JP2500305B2 - Variable gravity fluidized bed equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed apparatus for fluidizing solid particles with a fluid, and more particularly to a technique for reducing the acceleration acting in the fluidized bed to 1 G or less.

[0002]

2. Description of the Related Art A fluidized bed formed by fluidizing solid particles by contacting them with a gas has been conventionally used for heat transfer,
It is widely used in many processes as a place for heat and substance transfer such as combustion, drying, evaporation, and calcination, operation such as state change, and chemical reaction between gas and solid. And recently,
In order to fluidize ultrafine powder, increase processing capacity, and downsize the equipment, a pressurized fluidized bed that operates a fluidized bed under pressure and a centrifugal fluidized bed that gives a centrifugal force field and operates in a gravity field of 1 G or more are new. It is attracting attention as a method.

[0003]

However, in such a conventional fluidized bed, the acceleration of gravity of 1 G or more acts on the solid particles, so that an extremely slow operation or reaction cannot be realized. Therefore, it is an object of the present invention to solve the above problems in the prior art and to provide a variable gravity type fluidized bed apparatus that enables extremely slow operation and reaction.

[0004]

In order to solve the above-mentioned problems, the present invention is a variable gravity fluidized bed apparatus that operates in a zero gravity or microgravity environment, in which a cylindrical container containing solid particles is provided. A fluid supply means for supplying a fluid into the cylindrical container so as to fluidize the solid particles, and a rotating means for rotating the cylindrical container around the center line of the cylinder of the cylindrical container. and, the rotational speed of the rotating means, the acceleration of the centrifugal force generated by the rotation of the fluidized bed portion which is formed in said container, characterized in that as the range of less than 1G in 10¯ ⁴ G or more.

That is, according to the present invention, in a fluidized bed formed by contact between solid particles and a gas, the center of the freeboard portion, which is the upper portion of the fluidized bed, is rotated as the center of rotation, and centrifugal force is applied to the bed portion of the fluidized bed. together with causing, by placing the entire fluidized bed microgravity or zero gravity environment, characterized by generating a gravity 10¯ ⁴ ~1G the fluidized bed unit.

[0006]

According to the present invention, the fluid is supplied by the fluid supplying means into the cylindrical container arranged in the zero gravity or microgravity environment, and the acceleration of the fluidized bed portion formed in the container is 10 by the rotating means. Since the cylindrical container is rotated so that it is in the range of ⁴ G or more and less than 1 G, by changing the rotation speed according to the purpose of use of the fluidized bed, it is possible to obtain the desired slow operation or reaction field. You can

[0007]

EXAMPLE FIG. 1 shows the entire structure of a gravity variable fluidized bed apparatus of an example. This apparatus includes a cylindrical container 1 that holds, for example, silicon nitride as solid particles therein, and a blower 2 as a fluid supply means that supplies nitrogen, which is a fluid, into the cylindrical container 1 so as to fluidize the solid particles. And a motor 3 as a rotating means for rotating the cylindrical container 1 around the center line of the cylinder, and the rotational speed of the motor 3 is controlled by the rotation of the fluidized bed portion formed by the cylindrical container 1. acceleration of the centrifugal force generated is a device which was set to the range of less than 1G in 10¯ ⁴ G or more.

In order to change the acceleration of the fluidized bed portion, the number of revolutions of the cylindrical container 1 may be changed. As a method of this, the motor 3 is made to have a variable speed or the motor 3 and the cylindrical container 1 are changed. A variable speed power transmission device may be provided between the two.

FIG. 2 is a sectional view of a portion of the cylindrical container 1. As described above, for example, silicon nitride is intermittently or continuously put in the fluidized bed portion 4 of the container 1, and the nitrogen supplied from the blower 2 shown in FIG.
Through the dispersion plate 7 from the outer periphery of the fluidized bed 4 to the fluidized bed 4
By flowing into the inside, the solid particles inside are fluidized. Then, the inflowing air is discharged from the exhaust port 8.
Reference numeral 9 is a pulley that transmits the driving force of the motor 3.
Further, reference numeral 10 is a detachable screen.

Such a fluidized bed is under normal pressure, under pressure, or under reduced pressure by appropriately setting the discharge pressure of the blower 2 and the exhaust amount or flow velocity from the exhaust port 8 or by providing the blower 2 on the exhaust side. It is realized in any of the following states.

The fluidized bed apparatus as described above is arranged in a zero gravity or microgravity environment. Such an environment condition is, for example, due to parabolic flight by an aircraft, small rocket, free fall, etc. for a short time. For a long time, by using spacecraft such as artificial hygiene, space shuttle, and space station currently under development,
It can be easily realized.

Under a zero-gravity environment, acceleration due to gravity does not act on the fluidized bed, so that an arbitrary acceleration state of 1 G or less can be obtained by the above-mentioned device. And 1G
A fluidized bed of less than 1 enables slow operation and a reaction between gas and solid which cannot be realized by a fluidized bed of 1 G or more, and is particularly useful for creation of a highly functional material.

For example, a CVD method using a fluidized bed (chemical vapor deposition method) is used as a method for synthesizing silicon nitride capable of electric discharge machining.
Can be considered. This method is a method in which titanium nitride is deposited on the surface of silicon nitride by CVD after fluidizing the silicon nitride. In this method, under the optimum CVD reaction condition, the pressure of the gas for fluidization is usually low (for example, 0.01 atm), and the superficial velocity in the fluidized bed becomes slow, so that silicon nitride is fluidized in the conventional fluidized bed. You can't get the energy to get it done.

One possible solution to this problem is to make the silicon nitride particles small and fluidize them with a small amount of energy, but in some cases good fluidization may not occur due to an increase in adhesion due to pulverization. Many.

According to the present invention, the energy required for fluidization can be reduced by reducing the acceleration acting on the silicon nitride particles, and the optimum flow condition can be satisfied together with the optimum CVD condition.

A specific example of the fluidized bed for realizing such an environment of 1 G or less is shown as operating in the range of 0.05 to 0.5 G with reference to the position of the dispersion plate 7 shown in FIG. , The distance from the center to the dispersion plate 7 (radius) is 5c
When m is m and the angular velocity is ω, 0.05ω ² = 0.05 to 0.5G, so ω is 1.4 to 9.9. Therefore, the rotation speed should be about 10 to 100 rpm. become. In this case, if the solid particles having a particle diameter of 1 mm and a density of 2500 KG / m ³ are fluidized, the supply gas amount is 0 to 1.0 ×.
10¯ may be to ² m ³ / S. The acceleration of the fluidized bed unit can be appropriately selected depending on the conditions of the fluidized bed, from conventional reaction conditions such as 10 ⁴ or G is desirable.

[0017]

According to the above as the present invention, zero gravity or by a cylindrical container disposed under microgravity environment is rotated, the fluidized bed such as the acceleration is in the range of less than 1G in 10¯ ⁴ G or Thus, it is possible to obtain a slow operation or reaction field corresponding to the purpose of use.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the overall configuration of a gravity variable fluidized bed apparatus of an embodiment.

FIG. 2 is a cross-sectional view of a cylindrical container of the gravity variable fluidized bed apparatus.

[Explanation of symbols]

 1 Cylindrical container 2 Blower (fluid supply means) 3 Motor (rotation means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigeru Chiba Inventor Shigeki Chiba Higashikanto Nijo 17-chome 2-1 Hohei-ku, Sapporo Inside the Hokkaido Industrial Development Laboratory (72) Inventor Tomoaki Takada 1-1 Kawasaki-cho, Akashi-shi Kawasaki Heavy Industry Co., Ltd. Akashi Factory (72) Inventor Kazuo Tsutsumi 1-1 Kawasaki-cho, Akashi City Kawasaki Heavy Industry Co., Ltd. Akashi Factory (72) Inventor Yasushi Sakakida 1-1 Kawasaki-cho, Akashi City Akashi Factory Akashi Factory (72) Inventor Hiroyuki Matsumura 1 Kawasaki-cho, Kakamigahara-shi Kawasaki Heavy Industries Ltd. Gifu Factory Examiner Hiroyuki Oguro

Claims (1)

(57) [Claims] 1. A variable gravity fluidized bed apparatus arranged in a zero gravity or microgravity environment, wherein a cylindrical container having solid particles inside, and the cylindrical container for fluidizing the solid particles. A fluid supply means for supplying a fluid therein, and a rotating means for rotating the cylindrical container about a center line of a cylinder of the cylindrical container, and a rotation speed by the rotating means is set in the container. gravity variable fluidized bed apparatus, wherein the acceleration of the centrifugal force generated by the rotation of the fluidized bed unit to be formed was set to a range of less than 1G in 10¯ ⁴ G or more.