JP3192007B2 - Glass melting method of glass melting furnace - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass melting furnace of the type in which a glass type is placed in a crucible and heated and melted, and more specifically, a glass melt discharged on a furnace floor for placing the crucible is discharged. The present invention relates to a method for discharging outflow glass from a glass melting furnace having a discharge path.

[0002]

2. Description of the Related Art In the above-mentioned glass melting furnace, a crucible is eroded by a high-temperature glass melt and broken, and the glass melt flows out into the furnace. This is particularly likely to occur in a calcined clay crucible having a high porosity and low erosion resistance to a glass melt. When the outflow of the glass melt occurs, the outflowing glass melt is fused to the furnace wall. However, it is not possible to remove the glass fused to the furnace wall by physical means such as shaving after cooling. This will cause damage to the wall, making it impossible to reuse it and increasing the cost. Therefore, when the outflow of the glass melt occurs, it is important to discharge the outflowed glass melt to the discharge path without fusing it to the furnace wall.
It is necessary to keep the fluidity of the glass melt high. As a solution, conventionally, it was considered to raise the temperature of the glass melt.However, for example, it is necessary to completely discharge the soda lime glass which occupies most of the glass types of the current ordinary molten glass. Requires a glass temperature close to 1500 ° C in view of its viscosity, and keeping the outflowing glass melt at such a high temperature for a long time not only increases the erosion of the refractory material in the hearth, but also It is not practical because it causes economical deterioration.

[0003]

SUMMARY OF THE INVENTION In short, no technique has been established in the past for discharging the outflowing glass melt without causing the above-mentioned disadvantages. An object of the present invention is to provide a technique capable of discharging a glass melt that has flowed rationally.

[0004]

The first aspect of the present invention is characterized in that the glass discharging method of the glass melting furnace is characterized in that the glass melt is brought into contact with the glass melt to increase the fluidity of the glass melt. The point is that the softener is sprayed. The glass discharging method of the glass melting furnace according to the second aspect of the present invention is characterized in that when the glass melt flows out of the crucible, the softening agent increases the fluidity of the glass melt by contacting with the glass melt. Is sprayed on the outflow glass.

[0005]

According to the method of the first aspect of the invention, when the glass melt flows out, the flowed glass melt comes into contact with the softening agent on the hearth, and the flowability is improved even at a low temperature. The discharge to the discharge path is performed smoothly. In addition, since it is not necessary to monitor the outflow of the glass melt, the management is easy. According to the method of the second invention, when the outflow of the glass melt occurs, by spraying the softening agent to the outflowing glass melt, the sprayed softening agent comes into contact with the outflowing glass melt, Even at low temperatures, the flowability of the outflowing glass melt is improved, and the outflowing glass melt can be smoothly discharged to the discharge path. In addition, since the softening agent is sprayed only at the time of outflow, a softening agent having a performance that can withstand high temperatures for a long time is not required, and the softening agent has good selectivity in terms of temperature.

[0006]

According to the present invention, therefore, the glass melt that has flowed out due to the destruction of the crucible can be smoothly discharged to the discharge path without causing the erosion of the furnace wall and the cost increase due to the high temperature, and the outflow thereof It has become possible to provide a glass discharging method capable of preventing an increase in cost due to non-reusability due to fusion of a glass melt to a furnace wall.

[0007]

Next, an embodiment will be described. [Embodiment 1] FIGS. 1, 2 and 3 show a glass melting furnace (crucible kiln), in which an upper wall portion 1, left and right side wall portions 2, a front wall portion 3, a rear wall portion 4, and a hearth. Each of the portions 5 is formed of a refractory material, and an opening is formed in the front wall portion 3 which also serves as a detachable door, so that the opening 6a of the crucible 6 faces the outside of the furnace.

As a crucible 6 for accommodating the glass x to be melted, a horizontal type (so-called cat crucible) having a mouth 6a formed in a horizontal direction is used, and the crucible 6 is placed on the hearth 5 via a base member 7 in the furnace.

Reference numeral 8 denotes a burner for heating the furnace which forms a combustion flame f in the furnace, 9 denotes a gas supply pipe for supplying a fuel gas g to the burner 8, and 10 denotes a combustion air a to the burner 8. An air supply pipe that is supplied under pressure by the fan 11. 12
Is an exhaust gas outlet for taking out the combustion exhaust gas in the furnace. Also, 1
Reference numeral 3 denotes an exhaust heat recovery heat exchanger that preheats the combustion air a sent to the burner 8 by the air supply pipe 10 by exchanging heat with combustion exhaust gas guided from the exhaust gas port 12 to the flue 14. The air pipe 10 is provided in the exhaust gas passage chamber 13a.
The tube type in which a is inserted is adopted.

Reference numeral 15 denotes a discharge path for drawing out the glass melt flowing out due to the breakage of the crucible 6 inside the furnace. deep. That is, the outflowing glass melt accumulates near the outlet of the discharge path 15. The glass melting furnace has a glass outflow detecting device for detecting the outflow of the glass melt. This glass outflow detecting device utilizes the fact that when the glass melt flows out, the outflowing glass melt flows down into the discharge path 15 and accumulates near the outlet. Is provided. The glass outflow detecting means is provided with a nozzle N for blowing out gas near the outlet of the discharge path 15, and the nozzle N
And a supply detection sensor 17 for detecting a gas supply state to the nozzle N. The nozzle N is mounted on the plug member 16. The gas supply means is provided at a portion of the combustion air supply pipe 10 downstream of the fan 11 to guide a part of the air in the combustion air supply pipe 10 to the nozzle N as a gas. Are connected by branching. That is, using the drive configuration for combustion of the burner 8,
It is configured to supply gas. If there is no glass melt near the outlet of the discharge path 15, the supply detection sensor 17 performs blowing of the gas from the nozzle N with low resistance. However, when the glass melt exists and the glass melt exists, When the circumference of the mouth of the tip is covered, the detection is performed by utilizing the fact that the gas blowing resistance increases, and specifically, the gas outlet pipe G
Noting that the pressures inside correspond, the gas outlet pipe G
It is a pressure gauge that detects the pressure inside. Thus, the glass outflow detecting means is configured to detect that the outflow of the glass melt has occurred when the pressure detected by the pressure gauge 17 is equal to or higher than a set value. Reference numeral 18 denotes an alarm which operates to detect the outflow of the glass melt by the pressure gauge 17 as the occurrence of crucible breakage in the furnace.

The burner 8 is of an inverted flame type in which a combustion flame is blown downward, and has a type in which the side surface of the burner forms a flat wall-shaped flame. The burner 8 is disposed on the furnace upper wall 1 near the rear wall. By doing so, a downward vertical wall-shaped combustion flame f in which the flame side faces continue in the furnace width direction and faces the crucible 6 from the back side thereof is formed along the wall surface of the rear wall portion 4.

On the other hand, the exhaust gas port 12
Is formed just above the crucible installation position in the furnace ceiling, and is located on the crucible side with respect to the combustion flame ejection position.

That is, in the above-described structure, the vertical wall-shaped combustion flame f uniformly raises the temperature in the furnace due to the spread of the flame side surface in the furnace width direction, and also uniformly heats the crucible 6 from the back side. The downward injection causes the tip of the combustion flame f or the subsequent high-temperature combustion exhaust gas flow to reach the lower part of the crucible 6 in a wide state in the furnace width direction. Exhaust gas outlet 1 located in
2, the high-temperature combustion exhaust gas in the wide state uniformly rises from the lower portion of the crucible to the crucible periphery, and reaches the exhaust gas port 12 while heating the crucible 6 during the rising process.

The target glass x at the bottom of the crucible is effectively heated by the crucible heating due to the rise of the high-temperature combustion exhaust gas from the lower part of the crucible to the periphery of the crucible, and the convection of the molten glass x in the crucible by heat is promoted. This convection causes the entire melt glass x to be in a homogeneously heated and melted state.

FIGS. 4, 5 and 6 show a burner structure,
19 is a slit-shaped ejection port 19a extending in the furnace width direction,
A flame port block formed with a nozzle insertion chamber 19b communicating therewith, 20 is a burner box having an air chamber 20a inside, 21 is a flat gas nozzle, and the air discharge port 20b of the burner box 20 is connected to the flame port block 19 Burner box 2 in a state where it is connected to nozzle insertion chamber 19b
0 and the flame port block 19, and the gas nozzle 21
The distal end side is inserted into the nozzle insertion chamber 19b, and the gas chamber section 21a on the proximal end side is located inside the air chamber 20a, and is housed in the communication section between the burner box 20 and the flame port block 19. .

Reference numeral 22 denotes a gas introduction pipe for introducing the fuel gas g from the gas supply pipe 9 into the gas chamber 21a in the burner box 20, and 23 denotes an air guide plate in the air chamber 20a. The combustion air a introduced into the air chamber 20a through the air supply port 20c at the side of the box is supplied to the burner box 20 by the air guide plate 23.
The air is discharged to the air discharge port 20b after being diffused to the entire peripheral portion of the inside, and once detoured to the rear end side of the burner box 20, thereby discharging the combustion air a from the air discharge port 20b. As a result, the state of the combustion flame ejection from the slit-shaped ejection port 19a is made uniform in the longitudinal direction of the ports 20b and 19a (corresponding to the furnace width direction).

At the leading edge of the flat gas nozzle 21, a slit-shaped gas passage 2 in the flat portion is provided from the gas chamber portion 21a.
A large number of gas holes 24 are formed in a line over the entire width of the nozzle to blow out the fuel gas g supplied through the nozzle 1b toward the jet port 19a of the flame port block 19, and each side surface near the leading edge of the flat gas nozzle 21 is formed. Are formed with a large number of sub-gas holes 25 that blow out the fuel gas g supplied through the slit-shaped gas passages 21b in a direction perpendicular to the side surfaces of the nozzles in the same manner over the entire width of the nozzles.

Each of the nozzle side surfaces is provided with a wind control projection 26 which is located near the upstream side of the row of auxiliary gas holes 25 in the direction of air flow in the nozzle insertion chamber 19b as an air ejection passage and is in an upright state with respect to the nozzle side surfaces. Are provided over the entire width of the nozzle, and a large number of air ventilation holes 26a are formed in the wind control projections 26 in two rows over the entire width of the nozzle.

That is, in this burner structure, the air flow passing outside the wind control projections 26 in the nozzle insertion chamber 19b serving as the air blowing path, the fuel gas blown out from the 25 rows of auxiliary gas holes and the air of the wind control projections 26 Three layers of a mixed flow with the air passing through the row of ventilation holes 26a and a fuel gas stream blown out from the row of gas holes 24 at the nozzle tip are formed. The slit-shaped outlet 19a in the block 19 is jetted into the furnace from the entire width in the longitudinal direction, whereby the downward vertical wall-shaped combustion flame f is formed along the wall surface of the furnace rear wall 4 as described above.

The method for discharging glass according to the first embodiment is as follows. The upper surface of the hearth 5, that is, the hearth surface 5 a is provided with a gradient for guiding the outflowing glass melt down to the discharge path 15, and reacts with the outflowing glass melt on the hearth surface 5 a. The softening agent p in the form of pellets for improving the fluidity of the glass melt is sprayed. Examples of the softener p include alumina, zirconia, zircon, magnesia,
Those obtained by mixing Portland cement with them can be mentioned. According to this discharging method, when outflow of the glass melt occurs, the outflowing glass melt contacts and reacts with the softener p to increase the fluidity, so that the discharge is performed smoothly.

[Second Embodiment] In the glass melting furnace of the first embodiment, the softener p shown in the first embodiment flows out based on the outflow detection of the glass outflow detecting device, that is, the notification of the alarm 18. Sprinkle on glass melt. In this case, as in the case of the first embodiment, the flowability of the outflowing glass melt is increased, and the discharge is performed smoothly.

[Another embodiment] Next, another embodiment will be described.

In the above-described embodiment, the softener p is in the form of pellets. However, the softener p may be in the form of powder or granules. It may be carried out without providing the glass outflow detecting device, and the detection type and structure of the glass outflow detecting device can be changed as appropriate. The specific structure of the burner 8 forming the downward vertical wall combustion flame f in the furnace can be changed in various ways. For example, instead of using the flat gas nozzle 21 as in the above-described embodiment, a plurality of gas nozzles are used. It is also possible to adopt a structure in which the gas is ejected in the same direction and arranged in a direction perpendicular to the gas ejection direction.

In the above-described embodiment, the vertical wall-shaped combustion flame f is formed in a flat plate shape. Instead, the vertical wall-shaped combustion flame f is formed into a curved plate shape surrounding the crucible 6 as shown in FIG. May be formed.

Further, the vertical wall-shaped combustion flame f is not limited to a complete series of flames strictly having no gap in the furnace width direction, and a plurality of downward-spouting combustion flames are arranged relatively densely in the furnace width direction. It is good also as thing of.

In the above-described embodiment, the gas supply means for supplying air for combustion as a gas has been described. However, the gas supply means includes a separate fan and supplies gas separately from combustion. It may be. In the above-described embodiment, the softening material p is provided to increase the fluidity of the glass melt, but the present invention may be carried out without the softening material p.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a furnace.

FIG. 2 is a sectional front view of the furnace.

FIG. 3 is a sectional view of the furnace in plan view.

FIG. 4 is an enlarged sectional view of a burner in a furnace side view direction.

FIG. 5 is a partially cutaway view of the burner in a furnace front view direction.

FIG. 6 is a front view of a gas nozzle tip.

FIG. 7 is a plan view showing another embodiment.

[Explanation of symbols]

 6 Crucible 5 Hearth p Softener

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-89419 (JP, A) JP-A-6-135725 (JP, A) Jiko 38-2560 (JP, Y1) (58) Field (Int.Cl. ⁷ , DB name) C03B 5/08 C03B 5/26 F27B 14/00

Claims (2)

(57) [Claims] A discharge path (1) for discharging a glass melt flowing out onto a hearth (5) for mounting a crucible (6).
In the glass melting furnace in which 5) is formed, a glass melting agent in which a softening agent (p) for increasing the fluidity of the glass melt by spraying the glass melt is sprayed onto the hearth (5). Furnace glass discharge method. 2. A discharge path (1) for discharging a glass melt flowing out onto a hearth (5) for mounting a crucible (6).
In the glass melting furnace in which 5) is formed, when outflow of the glass melt from the crucible (6) occurs, a softening agent (p) that reacts with the glass melt to increase the flowability of the glass melt. Is discharged into the glass melt, and the glass is discharged from the glass melting furnace.