JP4975998B2 - Gas circulation crusher - Google Patents

Description

  The present invention relates to a gas circulation type pulverizing apparatus for finely pulverizing powders of resins, inorganic compounds, metal compounds and the like.

  2. Description of the Related Art Conventionally, a pulverizer that finely pulverizes a powder that is quantitatively supplied from a powder supply device by an ejector action of a high-pressure gas injected from an injection nozzle into a pulverization chamber is known.

  There are two types of pulverizers: a type in which powder is swirled at high speed in a pulverization chamber and pulverized by collision between powders, and a type of collision type in which pulverization is performed by colliding with a collision plate provided in the pulverization chamber.

  In general, the gas flow rate in the spray nozzle of a grinder can be expressed as a function of the Mach number. The speed of sound varies depending on the physical properties of the gas, and it is more advantageous for pulverization to use a gas having a higher sound speed. That is, if a large flow velocity can be obtained, a large impact force can be applied at the time of collision between particles or between a particle and a collision plate, and the pulverization limit particle diameter becomes smaller.

  Usually, air or nitrogen gas is used for pulverization, and the flow rate at which the Mach number is 1 at 20 ° C. is 343 m / sec for air and 349 m / sec for nitrogen gas. At the collision speeds obtained at these speeds, there is a problem that sufficient fine pulverization cannot be achieved to the required particle size.

In order to eliminate such inconvenience, in the pulverization apparatus described in Patent Document 1, the powder is pulverized using helium gas or hydrogen gas as the high-pressure gas. When helium gas is used, the gas flow rate at which the Mach number is 1 at 20 ° C. is 1007 m / sec, and in the case of hydrogen gas, 1304 m / sec, so that the collision energy acting on the powder particles can be increased. The powder can be effectively pulverized.
JP 2003-340308 A

  By the way, in the conventional crushing apparatus using helium gas or hydrogen gas as the high pressure gas, the outlet 32 of the powder supply device 31 and the hopper 34 of the crusher 33 are connected by a connecting pipe 35 as shown in FIG. Due to this configuration, when helium gas or hydrogen gas is injected from the injection nozzle 36, the pressure drop in the connecting pipe 35 increases because of the very high speed, and the inside of the connecting pipe 35 and the powder supply device 31 A relatively large pressure difference occurs between them, and the amount of powder supplied to the pulverizer 33 becomes unstable. Therefore, there is an inconvenience that the particle size of the pulverized powder is not stable.

  An object of the present invention is to provide a gas circulation type pulverization apparatus capable of stabilizing a supply amount of powder to a pulverizer and obtaining a pulverized product having a stable quality.

  In order to solve the above-mentioned problems, in the present invention, a powder supply device for quantitatively supplying powder and a high-pressure gas injection nozzle, and a powder supply device by an ejector action of high-pressure gas injected from the injection nozzle A pulverizer that pulverizes powder supplied quantitatively from the pulverizer, a solid-gas separator that separates the solid-gas mixed fluid discharged from the pulverizer outlet into solid and gas, and the solid A circulation path that communicates a gas outlet of the gas separator and a gas inlet of the injection nozzle, and a compressor that compresses the gas flowing in the circulation path, and one of helium gas and hydrogen gas as the gas, or these In the gas circulation type pulverization processing apparatus using a mixed gas, the powder supply device and the pulverizer are housed in a sealed box, and a powder supply path supplied from the powder supply device to the pulverizer In And its inside and inside the box is to that adopted the configuration in which a communication passage communicating.

  As described above, the powder supply device and the pulverizer are accommodated in the hermetically sealed box, and the communication path that communicates the inside of the box with the powder supply path that is supplied from the powder supply device to the pulverizer When helium gas or hydrogen gas is injected from the injection nozzle and the pressure in the pulverizer decreases, the gas sealed in the box flows into the supply path, so the pressure drop in the supply path is small. Thus, the powder can be stably supplied into the pulverizer from the powder supply device, and a pulverized product with stable quality can be obtained.

  Further, in the conventional apparatus, high sealing performance is required to prevent the entry of outside air. However, in the present invention, since the powder supply device is housed in the box, the sealing performance of the powder supply device itself is improved. There is no need, and a powder supply device having a simple configuration can be employed.

  Furthermore, the helium gas or hydrogen gas that flows from the circulation path to the injection nozzle and is injected from the injection nozzle into the pulverizer flows at a very high speed in the pulverizer and emits a relatively high sound when it flows. Since each of the machines is housed in a box, the sound can be effectively silenced by the box, and a gas circulation type pulverizing apparatus with less noise can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. As shown in FIG. 1, the powder supplied quantitatively from the powder supply device 1 drops by gravity in a supply path 2 connected to the powder outlet, and enters the hopper 4 of the crusher 3 provided therebelow. To be supplied.

  Here, the powder supply apparatus 1 may be a screw feeder, or may be a table feeder in which the powder supplied onto the rotary table is scraped off to the outer periphery of the rotary table by a scraper. Between the lower end of the supply path 2 connected to the powder outlet of the powder supply apparatus 1 and the hopper 4 of the crusher 3, a predetermined interval L as a communication path is provided as shown in FIG. Is provided.

  The pulverizer 3 has an injection nozzle 5, and the powder supplied into the hopper 4 by the ejector action of the high-pressure gas injected from the injection nozzle 5 is placed in a pulverization chamber (not shown) provided in the pulverizer 3. Injected and pulverized in the pulverization chamber.

  Here, as the pulverizer 3, a jet mill is used in which the powder is swirled at a high speed in the pulverization chamber and pulverized by collision between the powders, but the powder collides with an impact plate provided in the pulverization chamber. You may make it use the grinder which was made to grind | pulverize.

  The high-pressure gas may be helium gas, hydrogen gas, or a mixed gas thereof. In the embodiment, helium gas is used.

  As shown in FIG. 1, the outlet of the pulverizer 3 and a solid-gas separator 6 comprising a cyclone separator are connected by a passage 7, and the solid-gas mixed fluid containing the powder after the pulverization treatment is supplied to the solid-gas separator 6. And is separated into helium gas and powder, and the powder is fed into a fine powder collection container 6 a connected to the solid-gas separator 6.

  On the other hand, helium gas is sent to a dust collector 8 comprising a filter, and the powder contained in the helium gas is removed. A gas outlet of the dust collector 8 and the injection nozzle 5 of the pulverizer 3 are connected by a circulation path 9.

  The circulation path 9 is provided with a low-pressure tank 11, a compressor 12, and a high-pressure tank 13 in this order from the dust collector 8. The helium gas is compressed by the compressor 12 and stored in the high-pressure tank 13 in a high pressure state. It is fed to the injection nozzle 5.

  A gas curdle 15 is connected to the low-pressure tank 11 via a supply path 14, and helium gas is supplied from the gas curdle 15 into the low-pressure tank 11 by opening a valve 16 provided in the supply path 14. It has become.

  A valve 17 is provided at the gas inlet of the circulating helium gas in the low-pressure tank 11, and an exhaust valve 19 is provided at the exhaust pipe 18 branched from the inlet of the valve 17.

  As shown in FIG. 2A, the powder supply device 1 and the pulverizer 3 are accommodated in a sealed box 20. As shown in FIG. 1, the box 20 and the low-pressure tank 11 are connected by a passage 21. Further, an exhaust path 22 is connected to the box 20, and a replacement valve 23 is provided in the exhaust path 22.

  The gas circulation type pulverization apparatus shown in the embodiment has the above-described structure, and the air in the gas circulation path is replaced with helium gas when the powder is pulverized. In the replacement, the bubble 17 is closed and the exhaust valve 19 and the replacement valve 23 are opened. Thereafter, the valve 16 is opened, and helium gas is supplied from the gas curd 15 to the low pressure tank 11.

  Due to the supply of the helium gas, the helium gas flows from the low-pressure tank 11 to the box 20 and the circulation path 9, the air in the box 20 is from the exhaust path 22, and the air in the helium gas circulation path is from the exhaust pipe 18. The box 20 and the circulation path are replaced with helium gas.

  After the replacement of the helium gas, the exhaust valve 19 and the replacement valve 23 are closed, the valve 17 is opened, the helium gas flows through the circulation path 9, and the ejector action of the high-pressure helium gas injected from the injection nozzle 5 The powder supplied quantitatively from the powder supply device 1 is pulverized by being jetted at high speed into the pulverization chamber of the pulverizer 3.

At this time, the inside of the hopper 4 of the pulverizer 3 has a negative pressure. However, since the hopper 4 and the supply path 2 are provided with a distance L, helium gas filled in the box 20 from the gap portion 24 is provided. It flows into the pulverizer side, and there is little decrease in the pressure in the supply path 2. For this reason, the powder discharged from the powder supply apparatus 1 can be quantitatively supplied from the supply path 2 into the hopper 4 of the pulverizer 3, and a stable pulverized product can be obtained.

  In FIG. 2, an interval L is provided between the lower end of the supply path 2 and the hopper 4 so that the helium gas in the box 20 flows into the hopper 4 when the pressure in the hopper 4 decreases. The lower end of the path 2 may be connected to the hopper 4 and a through hole may be provided in the supply path 2 to communicate the inside with the box 20.

Schematic of the gas circulation type pulverization processing apparatus according to the present invention (a) is a cross-sectional view showing a pulverization processing section, (b) is a cross-sectional view showing an injection nozzle section Schematic showing a pulverization processing unit of a conventional gas circulation pulverization processing apparatus

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Powder supply apparatus 2 Supply path 3 Crusher 5 Injection nozzle 9 Circulation path 12 Compressor 20 Box

Claims (1)

It has a powder supply device that supplies powder in a fixed amount and a high-pressure gas injection nozzle, and the powder supplied from the powder supply device is injected into the grinding chamber by the ejector action of the high-pressure gas injected from the injection nozzle. A pulverizer that performs pulverization, a solid-gas separator that separates the solid-gas mixed fluid discharged from the outlet of the pulverizer into solid and gas, a gas outlet of the solid-gas separator, and a gas of the injection nozzle A gas circulation type pulverization process comprising a circulation path communicating with the inlet and a compressor for compressing the gas flowing in the circulation path, wherein one of helium gas and hydrogen gas or a mixed gas thereof is used as the gas. In the device
The powder supply device and the pulverizer are housed in a sealed box, and a communication path is provided in the powder supply path that is supplied from the powder supply device to the pulverizer to communicate the interior with the box. A gas circulation type pulverization apparatus characterized by the above.

Images