JPH0975852A - Airflow classifier - Google Patents
Airflow classifierInfo
- Publication number
- JPH0975852A JPH0975852A JP7238472A JP23847295A JPH0975852A JP H0975852 A JPH0975852 A JP H0975852A JP 7238472 A JP7238472 A JP 7238472A JP 23847295 A JP23847295 A JP 23847295A JP H0975852 A JPH0975852 A JP H0975852A
- Authority
- JP
- Japan
- Prior art keywords
- raw material
- air flow
- classified
- curvature
- coanda
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000002994 raw material Substances 0.000 claims abstract description 54
- 239000000463 material Substances 0.000 claims abstract description 16
- 230000000694 effects Effects 0.000 abstract description 10
- 239000002245 particle Substances 0.000 description 38
- 239000000843 powder Substances 0.000 description 13
- 239000000428 dust Substances 0.000 description 7
- 239000011362 coarse particle Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 238000007599 discharging Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000010298 pulverizing process Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 1
- 230000000593 degrading effect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- UONOETXJSWQNOL-UHFFFAOYSA-N tungsten carbide Chemical compound [W+]#[C-] UONOETXJSWQNOL-UHFFFAOYSA-N 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B07—SEPARATING SOLIDS FROM SOLIDS; SORTING
- B07B—SEPARATING SOLIDS FROM SOLIDS BY SIEVING, SCREENING, SIFTING OR BY USING GAS CURRENTS; SEPARATING BY OTHER DRY METHODS APPLICABLE TO BULK MATERIAL, e.g. LOOSE ARTICLES FIT TO BE HANDLED LIKE BULK MATERIAL
- B07B7/00—Selective separation of solid materials carried by, or dispersed in, gas currents
- B07B7/08—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force
- B07B7/086—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by the winding course of the gas stream
- B07B7/0865—Selective separation of solid materials carried by, or dispersed in, gas currents using centrifugal force generated by the winding course of the gas stream using the coanda effect of the moving gas stream
Landscapes
- Combined Means For Separation Of Solids (AREA)
Abstract
(57)【要約】
【課題】被分級原料を高い精度で分級可能な気流分級機
を提供する。
【解決手段】コアンダブロック７１の原料選別室の一部
を画成する表面が、曲率半径を漸増させた螺線状彎曲面
によって形成されている。原料供給ノズル１６から前記
原料選別室内に高速かつ高遠心力を以て噴出される被分
級原料は、安定した流動状態を保ちながら曲率半径が漸
増する前記螺線状彎曲面のコアンダ効果を享受し、高精
度に気流分級される。
(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide an air stream classifier capable of classifying raw materials to be classified with high accuracy. A surface of a Coanda block 71 that defines a part of a raw material selection chamber is formed by a spiral curved surface with a gradually increasing radius of curvature. The material to be classified ejected from the material supply nozzle 16 into the material selecting chamber at high speed and with high centrifugal force enjoys the Coanda effect of the spiral curved surface in which the radius of curvature gradually increases while maintaining a stable flow state, and the accuracy is high. Is classified by air flow.
Description
【０００１】[0001]
【発明が属する技術分野】本発明は、種々の粒子径の粒
子が混在する被分級原料を固気混相流としてコアンダ効
果を利用して粒子径別に分級する気流分級機に関し、特
にコアンダブロックを改良して前記被分級原料の分級精
度を向上させる気流分級機に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air classifier for classifying raw materials to be classified in which particles having various particle sizes are mixed as a solid-gas mixed phase flow by using the Coanda effect, and particularly improving a Coanda block. The present invention relates to an air stream classifier which improves the classification accuracy of the material to be classified.
【０００２】[0002]
【従来の技術】粉砕処理により微粒子化された原材料
は、通常、粗い粒子のものから非常に細かい粒子のもの
まで様々な粒子径の粒子が混じり合った状態にある。従
って、微粒子化された原材料を工業的に利用する場合に
は、粉砕処理後の原材料に所謂分級処理を施して、所望
の範囲の粒度分布別に分類するようにされている。な
お、ここで言う分級とは、流体中の重力や遠心力または
慣性力で運動する粒子をその粒子径の大きさ毎に分別す
る操作を言い、例えば、複写機用のトナー原料を気流中
に噴射し、コアンダ効果によって生じる粒子径によって
異なる飛散効果経路の差を利用して、該トナー原料を粒
子径別に分級する気流分級機が広く用いられている。2. Description of the Related Art A raw material which has been made into fine particles by a pulverization process is usually in a state in which particles having various particle diameters are mixed, from coarse particles to very fine particles. Therefore, when industrially using the finely divided raw material, the raw material after the pulverization treatment is subjected to a so-called classification treatment so that the raw material is classified according to a particle size distribution in a desired range. Incidentally, the classification here means an operation of classifying particles moving in the fluid by gravity, centrifugal force or inertial force according to the size of the particle diameter, for example, a toner raw material for a copying machine in an air stream. An airflow classifier is widely used which classifies the toner raw material according to the particle size by utilizing the difference in the scattering effect paths which are different depending on the particle size generated by the jetting and the Coanda effect.
【０００３】図５は、このような気流分級機の従来例の
主要部を示す略図である。この気流分級機１は、第１お
よび第２の分級エッジ２、３、並びにコアンダブロック
４及び背面ブロック５によって分岐させた３個の分級用
の排気流路７、８、９が室の出口側に配設されていると
ともに、２個の入気流路１１、１２が室の入り口側に配
設された原料選別室１４と、前記入気流路１１、１２か
ら各排気流路７、８、９に向かって流れる気流を生じさ
せる気流生成手段（図示せず）、例えば排気フアンと、
圧縮気体１９（通常は圧縮空気）を利用して前記原料選
別内に被分級原料１５を圧送、噴射する原材料ノズル１
６とを備えた構成をとっている。FIG. 5 is a schematic view showing a main part of a conventional example of such an air stream classifier. In this air flow classifier 1, three classification exhaust passages 7, 8 and 9 branched by the first and second classifying edges 2 and 3 and the Coanda block 4 and the back block 5 are provided on the outlet side of the chamber. And the exhaust passages 7, 8 and 9 from the raw material selection chamber 14 in which the two intake passages 11 and 12 are disposed on the inlet side of the chamber. An air flow generating means (not shown) for generating an air flow flowing toward, for example, an exhaust fan,
A raw material nozzle 1 that uses compressed gas 19 (usually compressed air) to pump and inject the classified raw material 15 into the raw material selection.
6 and 6.
【０００４】前記被分級原料１５は前記原料供給ノズル
１６内に供給されるとともに、該原料供給ノズル１６に
付与される圧縮気体流１９によって固気混相流として前
記原料選別室１４内に噴射される。前記ノズル１６から
噴出された前記被分級原料１５は、所謂コアンダ効果に
よ前記コアンダブロック４の湾曲した気流接触面に沿っ
て移動し、前記被分級原料１５に対し遠心力が働き、該
原料１５内の比較的粗い粒子は前記コアンダブロック４
に沿って流れている噴流から外れて飛び出す。前記コア
ンダブロック４の湾曲した気流接触面に沿って流れる噴
流の外側には、前記入気流路１１、１２から前記各排気
流路７、８、９に向かう気流が流れているので、前記噴
流から外側に飛び出した前記被分級原料１５の内比較的
粗い粒子は、この気流による粒子毎に異なる飛散降下経
路の差によって所定の粒度分布範囲毎に該当の排気流路
７、８、９に対し分別排出されるようになっている。The raw material 15 to be classified is supplied into the raw material supply nozzle 16 and is injected into the raw material selection chamber 14 as a solid-gas multiphase flow by a compressed gas flow 19 applied to the raw material supply nozzle 16. . The classified raw material 15 ejected from the nozzle 16 moves along the curved air flow contact surface of the Coanda block 4 by the so-called Coanda effect, and centrifugal force acts on the classified raw material 15 to cause the raw material 15 to flow. The relatively coarse particles inside are the Coanda block 4
It jumps out of the jet that is flowing along. Outside the jet flow flowing along the curved air flow contact surface of the Coanda block 4, the air flow heading from the intake air flow passages 11, 12 to the exhaust flow passages 7, 8, 9 flows from the jet flow. The relatively coarse particles in the classified raw material 15 that have flown out to the outside are separated from the corresponding exhaust flow paths 7, 8 and 9 for each predetermined particle size distribution range due to the difference in the scattering and descending paths that differ for each particle due to this air flow. It is supposed to be discharged.
【０００５】前記コアンダ効果が作用する粒子の飛散降
下経路は、その粒子径が小さく慣性も小さいほどその曲
率半径を小さくして前記コアンダロック４の湾曲した気
流接触面に沿って粒子を飛散降下させながら、該コアン
ダブロック４に最も近い前記排気流路７に排出させる。
これに対してその粒子径及び慣性がそれぞれ大きい粒子
は、前記飛散降下経路の曲率半径が大きく、前記コアン
ダブロック４から最も遠い軌跡を描いて飛散する。そし
て、前記排気流路９には、この最も粒子径の大きい粒度
分布を示す産物が排出される。また、前記排気流路７、
８は、前記コアンダブロック４に最も近い排気流路７が
最も粒子径の小さい粒度分布を示す産物のための微粉末
排出用として、中間に位置する排気流路８が中間の大き
さの粒度分布を示す産物のための中粉末排出用として、
各々適用される。そして、前記各排気流路７、８、９に
排出された前記被分級原料１５は、該流路７、８、９に
接続されている集塵機（図示せず）により集められ、空
気と分離される。The particle scattering descent path on which the Coanda effect acts has a smaller radius of curvature as the particle size and inertia are smaller so that the particles scatter and descent along the curved air flow contact surface of the Coanda lock 4. Meanwhile, the gas is discharged to the exhaust passage 7 closest to the Coanda block 4.
On the other hand, a particle having a large particle diameter and a large inertia has a large radius of curvature of the scattering descent path, and scatters along a trajectory farthest from the Coanda block 4. Then, the product having the largest particle size and having a particle size distribution is discharged to the exhaust passage 9. In addition, the exhaust passage 7,
The exhaust passage 8 closest to the Coanda block 4 is for discharging fine powder for a product having a particle size distribution with the smallest particle size, and the exhaust passage 8 located in the middle has a particle size distribution of the intermediate size. For discharging medium powder for products showing
Applied to each. Then, the classified material 15 discharged to the exhaust passages 7, 8 and 9 is collected by a dust collector (not shown) connected to the passages 7, 8 and 9 and separated from air. It
【０００６】[0006]
【発明が解決しようとする課題】ところで、従来におい
てはこの種の装置の基本技術が特公昭５５−６４３３号
公報に開示されている。ここに示されたコアンダブロッ
クの構造は、その概念図として図６に示すように、原料
供給ノズル１６の先端部に位置するコアンダブロック４
の湾曲した気流接触面が単一の曲率半径（Ｒ1）を以て
設定された構成、さらには図７に示すように、前記気流
接触面の曲率半径を前記原料供給ノズル１６の先端部側
から下流方向に減少させた所謂複合曲率半径（Ｒ1＞
Ｒ2）に設定した構成である。そして、上記公報におい
は、コアンダブロックにおける気流接触面の湾曲形態
は、特定条件下においては図７に示したように、その曲
率半径が流体下流側に行くのに伴って小さくなる構成が
好ましい（公報の第６図に示された構成）といった記載
がなされている。By the way, conventionally, the basic technique of this type of apparatus is disclosed in Japanese Patent Publication No. 55-6433. The structure of the Coanda block 4 shown here is, as a conceptual diagram thereof, shown in FIG.
Of the curved airflow contact surface is set with a single radius of curvature (R 1 ), and as shown in FIG. 7, the radius of curvature of the airflow contact surface is changed from the tip side of the raw material supply nozzle 16 to the downstream side. So-called compound radius of curvature (R 1 >
R 2 ). Further, in the above publication, the curved shape of the air flow contact surface in the Coanda block is preferably configured such that the radius of curvature thereof becomes smaller as it goes to the downstream side of the fluid under specific conditions, as shown in FIG. The configuration shown in FIG. 6 of the publication) is described.
【０００７】一方、最近特に要求の多くなった、数ミク
ロンオーダーの極めて微細な粒子の分級に於いては、気
流の乱れによる分級精度の低下の影響が大きくなるもの
と考えられる。この気流の乱れは、分級機を構成する各
部の形状に大きく関係する。例えばコアンダブロックと
気流の境界面に於いては、コアンダ効果により、コアン
ダブロックの曲率半径に沿って気流が流れる。ところ
が、コアンダ効果は、下流に行くに従って、気流とコア
ンダブロックの間に生じる負圧の低下によって、少しず
つ小さくなり、最終的には消滅してしまう。この現象に
より、気流は、コアンダブロックから離れていき、その
部分で２次気流が生じることにより、気流の乱れが発生
し、分級精度が低下する。また、気流がコアンダブロッ
クから剥離してしまい、十分な遠心力場が得られなくな
る。更に、この状態が、コアンダブロックの曲率半径の
ごく始まりの部分（上流側部分）で起こると、所謂コア
ンダ離れ（気流乱れ状態）という状態になり、分級精度
は全く落ちてしまう。On the other hand, in the classification of extremely fine particles of the order of several microns, which has recently been particularly demanded, it is considered that the influence of the deterioration of the classification accuracy due to the turbulence of the air flow becomes large. The turbulence of the air flow is greatly related to the shape of each part that constitutes the classifier. For example, at the boundary surface between the Coanda block and the airflow, the airflow flows along the radius of curvature of the Coanda block due to the Coanda effect. However, the Coanda effect gradually decreases as it goes downstream, due to the decrease in the negative pressure generated between the airflow and the Coanda block, and eventually disappears. Due to this phenomenon, the air flow moves away from the Coanda block, and a secondary air flow is generated in that part, causing turbulence of the air flow and degrading the classification accuracy. Further, the air flow is separated from the Coanda block, and a sufficient centrifugal force field cannot be obtained. Furthermore, if this state occurs at the very beginning portion (upstream side portion) of the radius of curvature of the Coanda block, the state becomes so-called Coanda separation (air flow turbulence state), and the classification accuracy is completely deteriorated.
【０００８】そこで、本発明の目的は前述した従来技術
の問題点を解消することにあり、気流の乱れ及びコアン
ダ離れを起こすことなく、高い精度で分級することが可
能な気流分級機を提供することにある。Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an airflow classifier which can perform classification with high accuracy without causing turbulence of airflow and separation of Coanda. Especially.
【０００９】[0009]
【課題を解決するための手段】本発明のかかる目的は、
原料選別室と、前記原料選別室に連通する入気流路及び
複数に分岐させた排気流路と、前記原料選別室内に突出
する湾曲した気流接触面を有するコアンダブロックと、
前記気流接触面に沿って前記原料選別室内に噴出される
圧縮気体の流れに被分級原料を乗せた気流を形成する原
料供給ノズルとを有する気流分級機において、前記コア
ンダブロックの気流接触面がその曲率半径を前記気流の
下流に向かって漸増する螺旋状湾曲面に形成されたこと
を特徴とする気流分級機によって達成することができ
る。The object of the present invention is to:
A raw material sorting chamber, an inlet air flow passage communicating with the raw material sorting chamber and an exhaust flow passage branched into a plurality, a Coanda block having a curved air flow contact surface protruding into the raw material sorting chamber,
In an air stream classifier having a raw material supply nozzle that forms an air stream in which a material to be classified is placed on a flow of a compressed gas ejected into the raw material sorting chamber along the air stream contact surface, the air stream contact surface of the Coanda block is This can be achieved by an airflow classifier characterized in that the radius of curvature is formed in a spiral curved surface that gradually increases toward the downstream of the airflow.
【００１０】また、本発明のかかる目的は、前記コアン
ダブロックの螺旋状湾曲面が前記曲率半径を１５乃至２
５mmに漸増させてなることを特徴とする気流分級機によ
って達成することができる。Another object of the present invention is that the spiral curved surface of the Coanda block has a radius of curvature of 15 to 2.
This can be achieved by an airflow classifier characterized by being gradually increased to 5 mm.
【００１１】このように本発明の気流分級機におけるコ
アンダブロックに沿って噴出された気流（固気混相流）
は、コアンダブロックの曲率半径の比較的小さい曲率半
径（Ｒ1 ）を有した前記螺旋状湾曲面の表面に沿って移
動し、次第に連続的にその曲率半径が大きくなり最終曲
率半径（Ｒ2 ）に達するように変化する前記螺旋状湾曲
面の半径が漸次連続的に大きくなっていくことで、気流
とコアンダブロックの境界面に生じる負圧の低下を効果
的に補うことができ、気流の乱れを生じにくくすること
が可能となる。Thus, the airflow (solid-gas mixed phase flow) ejected along the Coanda block in the airflow classifier of the present invention
Moves along the surface of the spiral curved surface having a relatively small radius of curvature (R 1 ) of the Coanda block, and the radius of curvature gradually increases to a final radius of curvature (R 2 ). By gradually and continuously increasing the radius of the spiral curved surface that changes so as to reach, it is possible to effectively compensate for the decrease in negative pressure that occurs at the boundary surface between the air flow and the Coanda block. Can be prevented.
【００１２】[0012]
【発明の実施の形態】本発明に係る気流分級機の一実施
例を添付した図面に基づいて詳細に説明する。ここで、
図１は気流分級機の主要部を拡大しかつ概念的に示した
縦断面図、図２は図１におけるコアンダブロックを拡大
して示した縦断面図、図３は図１に示す気流分級機にお
ける気流分級機の作動を模式的に示す図面、図４は本発
明に係る実施例の気流分級機を含めた設備の全体構成を
概念的に示す図である。なお、以下の説明においては、
従来の気流分級機１と同一の部分には同一の符号を用い
てその説明を省略する。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of an air classifier according to the present invention will be described in detail with reference to the accompanying drawings. here,
FIG. 1 is an enlarged and conceptually longitudinal sectional view showing a main part of the airflow classifier, FIG. 2 is an enlarged longitudinal sectional view showing a Coanda block in FIG. 1, and FIG. 3 is an airflow classifier shown in FIG. FIG. 4 is a drawing schematically showing the operation of the air flow classifier in FIG. 4, and FIG. 4 is a diagram conceptually showing the overall configuration of the equipment including the air flow classifier of the embodiment according to the present invention. In the following description,
The same parts as those of the conventional airflow classifier 1 are designated by the same reference numerals and the description thereof will be omitted.
【００１３】まず、図４に示す全体的な設備について概
略的に説明する。図４に示すように、気流分級設備１０
０は、例えば適宜粉砕等の工程を経た被分級原料１５を
適当な管路を介してホッパ３３に供給する。ホッパー３
３から定量フィーダ３４を介して供給された原料は圧縮
空気と混合されて、固気混相流として原料供給ノズル１
６から気流分級機７０の分級空間に噴出される。前記気
流分級機７０によって気流分級された粒子をそれぞれ集
塵する集塵機３６・３７・３８並びに図示しない適宜吸
引ポンプ等を備えている。First, the overall equipment shown in FIG. 4 will be briefly described. As shown in FIG. 4, airflow classification equipment 10
In the case of 0, for example, the material 15 to be classified, which has been appropriately crushed and the like, is supplied to the hopper 33 through a suitable pipe line. Hopper 3
The raw material supplied from No. 3 through the fixed amount feeder 34 is mixed with compressed air to form a solid-gas mixed phase flow in the raw material supply nozzle 1
It is jetted from 6 into the classification space of the airflow classifier 70. The apparatus is provided with dust collectors 36, 37, 38 for collecting the particles classified by the air stream classifier 70, a suction pump (not shown), and the like.
【００１４】そして、前記被分級原料１５は前記気流分
級機７０により気流分級され、製品とする粒子よりも小
さい粒子径を有する粒子は微粉末として前記集塵機３６
に、製品とする粒子は中粉末として前記集塵機３７に、
製品とする粒子よりも大きい粒子径を有する粒子は粗粉
末として前記集塵機３８にそれぞれ集塵される。Then, the material to be classified 15 is air-flow classified by the air-flow classifier 70, and the particles having a particle size smaller than that of the product particles are fine powder as the dust collector 36.
In addition, the particles to be the product are the intermediate powder in the dust collector 37,
Particles having a particle size larger than that of the product particles are collected by the dust collector 38 as coarse powder.
【００１５】次に、本実施例の気流分級機７０の作動に
ついて、図１および図３を参照して説明する。ここに、
前記被分級原料１５は前記原料供給ノズル１６に供給さ
れるとともに、該原料供給ノズル１６に供給される圧縮
気体流１９によって分散させられて、固気混相流として
前述の如く前記原料供給ノズル１６から前記原料選別室
１４内に噴射される。Next, the operation of the airflow classifier 70 of this embodiment will be described with reference to FIGS. 1 and 3. here,
The material 15 to be classified is supplied to the material supply nozzle 16 and dispersed by a compressed gas flow 19 supplied to the material supply nozzle 16 to form a solid-gas multiphase flow from the material supply nozzle 16 as described above. It is injected into the raw material selection chamber 14.
【００１６】そして、前記原料供給ノズル１６から前記
原料選別室１４内に噴射された前記被分級原料１５を含
む噴流は、コアンダ効果により前記コアンダブロック７
１に沿って流れ、前記被分級原料１５に遠心力が働き、
該被分級原料１５内の比較的粗い粒子は前記コアンダブ
ロック７１に沿って流れる噴流から外に飛び出す。前記
コアンダブロック７１に沿って流れる噴流の外側には、
入気流路１１、１２から各排気流路７、８、９に向かう
気流が流れ、前記コアンダブロック７１に沿って流れる
噴流から外側に向かって飛び出した前記被分級原料１５
内の比較的粗い粒子は、この気流による粒子毎に異なる
飛散経路の差によって所定の粒径範囲毎に該当する前記
排気流路７、８、９に分別排出される。The jet flow containing the raw material 15 to be classified injected from the raw material supply nozzle 16 into the raw material sorting chamber 14 is caused by the Coanda effect.
1, a centrifugal force acts on the material 15 to be classified,
The relatively coarse particles in the raw material 15 to be classified fly out from the jet flowing along the Coanda block 71. Outside the jet flowing along the Coanda block 71,
An airflow flowing from the intake air passages 11, 12 to the respective exhaust passages 7, 8, 9 flows out of the jet flow flowing along the Coanda block 71 toward the outside.
The relatively coarse particles therein are separated and discharged to the exhaust passages 7, 8 and 9 corresponding to each predetermined particle size range due to the difference in the scattering paths that differ for each particle due to the air flow.
【００１７】前記コアンダ効果が作用する粒子の飛散降
下経路は、粒子径が小さく慣性の小さいものほどその曲
率半径が小さく、前記コアンダブロック７１の気流接触
面に沿って飛散降下して前記コアンダブロック７１に最
も近い前記排気流路７に排出される。これに対して、粒
子径が大きく慣性の大きいものほど飛散降下経路の曲率
半径が大きく、前記コアンダブロック７１から遠く離れ
るように飛散降下して、前記コアンダブロック７１から
最も遠い前記排気流路９に排出される。すなわち、図３
にも示すように、前記原料供給ノズル１６により原料選
別室１４内に噴出された前記被分級原料１５は、最も粒
子径の大きい粒子が前記背面ブロック５側に最も接近し
て飛散降下して粗粉の分布領域に、一方、コアンダブロ
ック７１側に微粉分布の領域が形成され、またこれらの
中間に中粉の分布領域が形成される。そして、各排気流
路７、８、９に排出された前記被分級原料１５は、各排
気流路７、８、９に管路２１、２２、２３を介して接続
された集塵機によってそれぞれ集塵され、もって粉体と
空気とに分けられる。The particle scattering and descending path on which the Coanda effect acts has a smaller radius of curvature as the particle size is smaller and the inertia is smaller, and scatters and descends along the air flow contact surface of the Coanda block 71. Is discharged to the exhaust passage 7 closest to On the other hand, the larger the particle diameter and the larger the inertia, the larger the radius of curvature of the scattering descent path, and scatters and descends far away from the Coanda block 71 to the exhaust passage 9 farthest from the Coanda block 71. Is discharged. That is, FIG.
As also shown in the figure, in the classified raw material 15 jetted into the raw material sorting chamber 14 by the raw material supply nozzle 16, the particles having the largest particle diameter are closest to the rear block 5 side and are scattered and fall down. In the powder distribution region, on the other hand, a fine powder distribution region is formed on the Coanda block 71 side, and a medium powder distribution region is formed in between. Then, the classified raw material 15 discharged to the exhaust passages 7, 8 and 9 is collected by a dust collector connected to the exhaust passages 7, 8 and 9 via pipes 21, 22 and 23, respectively. Then, it is divided into powder and air.
【００１８】本実施例における前記コアンダブロック７
１の構成について図２を参照してさらに詳述する。この
コアンダブロック７１の前記螺旋状湾曲面７２は前記原
料供給ノズル１６の噴出先端部に隣接する領域から前方
下方に向かって反時計回り方向へ約１３５°乃至１４５
°湾曲した領域にわたり連続的にその曲率半径（Ｒ1→
Ｒ2）を漸増させて形成されていることに特徴がある。
前記曲率半径（Ｒ1→Ｒ2）は，例えば、前記原料供給ノ
ズル１６寄りが１５mmから始まり、前記排気流路７寄り
において最終的に２５mmになるような漸増パターンを以
て設定されている。なお、前記螺旋状湾曲面７１及びそ
れに引き続く気流接触面７３は、タングステン・カーバ
イド等によりその表面硬化処理を施し、耐磨耗性を高め
ることが好ましい。The Coanda block 7 in this embodiment.
1 will be described in more detail with reference to FIG. The spiral curved surface 72 of the Coanda block 71 is about 135 ° to 145 in the counterclockwise direction from the region adjacent to the ejection tip of the raw material supply nozzle 16 toward the lower front.
° The radius of curvature (R 1 →
It is characterized in that it is formed by gradually increasing R 2 ).
The radius of curvature (R 1 → R 2 ) is set, for example, in a gradually increasing pattern in which the material supply nozzle 16 starts at 15 mm and finally reaches 25 mm at the exhaust passage 7. It is preferable that the spiral curved surface 71 and the airflow contact surface 73 subsequent thereto are subjected to surface hardening treatment with tungsten carbide or the like to improve wear resistance.
【００１９】前述したように構成される本発明の気流分
級機における前記コアンダブロック７１は、前記原料供
給ノズル１６から前記原料選別室１４内に高速で、高い
遠心力を以て噴射された前記被分級原料１５を、前記曲
率半径（Ｒ1→Ｒ2）を漸増させて形成されている前記螺
旋状湾曲面７２に沿って、気流の乱れを極力無くし、ま
た前述したコアンダ離れを発生させることなくより安定
した状態で、引きつけるように作用して気流分級するこ
とが可能になり、従って、その気流分級の歩留りや精度
も一層向上させることが可能になった。これにより、第
１および第２の分級エッジ２・３の間隔を大きく設定す
ることができるので、前記被分級原料１５を分級する精
度を向上させることができて、製品とする中粉末の粒度
品質を向上させることが容易になる。The Coanda block 71 in the airflow classifier of the present invention constructed as described above is the raw material to be classified which is injected from the raw material supply nozzle 16 into the raw material sorting chamber 14 at high speed and with high centrifugal force. 15 is more stable along the spiral curved surface 72 formed by gradually increasing the radius of curvature (R 1 → R 2 ) to minimize turbulence of the airflow and to prevent the above-mentioned Coanda separation. In such a state, it becomes possible to perform the airflow classification by acting so as to attract, and therefore, it becomes possible to further improve the yield and accuracy of the airflow classification. As a result, the interval between the first and second classification edges 2 and 3 can be set large, so that the accuracy of classifying the material 15 to be classified can be improved, and the particle size quality of the medium powder to be the product can be improved. It becomes easy to improve.
【００２０】本発明の気流分級機のテストとしては、図
２に示した構成、すなわち、螺旋状湾曲面７２は原料供
給ノズル１６の噴出先端部に隣接する領域から反時計回
り方向へ約１３５°乃至１４５°湾曲した領域にわたり
連続的に曲率半径（Ｒ1→Ｒ2）が漸増した構成で、且つ
曲率半径（Ｒ1→Ｒ2）は原料供給ノズル１６寄りが１５
mmから始まり、排気流路７寄りにおいて最終的に２５mm
になる構成のものを使用した。また、原料供給ノズル１
６から噴出される気流の速度は１８０〜２５０ｍ／ｓと
し、平均粒径が５〜６μｍのトナー原料を用いてテスト
を繰り返し行った。この結果、微粉末、中粉末および粗
粉末の分布のばらつきに関しては、従来のものに比べて
８０％程度よく分級精度のよい結果を得ることができ
た。As a test of the air stream classifier of the present invention, the configuration shown in FIG. 2, that is, the spiral curved surface 72 is rotated about 135 ° in the counterclockwise direction from the region adjacent to the ejection tip of the raw material supply nozzle 16. The radius of curvature (R 1 → R 2 ) is gradually increased over a region curved by 145 ° to 145 °, and the radius of curvature (R 1 → R 2 ) is 15 near the raw material supply nozzle 16.
Starting from mm, and finally 25 mm near the exhaust flow path 7
I used the one with the configuration. In addition, the raw material supply nozzle 1
The velocity of the air flow ejected from No. 6 was 180 to 250 m / s, and the test was repeated using a toner raw material having an average particle size of 5 to 6 μm. As a result, with respect to the dispersion of the distribution of the fine powder, the medium powder and the coarse powder, it was possible to obtain a result with good classification accuracy by about 80% as compared with the conventional one.
【００２１】[0021]
【発明の効果】以上詳述したように、本発明の気流分級
機においては、コアンダブロックに沿って噴出された気
流が、コアンダブロックの曲率半径の比較的小さい曲率
半径を有した前記螺旋状湾曲面の表面に沿って移動し、
次第に連続的にその曲率半径が大きくなり最終曲率半径
に達するように変化する前記螺旋状湾曲面によって案内
される。このようにコアンダブロックの気流接触面の半
径が漸次連続的に大きくなっていくとことで、前記気流
がコアンダブロックに沿って回り込むために必要な負圧
力を小さく抑えることが可能となるので、原料供給ノズ
ルからの気流噴出速度を速く設定しても、コアンダ離れ
及び気流の乱れが発生することなく安定した状態を保っ
て広い範囲の飛散降下経路を形成することができ、精度
の高い分級処理が可能となる。As described in detail above, in the airflow classifier of the present invention, the airflow ejected along the Coanda block has the spiral curvature having a relatively small radius of curvature of the Coanda block. Move along the surface of the face,
It is guided by the spiral curved surface which gradually and continuously increases its radius of curvature and changes so as to reach the final radius of curvature. By gradually increasing the radius of the air contact surface of the Coanda block in this manner, it is possible to suppress the negative pressure required for the air flow to go around along the Coanda block to be small. Even if the airflow ejection speed from the supply nozzle is set to a high speed, it is possible to maintain a stable state without leaving Coanda and turbulence of the airflow, and to form a wide range of scattering and descending paths, which enables highly accurate classification processing. It will be possible.
【図１】本発明の気流分級機の主要部を示した縦断面図
である。FIG. 1 is a vertical sectional view showing a main part of an airflow classifier according to the present invention.
【図２】図１に示したコアンダブロックを拡大して示し
た縦断面図である。FIG. 2 is an enlarged vertical sectional view of a Coanda block shown in FIG.
【図３】気流分級機の分級形態を模式的に示した説明図
である。FIG. 3 is an explanatory view schematically showing a classification form of an airflow classifier.
【図４】本発明に係る気流分級設備の全体構成を示した
概略図である。FIG. 4 is a schematic diagram showing the overall configuration of an airflow classification facility according to the present invention.
【図５】従来の気流分級機の主要部を拡大して示した縦
断面図である。FIG. 5 is an enlarged vertical sectional view showing a main part of a conventional airflow classifier.
【図６】従来のコアンダブロックを示す概略図である。FIG. 6 is a schematic view showing a conventional Coanda block.
【図７】従来のコアンダブロックを示す概略図である。FIG. 7 is a schematic view showing a conventional Coanda block.
１、７０ 気流分級機 ２、３ 分級エッジ ４、７１ コアンダブロック ５ 背面ブロック ７、８、９ 排気流路 １１、１２ 入気流路 １４ 原料選別室 １５ 被分級原料 １６ 原料供給ノズル ３２、３６、３７、３８ 集塵機 ４０ 振動ふるい ５０ 粉砕機 ７２ 螺旋状湾曲面 1, 70 Air flow classifier 2, 3 Classification edge 4, 71 Coanda block 5 Back block 7, 8, 9 Exhaust flow channel 11, 12 Inlet flow channel 14 Raw material selection chamber 15 Classified raw material 16 Raw material supply nozzle 32, 36, 37 , 38 Dust collector 40 Vibration sieve 50 Crusher 72 Spiral curved surface
Claims (2)
入気流路及び複数に分岐させた排気流路と、前記原料選
別室内に突出する湾曲した気流接触面を有するコアンダ
ブロックと、前記気流接触面に沿って前記原料選別室内
に噴出される圧縮気体の流れに被分級原料を乗せた気流
を形成する原料供給ノズルとを有する気流分級機におい
て、 前記コアンダブロックの気流接触面がその曲率半径を前
記気流の下流に向かって漸増する螺旋状湾曲面に形成さ
れたことを特徴とする気流分級機。1. A raw material sorting chamber, an inlet flow passage communicating with the raw material sorting chamber and an exhaust flow passage branched into a plurality, a Coanda block having a curved air flow contact surface protruding into the raw material sorting chamber, An air flow classifier having a raw material supply nozzle that forms an air flow in which a material to be classified is placed on a flow of compressed gas ejected into the raw material selection chamber along the air flow contact surface, wherein the air flow contact surface of the Coanda block has a curvature An air flow classifier, wherein the air flow classifier is formed in a spiral curved surface whose radius gradually increases toward the downstream of the air flow.
記曲率半径を１５乃至２５mmに漸増させてなることを特
徴とする気流分級機。2. An air flow classifier, wherein the spiral curved surface of the Coanda block is formed by gradually increasing the radius of curvature to 15 to 25 mm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23847295A JP3679163B2 (en) | 1995-09-18 | 1995-09-18 | Airflow classifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23847295A JP3679163B2 (en) | 1995-09-18 | 1995-09-18 | Airflow classifier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0975852A true JPH0975852A (en) | 1997-03-25 |
| JP3679163B2 JP3679163B2 (en) | 2005-08-03 |
Family
ID=17030751
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23847295A Expired - Fee Related JP3679163B2 (en) | 1995-09-18 | 1995-09-18 | Airflow classifier |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3679163B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108031648A (en) * | 2017-11-30 | 2018-05-15 | 安徽省恒伟铋业有限公司 | A kind of powder screening machine |
| JP2018086627A (en) * | 2016-11-29 | 2018-06-07 | 日鉄鉱業株式会社 | Two-class classifier by air flow |
-
1995
- 1995-09-18 JP JP23847295A patent/JP3679163B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2018086627A (en) * | 2016-11-29 | 2018-06-07 | 日鉄鉱業株式会社 | Two-class classifier by air flow |
| CN108031648A (en) * | 2017-11-30 | 2018-05-15 | 安徽省恒伟铋业有限公司 | A kind of powder screening machine |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3679163B2 (en) | 2005-08-03 |
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