JP3408772B2 - Operation control method and apparatus for plasma melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to industrial waste, municipal solid waste such as household waste, and incineration residue in a refuse incinerator, main ash,
The present invention relates to a method and an apparatus for controlling the operation of a melting furnace that melts fly ash and other waste before incineration, and in particular estimates the increase in molten metal that accumulates in the furnace when waste is melted, The present invention relates to an operation control method and apparatus for a plasma melting furnace, which detects a tapping time to be taken out and performs tapping operation based on the detection signal.

[0002]

2. Description of the Related Art Municipal refuse, sewage sludge, industrial waste, and their incinerated ash, fly ash, and residues (hereinafter simply referred to as incineration residues) are often landfilled. However, in recent years, it has become increasingly difficult to secure landfill sites, so there is a demand for a method of reducing the volume of incinerated ash or the like to be landfilled. In addition, organic substances from landfilled incineration ash, harmful substances such as heavy metals, elute into rainwater and groundwater,
There is also concern about the problem of causing secondary pollution, and technologies for making these pollution-free are also required.

On the other hand, from the viewpoint of reusing resources, there is a demand for reusing materials that were conventionally landfilled as incinerated ash. Incinerated ash of municipal waste is sorted by magnetism and sieving, and metallic substances are reused as new resources.
There is also a demand for a method of reusing the remaining ash. In response to such a demand, a method has been realized in which incineration ash is put into a melting furnace such as a plasma furnace, a burner furnace, an induction furnace and the like is melted and processed. According to these methods, by melting the incinerated ash at a high temperature, the harmful components in the incinerated ash can be decomposed at a high temperature, and the metal component can be separated as molten metal (metal) from the molten slag.

Solidified molten slag has a large volume reduction rate from incinerated ash, and since it is in a vitrified state, harmful substances in the slag do not elute into rainwater or groundwater. I don't have to worry. Also, the slag is
It can also be reused by using concrete aggregate instead of gravel and pebbles, or by blocking it into road tiles. On the other hand, as a melting furnace in recent years, a melting treatment furnace that directly melts not only the melting of incinerated ash but also waste is considered, and these are also effective because the waste incineration process in the middle is unnecessary. This is a waste treatment method.

A conventional example of a plasma ash melting furnace which is one of melting furnaces for melting incineration residues and fly ash in a refuse incinerator will be described with reference to FIG. The melting furnace 1 has a DC power supply device 2 and uses a plasma electrode 5 inserted from the upper part of the furnace to generate a high temperature plasma by causing a discharge between the melting electrode 1 and a furnace bottom electrode 6. The incineration ash introduced into the furnace from the melted material supply port 7 provided in the upper part of the furnace is heated by the radiant heat of the plasma and the Joule heat generated by the electric current passing through the molten slag 9 and the molten metal (metal) 10 to be melted. To do.

The incinerator ash charged into the furnace through the charging port 7 has a high heat (1300) generated by Joule heat generated when a plasma arc and an electric current flow in the slag.
The molten slag 9 is melted at a temperature of up to 2000 ° C., but the incineration ash that is melt-processed in the plasma melting furnace contains a component such as silica that forms the molten slag 9 and a metal component such as iron that forms the molten metal 10. ing.

Therefore, the incinerated ash melted in the furnace is
Molten slag 9 with a low specific gravity floats to the top, and molten metal 1
Zero sinks to the bottom and separates into two layers. The molten slag 9 in the upper layer continuously flows out so as to overflow from the slag gutter 3 and is gradually cooled by the slag transport conveyor 8 and collected. There is also a method of collecting as water granulated slag by dropping it into a large cooling water tank and rapidly cooling it instead of gradually cooling it by the slag transport conveyor 8.

If such an operation is continued, the molten slag 9 in the upper layer is continuously discharged out of the furnace, but the molten metal 10 in the lower layer gradually accumulates. Since the amount of the metal component is smaller than that of the slag component, the accumulation rate is not fast, but the molten metal layer gradually thickens and the liquid level of the molten metal layer rises, so that the molten slag layer becomes thin on the contrary.

As described above, the Joule heat generated by the slag 9 as a resistance when an electric current flows through the molten slag layer is
It is one of the heat sources for melting. On the other hand, since the electric resistance value of the molten metal (metal) 10 whose deposited layer thickness increases due to the melting treatment is much smaller than that of the molten slag 9, its calorific value is also small, and the increase of the molten metal layer is the same current. When operating, this also leads to a decrease in heat generation and is not desirable for operating the furnace. Therefore, when the molten metal 10 is accumulated, an operation called tilting for tilting the furnace 1 to discharge the molten metal (metal) 10 is intermittently performed in order to discharge the molten metal 10 to the outside of the furnace.

[0010]

Therefore, in the conventional melting equipment, there is a need to detect the amount of the molten metal 10 accumulated in the furnace as the material to be melted is melted in order to determine the tilting operation timing. However, because there is a high temperature (1300 to 2000 ° C) and highly corrosive gas in the furnace, it is not possible to place a sensor that can measure stably for a long period of time. However, there was a problem that judgments varied due to individual differences and differences in experience.

[0011] Further, since various types of municipal waste and industrial waste are mixed, the physical properties of incineration ash, fly ash, etc., which are the incineration residues thereof, are naturally not stable and the physical properties fluctuate with time. In addition, when making such a thing as a melted object,
If the molten metal 10 is discharged at a predetermined time interval because the rate of increase in the deposition of the molten metal 10 changes, the tilting timing may be delayed and the tilting may not be ready in time, or the tilting frequency may be too fast. However, there was a problem that efficient operation could not be performed, such as a decrease in melting time due to an increase in temperature.

Further, in the method of disposing the level detecting electrode in the melting portion as disclosed in Japanese Patent Laid-Open No. 9-280536, the electrode is melted at a high temperature in the furnace, and the electrode is worn or broken due to convection of the melt. There is a problem such as adhesion of slag to the electrode surface, and since it is difficult to detect the damage state of these electrodes from the outside, there is concern about stable detection for a long time for tilt timing timing control. There was a problem like that.

According to the present invention, it is possible to accurately and accurately predict the deposition of molten metal in a waste melting furnace without installing a sensor in the furnace, and to determine the discharge timing of molten metal by an operator. With the aim of providing an operation control method and an apparatus for a waste melting furnace, which can be known without relying on the experience and intuition, especially an operation control method and an apparatus for a waste melting furnace of a waste plasma melting treatment furnace. To do.

[0014]

The invention according to claim 1 is
It corresponds to the first invention of the present invention, and the weighing for distinguishing slag and molten metal is performed immediately before melting in a waste melting treatment furnace that discharges molten metal accumulated under the molten slag by a predetermined means in each discharge cycle. When the amount of waste input into the furnace in the current cycle after metal discharge is measured, and the total amount of waste input in the current cycle exceeds a predetermined preset value, the molten metal discharge timing is When it is judged that it came , the default value is corrected for each discharge cycle
It is characterized by being.

According to the present invention, it is possible to accurately and surely predict that the molten metal has accumulated in the melting furnace without installing a sensor in the furnace, thereby discharging the molten metal from the furnace. You can know the time without depending on the experience and intuition of the operator. The present invention is a method for controlling the operation of the waste melting furnace and is not limited to the plasma waste melting furnace, but can be applied to other internal melting furnaces and electric arc furnaces. In addition, the term "waste" as used herein refers to waste, etc. that includes incineration residue in a refuse incinerator, main ash, and fly ash, and may be melt-processed in a melting furnace.

In order to improve the accuracy of the invention described in claim 1, the invention described in claim 2 measures the amount of molten metal at the time of discharging the molten metal in each cycle, and discards the measured value of at least the current cycle. It is characterized in that the specified value for determining the next molten metal discharge time is corrected by obtaining the molten metal amount per the material input amount.

According to this invention, even if the properties of the material to be melted are seasonally changed or change with time, it can be corrected from the amount of molten metal discharged, and an accurate discharge timing can be obtained. .

The invention according to claim 3 relates to an apparatus for effectively carrying out the invention according to claim 1, wherein the waste to be charged into the furnace in the current cycle after the immediately preceding discharge of the molten metal is discharged. Means for measuring the input amount, means for comparing the measured total amount of waste input in the present cycle with a predetermined value, and discharge control means for setting the discharge timing of the molten metal based on a signal from the comparing means Tomo and comprises a door
In addition, the predetermined value is corrected for each discharge cycle .

The invention according to claim 4 is an invention relating to an apparatus for effectively carrying out the invention according to claim 2, wherein means for measuring the molten metal amount at the time of discharging the molten metal in each cycle, and And a correction unit for correcting the specified value for determining the next molten metal discharge timing based on the detection signals from the two detection units. It is characterized by

A fifth aspect of the present invention corresponds to the second aspect of the present invention, in which the waste is melted by plasma discharge while a constant current is applied by a DC power supply having a constant current control function to melt the waste. In the furnace, the voltage fluctuations during operation between the plasma electrode and the bottom electrode are monitored, and the instantaneous negative voltage fluctuations are detected and counted, and the number of occurrences per unit time exceeds the specified number of times. It is characterized in that when the state continues for a predetermined time, it is judged that the molten metal discharge time has come.

According to the present invention, no special sensor for detecting the weight of molten metal slag is required, and it is possible to accurately determine that the molten metal has accumulated due to the voltage fluctuation of the DC voltage source applied to the plasma electrode. It is possible to reliably detect, and not only know the molten metal discharge timing without relying on the experience and intuition of the operator, but it is also possible to deal with temporary changes in the properties of the molten material, This makes it possible to detect optimal waste input control and abnormality determination.

The invention according to claim 6 relates to an apparatus for effectively carrying out the invention according to claim 5, which is a voltage fluctuation detecting means for detecting a voltage fluctuation during operation between the plasma electrode and the furnace bottom electrode. And a counting means for detecting and counting an instantaneous voltage fluctuation in the negative direction from the voltage fluctuation, and a state in which the number of occurrences of the instantaneous voltage fluctuation per unit time exceeds a predetermined prescribed number for a predetermined time. In this case, a determining means for determining that it is time to discharge the molten metal is provided.

The invention according to claim 7 is the first invention and the second invention.
A more accurate determination of the molten metal discharge timing is made by combining the gist of the invention, and the molten metal discharge timing is based on the total amount of waste input into the furnace in the current cycle after the immediately preceding molten metal discharge. And a second determining means for determining the discharge timing of the molten metal based on the instantaneous negative voltage fluctuation between the plasma electrode and the furnace bottom electrode.
And determining the discharge timing of the molten metal based on one or both of the determination signals.

According to this invention, the above two inventions can be combined to back up and complement each other, and it is possible to provide a more reliable discharge timing determination and operation control device.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, unless otherwise specified, the types, materials, shapes, relative arrangements, and operating procedures of the constituent parts described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely It is only an example.

FIG. 1 is an overall configuration diagram of an operation control device for a plasma ash melting furnace according to a first embodiment of the present invention. The present invention will be described based on the diagram. In the figure, the same reference numerals as those in FIG. 5 denote the same functional parts or parts, and detailed description of those parts will be omitted. In the figure, reference numeral 1 denotes a plasma ash melting furnace in which molten slag 9 and molten metal 10 are deposited in the furnace, and a slag gutter 3 is attached to the side of the furnace corresponding to the molten slag 9. Reference numeral 8 denotes a slag transporting conveyor, which gradually cools the molten slag 9 that is continuously flowing out so as to overflow from the slag gutter 3 while it is being transported. Air-cooled slag and molten metal 10
Is measured by the weight measuring device 22, and the weight measurement signal is sent to the molten metal amount calculating device to perform predetermined calculation and measurement.

The weighing for distinguishing the slag and the molten metal can be easily determined by the presence or absence of tilting of the furnace. That is, after the start of tilting of the furnace 1, the molten metal (metal) 10 is taken out from the conveyor exit by considering the feed speed and the conveyor length of the conveyor 8 from the timing at which the molten metal (metal) 10 comes out on the conveyor 8. Since the time to reach the end can be known and the measurement start timing of the molten metal 10 can be obtained, the measurement can be performed separately from the molten slag 9. Further, the amount of molten metal can be measured more accurately if a magnetic separation device for selecting with a magnet, a metal determination device with magnetism, a molten metal selector such as an image processing determination device is installed and accurately sorted. Thereby, the total amount of the molten metal (metal) 10 discharged during the tilting period can be smoothly obtained by the molten metal measuring device 38.

Reference numeral 25 is a furnace pushing-up mechanism, which is a tilt control device 3
The furnace 1 is tilted around the fulcrum 26 at a predetermined timing according to an instruction from the operation panel 37 based on the signal from the control unit 5. Two
Is a DC power supply device, which discharges plasma 17 in a furnace filled with nitrogen gas 18 between a main electrode (plasma electrode) 5 and a furnace bottom electrode 6 inserted from the upper part of the furnace (see FIG. 3).
Reference numeral 7 denotes an ash charging port provided on the upper part of the furnace, and an ash charging device 12 is provided on the ash charging port via a charging amount measuring device 21. The tilt control device 35 is controlled by the comparison signal obtained by comparing the signals from the tilt timing input amount storage device 32 and the input amount integrating device 33 with the comparator 34.

The tilting timing input amount storage device 32 is provided with a manual setting device 31 and an input amount correction device 39, and these signals are input to the storage device 32. In addition, 3 in the figure
Reference numeral 6 is a display panel, and 37 is an operation panel, which are connected to the tilt control device 35, respectively.

In such a device, the ash input measuring device 2
1 is installed in the ash feeding device 12 to measure the amount of ash charged into the furnace, and the charging amount integration device 33 measures the total charging amount for each batch (each tilting timing interval). The comparator 34 compares the set value of the tilting timing input amount storage device 32 for which the total tilting amount input has been set with the integrated value of the input amount integrating device 33. If the integrated value exceeds the set value, the comparator 34 The tilt control device 35 is notified that the tilt time has come. The tilt control device 35 displays on the display panel 36 that the tilting time has come, and the operator enters the tilting work by issuing a tilting operation instruction from the operation panel 37. The tilt control device 35 may automatically perform the tilting operation.

The setting of the input amount in the tilting timing input amount storage device 32 is manually performed by the operator using the manual setting device 31. The set value can be determined based on the experience value of an experienced operator, or the input amount can be calculated from the metal components contained by analyzing the input ash. In addition, the operator has a work plan,
So that the tilting operation can be started after considering the shift personnel, even if the tilting is displayed on the display board 36, there is a margin of several hours to one day before the tilting operation is started. It is necessary to set. This is because, for example, when a display indicating that the tilting time has been reached is displayed at night, it is possible to make a judgment such as performing tilting operation during daytime driving with a lot of shift personnel. However, when the tilting control device 35 performs the tilting operation fully automatically, the display is displayed on the display panel 36 for confirmation, but the tilting control device 35 performs the tilting operation.

The tilting work is to tilt the furnace 1 as shown in FIG. 2 and discharge the molten metal 10 accumulated in the furnace to the outside of the furnace. A hinge serving as a fulcrum 26 during operation is provided on one side of the bottom of the melting furnace, and a furnace pushing-up mechanism 2 including a hydraulic jack, an electric cylinder, etc. is provided on the other side.
5 are provided. Thus, by lifting one side of the furnace 1, the furnace 1 can be tilted about the fulcrum 26, the furnace 1 is gradually tilted, and the predetermined angle (2
Tilt from 0 to 40 °). After discharging the molten metal 10, the furnace 1 is returned to the original state. The tilt control device 35 sends a reset signal to the charging amount accumulating device 33 to initialize the accumulator to zero, and then starts ash charging and restarts the melting operation.

By tilting, the molten metal (metal) 10 is guided onto the cooling conveyor 8 through the slag gutter 3 from which the molten slag 9 is usually discharged. The molten metal (metal) 10 cooled on the conveyor 8 is collected at the end of the conveyor, and the weight of the molten metal discharged by the weighing device 22 installed here can be measured. Of molten metal weight,
The accurate measurement that is distinguished from the molten slag 9 can be accurately measured by the above method. As a result, the total weight of the molten metal 10 discharged during the tilting period is determined by the molten metal measuring device 38.
Can be found at.

On the other hand, the tilt angle of the furnace 1 can be easily obtained from the lift amount of the furnace pushing-up mechanism 25, and the weight of the molten metal left in the furnace can be known from the calculation of the tilt angle and the shape of the furnace. It is possible to know the weight of molten metal in the furnace immediately before tilting together with the amount of molten metal (metal).

Further, since the weight of the molten metal remaining in the furnace at the time of the previous tilting is known, the weight of the molten metal increased from the previous tilting to the current tilting is also known, and the ash input amount between the previous and current tilting timings is also known. The metal component contained in the ash unit weight can be obtained from the ash addition amount integrating device 33.

In the case of waste incineration ash, the composition of the waste that is the source of the ash is not constant, and the composition may change depending on factors such as the time of collection and the collection destination. The rate of increase of 10 may change. However, according to the present embodiment, as described above, by measuring and managing the metal component content per unit weight of ash for each tilt timing cycle, the metal component tends to increase during each tilt timing cycle. It is also possible to make a correction such that the tilting period input amount is decreased if it is, and the tilting period input amount is increased if it is decreasing.

The input amount correction device 39 incorporates an input amount correction circuit (program) incorporating such a logic, whereby the tilting timing can be appropriately set even when the composition of the molten ash changes.

Next, FIGS. 3 and 4 show a second embodiment of the present invention. FIG. 3 is a main part configuration diagram (1) enlarging and showing the vicinity of the electrode tip of the plasma melting furnace, and an electrical equivalent circuit (2) is shown on the right side thereof. As shown in the equivalent circuit, the slag resistance Rs is large and the metal resistance Rm is small. A hole 5a through which an inert gas (for example, nitrogen gas) serving as the plasma working gas 18 passes is formed in the center of the electrode 5 and is blown out from the tip of the electrode 5. Surface of molten slag 9 is plasma flow 1
7 and the plasma working gas 18 are not only sprayed, but also when the ash that is thrown in falls as a lump, or the components in the ash are gasified due to the high heat of the plasma, the surface is not a little wavy. There is.

As the thickness of the molten slag layer 9 becomes thinner, the thickness of the molten slag layer 9 becomes extremely thin when the surface is wavy, and sometimes the molten metal (metal) layer 10 partially forms.
It's almost exposed. In this case, the plasma current 17 from the plasma electrode 5 directly flows into the molten metal (metal) 10. In terms of electric circuit, it is equal to the electric resistance Rs of the molten slag portion becoming zero. When the DC power supply device 2 of the plasma melting furnace 1 is a constant current power supply device that controls so that a set amount of current flows, the resistance value (Rc
When + Rg + Rs + Rm) changes, the voltage applied to the melting furnace changes because a constant current flows. (Ohm's law: V = I × R)

Therefore, when the molten slag layer 9 becomes thinner and the molten slag surface becomes wavy, when the molten metal (metal) layer 10 portion appears directly below the plasma electrode 5,
Since the ratio of the slag resistance Rs to the total resistance (Rc + Rg + Rs + Rm) is relatively large, a sharp voltage drop occurs. However, this state does not last for a long time, and when the peak of the wave comes, the molten slag layer 9 intervenes and the voltage rises and returns to the original state. Hereinafter, such a voltage change is referred to as a downward spike.

FIG. 4 is a waveform graph diagram in which the voltage fluctuation of the DC voltage power supply is measured based on the equivalent circuit of FIG. 3 (2).
FIG. 4 (1) shows a case where the molten metal (metal) 10 is large, and it can be seen that a downward spike is generated. Figure 4 (2)
Indicates a case where the molten metal (metal) 10 is small, and although there is some variation, it is stable and no spike-like voltage variation occurs. Therefore, in the equivalent circuit of FIG. 3 (2), a voltmeter 40 is provided between the plasma electrode 5 and the furnace bottom electrode 6.
Is sent to the voltage fluctuation monitoring device 41, the monitoring device 41 monitors changes in the power supply voltage, and a predetermined counter signal is sent to the counting device 42 when a preset voltage fluctuation occurs. It is supposed to be released.

In the present embodiment, in order to detect the downward spike, the monitoring device 41 is set so that the voltage drop value: Vdown [V] or more, the voltage change rate: dV / dt [v / s] or more, the fall time width. T [s]
The following is set and a signal is output when there is a signal change corresponding to this condition. As an example, voltage drop value: 30 [V] or more, voltage change rate: 5 [v / s]
As described above, the reduction time width is 15 [s] or less. But,
Since these values change depending on the viscosity and properties of the material to be melted (especially electric resistance), operating voltage, operating current amount, melting treatment amount, etc., these values are merely examples and do not limit the present invention. .

The lower spike counter 42 counts and integrates the output counter signal of the voltage fluctuation monitor 41 at each tilt timing interval. Tilt timing determination device 43
Periodically fetches and stores the count value of the lower spike counting device 42. After capturing, a reset signal is output to reset the count value of the lower spike counting device 42 to zero. The determination device 43 determines the operation status, and determines the tilting timing when the number of downward spikes generated per hour during a normal ash charging operation exceeds a predetermined value. For example, when the number of downward spikes generated per hour exceeds 50 times and the state continues for 5 hours or more, it is determined that the tilting timing has come (this determining timing does not limit the present invention). . This detection signal is input to the tilt control device 35, and the subsequent processing is the same as that described in the first embodiment, so
Detailed description is omitted here.

By using such a method, the tilting timing can be detected without measuring the ash input amount. When the ash containing a large amount of metal components is temporarily melted, a sign of voltage fluctuation appears before the set ash input amount is reached, so that the tilting timing can be detected without delay.

Further, by providing the operation control device incorporating both the detection method of the first embodiment and the detection method of the second embodiment, it is possible to back up and complement each other.
A more reliable determination method and operation control device can be provided.

In the present embodiment, the incineration fly ash of the refuse incinerator and the plasma ash melting furnace that melts the residue are targeted as the objects to be melted. The present invention can also be applied to the case of another waste plasma melting furnace in which a substance containing components is melt-processed. Further, in the present embodiment, tilting is targeted as the molten metal discharging method, but the present invention can be applied to other discharging methods such as a molten metal discharging method in which a tap hole is opened and tapped from the furnace bottom. You can

[0047]

As described above, according to the first aspect of the present invention,
It is possible to accurately and accurately predict the deposition of molten metal in the melting furnace without installing a sensor in the furnace, which allows the operator to determine the tilt operation start time for discharging molten metal from the furnace. You can learn without relying on your experience and intuition. In this case, by incorporating the inventions of claims 2 and 4, even if the property of the material to be melted is seasonally changed or changes with time, it can be corrected from the discharged molten metal amount and the accuracy is high. The tilt start time can be calculated. These inventions are not limited to the plasma waste melting furnace, but can be applied to other internal melting furnaces and electric arc furnaces.

Further, according to the second aspect of the invention, no special sensor for detecting the weight of molten metal slag is required, and the molten metal is deposited due to the voltage fluctuation of the DC voltage power source applied to the plasma electrode. It is possible to detect accurately and reliably, and to know the start time of the tilting operation for discharging molten metal without relying on the experience and intuition of the operator, as well as temporary property changes of the melted object. Therefore, it is possible to detect optimal waste input control and abnormality determination.

Further, according to the third aspect of the present invention, by using the above two aspects together, it is possible to back up and complement each other, and it is possible to provide a more reliable discharge timing determination and operation control device.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an operation control device for a plasma ash melting furnace according to a first embodiment of the present invention.

FIG. 2 is an operation explanatory view showing a tilting operation of the furnace.

FIG. 3 is a diagram illustrating a second embodiment of the present invention,
(1) is an enlarged schematic view of the vicinity of the electrode tip of the plasma melting furnace, and (2) shows an electrical equivalent circuit.

FIG. 4 shows a graph of a voltage fluctuation waveform obtained by measuring the voltage fluctuation of the DC voltage power supply based on the equivalent circuit of FIG. 3 (2). The case where the amount of molten metal (metal) is small is shown.

FIG. 5 is an overall configuration diagram of a plasma ash melting furnace according to a conventional technique.

[Explanation of symbols]

1 melting furnace 2 DC power supply 3 Debris gutter 5 Main electrode (plasma electrode) 6 Furnace bottom electrode 7 slot 8 Conveyor 9 Molten slag 10 Molten metal 12 Ash feeding device 14 Input amount integration display 15 Weight indicator 21 Input amount measuring device 22 Weighing device 25 furnace lifting mechanism 31 Manual setting device 32 Tilt timing input amount storage device 33 Input amount integrating device 34 Comparator 35 Tilt control device 37 Operation panel 38 Molten metal measuring device 39 Input amount correction device 40 Voltmeter 41 Voltage fluctuation monitoring device 42 Downward spike counter 43 Tilt timing determination device

Front page continuation (72) Inventor Kyoko Wada 1-1-1, Wadasaki-cho, Hyogo-ku, Kobe Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (56) Reference JP-A-10-332268 (JP, A) JP-A 10-185155 (JP, A) JP 10-246415 (JP, A) JP 3-127486 (JP, A) JP 60-216112 (JP, A) JP 61-168719 (JP, A) JP 57-184820 (JP, A) JP 10-332123 (JP, A) JP 9-280536 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) ) F23G 5/50 F23G 5/00 115 F23J 1/00 F23J 1/08 F27B 3/19 F27B 3/28

Claims (7)

(57) [Claims] 1. A waste melting treatment furnace which discharges molten metal accumulated under the molten slag by a predetermined means in each discharge cycle for measuring the difference between slag and molten metal. The amount of waste to be put into the furnace in the cycle is measured, and when the measured total amount of waste input in the current cycle exceeds a predetermined predetermined value, it is determined that the discharge time of the molten metal has come ,
The operation control method for a plasma melting furnace, wherein the predetermined value is corrected for each discharge cycle . 2. The next molten metal discharge time is determined by measuring the molten metal amount at the time of discharging the molten metal for each cycle and determining the molten metal amount per waste input amount based on at least the measured value of the current cycle. The operation control method for a plasma melting furnace according to claim 1, wherein the specified value is corrected. 3. A waste melting treatment in which the waste is melted and the molten slag is discharged from a slag spout, and the molten metal accumulated under the molten slag is discharged by a predetermined means in each arbitrarily set discharge cycle. In the furnace, compare the means to measure the amount of waste input into the furnace in the current cycle after the last molten metal discharge and the measured total amount of waste input in the current cycle to a predetermined value. and means, when comprising a discharge control means for setting a discharge time of the molten metal on the basis of a signal from said comparing means DOO
In addition, the operation control device for a plasma melting furnace , wherein the predetermined value is corrected for each discharge cycle . 4. A means for measuring the amount of molten metal at the time of discharging molten metal in each cycle, a means for measuring the amount of waste to be charged into the furnace in each cycle, and the two detection means. The operation control device for a plasma melting furnace according to claim 3, further comprising a correction unit that corrects the specified value that determines the next molten metal discharge timing based on the detection signal. 5. The waste is melted by plasma discharge while being supplied with a constant current by a direct current power supply device having a constant current control function between the plasma electrode inserted from the top of the furnace and the bottom electrode, and melted from the outlet. In the waste melting furnace, which discharges the slag and discharges the molten metal accumulated under the molten slag by a predetermined means in each discharge cycle set arbitrarily, the voltage fluctuation during operation between the plasma electrode and the bottom electrode By monitoring and detecting instantaneous voltage fluctuations in the negative direction and counting, and when the number of occurrences per unit time exceeds the specified number of times for a certain period of time, the molten metal discharge timing comes. A method for controlling the operation of a plasma melting furnace, which is characterized in that 6. The waste is melted by plasma discharge while being supplied with a constant current by a direct current power supply device having a constant current control function between the plasma electrode inserted from above the furnace and the bottom electrode, and melted from the outlet. In the waste melting furnace, which discharges the slag and discharges the molten metal accumulated under the molten slag by a predetermined means in each discharge cycle set arbitrarily, the voltage fluctuation during operation between the plasma electrode and the bottom electrode Voltage fluctuation detection means for detecting, counting means for detecting and counting instantaneous voltage fluctuations in the negative direction from the voltage fluctuations, and the number of times of occurrence of the instantaneous voltage fluctuations per unit time exceeds a prescribed number of times. An operation control device for a plasma melting furnace, comprising: a judgment means for judging that a molten metal discharge time has come when the state continues for a predetermined time. 7. The waste material is melted by plasma discharge while being supplied with a constant current by a DC power supply device having a constant current control function between the plasma electrode inserted from above the furnace and the bottom electrode, and melted from the outlet. In a waste melting treatment furnace that discharges slag and discharges the molten metal accumulated under the molten slag by a predetermined means in every discharge cycle set arbitrarily, in the furnace in the current cycle after the last discharge of molten metal The first determination means for determining the discharge timing of the molten metal based on the total amount of waste to be charged into the furnace, and the discharge timing of the molten metal by the instantaneous negative voltage fluctuation between the plasma electrode and the bottom electrode of the furnace. And a second determination means for determining the discharge timing of the molten metal based on the determination signal of either or both of them. Control device.