JPH1111954A - Glass melting method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the melting efficiency of glass by positively utilizing the energy of the combustion flame of a burner for heating and melting glass and ceramics. SOLUTION: Granules made of a glass raw material are supplied into a combustion flame of an oxygen burner, and supplied into a furnace while being heated and melted by radiant heat transfer and convective heat transfer from the combustion flame.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for melting glass, and more particularly to a method for improving melting efficiency in a melting furnace for heating and melting glass and ceramics using a combustion flame of a burner as a heat source.

[0002]

2. Description of the Related Art Conventionally, in the glass manufacturing industry, various measures have been taken to achieve energy saving in glass melting furnaces, and tentative results have been obtained. For example, improving the heat retention and heat insulation of the melting furnace, reducing the amount of invading air, increasing the size of the heat storage chamber, improving the material and shape of the checker brick, and increasing the cullet addition rate to the raw materials, etc. Done,
As a result, the energy intensity can be reduced by about 20
%. Furthermore, at present, heat recovery efficiency is being further improved by preheating glass raw materials with exhaust gas, and by using an oxygen burner instead of a conventional air burner as a burner, the heat loss of the exhaust gas can be reduced. Attempts are being made to reduce nitrogen oxides (NOX) and improve the melting efficiency by raising the flame temperature.

[0003]

However, in the glass melting furnace, the glass material is heated and melted mainly by radiant heat transfer from the combustion flame of the burner and radiant heat transfer from the furnace inner wall heated by the combustion flame. Therefore, there is a problem that the thermal efficiency is lower than other industrial furnaces.

Accordingly, the present invention is to improve the thermal efficiency by positively utilizing the energy of the combustion flame of the oxygen burner,
It is an object of the present invention to provide a glass melting method capable of improving the glass melting efficiency.

[0005]

In order to achieve the above object, a method for melting glass according to the present invention comprises heating a glass raw material by using a combustion flame of an oxygen burner that uses oxygen or oxygen-enriched air as a combustion supporting gas as a heat source. In a method for melting glass to be melted, a glass material or a cullet or a powder containing at least a part of a mixed material thereof is supplied into a combustion flame of the oxygen burner, and is heated and melted in the combustion flame to form a glass melting furnace. It is characterized by being supplied inside.

Further, another configuration of the glass melting method of the present invention is such that a raw material charging section and a fining chamber are respectively connected before and after the melting chamber, and the glass raw material is heated and melted in the melting chamber. In the method of melting glass in a glass melting furnace having a plurality of oxygen burners for generating a combustion flame, during the combustion flame of at least one oxygen burner installed on the raw material charging section side of the melting chamber, the glass raw material or A cullet or a powder containing at least a part of a mixed material thereof is supplied, and the powder is heated and melted in a combustion flame and supplied into the melting chamber.

Furthermore, the present invention is characterized in that the oxygen concentration of the combustion supporting gas is 50% or more, and the powder is supplied to the oxygen burner by a carrier gas.

[0008]

1 and 2 show an embodiment of a glass melting furnace to which the method of the present invention is applied. FIG. 1 is a cross-sectional view of the glass melting furnace, and FIG. It is.
This glass melting furnace comprises a melting chamber 2 provided with six oxygen burners 1a to 1f, a raw material charging section 3 and a refining chamber 4 connected to the front and rear of the melting chamber 2, and a raw material charging section 3 is provided. Is heated and melted by the radiant heat transfer from the combustion flame of the oxygen burners 1a to 1f and the radiant heat transfer from the furnace inner wall heated by the combustion flame in the melting chamber 2, and then the refining chamber. 4. Homogenized and removed.

Of the six oxygen burners 1a to 1f,
The two oxygen burners 1a and 1b installed on the side close to the raw material charging section 3 have a fuel supply passage 5 for supplying propane gas, heavy oil, and the like, and a combustion supporting gas for supplying oxygen and oxygen-enriched air. A supply path 6 and a raw material powder supply path 7 for supplying a powder material containing at least a part of a glass raw material or cullet or a mixed material thereof are provided, and four burners 1 c on the refining chamber 4 side are provided. 1 to 1f, a fuel supply path 5 and a supporting gas supply path 6 are provided.

That is, the oxygen burner 1 on the raw material charging section side
Reference numerals a and 1b denote glass material supply for supplying powdery granules made of glass material into a flame generated by the combustion of the fuel from the fuel supply passage 5 and the supporting gas from the supporting gas supply passage 6. A raw material powder supply path 7 as a means is provided, and the powder supplied into the combustion flame from the raw material powder supply path 7 is
It is formed so as to be heated and melted by radiant heat transfer from the combustion flame and convective heat transfer.

As described above, by supplying the powdery granules made of the glass raw material into the combustion flame and melting them by heating, the energy of the combustion flame of the oxygen burners 1a and 1b can be reduced by the same radiant heat transfer as the conventional oxygen burner. It can be used not only for heating the glass raw material and the inner wall of the furnace, but also for directly heating and melting the glass raw material. Thereby, the melting efficiency of glass can be greatly improved, the amount of glass melt per unit heat receiving area of the melting furnace is improved, and productivity can be improved. In addition, when pure oxygen is used as the combustion supporting gas, the amount of generated nitrogen oxides (NOX) can be reduced as compared with the related art.

Further, by supplying and melting the raw material particles to the oxygen burners 1a and 1b on the side of the raw material input section having a large heat removal amount, the effect of improving the melting efficiency can be increased, and the state in which the glass is melted can be obtained. By providing ordinary oxygen burners 1c to 1f without the raw material powder supply path 7 on the fining chamber side, the fining effect of the glass is not adversely affected.

As the oxygen burners 1a and 1b provided with the raw material powder supply passage 7, a known oxygen burner for powder processing can be used. An oxygen burner having a triple pipe structure having a fuel flow path on the outside and a combustion supporting gas flow path on the outermost side can be used. In addition, in the vicinity of a normal burner nozzle having no raw material powder supply path, a nozzle for ejecting the raw material powder separately from the oxygen burner is provided, and the raw material powder is supplied from the nozzle into the combustion flame. It may be. The transfer of the raw material particles may be performed by mechanical means, but can be easily performed by transferring the raw material particles with an appropriate carrier gas, for example, oxygen gas or air.

As the raw material powder, a glass raw material, a cullet or a mixture of these materials obtained by crushing with a crusher or the like to several mm or less, preferably about 10 μm to 1 mm in average particle size can be used. At this time, if the powder is too large, not only the supply into the combustion flame becomes difficult, but also the residence time in the combustion flame becomes short due to the drop due to gravity, so that the powder may not be heated to a sufficient temperature. Conversely, if the powder is too small, it may be scattered. Further, the amount of the glass raw material to be supplied to the oxygen burner as powders may be the whole amount of the dissolved amount or a part thereof.

The fuel supplied to the oxygen burner may be any of gas, liquid, and solid. As the supporting gas, a gas containing oxygen at a concentration higher than the oxygen concentration of the atmosphere can be used. It is necessary to form a combustion flame having a temperature, a speed, and a flame length capable of dissolving the whole or most of the powdery granules made of the glass raw material in the generated combustion flame. The oxygen concentration in the supporting gas may be set in consideration of the state of the oxygen supply equipment, the state of generation of nitrogen oxides, and the like, and it is preferable to use a gas having an oxygen concentration of 50% or more. For example, FIG. 3 shows the relationship between the dissolution yield and the adiabatic theoretical maximum flame temperature with respect to the oxygen concentration in the combustion supporting gas when propane is used as the fuel. 50% from concentration
Up to the extent, the rate of improvement in the melting yield and flame temperature with the increase in oxygen concentration is large, and when the oxygen concentration becomes 50% or more,
It turns out that the improvement effect of both becomes small. In particular, the dissolution yield hardly increased beyond the oxygen concentration of 50%. Therefore, by using a gas having an oxygen concentration of 50% or more (oxygen-enriched air, low-pure oxygen, pure oxygen) as the supporting gas, the glass can be melted at a high melting yield.

[0016]

As described above, according to the present invention, the glass raw material is fed into the melting furnace while melting the glass raw material by positively utilizing the forced convection heat transfer of the combustion flame of the oxygen burner. Can be greatly improved,
The amount of glass melting per unit heat receiving area of the melting furnace is improved, and the productivity can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a glass melting furnace showing one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the same.

FIG. 3 is a graph showing a relationship between a melting yield and a flame temperature with respect to an oxygen concentration.

[Explanation of symbols]

1a to 1f: oxygen burner, 2: melting chamber, 3: raw material charging section, 4: fining chamber, 5: fuel supply path, 6: flammable gas supply path, 7: raw material powder supply path

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshiyuki Hagiwara Nippon Sanso Co., Ltd. 1-16-7 Nishi-Shimbashi, Minato-ku, Tokyo

Claims (4)

[Claims] 1. A glass melting method in which a glass material is heated and melted by using a combustion flame of an oxygen burner which uses oxygen or oxygen-enriched air as a combustion supporting gas, wherein at least one of a glass material, a cullet, and a mixed material thereof is used. A method for melting glass, comprising: supplying a particulate material containing a portion to a combustion flame of the oxygen burner; heating and melting the combustion particle in the combustion flame; 2. A raw material charging section and a refining chamber are respectively connected before and after the melting chamber, and a plurality of oxygen burners for generating a combustion flame for heating and melting the glass raw material are provided in the melting chamber. In a method of melting glass in a glass melting furnace, a powder containing at least a part of a glass material or a cullet or a mixed material thereof in a combustion flame of at least one oxygen burner installed on a material charging portion side of the melting chamber. A method for melting glass, comprising supplying granules, heating and melting the granules in a combustion flame, and supplying the melted particles into the melting chamber. 3. The method for melting glass according to claim 1, wherein the combustion supporting gas has an oxygen concentration of 50% or more. 4. The method for melting glass according to claim 1, wherein the powder is supplied to the oxygen burner by a carrier gas.