JPH11302702A - Powder dryer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently dry even the powder having relatively large specific gravity. SOLUTION: In a powder dryer for drying powder while floating by hot air by arranging the powder on a powder placing body 10 having many air holes and blowing the hot air from the under side of the powder placing body 10, a stirring means 21 for stirring the powder is disposed above the powder placing body 10. A hot air blowing port 14 for blowing the hot air from the under side of the powder placing body 10 toward the powder is disposed below the powder placing body 10 and a distributor for diffusing the hot air blown from the hot air blowing port 14 is disposed in the under side of the powder placing body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a powder dryer for drying powder such as rapidly solidified metal powder.

[0002]

2. Description of the Related Art For example, a cooled and solidified metal powder is obtained by a water atomization method in which a molten metal is finely divided from an orifice and brought into contact with cooling water. Therefore, it is necessary to forcibly dry after dehydration treatment.

[0003] For this reason, conventionally, there is a type in which a rapidly solidified powder that has been dehydrated is placed on a net, hot air is blown from under the net, and the rapidly solidified powder is forcibly dried while floating with the hot air (eg, JP-A-3-79705).
This has an advantage that it can be dried in a shorter time than a shelf type dryer or the like, and is suitable for drying a substance having a relatively light specific gravity.

[0004]

However, in a conventional powder dryer, when a wet metal powder produced by a water atomizing method or the like is to be dried, a powder having a large specific gravity floats due to hot air. Hateful. Even if the hot air pressure is increased or the amount of hot air is increased, there is a problem that only a blow-through occurs and efficient drying cannot be performed. Therefore,
For example, when the iron powder is wet and agglomerated, the oxidation is promoted inside, so that high quality powder cannot be obtained.

The present invention has been made in view of the above problems, and is intended to efficiently dry even a relatively heavy powder.

[0006]

A first technical means of the present invention for solving this technical problem is to arrange powder on a powder carrier 10 having a large number of ventilation holes, and to provide a powder carrier 1 having a plurality of air holes.
In a powder dryer in which hot air is blown from below and dried while floating the powder with hot air, a stirring means 21 for stirring the powder is provided above the powder placing body 10. .

According to a second technical means of the present invention, a hot air blowing port 14 for blowing hot air from below the powder carrier 10 toward the powder is provided below the powder carrier 10, and the powder carrier 1 is provided.
The point below is that a rectifying plate 16 for diffusing the hot air blown from the hot air blowing port 14 is provided below the zero.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a powder dryer used for forcibly drying rapidly solidified metal powder or the like, and includes a rectangular parallelepiped support base 2 and a cylindrical dryer main body 3 placed on the support base 2. The lower end of the dryer main body 3 is closed by a bottom wall 4, the upper end of the dryer main body 3 is closed by a canopy 5, and the inside of the dryer main body 3 is sealed. The canopy 5 is detachable from the upper end of the dryer main body 3. A support piece 6 is provided in a vertically intermediate portion of the dryer main body 3 so as to protrude inward.

Reference numeral 9 denotes a powder container, which is formed in a cylindrical shape with a bottom having an open upper end. The bottom portion of the powder container 9 is constituted by a mesh through which the powder to be dried cannot pass, and has a large number of ventilation holes. And a powder carrier 10 having the following. The powder container 9 is inserted into the dryer main body 3 from the upper end of the dryer main body 3 by removing the canopy 5, is placed on the support piece 6 in the dryer main body 3, and is an object to be dried. A powder such as a rapidly solidified metal powder is stored in a powder container 9 and a powder carrier 10
It is designed to be placed on top.

Reference numeral 13 denotes a pair of hot air supply pipes, which are disposed in the support base 2, and the hot air blowing port 14 side of each hot air supply pipe 13 penetrates through the bottom wall 4 and protrudes to the lower part in the dryer body 3. I have.
A hot air supply hose is connected to the lower end of each hot air supply pipe 13.
A hot air of an inert gas such as an argon gas or a nitrogen gas is blown from below the powder carrier 10 of the powder container 9 toward the powder on the powder carrier 10.

A rectifying plate 16 is provided below the powder carrier 10 of the powder container 9 so as to diffuse the hot air blown from the hot air blowing ports 14 of the pair of hot air supply pipes 13. Each of the flow regulating plates 16 is disposed so as to obliquely block a portion immediately above the hot air blowing port 14. Each current plate 16 is inclined in the opposite direction to each other, and the hot air blown from each hot air blowing port 14 is widely diffused below the powder carrier 10, and the hot air is blown directly to the powder side on the powder carrier 10. To prevent
The hot air is distributed substantially evenly over the powder side on the powder-carrying body 10 over the whole, and is sent to the powder side.

Reference numeral 19 denotes an exhaust pipe, which is disposed on the canopy 5 and whose suction port 20 side penetrates through the canopy 5 and is introduced into the main body 3 of the dryer. A hot air exhaust hose is connected to the upper end of the hot air exhaust pipe 19, and the hot air of the inert gas supplied into the dryer main body 3 by the pair of hot air supply pipes 13 is discharged by the exhaust pipe 19. It is designed to be discharged outside.

Reference numeral 21 denotes an impeller for stirring, which is a stirring means for stirring the powder. The impeller 21 is radially attached to a lower end of the rotating shaft 22 and has a powder loading member 10.
, And is rotated around a rotation shaft 22 by a motor 23 mounted on the canopy 5, whereby the impeller 21 agitates the powder on the powder carrier 10.

According to the above embodiment, when drying powder such as rapidly solidified metal powder, the canopy 5 is removed, and the powder container 9 containing the rapidly solidified metal powder is dried from the upper end of the main body 3 of the dryer. 3 and placed on the support piece 6, the canopy 5 is attached to the upper end of the dryer main body 3, hot air is supplied into the dryer main body 3 by the hot air supply pipe 13, and the impeller 21 is rotated by the motor 22. Drive.

Then, the hot air of the inert gas is blown from each hot air blowing port 14 of the pair of hot air supply pipes 13, and the blown hot air is widely diffused under the powder carrier 10 by the rectifying plate 16, so that the powder carrier is supplied. The powder 10 is distributed substantially evenly over the entire powder side and is blown toward the powder side. At this time, the impeller 21 stirs the powder on the powder placing body 10 to
Dissolve the agglomerated powder. As a result, the powder carrier 10
The above powder is dried in a short time while being uniformly floated by hot air throughout, to obtain a metal powder having a clean surface.

According to the experimental results, when the Fe—Si—B-based water atomized powder was dried under the drying conditions shown in Table 1, with a conventional powder dryer, the oxygen content of the metal powder was about 500 ppm. However, in the powder dryer of the present invention, the oxygen content of the metal powder is about 100 to 200 ppm
Became.

[0017]

[Table 1]

In the above-described embodiment, the powder carrier 10 having a large number of air holes is formed of a net. Alternatively, the powder carrier 10 may be formed of a punching metal having a large number of fine air holes or a large number of holes. May be constituted by a plate material having the above-mentioned ventilation holes. Further, in the above embodiment, only the powder carrier 10 at the bottom of the powder container 9 is constituted by a net having a large number of vents, and the outer periphery of the powder container 9 is constituted by a plate member. Alternatively, the powder carrier 10 and the outer peripheral portion of the powder container 9 may be constituted by a net or other members having a large number of ventilation holes.

Further, in the above-described embodiment, the impeller 21 which is driven to rotate is used as the stirring means for stirring the powder. However, instead of this, the stirring means for stirring the powder is used to rotate the impeller 21 around the axis. A roll or a screw may be used. Further, in the above embodiment, as the hot air to be blown toward the powder, a hot air of an inert gas such as an argon gas or a nitrogen gas is blown,
Instead of this, depending on the type of powder to be dried, hot air of another type of gas may be blown, or hot air of air may be blown.

[0020]

According to the present invention, the agglomerated powder can be loosened by stirring the powder with the stirring means, and even a relatively heavy powder can be efficiently dried in a short time.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a plan view of the same.

[Explanation of symbols]

 10 net 14 hot air blowing port 21 impeller (stirring means)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Isamu Otsuka 1-1-1, Hama, Amagasaki-shi, Hyogo Prefecture Inside Kubota R & D Laboratories Co., Ltd. (72) Inventor Yoshimasa Okuno 1-1-1, Hama, Amagasaki-shi, Hyogo Stock Company Kubota Technology Development Laboratory

Claims (2)

[Claims] 1. A powder carrier (1) having a large number of air holes.
0) In a powder dryer in which powder is placed on the upper surface and hot air is blown from under the powder carrier (10) to dry the powder while floating with the hot air, the powder is placed above the powder carrier (10). And a stirring means (21) for stirring the powder. 2. A hot air blowing port (14) for blowing hot air from below the powder carrier (10) toward the powder is provided below the powder carrier (10), and below the powder carrier (10). 2. The powder dryer according to claim 1, further comprising a rectifying plate (16) for diffusing hot air blown from the hot air blowing port (14). 3.