KR101929342B1 - Apparatus for fused beads using high temperature flow tube and Manufacturing method using the same - Google Patents

Abstract

The present invention relates to a continuous flow pipe formed horizontally; A raw material inlet through which the raw material is vertically introduced into one side of the continuous air flow tube; A gas torch provided at one end of the continuous air flow tube for preheating the introduced raw material; A plasma section for generating a plasma to melt the preheated raw material to form beads; And a recovering part for recovering the molten bead downward from the other side of the continuous flow pipe, wherein the throat part prevents rapid quenching of the molten bead that has passed through the plasma part section .

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a small-sized molten bead using a continuous hot air flow tube,

The present invention relates to an apparatus for manufacturing a small-sized molten bead using a continuous hot air flow tube, and more particularly, to a method for manufacturing a small-sized molten bead using a continuous high- Height of the molten beads.

Zirconia (ZrO ₂ ) is used in refractories, engineering ceramics and abrasion resistant ceramics because of its high fire resistance, chemical stability and high strength and toughness. It is also used as electronic ceramics because of its high electrical conductivity at elevated temperature in combination with other oxides.

Since zirconia undergoes various phase changes depending on the temperature and changes its volume, the mechanical properties are deteriorated due to shear deformation. Therefore, cubic oxide, CaO, magnesia (MgO) or yttria (Y ₂ O ₃ ) Stabilized zirconia stabilizes the phase transition.

Ceramic beads using the high strength and abrasion resistance characteristics of stabilized zirconia are used for grinding and dispersing the fine particles, and characteristics such as high density, high strength, hardness, high abrasion resistance and size distribution are important.

Ceramic beads include a method of forming and sintering a powder and a method of melting and solidifying it with drops.

As in Patent Document 1, a conventional method for producing a molten bead is mainly a method in which a starting material is melted in a furnace such as an electric arc furnace, dispersed in droplets, and solidified.

However, the beads produced by the conventional melting method have a size of 0.01 to 2.0 mm and the size distribution is very wide. Therefore, the recovery rate of the target size is extremely low by 20 ~ 30%, the quality is deteriorated due to many internal defects such as pores, It consumes electric energy because it is melted for 3 ~ 6 hours and there is a problem that the working time is long and the productivity is low in a single batch method.

1. Korean Patent Publication No. 2010-0135848

In order to solve the above problems, the present invention provides a method for manufacturing a small-sized molten bead using a continuous high-temperature gas pipe and plasma, which has a high yield, low input energy and high quality.

According to the present invention, there is provided an apparatus for manufacturing a small-sized molten bead using a continuous air flow tube, comprising: a horizontal air flow tube; A raw material inlet through which the raw material is vertically introduced into one side of the continuous air flow tube; A gas torch provided at one end of the continuous air flow tube for preheating the introduced raw material; A plasma section for generating a plasma to melt the preheated raw material to form beads; And a recovering part for recovering the molten bead downward from the other side of the continuous flow pipe, wherein the throat part prevents rapid quenching of the molten bead that has passed through the plasma part section .

The gas torch is preheated to 1,500 to 2,000 DEG C, and the plasma part is heated to 3,000 DEG C or more.

And the recovery unit is provided with an exhaust fan for forming a continuous air flow pipe at a negative pressure.

As another embodiment of the present invention, a method of manufacturing a molten bead using a molten bead production apparatus includes: a step of preparing a raw material; Forming a continuous air flow tube at a negative pressure; Activating the plasma section to raise the temperature to 3,000 DEG C or higher; Heating the cryogenic portion to a temperature of 800 to 1,500 占 폚; Igniting the gas torch and adjusting it to 1,500 to 2,000 DEG C; A step of charging the raw material, preheating the raw material with a gas torch, melting in a plasma part to form beads, passing the mixture through a thirst section, and collecting the beads solidified by the thirst.

The raw material preparation step is characterized in that a powder obtained by mixing zirconia and a stabilizer is mixed and pulverized with a ball mill and spray-dried with a spray dryer to obtain a granular powder.

The present invention relates to a high-quality small melting bead having a small bead yield of 0.05 to 0.5 mm and a high defectivity of 80% or more by passing through a tube of controlled temperature in order to avoid quenching of the molten bead having passed through the plasma section. Can be produced.

In addition, energy can be saved by preheating the material with a hot torch and plasma melting without directly manufacturing the material as a melt, and productivity can be improved by continuously working.

The stabilized zirconia molten bead according to the present invention can be used as a medium of a surface treatment apparatus or a sandblasting apparatus.

1 is a schematic view of an apparatus for manufacturing a molten bead according to the present invention.
2 is a flow chart of a method of manufacturing a molten bead according to the present invention.
Figure 3 is an electron micrograph of the raw material prepared with the spray dryer of the present invention.
4 is an electron micrograph of molten beads according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the particular forms disclosed. And shall not interpret it.

FIG. 1 is a schematic view of an apparatus for manufacturing a molten bead according to the present invention. The apparatus includes a horizontal air flow pipe 10, a raw material inlet 20 for vertically feeding a raw material to one side of the continuous air flow pipe, A gas torch 30, a plasma unit 40 for generating a plasma to melt the preheated raw material, a thruster 50 for adjusting the temperature of the molten bead, and a recovery unit 70 for recovering the molten bead vertically do.

The continuous airflow tube 10 is a tube made of quartz tube or the like and is formed substantially horizontally, and a raw material inlet is formed vertically at one end. The outlet air flow direction of the continuous flow pipe may be upward or downward depending on the flow of the carrier gas and the characteristics of the beads.

The gas torch 30 is controlled to preheat the raw material to 1,500 to 2,000 DEG C using oxygen, hydrogen, butane and propane. At this time, raw materials having a relatively small particle size may be melted and moved to a plasma section by a carrier gas such as air.

The plasma section 40 generates RF or DC arc plasma to raise the temperature of the plasma section to 3,000 DEG C or higher to melt spherical molten beads when the raw materials loaded in the carrier gas are melted. The plasma voltage is 600 V and the current is about 100 A.

The heating unit 50 is heated by resistance heating or induction heating at a temperature of 800 to 1,500 DEG C to prevent quenching of the beads formed in the plasma section.

The recovery unit (70) is provided with an exhaust fan (71) for forming a negative pressure with an apparatus for collecting beads solidified with the cooling. The carrier gas is discharged upward by the exhaust fan 71, and the solidified beads are collected in the collecting part 72 by gravity.

An inlet for injecting outside air can be added to the collecting part to prevent an increase in internal temperature of the collecting part and a classification device can be added to the bottom to collect the bead particle size.

The present invention can continuously perform the process by continuously supplying the raw material from the supply unit 60 to the inlet 20, thereby efficiently using the thermal energy than the batch type, thereby reducing the manufacturing cost and increasing the productivity.

In addition, since preheating is performed in the gas toothed portion and a melting process is performed in the plasma portion, the small particles can be fused and grown to an appropriate size of fine particles, so that a relatively uniform particle size of the molten beads can be produced.

In addition, although the quality of the bead is deteriorated due to the isolation of the pores in the bead due to the conventional quenching, the quality of the bead can be improved by reducing the thermal shock and pore,

FIG. 2 is a flow chart of a method of manufacturing a molten bead using a small-sized molten bead production apparatus using the continuous hot air stream tube according to another embodiment of the present invention.

1. Preparation of raw materials

Zirconium oxide (ZrO ₂ ) powders and precursors can be used as raw materials from which molten zirconia (ZrO ₂ ) can be produced.

Zirconia precursor as _{Zirconium acetate (Zr (CH 2 COO} ) 2), Zirconium nitrate (ZrO (NO 3) 2), Zirconium chloride (ZrOCl 2 and _{8H 2 O), Zirconium hydroxide (} Zr (OH) 4 and xH ₂ O) , Zirconium sulfate (ZrSO ₄揃 4H ₂ O), zirconium phosphate (ZrO ₂揃 P ₂ O ₅ ), and zirconium propionate (Zr (CH ₃ -CH ₂ COO) ₂ ) Combination can be done.

As the stabilizer, oxide powders or precursors such as yttria or ceria can be used, and Al ₂ O ₃ , MgO, MnO ₂ , Fe ₂ O ₃ , Fe (ClO ₃ ) ₂ , CuO, TiO ₂ , Sb ₂ O ₃ , ZnO, CaO, La ₂ O ₃ , SrO, BaO, or the like can be prepared.

Yttria (Y ₂ O ₃₎ precursor as Yttrium hydroxide to prepare a _{(Y (OH) 3),} Yttrium chloride (YCl 3, YCl 3 and _{6H 2 O), Yttrium fluoride (} YF 3) yttrium salts such as powder Or a combination of two or more.

Ceria (CeO ₂ ) Examples which may be produced precursor _{Cerium acetate (Ce (CH 3 CO} 2) 3), Cerium carbonate (Ce 2 (CO 3) 3), Cerium chlorate (Ce (ClO 3) 2), Cerium hydride (CeH 3, CeH 2.69 ), Or a combination of two or more thereof.

The powder mixture of zirconia and stabilizer is mixed and ground with a ball mill and spray-dried with a spray drier to obtain a granular powder as shown in Fig. 3, calcined at a temperature of about 1,000 DEG C, and 50 to 150 mu m of raw material is fed into a feeder do.

2. Formation of sound pressure of continuous air flow tube

The exhaust fan 71 of the recovery section is operated to form the air flow in the continuous air flow pipe 10, thereby making the continuous air flow pipe into a negative pressure state. Air is used as the carrier gas, but inert gas such as He, Ne, N ₂ can be used depending on the raw material characteristics.

3. Plasma operation

The plasma generator is operated to raise the temperature to 3,000 DEG C or higher. The raw material preheated in the gas torch is melted while passing through the plasma section and is converted to the bead state by surface tension. At this time, relatively small particles can be fusion-grown to obtain a relatively uniform particle size of molten beads.

4. Suspension operation

The holding portion 50 is heated to a temperature of 800 to 1,500 DEG C to transfer the bead to the collecting portion while preventing rapid cooling of the bead formed in the plasma section.

5. Gas torch ignition

Gas torch is ignited and adjusted to 1,500 ~ 2,000 ℃ to preheat the raw material.

6. Bead collection

 Collect the frozen solidified beads. The solidified beads are collected in the collecting part 72 by gravity and the carrier gas is discharged upward by the exhaust fan 71. [

FIG. 4 is an electron micrograph of a molten bead produced according to the present invention, in which 3 Y (3 mole% yttria) stabilized zirconia granule powder is prepared, and the plasma current is prepared under the condition of 100 A cryogenic part at 1,400 ° C.

FIG. 4A is an electron micrograph showing a molten bead having a size of 30 to 60 μm, and FIG. 4B is an electron micrograph showing a molten bead having a size of 50 to 100 μm.

The stabilized zirconia molten bead according to the present invention can be used as a medium of a surface treatment apparatus or a sandblasting apparatus.

10: continuous flow tube 20: feed inlet
30: gas torch 40: plasma part
50: stand portion 60:

Claims (9)

A horizontally formed continuous flow pipe;
A raw material inlet through which the raw material is vertically introduced into one side of the continuous air flow tube;
A gas torch provided at one end of the continuous air flow tube for preheating the introduced raw material;
A plasma section for generating a plasma to melt the preheated raw material to form beads;
A thermostat for regulating the temperature of the molten bead and
And a collecting unit for collecting the molten beads downward from the other side of the continuous flow pipe,
Wherein the throat portion prevents rapid cooling of the molten bead having passed through the plasma section. The method according to claim 1,
Wherein the gas torch is preheated at a temperature of 1,500 to 2,000 占 폚. The method according to claim 1,
Wherein the plasma section is heated to 3,000 DEG C or higher. The method according to claim 1,
Wherein the recovery unit is provided with an exhaust fan for forming a continuous air flow pipe at a negative pressure. A method of manufacturing a molten bead using the apparatus for manufacturing a molten bead according to any one of claims 1 to 4,
1) Preparation of raw material to obtain granular powder by mixing powder of zirconia and stabilizer mixed with ball mill and spray drying with spray drier
2) forming a continuous air flow tube at a negative pressure
3) activating the plasma section to raise the temperature to 3,000 DEG C or higher
4) heating the thirst portion to a temperature of 800 to 1,500 캜
5) The step of igniting the gas torch and adjusting it to 1,500 ~ 2,000 ℃
6) The raw material is charged, preheated by the gas torch, melted in the plasma part to form beads,
7) collecting the frozen solidified beads. ≪ RTI ID = 0.0 > 8. < / RTI >

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