JP3335312B2 - Jet mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a horizontal swirl type jet mill.

[0002]

2. Description of the Related Art In recent years, it has been used in various fields such as generation of heat-sensitive powder or ceramic powder such as pesticides and toners.
Various jet mills have been developed in which fine particles are crushed by colliding powders with each other using a high-speed jet. For example,
In Japanese Patent Application Publication No. 3-16981 (hereinafter referred to as “A”),
`` A part of the outer periphery of the circular separation chamber faces the collision space between the collision plate facing the outlet of the high-pressure gas injection main nozzle and the nozzle outlet, and communicates with this circular separation chamber and the middle of the main nozzle. A supersonic jet mill in which the outlet side of the raw material supply passage is communicated with a bypass passage extending in a direction tangential to the outer periphery of the circular separation chamber, and a discharge path for fine powder is connected to the center of the circular separation chamber. '' . Further, similar configurations are disclosed in JP-A-57-50554, JP-A-57-50555, JP-A-57-50556, and JP-A-4-2905.
No. 60, No. 5-184966, No. 7-275
Nos. 731 and 8-152742 and 8-15
No. 5324, No. 8-182937, No. 8-2
No. 54855, No. 8-323234, Japanese Utility Model Publication No. 3-52110, No. 7-53715, No. 7
Japanese Patent Application Laid-Open Nos. -8036 and 6-19836 are known. Japanese Patent Publication No. 63-17501 (hereinafter referred to as “B”) discloses that a solid-gas mixing chamber having a raw material supply port and a crushing material supply nozzle for jetting high-pressure gas is formed at one end and opened at the other end. An impingement plate is provided and a revolving pulverization chamber provided with a pulverization nozzle for ejecting high-pressure gas is formed, and one end of the solid-gas mixing chamber and one end of the revolving pulverization chamber are communicated by an acceleration tube opposed to the impingement plate. Forming a classifying chamber on the outer periphery of the accelerating tube through the rectifying zone and communicating with the revolving and crushing chamber, further providing an annular classifying plate surrounding the accelerating tube in the classifying chamber, and the inner side of the classifying plate as a discharge hole, A jet mill having a configuration in which the outside communicates with the solid-gas mixing chamber ”is disclosed. Japanese Patent Publication No. 64-905
Japanese Patent Publication No. 7 (hereinafter referred to as “Patent Publication C”) has improved the jet mill described in the Publication No. “B” and has described a “jet plate provided with a projection (center pole) having a center portion most protruding toward the outlet center of the acceleration tube on the collision plate. Mill "is disclosed. JP-A-6-254
No. 427 (hereinafter referred to as "No. 2") discloses "a plurality of pulverizing nozzles for forming a swirling flow by injecting a high-pressure gas into a swirling pulverizing chamber, and a collision provided opposite to an injection port of each pulverizing nozzle. The impact member is a flat collision plate in which the shape of the lower end and the upper end along the swirling flow direction is thinly formed in a blade-like shape, and the collision surface thereof is the flow of the swirling flow. A jet mill is disclosed in which the angle α formed in the direction and the center line of the opposing crushing nozzle is inclined in the range of 30 to 60 degrees and fixed by mounting means capable of adjusting the angle. Japanese Patent Application Laid-Open No. HEI 2-111449 (hereinafter referred to as “E”) discloses that “the spread angle of an acceleration tube is 7 ° to 9 °.
° jet mill ". Also,
As a similar one, Japanese Utility Model Publication No. Hei 7-25227 is known. Further, in the conventional jet mill, the layout design of the crushing material supply nozzle and the injection nozzle for injecting the high pressure gas is performed by arranging the injection nozzle at a position equally dividing the circumference of the orbiting crushing chamber, so that the crushing material supply nozzle is used. One minute between the injection nozzles
The nozzles were arranged at different locations and the total number of nozzles was odd.

[0003]

However, the above-mentioned conventional jet mill has the following problems. In the jet mill described in JP-A No., etc., when a crushing material, for example, a new ceramic crushing material having a high hardness collides with the jet flow of the high-pressure gas on the fixed wall, abrasion is formed from the colliding portion to form a recess, There has been a problem that the fixed wall is worn out in a short time and the durability is extremely poor. The jet mill described in Japanese Patent Application Publication No. H08-27205 has the same problems as the Japanese Patent Application Publication No. A-2006, and also supplies the raw material to the central part (decompression part) of the swirling airflow. Is low,
There was a problem that the particle size distribution was significantly widened. In the jet mill described in Japanese Patent Application Publication No. JP-A-2006-129, the supply of the crushing material and the discharge of the fine powder are both performed in the upper part of the whirl crushing chamber, so that the normal flow of the whirl flow forming the crushing nozzle is greatly disturbed. Such a turbulence in the swirling flow increases the pressure loss and consequently lowers the speed of the swirling flow, so that there is a problem that the pulverizing ability is lacking. The jet mill described in Japanese Patent Application Laid-Open Publication No. H06-27207 utilizes the collision action of four collision plates provided in the rotary crushing chamber and is excellent in crushing efficiency. , The powder has a rectangular shape, and it is difficult to control the particle size distribution. Furthermore, those distribution number of settings of a conventional crushed material supply nozzle injection nozzle is odd, after forming the swirl flow at an even number of milling nozzle, swirl pulverized solid-gas mixed phase flow with a single crushed material supply nozzle Since it was pushed into the room, there was a problem that the swirling flow was easily segregated due to the multiphase flow pushed later, and the amount of high-pressure gas in the crushing material supply nozzle and the injection nozzle had to be set, and the operation The control is complicated and lacks in operability, and the number of nozzles is odd, so that segregation is likely to occur and the pulverization efficiency and classification efficiency are lacking. In addition, since each injection nozzle has only one injection port, the swirl and crushing chamber is manufactured by analyzing and analyzing the streamline of the swirling flow as one line two-dimensionally and forming the swirl and crushing chamber. In the upper part (top liner part) and the lower part (bottom liner part), the flow velocity is low, and the residence time of large particles in the rotating and crushing chamber is long, and the upper and lower liner parts are abraded accordingly. Had a point. In addition, since the adjustment of the particle size of the fine powder is performed only by changing the pressure and the air volume of the jet flow in all types, the segregation of the swirling flow and the fine powder to the inner wall of the swirling pulverizing chamber etc. are performed depending on the characteristics of the crushing material. Compression is easy to occur, and there is a drawback that the liner parts of the ring liner and top and bottom liner of the turning and crushing chamber are severely worn,
There was a problem that stable continuous production was impossible.

The present invention has been made to solve the above-mentioned conventional problems, and it is possible to obtain a fine powder having a narrow particle size distribution at a very high efficiency by enabling high pulverization efficiency and classification rate without occurrence of segregation. The flow velocity distribution of the multiphase flow in the chamber can be made uniform, reducing the dependence of the crushing material on the rotating crushing chamber wall surface, increasing the reliance on crushing material collision, preventing abrasion of the wall surface and reducing the pressure of fine powder. It is an object of the present invention to provide a jet mill which is extremely small, shortens the residence time in the swirl chamber, significantly improves the pulverization processing capacity, and enables long-time continuous processing.

[0005]

A jet mill according to a first aspect of the present invention is a jet mill of a horizontal swirling flow type, in which a jet mill is formed on a hollow disk-shaped swirling and pulverizing chamber and a side wall of the swirling and pulverizing chamber. The m high pressure gas having a mouth inclined toward the peripheral wall side to inject a high-pressure gas to form a swirling flow, and the high-pressure gas accompanies the high-pressure gas with m pieces of pulverizing nozzles disposed on the side wall of the swirling and pulverizing chamber. N venturi nozzles to be introduced (where m + n = a, a
Is an integer, m> n), a solid-gas mixing chamber formed upstream of the Venturi nozzle, a crushing material supply unit connected to the solid-gas mixing chamber, and the Venturi nozzle in the solid-gas mixing chamber. A push nozzle disposed coaxially, an outlet for discharging fine powder disposed above a central portion of the revolving crushing chamber, and a center disposed at the center of the lower surface of the revolving crushing chamber
And a pole , wherein the venturi nozzle is
Negative pressure between the venturi nozzle throat and inlet
A negative pressure generating section, wherein a length g of the negative pressure generating section is
It has a configuration that is 2 to 4.2 times the inlet diameter D of the section .
As a result, the venturi nozzle throat and bench
Negative pressure generating part between the inlet part (upstream side)
With the provision, the crushed material is
Flow into the venturi nozzle without leakage
Of stable and high-speed supply to the revolving grinding chamber
Having. In addition, the length g of the negative pressure generating section is
Since the diameter D is 2 to 4.2 times, the venturi nozzle
If the swirling flow hardly occurs at the inlet and the suction negative pressure is small,
And it is difficult to generate pressure bonding at the negative pressure generating part
Has an action. Here, the negative pressure generating part is formed between the throat part and the introduction part of the venturi nozzle. Negative pressure generation
The inclination angle theta ₂ of the inclination angle theta ₁ and the discharge portion of the parts are with respect to the axial line of the venturi _{nozzle, 0.5 ° ≦ θ 1 ≦ θ} 2, represented by preferably _{0.7 ° ≦ θ 1 ≦ θ 2} . Note that θ ₂ is 2.
It is formed at 5 ° to 6 °, preferably 3 ° to 5 °. θ ₁
Becomes smaller than 0.7 °, the amount of negative pressure generated is small and the suction tends to be insufficient, and as θ ₂ becomes larger than 5 °, the amount of negative pressure generated is also small and the suction tends to be insufficient. Appears, so neither is preferred. As θ ₂ becomes smaller than 3 °, a pressure loss occurs at the inlet of the introduction part, so that the function of the negative pressure generating part cannot be obtained and the pulverizing ability tends to be reduced. Any tendency is found to decrease the flow rate of the multiphase flow and decrease the pulverizing ability, so that both are not preferred. The length g of the negative pressure generating portion is 2 to 4.2 times the inlet diameter D of the negative pressure generating portion,
Preferably, it is formed 2.2 to 3.8 times. As the length g of the negative pressure generating portion is reduced from 2.2 times than the inlet diameter D of the negative pressure generating portion generates a swirl flow in the introduction of the venturi nozzle, appeared a tendency of reducing the negative pressure of the suction However, as the ratio becomes larger than 3.8 times, the tendency that the crimping at the negative pressure generating portion is easily generated appears.
Neither is preferred. Distance l (mm) between the Venturi nozzle introduction part of the gas-solid mixing chamber and the discharge side of the pushing nozzle
Is represented by l = (D / d) × k (mm) , and the k value is k = 7 to 12 (mm), preferably k = 8 to 10 (mm)
(Where D is the inlet diameter of the negative pressure generating section , d is the diameter of the ejection side of the pushing nozzle). This allows the venturi nozzle and the pulverizing nozzle to rise at the same air pressure at the same time, allows smooth intake of the crushing material regardless of the type of crushing material, and enables continuous operation. Here, the distance l (mm) between the venturi nozzle and the pushing nozzle is the distance between the entrance of the introduction part of the venturi nozzle and the tip of the pushing nozzle, and is (D / d) x k (mm) = l (mm ) ) , K = 7 ~
12 (mm) preferably is represented by the relationship of 8 to 10 (mm), as the k is less than 8 (mm), tended to force Komu blowing the crushed material is reduced, and k is 10 (m
m), the tendency of the high-speed jet flow from the indentation nozzle to completely escape from the Venturi nozzle, and a tendency to cause pressure loss was observed. Therefore, it was obtained from the analysis and the experimental results of the jet mill that neither was preferable. The swirling crushing chamber and grinding nozzle or pushing nozzles and venturi nozzle materials, iron-based, aluminum-based, copper-based, and the like that are combined with metals and alloys or ceramics titanium-based, in particular hard alloy wear Worn It is preferable from the aspect of properties. As the high-pressure gas, an inert gas such as air, nitrogen, or argon is used in accordance with the type of crushing material and crushing conditions.

A jet mill according to claim 2 of the present invention.
The invention according to claim 1, wherein the throat portion
The length h is 2.25 to 5 times the diameter e of the throat portion.
It has a certain configuration. With this configuration, according to the first aspect,
In addition to the effect obtained, the shadow of the discharge part of the venturi nozzle
It is difficult to reduce the negative pressure without being affected, and in the throat part
Has the effect that it is difficult for the pressure bonding to occur. Where the slot
The length h of the port portion is 2.25 to 5 times the diameter e of the throat portion.
It is formed by a factor of, preferably 3 to 4 times. Throat head
The height h becomes smaller than three times the diameter e of the throat.
And the negative pressure tends to decrease under the influence of the discharge section.
It appears, and as it gets larger than 4 times,
Tends to crimp easily.
This is not preferred either.

A jet mill according to a third aspect of the present invention is the jet mill according to the first or second aspect, wherein the total number m + n of the crushing nozzle and the venturi nozzle is an even number, and 5 ≦ m ≦ 15; It has a configuration in which 1 ≦ n ≦ 5 . Thus, in addition to the effects obtained by claim 1 or 2, since the nozzles are arranged at equal intervals on the peripheral wall of the revolving pulverizing chamber without being unevenly distributed as in the prior art, the system is separated from the pulverizing nozzle and the Venturi nozzle. Can be synchronized by balancing the pressure injected to the blast, preventing the occurrence of swirl flow segregation and consequently making it easier to operate. , The dependence on the collision between particles can be increased, and the wear of the liner in the revolving grinding chamber can be significantly suppressed. Furthermore, since the crushing material is prevented from being segregated in the rotating crushing chamber, the crushing efficiency can be increased and the classification rate can be increased. Here, the number m of grinding nozzles and the number of Venturi nozzles
n is 5 ≦ m ≦ 15, 1 ≦ n ≦ 5, preferably 5 ≦ m ≦ 1
4, 1 ≦ n ≦ 2. As the number of pulverizing nozzles becomes smaller than 5, the control of the shape and speed of the swirling flow tends to be lacking. As the number of pulverized nozzles becomes larger than 14, the structure of the jet mill becomes complicated and the control of the solid-gas multiphase flow is performed. However, there is a tendency that the process becomes difficult.

According to a fourth aspect of the present invention, there is provided the jet mill according to any one of the first to third aspects, wherein each of the pulverizing nozzles is vertically arranged in p stages (where,
≦ p ≦ 5) and / or q rows on the left and right (however, 1 ≦ q ≦ 5)
Is provided. Thereby, in addition to the action obtained by any one of claims 1 to 3,
In addition to being able to three-dimensionally control the swirling flow of the pulverizing zone and the classification zone in the orbiting pulverizing chamber, it is possible to round the shape of the particles, narrow the particle size distribution, and freely control the range of the particle size distribution. Has the effect of being able to. Since each of the pulverizing nozzles has a multistage and / or multirow injection unit, streamlines in the revolving pulverization chamber are three-dimensionally captured as a multistage layer, and a speed difference in a height direction in the mill is reduced. By making the particle size smaller, the residence time of the particles in the mill is shortened, and the pulverizing treatment capacity can be improved. Here, the number of stages (p) of the injection unit of the pulverizing nozzle is 2 ≦ p ≦ 5,
Preferably, p = 3 is used. If the number of stages p is less than 2, the flow velocity of the swirling flow in the vertical direction in the swirling and crushing chamber tends to be lower than that in the center, and p is more than 4 or the number of rows (q) of the injection unit is 5 It is not preferable because the swirling flow tends to be difficult to balance as it goes over the row, and it becomes difficult to control the swirling flow three-dimensionally.

A jet mill according to a fifth aspect of the present invention is the jet mill according to any one of the first to fourth aspects, wherein each of the rows and / or the orifices of each stage of the injecting section is provided. One or more of the diameter and / or the injection angle of the injection unit is differently formed. Thereby, in addition to the effect obtained by any one of claims 1 to 4,
Since the diameter of the injection port of each injection unit differs by one or more in each stage of the pulverizing nozzle, it is possible to control the shape and speed of the three-dimensional pulverizing swirling flow having a horizontal plane and a height. 3 solid-gas swirling flow
By dimensional control, the optimal swirl flow can be formed according to various types of crushing materials with different physical properties, preventing particle size adjustment and compaction of fine powder, and preventing segregation, preventing wear of the liner part Has the effect of being able to In addition, since one or more of the injection angles of each row of the crushing nozzles are different, the collision dependency of the crushing materials in the vortex flow can be improved, and the optimum vortex flow can be adjusted according to various crushing materials having different physical properties. Can be formed. The diameter and injection angle of each row of crushing nozzles and each stage of injection ports can be changed to the injection port diameter and injection angle according to the crushing material by closing the upstream side with a plug etc. For those with heavy specific gravity, increase the air volume by increasing the diameter of the lower injection port, and by increasing the diameter of the upper injection port when the specific gravity of coke, carbon, toner, etc. for electrodes is small. This has the effect of increasing the frequency of crushing material collision and obtaining a fine powder having a narrow particle size distribution in a short time. Since the injection angle can be changed in each row simply by replacing the grinding nozzle, the swirl flow in the swirl mill can be controlled for each crushing material having different physical properties, and a vortex flow suitable for each crushing material can be formed. It has the action of: here,
By changing the injection angle of each row injection section of the crushing nozzle in the range of 20 ° to 80 ° by replacing the crushing nozzle, the collision dependency of the crushing materials in the swirling flow is adjusted. The diameter of the injection port in each row is 0.3 q _G ≤, where q _p is the air volume of the pushing nozzle and q _G is the air volume of one pulverizing nozzle.
_Let q _p ≦ 2.1q _G. Here, as the q _p is less than 0.3Q _G venturi - tendency suction becomes weak negative pressure generation is reduced crushed material occurs in the nozzle, or q _p is greater than 2.1Q _G However, any tendency to disturb the swirling flow in the jet mill is observed, so that any of them is not preferable. As the injection angle of each row injection unit of the pulverizing nozzle becomes smaller than 20 °, the speed of the pulverizing swirling flow decreases, the pulverizing material segregates in the pulverizing chamber, and the pulverizing efficiency tends to decrease. As it gets bigger,
Any tendency is observed that the wear of the ring liner in the revolving and crushing chamber is increased, and therefore, neither is preferable. In addition, in order to make the crushing nozzle universal, the injection angle of the injection section in each row is 22.5 ° (a crushing material that is easily segregated or a crushing material that is difficult to disperse) and 45 ° (a liner portion having a large hardness is large). By combining the injection angles of 67.5 ° (crushing material having pressure-bonding properties) and 67.5 ° (crushing material having pressure-bonding properties), crushing can be efficiently performed from a crushing material having a large specific gravity to a crushing material having a small specific gravity.

According to a sixth aspect of the present invention, in the jet mill according to the fourth or fifth aspect, the jetting portion of the crushing nozzle has a plug insertion hole formed on an upstream side. . Thereby, in addition to the effect obtained by any one of the fourth and fifth aspects, the present invention has an effect that the optimum crushing conditions according to the crushing material can be obtained only by inserting the plug into the plug insertion hole. . Here, a plug made of metal or synthetic resin can be used as the plug inserted into the plug insertion hole.

According to a seventh aspect of the present invention, in the jet mill according to any one of the first to sixth aspects, the apex of the center pole and the lower end surface of the outlet are centered in the height direction of the revolving grinding chamber. It has a configuration on the line. Accordingly, in addition to the effect obtained by any one of the first to sixth aspects, a configuration is formed in which the center pole on the upper surface of the turning and crushing chamber and the outlet on the lower surface of the turning and crushing chamber are on the center line of the turning and crushing chamber. This makes it possible to clearly separate the classification zone and the crushing zone in the whirl crushing chamber. Fine powder having a predetermined size and a narrow particle size distribution is discharged from the outlet at the top of the whirl grinding chamber, and the coarse powder is subjected to high-speed jet flow. The high-speed jet stream has the effect of improving the collision dependency of the raw materials in the high-speed jet stream. Here, examples of the material of the outlet and the center pole include a compound of an iron-based, aluminum-based, copper-based, and titanium-based metal or alloy or ceramics, and a hard alloy is particularly preferable in terms of abrasion resistance.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 Regarding a jet mill according to Embodiment 1 of the present invention,
This will be described below with reference to the drawings. 1 is a cross-sectional view of a main part of a jet mill according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional view of a main part along line II of FIG. 1, and FIG. FIG. 4 is a cross-sectional view of a main part of a solid-gas mixing chamber of the jet mill, and FIG. 4 is a cross-sectional view of a main part of a venturi nozzle of the jet mill according to Embodiment 1 of the present invention. FIG.
Wherein 1 is the jet mill according to the first embodiment,
Is a rotary disk-shaped revolving pulverizing chamber, 3 is a pulverizing nozzle disposed in the revolving pulverizing chamber 2 at equal intervals, 4 is a Venturi nozzle disposed in the revolving pulverizing chamber 2 and 5 is a Venturi A pushing nozzle disposed coaxially with the venturi nozzle 5 via a solid-gas mixing chamber 8 on the upstream side of the nozzle 4, 6 is a main body casing, 7 is a ring liner of the revolving crushing chamber 2, 8
Is a solid-gas mixing chamber, 9 and 10 are a top liner and a bottom liner arranged above and below the revolving and crushing chamber 2, and 11 is a substantially conical upper part which is detachably arranged at the center of the bottom liner 10. The center pole 12 has an outlet formed coaxially with the center pole 11 and detachably attached to the top liner 9, a crushing material supply unit 13 connected to the solid-gas mixing chamber 8, and a sleeve 14 a. A high-pressure header pipe, 15a a high-pressure header pipe, 15a a high-pressure gas pipe for supplying high-pressure gas from the high-pressure header pipe 15 to the pulverizing nozzle 3 and the pushing nozzle 5, 16
Is a pressure adjusting valve for adjusting the pressure of the high pressure gas pipe 15a.

In FIG. 2, α is the injection angle of the Venturi nozzle, and γ is the injection angle of the injection section of the pulverizing nozzle.
α is adjusted to 20 ° to 70 °, preferably 30 ° to 50 °. As the angle becomes smaller than 30 °, there is a tendency that the suction of the multi-phase flow is sucked and the swirling flow is disturbed, and as the angle becomes larger than 50 °, a tendency that the liner portion is liable to be pressed or worn appears. Neither is preferred. γ varies depending on the number of grinding nozzles and the type of crushing material. In FIG. 3, D is the Venturi nozzle 4
Inlet diameter of the negative pressure generating portion Z _2, d is the diameter out of pushing the nozzle 5,
l the introductory Z ₁ and pushing the nozzle 5 of the venturi nozzle 4
Is the distance from the ejection side of the camera. Solid-gas distance l between the discharge end of the inlet portion Z ₁ and pushing the nozzle 5 of the venturi nozzle 4 of the mixing chamber 8, l = (D / d) pushing the nozzle so as to satisfy the equation × k (mm) 5 The position is determined. Where k
The value is a value obtained by analysis and experiment and k = 7 to 12 (m
m) Preferably, a value of 8 to 10 (mm) is employed.

In FIG. 4, θ ₁ is a Venturi nozzle
The inclination angle of the negative pressure generating portion Z ₂ relative to the axis 4, the inclination angle of the discharge portion Z ₄ of theta ₂ is Venturi nozzle 4, theta ₃ the inclination angle of the introduction portion Z ₁ of the venturi nozzle 4, Z ₁ is Venturi nozzle 4 introducing part of the upstream side of the larger flared solid-gas mixed phase flow, Z ₂ is the negative pressure generating portion formed gently inclined to the axis from the inlet portion Z ₁ end, Z ₃ is substantially parallel to the axis throat portion formed in, Z ₄ denotes a discharge portion that is expanded from the rear of the throat portion Z _3, e is the diameter of the throat portion Z _3, h is the throat portion length of Z _3, g is a negative pressure generating unit Z ₂ in length. The inclination angle theta ₂ of the outlet of the inclination angle theta ₁ and the throat portion Z ₃ of the negative pressure generating portion Z ₂ is the axis of the venturi nozzle,
0.5 ° ≦ θ ₁ ≦ θ ₂ , preferably 0.7 ° ≦ θ ₁ ≦ θ ₂
It is formed with. Note that θ ₂ is formed at 2.5 ° to 6 °, preferably 3 ° to 5 °. The length g of the negative pressure generating portion Z ₂ is the negative pressure generating section Z ₂ of the Venturi nozzle 2 to 4.2 times the inlet diameter D, preferably from 2.2 to 3.8 times, the throat portion Z ₃ 2.25 length h is the diameter e of the throat portion Z ₃
It is formed up to 5 times, preferably 3 to 4 times.

The operation of the jet mill of the first embodiment configured as described above will be described below. By simply opening one pressure regulating valve 16, high-pressure gas is supplied to the pulverizing nozzle 3 and the pushing nozzle 5 at the same pressure. The crushing material is supplied from the crushing material supply unit 13, and the crushing material and the air are mixed in the solid-gas mixing chamber 8 by the high-speed jet flow injected from the pushing nozzle 5. The distance l (mm) between the venturi nozzle 4 and the pushing nozzle 5 is (D / d) × k (mm) = 1
(Mm) , k = 7 to 12 (mm), preferably 8 to 10 (m
By satisfying the relationship of m) , there is no pressure loss between the swirling and crushing chamber 5 and the outlet of the Venturi nozzle 4, so that the multiphase flow from the Venturi nozzle 4 is introduced from the Venturi nozzle 4 to the orbiting and crushing chamber 2 at a stable and high speed. . Grinding nozzle 3
, A swirling flow is generated in the swirling crushing chamber 2 by the high-speed jet flow, and a crushing zone is formed on the outer peripheral side of the swirling crushing chamber 2,
A classification zone is formed at the center side of the rotary crushing chamber 2. The crushing materials collide with each other by the high-speed jet and the swirling flow, and finely crush the crushing materials. The fine powder classified in the classification zone is swirled and crushed in chamber 2.
Is discharged from the outlet 12 through the fine powder discharge port 14, and the coarse powder is swirled to the outer periphery by the centrifugal force generated by the swirl, and the coarse powders collide with each other and are repeatedly crushed. Venturi - by the negative pressure generating portion Z ₂ of the nozzle 4, a solid-gas mixed phase flow introduced from the introduction section Z ₁ is injected into the swirling crushing chamber 2 is accelerated flow rate. Also, push nozzle
5 and introducing part Z ₁ of the venturi nozzle 4 with keeping a predetermined distance, so to inject該混phase flow to swirl grinding chamber 2 without impairing the air volume and wind pressure pushing the nozzle 5 by providing a negative pressure generating portion Z ₂ Thus, a controlled swirl flow can be obtained without breaking the balance of the swirl flow.

According to the first embodiment as described above, it is possible to realize smoothly a solid-gas mixed flow venturi nozzle, to enable the results classification index generation is higher pulverization efficiency without causing segregation grains Fine powder with a narrow diameter distribution can be obtained with extremely high efficiency, and the flow rate distribution of the multiphase flow in the swirling and crushing chamber can be made uniform. Can be provided.

Embodiment 2 A jet mill according to Embodiment 2 of the present invention will be described.
This will be described below with reference to the drawings. 5 is a cross-sectional view of a main part of a jet mill according to Embodiment 2 of the present invention, FIG. 6 is a cross-sectional view of a main part along line II-II of FIG. 5, and FIG. FIG. 7 is a rear perspective view of the pulverizing nozzle according to the second embodiment;
FIG. 7B is a bottom view of the crushing nozzle, and FIG.
FIG. 3B is a sectional view of a main part taken along line III-III of FIG. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In FIG. 5, reference numeral 30 denotes a jet mill according to the second embodiment, 31 denotes a composite injection nozzle in which three injection units are formed in three stages in the vertical direction and three columns in the left and right directions, and the composite injection nozzles 31 are equally spaced in the revolving and crushing chamber 2. 7 are arranged. 32, 3
Numerals 3 and 34 denote injection units formed in the upper, middle and lower stages of the composite injection nozzle 31, respectively, and numerals 35 and 36 denote center poles and outlets. In FIG. 6, 37 indicates that the injection angle β is 67.
The injection port of the first row of crushing nozzles formed at 5 °, 38 is the injection port of the second row of crushing nozzles formed at an injection angle γ of 45 °, and 39 is the injection angle of δ of 22.5 °. The injection port α of the crushing nozzle in the third row is the injection angle of the Venturi nozzle. In FIG. 7, reference numeral 40 denotes an injection portion of the composite injection nozzle 31, and reference numeral 41 denotes an expanded portion formed at the base of the injection portion 40 of the composite injection nozzle 31, into which a plug 42 is inserted according to the type of crushing material and processing conditions. 42 is a plug insertion hole.
Is a plug.

The operation of the jet mill according to the second embodiment configured as described above will be described below.
Seven compound crushing nozzles 31 are installed at predetermined positions and at angles in the ring liner 7 of the rotary crushing chamber 2, and one compound crushing nozzle 31 is formed with a total of nine injection ports in three rows and three stages. ing. The upper injection unit 32 controls the upper layer of the jet mill 30 in the height direction, the middle injection unit 33 controls the middle layer of the jet mill 30 in the height direction, and the lower injection unit 34 controls the jet mill 30. By controlling the lower layer in the height direction, the shape and speed of the pulverizing swirling flow can be controlled three-dimensionally. By adjusting the injection angle β of the first row injection port 37 of the composite crushing nozzle 31 in the range of 50 ° to 80 °, the crushing material and the ring liner 7 of the revolving crushing chamber 2 are adjusted.
Can be controlled. The injection angle γ of the second row injection port 38 of the composite crushing nozzle 31 is 30 ° to 6 °.
By adjusting the range of 0 °, it is possible to control the collision dependency of the crushing materials in the swirling flow. The injection angle δ of the third row injection port 39 of the composite crushing nozzle 31 is 20 ° to 50 °.
By adjusting the range of °, crushed material jet mill 3
The dwell time within 0 can be controlled. A high-speed jet flow from each injection port of the composite pulverizing nozzle 31 generates a swirl flow in the swirl-pulverizing chamber 2, and forms a pulverizing zone on the inner peripheral side of the swirl-pulverizing chamber 2. Is formed. Raw materials collide with each other by the high-speed jet and the swirling flow, and the crushing material is crushed. The fine powder classified in the classification zone is discharged from the outlet 36 of the revolving crushing chamber 2 through the fine powder discharge port 14a, and the coarse powder is revolved to the outer periphery by the centrifugal force generated by the revolving, and the crushing materials collide with each other to repeatedly crush. Do. In addition, by inserting the plug 42 into the insertion hole 40, the injection units 32, 33, 34
By controlling the injection angle and the number of injection ports, a swirling flow suitable for various powders can be formed.

Next, the state of the swirling flow when the injection sections of the pulverizing nozzles are arranged in one line and the diameter of the injection port of each injection section is changed will be described with reference to a schematic diagram. FIG. 8 is a schematic diagram showing the relationship between the diameter of one row of injection ports of the composite injection nozzle and the swirling flow. FIG.
It can be seen that the swirl flow corresponding to the crushing material can be obtained by changing the diameter of the one row of injection ports of the crushing nozzle 31 in each stage. In the case of a, since a swirling flow can be uniformly formed in all layers, various pulverizers can be pulverized with high efficiency. b
In the case of (1), a large amount of air can be obtained in the upper layer, so that it is suitable for a pulverizer having a low specific gravity such as toner and carbon. In the case of c,
Since a large amount of air flows in the lower layer, it is suitable for crushing materials having a high specific gravity, such as fine ceramics. The case of d is suitable for a pulverizer for mixing several kinds of powders having different specific gravities. The case of e is suitable for pulverizing various powders with small power. In the case of f, the specific gravity is large and it is particularly suitable for a pulverizer of powder having poor dispersibility. In the case of g, the specific gravity is light and suitable for a crushable powder which is fragile. Here, as the caliber ratio, the large / medium / small caliber ratio is a small caliber a, the medium caliber b, and the large caliber c.
The confirmation test showed that b: c = a: 1.5-3a: 3a-6a.

Next, a modification of the second embodiment will be described with reference to the drawings. FIG. 9A is a cross-sectional view of a main part of the main body of the assembled crushing nozzle according to the second embodiment of the present invention. FIG. 9B is a bottom view of the main body of the assembled crushing nozzle.
FIG. 9 (c) is a front view of the main body of the assembled crushing nozzle, and FIG. 9 (d) is a cross-sectional view of the main part of the insertion type injection unit of the assembled crushing nozzle. In FIG. 9, 50 is an assembling and crushing nozzle provided with an insertion hole of an insertion type injection unit in which each row is provided at a different angle in the axial direction of the main body in a modification of the second embodiment of the present invention. Assembling and grinding nozzle body, 5
Reference numerals 2, 53, and 54 denote square insertion holes into which the first, second, and third rows of insertable injection units are inserted, respectively. The insertion holes 52 and 54 are assembled in the revolving pulverizing chamber 2 and the pulverizing nozzle 5
0, a predetermined injection angle (ex. 22.5)
°, 67.5 °) is obtained by being inclined with respect to the axial direction of the main body 51. 52a, 53a, 54
a is an insertion type injection unit inserted into the insertion holes 52, 53, 54 of each row, and 42 is inserted into the plug insertion holes formed on the upstream side of the insertion holes 52, 53, 54 as necessary. Plug. The operation of the assembling and crushing nozzle according to the modification of the second embodiment configured as described above will be described below. Each row 52, 5 of the assembly crushing nozzle 50
3, 54 and / or the diameter and / or angle of the injection port of each of the stages 32, 33, 34 are appropriately optimized for the insertion type injection sections 52a, 53a, 54a according to the type of crushing material and the crushing conditions. It can be obtained only by selecting and inserting, whereby an optimum swirling flow according to the crushing material can be obtained. Since the insertion hole is formed in a square shape, even when high-pressure gas is introduced, the injection portion does not come off, and the predetermined position and angle can be maintained. The main body 5 is inserted into the insertion holes 52 and 54 so that a predetermined injection angle can be obtained.
1 was bored inclining with respect to the axial direction.
54 may be formed in parallel with the axial direction of the main body 51, and the injection holes of the insertable injection sections 52 a and 54 a may be formed to be inclined at a predetermined angle with respect to the axial direction of the main body 51.

As described above, according to the second embodiment, in addition to the effects obtained in the first embodiment, the injection angle α of the venturi nozzle and the injection angles β, γ, and δ of the injection unit of the composite crushing nozzle are adjusted. By providing one or more rows and one or more stages of injection ports in one compound grinding nozzle, it is possible to three-dimensionally control the swirling flow of the pulverizing zone and the classification zone in the swirling and pulverizing chamber, and adjust the particle size and fine powder. Compression, preventing segregation of crushing material in the revolving grinding chamber, minimizing wear of the ring, top and bottom liners, improving grinding efficiency, rounding the shape of the particles, and particle size distribution. And a horizontal swirling flow type jet mill capable of controlling the particle size distribution range freely can be provided. In the above description, an example has been described in which seven pulverizing nozzles are provided at predetermined angles except for the venturi nozzle at positions that divide the periphery of the revolving pulverizing chamber 2 into eight equal parts. The same can also be implemented for those that have done this. In addition, although the number of columns is described as three, one or more columns may be used.

[0022]

Next, the present invention will be specifically described based on examples. (Example 1) Using the jet mill according to Embodiment 1, V ₂ O ₅
A catalyst pulverization test was performed. Revolving crushing chamber is 400m inside diameter
m and height adjusted to 70 mm were used. The crushing nozzles were provided at each position where seven injection nozzles having a diameter of 3.4 mm and one venturi nozzle were used and the peripheral wall of the revolving crushing chamber was divided into eight equal parts. (2) Crushing material: V ₂ O ₅ catalyst, X ₅₀ = 15 μm. (3) Pulverization conditions: pneumatic pressure of the indentation nozzle and pulverization nozzle, 7 kgf / cm ² ; introduction amount of pulverizer, 60 kg / hr; continuous operation 72 hr. A grinding test of the V ₂ O ₅ catalyst was performed under the above conditions. After the operation was completed, the jet mill was disassembled, and the V ₂ O ₅ catalyst pressure-bonded layer of the ring liner in the turning and crushing chamber was measured. As a result, the thickness of the maximum pressure bonding layer was 3.7 mm.

(Comparative Example 1) In Comparative Example 1, a pulverizing test of a V ₂ O ₅ catalyst was performed using a conventional jet mill. (1) Size and structure of jet mill: The revolving and crushing chamber used was the same size as in Example 1. The same pulverizing nozzle and Venturi nozzle as in Example 1 were used. 8 crushing nozzles rotate 8 crushing chambers
It is arranged at each equally divided position, and one between two grinding nozzles
It is also the case that a plurality of Venturi nozzles are provided. (2) Crushing material: The same material as in Example 1 was used. (3) Grinding conditions: The grinding was performed under the same conditions as in Example 1. After the operation is completed, the jet mill is disassembled and the V ₂ O ₅
The catalyst pressure-bonded layer was measured. As a result, the thickness of the maximum pressure bonding layer was 12 mm. As is apparent from the thickness value of the maximum compression layer of Example 1 and Comparative Example 1, the jet mill is compared with the conventional example 1, the jet mill the ring liner after operating 72 hours V ₂ O ₅ It was found that the thickness of the catalyst maximum pressure bonding layer was only 31% of Comparative Example 1. As described above, according to the first example of the first embodiment, it is found that the high-speed jets in the turning and crushing chamber collide the crushing materials to improve the crushing efficiency. In addition, the shapes of the particles were all round. This proved that high-quality fine powder was obtained.

Example 2 V ₂ O ₅ was obtained by using the jet mill of the embodiment 2.
A catalyst pulverization test was performed. (1) Size and structure of jet mill: The same rotary milling chamber as in Example 1 was used. The composite pulverizing nozzle used three injection ports (diameter: 2.0 mm) in one row. One venturi nozzle was used and arranged at each position where the peripheral wall of the rotary crushing chamber was divided into eight equal parts. (2) The crushing material and (3) crushing conditions were the same as those in Example 1. For the evaluation, the particle size and particle size of the pulverized fine powder were measured with a laser particle distribution meter. The results are shown in FIG. FIG. 10 is a diagram showing the relationship between the particle size of the pulverized fine powder and the particle size accumulation%.

Comparative Example 2 In Comparative Example 2, the jet mill of Comparative Example 1 was used under the same conditions as in Example 2. Next, evaluation was performed under the same conditions as in Example 2. The results are shown in FIG. As is clear from FIG. 10, the maximum particle size of the pulverized fine powder of Example 2 was 6.0 μm, while that of Comparative Example 2 was 32.0 μm. It was found that the particle size distribution range of Example 2 could be narrowed to 18% of Comparative Example 2. In Example 2, the crushing materials collide with each other by the high-speed jet in the turning crushing chamber, thereby improving the crushing efficiency, and also improving the crushing efficiency without segregating the crushing materials in the turning crushing chamber, and improving the particle size as fine powder precision. This is because the distribution is narrow and the particle size distribution range can be adjusted. Further, it particle diameter X ₅₀ Example 2 against 1.82Myuemu, particle size X ₅₀ of Comparative Example 2 was found to be 3.82μm. 4 of a particle size X ₅₀ has a particle size X ₅₀ of Comparative Example 2 Example 2
Since it is only 7%, it is understood that the particle size distribution of Example 2 is extremely narrow. After the experiment was completed, the jet mill of Example 2 was disassembled and the inside of the revolving pulverizing chamber was checked. On the other hand, in Comparative Example 2, the same crimping as in Comparative Example 1 was observed. From this, it was found that in Example 2, no segregation occurred, and the swirling flow was controlled in a balanced manner.

Example 3 The dependence of the particle size distribution of the crushed material on the pressure of the high-speed jet stream was confirmed using the jet mill in the second embodiment. (1) High speed jet flow pressure 7.5 kgf / cm
² (a) and 4.5 kgf / cm ² (b). (2) Crushing material and introduction amount: Epoxy resin (X ₅₀ = 50 μm) was used, and the introduction amount was each 10 kg / hr. Example 2
The distribution range and particle size distribution were measured in the same manner as described above. The results are shown in FIGS. FIG. 11 is a diagram showing the dependence of the particle size distribution% of the fine powder on the high-speed jet flow pressure of 7.5 kgf / cm ² , and FIG. 12 is the fine powder on the high-speed jet flow pressure of 4.5 kgf / cm ² FIG. 4 is a graph showing the dependence of the particle size distribution% on the particle size. As is clear from FIGS. 11 and 12, the particle size distribution of the fine powder of FIG.
FIG. 12 shows a range of 7.0 μm to 23.3 μm.
It was found to be in the range of 35.0 μm. Further, it was found that the particle size distribution curve hardly changed. This indicates that the size of the particles can be freely changed with a narrow particle size distribution only by changing the pressure of the high-speed jet stream.

[0027]

As described above, according to the jet mill of the present invention, the following excellent effects can be realized. According to the jet mill according to claim 1 of the present invention, (1) the throat portion of the venturi nozzle and the venturi
Equipped with a negative pressure generating section between the nozzle introduction section (upstream side)
As a result, the crushed material is
Therefore, it is sucked into the venturi nozzle without leakage and high speed
And it can supply to a revolving grinding chamber stably. (2) It is difficult for swirl flow to occur at the inlet of the venturi nozzle
Therefore, the negative pressure of suction does not decrease,
Crimping is difficult to generate. According to the jet mill of the second aspect of the present invention, in addition to the effect of the first aspect, (3) the negative pressure is less likely to be reduced without being affected by the discharge portion;
The hardly occurs crimping at the throat portion. According to the jet mill of the third aspect of the present invention, in addition to the effect of any one of the first and second aspects, ( 4 ) each nozzle is provided on the peripheral wall of the revolving and crushing chamber as in the prior art. Since they are arranged at equal intervals without uneven distribution, it is possible to synchronize and balance the pressure injected into the system from the pulverizing nozzle and the venturi nozzle. The operation can be facilitated, the dependence on the wall of the crushed material can be reduced, and the dependence on the collision between the particles can be increased, so that the wear of the liner portion in the turning and crushing chamber can be remarkably suppressed. Furthermore, since the crushing material is prevented from being segregated in the rotating crushing chamber, the crushing efficiency can be increased and the classification rate can be increased. Claim 4 of the present invention
According to the jet mill described in (1), in addition to the effects described in any one of (1) to ( 3 ), ( 5 ) the swirling flow of the pulverizing zone and the classification zone in the swirling pulverizing chamber is three-dimensionally controlled. In addition, the shape of the particles can be rounded, the particle size distribution can be narrowed, and the range of the particle size distribution can be freely controlled. ( 6 ) By having the multi-stage injection unit in the multi-row grinding nozzle, streamlines in the revolving grinding chamber are three-dimensionally captured as a multi-stage layer, and the speed difference in the height direction in the mill is reduced. Thereby, the residence time of the particles in the mill can be shortened, and the processing capacity of the pulverization can be improved. According to the jet mill described in claim 5 of the present invention, in addition to the effects described in any one of claims 1 to 4, ( 7 ) the crushing nozzles are multi-row and the injection angle of each injection unit is Since they are different from each other, it is possible to control the shape and speed of a three-dimensional grinding swirling flow having a horizontal plane and a height. By controlling the solid-gas mixed-phase swirl flow three-dimensionally, an optimum swirl flow can be formed in accordance with various types of crushing materials having different physical properties, thereby preventing particle size adjustment and fine powder compression and segregation. So
Wear of the liner portion can be prevented. ( 8 ) Since at least one of the diameters and / or injection angles of the injection ports of each row of the pulverization nozzles is different, the collision dependency of the pulverizers in the swirling flow can be improved, and various types of pulverization having different physical properties can be achieved. The optimal swirling flow can be formed according to the material. ( 9 ) Since the diameter of each row of injection nozzles of the crushing nozzle can be changed, for those with a high specific gravity such as ceramics, the diameter of the lower injection port is increased to increase the air volume, and the coke for electrode When the specific gravity of carbon, toner, or the like is small, the frequency of collision of the crushing material can be increased by increasing the diameter of the upper injection port, and a fine powder having a narrow particle size distribution can be obtained in a short time. ( 10 ) Since the injection angle can be changed in each row just by replacing the crushing nozzle, the swirl flow in the jet mill can be controlled for each crushing material having different physical properties, and a vortex flow suitable for each crushing material can be formed. can do. Claim 6 of the present invention
According to the jet mill described in (1), in addition to the effect described in any one of (4) and (5) above, ( 11 ) optimum pulverization according to the crushing material only by inserting a plug into the plug insertion hole. Condition can be obtained. According to the jet mill described in claim 7 of the present invention, in addition to the effects described in any one of claims 1 to 6, ( 12 ) the center pole on the upper surface of the revolving crushing chamber and the revolving crushing chamber By forming a configuration in which the outlet on the lower side is on the center line of the orbiting grinding chamber, the classification zone and the grinding zone can be clearly separated in the orbiting grinding chamber. The coarse powder is discharged from the outlet at the upper part of the chamber, and the coarse powder is blown to the outer periphery by the centrifugal force generated by the high-speed jet flow, so that it is possible to improve the collision dependency of the crushing materials in the high-speed jet flow.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a jet mill according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a principal part taken along line II of FIG. 1;

FIG. 3 is a sectional view of a main part of a solid-gas mixing chamber of the jet mill according to the first embodiment of the present invention.

FIG. 4 is a sectional view of a main part of a venturi nozzle of the jet mill according to the first embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a jet mill according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a main part taken along line II-II of FIG. 5;

7A is a rear perspective view of a crushing nozzle according to Embodiment 2 of the present invention. FIG. 7B is a bottom view of the crushing nozzle. FIG. 7C is a cross-sectional view of a main part taken along line III-III in FIG.

FIG. 8 is a schematic diagram showing the relationship between the diameter of a single row of injection ports and the swirling flow of the composite injection nozzle of the present invention.

9A is a sectional view of a main part of the main body of the assembled crushing nozzle according to the second embodiment of the present invention. FIG. 9B is a bottom view of the main body of the assembled crushing nozzle. Sectional view of main part of insertion type injection part of assembled crushing nozzle

FIG. 10 is a graph showing the relationship between the particle size and the particle size cumulative% of the pulverized fine powders of Example 2 and Comparative Example 2 of the present invention.

FIG. 11 is a diagram showing the dependence of the particle size distribution% of fine powder on the high-speed jet flow pressure of 7.5 kgf / cm 2 in Example 3 of the present invention.

FIG. 12 is a diagram showing the dependence of the particle size distribution% of fine powder on the high-speed jet flow pressure of 4.5 kgf / cm 2 in Example 3 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Jet mill in Embodiment 2 Rotating grinding chamber 3 Grinding nozzle 4 Venturi nozzle 5 Push nozzle 6 Main body casing 7 Ring liner 8 Solid-gas mixing chamber 9 Top liner 10 Bottom liner 11 Center pole 12 Outlet 13 Crushing material supply unit 14 Fine powder body outlet 14a sleeve 15 pressure header pipe 15a high-pressure gas pipe 16 pressure regulating valve 30 a jet mill 31 in the second embodiment composite grinding nozzles 32, 33, 34 injection unit 35 center pole 36 outlet 37, 38, 39 injection opening 40 the injection part 41 plug insertion hole 42 plug 50 a modification of the assembly grinding nozzles 51 assembled crushing nozzle body 52, 53, 54 insertion hole 52a of the embodiment 2, 53a, 54a inserted jetting unit theta ₁ slope of the negative pressure generating portion angle θ ₂ ejection Part of the inclination angle theta ₃ venturi inlet portion of the inclination angle Z ₁ venturi inlet portion Z ₂ negative pressure generating unit Z ₃ inlet diameter h throat diameter D negative pressure generating part of the throat portion Z ₄ discharge portion e throat portion of the nozzle of the nozzle Length of the part g Length of the negative pressure generating part d Exit diameter of the pushing nozzle l Distance between the introduction part of the Venturi nozzle and the discharge side of the pushing nozzle α Injection angle of the Venturi nozzle β, γ, δ Injection angle

Claims (7)

(57) [Claims] 1. A jet mill of a horizontal swirling flow type, which jets a high-pressure gas having a hollow disk-shaped swirling and crushing chamber and an injection port disposed on a side wall of the swirling and crushing chamber with an injection port inclined toward a peripheral wall. And a pulverizer disposed on the side wall of the orbital pulverizing chamber and introducing the pulverizer along with the high-pressure gas.
Venturi nozzles (where m + n = a, a is an integer, m> n), a solid-gas mixing chamber formed upstream of the venturi nozzle, and a crushing material supply unit connected to the solid-gas mixing chamber A pushing nozzle disposed coaxially with the Venturi nozzle in the solid-gas mixing chamber, an outlet through which fine powder disposed at an upper part of the center of the revolving crushing chamber is discharged , and Center port located in the center of the lower surface
A venturi nozzle, wherein the venturi nozzle is
A negative pressure generating section is provided between the throat section and the introduction section,
The length g of the pressure generating part is 2 to 2 of the inlet diameter D of the negative pressure generating part.
Jet mill characterized by 4.2 times . 2. The method according to claim 1 , wherein the length h of the throat portion is equal to the length of the throat.
Characterized in that the diameter is 2.25 to 5 times the diameter e of the part
The jet mill according to claim 1. 3. The method according to claim 1, wherein the sum of m + n of the pulverizing nozzle and the venturi nozzle is an even number, and 5 ≦ m ≦ 15, 1 ≦ n ≦ 5. Jet mill. 4. The method according to claim 1, wherein each of the pulverizing nozzles is vertically arranged in p stages (provided that 2 ≦ p ≦ 5) and / or in right and left columns (where 1 ≦ q
2. The injection unit according to claim 1, further comprising:
4. The jet mill according to any one of 1 to 3, wherein 5. The apparatus according to claim 1, wherein one or more of the diameters of the ejection ports and / or the ejection angles of the ejection sections in each row and / or each stage of the ejection section are different.
The jet mill according to any one of Items 1 to 4. 6. The jet mill according to claim 4, wherein the injection portion of the pulverizing nozzle has a plug insertion hole formed on an upstream side. 7. The method according to claim 1, wherein a vertex of the center pole and a lower end surface of the outlet are on a center plane in a height direction of the revolving and crushing chamber.
Jet mill according to the item.