JP3926205B2 - Plasma melting furnace restart method and plasma melting furnace equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is incineration ash and fly ash discharged from the garbage incinerator, etc. by heating and melting by plasma arc soil, volume reduction, restart method and a plasma melting furnace in a plasma melting furnace to reduce the detoxification Regarding equipment .
[0002]
[Prior art]
In the conventional twin torch type plasma ash melting furnace equipment, the base metal is accommodated in the bottom of the furnace body, the inside of the furnace body is made a reducing atmosphere, and the power supply device is connected to the positive and negative electrodes suspended from the ceiling. A plasma operating voltage is applied to form a plasma arc between the positive electrode and the base metal and between the negative electrode and the base metal. Then, the base metal is melted by the heat of the plasma arc, and ash is added to the molten base metal to heat and melt it. The generated molten slag is overflowed and discharged to the slag cooling device, and then water-cooled to remove the granulated slag. Generate.
[0003]
By the way, when the melting furnace is temporarily stopped and restarted from a cooled state, since the solidified slag having low conductivity is fixed on the slag base metal, the restart is performed by the following two methods, for example. The first is a slag removal method, in which an operator enters the furnace, removes the solidified slag below the positive electrode and the negative electrode, and polishes the surface of the base metal so that it can be energized. Then, after the positive electrode is lowered and grounded to the base metal, a plasma arc is generated only between the base metal and the negative electrode to gradually melt the solidified slag and the base metal around the base metal, thereby enhancing the conductivity. When the molten layer of metal reaches the vicinity of the positive electrode, the positive electrode is raised to generate a plasma arc between the base metal.
[0004]
The second is a carbon addition method, in which conductive carbon powder is added to the surface of the solidified slag between the positive electrode and the negative electrode, and the positive electrode is lowered and grounded to the carbon powder. A plasma arc is generated between the powder and restarted in the same procedure as described above.
[0005]
[Problems to be solved by the invention]
However, in the above slag removal method, the work of removing the solidified slag in the furnace becomes a heavy labor in a bad environment. Also, since the melting state of the base metal layer is indefinite from the generation of the plasma arc by the negative electrode to the twin plasma by both electrodes, the plasma arc is unstable, and the arc breaks when the load (supply power) is increased. There is a problem that it is necessary to melt over time with a small load.
[0006]
In addition, the carbon addition method has a problem that the plasma arc is unstable until the carbon powder floats on the surface of the molten slag and the added carbon is completely removed because the density of the added carbon is smaller than the molten slag. .
[0007]
An object of the present invention is to solve the above problems and provide a plasma melting furnace restarting method and plasma melting furnace equipment that can perform restarting smoothly and quickly.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the invention according to claim 1 is characterized in that a base metal housed in the bottom of the furnace body, a supply port for supplying a material to be melted onto the base metal, and a base from the ceiling of the furnace body. A plurality of electrodes arranged to be close to and away from the metal, a power supply device for applying a voltage of different polarity to the electrodes to generate a plasma arc between the base metal, and a plasma arc on the base metal. A method of restarting a plasma melting furnace having a slag discharge port for discharging a slag in which a melt is heated and melted, wherein the burner insertion port is opened by an opening / closing device, and the starter burner is waited outside the burner insertion port Insert into the furnace body from the position through the burner insertion port, stop at the use position close to the furnace bottom, ignite the starting burner and direct the flame toward the base metal below the electrodes And the slag on the base metal is melted to increase conductivity, and then the base metal is further melted, and when this molten layer reaches under the electrodes, the start burner is stopped and the use position is stopped. retracted to the standby position from the one in which closing the burner interpolation inlet by opening and closing device.
[0009]
According to the second aspect of the present invention, a base metal housed in the bottom of the furnace body, a supply port for supplying a material to be melted on the base metal, and the base metal from the ceiling of the furnace body are approached and separated from the base metal. A movable electrode freely disposed and a fixed electrode connected to the base metal, and a power supply device that generates a plasma arc between the movable metal and the base metal by applying a voltage of different polarity to the movable electrode and the fixed metal; A method for restarting a plasma melting furnace comprising a slag discharge port for discharging a slag in which a material to be melted is heated and melted by a plasma arc on a base metal, wherein the burner insertion port is opened by a switchgear and the starter burner is opened Is inserted into the furnace body from the standby position outside the burner insertion port through the burner insertion port, stopped at the use position close to the furnace bottom, and the start burner is ignited and flame After radiating toward the base metal between the movable electrode and the fixed electrode, melting the slag on the base metal to increase the conductivity, further melting the base metal, and this molten layer is between the movable electrode and the fixed electrode. In this case, the activation burner is stopped and retracted from the use position to the standby position, and the burner insertion port is closed by the opening / closing device.
[0010]
Furthermore, the invention described in claim 3 is a plasma melting furnace facility for carrying out the restarting method of the plasma melting furnace according to claim 1, wherein the switchgear is provided on the ceiling or side wall of the furnace body. A burner insertion opening, an activation burner capable of emitting a flame of 1600 to 1800 ° C., and a burner exit / retreat device capable of moving the activation burner between a standby position and a use position.
[0011]
Furthermore, the invention described in claim 4 is a plasma melting furnace facility for carrying out the restarting method of the plasma melting furnace according to claim 2, wherein the opening and closing provided on the ceiling or side wall of the furnace body. A burner insertion opening with a device, a starting burner capable of emitting a flame of 1600 to 1800 ° C., and a burner exit / retreat device capable of moving the starting burner between a standby position and a use position. .
[0012]
According to each of the above configurations, the activation burner can heat and melt the low-conductivity solidified slag between the lower part of the plurality of electrodes or between the movable electrode and the fixed electrode . Plasma can be ignited smoothly between the electrode and the base metal, and a stable plasma arc can be obtained. Therefore, the restart can be performed stably in a short time. Further, the starter burner can be retracted outside the furnace by the burner exit / retreat device, and the starter burner is not burned out.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Here, a first embodiment of the plasma ash melting furnace facility according to the present invention will be described with reference to FIG. 1 and FIG.
[0014]
This ash melting furnace heats and melts incineration ash and fly ash (melted material) discharged from an incinerator that incinerates municipal waste and industrial waste to reduce the volume and make it harmless. Thus, while the ash supply port (supply port) 2 which supplies ash to the one end side of the furnace main body 1 is formed, the slag discharge port 3 which discharges the molten slag S to the other end side, and the gas discharge port 4 Is formed.
[0015]
The ash supply port 2 is provided with an ash supply hopper 5, and an ash supply device 6 comprising a pusher 6 a and a pusher cylinder 6 b for supplying ash A into the furnace body 1 at a fixed amount at the bottom of the ash supply hopper 5. Is provided. Below the slag discharge port 3, a slag cooling device (not shown) for cooling the molten slag to produce water granulated slag is disposed, and the gas discharge port 4 discharges gas through the exhaust gas treatment device. An exhaust gas discharge line (not shown) is provided.
[0016]
A base metal M, which is a conductor, is accommodated at the bottom of the furnace main body 1. A carbon positive electrode 7 is provided on the ceiling 1a above the base metal M on the ash supply port 2 side, and a slag discharge port. The negative electrode 8 made of carbon is penetrating and penetrating on the 3 side so as to freely move up and down. A power supply device 11 is connected to each of the electrodes 7 and 8, and a plasma arc is formed between the power supply device 11 and the base metal M by applying a plasma driving voltage to each of the electrodes 7 and 8. Has been. Further, gas supply holes 7a and 8a are formed in the electrodes 7 and 8 from the upper end to the lower end along the axial center, respectively, and plasma working gas for starting plasma is supplied from the working gas supply device 12. Here, for the plasma working gas, for example, an inert gas such as nitrogen gas is used in order to reduce the consumption of the carbon electrodes 7 and 8 as much as possible. A gas supply nozzle (not shown) for blowing an inert gas such as nitrogen gas is provided in order to keep the inside of the furnace body 2 in a plasma operating state.
[0017]
In the ceiling 1a of the furnace body 1, a starting oxygen burner (melting the base metal (metal material, iron plate, etc.) M at the time of initial starting or melting the slag S fixed to the surface of the base metal M at the time of restarting ( A starter burner 21 is disposed between the electrodes 7 and 8, the starter oxygen burner 21 is supported by the burner retracting device 22, and the starter oxygen burner 21 is formed on the ceiling portion 1a. The burner insertion port 24 is provided so that it can be moved into and out of the furnace body 1.
[0018]
The starting oxygen burner 21 is a fuel that can emit a flame of 1600 to 1800 ° C. using oxygen as a fuel for combustion such as hydrogen, propane, butane, and LNG.
[0019]
As shown in FIG. 2, the burner exit / retreat device 22 is retracted via a support beam 32 attached to the support column 31 along the insertion direction, and a guide roller 33 disposed at a predetermined interval from the support beam 32. A retractable rod 34, which is supported freely and has an activation oxygen burner 21 attached to the tip, and sprockets 35a, 35b provided at the upper and lower ends of the support beam 32, are wound by a retractable motor 36. The chain 36 is driven via a sprocket 35 b, and a connecting member 34 a provided on the retracting rod 34 is connected to the chain 36. Therefore, by operating the retracting motor 37 to move the chain 36, the retracting rod 34 on the support beam 32 is retracted along the axial direction, and the starting oxygen burner 21 is removed from the burner insertion port 24 into the furnace. It is possible to move between the use position shown in FIG. 2A approaching the furnace bottom in the main body 1 and the standby position shown in FIG. 2B outside the burner insertion port 24.
[0020]
The opening / closing device 23 for the burner insertion port 24 is provided with an opening / closing cylinder 23b for rotating and opening the burner insertion port 24 while rotating the lid 23a.
[0021]
Next, a method for restarting the ash melting furnace after initial startup will be described.
The slag S is solidified and fixed on the base metal M solidified by the previous melting operation. First, the burner insertion port 24 is opened by the opening / closing device 23, and the starting oxygen burner 21 is inserted into the furnace main body 1 by the burner retracting device 22, and stopped at the use position approaching the slag S on the base metal M. Then, the starting oxygen burner 21 is ignited to emit a flame of 1600 to 1800 ° C., the solidified slag S is first melted, and then the base metal M is melted. When the molten layer reaches below the electrodes 7 and 8, the starting oxygen burner 21 is stopped. Further, the starter oxygen burner 21 is retracted from the use position to the standby position by the burner exit / retreat device 22, the burner insertion port 24 is closed by the opening / closing device 23, and an inert gas is supplied into the furnace body 1 to generate an inert gas atmosphere. To do.
[0022]
Next, the electrodes 7 and 8 are brought close to or in contact with the base metal M by an electrode lifting device (not shown), and a plasma working gas is supplied from the working gas supply device 12 and activated from the power supply device 11 to the electrodes 7 and 8. A working voltage is applied, and a plasma arc is ignited between the electrodes 7 and 8 and the base metal M. When the entire base metal M is melted by this plasma arc, ash is supplied and melting is resumed.
[0023]
Of course, the starting oxygen burner 21 can be used to melt the base metal material (iron plate or the like) at the time of initial starting.
According to the above-described embodiment, it is not necessary to remove the solidified slag in the furnace main body 1 which is hard labor under a poor environment as in the prior art, and the plasma arc is stably formed to form the slag S and the base metal. Since M can be melted, it can be restarted in a short time.
[0024]
FIG. 3 shows a second embodiment of an ash melting furnace of a single torch (a plurality of possible) ash melting furnace. The bottom of the furnace body 1 of the ash melting furnace is suspended from a fixed electrode (positive electrode) 41 connected to the base metal M and connected to the anode of the power supply device 11 and the ceiling part 1a of the furnace body 1 so as to be freely raised and lowered. And a movable electrode (negative electrode) 42 to which the cathode of the power supply device 11 is connected. The starting oxygen burner 21 is configured to be withdrawn and retracted in an oblique direction by the burner retracting device 22 to melt the base metal M and the solidified slag S below the movable electrode 42. Others are configured in the same manner, and the same operational effects can be achieved.
[0025]
FIG. 4 shows that in the ash melting furnace of the first and second embodiments, the starting oxygen burner 21 is discharged into the furnace body 1 through the burner insertion port 24 formed in the side wall 1b of the furnace body 1. Removable.
[0026]
A burner insertion port 24 with an opening / closing device 23 is formed on one of both side walls corresponding to the base metal M between the electrodes 7 and 8 and the solidified slag S, and is activated by the burner retracting device 22 having substantially the same structure. The oxygen burner 21 is driven into and out of a use position where the oxygen burner 21 approaches the base metal M and the solidified slag S in the furnace body 1 from the burner insertion port 24 and a standby position retracted outside the furnace body 1.
[0027]
Other structures and methods of use are the same as in the above embodiment, and the same operational effects can be achieved.
In the above embodiment, the material to be melted is ash, but it may be a melting furnace for melting industrial waste or the like. Also, although the electrodes 7, 8, and 42 are shown one by one, a plurality of electrodes are shown. May be.
[0028]
【The invention's effect】
As described above, according to the present invention, the activation burner can melt the solidified slag having low conductivity between the lower portions of the plurality of electrodes or between the movable electrode and the fixed electrode to increase the conductivity. Therefore, plasma can be ignited smoothly between the electrode and the base metal, and a stable plasma arc can be obtained. Therefore, the restart can be performed stably in a short time. Further, the starter burner can be retracted outside the furnace by the burner exit / retreat device, and the starter burner is not burned out.
[Brief description of the drawings]
1 is a configuration diagram showing a first embodiment of the plasma ash melting furnace equipment according to the present invention.
FIG. 2 shows the burner exit / retreat device, wherein (a) is a side view showing a use state, and (b) is a side view showing a standby state.
FIG. 3 is a configuration diagram showing a second embodiment of the plasma ash melting furnace facility according to the present invention.
FIG. 4 is a configuration diagram showing a third embodiment of the plasma ash melting furnace equipment according to the present invention.
[Explanation of symbols]
M base metal S slag 1 furnace body 2 ash supply port 3 slag discharge port 5 ash supply hopper 6 ash supply device 7 positive electrode 8 negative electrode 11 power supply device 12 working gas supply device 21 starting oxygen burner 22 burner retracting device 23 opening / closing Device 24 Burner insertion port 31 Support column 32 Support beam 33 Guide roller 34 Retracting rod 37 Retracting motor 41 Fixed electrode 42 Movable electrode

Claims (4)

A base metal housed in the bottom of the furnace body, a supply port for supplying a material to be melted onto the base metal, and a plurality of electrodes disposed so as to be close to and away from the base metal from the ceiling of the furnace body; A power supply device for applying a voltage of different polarity to the electrode to generate a plasma arc between the base metal and a slag discharge port for discharging a slag in which a material to be melted is heated and melted by the plasma arc on the base metal; A plasma melting furnace restarting method comprising :
Open the burner insertion port with the opening and closing device, insert the activation burner from the standby position outside the burner insertion port into the furnace body through the burner insertion port, and stop at the use position close to the furnace bottom,
After igniting the starting burner and radiating a flame toward the base metal below the electrodes, melting the slag on the base metal to improve conductivity, further melting the base metal,
When the molten layer spans between the lower of the plurality of electrodes, are retracted to the standby position from the use position to stop the start burner, re plasma melting furnace, characterized in that closing the burner insertion port by the opening and closing device starting method. A base metal housed in the bottom of the furnace body, a supply port for supplying a material to be melted onto the base metal, a movable electrode disposed so as to be close to and away from the base metal from the ceiling of the furnace body, and the above A fixed electrode that is electrically connected to the base metal, a power supply device that generates a plasma arc between the base metal by applying voltages of different polarities to the movable electrode and the fixed electrode, and a target metal that is melted by the plasma arc A method for restarting a plasma melting furnace comprising a slag discharge port for discharging slag in which an object is heated and melted ,
Open the burner insertion port with the opening and closing device, insert the activation burner from the standby position outside the burner insertion port into the furnace body through the burner insertion port, and stop at the use position close to the furnace bottom,
After igniting the starting burner and radiating a flame toward the base metal between the movable electrode and the fixed electrode, melting the slag on the base metal to increase the conductivity, then further melting the base metal,
Then, when this molten layer reaches between the movable electrode and the fixed electrode, the starting burner is stopped and retracted from the use position to the standby position, and the burner insertion port is closed by the opening and closing device . How to restart. A plasma melting furnace facility for carrying out the restarting method of the plasma melting furnace according to claim 1,
A burner insertion opening with a switchgear provided on the ceiling or side wall of the furnace body;
A starting burner capable of emitting a flame of 1600 to 1800 ° C .;
A burner exit / exit device capable of withdrawing the start burner between the standby position and the use position.
This is a plasma melting furnace facility. A plasma melting furnace facility for carrying out the restarting method of the plasma melting furnace according to claim 2,
A burner insertion opening with a switchgear provided on the ceiling or side wall of the furnace body;
A starting burner capable of emitting a flame of 1600 to 1800 ° C .;
A burner exit / exit device capable of withdrawing the start burner between the standby position and the use position.
This is a plasma melting furnace facility.

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