JP2008285381A - Glass melting furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass melting furnace which is excellent in energy efficiency, can produce a desired and excellent glass melt in a short period of time, can be made compact, in other words, can be installed in a small space. <P>SOLUTION: The glass melting furnace for producing the glass melt from a glass raw material and an auxiliary raw material is provided, wherein a combustion assist gas having an oxygen concentration of ≥90 vol.% is supplied to an oxygen burner fitted downward to a ceiling wall on the upstream portion in the furnace and the oxygen burner is caused to burn downward, the glass raw material and the auxiliary raw material are supplied into the flame downward via a flow passage in the oxygen burner by gas conveyance, and while performing melting, the melt is stirred by supplying a gas for stirring from a gas supply tube fitted to a hearth wall on the upstream portion in the furnace, so that the melt is homogenized. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a glass melting furnace, and more particularly to an improvement of a glass melting furnace equipped with a burner as a heating source.

Conventionally, as a glass melting furnace for generating a glass melt from glass raw materials and auxiliary raw materials (hereinafter referred to as glass raw materials), a burner in which glass raw materials, etc., introduced into the furnace from the upstream portion of the furnace are attached to the side walls of the furnace It is known that it is dissolved in (see, for example, Patent Documents 1 to 3). However, in these conventional glass melting furnaces, glass raw materials and the like put into the furnace are melted by utilizing the in-furnace radiation by burning the burner. 1) When an oxygen burner is burned as a burner However, the energy efficiency is poor. 2) Various materials with different melting points are included in the glass raw materials to be put into the furnace. Among these, those having a low melting point dissolve quickly, Higher ones are slow to dissolve, so it is difficult to achieve homogeneous melting as a whole, and the time required for homogeneous melting is long. 3) Because there is a low-temperature material such as undissolved glass raw material above the glass melt produced in the furnace. There is a problem that the gas generated in the glass melt is difficult to escape and the time required for degassing is long. Conventional glass melting furnaces have a problem that energy efficiency is low and it takes a long time to produce a desired glass melt as desired, resulting in a large furnace.
JP-A-11-11953 Japanese Patent Laid-Open No. 11-11954 JP 2005-15299 A

  The problem to be solved by the present invention is that it is energy efficient, can produce a desired glass melt as desired in a short time, and can be downsized, in other words, can reduce installation space. It is in the place of providing a furnace.

  The present invention for solving the above problems is a glass melting furnace for generating a glass melt from a glass raw material or the like, and an oxygen burner is attached downward to the ceiling wall of the upstream part in the furnace, and the oxygen burner has an oxygen concentration A supporting gas of 90% by volume or more is supplied and a glass raw material or the like is supplied by gas conveyance, and a gas supply pipe is attached to the hearth wall of the upstream part in the furnace. A gas for stirring is supplied from a supply pipe, and the gas for stirring is supplied from the gas supply pipe while the oxygen burner is burned downward and a glass raw material is supplied downward into the flame and dissolved. The glass melting furnace is characterized in that the required glass raw material and the like are homogeneously melted by supplying.

  Similarly to the conventional glass melting furnace, the glass melting furnace according to the present invention also includes a burner as a heating source, and generates a glass melt from a glass raw material or the like. In the glass melting furnace according to the present invention, an oxygen burner is attached downward on the ceiling wall in the upstream part of the furnace. The oxygen burner is supplied with a combustion support gas having an oxygen concentration of 90% by volume or more, and glass raw materials and the like are supplied by gas transportation, and the oxygen burner is burned downward. Sometimes glass raw materials and the like are supplied downward into the flame and melted. As such an oxygen burner itself, a known one can be used. For example, an oxygen burner described in JP-A-8-312938, JP-A-2000-55340, JP-A-2000-103656, and the like can be used. Can be diverted. In these oxygen burners, the nozzle structure at the tip is directed from the center to the outer periphery, for example, a fuel supply nozzle, a primary combustion gas supply nozzle, an object to be processed (powder and particulate matter such as glass raw material), and a secondary Like the combustion support gas supply nozzle, a plurality of supply nozzles are concentrically arranged.

When the oxygen burner as described above is mounted downward on the ceiling wall in the upstream portion of the glass melting furnace and supplied with a supporting gas having an oxygen concentration of 90 vol% or more and burned downward, the temperature of the flame itself In addition, the flame also heats the molten metal surface of the glass melt produced in the furnace, and the amount of generated exhaust gas is small, so-called NO _X concentration in the exhaust gas is also low. When glass raw material or the like is supplied downward in such a flame, the glass raw material or the like dissolves in a very short time. In addition, at this time, the moisture of the glass raw material supplied downward in the high-temperature flame that burns downward evaporates all at once, and the glass raw material in the form of a carbonate compound decomposes and releases gas. The amount of gas generated in the glass melt produced in the furnace is significantly reduced.

  In the glass melting furnace according to the present invention, a gas supply pipe is attached to the hearth wall at the upstream part in the furnace, and the gas for stirring is supplied from the gas supply pipe to the upstream part in the furnace. . As described above, the required glass is obtained by supplying the stirring gas from the gas supply pipe to the upstream portion of the furnace while burning the oxygen burner downward and supplying the glass raw material or the like downward into the flame and melting it. The raw materials are homogeneously dissolved.

  In the glass melting furnace according to the present invention, a supporting gas having an oxygen concentration of 90% by volume or more is supplied to an oxygen burner mounted downward on the ceiling wall in the upstream part of the furnace, and a low volatility glass raw material is used. When the oxygen burner is burned downward, it is supplied by gas conveyance so that a low-volatile material such as a glass raw material is supplied downward into the flame to be melted, while in the furnace A raw material supply pipe is attached to the ceiling wall or side wall of the upstream part, and a high volatility glass raw material or the like is supplied from the raw material supply pipe by a conveyor transport or a gas transport. When a glass raw material or the like is supplied and melted downward in the flame, a raw material supply pipe is placed on the melt produced in the upstream portion of the furnace at the same time. Preferably, so as to dissolve by supplying of high volatility among such glass material with.

  Glass raw materials and the like can be broadly classified into those having high volatility, that is, those that are relatively volatile, and those having low volatility, that is, those that are relatively difficult to volatilize. Among the glass raw materials and the like, those having high volatility include those having a decomposition point or boiling point of 1500 ° C. or lower and a decomposition product having a boiling point of 1500 ° C. or lower, specifically, sodium carbonate, Examples thereof include sodium nitrate, sodium sulfate, arsenous anhydride, and antimony oxide. Further, among the glass raw materials, etc., those having low volatility are those other than those having high volatility as described above, specifically, silica, alumina, aluminum hydroxide, calcium carbonate, slaked lime, etc. It is done.

  Glass raw materials etc. are not divided into high volatile and low volatile ones, and high volatile ones together with low volatile ones are supplied by gas transportation to the oxygen burner as described above. When dissolved in a flame that burns downward, the high-volatility part of the high-temperature flame of the oxygen burner volatilizes and does not become a glass melt. Will supply a large amount to the oxygen burner in advance, resulting in a poor yield as a whole. In order to suppress the volatilization of the highly volatile glass raw materials and thus improve the overall yield, as described above, the low volatile ones of the glass raw materials are transferred to the oxygen burner by gas transportation. In order to promote the homogenization of both melts supplied separately from the raw material supply pipe, the high-volatility ones are melted in a high-temperature flame that is fed and burned downward. Stirring gas is supplied from a gas supply pipe attached to the floor wall.

  In the glass melting furnace according to the present invention, the oxygen burner, the raw material supply pipe, and the gas supply pipe are all attached to the furnace wall in the upstream part of the furnace. Although these are preferably attached to each other in terms of their properties, a raw material supply pipe is attached facing the lower part of the oxygen burner, and a gas supply is provided facing the oxygen burner. A tube is preferably attached. At the tip of a high-temperature flame that burns downward with an oxygen burner, a low-volatile solution of glass raw material is generated, and then a high-volatile material of glass raw material is supplied and dissolved. These are stirred and homogenized by the stirring gas supplied from the gas supply pipe directly below.

  As the stirring gas supplied from the gas supply pipe, air or an inert gas such as nitrogen gas can be used. Such a stirring gas can be supplied from room temperature to room temperature, but in order to prevent an undesirable solidified product of glass melt from being generated in the furnace by the supplied relatively low temperature stirring gas, It is preferable to supply the exhaust gas discharged from the melting furnace and / or the one heated by heat exchange with the furnace wall of the glass melting furnace, specifically, the one heated to 300 ° C. or higher. It is more preferable to supply. In addition, the stirring gas supplied from the gas supply pipe is preferably made to have a bubble diameter as large as possible in the glass melt in order to promote homogenization by stirring the glass melt. More preferably, the cell diameter is 2 mm or more on average.

  In the glass melting furnace which concerns on this invention, it is preferable to form the small pool which raised the hearth wall rather than the other part in the upstream part in a furnace. The upstream hearth wall where the small pool is formed is higher than the other parts, that is, the midstream and downstream hearth walls.In other words, the small pool is formed when viewed from the flat ceiling wall. The upstream hearth wall is shallow, and the other parts, that is, the midstream and downstream hearth walls are deep. The small pool is for temporarily storing the glass melt, and the temporarily stored glass melt is caused to flow out by overflow. When forming a small pool over the upstream part in the furnace, an oxygen burner is attached to the ceiling wall facing down the small pool, and a raw material supply pipe is attached to the ceiling wall or side wall facing down the small pool. A gas supply pipe is attached to the hearth wall forming a small pool. These preferred mounting positions are the same as described above. The small pool is for temporarily storing the glass melt and allowing the stored glass melt to flow out due to overflow. This further promotes homogeneous melting of the glass raw materials, etc., and degass the generated glass melt. Can be encouraged.

  In the glass melting furnace according to the present invention, when forming a small pool as described above in the upstream part of the furnace, an auxiliary oxygen burner is attached to the ceiling wall of the furnace facing the glass melt to be overflowed from the small pool, It is preferable that the auxiliary oxygen burner is burned without supplying glass raw material or the like, and the melt that is about to overflow from the small pool is heated by the flame. As a result, the generated glass melt can be urged to smoothly overflow and flow out of the small pool.

  In the glass melting furnace according to the present invention, whether or not the small pool is formed in the upstream part in the furnace, the glass melt in the furnace faces the ceiling wall on the downstream side of the upstream part in the furnace. It is preferable to attach the oxygen burner downward, burn the sub-oxygen burner downward without supplying glass raw material or the like, and heat the glass melt in the furnace by the flame. While promoting the degassing from the glass melt and reducing the combustion amount of the oxygen burner described above for some reason, as a result of insufficient heating of the glass melt in the furnace, the sub-oxygen burner should be turned downward. It is made to burn up so that the shortage can be compensated.

  According to the glass melting method of the present invention, when generating a glass melt from a glass raw material or the like, energy efficiency is good, a desired glass melt can be generated in a short time, and in addition, a small size, in other words, There is an effect that a glass melting furnace with a small installation space can be used.

  FIG. 1 is an overall view schematically showing a glass melting furnace according to the present invention partially in a longitudinal section. In the glass melting furnace 11 schematically shown in FIG. 1, an oxygen burner 21 is attached downward on the ceiling wall in the upstream portion of the furnace, and a secondary oxygen burner 22 is attached downward on the ceiling wall on the downstream side of the upstream portion. In addition, an exhaust port 31 is provided in the ceiling wall in the downstream part of the furnace. The oxygen burner 21 and the sub-oxygen burner 22 are attached to the ceiling wall via the cylinder mechanisms 24 and 25, and can be moved up and down, and between these tip portions and the molten metal surface of the glass melt A in the furnace. The distance is variable.

  The oxygen burner 21 has a plurality of supply nozzles in the order of a fuel supply nozzle, a primary combustion support gas supply nozzle, an object to be processed (glass raw material, etc.) supply nozzle, and a secondary combustion support gas supply nozzle. Consists of concentric circles. The oxygen burner 21 and the sub-oxygen burner 22 are supplied with combustion-supporting gas having an oxygen concentration of 90% by volume or more from the adsorption-type oxygen generator 41 through the combustion control unit 42, and also burn from the fuel tank 43. Fuel gas is supplied through the control unit 42. Further, a gas transport system 51 is connected to the oxygen burner 21 so that a low-volatile material such as a glass raw material is supplied by gas transport. A compressor 52 with a dryer is connected to the upstream side of the gas transfer system 51, and a raw material supply system 61 is connected in the middle thereof. The raw material supply system 61 includes a hopper 62 for storing a low-volatile material among glass raw materials, a quantitative cutting device 63 connected to the hopper 62, a vibrating sieve 64 connected to the quantitative cutting device 63, a vibrating sieve A fixed quantity supply device 65 connected to 64, and a crusher 66 that crushes the coarse material sieved by the vibrating sieve 64 and returns it to the upstream side of the vibrating sieve 64. An exhaust system 32 is connected to the exhaust port 31, and a heat exchanger 84, a cooling tower 33, a dust collector 34, a suction fan 35 and a chimney 36 are connected to the exhaust system 32 in this order.

  Further, a raw material supply pipe 71 is attached to the side wall of the upstream portion in the furnace so as to face directly below the oxygen burner 21, and a raw material supply system 72 is connected to the raw material supply pipe 71. The raw material supply system 72 includes a hopper 73 that stores highly volatile ones of glass raw materials and the like, and a screw conveyor 75 connected to the hopper 73.

  Further, a gas supply pipe 81 is attached to the hearth wall upstream of the furnace with the oxygen burner 21 facing directly above, and a gas supply system 82 is connected to the gas supply pipe 81. The gas supply system 82 includes a fan 83 for sending air and the heat exchanger 84 connected to the fan 83.

  In the glass melting furnace 11 of FIG. 1 described above, the fuel gas and the combustion supporting gas having an oxygen concentration of 90% by volume or more are supplied to the oxygen burner 21 mounted downward on the ceiling wall in the upstream portion of the furnace via the combustion control unit 42. Then, the oxygen burner 21 is burned downward, and the low volatility of the glass raw material or the like stored in the hopper 62 is transferred into the flame by gas transfer via the raw material supply system 61 and the gas transfer system 51. In the oxygen burner 21, it is supplied downward and melted through the above-mentioned workpiece supply nozzle, and the exhaust gas generated at this time is discharged from the exhaust port 31 through the exhaust system 32 and stored in the hopper 73. Among the glass raw materials and the like, highly volatile ones are supplied from the raw material supply pipe 71 through the raw material supply system 72 onto the glass melt immediately below the oxygen burner 21 and melted. And homogenized by stirring a glass melt by the oxygen burner 21 is heated by exhaust gas and heat exchange air from the gas supply pipe 81 through the gas supply system 82 for supplying faces just above at 84.

  FIG. 2 is an overall view schematically showing another glass melting furnace according to the present invention, partly in a longitudinal section and partly omitted. Here, for convenience of explanation, the same reference numerals as those in FIG. Further, illustration and description of the same components as those in FIG. 1 are omitted. In the glass melting furnace 11a schematically shown in FIG. 2, a small pool 12 is formed in the upstream part of the furnace. The small pool 12 is constructed by raising the upstream hearth wall 13 from the other part of the hearth wall downstream of the upstream pool wall and by setting up a weir 14 on the downstream side of the raised hearth wall 13. Is formed. In other words, when viewed from the flat ceiling wall, the upstream hearth wall 13 where the small pool 12 is formed is in a shallow place, and the other hearth wall in the other downstream side is in a deep place.

  An oxygen burner 21a is attached downward on the ceiling wall of the upstream portion in the furnace facing the small pool 12, and a secondary oxygen burner 22a is attached downward on the ceiling wall on the downstream side of the upstream portion, Further, an auxiliary oxygen burner 23 is attached to face the glass melt overflowing the weir 14 of the small pool 12, and an exhaust port 31a is provided in the ceiling wall at the downstream part in the furnace. The oxygen burner 21a, the sub-oxygen burner 22a, and the auxiliary oxygen burner 23 are attached to the ceiling wall via cylinder mechanisms 24a, 25a, 26, and can be moved up and down. The distance between the hot water surfaces of B and C is variable.

  The oxygen burner 21a, the sub-oxygen burner 22a, and the auxiliary oxygen burner 23 are supplied with a combustion-supporting gas having an oxygen concentration of 90% by volume or more, and with fuel gas. Further, the oxygen burner 21a is supplied with a low-volatile material such as a glass raw material by gas conveyance. Further, a raw material supply pipe 71a is attached to the side wall facing the small pool 12 in the upstream part of the furnace so as to face the lower part of the oxygen burner 21a. It comes to be supplied. Further, a gas supply pipe 81a is attached to the hearth wall 13 forming the small pool 12 upstream of the furnace with the oxygen burner 21a facing directly above, and the gas supply pipe 81a is in close contact with the side wall of the glass melting furnace 11a. The fan 83a for sending air to the base end part is connected.

  In the glass melting furnace 11a of FIG. 2 described above, fuel gas and combustion supporting gas having an oxygen concentration of 90% by volume or more are supplied to the oxygen burner 21a mounted downward on the ceiling wall facing the small pool 12 directly upstream of the furnace. Then, the oxygen burner 21a is burned downward, and a low-volatility glass raw material or the like is supplied into the flame downward through the above-described object supply nozzle in the oxygen burner 21a by gas conveyance. The exhaust gas generated at this time is dissolved and discharged from the exhaust port 31a, and the glass material B of the small pool 12 in the lower part of the oxygen burner 21a from the raw material supply pipe 71a is discharged from the raw material supply pipe 71a. At the same time, the small amount of air heated by exchanging heat with the side wall of the glass melting furnace 11a is heated from the gas supply pipe 81a to the oxygen burner 21a. And homogenized by stirring a glass melt B by supplying to the molten glass in B Le 12.

1 is an overall view schematically showing a part of a glass melting furnace according to the present invention in a longitudinal section. FIG. 3 is an overall view schematically showing another glass melting furnace according to the present invention, partially in a longitudinal section and partially omitted.

Explanation of symbols

11, 11a Glass melting furnace 12 Small pool 14 Weir 21, 21a Oxygen burner 22, 22a Sub-oxygen burner 23 Auxiliary oxygen burner 31, 31a Exhaust port 32 Exhaust system 41 Adsorption-type oxygen generator 42 Combustion control unit 51 Gas transport system 61, 72 Raw material supply system 62, 73 Hopper 63, 74 Fixed quantity cutting device 65 Fixed supply device 71, 71a Raw material supply pipe 81, 81a Gas supply pipe 83, 83a Fan 84 Heat exchanger

Claims (8)

  In a glass melting furnace for generating a glass melt from a glass raw material and an auxiliary raw material, an oxygen burner is attached downward on the ceiling wall in the upstream part of the furnace, and a combustion supporting gas having an oxygen concentration of 90% by volume or more is attached to the oxygen burner. Glass raw material and auxiliary raw material are supplied by gas conveyance, and a gas supply pipe is attached to the hearth wall in the upstream part of the furnace, and a gas for stirring is supplied from the gas supply pipe. And supplying the stirring gas from the gas supply pipe while the oxygen burner is burned downward and the glass raw material and auxiliary raw material are supplied downward into the flame and dissolved. A glass melting furnace characterized in that the required glass raw material and auxiliary raw material are homogeneously melted.   An oxygen burner mounted on the ceiling wall of the upstream part of the furnace facing downward is supplied with a combustion support gas with an oxygen concentration of 90% by volume or more, and low volatility among the glass and auxiliary materials is supplied by gas conveyance. Furthermore, a raw material supply pipe is attached to the ceiling wall or side wall of the upstream part in the furnace, and a highly volatile one of the glass raw material and the auxiliary raw material is supplied from the raw material supply pipe. The oxygen burner is burned downward and the low-volatile glass raw material and auxiliary raw materials are fed downward into the flame and melted. At the same time, it is generated in the upstream part of the furnace. By supplying a stirring gas from the gas supply pipe while supplying a high volatility of the glass raw material and auxiliary raw material from the raw material supply pipe onto the melt, Dissolve raw materials homogeneously Glass melting furnace according to claim 1 wherein as.   A small pool in which the hearth wall is raised from the other part is formed in the upstream part of the furnace, and an oxygen burner is formed on the ceiling wall facing down the small pool, and a ceiling wall facing down the small pool or The raw material supply pipe is attached to the side wall, and the gas supply pipe is further attached to the hearth wall forming the small pool. After the melt generated in the small pool is temporarily stored in the small pool, the small pool The glass melting furnace according to claim 2, wherein the glass melting furnace is caused to flow out of the tank by overflow.   Furthermore, an auxiliary oxygen burner is attached to the ceiling wall of the furnace facing the glass melt that is about to overflow from the small pool, and the auxiliary oxygen burner is burned without supplying glass raw materials and auxiliary raw materials to the flame. The glass melting furnace according to claim 2 or 3, wherein the melt that is about to overflow from the small pool is heated by the heating.   Further, a secondary oxygen burner is attached to the ceiling wall on the downstream side of the upstream portion of the furnace so as to face the glass melt in the furnace, and the secondary oxygen burner is not supplied with the glass raw material and the secondary raw material. The glass melting furnace according to any one of claims 1 to 4, wherein the glass melt is burned downward and the glass melt in the furnace is heated by the flame.   The glass melting furnace according to any one of claims 2 to 5, wherein a raw material supply pipe is mounted facing the lower part of the oxygen burner, and a gas supply pipe is mounted facing the oxygen burner. .   The stirring gas supplied from the gas supply pipe is heated by heat exchange with the exhaust gas discharged from the glass melting furnace and / or the furnace wall of the glass melting furnace. A glass melting furnace as described in one item.   8. The glass material and auxiliary material having high volatility include a substance having a decomposition point or boiling point of 1500 ° C. or lower and a decomposition product having a boiling point of 1500 ° C. or lower. A glass melting furnace as described in one item.

Images