JP2002060226A - Glass melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass melting furnace which emphasizes the hot spring of molten glass to promote the convection of the molten glass to agitate it well and is capable of preventing heterogeneous glass in a half melted state of a surface layer on the side of a glass material feeding end from flowing to the side of a leading end fast. SOLUTION: In the glass melting furnace 10 having burners 6 installed at proper intervals on both-side wall surfaces toward an area 4 on the side of the leading end of the molten glass 2 from the area 3 on the side of the feeding end of the glass material 1 and a plurality of pairs of the first electrodes 7 which is installed at proper intervals in parallel to both-sidewall surfaces toward the area 4 on the side of the leading end from the area 3 on the side of the feeding end and whose energizing direction is the width direction of a furnace, a plurality of pairs of the second electrodes 8 whose energizing direction is the longitudinal direction of the furnace are arranged by a plurality of columns across the full length of the width direction of the furnace at proper intervals in a hot spring area 9 on the way to the area 4 on the side of the leading end from the area 3 on the side of the feeding end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an improvement in a glass melting furnace equipped with an oxyfuel burner.

[0002]

2. Description of the Related Art In a glass melting furnace, the main melting is performed by radiant heat from a burner. However, as the width of the furnace increases, the flame length of the burner becomes relatively shorter, and the glass material may not be heated uniformly. Occurs. In particular, since the burner flame length is shorter in the oxyfuel combustion type burner than in the air combustion type burner, the above phenomenon is likely to occur. Therefore, there has been proposed a method in which electrodes are arranged in the longitudinal direction of the kiln and heated by energization to assist the heating of the burner (see JP-A-11-100214).

[0003]

A glass melting furnace equipped with a conventional burner heats and melts a glass raw material mainly by radiant heat of a burner disposed at an appropriate interval on both side walls in a longitudinal direction. The electrodes for assisting this were arranged in the length direction of the kiln, and the direction of the current was set to the width direction of the kiln. However, in this case, a glass in a semi-molten state or incompletely molten state containing a heterogeneous component in the surface layer on the glass material input end side (hereinafter, referred to as a semi-molten state or the like in the present specification). It may flow quickly to the outlet end side, and there is a problem with the glass quality of the product (for example, bubbles, uneven meat,
Glass defects such as bumps and burrs).

Accordingly, the present invention emphasizes the hot spring of the molten glass, promotes the convection of the molten glass, performs good agitation, and generates a non-homogeneous glass such as a semi-molten state in the surface layer on the input side of the glass material. It is an object of the present invention to provide a glass melting furnace capable of preventing a rapid flow to a side.

[0005]

In order to achieve the above object, a glass melting furnace according to claim 1 of the present invention is arranged so that a region from an input end side of a glass raw material to a region from a discharge end side of a molten glass. Burners installed on both side walls at appropriate intervals,
In a glass melting furnace having a plurality of pairs of first electrodes which are installed at appropriate intervals in parallel with both side wall surfaces from the input end side region toward the lead-out end side region and the direction of current is the width direction of the kiln. In the hot spring region on the way from the region on the input end side to the region on the lead-out end side, a plurality of pairs of second electrodes whose energization direction is the length direction of the kiln are provided at appropriate intervals over the entire length in the width direction of the kiln. And arranged in multiple rows.

In the glass melting furnace according to the present invention, the second electrode arranged in the hot spring area melts the entire length of the furnace in the width direction of the furnace from the area on the input end side to the area on the lead-out end side. The hot spring of the glass can be emphasized, and in such a region where the hot spring of the molten glass is emphasized, the rising flow of the molten glass becomes vigorous, and the surface flow after the rising flows back to the region on the input end side. And a flow that advances to the area on the outlet end side, which promotes the convection of the molten glass and promotes good agitation, thereby further promoting homogenization and defoaming of the molten glass. In addition, due to the surface flow rising from the hot spring region and returning to the input end side, the inhomogeneous glass floating in the surface layer of the input end side region in a semi-molten state or the like flows to the output end side region. It can be prevented from flowing, thereby improving the glass quality.

In the glass melting furnace according to a second aspect of the present invention, the power supplied to the second electrode disposed in the hot spring region can be appropriately adjusted in the width direction of the furnace. I do. With this configuration, the upward flow of the molten glass can be made uniform over the entire length in the width direction of the kiln, and the glass quality can be further improved.

Although the present invention is effective for a glass melting furnace having a burner, the oxy-combustion type burner is particularly effective because the burner flame length is shorter than that of the air combustion type.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic vertical sectional side view showing a convection state of molten glass in a glass melting furnace according to the present invention, and FIG. 1B is a schematic view showing an energized state and an arrangement state of electrodes arranged in a hot spring region. FIG. 1C is a schematic plan view of the glass melting furnace, and FIG. 1C is a schematic plan view showing the entire configuration of the glass melting furnace according to the present invention.

1 (A), 1 (B) and 1 (C), 1 is a glass raw material, 2 is a molten glass, 3 is a region on the input end side, 4
Is the area on the outlet end side, 5 is the throat section, 6 is the burner, 7
Denotes a first electrode, 8 denotes a second electrode, 9 denotes a hot spring region, and 10 denotes a glass melting furnace.

As shown in FIG. 1A, the glass melting furnace 10 has a region 3 on the charging end side where the glass raw material 1 is charged.
And a region 4 on the leading end side where the molten glass 2 is led out to the molding portion through the throat portion 5, and a hot spring region 9 in the middle of these regions 3 and 4, and the whole is surrounded by a refractory material. It is a tank kiln.

In the present embodiment, the burner 6 exemplifies an oxyfuel combustion system. As shown in FIG. 1C, the burner 6 extends from a region 3 on the input end side of the glass raw material 1 to an outlet end side of the molten glass 2. Space on both side walls toward the area 4 of FIG.
Are arranged at equal intervals), are installed above the levels of the glass raw material 1 and the molten glass 2, and are configured to melt the glass mainly by the radiant heat of the burner 6. .

As shown in FIG. 1C, a plurality of pairs of the first electrodes 7 are formed at appropriate intervals in parallel with both side walls from the input end region 3 to the lead end region 4 in parallel with the wall surfaces. The electric current flows in the width direction of the kiln, and assists the burner 6 to heat the molten glass 2 by the Joule effect.

The second electrode 8 is shown in FIGS.
As shown in FIG. 3C, an appropriate interval (for example, tens of tens of A plurality of pairs are arranged in double rows at intervals of centimeters), the energization direction is the length direction of the kiln, and the supplied power can be adjusted appropriately in the width direction of the kiln.

The configuration of the embodiment of the glass melting furnace of the present invention is as described above. Next, the operation state will be described.
FIG. 1A shows a state in which the glass material 1 has reached a stable state after the start of the operation. In the region 3 on the input end side of the glass material 1, the glass material 1 is mainly melted. In the region 4 on the outlet end side, the molten glass 2 is homogenized, defoamed, and the like, and the throat portion 5 formed at a position lower than the liquid level.
The molten glass 2 that has been subjected to homogenization, defoaming and the like is led out to the molding section. In response to this derivation, the replenishment of the glass raw material 1 is automatically performed by the liquid level gauge. The newly supplied glass raw material 1 is floating on the molten glass 2 as shown in FIG. 1A, and is gradually melted. In the glass melting furnace 10, as shown in FIG. 1A, in the region 3 on the input end side with the hot spring region 9 interposed therebetween, the flow advanced through the furnace bottom rises at the hot spring region 9. As a result, a part thereof flows back toward the input end side area 3 and the remaining part advances toward the discharge end side area 4.

The molten glass 2 flowing back toward the input end region 3 melts the glass raw material 1 floating on the upper surface of the input end region 3 while pushing it back and flows down to the bottom of the kiln. Through the kiln bottom towards the hot spring region 9 and is raised again.

In the area 4 on the outlet end side, the molten glass 2 which rises and advances in the hot spring area 9 flows down to the kiln bottom near the outlet end, and a part thereof is led out from the throat section 5 to the forming section. The remaining part returns to the hot spring area 9 through the furnace bottom, merges with the molten glass 2 that has passed through the furnace bottom in the area 3 on the input end side, and is raised again, whereby the molten glass 2 is homogenized. And defoaming.

In the hot spring region 9, the second electrodes 8 are arranged at appropriate intervals in the width direction of the kiln, for example, at intervals of several tens of centimeters, and are energized in the length direction of the kiln. In addition, since the supply power can be appropriately adjusted in the width direction of the kiln, the hot spring of the molten glass 2 is emphasized, the convection of the molten glass 2 is promoted, and the molten glass 2 is well agitated. It is possible to prevent the inhomogeneous glass in a semi-molten state or the like floating on the surface layer from flowing quickly to the region 4 on the outlet end side. Thereby, the glass melting furnace 10 of the present invention can improve the glass quality by preventing foreign matters such as bubbles, uneven meat, bumps, burrs and the like from being mixed.

[0019]

According to the first aspect of the present invention, the hot spring of the molten glass can be emphasized over the entire length in the width direction of the kiln on the way from the area on the charging end side to the area on the outlet end side. However, in the region where the hot spring of the molten glass is emphasized, the upward flow of the molten glass becomes vigorous,
The surface flow after ascending is clearly divided into a flow that recirculates to the area on the input end side and a flow that advances to the area on the discharge end side, and promotes the convection of the molten glass on both sides to enable good stirring. This further promotes homogenization and defoaming of the molten glass, and furthermore, a semi-molten state that floats on the surface layer in the area on the input end side due to the surface flow rising from the hot spring area and returning to the input end side. Etc. can be prevented from quickly flowing to the region on the outlet end side, and the glass quality can be improved.

According to the second aspect of the present invention, the rising flow of the molten glass can be made uniform over the entire length of the kiln in the width direction, so that the glass quality can be further improved.

[Brief description of the drawings]

FIG. 1A is a schematic vertical sectional side view showing a convection state of molten glass in a glass melting furnace according to the present invention, and FIG. 1B is a schematic view showing an energized state and an arrangement state of electrodes arranged in a hot spring region. 1 is a schematic plan view of a glass melting furnace shown, and FIG. 2 (C) is a schematic plan view showing an entire configuration of a glass melting furnace according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass raw material 2 Molten glass 3 The area | region on the input end side 4 The area | region on the lead-out side 5 Throat part 6 Burner 7 1st electrode 8 2nd electrode 9 Hot spring area 10 Glass melting furnace

Claims (2)

[Claims] 1. A burner installed at an appropriate interval on both side walls from a region on the input end side of the glass raw material to a region on the output end side of the molten glass; It is installed at appropriate intervals parallel to both side walls,
In a glass melting furnace having a plurality of pairs of first electrodes whose energizing direction is set to the width direction of the kiln, the energizing direction is set to a hot spring area on the way from the input end side area to the lead-out end side area. A glass melting furnace characterized in that a plurality of pairs of second electrodes having a length direction are arranged in multiple rows at appropriate intervals over the entire length in the width direction of the furnace. 2. The glass melting furnace according to claim 1, wherein the power supplied to the second electrode arranged in the hot spring region can be appropriately adjusted in the width direction of the furnace.