air flow blown upward from the air blowing port 41. The fine powder separated from the air current is exhausted and collected together with the air flow from the exhaust opening 42 opened below the upper portion of the sieve 36, while the product particles fall downward and are opened at the bottom of the casing 31. It is discharged from 33 and collected. The air flow has not only the separation of airflow of fine powder but also the action of promoting the dispersion movement of the raw material on the sieve 36.
JP 2001-205197 A JP 2002-192078 A JP 2003-53268 A

The classifier shown in FIG. 6 classifies the raw material through a sieve, so that the sorting accuracy is relatively good and the structure is relatively simple. However, the movement resistance of the raw material on the sieve is large. If it is moist, a large amount of raw material may stay in the vicinity of the inlet, and it is necessary to further promote the dispersibility of the raw material in order to increase sorting efficiency. In addition, although the fine powder that has passed through the sieve is finely separated by airflow during the fall process, the separation time tends not to be long, so there is a tendency for separation to be insufficient, and further improvement of the sorting accuracy by fine powder separation. Is required.
The present invention has been made in view of such problems, and an object thereof is to provide a classifier having good dispersibility of raw materials on a sieve and excellent separation of fine powders.

  The classifier according to the present invention is a classifier for classifying product grains of a predetermined size from raw materials, and a casing provided with an inlet for charging the raw material at the top and an outlet for discharging the sorted product grains at the bottom. And a sieve that separates the raw material charged from the inlet into classified powder particles mixed with product particles and fine powder, and coarse particles larger in diameter than the product particles, and the internal space of the casing And a finer separation that blows an air flow into the lower space so as to airflow-separate fine powder from the sorted powder. A blower port for air, an exhaust port for exhausting the fine powder separated from the air flow together with an air flow, and a blower port for material dispersion for blowing an air flow for dispersing the raw material charged from the input port in the upper space. It was provided in That.

  According to this classifier, the air flow for separating the fine powder from the classified powder after passing through the screen is blown from the fine powder separating air outlet, and separately from the air from the fine powder separating air outlet, above the sieve. Since the air flow for dispersing the input raw material is blown from the air outlet for dispersing the raw material, dispersion of the input raw material and separation of the fine powder can be promoted. Thereby, the sorting efficiency and sorting accuracy of product grains can be improved.

  In the classifier, the air outlet for dispersing the raw material is preferably set so that the center line of the blown air flow is within a range of about 10 ° from the substantially horizontal direction to the lower side of the screen. By setting the angle within this range, the dispersion of the raw material in the upper space can be promoted, the wear and damage of the casing inner surface due to the raw material particles scattered by the air flow can be reduced, and the raw material can be reduced. It is possible to prevent powder particles and fine powder separated in the upper space from rising to the inlet side.

  Further, in the classifier, a plurality of receiving plates that are temporarily retained when the sorted powder particles fall toward the bottom in the lower space can be installed at intervals in the horizontal direction and the vertical direction. By providing this backing plate, the falling speed of the separated powder particles can be reduced, and the time during which the separated powder particles receive the air flow for fine powder separation becomes longer, so that the air flow separation of the fine powder can be further promoted. . Moreover, since the separated powder particles that fall one after another accumulate on the backing plate, surface wear is suppressed and durability is also good.

  According to the classifier of the present invention, the air flow for separating the fine powder from the classified powder after passing through the sieve is blown from the fine powder separating air outlet, and separately from the air from the fine powder separating air outlet. Since the air stream for dispersing the input material is blown from the air outlet for dispersing the raw material, the dispersion of the input material and the separation of the fine powder can be promoted, thereby improving the product grain sorting efficiency and the sorting accuracy. be able to.

Hereinafter, an embodiment of a classification device of the present invention will be described with reference to the drawings.
FIG. 1 shows a classification device according to the first embodiment. The classification device includes a casing 1 having a raw material inlet 2 at the top and a product grain outlet 3 at the bottom, and a particle size of the product. A primary sieve 5 for separating large-diameter grains several times larger than the grain size of the grains from the raw material, and primary fractionated grains that are juxtaposed below the primary sieve 5 and passed through the sieve (coarse) of the primary sieve 5 And a secondary sieve 6 having a sieve (fine grain) for separating coarse grains and secondary fractionated grains (mixed grains of product grains and fine grains).

  The primary sieve 5 and the secondary sieve 6 are installed obliquely so as to divide the internal space of the casing 1 diagonally, and an upper space 7U is provided above the primary sieve 5 and a lower part of the secondary sieve 6. Between the primary screen 5 and the secondary screen 6, a space 7 </ b> M is formed between the lower space 7 </ b> D and the secondary screen 6. On the side wall of the casing 1 forming the upper space 7U, a collection port for collecting large-diameter particles separated without passing through the primary sieve 5 and coarse particles separated without passing through the secondary sieve 6 8 is open at the lower end of the primary sieve 5 and the secondary sieve 6. In the upper space 7U, a cushion plate 9 is provided at the lower portion of the charging port 2 to prevent the raw material charged from the charging port 2 from dropping directly onto the primary sieve 5.

  On the side wall of the casing 1 forming the lower space 7D, a fine powder separating air outlet 11 for blowing air so as to blow an air flow from the lateral direction on the secondary fraction powder passing through the secondary sieve 6 and falling. Is opened near the upper portion of the discharge port 3 on the lower end side of the secondary sieve 6, while an exhaust port 12 for exhausting and collecting the air flow together with fine powder is opened on the side wall on the upper end side of the secondary sieve 6. ing.

  Further, when the raw material charged from the charging port 2 falls on the side of the primary sieve 5 via the cushion plate 9 on the side wall of the casing 1 forming the upper space 7U, the raw material is opposite to the charging side in the upper space 7U. The raw material dispersion blower opening 14 for blowing an air flow from the lateral direction is opened so as to be scattered and dispersed in the direction. The air flow is blown into the upper space 7U through an opening provided in a skirt portion suspended from the end portion of the cushion plate 9, and the raw material dispersion blowing port 14 and the opening of the skirt portion are blown ducts. May be connected as appropriate. Of course, the fine powder separating air outlet 11 and the raw material dispersing air outlet 14 are connected in communication with appropriate air sources such as a blower or an air compressor. The air flow blown from the raw material dispersion blower port 14 has a center line direction (arrow direction in the figure) slightly obliquely downward from the horizontal direction toward the screen tilt direction, preferably within 10 °. It is preferable to set.

  According to the classifier, the raw material charged into the charging port 2 falls on the cushion plate 9 and then falls toward the primary sieve 5. At this time, it hits the air flow blown from the raw material dispersion blower port 14 and is scattered in the upper space 7U and falls onto the first sieve 5 in a dispersed state, where it is separated into large diameter grains and primary fractionated grains. The By setting the center line of the air flow blown from the raw material dispersion blower port 14 in the range of about 10 ° from the horizontal direction to the lower side of the sieve inclination, excellent dispersibility of the raw material can be obtained, and the side wall of the casing 1 can be obtained. Therefore, there is an advantage that the inner surface of the casing is prevented from being worn or damaged by the collision of the scattered raw material powder particles, and the raw material powder particles and the fine powder in the raw material are difficult to blow up to the inlet.

  By the 1st sieve 5, a raw material is fractionated into the primary classification powder particle which passed the sieve, and the large diameter particle which was not able to pass. The primary fractionated particles are further classified by the second sieve into secondary fractionated particles (mixed particles of product particles and fine powder) that have passed through the sieve and coarse particles that could not pass through. The large diameter grains and coarse grains are discharged to the outside from the collection port 8 at the lower end of the sieve, returned to the crushing / pulverizing machine 20 again, re-crushed / ground, and added to the raw material.

  On the other hand, in the secondary fraction, the fine powder is separated from the airflow by the airflow blown obliquely upward from the fine powder separation blower port 11 from the lateral direction in the fall process, and the fine powder is exhausted and collected from the exhaust port 12 together with the airflow. The The product particles from which the fine powder has been removed fall as they are to the bottom of the casing 1 and are discharged and collected from the discharge port 3 opened at the bottom.

In the first embodiment, the center line of the air flow blown from the raw material dispersion blower port 14 is slightly inclined downward in the horizontal direction or on the inclined side of the sieve. However, as shown in FIG. It may be slightly upward. Moreover, as shown in FIG. 3, it is good also as a direction which goes to the raw material fall part vicinity of the primary sieve 5 from the upper part of the space 7M between sieves. However, in the case of the air flow for dispersion shown in FIG. 2, the dispersibility in the primary sieve 5 tends to be easily influenced by the deposits in the secondary sieve 6. Further, in the case of the air flow for dispersion shown in FIGS. 2 and 3, when the blast is strengthened, there is a tendency that the inner surface of the casing is worn and the fine powder is easily wound on the inlet.
In the first embodiment, two stages of sieves are provided. However, only the secondary sieve 6 may be used to separate product grains. However, dispersibility and separation of the raw materials can be improved by arranging the primary sieves 5 in parallel as in the present embodiment. Further, the influence of the air flow blown from the fine powder separating air outlet 11 on the upper space 7U can be suppressed, and the winding of the fine powder in the upper space 7U can be suppressed. Moreover, since the interference with the air flow blown from the raw material dispersion air outlet 14 can be suppressed, the dispersibility of the raw material in the upper space 7U can be further improved.

Next, a second embodiment of the classifier of the present invention will be described with reference to FIG. In addition, each part corresponding to the classifier concerning 1st embodiment attaches | subjects the same code | symbol, and abbreviate | omits description.
In the classifier according to this embodiment, in the lower space 7D, the receiving plates 16 for temporarily retaining the secondary sorted powder particles are installed in a staggered manner at intervals in the horizontal direction and the vertical direction. The receiving plate 16 is formed of an L-shaped steel plate including a horizontal plate portion extending in the horizontal direction and a low-profile bent portion in which an end portion on the exhaust port 12 side of the horizontal plate portion is bent upward. Yes. By providing the receiving plate 16, the secondary fractionated powder particles that have passed through the secondary sieve 6 are decelerated when they fall downward, and the time for receiving the air stream that separates the airflow becomes longer, so that the fine powder separation efficiency is improved. In addition, mixing into the product grains can be further suppressed, and as a result, the accuracy of sorting the product grains can be further improved. In addition, since secondary fraction particles that fall one after the other temporarily accumulate on the backing plate 16, surface wear is suppressed and durability is also good. The classifier provided with the backing plate 16 has a product grain sorting efficiency of 1. compared to the conventional type shown in FIG. 6 (however, the sieve is provided with primary and secondary sieves as in the embodiment). About 5 times, the fine powder recovery rate can be improved about 2 times.

  Furthermore, in the classifier according to the first and second embodiments, a floating fines collection port 17 can be provided on the upper wall of the casing 1 as shown in FIG. Thereby, it is possible to collect the floating fine powder that has risen in the upper space 7U, and it is possible to further improve the collection rate of the fine powder.

The longitudinal cross-sectional schematic diagram of the classifier which concerns on 1st Embodiment is shown. In the classifier which concerns on 1st Embodiment, the longitudinal cross-sectional schematic diagram of the modification from which the ventilation direction of the air flow for raw material dispersion | distribution differs is shown. In the classifier which concerns on 1st Embodiment, the longitudinal cross-sectional schematic diagram of the other modification from which the ventilation direction of the air flow for raw material dispersion | distribution differs is shown. The longitudinal cross-sectional schematic diagram of the classifier which concerns on 2nd Embodiment is shown. The longitudinal cross-sectional schematic diagram of the modification of the classifier which concerns on 2nd Embodiment is shown. The longitudinal cross-sectional schematic diagram of the classifier provided with the conventional sieve is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 2 Input port 3 Discharge port 5 Primary sieve 6 Secondary sieve 7U Upper space 7D Lower space 8 Recovery port 11 Fine powder separation ventilation port 12 Exhaust port 14 Raw material dispersion ventilation port 16 Receiving plate

Claims (3)

A classifier for separating product grains of a predetermined size from raw materials,
A casing provided with an inlet for supplying raw material at the top and an outlet for discharging the separated product grains at the bottom;
The raw material charged from the inlet has a sieve that separates the mixed powder into which product particles and fine powder are mixed, and coarse particles larger in diameter than the product particles, and the upper space of the casing Equipped with a screen that divides the space and lower space diagonally,
A collection port for collecting the coarse particles, a fine powder separation blower port for blowing an air flow into the lower space so as to separate fine powder from the sorted powder, and an air flow for exhausting the fine powder separated by the air flow A classifier, wherein the casing is provided with an exhaust port and a raw material dispersing air blowing port for blowing an air flow for dispersing the raw material charged from the charging port in the upper space.   The classifier according to claim 1, wherein the raw material dispersing air outlet is provided so that a center line of an air flow to be blown is within a range of 10 ° from a substantially horizontal direction to a lower side of an inclined side of the sieve. In the lower space, a plurality of receiving plates that are temporarily retained when the separated powder particles fall toward the discharge port are disposed at intervals in the horizontal direction and the vertical direction. The classifier described.

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