JP4548785B2 - Waste gasification melting apparatus melting furnace, and control method and apparatus in the melting furnace - Google Patents

Description

  The present invention relates to a technology for gasifying and melting waste, and in particular, a melting furnace for a waste gasification and melting apparatus that can reliably ignite and melt even low-calorie waste, and control in the melting furnace. The present invention relates to a method and an apparatus.

  Conventionally, a gasification and melting apparatus is known as an apparatus that can treat a wide range of wastes such as municipal waste, non-combustible waste, incineration residue, sludge, and landfill waste. The gasification and melting apparatus is provided with a gasification furnace for thermally decomposing waste to gasify and a pyrolysis gas generated in the gasification furnace at a downstream side of the gasification furnace, It has a melting furnace that melts ash content into slag and a secondary combustion chamber that combusts exhaust gas discharged from the melting furnace. In order to reduce the waste resources, reduce the volume and make them harmless, The slag is taken out from the furnace and reused as a civil engineering material such as a roadbed material, or the waste heat is recovered from the exhaust gas discharged from the secondary combustion chamber to generate electric power (Patent Document 1, etc.).

In such a gasification and melting apparatus, a pyrolysis gas containing ash generated in the gasification furnace is introduced into the melting furnace, and the ash in the gas is melted in the melting furnace heated to high temperature by the energy of the pyrolysis gas. Sluged. However, in the vicinity of the pyrolysis gas supply port of the melting furnace, clinker may adhere in the transition temperature range during the temperature rise process, and if the clinker grows, the pyrolysis gas supply port and the combustion chamber in the furnace may be blocked. is there.
Therefore, in Patent Document 2 (Japanese Patent Application Laid-Open No. 2003-4214), the inner wall surface of the primary combustion chamber of the melting furnace is in the vicinity of the generated gas (pyrolysis gas) inlet provided on the upper side wall of the melting furnace. Provided with a plurality of combustion gas supply nozzles whose front end portions are open, and a plurality of combustion gas supply nozzles whose front end portions are open on the ceiling wall of the melting furnace. That is, a gasification melting furnace for supplying oxygen-enriched air or oxygen is disclosed. As a result, mixing of the product gas and the combustion gas is promoted, the temperature can be raised quickly, and adhesion of the clinker to the wall surface can be prevented.

As described above, in the melting furnace, it is required to surely convert the ash generated in the gasification furnace into a molten slag in the furnace. For this reason, the inside of the melting furnace is 1200 to 1500 which is a melting point of ash. Need to be maintained at ℃.
Taking a powdery waste melting furnace as an example, in order to achieve stable high-temperature combustion, in Patent Document 3 (Patent No. 2505561), melting having a configuration as shown in FIGS. 15 (a) and 15 (b) A furnace is proposed. FIG.15 (b) is the II-II sectional view taken on the line of (a). This melting furnace includes a furnace body 71 having a cylindrical shape with a substantially vertical axis and a conical upper portion, and a sludge burner 72 provided at the lower portion of the furnace body 71 and having a nozzle facing the cutting line direction of the furnace body. And a slag outlet 74 provided at the lower end of the furnace main body 71, and a gas outlet 75 connected to the upper end of the furnace main body 71 and extending upward with a smaller diameter than the furnace main body. The cone angle θ is more than 45 ° and less than 75 °, and the ratio of the inner diameter d of the gas outlet 75 to the inner diameter D of the furnace body is more than 0.2 and less than 0.6. Further, as shown in a cross-sectional plan view shown in FIG. 15B, the melting furnace is provided with a sludge heavy oil mixed burner 73 on a furnace inner wall surface different from the sludge burner 72. Sludge and heavy oil for assisting combustion are blown into the furnace body from the sludge heavy oil mixed burner 73 to maintain the furnace temperature.

JP 2004-144402 A JP 2003-4214 A Japanese Patent No. 2505561

As with the powdery waste melting furnace of Patent Document 3, auxiliary fuel is often used in the gasification melting apparatus in order to maintain the inside of the furnace at a high temperature. However, while the sludge to be treated in Patent Document 3 has about 5000 kcal / kg of calories, the pyrolysis gas generated in the gasifier is extremely ^high, about 800 to 1000 kcal / m ^3. There is a problem that the amount of auxiliary fuel used is low. In addition, the pyrolysis gas is low in calories, so the ignitability is poor, and if auxiliary fuel is used to improve the ignitability, there is a problem that the amount of fuel used further increases and the environmental load and running cost increase. .
Further, in Patent Document 2, since the combustion gas supply nozzle is provided at a position different from the generated gas supply port, mixing of the generated gas and the combustion gas may be insufficient, and the combustion is smoothly performed. There is a risk that the temperature inside the furnace will be lowered. Patent Document 2 mainly aims to prevent clinker adhering to the vicinity of the product gas supply port. Therefore, the problem of ignitability cannot be solved when processing low-calorie waste as described above.

  Therefore, in view of the above-mentioned problems of the prior art, the present invention improves the ignitability of a gasification and melting apparatus for treating waste, ignites quickly even with a low-calorie pyrolysis gas, and An object of the present invention is to provide a melting furnace of a waste gasification melting apparatus capable of performing a smooth melting process while maintaining a high temperature, and a control method and apparatus in the melting furnace.

In order the present invention is to solve the above problems, the pyrolysis gas generated by the gasification of waste, as well as to be introduced into the furnace from the pyrolysis gas burner provided in the furnace wall, the thermal decomposition in the melting furnace of the auxiliary fuel burner and is provided waste gasification melting apparatus adapted to jet an auxiliary fuel and combustion air consisting of gaseous fuel or liquid fuel to facilitate the ignition of the gas in the appropriate furnace,
The pyrolysis gas burner is arranged so as to eject pyrolysis gas toward the tangential direction of a virtual circle formed by the pyrolysis gas swirl flow in the furnace, and always emits a flame to the pyrolysis gas burner. The seed fire burner is disposed at a horizontal position or above the horizontal position of the pyrolysis gas burner so that a flame is jetted toward the center of the outlet of the pyrolysis burner, and the jet direction of the seed fire burner And the axis of the pyrolysis gas burner are arranged so as to be 90 ° or less. At this time, the angle is preferably less than 80 °.

  According to the present invention, it is possible to promote ignition even with a low-calorie pyrolysis gas by providing the pyrolysis gas burner with the above-described seed fire burner and constantly igniting the seed fire burner. is there. Further, when an auxiliary fuel burner is provided separately, the amount of auxiliary fuel used can be greatly reduced, and the running cost of the entire apparatus can be greatly reduced.

In addition, the seed fire burner is arranged at a horizontal position on the peripheral surface of the pyrolysis gas burner or above the horizontal position.
Thereby, it is possible to prevent solid matter such as char accompanying the pyrolysis gas from falling and blocking the nozzle hole of the seed fire burner.

The melting furnace according to claim 1 or 2 , wherein a pyrolysis gas generated by gasification of waste is introduced into the furnace from a pyrolysis gas burner provided on the furnace wall. In
The pyrolysis gas burner is provided with combustion air supply holes for supplying combustion air into the pyrolysis gas burner.
Note that air, oxygen, oxygen-enriched air, or the like is used as the combustion air.
According to the present invention, since the pyrolysis gas and the combustion air are premixed in the burner by blowing the combustion air into the pyrolysis gas burner, the pyrolysis gas mixed with the combustion air is instantaneously mixed in the melting furnace. Can be burned. Therefore, combustion in the melting furnace can be promoted and complete combustion can be realized in a shorter time.
A plurality of the combustion air supply holes are provided on the peripheral surface of the pyrolysis gas burner, and a combustion air header communicating with the combustion air supply holes is provided.
Thereby, since combustion air disperse | distributes and is supplied in a pyrolysis burner, combustion air and pyrolysis gas are mixed more effectively, and combustion is accelerated | stimulated.

Further, a plurality of the combustion air supply holes are provided on the same circumference of the pyrolysis gas burner peripheral surface, and a plurality of stages of the combustion air supply holes on the same circumference differ in the axial direction of the pyrolysis gas burner. Provided, the supply holes of adjacent combustion air supply hole arrays are alternately arranged. Thereby, the mixability of pyrolysis gas and combustion air improves further.
Furthermore, a plurality of the combustion air supply holes are provided on the same circumference of the pyrolysis gas burner peripheral surface, and a plurality of the combustion air supply hole arrays on the same circumference are varied in the axial direction of the pyrolysis gas burner. In addition to being provided with a stage, each combustion air supply hole row is provided with an independent combustion air header. Thus, by setting it as the structure which has each independent combustion air header, it becomes possible to adjust easily the air quantity supplied from each supply hole according to the required quantity of combustion air.

Further, the pyrolysis gas burner is arranged so as to eject pyrolysis gas toward a tangential direction of a virtual circle formed by a pyrolysis gas swirl flow in the furnace.
Thereby, a swirl | vortex flow can be formed smoothly and combustion is accelerated | stimulated.

In addition, the seed flame burner that constantly injects a flame to the furnace wall of the melting furnace, and auxiliary fuel and combustion air made of gaseous fuel or liquid fuel that promote ignition of the pyrolysis gas are appropriately injected into the furnace. an auxiliary fuel burner you are provided,
The auxiliary fuel burner is arranged to eject auxiliary fuel in a tangential direction of a virtual circle formed by a pyrolysis gas swirl flow in the furnace.
As in the present invention, by providing an auxiliary fuel burner having the same swirling flow diameter as the swirling flow diameter formed by the gas ejected from the pyrolysis gas burner, ignition of low-calorie pyrolysis gas is achieved. Can be promoted.

The auxiliary fuel burner is disposed in the vicinity of the pyrolysis gas burner, and is disposed upstream of the pyrolysis gas burner with respect to the swirling direction of the pyrolysis gas swirl flow.
Furthermore, it is preferable that an angle formed between the jet direction of the auxiliary fuel burner and the axis of the pyrolysis gas burner is more than 20 ° and not more than 90 °.
Thus, by providing the auxiliary fuel burner on the upstream side of the swirl flow of the pyrolysis gas burner and in the vicinity of the pyrolysis gas burner, even if the pyrolysis gas has a lower calorie, it is thermally decomposed by the flame of the auxiliary fuel burner. Gas ignition can be promoted and burned quickly. Moreover, according to this invention, it can prevent that the ejection hole of an auxiliary | assistant fuel burner wears out by the jet of the pyrolysis gas from a pyrolysis gas burner.

Furthermore, in the case where a plurality of the pyrolysis gas burners and the auxiliary fuel burners are provided, the plurality of pyrolysis gas burners are arranged at substantially equal intervals, and the plurality of auxiliary fuel burners are arranged at substantially equal intervals, The pyrolysis burners or the auxiliary fuel burners are arranged so as not to be adjacent to each other.
Thereby, it is possible to prevent the ejection holes of the auxiliary fuel burner from being worn out by the jet of pyrolysis gas from the pyrolysis gas burner. Moreover, by setting it as this structure, it becomes easy to form the swirl | vortex flow in a furnace.

Moreover, in the control method in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
A flame is always ejected by a seed flame burner provided in the pyrolysis gas burner, and an auxiliary fuel and combustion air are appropriately ejected into the furnace by an auxiliary fuel burner provided on the furnace wall,
Wherein detecting the temperature of the melting furnace, on the basis of the detected temperature, the flow rate control of the fuel and combustion air supplied to the species flame burners, and characterized by performing the ignition control of the auxiliary fuel burner.
Note that air, oxygen, oxygen-enriched air, or the like is used as the combustion air.

  Furthermore, at this time, when the temperature in the melting furnace exceeds the upper limit value of the temperature appropriate range set in advance, the first step of reducing the flow rate of the fuel and combustion air supplied to the seed fire burner, When the temperature in the melting furnace is less than the lower limit value of the appropriate temperature range, the second step of increasing the flow rate of the fuel and combustion air supplied to the seed burner increased in the second step. And a third step of igniting the auxiliary fuel burner when the flow rate exceeds a preset maximum value of the appropriate range of the flow rate of the seed fire burner.

  Thus, the melting furnace temperature is controlled by controlling the flow rate of the fuel and combustion air supplied to the seed burner and / or the flow rate of the auxiliary fuel and combustion air supplied to the auxiliary fuel burner based on the temperature in the melting furnace. It can be kept appropriate, and the amount of fuel supplied to the melting furnace can be reduced, and the running cost can be reduced.

Moreover, in the control method in the melting furnace of the waste gasification melting apparatus according to claim 10 or 11 ,
A flame is always ejected by a seed flame burner provided in the pyrolysis gas burner, and an auxiliary fuel and combustion air are appropriately ejected into the furnace by an auxiliary fuel burner provided on the furnace wall,
Detecting a temperature of the melting furnace, based on the temperature, the species fire bars Naa Rui is characterized in that control the temperature of the combustion air supplied to the auxiliary fuel burner.

  In this way, by controlling the temperature of the combustion air supplied to the seed burner and / or the temperature of the combustion air supplied to the auxiliary fuel burner based on the temperature in the melting furnace, the melting furnace temperature can be kept appropriate. The amount of fuel supplied to the melting furnace can be reduced, and the running cost can be reduced.

Moreover, in the control apparatus in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
The pyrolysis gas burner is provided with a seed flame burner that constantly injects flames, and an auxiliary fuel burner that appropriately ejects auxiliary fuel made of gaseous fuel or liquid fuel that promotes ignition of pyrolysis gas into the furnace. A melting furnace provided,
A temperature sensor for detecting a temperature in the melting furnace, a seed fire burner control means for controlling a flow rate of fuel and combustion air supplied to the seed fire burner based on the detected temperature, and the detection And auxiliary fuel burner control means for controlling the flow rate of auxiliary fuel and combustion air supplied to the auxiliary fuel burner based on the measured temperature and the flow rate of the seed burner.

Moreover, in the control apparatus in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
The pyrolysis gas burner is provided with a seed flame burner that constantly injects flames, and an auxiliary fuel burner that appropriately ejects auxiliary fuel made of gaseous fuel or liquid fuel that promotes ignition of pyrolysis gas into the furnace. A melting furnace provided,
A temperature sensor for detecting a temperature in the melting furnace, a seed fire burner control means for controlling a flow rate of fuel and combustion air supplied to the seed fire burner based on the detected temperature, and the detection And auxiliary fuel burner control means for controlling the flow rate of auxiliary fuel and combustion air supplied to the auxiliary fuel burner based on the measured temperature and the flow rate of the seed burner.

  As described above, according to the present invention, it is possible to promote the ignition and combustion of the pyrolysis gas in the melting furnace even when low-calorie waste is to be treated, and to consume auxiliary fuel. Since the amount can be greatly reduced, the running cost can be greatly reduced.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
FIG. 1 is an overall configuration diagram of a system including a gasification and melting apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic diagram illustrating a cross section taken along line AA (FIG. 1) of the melting furnace according to the first embodiment. 3 is a diagram for explaining the definition of the swirl number, FIGS. 4 to 6 are diagrams showing the structure of a seed furnace burner of the melting furnace according to the first embodiment, and FIGS. 7 to 11 are heats of the melting furnace according to the present embodiment. FIG. 12 is a diagram showing the configuration of the cracked gas burner, FIG. 12 is an overall configuration diagram of a system including a gasification and melting apparatus according to the second embodiment, and FIGS. 13 and 14 are control flow diagrams of the gasification and melting apparatus.

[System overall configuration]
With reference to FIG. 1, an example of a processing flow of a system including a gasification and melting apparatus according to the first embodiment will be described.
First, the garbage collected from each collection point is accumulated in a garbage pit (not shown), and the garbage in the garbage pit is thrown into the garbage hopper 10 by a crane, and is crushed to 200 mm or less by a coarse crusher if necessary. After that, it is put into the dust feeder 11. The crushed waste is quantitatively supplied to the fluidized bed gasifier 12 by the dust feeder 11.
In the gasification furnace 12, combustion air 33 having a temperature of about 120 to 230 ° C. and an air ratio of about 0.2 to 0.7 is blown from the lower part of the furnace, and the in-furnace sand layer temperature is maintained at about 550 to 650 ° C. Garbage is gasified. Here, air ratio = combustion air amount / theoretical air amount necessary for complete combustion of garbage.

The crushed waste is gasified in the gasification furnace 12 and decomposed into gas, tar and char (carbide). Tar is a component that becomes liquid at room temperature, but is present in a gaseous state in the gasification furnace.
Char is gradually pulverized in the sand layer and is introduced into the melting furnace 13 along with gas and tar. Hereinafter, these components introduced into the melting furnace 13 are collectively referred to as a pyrolysis gas 34.
The bottom of the gasification furnace 12 is inclined about 12.5 ° downward from the crushed garbage inlet to the incombustible discharge outlet, and incombustibles such as bottles, cans and rubble in the garbage are incombustible together with fluid sand. It is smoothly extracted from the object discharge port. The extracted incombustible material and fluidized sand are screened with a vibrating sieve or the like, and then fluidized sand is returned to the gasification furnace. Of the incombustible materials that have been sieved, iron and aluminum are recovered as valuable materials, and other incombustible materials (mainly glass and rubble) are crushed and returned to the waste pit. The pulverized incombustible material is introduced into the melting furnace 13 from the gasification furnace 12 along with the pyrolysis gas 34 and is recovered as slag.

The pyrolysis gas 34 discharged from the top of the gasification furnace 12 is introduced into the pyrolysis gas burner 61 (see FIG. 2) of the melting furnace 13 through a lining duct. In the pyrolysis gas burner 61, the pyrolysis gas 34 is mixed with combustion air 57 and introduced into the furnace to form a swirling flow. At this time, the combustion air 57 may have an air ratio of 0.9 to 1.1, preferably about 1.0.
In the melting furnace 13, the mixed gas of the pyrolysis gas 34 and the combustion air 57 is burned, so that the furnace temperature is maintained at 1300 to 1500 ° C., and the ash in the pyrolysis gas is melted and slagged. The molten slag adheres and flows down on the inner wall surface of the melting furnace 13 and is discharged from the slag outlet at the bottom of the furnace. The slag discharged from the melting furnace 13 is rapidly cooled in the slag granulated water tank 23, carried out by the slag conveyor 24, and collected as granulated slag. The recovered granulated slag can be effectively used for roadbed materials and the like.
The inner wall of the melting furnace 13 has a water cooling structure in which a water cooling pipe is embedded, and a slag self-coating layer cooled and solidified by water cooling is formed on the inner wall surface of the furnace, thereby preventing the refractory material from being eroded. ing.

On the other hand, the combustion exhaust gas discharged from the melting furnace 13 is introduced into the secondary combustion chamber 14 via a conical spreading portion. In the secondary combustion chamber 14, the combustion air 35 is supplied so as to have an air ratio of 1.2 to 1.5, and the unburned component in the combustion exhaust gas is completely burned here.
The combustion exhaust gas is heat recovered by the boiler 15 and cooled to about 250 ° C. The combustion exhaust gas discharged from the boiler 15 is introduced into the temperature reducing tower 16 and is cooled to about 150 ° C. by direct water spray. The combustion exhaust gas discharged from the temperature reducing tower 16 is sprayed with slaked lime and activated carbon in the flue as necessary, and introduced into the reaction dust collector 17.
The reaction dust collector 17 removes soot, acid gas, DXNs and the like in the combustion exhaust gas. Fly ash discharged from the reaction dust collector 17 is landfilled by drug treatment, flue gas is reheated by the steam heater 18, NO _x is removed by catalytic reactor.

The above is the processing flow of the system including the gasification melting apparatus according to the present embodiment, and a specific embodiment of the melting furnace applied to this system is as follows.
[Configuration of pyrolysis gas burner]
As shown in FIG. 2, the melting furnace 13 according to the present embodiment has a substantially cylindrical furnace wall 60, and one or a plurality of pyrolysis gas burners 61 are attached to the furnace wall 60 in a horizontal cross section. ing. The pyrolysis gas burner 61 is arranged so that the pyrolysis gas 34 introduced from the burner is ejected in a tangential direction of a circle 65 (hereinafter referred to as an imaginary circle) rotating in the furnace.

尚、ＳＷ：スワール数[−]、ｄ：仮想円径[ｍ]、Ｄ：溶融炉内径[ｍ]、ｍ：ガス質量流量[kg/s]、ｒ：仮想円半径[m]、Ｒ：溶融炉半径[m]、Ｖ：空塔速度[m/s]であり、Ｂはバーナ吹出方向、ｚは溶融炉鉛直軸方向である。
スワール数が上記した範囲内となるように熱分解ガスバーナ径を設定することにより、バーナ吹出口にスラグが付着し、閉塞する不具合を防止できる。 The diameter of the pyrolysis gas burner 61 is preferably set so that the swirl number is 3 to 10 and the burner blowing flow rate is 30 m / s. At this time, the swirl number is defined by the following equation.

SW: number of swirls [-], d: virtual circle diameter [m], D: melting furnace inner diameter [m], m: gas mass flow rate [kg / s], r: virtual circle radius [m], R: Melting furnace radius [m], V: superficial velocity [m / s], B is burner blowing direction, z is melting furnace vertical axis direction.
By setting the pyrolysis gas burner diameter so that the swirl number is within the above-described range, it is possible to prevent a problem that slag adheres to the burner outlet and becomes blocked.

[Composition of seed fire burner]
As shown in FIG. 2, the pyrolysis gas burner 61 is provided with a seed flame burner 62 that ejects a flame toward the center of the outlet of the burner 61. The seed fire burner 62 ejects a fuel such as a liquid fuel such as kerosene or a gas fuel such as propane, thereby igniting the pyrolysis gas 34.
The construction of the seed fire burner 62 is shown in FIGS.
The seed flame burner 62 shown in FIG. 4 is disposed on the peripheral surface of the pyrolysis gas burner 61. The seed fire burner 62 is attached so that the fuel blowing direction substantially coincides with the center of the outlet of the pyrolysis gas burner 61, and an angle formed by the axis of the seed fire burner 62 and the axis of the pyrolysis gas burner 61. It is attached so that θ is 90 ° C. or less, preferably less than 80 ° (see FIG. 4B).
More preferably, as shown in FIG. 4C, the mounting position of the seed flame burner 62 is positioned horizontally or above the peripheral surface of the pyrolysis gas burner 61. That is, the vertical attachment position of the seed fire burner is set such that the angle θ with respect to the pyrolysis gas burner 61 is 0 ≦ θ ≦ 180 °. As a result, it is possible to prevent solid matter such as char accompanying the pyrolysis gas from dropping and blocking the nozzle hole of the seed fire burner 62.

The seed fire burner 62 shown in FIG. 5 is inserted from the peripheral surface of the pyrolysis gas burner 61 and is bent inside the pyrolysis gas burner 61 so as to be substantially parallel to the axis of the pyrolysis gas burner 61. ing. The fuel blowing direction of the seed flame burner 62 is made to substantially coincide with the center of the outlet of the pyrolysis gas burner 61 as in FIG.
In this configuration, the jet flow from the seed flame burner 62 does not hinder the jet flow of the pyrolysis gas, and the flow of the pyrolysis gas can be made smooth.
FIG. 6 shows a configuration in which a seed flame burner 62 is arranged from the downstream side of the pyrolysis gas burner 61 toward the outlet of the burner. Even in this configuration, the flow of the pyrolysis gas can be made smooth as in FIG.

[Configuration of auxiliary fuel burner]
Here, in the melting furnace 13 according to the present embodiment, the configuration when the auxiliary fuel burner 63 is installed will be described with reference to FIG.
One or more auxiliary fuel burners 63 are provided on the furnace wall 60 of the melting furnace 13. The auxiliary fuel burner 63 is arranged to have a swirl flow diameter substantially the same as the swirl flow diameter of the gas ejected from the pyrolysis gas burner 61. That is, the auxiliary fuel burner 63 is arranged so that the auxiliary fuel blowing direction Y of the auxiliary fuel burner 63 is tangent to the virtual circle 65 formed by the pyrolysis gas.
Further, when the auxiliary fuel burner 63 is provided at the same height with respect to the furnace wall, it is preferably provided in the vicinity of the pyrolysis gas burner 61 and on the upstream side of the swirl flow.
More preferably, in the auxiliary fuel burner 63, the angle of the auxiliary fuel blowing direction Y of the auxiliary fuel burner 63 with respect to the combustion gas blowing direction X of the pyrolysis gas burner 61 is more than 20 ° and not more than 90 ° (20 ° < (θ ≦ 90 °) is preferable.
As described above, by providing the auxiliary fuel burner 63 on the upstream side of the swirl flow of the pyrolysis gas burner 61 and in the vicinity of the pyrolysis gas burner 61, even if the pyrolysis gas has a lower calorie, The ignition of the pyrolysis gas can be promoted by the flame and can be burned quickly. Further, according to this configuration, it is possible to prevent the ejection holes of the auxiliary fuel burner 63 from being worn by the pyrolysis gas jet from the pyrolysis gas burner 61.

Another embodiment in which two auxiliary fuel burners 63 are arranged will be described. As shown in FIG. 2, when quadrants are assigned to four regions that pass through the furnace center and are divided by the x axis and the y axis that are orthogonal to each other, and the upper right side of the drawing is the first quadrant, the second is counterclockwise. The quadrant, the third quadrant, and the fourth quadrant. The auxiliary fuel burners 63 are provided so as to be located in different quadrants, and are respectively installed in quadrants that are not adjacent to each other. For example, when one auxiliary fuel burner 63 is provided in the second quadrant as shown, another auxiliary fuel burner 53 is provided in the fourth quadrant.
Thereby, it is possible to prevent the ejection holes of the auxiliary fuel burner 63 from being worn by the jet of pyrolysis gas from the pyrolysis gas burner 61. Further, the arrangement as in this configuration is preferable because a swirl flow in the furnace is easily formed.
The auxiliary fuel burner 64 is supplied with liquid fuel such as kerosene or gaseous fuel such as propane, and is used to maintain the temperature at the time of start-up and fall when the temperature in the melting furnace is lowered. The

[Premixing of combustion air]
Next, an example of premixing of the pyrolysis gas burner 61 will be described.
The pyrolysis gas burner 61 of this embodiment is provided with a plurality of nozzle holes on the circumferential surface of the burner body, and combustion air is blown into the burner from the nozzle holes. As the combustion air, air, oxygen, oxygen-enriched air, or the like can be used. At this time, the combustion air may have an air ratio of 0.9 to 1.1, preferably about 1.0. By setting the air ratio in this way, the furnace temperature can be stably maintained at a high temperature.
In this way, the pyrolysis gas and the combustion air are mixed in advance in the burner and then blown into the melting furnace 13, so that the pyrolysis gas and the combustion air are sufficiently mixed, and the pyrolysis gas is put into the furnace. Can be burned instantly.

Specific examples of the pyrolysis gas burner 61 having a premixing mechanism are shown in FIGS.
The pyrolysis gas burner 61 shown in FIG. 7 is provided with an annular combustion air header 611 on the outer peripheral surface, and the combustion air header 611 and the pyrolysis gas burner 61 have a plurality of combustion air dispersion holes (combustion air supply holes) 612. It is communicated by. The combustion air dispersion holes 612 are provided on the peripheral surface of the pyrolysis gas burner 61, and a plurality of the combustion air dispersion holes 612 are arranged at predetermined intervals along the same circumferential direction of the burner 61. In this embodiment, the plurality of dispersion holes 612 are arranged in a single stage. The combustion air header 611 is always at a positive pressure so that pyrolysis gas does not flow into the header.
Thus, by providing the plurality of combustion air dispersion holes 612, the pyrolysis gas and the combustion air are effectively mixed. Further, by providing the combustion air header 611, the combustion air can be sent uniformly to each combustion air dispersion hole 612.

In FIG. 8, like the pyrolysis gas burner 61 shown in FIG. 7, an annular combustion air header 611 and a plurality of combustion air dispersion holes 612 are provided on the outer peripheral surface. In this embodiment, two stages of combustion air dispersion hole arrays in which the combustion air dispersion holes 612 are arranged on the same circumference are provided at different positions in the axial direction of the pyrolysis gas burner 61. Further, as shown in FIGS. 8C-1 and 8C-2, the positions of the combustion air dispersion holes 612 are alternately arranged so as to be shifted from each other.
Thus, by arranging a plurality of stages of combustion air dispersion hole arrays, the mixing effect of the pyrolysis gas and the combustion air can be further improved.

FIG. 9 shows a configuration in which the combustion air header 611 and the combustion air dispersion holes 612 are provided in the same manner as the pyrolysis gas burner 61 shown in FIGS. 7 and 8, but in this embodiment, it is provided in a plurality of stages. Independent combustion air headers 611a and 611b are provided in the combustion air dispersion holes 612a and 612b, respectively.
Thus, by setting it as the structure which has each independent combustion air header 611a, 611b, according to the introduction amount of combustion air, the air quantity supplied to header 611a, 611b can be adjusted, respectively. For example, when the amount of combustion air introduced is large, the headers 611a and 611b are supplied with substantially the same amount of combustion air, and when the amount of combustion air introduced is small, either the header 611a or the header 611b is supplied. Reduce the amount of combustion air supply.

In FIG. 10, a combustion air header 611 is provided slightly spaced from the outer peripheral surface of the pyrolysis gas burner 61. The header 611 has an annular structure with a circular cross section. A plurality of combustion air dispersion holes are provided on the same circumference on the peripheral surface of the pyrolysis gas burner 61, and the dispersion holes and the combustion air header 611 are connected to each other by a combustion air introduction pipe 613.
Thus, by providing the combustion air header 611 having an annular structure with a circular cross section, the pressure loss of the combustion air is reduced and smooth supply of combustion air is possible.

In FIG. 11, as in FIG. 10, the combustion air header 611 having an annular structure with a circular cross section is provided, but a plurality of stages of combustion air dispersion holes are provided in the same manner as in FIG. 9. Combustion air headers 611a and 611b independent of the dispersion holes, and combustion air introduction pipes 613a and 613b connecting them are provided. Thereby, flow control of combustion air becomes easy.
In FIG. 11C, the combustion air introduction pipe 613 is provided at an angle with respect to the pyrolysis gas burner 61. The introduction pipe 613 is attached so that the combustion air ejected into the pyrolysis gas burner 61 turns. Thereby, it becomes easier to mix combustion air and pyrolysis gas. This configuration can also be applied to the pyrolysis gas burner 61 of FIG.

FIG. 12 shows an overall configuration diagram of a system of a gasification and melting apparatus provided with various control means according to the second embodiment, and FIGS. 13 and 14 show a control flow of the system. In the second embodiment, detailed description of the same configuration as that of the first embodiment shown in FIG. 1 is omitted.
As shown in FIG. 12, the control mechanism of the gasification furnace 12 includes furnace temperature control devices 50 and 52 for controlling the temperature in the gasification furnace, and the temperature of the combustion air supplied to the gasification furnace 12. An air temperature control device 51 for controlling the air temperature is provided.
The furnace temperature control device 52 controls the supply amount of the combustion air 33 supplied from the lower part of the furnace based on the furnace temperature detected by the temperature sensor 39 installed in the gasification furnace. The supply amount of the combustion air 33 is adjusted by controlling the opening degree of the damper 47. The combustion air 33 is guided to the lower part of the furnace by the blower 32, and is heated to a predetermined temperature via the heat exchanger 31 in the path, and then supplied to the furnace. The temperature of the combustion air is raised by heat exchange with the steam 36 in the heat exchanger 31. At this time, the temperature of the combustion air 33 on the downstream side of the heat exchanger 31 is detected by the temperature sensor 37, and the air temperature control device. Based on the temperature detected by 51, the amount of steam supplied to the heat exchanger 31 is controlled by the damper 38 to adjust the temperature. In addition, the steam 36 introduced into the heat exchanger 31 uses steam generated in the boiler 15 at the rear stage of the secondary combustion chamber 14.
When the amount of generated heat of the dust is low and the supply amount of the combustion air 33 exceeds the maximum value, the furnace temperature control device 50 controls the dust feeder motor 30 to be fed from the dust feeder 11 to the gasifier 12. Reduce the supply of crushed waste.
When the amount of heat generated by the dust is high and the supply amount of the combustion air 33 becomes less than the minimum value, the damper 38 is controlled by the air temperature control device 51, the flow rate of the steam 36 is decreased, and the temperature of the combustion air 33 is lowered.

On the other hand, as a control mechanism of the melting furnace 13, an in-furnace temperature control device 54 for controlling the temperature in the melting furnace, an air temperature control device 53 for controlling the temperature of the combustion air 57 supplied to the melting furnace 13, An O ₂ concentration control device 55 for controlling the supply amount of combustion air 57 and 37 supplied to the melting furnace 13 and the secondary combustion chamber 14 is provided.
The in-furnace temperature control device 54 controls the temperature in the furnace by controlling the supply amount of the auxiliary fuel 58 by the valve 41 based on the in-furnace temperature detected by the temperature sensor 40 installed in the melting furnace. .

Further, since the furnace temperature also depends on the temperature and oxygen concentration of the combustion air 57, these are controlled by the air temperature control device 53 and the O ₂ concentration control device 55, respectively.
The air temperature control device 53 adjusts the temperature of the combustion air 57 based on a control command from the furnace temperature control device 54. This controls the supply amount of the steam 36 to the heat exchanger 31 that raises the temperature of the combustion air 57 by adjusting the opening degree of the damper 43 to set the temperature of the combustion air 57. At this time, the temperature of the combustion air 57 on the downstream side of the heat exchanger 31 may be detected by the temperature sensor 42 and feedback control based on the temperature may be added.

Further, in the O ₂ concentration control device 55, the exhaust gas component at the rear stage of the reaction dust collector 17 is detected by the sensor 44, the flow rates of the combustion air 57 and the combustion air 37 are detected, and suitable combustion is performed in the melting furnace. As described above, the opening amounts of the dampers 46 and 49 are controlled to adjust the supply amounts of the combustion air 57 and 37 in the furnace.
By these controls, the combustion state in the melting furnace 13 and the secondary combustion chamber 14 is suitably maintained, and generation of harmful substances such as NOx and DXNs is prevented.

Next, FIG. 13 and FIG. 14 show a combustion control method of the melting furnace 13 by the seed flame burner 62 and the auxiliary fuel burner 63 shown in the first embodiment.
As shown in FIG. 13, first, the temperature in the furnace is measured by the temperature sensor 40 installed in the melting furnace, and the melting furnace temperature is compared with the upper limit value H of the appropriate temperature range of the melting furnace (S1). When the melting furnace temperature is higher than the upper limit value H, the flow rate of the seed flame burner 62 is reduced (S2). It is determined whether or not the burner flow rate is the minimum value (S3). If it is not the minimum value, the process returns to the beginning of this flow and the same processing is performed.
On the other hand, when the melting furnace temperature is lower than the upper limit value H, the melting furnace temperature is further compared with the lower limit value L of the appropriate temperature range (S4), and when the temperature is lower than the lower limit value L, the seed burner 62 The flow rate is increased (S5), and it is determined whether or not the current burner flow rate exceeds the maximum value of the appropriate flow rate range (S6). If the burner flow rate exceeds the maximum value, the auxiliary fuel burner 63 is ignited (S7), and the melting furnace temperature and the lower limit L are compared again (S8). If the melting furnace temperature is still lower than the lower limit value L even when the auxiliary fuel burner 63 is used, the auxiliary fuel burner flow rate is further increased (S9), and the melting furnace temperature is returned to the comparison with the lower limit value L (S8).

  On the other hand, in the comparison between the melting furnace temperature and the upper limit value H (S8), when the melting furnace temperature is higher than the lower limit value L, it is compared with the upper limit value H (S10). If the temperature is increased too much, the flow rate of the seed burner 62 is reduced (S11). Then, it is determined whether or not the burner flow rate is the minimum value (S12). If it is the minimum value, the auxiliary burner 63 is extinguished (S13). When it is not the minimum value and when it is lower than the upper limit value H in the comparison between the melting furnace temperature and the upper limit value H (S10), the melting furnace temperature is returned to the comparison with the lower limit value L (S8). After extinguishing the auxiliary burner 63 (S13), the process returns to the beginning of this flow.

  The flow shown in FIG. 14 is applied when it is determined whether or not the burner flow rate is the minimum value in FIG. 13 (S3). In this case, the melting furnace temperature is compared with the upper limit value H (S14). If the melting furnace temperature is lower than the upper limit value H, the process returns to the beginning. The air temperature of the next blower is lowered to lower the temperature of the combustion air 57 (S15). Then, this time, the melting furnace temperature is compared with the lower limit value L (S16), and when it is higher than the lower limit value L, the process returns to the beginning, and when it is lower than the lower limit value L, that is, when the furnace temperature is not appropriate The air temperature of the secondary blower is raised to raise the temperature of the combustion air 57 (S17). Further, it is determined whether or not the air temperature of the secondary blower is the upper limit. If it is the upper limit, the process returns to the beginning of the flow shown in FIG. If it is not the upper limit, the process returns to the beginning of this flow.

In this way, by controlling the flow rate of the seed flame burner 62 and the flow rate of the auxiliary fuel burner 63 based on the temperature in the melting furnace 13, the melting furnace temperature can be properly maintained and the fuel to the melting furnace 13 can be maintained. The supply amount can be reduced, and the running cost can be reduced.
In the present embodiment, the seed fire burner 62 is always ignited, and by forming a small flame with much less fuel than the auxiliary fuel burner 63, the amount of fuel used in the auxiliary fuel burner 63 is greatly increased. As a result, the running cost of the entire apparatus can be greatly reduced.

1 is an overall configuration diagram of a system including a gasification melting apparatus according to an embodiment of the present invention. It is the schematic which shows the AA sectional view (FIG. 1) of the melting furnace which concerns on the present Example 1. FIG. It is a figure explaining the definition of the number of swirls applied to a present Example. 1 shows the configuration of the seed furnace burner of the melting furnace according to the first embodiment, (a) is a cross-sectional view taken along the line AA in FIG. 1, (b) is a diagram showing the mounting angle of the seed fire burner, (c) is ( It is BB sectional drawing of b). It is a figure which shows the structure of the seed fire burner provided with the structure different from FIG. It is a figure which shows the structure of the seed-day burner provided with the structure different from FIG. 4, FIG. The structure of the pyrolysis gas burner of the melting furnace which concerns on a present Example is shown, (a) is a perspective view, (b) is a side view, (c) is CC sectional view taken on the line of (b). The structure of the pyrolysis gas burner provided with the structure different from FIG. 7 is shown, (a) is a perspective view, (b) is a side view, (c-1) is the DD sectional view taken on the line of (b), c-2) is a cross-sectional view taken along line EE of (b). The structure of the pyrolysis gas burner provided with the structure different from FIG. 7, FIG. 8 is shown, (a) is a perspective view, (b) is a side view, (c-1) is the FF sectional view of (b). FIG. 4C-2 is a cross-sectional view taken along line GG in FIG. The structure of the pyrolysis gas burner provided with the structure different from FIGS. 7-9 is shown, (a) is a perspective view, (b) is the HH sectional view taken on the line of (a). The structure of the pyrolysis gas burner provided with the structure different from FIGS. 7-10 is shown, (a) is a perspective view, (b-1) is the II sectional view taken on the line of (a), (b-2) (A) is the JJ sectional view taken on the line, (c) is the II sectional view taken on the line which shows another example of (b-1). It is a whole block diagram of the system provided with the gasification melting apparatus which concerns on the present Example 2. It is a control flowchart (1) of the melting furnace which concerns on the present Example 2. It is a control flowchart (2) of the melting furnace which concerns on the present Example 2. The structure of the conventional powdery waste melting furnace is shown, (a) is a longitudinal cross-sectional view, (b) is the II-II sectional view taken on the line of (a).

Explanation of symbols

12 gasifier 13 melting furnace 14 secondary combustion chamber down 15 boiler 16 cooling tower 17 reaction precipitator 18 steam heater 34 pyrolysis gas 40 furnace temperature sensor 44 and 45 O ₂ concentration sensor 50 furnace temperature controller 51 Air temperature control device 52 In-furnace temperature control device 53 Air temperature control device 54 In-furnace temperature control device 55 O ₂ concentration control device 60 Furnace wall 61 Pyrolysis gas burner 62 Seed burner 63 Auxiliary fuel burner 65 Virtual circles 611, 611a 611b Combustion air header 612, 612a, 612b Combustion air dispersion hole (combustion air supply hole)
613, 613a, 613b Combustion air introduction pipe

Claims (14)

The pyrolysis gas generated by the gasification of the waste is introduced into the furnace from the pyrolysis gas burner provided on the furnace wall, and a seed fire burner that constantly injects a flame, and ignition of the pyrolysis gas in the melting furnace waste gasification melting apparatus and an auxiliary fuel burner so as to jet an appropriate furnace auxiliary fuel and combustion air consisting of a gaseous fuel or a liquid fuel is provided to facilitate,
The pyrolysis gas burner is arranged so as to eject pyrolysis gas toward the tangential direction of a virtual circle formed by the pyrolysis gas swirl flow in the furnace, and always emits a flame to the pyrolysis gas burner. The seed fire burner is disposed at a horizontal position or above the horizontal position of the pyrolysis gas burner circumferential surface so that a flame is ejected toward the center of the outlet of the pyrolysis gas burner, and the jet direction of the seed fire burner And a melting furnace of a waste gasification and melting apparatus, wherein the angle between the axis of the pyrolysis gas burner and the axis of the pyrolysis gas burner is 90 ° or less. The seed flame burner for constantly injecting flames to the furnace wall of the melting furnace, auxiliary fuel composed of gaseous fuel or liquid fuel for promoting ignition of the pyrolysis gas, and combustion air are appropriately injected into the furnace. and an auxiliary fuel burner is provided,
The waste gasification according to claim 1, wherein the auxiliary fuel burner is arranged so as to eject the auxiliary fuel toward a tangential direction of an imaginary circle formed by a pyrolysis gas swirl flow in the furnace. Melting furnace for melting equipment. The melting furnace according to claim 1 or 2 , wherein the pyrolysis gas generated by gasification of waste is introduced into the furnace from a pyrolysis gas burner provided on the furnace wall.
A melting furnace of a waste gasification melting apparatus, wherein the pyrolysis gas burner is provided with a combustion air supply hole for supplying combustion air into the pyrolysis gas burner.   4. The waste gasification and melting apparatus according to claim 3, wherein a plurality of the combustion air supply holes are provided on a peripheral surface of the pyrolysis gas burner, and a combustion air header communicating with the combustion air supply holes is provided. Melting furnace.   A plurality of the combustion air supply holes are provided on the same circumference of the pyrolysis gas burner circumferential surface, and a plurality of stages of combustion air supply holes on the same circumference are provided at different positions in the axial direction of the pyrolysis gas burner. The melting furnace of the waste gasification melting apparatus according to claim 3 or 4, wherein supply holes of adjacent combustion air supply hole arrays are alternately arranged.   A plurality of combustion air supply holes are provided on the same circumference of the pyrolysis gas burner peripheral surface, and a plurality of combustion air supply hole arrays on the same circumference are provided in different stages in the axial direction of the pyrolysis gas burner. The melting furnace of the waste gasification melting apparatus according to claim 3 or 4, wherein an independent combustion air header is provided for each combustion air supply hole row. The auxiliary fuel burner, while being disposed near the pyrolysis gas burner, according to claim 1 or characterized in that it is arranged on the upstream side of the pyrolysis gas burner with respect to the turning direction of the pyrolysis gas swirling flow The melting furnace of the waste gasification melting apparatus according to 2 . The melting furnace of the waste gasification melting apparatus according to claim 2 or 7 , wherein an angle formed between the jet direction of the auxiliary fuel burner and the axis of the pyrolysis gas burner is more than 20 ° and not more than 90 °. . A plurality of the pyrolysis gas burners and the auxiliary fuel burners are provided , the plurality of pyrolysis gas burners are arranged at substantially equal intervals, and the plurality of auxiliary fuel burners are arranged at substantially equal intervals, and the pyrolysis burners or the The melting furnace of a waste gasification melting apparatus according to claim 7, wherein the auxiliary fuel burners are arranged so as not to be adjacent to each other. In the control method in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
A flame is always ejected by a seed flame burner provided in the pyrolysis gas burner, and an auxiliary fuel and combustion air are appropriately ejected into the furnace by an auxiliary fuel burner provided on the furnace wall,
Detecting a temperature of the melting furnace, on the basis of the detected temperature, the seed flow control fire fuel and combustion air supplied to the burner, and waste gas and performing ignition control of the auxiliary fuel burner Control method in a melting furnace of a chemical melting apparatus. A first step of reducing the flow rate of fuel and combustion air supplied to the seed burner when the temperature in the melting furnace exceeds an upper limit value of a preset temperature appropriate range; When the temperature is less than the lower limit value of the appropriate temperature range, the second step of increasing the flow rate of the fuel and combustion air supplied to the seed fire burner and the flow rate increased in the second step are when exceeding the maximum value of the flow proper range of the set pilot flame burners, waste gasification of claim 1 0, wherein further comprising a third step of igniting the auxiliary fuel burner Control method in melting furnace of melting apparatus. In the control method in the melting furnace of the waste gasification melting apparatus according to claim 10 or 11 ,
A flame is always ejected by a seed flame burner provided in the pyrolysis gas burner, and an auxiliary fuel and combustion air are appropriately ejected into the furnace by an auxiliary fuel burner provided on the furnace wall,
The temperature in the melting furnace is detected, and the temperature of the combustion air supplied to the seed flame burner or the auxiliary fuel burner is controlled based on the temperature, and the control in the melting furnace of the waste gasification melting apparatus Method. In the control apparatus in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
The pyrolysis gas burner is provided with a seed flame burner that constantly injects flames, and an auxiliary fuel burner that appropriately ejects auxiliary fuel made of gaseous fuel or liquid fuel that promotes ignition of pyrolysis gas into the furnace. A melting furnace provided,
A temperature sensor for detecting a temperature in the melting furnace, a seed fire burner control means for controlling a flow rate of fuel and combustion air supplied to the seed fire burner based on the detected temperature, and the detection Waste gasification and melting, comprising: auxiliary fuel burner control means for controlling the flow rate of auxiliary fuel and combustion air supplied to the auxiliary fuel burner based on the measured temperature and the flow rate of the seed burner Control device in the melting furnace of the device. In the control apparatus in the melting furnace of the waste gasification melting apparatus according to claim 1 or 2 ,
The pyrolysis gas burner is provided with a seed flame burner that constantly injects flames, and an auxiliary fuel burner that appropriately ejects auxiliary fuel made of gaseous fuel or liquid fuel that promotes ignition of pyrolysis gas into the furnace. A melting furnace provided,
The melting furnace includes a temperature sensor for detecting a temperature in the melting furnace, and means for controlling a temperature of combustion air supplied to the seed burner or the auxiliary fuel burner based on the detected temperature. The control apparatus in the melting furnace of the waste gasification melting apparatus characterized.

Images