JPS6410730B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a glass melting apparatus.

The amount of heating in a high-temperature heating furnace such as a glass melting furnace is controlled by radiant heat transfer from the flame, and in order to improve thermal efficiency, it is necessary to increase the amount of radiant heat transfer from the flame. It is also important that the flame length and furnace dimensions match.
For example, in a glass melting kiln, the flame length is considered optimal so that it covers the surface of the molten glass.

However, in conventional glass melting furnaces, heating is mainly performed only by combustion of liquid fuel, and in this case, it is difficult to adjust the brightness of the flame, that is, the amount of radiant heat transfer. Furthermore, the flame length can be adjusted to some extent by the amount of liquid fuel burned and the air ratio, but since the amount burned is inevitably determined by operating conditions such as throughput, the flame length can be adjusted freely. It is difficult to do so.

An object of the present invention is to solve the above-mentioned technical problems and provide a glass melting apparatus that can increase the amount of radiant heat transfer and appropriately adjust the flame length.

In the present invention, a gas pressure spray burner 1 having a substantially horizontal axis above the molten metal 52 is provided on side walls 50a and 50b of a glass melting furnace 50 that stores molten glass 52. Combustion air inlets 54a, 54b are formed in the side walls 50a, 50b. The gas pressure spray burner 1 has a flame opening 3 on its end surface 2a.
A nozzle member 5 is provided at the other end of the atomization passage 4, which extends in a straight line with one end communicating concentrically with the flame port, and the nozzle members 5 are formed at intervals in the circumferential direction. Liquid fuel is ejected from the nozzle hole 6 toward the atomization passage 4 via the liquid fuel supply pipe 7, and there is a hole in the middle of the atomization passage 4 directed toward the flame nozzle 3. A plurality of gas ejection holes 8 are provided diagonally and at intervals in the circumferential direction, gaseous fuel is supplied to the gas ejection holes 8, and gaseous fuel is supplied to the gas ejection holes 8 in the radial direction outward of the flame port 3 in the circumferential direction. A glass melting device characterized in that a plurality of air jet ports 10 are formed at intervals, and a very small amount of air is constantly jetted out from the air jet ports 10 to cool the vicinity of the end surface 2a. It is a device.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a simplified cross-sectional view of one embodiment of the invention. This glass melting furnace 50 is provided with gas pressure spray burners 1 facing each other on opposite side walls 50a and 50b, and the radiant heat transfer from the flame 55 of these gas pressure spray burners 1 melts the glass. molten metal 52 is heated. Generally, such a glass melting furnace is provided with a heat storage chamber (not shown) in order to effectively utilize combustion heat of fuel. In order to preheat the combustion air in the heat storage chamber, the gas pressure spray burners 1 provided on the side walls 50a, 50b are switched and fired at intervals of approximately 10 to 20 minutes, for example. The gas pressure atomizing burner 1 atomizes liquid fuel such as heavy oil with gaseous fuel such as city gas and co-combusts both.
Atomization of the liquid fuel is promoted by combustion of the gaseous fuel, and combustion with high brightness and good combustibility can be achieved.

FIG. 2 is a sectional view showing the gas pressure atomizing burner 1 of FIG. 1. FIG. A flame port 3 is formed on the end surface 2a of the main body 2 of the gas pressure spray burner 1, and a nozzle member 5 is provided at the other end of the atomization passage 4, which communicates concentrically with the flame port 3 and extends in a straight line. is provided. The nozzle hole 6 of the nozzle member 5 communicates with a liquid fuel supply pipe 7, and liquid fuel such as heavy oil is jetted from the nozzle hole 6 toward the atomization passage 4. A plurality of gas ejection holes 8 are formed in the middle of the atomization passage 4 and open obliquely toward the flame port 3. Gaseous fuel such as city gas supplied from the gas fuel supply pipe 9 is ejected from the gas jet port 8 into the atomization passage 4, whereby the liquid fuel is atomized and the gaseous fuel itself is also combusted to improve combustion efficiency. is improved.

A very small amount of air is always ejected from the air outlet 10. Combustion air is introduced from combustion air inlets 54a and 54b formed in side walls 50a and 50b above the position where gas pressure spray burner 1 is provided, respectively. These combustion air inlets 54a and 54b are connected to the flame 55 of the gas pressure spray burner 1.
It is formed to open diagonally downward at an angle α, that is, about 10 degrees, with respect to the extending direction of the burner 1, that is, with respect to the horizontal axis as shown in FIG. 1 of the gas pressure spray burner 1. . The amount of air ejected from the gas pressure spray burner 1 is about 0.5 to 2% of the combustion air introduced from the combustion air introduction ports 54a and 54b. When the gas pressure spray burner 1 is extinguished, only air is ejected from the plurality of air jet ports 10 formed on the end surface 2a, thereby causing the end surface 2a of the gas pressure spray burner 1 to reach a high temperature in the glass melting furnace 50. This prevents exposure and heating, and also prevents clogging of the flame port 3.

The main body 2 of the gas pressure atomizing burner 1 includes, in order from the inside to the outside, a nozzle holder 12 and an insert 13.
and an outer shell 14 are arranged concentrically. Outer shell 1
4, from one end on the left side to the other end on the right side of FIG. A through hole is drilled, which includes a conical hole 17 that becomes a diameter, a large diameter hole 18 that connects to the large diameter end of the conical hole 17, and a small diameter support hole 20 that connects to the large diameter hole 18 via a step surface 19. will be established. An air supply pipe 21 connected to an air supply source (not shown) is connected to a side wall of the outer shell 14 corresponding to the large diameter portion 18 .

The outer periphery of the insert body 13 is arranged in order from the left to the right in FIG.
and a conical portion 23 which is connected to the small diameter cylindrical portion 22 via the stepped surface 11, is spaced radially inward from the conical hole portion 17 of the outer shell 14, and becomes larger in diameter toward the right in FIG. , a cylindrical portion 24 connected to the large diameter end of the conical portion 23 at a position spaced radially inward from the large diameter hole 18 of the outer shell 14 and fitted into the support hole 20 of the outer shell 14; including. The insert 13 and the outer shell 14 are fixed to each other by welding at the right end in FIG.

FIG. 3 is a sectional view taken along the section line - in FIG. 2. An annular air passage 25 communicating with the air supply pipe 21 is formed between the inner circumference of the outer shell 14 and the outer circumference of the inner insert 13 . End surface 2a of outer shell 13
, a plurality of air outlets 10 (12 in the figure) are formed at equal intervals in the circumferential direction surrounding the flame port 3, and these air outlets 10 are communicated with the air passages 25, respectively. Each of the air jet ports 10 has axes that are inclined toward each other toward the left in FIG. 2 along the axis of the outer shell 14.

A through hole is formed concentrically in the insert 13, and the through hole is formed in order from the left to the right in FIG.
It includes a conical hole 27 that becomes larger in diameter toward the right in the figure, and a large diameter hole 28 that is connected to the large diameter end of the conical hole 27 via a stepped surface. An internal thread 29 is formed at the other end of the large diameter hole 28 on the right side in FIG.
The end of the gaseous fuel supply pipe 9 is provided with an external thread 30 that engages with the internal thread 29, and the gaseous fuel supply pipe 9 is screwed into the insert 13.

The outer periphery of the nozzle holder 12 has a conical portion 31 that abuts the inner surface of the conical hole portion 27 of the insert 13 in order from one end on the left side in FIG. 2 to the other end on the right side in FIG. and the large diameter hole 28 of the insert 13
Conical portion 3 at a position spaced radially inward from
A cylindrical portion 32 extending from the large diameter end of 1 toward the other end.
Equipped with. An annular gas passage 33 is formed between the inner surface of the large diameter hole 28 of the insert 13 and the cylindrical part 32, and the gas passage 33 communicates with the gaseous fuel supply pipe 9.

FIG. 4 is a sectional view taken along the section line - in FIG. 2. The conical part 31 of the nozzle holder 12 has
A plurality of (eight shown) grooves 34 extending along the axis
are formed at equal intervals in the circumferential direction. With the conical portion 31 in contact with the inner surface of the conical hole portion 27, the groove 34 forms a gas passage 35. One end of the gas passage 35 opens into the atomization passage 4 to form a gas ejection port 8, and the other end communicates with the gas passage 33.

The nozzle holder 12 includes, in order from one end to the other end, a small diameter hole 36, a holding hole 38 connected to the small diameter hole 36 via a step surface 37 perpendicular to the axial direction, and the holding hole. A through hole including a fitting hole portion 39 having a larger diameter than the portion 38 is formed. Holding hole 38
A cylindrical nozzle member 5 is fitted into the cylindrical nozzle member 5 . The liquid fuel supply pipe 7 is fitted into the fitting hole 39 , and the nozzle member 5 is held in the holding hole 38 by being pressed between the stepped surface 37 and the end of the liquid fuel supply pipe 7 .
Nozzle holes 6 twisted along the axis are bored in the nozzle member 5 at equal intervals in the circumferential direction. Therefore, the liquid fuel is ejected from the nozzle hole 6 while swirling.

With the nozzle holder 12 fitted into the insert 13, the small diameter hole 36, the conical hole 27, and the small diameter hole 26 are concentrically communicated to form the atomization passage 4.

When attaching the main body 2 to the liquid fuel supply pipe 7 and the gaseous fuel supply pipe 9 which are arranged in a concentric double-tube shape, first, the nozzle holder 12 with the nozzle member 5 fitted into the holding hole 38 is attached. into the end of the liquid fuel supply pipe 7. The liquid fuel supply pipe 7 is inserted into the fitting hole 39 until its end comes into contact with the nozzle member 5.
It will be inserted into. Next, the inner thread 29 of the inner insert 13, which is integral with the outer shell 14, is screwed into the outer thread 30 of the gaseous fuel supply pipe 9. At this time of screwing, the inner surface of the conical hole 27 of the insert 13 is connected to the nozzle holder 1.
The insert 13, which is integral with the nozzle holder 12 and the outer shell 14, is screwed until it abuts the conical portion 31 of the liquid fuel supply pipe 7 and the gaseous fuel supply pipe 9 at each end. is securely fixed.

Gas pressure spray burner 1 having the above-described configuration
During combustion, liquid fuel such as heavy oil is supplied from a liquid fuel supply source (not shown) through a liquid fuel supply pipe 7, and gas such as city gas is supplied from a gaseous fuel source (not shown) through a gaseous fuel supply pipe 9. Fuel is supplied. Liquid fuel is ejected from the nozzle hole 6 toward the atomization passage 4 . Further, the gaseous fuel is ejected from the gas ejection port 8 toward the atomization passage 4 via the gas passages 33 and 35. By jetting out the gaseous fuel, the liquid fuel is atomized in the atomization passage 4, jetted out from the flame port 3, and burned. Moreover, since the gaseous fuel is also combusted, the atomization of the liquid fuel is further promoted, and a good combustion state can be obtained without the flame spreading at the flame port 3. Therefore, the amount of heat radiated from the flame is increased, and since relatively low-temperature high-pressure air and steam are not introduced into the glass tank kiln, thermal efficiency is improved.

When extinguishing the gas pressure spray burner 1, the supply of liquid fuel and gaseous fuel from the liquid fuel supply pipe 7 and the gaseous fuel supply pipe 9 is stopped. Thereby, only cooling air is ejected from the air outlet 10 of the end face 2a via the air passage 25. The end face 2a is cooled by this cooling air, and the main body 2 is protected from the high temperature inside the glass tank kiln. Further, by ejecting air from the air outlet 10 toward the axis of the flame port 3, dust in the glass tank kiln is prevented from entering the flame port 3 and clogging it. Moreover, supply control of liquid fuel and gaseous fuel during extinguishing can be done by simply providing a control valve such as a solenoid valve in the middle of each pipe 7, 9, and no complicated control system is required.

In such a gas pressure spray burner 1, by adjusting the ratio of combustion charges between gaseous fuel and liquid fuel, the brightness of the flame, that is, the amount of radiant heat, the flame length, and the amount of NO _x generated can be controlled. .

Figures 5 and 6 show the experimental results conducted by the inventors.
7 and 7. In FIGS. 5 to 7, the gas addition ratio (%) indicates the ratio of the combustion amount of gaseous fuel to the total combustion amount of gaseous fuel and liquid fuel. In addition, in these experiments, the total combustion amount was 1,000,000 Kcal/H±8%, A heavy oil was used as the liquid fuel, and 13A city gas was used as the gaseous fuel. Furthermore, liquid fuel is 0.3~0.5Kg/
Sprayed at a pressure of cm ² . Note that in FIGS. 5 to 7, the shaded area 56 indicates a portion where the A heavy oil was poorly atomized.

In Fig. 5, the amount of radiant heat (Kcal/m ³ H) was measured at a point 2 m from the tip of the flame.
As is clear from FIG. 5, the amount of radiant heat can be increased when the ratio of the amount of combustion of gaseous fuel to the total amount of combustion is in the range of 20 to 60%. Also, in Figure 6, the flame length is 3 when the gas addition ratio is 33%.
m, and when the gas addition ratio was 50%, it was 2.5 m. Therefore, in a normal glass melting furnace, the flame length can be set to an appropriate value by setting the gas addition ratio to 20 to 60%.

In FIG. 7, it can be seen that the amount of NO _x generated is maximum when the gas addition ratio is in the range of 40 to 50%. Here, the amount of NO _x generated is shown in terms of O ₂ 15%. In FIG. 7, for comparison, the amount of NO _x generated when heavy oil A is sprayed with compressed air is shown by a broken line.
As is clear from FIG. 7, the amount of NO _x generated is reduced by atomizing liquid fuel with gaseous fuel. Moreover, the gas addition ratio is 40 to 50%.
By shifting from the range, the amount of NO _x generated can be further reduced.

As described above, according to the present invention, the amount of heat radiated from the flame is controlled by atomizing the liquid fuel with the gaseous fuel and adjusting the ratio of the amount of combustion of the gaseous fuel and the liquid fuel. The amount of radiant heat and the length of the flame can be adjusted appropriately, and the thermal efficiency of the glass melting pot can be improved. In particular, in the present invention, liquid fuel is atomized by jetting out gaseous fuel, and in this respect it is completely different from co-combustion burners such as those developed in Utility Model Application No. 55-19980, which improves the amount of radiant heat. Therefore, the length of the flame can be shortened.

Moreover, in the present invention, since a very small amount of air is always ejected from the air outlet 10, the vicinity of the end surface 2a of the gas spray burner is prevented from being overheated by the molten glass 52, and the flame outlet 3 This prevents blockage caused by dust, etc.

The combustion air inlets 54a, 54b formed in the side walls 50a, 50b of the glass melting furnace 50 are arranged at an angle of about 10 mm with respect to the direction in which the flame of the gas pressure spray burner 1 extends.
The combustion air therefore allows the gaseous fuel as well as the atomized liquid fuel to be smoothly combusted.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view of a gas pressure spray burner 1, FIG. Cross-sectional views taken from the cutting plane line in Figure 3, Figures 5 and 6
7 and 7 are graphs showing the experimental results, respectively. 1... Gas pressure spray burner, 50... Glass melting kiln, 55... Flame.

Claims (1)

[Claims] 1. Glass melting furnace 50 storing molten glass 52
A gas pressure spray burner 1 having a substantially horizontal axis above the molten metal 52 is provided on the side walls 50a, 50b of the gas pressure spray burner 1, and a combustion air inlet is provided in the side walls 50a, 50b above the gas pressure spray burner 1. 54
a, 54b are formed, and this combustion air inlet 5
4a and 54b are the flames 55 of the gas pressure spray burner 1;
The gas pressure spray burner 1 has a flame opening 3 on its end surface 2a.
A nozzle member 5 is provided at the other end of the atomization passage 4, which extends in a straight line with one end communicating concentrically with the flame port, and the nozzle members 5 are formed at intervals in the circumferential direction. Liquid fuel is ejected from the nozzle hole 6 toward the atomization passage 4 via the liquid fuel supply pipe 7, and there is a hole in the middle of the atomization passage 4 directed toward the flame nozzle 3. A plurality of gas ejection holes 8 are provided diagonally and at intervals in the circumferential direction, gaseous fuel is supplied to the gas ejection holes 8, and gaseous fuel is supplied to the gas ejection holes 8 in the radial direction outward of the flame port 3 in the circumferential direction. A glass melting device characterized in that a plurality of air jet ports 10 are formed at intervals, and a very small amount of air is constantly jetted out from the air jet ports 10 to cool the vicinity of the end surface 2a. Device.