JP2004294042A - Combustion apparatus for heating furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion apparatus for a heating furnace, dispensing with a cooling fluid special for cooling a fuel jet, forming a firm and strong flame and restraining the generation of NOx. <P>SOLUTION: The fuel jet part Bn is provided with an outer cylindrical body 11 and an inner cylindrical body 12 coaxially formed so that the tip of the outer cylindrical body 1 is projected from the tip of the inner cylindrical body 12. A central jet passage 13 is formed in the cylinder of the inner cylindrical body 12, and an annular peripheral jet passage 14 is formed between the inner cylindrical body 12 and the outer cylindrical body 11. The parts forming the forward end sides of the respective peripheral jetting passages 14 in the outer peripheral surface of the inner cylindrical body 12 and the inner peripheral surface of the outer cylindrical body 11 are tapered as it goes toward the tip. The tip side of the peripheral jet passage 14 is constructed on a converging jet passage part 14g, and the inner peripheral surface of the projected part from the inner cylindrical body 12 in the outer cylindrical body 11 is formed as a cylindrical guide surface 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides a fuel ejection unit that ejects gas fuel into a furnace,
An oxygen-containing gas supply unit for supplying a combustion oxygen-containing gas to a combustion zone of gas fuel ejected from the fuel ejection unit from a combustion oxygen-containing gas supply point different from the gas fuel ejection point of the fuel ejection unit. The present invention relates to a combustion device for a heating furnace provided.
[0002]
[Prior art]
A combustion device for such a heating furnace (hereinafter sometimes simply referred to as a combustion device) discharges gas fuel into a furnace from a gas fuel discharge location by a fuel discharge portion, and a fuel discharge portion by an oxygen-containing gas supply portion. A combustion oxygen-containing gas is supplied from a combustion oxygen-containing gas supply point different from the gas fuel injection point to the combustion zone of the gas fuel ejected from the fuel ejection section, and the gas fuel and the combustion oxygen-containing gas are supplied to the combustion area. Are made to contact and burn in a furnace.
[0003]
Conventionally, in such a combustion apparatus, as shown in FIG. 8, a fuel ejection portion Bn is provided with a straight cylindrical outer cylindrical body 31 having an outer diameter and an inner diameter each constant in the axial direction and a nozzle 32 at a tip. The inner cylindrical body 33 having a straight cylindrical shape is provided with a coaxial core in a state where the tip of the outer tubular body 31 and the tip of the nozzle 32 are located at the same position in the axial direction. Between the tubular body 33 and the outer tubular body 31, an annular peripheral ejection path 34 for ejecting gas fuel straight along the axial direction is formed.
The nozzle 32 has a central ejection hole 32c which is located at the center thereof and ejects the gas fuel G straight along the axial direction of the nozzle 32, and an axial center of the nozzle 32 which is annularly arranged around the central ejection hole 32c. And a plurality of outer ejection holes 32s for ejecting the gas fuel G outwardly on the opposite side to the side.
Then, the gas fuel G is ejected straight from the central ejection hole 32c of the nozzle 32 along the axial direction of the nozzle 32, that is, along the axial direction of the fuel ejection portion Bn, and a plurality of outer lines arranged annularly around the central ejection hole 32c. The gas fuel G is ejected from the ejection holes 32s in a widening shape, and the gas fuel G is straightened along the axial center direction of the fuel ejection portion Bn from the annular peripheral ejection path 34 outside the plurality of outer ejection holes 32s arranged in an annular shape. The fuel G was ejected and burned.
Further, the gas fuel G is caused to flow through the peripheral ejection path 34 on the outer peripheral portion of the fuel ejection part Bn, and the fuel ejection part Bn is cooled by the flow of the gas fuel G. For example, a cooling fluid is supplied through the outer periphery of the fuel ejection portion Bn into the furnace, or a cooling jacket is provided on the outer periphery of the fuel ejection portion Bn, and a cooling fluid such as water flows through the cooling jacket. Thus, the fuel jetting portion Bn can be cooled without flowing a cooling-specific fluid. (For example, refer to Patent Document 1).
[0004]
[Patent Document 1]
JP-A-2002-286225
[0005]
[Problems to be solved by the invention]
However, in the conventional combustion device, the gas fuel is ejected straight from the peripheral ejection path along the axial direction of the fuel ejection part, so that the gas fuel ejected from the peripheral ejection path is easy to spread, and Since the gas fuel is ejected from the plurality of outer ejection holes arranged in an annular shape of the nozzle in a divergent shape, the gas fuel flow ejected from the outer ejection holes in a divergent manner is ejected from the surrounding ejection path. The spread of the used gas fuel will be promoted.
Accordingly, the flow of gas fuel ejected from the fuel ejection portion is generally weakened and easily diffused, so that the generated flame is weakened, that is, the flame is weakened. By the way, if the flame of the flame becomes weaker, the flame is easily swept by the atmosphere in the furnace, the direction of the flame formation becomes unstable, and the flame easily contacts the furnace wall, so that the furnace wall is easily damaged. However, it is not preferable in terms of improving the durability of the furnace.
[0006]
Further, in such a combustion apparatus, in accordance with the type of the object to be heated, the amount of combustion is the same, that is, while the amount of gas fuel ejected from the fuel ejection section is the same, the length of the flame is varied. Therefore, it may be necessary to change the temperature distribution in the furnace.
In changing the length of the flame in this manner, in the conventional combustion apparatus, the diameter of the central ejection hole of the nozzle is made different to cope with the change.
That is, when the length of the flame is shortened, the diameter of the central ejection hole is made small, and the ejection speed of the gas fuel from the central ejection hole is increased, so that the combustion by the ejector action by the fast gas fuel flow. By promoting the inhalation of oxygen-containing gas, the gas fuel is burned quickly to shorten the length of the flame.
On the other hand, when increasing the length of the flame, the suction of the oxygen-containing gas for combustion is reduced by increasing the diameter of the central ejection hole and decreasing the ejection speed of the gas fuel from the central ejection hole. The gas fuel is slowly burned to increase the length of the flame.
However, conventionally, the length of the flame is changed by changing the ejection speed of the gas fuel from the fuel ejection portion, but when the ejection speed of the gas fuel is increased to shorten the length of the flame. In addition, since the suction of the oxygen-containing gas for combustion is promoted and the combustion of the gaseous fuel is accelerated, the problem that the flame temperature is increased and the generation amount of NOx is increased is caused.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to form a strong flame and generate NOx while eliminating the need for a dedicated cooling fluid for cooling a fuel ejection portion. It is an object of the present invention to provide a combustion device for a heating furnace, which can suppress the occurrence of the heat.
[0008]
[Means for Solving the Problems]
[Invention of claim 1]
The combustion device for a heating furnace according to claim 1, a fuel ejection unit that ejects gas fuel into the furnace,
An oxygen-containing gas supply unit for supplying a combustion oxygen-containing gas to a combustion zone of gas fuel ejected from the fuel ejection unit from a combustion oxygen-containing gas supply point different from the gas fuel ejection point of the fuel ejection unit. A combustion device for the provided heating furnace,
The fuel ejection portion is provided with an outer cylindrical body and an inner cylindrical body in a coaxial shape with a tip of the outer tubular body protruding from a tip of the inner tubular body, and a cylinder of the inner tubular body. Is configured to form a central ejection path within and form an annular peripheral ejection path between the inner cylindrical body and the outer cylindrical body,
The outer peripheral surface of the inner cylindrical body and the inner peripheral surface of the outer cylindrical body, each of which forms the tip side of the peripheral ejection path are formed in a tapered shape having a smaller diameter toward the tip side, and The leading end side is configured as a convergent ejection path portion that ejects gas fuel so as to converge from the outer peripheral side of the inner cylindrical body toward the axis center,
The inner peripheral surface of the protruding portion of the outer cylindrical body from the inner cylindrical body has the same diameter or substantially the same diameter as the outer peripheral edge from the outer peripheral edge of the annular peripheral jet at the tip of the convergent jet path portion. It is characterized in that it is configured so as to extend forward and form a cylindrical guide surface for guiding gas fuel ejected from the central ejection path and the peripheral ejection path.
That is, gas fuel is ejected straight from the central ejection path along the axis of the fuel ejection section, and the gas fuel is directed toward the axis of the fuel ejection section from the convergent ejection path portion on the tip side of the peripheral ejection path. The gas fuel is ejected so as to converge, and the gas fuel ejected from the central ejection path and the peripheral ejection path is guided by the cylindrical guide surface.
In other words, gas fuel is jetted from the converging jet channel portion so as to converge toward the gas fuel flow jetted straight from the central jet channel, and the cylindrical guide surface is formed at the end of the convergent jet channel portion. It is provided so as to extend forward from the outer peripheral edge of the annular peripheral outlet with the same diameter or substantially the same diameter as the outer peripheral edge, and ejects from the central ejection path and the convergent ejection path portion at the cylindrical guide surface. The gas fuel is guided so as to flow forward while the spread is regulated, and the gas fuel ejected from the convergent ejection path portion is promoted to converge toward the gas fuel flow ejected from the central ejection path. As a result, gas fuel is jetted from the fuel jetting section with great vigor while being suppressed from spreading as a whole, and a strong flame is formed.
Further, the gas fuel is caused to flow through the peripheral ejection path on the outer peripheral portion of the fuel ejection part, and the fuel ejection part is cooled by the flow of the gas fuel. Can be cooled.
When the length of the flame is changed, the cross-sectional area of the flow path of the central ejection path and the cross-sectional area of the flow path of the convergent ejection path portion are made the same or substantially the same, and the ejection speed of the gas fuel from the fuel ejection section is made the same. Alternatively, it is possible to cope with this by making the angle (hereinafter, sometimes referred to as an inward angle) facing the axis side of the fuel ejection portion in the ejection direction of the convergent ejection path portion substantially the same, while maintaining the same.
That is, the flame length can be shortened by increasing the inward angle of the jetting direction of the convergent jet path portion, and conversely, by decreasing the inward angle of the jetting direction of the convergent jet channel portion, the flame can be reduced. Can be lengthened.
In changing the length of the flame in this way, it is possible to change the length of the flame while making the ejection speed of the gas fuel from the fuel ejection portion the same or substantially the same, so that the gas fuel can be changed. It is possible to avoid such a problem that the amount of generated NOx increases as in the related art described above due to the increase in the ejection speed.
Accordingly, there is provided a combustion apparatus for a heating furnace, which can form a strong flame and suppress generation of NOx without requiring a dedicated cooling fluid for cooling a fuel ejection portion. Now you can do it.
[0009]
[Invention of claim 2]
The combustion device for a heating furnace according to claim 2 is the combustion device according to claim 1, wherein a length of the cylindrical guide surface is shorter than a diameter of an outer peripheral edge of the peripheral spout, and a length of the peripheral spout. The feature is that it is configured to be longer than the diameter of the inner peripheral edge.
That is, the inventor of the present invention has diligently studied and made the length of the cylindrical guide surface shorter than the diameter of the outer peripheral edge of the peripheral outlet at the end of the convergent discharge path portion, and of the peripheral outlet. When set to be longer than the diameter of the inner peripheral edge, the gaseous fuel ejected from the convergent ejection path portion is discharged from the central ejection path at the guide surface without unnecessarily increasing the length of the cylindrical guide surface. It has been found that it can be guided to converge effectively towards the jetted gaseous fuel flow.
In other words, if the length of the cylindrical guide surface is shorter than the diameter of the inner peripheral edge of the peripheral jet, the length of the guide surface is too short and the gas fuel ejected from the convergent jet path is guided so as to converge. On the other hand, if the length of the cylindrical guide surface is made longer than the diameter of the outer peripheral edge of the peripheral jet, the guide operation is not so strong, and on the contrary, the length of the guide surface becomes too long. The disadvantage that the size of the fuel ejection section is increased becomes significant.
Therefore, it is possible to provide a preferable specific configuration for implementing the present invention while reducing the size of the fuel ejection section.
[0010]
[Invention of claim 3]
According to a third aspect of the present invention, there is provided a combustion apparatus for a heating furnace, wherein the fuel ejection section is replaceable with a fuel supply section that supplies gas fuel to the fuel ejection section. ,
It is characterized in that a plurality of fuel ejection portions having different angles toward the axis in the ejection direction of the convergent ejection path portion are provided as the fuel ejection portions.
That is, the length of the flame to be formed can be changed by replacing the fuel ejection portion attached to the fuel ejection portion with a fuel ejection portion having a different inward angle in the ejection direction of the convergent ejection path portion.
In other words, as described in the first aspect of the present invention, the length of the flame can be changed by changing the inward angle of the jetting direction of the convergent jetting path portion. The fuel supply unit is configured so that it can be replaced, and a plurality of fuel ejection units having different inward angles of the convergent ejection path portion are prepared as the fuel ejection unit, so that only the fuel ejection unit is replaced. It will be possible to change the length of the flame.
By the way, the fuel ejection part is constituted so as to be integrally provided with a fuel supply part for supplying gaseous fuel to the fuel ejection part. It is conceivable to prepare a plurality of fuel ejection sections with different angles and replace the fuel ejection section integrally with the fuel supply section so that the length of the flame can be changed. Can be However, in this case, it is necessary to prepare a plurality of expensive fuel ejection sections integrally provided with a fuel supply section, so that the cost of the combustion device rises.
Therefore, the length of the flame can be changed while reducing the cost.
[0011]
[Invention of claim 4]
A combustion apparatus for a heating furnace according to claim 4, according to any one of claims 1 to 3, wherein a ratio between a gas fuel ejection amount from the central ejection passage and a gas fuel ejection amount from the peripheral ejection passage. The characteristic feature is that an ejection amount ratio adjusting means for adjusting the pressure is provided.
That is, the length of the flame can be changed by adjusting the ratio between the amount of gas fuel ejected from the central ejection path and the amount of gas fuel ejected from the peripheral ejection path by the ejection amount ratio adjusting means.
In other words, when the ejection amount ratio adjusting means is adjusted to increase the ejection amount from the central ejection passage, the ejection speed of the gas fuel from the central ejection hole is increased, and the suction of the oxygen-containing gas for combustion by the ejector action is prevented. As the flame is accelerated, the length of the flame is shortened. Conversely, if the amount of gas ejected from the central ejection passage is adjusted to be small, the ejector action is weakened and the suction of the oxygen-containing gas for combustion is weakened. Becomes longer.
By the way, if the ejection amount from the central ejection passage becomes too large and the ejection speed of the gas fuel from the central ejection hole becomes too fast, the generation amount of NOx increases. The adjustment range is restricted to a narrow range where the amount of generated NOx does not become too large, and the adjustment of the flame length in a wide range is performed when the inward angle of the convergent jet path portion differs from the fuel jet portion. It is preferable to respond by changing to.
Therefore, the length of the flame can be finely adjusted while suppressing the generation of NOx.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is applied to a combustion apparatus for a glass melting furnace as a heating furnace will be described with reference to the drawings.
First, a glass melting furnace provided with a combustion device will be described.
As shown in FIGS. 1 and 2, the glass melting furnace includes a melting tank 2 having a rectangular shape in a plan view at a lower portion in a furnace body 1, and a furnace wall for installing a combustion device on one side of the melting tank 2. 4, a combustion device is provided so as to blow gas fuel G into the furnace 3 and form a flame F above the melting tank 2 in a state facing the furnace wall 4 facing the furnace wall 4 for installing the combustion device. It is configured in.
[0013]
At the end on the combustion device installation side of the furnace wall 4 connected to the lateral end of the furnace wall 4 for installing the combustion device, a glass material is supplied in a direction substantially orthogonal to the direction of gas fuel ejection from the combustion device. An opening 4i is provided, a work tank 9 is provided outside the furnace wall 4 facing the furnace wall 4 for installing the combustion device, and a melting tank 2 is provided on the furnace wall 4 between the work tank 9 and the melting tank 2. An opening 4e for communication between the melting tank 2 and the work tank 9 is formed at the hearth of the melting tank 2 to form a so-called end port.
That is, the glass raw material in the melting tank 2 is melted by the flame F formed by the combustion device, the glass raw material is charged into the melting tank 2 through the inlet 4i, and the glass raw material is directed toward the opening 4e. It is configured to melt while flowing in a meandering manner, and to lead clean molten glass to the work tank 9 through the opening 4e of the hearth.
[0014]
The combustion device will be described in more detail. The combustion device includes a pair of combustion units provided side by side on the furnace wall 4 for installing the combustion device, and the pair of combustion units is operated for a predetermined time (for example, Every 15 to 30 minutes), so-called alternating combustion is performed.
Each of the pair of combustion units is provided with two gas burners B for injecting the gas fuel G into the furnace 3 and one air port 5 located above the gas fuel ejection point of the gas burner B, from the gas burner B. A single air supply path 6 serving as an oxygen-containing gas supply unit for supplying combustion air A obliquely downward as the oxygen-containing gas for combustion to the combustion region of the gas fuel G to be ejected, It is configured as a port type, and further includes a single heat storage chamber 8 that communicates with the air supply path 6 and has a heat storage material, and is configured as a heat storage type. The air port 5 corresponds to a combustion oxygen-containing gas supply location different from the gas fuel ejection location.
[0015]
The gas burners B of the pair of combustion units are configured to alternately switch between a spouting state in which the gaseous fuel G is spouted and a spouting stopped state in which the spouting of the gaseous fuel G is stopped at regular intervals. The air supply path 6 of the combustion section is preheated to a high temperature (about 1000 to 1200 ° C.) by the heat storage material through the heat storage chamber 8 through the air supply path 6 of the combustion section toward the gas burner B in the jetting state. The combustion air A is supplied from the air port 5 to the furnace 3 through the air port 5, and the air supply path 6 of the combustion section toward the gas burner B in the jetting stopped state. The combustion gas E of No. 3 is discharged, and the exhaust heat of the combustion exhaust gas E is switched to an exhaust state in which the heat is stored in the heat storage material.
Then, the gas burners B of the pair of combustion sections are alternately switched to the ejection state and the ejection stop state at regular intervals, and the air supply path 6 of the pair of combustion sections is switched between the supply state and the exhaust state. The state is switched to the state, and the pair of combustion sections are alternately burned as described above. FIGS. 1 and 2 show a state in which the right burning part is burning and the left burning part is extinguished.
[0016]
Hereinafter, the gas burner B will be described.
As shown in FIGS. 3, 5 and 6, the gas burner B includes a fuel ejection section Bn for ejecting the gas fuel G into the furnace 3, and a fuel supply section Bs for supplying the gas fuel G to the fuel ejection section Bn. The fuel ejection section Bn is configured to be freely replaceable with respect to the fuel supply section Bs.
[0017]
As shown in FIGS. 4 to 6, the fuel ejection portion Bn of the gas burner B is configured such that a cylindrical outer cylindrical body 11 and an inner cylindrical body 12 The central ejection passage 13 is provided coaxially with the inner cylindrical body 12 protruding from the front end and the rear end of the inner cylindrical body 12 projecting from the rear end of the outer cylindrical body 11. The outer peripheral surface of the inner cylindrical body 12 and the inner peripheral surface of the outer cylindrical body 11 are formed so as to form an annular peripheral ejection path 14 between the inner cylindrical body 12 and the outer cylindrical body 11. The portions 12g and 11g forming the distal end side of each peripheral ejection path 14 are formed in a tapered shape having a smaller diameter toward the distal end side, and the distal end side of the peripheral ejection path 14 is supplied with the gas fuel on the outer peripheral side of the inner cylindrical body 12. From the fuel injection portion Bn so as to converge toward the axis P (corresponding to the axis of the outer cylindrical body 11 and the inner cylindrical body 12 in the coaxial state). And the inner peripheral surface of the protruding portion of the outer cylindrical body 11 from the inner cylindrical body 12 is formed from the outer peripheral edge of the annular peripheral outlet 15 at the tip of the convergent jet path portion 14g. It is configured so as to extend forward with the same diameter as the outer peripheral edge and form a cylindrical guide surface 16 for guiding gas fuel ejected from the central ejection passage 13 and the peripheral ejection passage 14.
[0018]
As the fuel ejection portion Bn, a plurality of fuel ejection portions Bn having different angles toward the axis P in the ejection direction of the convergent ejection path portion 14g, that is, different inward angles α, are provided, and among the plurality of fuel ejection portions Bn, Either one is selected and attached to the fuel supply section Bs. Incidentally, the inward angle α of the convergent ejection path portion 14g of the fuel ejection portion Bn shown in FIG. 5 is larger than the inward angle α of the convergent ejection passage portion 14g of the fuel ejection portion Bn shown in FIG.
[0019]
The inner cylindrical body 12 and the outer cylindrical body 11 will each be described based on FIGS. 5 and 6.
The inside of the inner cylindrical body 12 is formed such that the inner diameter at the front end side is smaller than the inner diameter at the rear end side, the rear end side of the central ejection path 13 is formed into a large diameter portion, and the front end side is formed into a small diameter portion, The gas fuel is ejected from the central outlet 17 at the tip through the small-diameter portion of the central outlet 13 while applying pressure at the large-diameter portion of the central outlet 13. At the rear end of the inner cylindrical body 12, a female screw portion 12s for connecting to a fuel supply portion Bs described later is formed. In addition, the distal end portion of the outer peripheral surface of the inner cylindrical body 12 is formed as the aforementioned tapered portion 12g.
The above-mentioned tapered portion 11g is formed at the intermediate portion of the inner peripheral surface of the outer cylindrical body 11 in the direction of the axis P, and the inner peripheral surface extending from the tip of the tapered portion 11g to the tip of the tapered portion 11g. A cylindrical guide surface 16 is formed so as to extend to the tip of the outer cylindrical body 11 with the same diameter as that of the outer cylindrical body 11. A female screw portion 11s for connecting to a fuel supply portion Bs described later is formed at the rear end of the outer cylindrical body 11.
[0020]
Then, the inner cylindrical body 12 and the outer cylindrical body 11 are positioned such that the tip of the inner cylindrical body 12 and the tip of the tapered portion 11g of the inner peripheral surface of the outer cylindrical body 11 are at the same position in the axis P direction. In a state where it is disposed coaxially in a position, it is configured to be connected to a fuel supply portion Bs described later, and a central ejection path 13 is formed in the cylinder of the inner cylinder 12, An annular peripheral ejection path 14 is formed between the inner cylindrical body 12 and the outer cylindrical body 11, and a tapered portion 12g on the outer peripheral surface of the inner cylindrical body 12 and a tapered portion 11g on the inner peripheral surface of the outer cylindrical body 11 are formed. Between the peripheral jet 14 and the convergent jet channel portion 14g, and further extends forward from the outer peripheral edge of the annular peripheral jet port 15 at the tip of the convergent jet channel portion 14g with the same diameter as the outer peripheral edge. The inner peripheral surface of the outer cylindrical body 11 is formed as a cylindrical guide surface 16.
[0021]
Further, the tapered portion 12g on the outer peripheral surface of the inner cylindrical body 12 and the tapered portion 11g on the inner peripheral surface of the outer cylindrical body 11 are formed so that the interval between them becomes smaller toward the distal end side. The convergent ejection path portion 14g of the ejection path 14 is configured such that the cross-sectional area of the passage becomes narrower toward the distal end. Then, gas fuel is applied through a convergent jet path portion 14g by applying pressure, and is jetted from the peripheral jet port 15 at the tip thereof so as to converge vigorously toward the axis P side.
The tapered portion 12g of the outer peripheral surface of the inner cylindrical body 12 and the tapered portion 11g of the inner peripheral surface of the outer cylindrical body 11 have different angles facing the axis P, so that the peripheral ejection path 14 is formed. The inward angle α of the convergent jet path portion 14g is made different.
[0022]
The diameter of the outer peripheral edge of the peripheral outlet 15 (that is, the diameter of the cylindrical guide surface 16) is a, the diameter of the inner peripheral edge of the peripheral outlet 15 is b, the diameter of the central outlet 17 is c, and the diameter of the peripheral outlet 14 is Assuming that the length of the convergent jet path portion 14g in the direction of the axis P is Y, the inventor of the present invention has diligently studied and found that the diameter a of the outer peripheral edge of the peripheral jet 15 and the diameter b of the inner peripheral edge of the peripheral jet 15 are If the relationship between the diameter c of the central outlet 17 and the length Y in the axial direction of the converging outlet portion 14g of the peripheral outlet 14 is defined by the following equations [1] and [2], By making the inward angle α of the converging jet path portion 14g of the jet path 14 different, it is possible to form a strong flame and suppress the generation of NOx while changing the length of the flame. Was found.
[0023]
(Equation 1)
a ≧ 1.2b ≧ 3.6c
[0024]
(Equation 2)
Y ≧ (ab) / 2
[0025]
Further, assuming that the length of the cylindrical guide surface 16 in the axis P direction is X, the length X of the cylindrical guide surface 16 in the axial direction, the diameter a of the outer peripheral edge of the peripheral outlet 15, the peripheral outlet When the relationship between the diameters b of the inner peripheral edge of the nozzle 15 is defined by the following equation (3), the gaseous fuel ejected from the convergent ejection path portion 14g is supplied to the central ejection path by the cylindrical guide surface 16. It has been found that it is possible to guide the gas fuel flow ejected from the nozzle 13 to converge effectively toward the gas fuel flow.
[0026]
[Equation 3]
a>X> b
[0027]
As shown in FIGS. 5 and 6, the fuel supply portion Bs of the gas burner B has a cylindrical outer supply tube 18 and an inner supply tube 19 each having a distal end projecting beyond the distal end of the inner supply tube 19. And, the rear end of the inner supply tube 19 is assembled coaxially with the rear end of the outer supply tube 18 protruding from the rear end of the outer supply tube 18, and the rear end opening of the outer supply tube 18 is closed with an annular lid plate 20. A connection pipe 21 is connected to the device 18 so as to communicate therewith.
At the tip of the outer supply tube 18, a male screw portion 18 s that is screwed into the female screw portion 11 s of the outer tubular body 11 of the fuel ejection portion Bn is formed, and at the tip of the inner supply tube 19, the fuel ejection portion is formed. A male screw portion 19s is formed to fit with the female screw portion 12s of the inner cylindrical body 12 of Bn.
[0028]
Then, the rear end of the inner cylindrical body 12 of the fuel ejection section Bn is screwed into the tip of the inner supply cylinder 19 of the fuel supply section Bs, and the fuel ejection section is engaged with the tip of the outer supply cylinder 18 of the fuel supply section Bs. When the rear end of the outer cylindrical body 11 of the portion Bn is screwed, the fuel supply section Bs is provided with the fuel ejection section Bn in a state where the inner cylindrical body 12 and the outer cylindrical body 11 are arranged in the above-described positional relationship. It is configured so that can be attached.
[0029]
As shown in FIG. 3, a gas burner B having the fuel supply section Bs and the fuel ejection section Bn attached thereto as described above is inserted into the burner insertion hole 4b of the furnace wall 4 from the front end side of the fuel ejection section Bn and arranged. The gap between the periphery of the gas burner B and the burner insertion hole 4b is sealed with a sealing material 22 so as to block air from entering the furnace 3 from outside through the outer periphery of the gas burner B. is there.
[0030]
One of the two branch pipes 23b branched from the gas supply pipe 23 that supplies the gas fuel G such as city gas is connected to the rear end of the inner supply tube 19 of the fuel supply unit Bs, and the other branch pipe is connected. 23b is connected to the connection pipe 21 of the fuel supply section Bs.
Each branch pipe 23b is provided with a control valve 24 for adjusting the flow rate of gas fuel and a pressure gauge 25 for measuring the internal pressure.
The inner supply pipe 19 of the fuel supply section Bs also passes through the in-cylinder flow path in the central discharge path 13 of the fuel discharge section Bn, and the outer supply pipe 18 of the fuel supply section Bs connects to the peripheral discharge path 14 of the fuel discharge section Bn. The gas fuel G is individually supplied through the annular flow path between the inner supply cylinder 19 and each of them.
The two control valves 24 adjust the ratio between the amount of gas fuel ejected from the central ejection passage 13 and the amount of gas fuel ejected from the peripheral ejection passage 14 based on the pressure detected by each pressure gauge 25. The two control valves 24 constitute an ejection amount ratio adjusting means.
[0031]
By configuring the fuel ejection portion Bn as described above, the gas fuel G is ejected straight from the central ejection passage 13 along the axis P, and the central ejection passage 14 g of the peripheral ejection passage 14 is subjected to the central ejection. The gas fuel G is ejected so as to converge toward the gas fuel flow G ejected straight from the passage 13, and the gas fuel G ejected from the central ejection passage 13 and the convergent ejection passage portion 14g is formed into a cylindrical shape. Since the guide surface 16 is guided so as to flow forward while its spread is restricted, the gas fuel G is spouted vigorously from the fuel jetting portion Bn while the spread is suppressed as a whole, A strong flame F is formed.
Further, the gas fuel G is caused to flow through the peripheral ejection path 14 around the outer periphery of the fuel ejection portion Bn, and the fuel ejection portion Bn is cooled by the flow of the gas fuel G. Can be provided in a state where the infiltration of air into the furnace 3 is blocked by the sealing material 22, and the heating efficiency can be improved.
[0032]
The length of the flame F is adjusted by adjusting the ratio between the amount of gas fuel G ejected from the central ejection path 13 and the amount of gas fuel G ejected from the peripheral ejection path 14 by the two control valves 24. be able to. Incidentally, the ratio is set in a range where the generation amount of NOx does not become too large, and is usually adjusted to be 1: 1.
When the length of the flame F is changed beyond the range adjustable by the two control valves 24, the fuel ejection portion Bn attached to the fuel supply portion Bs is moved inward from the convergent ejection passage portion 14g. The fuel injection part Bn having a different angle α will be replaced. Incidentally, the flame F having a shorter length is formed at the fuel ejection portion Bn having a larger inward angle α.
[0033]
[Another embodiment]
Next, another embodiment will be described.
(B) In the above embodiment, the case where the present invention is applied to an end-port type glass melting furnace is described. However, for example, the present invention may be applied to a so-called side-port type glass melting furnace. it can.
As shown in FIG. 7, the side port type glass melting furnace is provided with an inlet 4i in a furnace wall 4 on one side of a rectangular melting tank 2 in a plan view, and the furnace wall 4 provided with the inlet 4i. A work tank 9 is provided outside the furnace wall 4 facing the furnace, and an opening 4 e (not shown) for communicating the melting tank 2 and the work tank 9 is provided in the furnace wall 4 between the work tank 9 and the melting tank 2. ) Is formed at the hearth of the melting tank 2.
The combustion device is provided with a pair of combustion parts respectively provided on the furnace wall 4 located on the left and right from the input port 4i toward the extraction hole 4e.
Each of the pair of combustion units is provided with two gas burners B for injecting the gas fuel G into the furnace 3 and one air port 5 (not shown) located above the gas fuel ejection point of the gas burner B. A plurality (four in FIG. 7) of gas burner sets including one air supply path 6 (not shown) for supplying combustion air A obliquely downward to the combustion area of the gas fuel G ejected from B. In addition to being provided side by side in the lateral direction, it is provided with one heat storage chamber 8 that communicates with a plurality of air supply passages 6 included in the plurality of gas burner sets.
Then, the pair of combustion sections are alternately burned at regular intervals to perform alternating combustion, and the glass material is charged into the melting tank 2 through the charging port 4i, and the glass material is melted while taking out the glass hole 4e. , And the clean molten glass is guided to the work tank 9 through the extraction hole 4e.
[0034]
(B) The number of gas burners B installed corresponding to each air port 5 is not limited to two as exemplified in the above embodiment, but may be one or three or more.
[0035]
(C) As the oxygen-containing gas for combustion supplied from the air port 5 to the inside of the furnace 3, in addition to the air exemplified in the above embodiment, a mixture of air and a combustion exhaust gas discharged from the inside of the furnace 3 or an oxygen-containing gas may be used. Various materials such as oxygen-enriched air with a high rate can be used.
[0036]
(D) The present invention can be applied to various combustion devices for heating furnaces other than the glass melting furnace exemplified in the above embodiment and the glass melting furnace exemplified in another embodiment shown in FIG. it can.
For example, in addition to the type in which the gas burner B is alternately burned, the present invention can be applied to a continuous combustion type.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional side view of a glass melting furnace provided with a combustion device for a heating furnace according to an embodiment.
FIG. 2 is a view taken in the direction of an arrow II in FIG. 1;
FIG. 3 is a longitudinal sectional side view of a main part of a glass melting furnace provided with a heating device for a heating furnace according to an embodiment.
FIG. 4 is a cross-sectional view of a gas burner of the combustion device for a heating furnace according to the embodiment, taken along a plane perpendicular to the axis of a fuel ejection portion.
FIG. 5 is a cross-sectional view of a gas burner of the combustion device for a heating furnace according to the embodiment, taken along a plane along an axis of a fuel ejection portion.
FIG. 6 is a cross-sectional view of the gas burner of the combustion device for a heating furnace according to the embodiment, taken along a plane along the axis of a fuel ejection portion.
FIG. 7 is a cross-sectional view of a glass melting furnace provided with a combustion device for a heating furnace according to another embodiment.
FIG. 8 is a longitudinal sectional view of a conventional combustion device for a heating furnace.
[Explanation of symbols]
3 inside the furnace
6 Oxygen-containing gas supply section
11 outer cylindrical body
12 Inner cylindrical body
13 Central spout
14 Surrounding jet
14g convergent jet path
15 Surrounding spout
16 Guideway
24 Volume control means
Bn fuel injection section
Bs fuel supply unit

Claims (4)

A fuel ejection section for ejecting gas fuel into the furnace,
An oxygen-containing gas supply unit for supplying a combustion oxygen-containing gas to a combustion zone of gas fuel ejected from the fuel ejection unit from a combustion oxygen-containing gas supply point different from the gas fuel ejection point of the fuel ejection unit. A combustion device for a provided heating furnace,
The fuel ejection portion is provided with an outer cylindrical body and an inner cylindrical body in a coaxial shape with a tip of the outer tubular body protruding from a tip of the inner tubular body, and a cylinder of the inner tubular body. Is configured to form a central ejection path within and form an annular peripheral ejection path between the inner cylindrical body and the outer cylindrical body,
The outer peripheral surface of the inner cylindrical body and the inner peripheral surface of the outer cylindrical body, each of which forms the tip side of the peripheral ejection path are formed in a tapered shape having a smaller diameter toward the tip side, and The leading end side is configured as a convergent ejection path portion that ejects gas fuel so as to converge from the outer peripheral side of the inner cylindrical body toward the axis center,
The inner peripheral surface of the protruding portion of the outer cylindrical body from the inner cylindrical body has the same diameter or substantially the same diameter as the outer peripheral edge from the outer peripheral edge of the annular peripheral jet at the tip of the convergent jet path portion. A combustion device for a heating furnace, which extends forward and has a cylindrical guide surface for guiding gas fuel ejected from the central ejection passage and the peripheral ejection passage. The length of the said cylindrical guide surface is shorter than the diameter of the outer peripheral edge of the said peripheral jet, and it is comprised so that it may be longer than the diameter of the inner peripheral edge of the said peripheral jet. Combustion device for heating furnace. The fuel ejection unit is configured to be replaceable with respect to a fuel supply unit that supplies gas fuel to the fuel ejection unit,
3. The combustion device for a heating furnace according to claim 1, wherein a plurality of fuel ejection portions having different angles directed toward the axis in the ejection direction of the convergent ejection path portion are provided as the fuel ejection portions. 4. An ejection amount ratio adjusting means for adjusting a ratio between an ejection amount of gas fuel from the central ejection passage and an ejection amount of gas fuel from the peripheral ejection passage is provided. A combustion device for the heating furnace according to the above.

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