JPH0790177B2 - Airflow type fine crusher - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an air flow for pulverizing solid substances such as pharmaceuticals, agricultural chemicals, foods, chemical products, synthetic resins, metallic materials, and inorganic substances into fine powders having a narrow particle size distribution range of about several tens of μm to about 1 μm. For more details about the type of fine pulverizer,
The present invention relates to an air flow type fine pulverizer suitable for pulverizing low melting point, weak heat, adhesiveness, or abradable substances.

[0002]

2. Description of the Related Art As a conventional device of this kind, for example, (1) Japanese Patent Publication No. 54-13631, (2) Japanese Patent Publication No. 6
No. 2-8215, and (3) Japanese Patent Publication No. 60-184.
The one disclosed in Japanese Patent No. 54 is known. In these devices, the supplied solid matter (hereinafter referred to as crushed material) is crushed by a gas jet, and the powder produced by crushing is sorted by a classifying means in the upper part of the crushing chamber. The fine powder having a particle size of a predetermined size or less is taken out of the apparatus by a transport dust collecting means (not shown), and the remaining coarse powder is returned to the crushing chamber again and repeatedly crushed.

Among these, in the publications (1) and (2),
The crushed material is sent to the crushing chamber by some mechanical transportation means, a gas jet is blown into the powder layer stored in the crushing chamber through a nozzle, and the powder is crushed by collision and friction between the powders. I do. The crushed crushed material is carried to the classification zone by the crushing action and the depressurized air flow, and the coarse powder selected by the forced rotation type classification rotor is shown in Fig. 4; 8; 14 of the above publication (1). The powder is returned to the means for transporting the crushed material as shown in Fig. 1 or is directly returned to the powder bed by gravity as shown in Fig. 15 and JP (2) of Publication (1).

Further, in the above-mentioned publication (3), below the crushed material hopper, the crushed material is sucked by a gas jet flowing from an injector nozzle and then accelerated in an accelerating pipe toward a crushing chamber. On the other hand, the coarse powder selected by the classifying means is sucked by a gas jet flowing from another facing nozzle, is accelerated in another accelerating pipe, and is crushed and conveyed from the opposite side. Collide in the grinding chamber. The crushed material generated by the collision in the accelerating pipe and in the crushing chamber is carried to the classification chamber by the air flow that has a surplus power, and only the fine powder is sent out by the cyclone principle, and the coarse powder is circulated by the air flow and repeatedly crushed Be affected.

[0005]

There are the following problems regarding the supply of crushed material. In the classifying means of the above publications (1) and (2), the static pressure in the crushing chamber becomes equal to or higher than the atmospheric pressure of the outside world due to the fan action of the classifying rotor, which is the classifying means. In order to carry it in, a gas shutoff device such as a double damper or a rotary valve is added as shown in Fig. 5; Fig. 7 of the publication (1), or the description is omitted in the publication (2). However, it is necessary to connect a dust collector after the device and a suction blower to keep the inside of the crushing chamber always below the atmospheric pressure.
If this is not done, there is a drawback that the crushed material is blown out together with the gas from the crushed material hopper.

Further, in the publication (3), the negative pressure generated by the jet of gas ejected from the injector nozzle sucks the crushed material from the crushed material hopper, so that a problem may occur even if the pressure inside the crushing chamber is higher than the atmospheric pressure of the outside. There is no. However, in the accelerating pipe that follows the injector nozzle, the gas jet entrained with the debris passes at a high speed around the sonic velocity,
There is a drawback that the abrasion powder of the vessel wall is mixed in the crushed material, resulting in contamination of the crushed product and wear of the members. Moreover, Fig. 4 of Publication (1);
In Fig. 8; Fig. 14 and Publication (2), a screw is used as a means for transporting the crushed material. However, some crushed material causes stickiness due to the stirring action by the rotation of the screw, so the crushed material It has a drawback that it becomes a binder and restrains the screw shaft in the screw case, so that the crushed material is not transported.

The present invention has been made in view of the above problems of the prior art. The object of the present invention is, even if the static pressure in the crushing chamber slightly exceeds the atmospheric pressure of the outside world. Even without the aid of special additives such as gas barriers, the crushed material does not blow out from the crushed material supply device during work, and even if the crushed material causes caking due to the stirring action, An object of the present invention is to provide an air flow type fine pulverizer capable of supplying a charge.

[0008]

In order to achieve the above object, in the present invention, a crushed material supplied to a crushing chamber through an injector nozzle is crushed by an injector nozzle and a counter nozzle, An airflow in which fine powder of a certain size or less in the pulverized material is classified by the classifying means in the classification chamber above the crushing chamber and taken out of the device, and coarse powder of a certain size or more is returned to the pulverizing chamber by the circulation means and crushing is repeated again. In the fine pulverizer, the counter nozzle is attached to the crushing chamber so as to face the center line of the injector nozzle at an obtuse angle so that the counter nozzle is attached to the crushing chamber, and the tip of the spindle forming the core of the injector nozzle and the counter nozzle Each outer peripheral surface of the tip portion of the needle forming the core is formed into a conical surface that gradually shrinks toward the crushing chamber side, A tubular tubular sheet is externally inserted into the core body of the injector / nozzle and the core body of the counter nozzle, and compressed gas is introduced to the inner surface of each tubular sheet that faces the conical surfaces of the core bodies. From the side toward the crushing chamber, a first conical surface having a cone angle larger than the cone angle of the core body and a second conical surface having a cone angle smaller than the cone angle of the core body or a cylindrical surface are continuous. Formed in the inner surface of each of the tubular sheets and the outer surface of each of the cores, a nod portion serving as a gas passage having a minimum annular cross-sectional area is formed in the middle of the gap to form the core of the injector / nozzle. The spindle to open the crushing chamber side end to carry the crushed material into the crushing chamber from the outside of the crushing chamber is formed hollow so as to communicate with the crushing material hopper provided outside the crushing chamber, and the core of the injector nozzle is Between the hollow spindle and crushed material hopper for forming a stream type pulverizer, wherein a switching means such as a valve that can be communicated or shut off both provided.

In the above structure, the hollow spindle or the needle having the conical surface formed at the tip thereof can be attached to each tubular seat engaged with the tip thereof by screwing or other means so as to be able to move forward and backward. preferable.

[0010]

[Operation] When the compressed gas is supplied to the air flow type fine pulverizer and the crushed material is put into the crushed material hopper and the valve (switching means) connected to the crushed material hopper is opened, the gas blown from the injector nozzle Due to the local negative pressure caused by the jet flow, the crushed material in the crushed material hopper is fluid-transported into the crushed material chamber at a slow speed through the inside of the switching means and the hollow spindle together with the external gas. Subsequently, the crushed material is accelerated by being enclosed in a hollow gas jet blown from the annular passage of the injector nozzle, and collides with the crushed material containing the returned coarse powder accelerated by the gas jet blown from the opposing counter nozzle. When the switching means is "closed", the supply of the crushed material from the crushed material hopper is shut off, and the level of the powder layer in the crushed material chamber is maintained properly.

In addition, regardless of whether the switching means is opened or closed, in the crushing chamber, the gas jet flows through a hollow portion having a relatively low concentration of powder, and around the hollow portion, mainly below the hollow portion. The activity of the powder is divided into a dull powder accumulation layer, and not only the crushed material and the returned coarse powder guided by the air flow of the nozzle, but also the particles in the accumulation layer are continuously drawn out by the suction force of the jet,
The particles are accelerated and crushed by the mutual collision and friction of the powders. The fine powder is carried to the classification chamber along with the air flow depressurized by the pulverization, where only the fine powder having a certain particle size or less is taken out of the device by the classifying means, and the coarse powder having a certain particle size or more is removed. It is returned to the crushing chamber by the circulation means and the crushing is repeated again.

In this case, because of the local negative pressure formed by the jet blown from the injector / nozzle, the switching means is open, and the static pressure inside the crushing chamber is slightly lower than the outside (for example, about 30-40 cm water column). The crushed material does not blow out of the crushed material hopper, even if it is expensive. Moreover, since the switching means is adopted instead of the screw as the means for transporting the crushed material, even in the crushed material that causes stickiness due to the stirring action by the rotation of the screw, the caking of the crushed material seen when the screw is used or Inability to transport is resolved. In addition, since the speed of transportation of the crushed material is slow, the inside of the hollow spindle, which is the transportation passage, is worn away by the wear with the crushed material, and the fine powder generated due to the wear is mixed with the crushed material to contaminate the crushed material. The risk of inviting is extremely low.

[0013]

1 to 7 show an embodiment of the present invention. FIG. 1 shows the main components of the present invention. The crushed material supply device A is attached to the case cover 2a of the crushing case 2, and an injector nozzle B ₁ is formed at one end thereof. The crushing chamber B in which the powder is crushed has a circulation means for transporting the crushed material and returning the coarse powder in the upper part thereof.
A classification chamber C including an air flow preliminary swirl chamber 29 (FIG. 2) is screwed to the vertical surface 1 of the frame by a vertical flange 23a. The classification chamber C is connected to the crushing chamber B by a connecting bolt, and the fine powder outlet 24 of the classification chamber C is connected to a dust collector and a suction blower by a duct (not shown). A counter nozzle B ₂ is provided in the crushing chamber B so as to face the injector nozzle B ₁ , and each of these nozzles B _{1 and} B ₂ is supplied with a gas pressure source ( Compressor).

The crushing case 2 forming the crushing chamber B is shown in FIG.
It consists of a horizontal cylinder with one end open as shown in Fig. 2, and the opening at one end (right side in the figure) is the case cover 2.
It is closed by a and the injector nozzle B ₁ is provided on the outside thereof. The other end (left side in the figure) of the crushing case 2 is a bottom plate 2b having an inclined surface, and the counter nozzle B ₂ is provided in the inclined surface portion of the bottom plate 2b.
Is provided. Center line of the counter-nozzle B ₂ has a center line and the intersection angle α 1 of the injector nozzle B ₁
They intersect at an intersection 2c so as to form an angle of 40 ° to 160 °. The inclined surface of the bottom plate 2b has nozzles B _{1, which} have two intersections 2c _.
It is tilted so that it is approximately equidistant from B ₂ . On the upper side of the intersection 2c, a square tube connected to the classification chamber C is projected from the crushing case 2, and a crushed material transport passage 2d communicating with the air flow preliminary swirl chamber 29 of the classification chamber C is formed.

Further, another square tube juxtaposed with the square tube is projected from the crushing case 2, and from below the double cylinder formed in the classification chamber C toward the vicinity of the tip of the counter nozzle B ₂ . The coarse powder return passage 2e is formed. A branch pipe 2f is projected obliquely upward to a part of the body of the crushing case 2, and a level sensor 4 (for example, a commercially available product such as a vibrating bar type or an electrostatic capacitance type is used) is attached to the cover 3 of the body. , Branch pipe 2
A protective plate 5 for preventing collision with powder scattered from the crushing chamber B side is placed in the inside of f on the center line side of the crushing case 2, and a sensor is provided outside the center of the crushing chamber B divided by the protective plate 5. The detection unit 4a is provided obliquely downward. The level sensor 4 detects the boundary surface between the cavity and the powder deposit layer due to the jet flow in the crushing chamber B, and controls the switching means 16 such as a valve. In FIG. 2, a broken line 6 that crosses the cross section of the crushing case 2 shows an example of a boundary between a hollow portion having a low powder concentration through which a gas jet passes and a deposition layer where the powder is not active.

Referring to FIG. 3, the injector nozzle B
₁ will be explained. The flanged tubular sheet 7 fitted in the central opening of the case cover 2a is fixed by a nozzle case 8 fixed to the case cover 2a by a screw 11. Inside the nozzle case 8, a hollow spindle 9 having a conical surface with a cone angle γ ₂ (≈24 °) formed at the tip is loosely supported by the opening of the nozzle case 8 on the side of the anti-crushing material chamber. Then, the adjustment screw 14a integrated with the elbow 14 screwed to the side opposite to the crushing chamber of the hollow spindle 9 and the arm 12 bolted to the nozzle case 8 are axially positioned. Further, on the inner surface of the tubular sheet 7, a cone angle β (≈90) larger than the cone angle γ _{2 is provided} on the side opposite to the crushing chamber.
°) and a second conical surface having a conical angle γ ₁ (= 16 ° to 18 °) smaller than the conical angle γ _{2 at} the crushing chamber B side are continuously formed. A Laval tube having a "throat" 7a through which a compressed gas passes is formed in a space space between the tip of the hollow spindle 9 and the conical surface.

The back surface of the tubular sheet 7 and the hollow spindle 9
An annular space 8a formed by the central cylindrical surface of the nozzle case 8 and the nozzle case 8 is a retention place of the compressed gas introduced from the screw hole 8b provided on the peripheral surface of the nozzle case 8, and is a nozzle hole (Laval tube). The compressed gas is uniformly blown out from the entire area of. Further, since the adjusting screw 14a is loosely fitted to the arm 12 and fixed by the nut 14b, the hollow spindle 9 can be moved forward and backward with respect to the nozzle case 8 and the two conical surfaces of the tubular sheet 7 can be moved. When the hollow spindle 9 is moved back and forth in order to increase or decrease the cross-sectional area of the “throat” 7a formed by the conical surface at the tip of the hollow spindle 9, the injector nozzle B ₁
The amount of compressed gas blown into the crushing chamber B from can be adjusted.

The crushed material supply device A will be described with reference to FIGS. 3 and 1. The upper opening of the elbow 14 is connected to the powder hopper 13 via a flanged nipple 15, a supply valve (granular material switching means) 16 and a flanged short pipe 17, and is integrated with the hollow spindle 9. . The hollow spindle 9 is advanced and retracted in the direction of the center line of the hollow spindle 9 by an adjusting screw 14a protruding outward from the arm 12 screwed to the elbow 14 and a nut 14b screwing to the adjusting screw 14a, and the nut 14b. Is locked by the arm 12. The crushed material hopper 13 is connected to the short pipe 17 by the coupling 10.

FIGS. 1 and 3 show the case where a commercially available pinch valve is used as the supply valve 16, in which a space formed between the valve box and the rubber sleeve 16a is supplied with air from the air opening 16b. When the rubber sleeve 16a is put in or out, the rubber sleeve 16a expands or returns to its original shape, and the pipeline is closed or opened. As the switching means, a butterfly valve, a ball valve or the like may be adopted instead of the supply valve 16 to open and close the pipeline.

The counter nozzle B ₂ will be described with reference to FIG. The flanged tubular sheet 18 fitted in the hole of the bottom plate 2b of the crushing case 2 is fixed by a nozzle case 19 attached to the bottom plate 2b of the crushing case 2 with a bolt 20. Inside the nozzle case 19, a needle 21 having a conical surface with a cone angle γ ₂ ′ (≈12 °) formed at the tip is provided with a screw 19 of the nozzle case 19 at the base end side.
It is screwed with a and fixed by the lock nut 22.
On the inner surface of the tubular sheet 18, a conical surface having a conical angle β (≈90 °) larger than the conical angle γ ₂ ′ on the side opposite to the crushing chamber, and a cylindrical surface closer to the crushing chamber B are formed continuously. A Laval tube having a "throat" 18a through which a compressed gas passes is formed in a space between the tip of the needle 21 and the conical surface.

An annular space 19c formed by the back surface of the tubular sheet 18, the needle 21 and the inner surface of the nozzle case 19 is filled with compressed gas introduced through a screw hole 19b provided in the peripheral surface of the nozzle case 19. The compressed gas is uniformly blown out from the entire area of the nozzle hole (Laval tube) at the retention place. When the needle 21 screwed into the nozzle case 19 is rotated, the needle 21
Moves back and forth with respect to the nozzle case 19, and the tubular sheet 18
In order to increase or decrease the cross-sectional area of the "throat" 18a formed by the boundary transitioning from the conical surface to the cylindrical surface of the needle 21 and the conical surface at the tip of the needle 21, the needle 21 moves back and forth from the counter nozzle B ₂ to the grinding chamber B. The amount of compressed gas blown in can be adjusted.

The classification chamber C will be described with reference to FIGS. The classification case 23 is screwed to the vertical surface 1 of the frame by a flange 23a provided at one end opening, and the other end is screwed with a classification case cover 25 having a fine powder outlet 24 formed in the center. To be done. Classification case 2
The cylindrical body 3 has a partition wall 23b having a central opening 23c near the vertical surface 1 of the frame. Partition 23b
A part of the bearing case 28 that holds the drive shaft 27 is fitted from the outside into the central opening 23 c of the bearing case 28, and is screwed from the outside to the partition wall 23 b at the portion of the flange 28 a provided at the intermediate portion of the bearing case 28. . A rotary impeller 26 as a classification rotor is attached to a portion of the drive shaft 27 protruding from the bearing case 28 into the classification case 23, and the grinding case 2 is provided below the bearing case 28 in the classification case 23.
Corresponding to the crushed material transport passage 2d is provided with an opening 23d that is deflected with respect to the axis of the classification case 23, and the outer surface of the bearing case 28, the inner surface of the classification case 23, and the partition wall 23b.
And form an airflow preliminary swirl chamber 29 in the annular space.

An inner cylinder 30 that concentrically surrounds the rotary impeller 26 is detachably attached to an extension of the inner surface of the classification case 23 constituting the air flow preliminary swirl chamber 29, and a large diameter classification located outside thereof. A double cylinder is formed together with the large diameter portion 23e of the case 23. Below the large diameter portion 23e of the classification case is a chute shape, and the opening 2 corresponding to the coarse powder return passage 2e is formed.
3f is provided. The classification work is performed between the double cylinder and the rotary impeller 26. One end of the rotary impeller 26 is
Circular bottom surface 2 having boss 26a into which drive shaft 27 is fitted
It has a hollow cylindrical shape that is closed by 6b and the other end is open. On the outer peripheral surface of the rotary impeller 26, a large number of stepped blades 31 arranged in parallel with the axial direction are provided at equal pitches along the circumference, and the outside of the blades 31 is fixed to have a large diameter from the inflow side of the air flow. A cylindrical portion 26d and a small diameter cylindrical portion 26e are provided. In the large-diameter cylindrical portion 26d, an intake passage 26c penetrating the outer peripheral surface of the rotary impeller 26 is formed between the adjacent blades 31, 31, as shown in FIG.

Further, the stepped-down portions 31a of the blades 31 having different steps
Has an inner and outer diameter equal to this and forms a small-diameter cylindrical portion 26e together with the rectangular ring 31b connected to the step-down portion 31a. The circular opening of the rectangular ring 31b corresponds to the fine powder outlet 24 provided in the classification case cover 25. On the inner side of the classification case cover 25, the classification case cover 2
The annular partition plate 32 having the primary gas reservoir 32a connected to the gas introduction hole 25a provided in 5 is screwed,
An axial gap 30a is formed between the inner surface of the partition plate 32 and the open end of the inner cylinder 30 to provide a place where the air stream containing the coarse powder after classification makes a U-turn and is exhausted. In addition, the blade 3 that moves from the large-diameter cylindrical portion 26d to the small-diameter cylindrical portion 26e.
A primary side gap δ ₁ is formed between the inclined surface 31c formed by the outer circumference of No. 1 and the inner peripheral conical surface formed by the partition plate 32.

An annular groove-shaped secondary gas reservoir 33 is formed between the rectangular ring 31b and the inner surface of the partition plate 32 which faces the outer peripheral surface of the rectangular ring 31b. Front and rear partition plate 32 inner peripheral surface and square ring 3
A narrow secondary gap δ ₂ is formed between the outer peripheral surface of 1b. The length of this gap portion is such that the length l ₁ of the secondary gap δ ₂ near the slope 31c of the blade 31 of the rotary impeller 26 is shorter than the length l ₂ of the opposite secondary gap δ ₂ . These gaps δ _1,
The classification chamber C is communicated with the fine powder outlet 24 by δ ₂ and the secondary gas reservoir 33. The primary gas reservoir 32a and the secondary gas reservoir 33 are communicated with each other by a large number of flow passages 34 provided at equal intervals in the circumferential direction, and the gas introduction holes 25a are provided.
The sealing gas flowing in from is uniformly distributed to the secondary gas reservoir 33. During operation, the sealing gas is constantly blown out from the secondary gas reservoir 33 through the primary side gap δ ₁ and the secondary side gap δ ₂ , and is contained in the air flow before classification in the gap between the rotary impeller 26 and the partition plate 32. It prevents the powder from entering and prevents the powder from leaking through the gaps δ _{1 and} δ ₂ to the fine powder outlet 24 side.

The boss 26a of the rotary impeller 26 has a shaft neck 27c of the drive shaft 27 which projects horizontally from the bearing case 28.
Part of the bearing case 28 and the inner ring of the bearing 35a in the bearing case 28 is pressed by the spacer 36 to position the rotary impeller 26, and at the same time, to rotate the rotary blade. The torque required to rotate the vehicle 26 is transmitted. Reference numeral 37 denotes a cover that presses the outer ring of the bearing 35a held in the bearing case 28, and an eave 37e having a width l ₃ that covers the outer periphery of the circular bottom surface 26b of the rotary impeller 26 is provided on the side opposite to the bearing of the cover 37. ing. The cover 37 forms an annular gas reservoir 37c on the side facing the rotary impeller 26. The end face on the center side of the gas reservoir 37c and the end face near the outer periphery are narrow end face gaps δ ₅ and δ ₄ between the circular bottom face 26b of the rotary impeller 26, respectively.
To form. Similarly, the eaves 37e of the cover 37 forms a narrow outer peripheral gap δ ₃ with the rotary impeller 26.

A part of the bearing case 28 is a flange 28.
An L-shaped gas passage 28b passing through a is provided, and an opening end of the gas passage 28b on the cover 37 side is covered by a gas passage 37a provided at a corresponding position of the cover 37.
Of the gas passage 37 while communicating with the gas reservoir 37c of
The outer peripheral surface of the spacer 36 near the bearing 35a and the cover 3 are provided by another gas passage (branch passage) 37b branched from 7a.
7 communicates with the gas reservoir 37d formed by the inner surface of the hole 7. During operation, the compressed gas accumulated in the large gas reservoir 37c moves toward the outside of the rotary impeller 26 from the narrow outer peripheral gap δ ₃ between the rotating rotary impeller 26 and the eaves 37e of the stationary cover 37. Is blown out. Further, a part of the compressed gas passes through the branch passage 37b of the cover 37, passes from the gas reservoir 37d to the narrow gap portion formed by the outer periphery of the spacer 36 and the inner surface of the hole of the cover 37, and further passes through the end face gap δ ₅ . And the gas reservoir 37c, and the rotary impeller 2
The powder (foreign matter) around 6 is prevented from entering the inside of the bearing 35a.

The drive shaft 27 includes the above-mentioned bearing 35a and another bearing 35b fixed to the drive shaft 27 by a nut 38.
Is supported by the bearing case 28 via the drive shaft 27.
A pulley (not shown) is keyed to the shaft neck 27d on the outer side of the shaft neck, and the torque required for the rotation of the drive shaft 27 is transmitted via the belt by the pulley fixed to the motor shaft.

Next, the operation of the apparatus will be described. 1) Gas reservoir 37 for bearing 35a of drive shaft 27 that rotates rotary impeller 26 from the compressed gas source for sealing gas
c, 37d and the gas pool 3 for the gap between the inner peripheral surface of the partition plate 32 of the classification chamber C and the rectangular ring 31b of the rotary impeller 26.
2a, 33 to protect the bearing 35a, and the classification chamber C
Measures are taken to prevent the coarse powder from leaking from the outlet to the fine powder outlet 24. 2) The rotary impeller 26 is accelerated to a predetermined rotation speed for operation. 3) Activate the suction blower to reduce the pressure inside the crushing chamber B. 4) Inject the compressed gas adjusted to the pressure set by the pressure regulator to the injector nozzle B ₁ and the counter nozzle B ₂ . 5) Keep the crushed material supply valve 16 in the "open" state. 6) Inside the grinding chamber B, the injector / nozzle B ₁
The powder in the accumulated layer in the crushing chamber B, which remains due to the previous work, is blown out from both nozzles B _{1 and} B ₂ by being attracted to the gas jet ejected from The jets are sucked and accelerated to start the crushing work. At this time, the static pressure inside the crushing chamber B becomes a steady value (higher than the outside). 7) At the same time, the finely ground pulverized product is conveyed to the classification chamber C by the air flow depressurized by the pulverization, and is classified into fine powder and coarse powder by the rotary impeller 26, and the fine powder is put on the air flow by the suction blower. And is conveyed from the fine powder outlet 24 to the dust collector and collected. 8) The coarse powder is immediately returned from the classifying chamber C to the crushing chamber B, and the crushing is repeated again. 9) During the crushing operation, the boundary surface between the powder deposit layer in the crushing chamber B and the cavity formed by the jet is monitored by the level sensor 4, and the feed rate of the pulverized material is set higher than the production rate of the fine powder. When the boundary surface rises and reaches a predetermined level, the level sensor 4 operates, and the granulated material supply valve 16 is closed after a set time by an associated timer to interrupt the supply of the granulated material. After that, when the boundary surface is lowered to a predetermined level by continuing the crushing, the level decrease is detected by the level sensor 4. In association with this, the crushed material supply valve 16 is opened, and the supply of crushed material is automatically restored. This operation continues until the work is stopped. 10) During that time, the behavior regarding the powder and the air flow inside the crushing chamber B and the classification chamber C is as described in the section of "action".

[0030]

Since the present invention is configured as described above, it has the following effects. In the airflow type fine pulverizer according to claim 1, (1) the outer peripheral surface of the tip end portion of the spindle forming the core of the injector nozzle is formed into a conical surface that gradually contracts toward the crushing chamber side, A tubular tubular sheet is externally inserted into the core body of the injector / nozzle, and the inner surface of the tubular sheet facing the conical surface of the core body has an inner surface of the core body from the compressed gas introduction side toward the crushing chamber side. A first conical surface having a cone angle larger than the cone angle and a second conical surface or a cylindrical surface having a cone angle smaller than the cone angle of the core body are continuously formed, and the inner surface of the tubular sheet and the core body are formed. In the middle of the gap with the outer surface of the nozzle, there is formed a nod part as a gas passage with the smallest annular cross-sectional area, and the spindle forming the core of the injector / nozzle carries the crushed material from outside the crushing chamber to the crushing chamber. Grinding chamber side to put As the tip is opened,
Since it is formed to be hollow so as to communicate with the crushing material hopper provided outside the crushing chamber, the passing speed of the crushing material supplied from the inside of the hollow spindle may be sufficiently slow, and the gas generated from the gas source as in the conventional technique may be used. Compared with the case where the crushed material passes through the accelerating pipe (or the nozzle) at a high speed, the wear of the member is significantly less, and the disadvantage of contaminating the crushed product can be eliminated. In addition, even if the static pressure inside the crushing chamber is slightly higher than the external environment, the local negative pressure created by the jet flow from the gas passage of the injector / nozzle prevents the crushed material from being blown out from the crushed material hopper. To be done. (2) Moreover, the injector nozzle and counter
Since the nozzle is formed as an annular nozzle, the hollow gas jet that comes out of the annular nozzle contacts the powder layer with a large surface area compared to the case of the gas jet that comes out of the single-hole nozzle. The chance of aspiration and crushing can be increased. (3) Further, since the counter nozzle is installed in the crushing chamber so as to face the center line of the injector nozzle at an obtuse angle, the crushed material from the injector nozzle is injected into the counter nozzle. There is no fear, and wear of the counter nozzle due to injection is prevented. (4) Furthermore, since the cross-sectional area of the passage through which the gas flows in the annular nozzle is formed so as to first sharply decrease and then gradually expand, the gas jet ejected from the annular nozzle is accelerated to a velocity around the sonic speed. The powder thus sucked can be blown off at high speed to promote crushing. (5) Furthermore, since a switching means such as a valve that does not give a stirring action to the crushed material is adopted as a means for transporting the crushed material, not only does the flow of the crushed material be obstructed, but also when the crushed material becomes viscous. It is possible to handle a wide range of crushed materials by preventing the harmful effects that occur in.

In the airflow type fine pulverizer of claim 2, (1) since the hollow spindle or the needle is attached to the tubular sheet so as to be able to advance and retract, the core of these nozzles is attached to the tubular sheet of the nozzle. Since the opening area of the "throat" of the nozzle can be easily and steplessly adjusted by advancing and retracting the nozzle, a wide range of gas source (compressor) can be supported by the nozzle having the same specifications. Further, by narrowing down the opening area of the "throat" to limit the amount of gas input and by taking the classification impeller at the maximum rotation speed, it is possible to obtain a crushed product of ultrafine powder. Furthermore, if the surface of the nozzle that is in contact with the air flow becomes worn due to long-term use, the opening area of the "throat" should be maintained at a predetermined size by advancing the core of the nozzle toward the grinding chamber. You can

[Brief description of drawings]

FIG. 1 is a front view showing a part of an embodiment of the present invention in section.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an enlarged vertical sectional view of an injector nozzle and a pulverized material supply device.

FIG. 4 is a vertical sectional view of a counter / nozzle portion.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is an enlarged cross-sectional view of a base end side of a rotary impeller.

FIG. 7 is an enlarged cross-sectional view of a main part on the tip side of the rotary impeller.

[Explanation of symbols]

2d Granulated material transport passage 2e Coarse powder return passage 7,18 Tubular sheet 7a, 18a Throat 8a, 19c Retention place of compressed gas (annular space) 9 Hollow spindle 13 Granule hopper 16 Switching means such as valve (granule supply) 21) Needle 23 Classifying case 24 Fine powder outlet 26 Classifying means (rotary impeller) 26d Large diameter cylindrical portion 26e Small diameter cylindrical portion 27 Drive shaft 29 Air flow preliminary swirl chamber 30 Inner cylinder 31 Blade 32 Annular partition plate A Equipment B Grinding chamber B ₁ Injector nozzle B ₂ Counter nozzle C Classification chamber α Crossing angle of the center lines of two nozzles β Cone angle of the first conical surface of the tubular sheet γ ₁ Second conical surface of the tubular sheet Cone angle γ ₂ Cone angle of the conical surface formed on the inner surface of the hollow spindle γ ₂ ′ Cone angle of the needle tip δ ₁ Primary clearance δ ₂ Secondary clearance

Claims (2)

[Claims] 1. A crushed material supplied to a crushing chamber through an injector nozzle is crushed by an injector nozzle and a counter nozzle, and fine powder having a certain particle size or less in the crushed product is placed in a classification chamber above the crushing chamber. In an air flow type fine pulverizer which classifies by a classifying means and takes it out of the apparatus, and returns coarse powder having a certain particle size or more to a crushing chamber by a circulating means and repeats crushing again, the counter nozzle is located at the center line of the injector nozzle. It is attached to the crushing chamber so as to face each other at an obtuse angle, and the spindle of the spindle that forms the core of the injector / nozzle is
Knee forming the core of the tip and counter nozzle
Each outer peripheral surface of the tip portion of the dollar is formed into a conical surface that gradually reduces toward the crushing chamber side, and the core body of the injector nozzle and the counter
A tubular sheet with a cylindrical shape is inserted onto the core of the nozzle.
Is the the inner surface of each tubular sheet facing the respective conical surfaces of both the core body toward the crushing chamber side from the compressed gas inlet side,
A first conical surface having a cone angle larger than the cone angle of the core body, and a second conical surface or a cylindrical surface having a cone angle smaller than the cone angle of the core body are continuously formed, each of the tubular sheet in the middle of the gap between the inner and outer surfaces of the core, the throat of a gas passage sectional area of the annular becomes minimum are formed, that to form a core of the injector nozzle spindle
Is crushed in order to carry the crushed material from outside the crushing room into the crushing room.
Crushed material provided outside the crushing chamber with the chamber end open
Hollow is formed so as to communicate the hopper, between said hollow <br/> spindle and crushed material hopper to form a core of the injector nozzle, such as a valve that can be communicated or shut off both switching An air flow type fine pulverizer provided with means. 2. A hollow spindle or needle having a conical surface formed at its tip is attached to each tubular seat with which the tip is engaged by a screwing or other means so as to be able to move forward and backward. Air flow type fine pulverizer described in.