JP2002166161A - Apparatus for manufacturing inorganic spheroidized particle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus manufacturing inorganic spheroidized particles, which can efficiently obtain excellent inorganic spheroidized particles by keeping the ambient temperature in a flame formation region of a melting chamber within a prescribed temperature range, and cope with various processing conditions such as the type and particle size of inorganic raw material powder, and retention time. SOLUTION: In an apparatus T for manufacturing inorganic spheroidized particles comprising a melting chamber 1 which has a burner 5 in its ceiling part 4 and of which the sidewall 2 is formed with a refractory, and a cooling chamber 8 which has a water-wall structure and is connected to the melting chamber, the melting chamber is divided into an upper zone A and a lower zone B, a plurality of cooling gas supply means 6 jetting cooling gas along the inner wall surfaces of the upper and lower zones A and B are installed in the circumferential direction, and the ambient temperature in the upper zone A is kept 300-600 deg.C lower than the melting temperature of the inorganic raw material powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing inorganic spheroidized particles such as silica.

[0002]

2. Description of the Related Art For example, a technique for obtaining inorganic spheroidized particles by passing an inorganic raw material powder such as silica through a combustion flame from a combustion device using oxygen or oxygen-enriched air and melting the resulting powder is cooled. It is known.

In order to obtain good inorganic spheroidized particles, it is necessary to maintain the combustion flame temperature at or above the melting temperature of the inorganic raw material powder. Since the gas is entrained in the combustion flame by convection, the combustion flame temperature is affected by the ambient temperature in the combustion flame formation region.

[0004] That is, if the ambient temperature in the combustion flame formation region in the melting chamber is maintained too high, the combustion flame temperature rises, the rate of enlargement of the inorganic spheroidized particles increases, and the inorganic spheroidizing on the side wall in the melting chamber. The amount of particles attached increases, the frequency of cleaning the melting chamber increases, and the productivity decreases.

On the other hand, if the temperature of the atmosphere in the combustion flame forming region in the melting chamber is kept too low, the combustion flame temperature is lowered, the inorganic raw material powder is not sufficiently melted, and good-quality inorganic spheroidized particles are obtained. Can not be done.

[0006] Therefore, in order to efficiently obtain good inorganic spheroidized particles, it is very important to maintain the ambient temperature in the flame forming region in the melting chamber within a predetermined temperature range.

Therefore, as an example of an apparatus for producing inorganic spheroidized particles, Japanese Patent Application Laid-Open No. 62-241542 discloses a water-cooling jacket provided on the outer surface of a refractory wall of a melting chamber and changing the amount of cooling water to change the amount of cooling water. A device for producing inorganic spheroidized particles for maintaining the temperature at 600 to 1000 ° C. and forming a coating layer of spheroidized particles having a thickness corresponding to the refractory wall temperature to prevent adhesion of the inorganic spheroidized particles to the melting chamber. Also, Japanese Patent Application Laid-Open No. 11-71107 discloses that the entire apparatus has a water-cooled wall structure, and cooling air is supplied around the combustion flame to suppress convection of the combustion gas to prevent the inorganic spheroidized particles from adhering to the melting chamber. An apparatus for producing inorganic spheroidized particles to be prevented is disclosed.

[0008]

However, the above prior art can prevent the adhesion of the inorganic spheroidized particles to the melting chamber, but both control the ambient temperature in the flame forming area in the melting chamber. Therefore, there is a problem that the combustion flame temperature cannot be maintained higher than the melting temperature of the inorganic raw material powder, and good inorganic spheroidized particles cannot be efficiently obtained. Furthermore, there is a problem that it is not possible to cope with various processing conditions such as the type, particle size, and residence time of the inorganic raw material powder.

Therefore, according to the present invention, good inorganic spheroidized particles can be efficiently obtained by maintaining the ambient temperature in the flame forming region of the melting chamber within a predetermined temperature range, and the type, particle size and retention of the inorganic raw material powder can be improved. An object of the present invention is to provide an inorganic spheroidized particle production facility that can cope with various processing conditions such as time.

[0010]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a melting chamber in which a ceiling has a combustion device, a side wall is made of refractory, and a water cooling system connected to the melting chamber. In an apparatus for producing inorganic spheroidized particles comprising a cooling chamber having a wall structure, the melting chamber is partitioned into an upper zone and a lower zone, and
A plurality of cooling gas supply means for jetting a cooling gas along the inner wall surfaces of the upper band and the lower band are provided in the circumferential direction, and the atmosphere temperature of the upper band is set to 300 to 600 ° C. higher than the melting temperature of the inorganic raw material powder. This is an apparatus for producing inorganic spheroidized particles which is kept low.

It is preferable that a straight body portion and a funnel portion having a tapered shape be provided at a lower end portion of the cooling chamber.

Further, it is preferable that a duct communicating with a collecting device having an outside air suction port at one end and a suction means at the other end is provided below the cooling chamber.

[0013]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an inorganic spheroidized particle manufacturing apparatus T according to the present invention, which is generally provided with a combustion device 5 on a ceiling part 4 and a side wall 2 formed of a refractory material such as high-purity alumina. 1 and a cooling chamber 8 of a water cooling structure connected to the lower part of the melting chamber 1.

The melting chamber 1 gradually increases in size as the cross-sectional area of the chamber goes downward, and a plurality of nozzles serving as cooling gas supply means 6 are provided at each stepped portion 3 of the indoor wall in the circumferential direction. The cooling gas (air) is ejected downward from an ejection hole 7 which is formed at the tip of the nozzle 6 and opens downward, thereby lowering the wall surface temperature of the side wall 2.

The melting chamber 1 has an upper band A and a lower band B
The upper zone A is provided with a temperature controller and a temperature detecting means (not shown), and the flow rate of the cooling gas ejected from the nozzle 6 is adjusted by a temperature signal from the temperature controller and the temperature detecting means. The temperature of the atmosphere in the flame formation zone of zone A is 300 to 600 ° C. lower than the melting temperature of the inorganic raw material powder.
Keep low. Specifically, when the inorganic raw material powder is MgO, the melting temperature is 2800 ° C.,
In the case of 00 ° C. and TiO ₂ ,
In the case of 5 ° C. and Al ₂ O ₃ , 1450 to 175
In the case of 0 ° C. and SiO ₂ , the temperature of the upper zone A is similarly controlled to 1113 to 1413 ° C.

The reason for lowering the ambient temperature of the upper zone A by 300 to 600 ° C. than the melting temperature of the inorganic raw material powder is as follows.
When the temperature is lower than 300 ° C., the enlargement rate of the inorganic spheroidized particles increases, the amount of the molten scattered particles attached to the side wall 2 increases, the frequency of cleaning the side wall increases, and the productivity deteriorates.
If the temperature is higher than ℃, the spheroidization ratio is poor and the quality is also deteriorated.

It is preferable that the upper band A is a flame forming section formed by the combustion device 5.

The lower zone B is provided for the purpose of maintaining the combustion flame temperature of the upper zone A, that is, for the purpose of preventing a decrease in temperature due to heat loss in the opening of the cooling chamber 8 connected thereto. Then, the cooling gas (air) from the cooling gas supply means 6 is jetted downward to prevent the inorganic spheroidized particles from adhering to the side wall 2.

The burner, which is the combustion device 5 provided on the ceiling 4 of the melting chamber 1, is not limited as long as it has a uniform combustion flame and can stably burn, but as shown in FIG. A first supply pipe 21 having an opening 21a having a divergent shape at the front end is disposed at an outer peripheral portion of the raw material powder supply pipe 20 having a divergent opening 20a. A fuel gas flow path P ₁ is formed between the first supply pipe 21 and a second supply pipe 22 having a straight-moving portion at a tip thereof at a predetermined interval on an outer peripheral portion of the first supply pipe 21 and having a cooling water circulation flow path 23. And a combustion gas flow path P ₂ made of oxygen or oxygen-enriched air is formed between the first supply pipe 21 and the second supply pipe 22. the road P ₁ and the combustion gas channel P _2, the second test At the tip of the tube 22, and a burner having a flame stabilizing unit 24 composed of the recess 24a which opens to the front than the combustion gas flow path P ₂ are suitable.

The cooling chamber 8 has a water-cooled wall structure, a compact installation area, and a sufficient heat transfer area.
And a funnel part 10 having a tapered end at the lower end. The inorganic spheroidized particles spherical in the melting chamber 1 are cooled to, for example, 400 ° C.

Further, a duct 12 having an outside air suction port 11 at one end and a communication end with a collection device having a suction means (not shown) is provided at the lower end of the cooling chamber 8 at the other end.

Next, the operation of the apparatus T for producing inorganic spheroidized particles having the above configuration will be described.

From the raw material powder supply pipe 20, for example,
A part of the combustion gas such as MgO powder and air or pure oxygen or oxygen-enriched air is supplied from the fuel gas passage to LPG, LN.
A gaseous fuel such as G is ignited by supplying the remaining combustion gas such as air, pure oxygen or oxygen-enriched air from the combustion gas flow path.

That is, the inorganic raw material powder is supplied together with a part of the combustion gas into a high-temperature combustion flame formed by the fuel gas and the combustion gas, and is heated in the combustion flame and melted in a floating state. Spheroidize. The spheroidized molten particles eventually scatter outside the combustion flame region. However, the upper zone A controls the amount of cooling gas jetted from the nozzle 6 based on the room temperature (atmosphere temperature in the flame formation region) to thereby control the inorganic raw material powder. Is maintained at 300 to 600 ° C. lower than the melting temperature. Therefore, the combustion flame temperature can be maintained at or above the melting temperature of the inorganic raw material powder. Furthermore, appropriate combustion flame temperature control according to various processing conditions becomes possible. In addition, the lower zone B holds the combustion flame temperature of the upper zone A, and the cooling gas from the nozzle 6 is supplied to the vicinity of the inner surface of the side wall 2 in a downward direction. Does not fuse (adhere) to the inner surface of the side wall 2.

The spheroidized inorganic spheroidized particles are cooled to about 400 ° C. while falling through the cooling chamber 8 and fall into the duct 12, and are dropped by the air sucked from the outside air suction port 11. It is cooled to about 200 ° C. and collected in the collection device.

Further, since the inorganic spheroidized particles dropped into the duct 12 are cooled to about 400 ° C., the amount of suction air necessary for cooling the particles to 200 ° C. may be small, and an expensive collecting device In addition to the need to increase the capacity, the bag filter in the collecting device does not need to be used for high temperatures, so that an inexpensive bag filter can be used.

In the above embodiment, one burner is shown as the burner 5, but a plurality of burners 5 may be provided, and the number of burners 5 may be selected according to the production amount of the inorganic spheroidized particles. .

[0028]

As is apparent from the above description, according to the present invention, the melting chamber is divided into an upper zone and a lower zone, and the cooling gas is jetted along the walls of the upper zone and the lower zone. A plurality of cooling gas supply means are provided in the circumferential direction to maintain the ambient temperature of the upper zone of the melting chamber lower by 300 to 600 ° C. than the melting temperature of the inorganic raw material powder. Can be maintained in an appropriate range by adjusting the cooling gas ejection amount from the cooling gas supply means. That is, the combustion flame temperature can be maintained at a temperature optimal for melting the inorganic raw material powder, and high-quality inorganic spheroidized particles can be obtained.

The lower zone prevents the flame temperature from being lowered due to the heat loss of the opening of the cooling chamber connected thereto, and suppresses the side wall temperature by flowing the cooling gas from the cooling gas supply means along the furnace wall. Therefore, it is possible to prevent the molten particles scattered from the combustion flame from adhering to the side wall.

By providing a straight body at the upper part of the cooling zone and a funnel part having a tapered shape at the lower end, a sufficient heat transfer area can be ensured with a compact installation area, and the heating area is reduced. The sensible heat of the inorganic spheroidized particles can be cooled (extracted) to a desired temperature.

Further, a duct having an outside air suction port at one end and a duct communicating with the collecting device at the other end is provided below the cooling zone, so that the cooled inorganic spheroidized particles can be removed from the outside air. The cooling can be further performed by suction, and the amount of outside air sucked is small, so that the piping communicating with the collecting device can be made thinner, and there is no need to increase the capacity of the collecting device on the downstream side.

[Brief description of the drawings]

FIG. 1 is a sectional view of an apparatus for producing inorganic spheroidized particles according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a sectional view of the combustion device of FIG. 1;

[Explanation of symbols]

1-melting chamber, 2-side wall, 3-step, 4-ceiling, 5
Combustion device, 6-nozzle, 7-outlet, 8-cooling room, 9-
Straight body portion, 10 funnel portion, 11 outside air suction port, 12 duct, A upper band, B lower band, T inorganic spheroidized particle manufacturing apparatus.

Claims (3)

[Claims] An inorganic spheroidized particle manufacturing apparatus comprising a melting chamber having a combustion device on a ceiling, a side wall formed of a refractory, and a cooling chamber having a water-cooled wall structure connected to the melting chamber. The melting chamber is divided into an upper band and a lower band, and a plurality of cooling gas supply means for jetting a cooling gas along inner wall surfaces of the upper band and the lower band are provided in a circumferential direction, and An apparatus for producing inorganic spheroidized particles, wherein the atmosphere temperature is maintained at 300 to 600 ° C. lower than the melting temperature of the inorganic raw material powder. 2. The apparatus for producing inorganic spheroidized particles according to claim 1, wherein the cooling chamber has a straight body portion at an upper portion and a funnel portion having a tapered shape at a lower end portion. 3. The cooling chamber according to claim 1, further comprising a duct having an outside air suction port at one end thereof and a suction device provided at the other end thereof with a suction means. Or the apparatus for producing inorganic spheroidized particles according to any one of the above items.