JP2001304526A - Automatic control method for surface melting furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface melting furnace for a workpiece such as refuse incineration residues wherein the article can be melted automatically, stably, and successively with high efficiency without causing the sharp cost increase of a controller. SOLUTION: An automatic control method for a surface melting furnace is provided. The surface melting furnace A is adapted such that a melting object article W supplied into a furnace body 1 from a supply apparatus 5 is melted in succession from a surface side with the aid of a combustion flame of a melting burner 6. In the surface melting furnace A, an image pickup apparatus equipped radiation thermometer 18 is provided o a ceiling wall 1d of the furnace body 1 for monitoring a molten part Q of the article W supplied into the surface. On the basis of a temperature detection signal St and an image detection signal Sc from the pickup apparatus equipped radiation thermometer 18 there are achieved any one or both of automatic driving control of the supply apparatus 5 and automatic combustion control of the melting burner 6 through the controller 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a surface melting furnace for melting and treating incineration residues and fly ash discharged from a refuse incinerator, sewage sludge, crushed incombustibles, and the like.
The melting part of the material in the furnace is monitored by a radiation thermometer with an imaging device provided on the ceiling wall of the furnace body, and the supply amount of the material to be melted and the combustion of the melting burner are determined using the temperature detection signal and the image detection signal. The present invention relates to a method for automatically controlling a surface melting furnace, which enables stable continuous operation of the surface melting furnace by automatically adjusting the amount.

[0002]

2. Description of the Related Art Molten materials such as incineration residues and fly ash discharged from a refuse incinerator are usually landfilled. However, it is becoming increasingly difficult to secure landfill sites year by year, and there is a demand for reducing the volume, harmlessness, and effective use of molten materials. Thus, in recent years, attention has been paid to a melting treatment capable of significantly reducing the volume and detoxifying incineration residues and fly ash, and has been put to practical use. By melting and solidifying incineration residues, etc., the volume is reduced to 1/2 to 1/3, and complete decomposition of dioxins, prevention of elution of harmful substances such as heavy metals, etc. become possible, and concrete filler materials, roadbed materials, This is because it can be reused as blocks and extend the life of the final landfill site.

[0003] For melting treatment of incineration residues and the like, melting furnaces of various structures have been conventionally used. FIG. 4 is a schematic longitudinal sectional view showing an example of a conventional surface melting furnace A of this type.
The surface melting furnace A supplies the material W to be melted from two directions (left and right directions) or four directions (front and rear left and right directions) into the furnace, and melts the material W to be melted from the surface side to form a molten surface. 2
It has a planar structure or a four-plane structure. That is, a furnace body 1 having a slag tap 1b formed at the center of a furnace bottom 1a.
And a hopper 2 respectively disposed at the left and right positions (or front and rear left and right positions) of the furnace main body 1, and a material W to be melted which is rotatably disposed above the furnace main body 1 and supplied from the supply conveyor 3. Distribution supply device 4 for uniformly distributing and supplying to each hopper 2
A supply device 5 provided at a lower position of each hopper 2 and sequentially supplying the melted material W in the hopper 2 into the furnace;
And one or more melting burners 6 arranged on the ceiling wall 1c for heating and melting the material to be melted W from the surface side, and molten slag arranged below the furnace body 1 and flowing down from the slag tap 1b. A cooling water tank 7 for water-cooling the S, and a slag conveyor 8 disposed in the cooling water tank 7 for discharging the granulated slag T
And so on.

In FIG. 4, reference numeral 9 denotes a lower space of the furnace;
a is a peripheral wall forming a lower space of the furnace, 10 is a gas outlet, 1
1 is a view window for the inside of the furnace, 12 is a view window for the lower part of the furnace, 13 is an industrial television (ITV), 14 is an image processing device, 15 is a gas thermometer, 16 is a thermocouple, 17 is a radiation thermometer, and Q is This is a melting portion of the material to be melted W.

The material to be melted W is introduced into each hopper 2 by a distribution and supply device 4 controlled by a signal from a level sensor (not shown) disposed in each hopper 2, and is maintained in the furnace while maintaining a constant level. And each hopper 2 is hermetically sealed. The material to be melted W charged into each hopper 2 is
As will be described later, the supply device 5 sequentially extrudes the inside of the furnace, and the surface has a substantially mortar-shaped inclined surface centered on the slag tap 1b (the angle of the inclined surface is an angle of repose or an angle close to the angle of repose of the material to be melted W ) Is deposited on the furnace bottom 1a to form a fusion zone Q.

The material W to be melted deposited on the furnace bottom 1a is sequentially heated and melted from the front side by the combustion flame from the melting burner 6, and becomes a film-like molten slag S. The molten slag S flows down the mortar-shaped inclined surface to form a slag tap 1b.
From the cooling water tank 7, cooled and solidified by the cooling water to form granulated slag T, and then discharged by the slag conveyor 2. Also, the high-temperature flue gas G generated in the furnace
Is discharged from the slag tap 1b together with the molten slag S to the outside of the furnace through the furnace lower space 9 and the gas discharge port 10, and is provided with a flue, an air preheater, an exhaust gas treatment device, etc. (all not shown).
It becomes a clean gas after being discharged to the atmosphere.

More specifically, in the operation of the surface melting furnace A, first, the supply amount of the material W to be melted by the supply device 5 and the combustion amount of the combustion burner 6 are set to predetermined values. drive. Thereafter, monitoring of the flowing down state of the molten slag S from the slag tap 1b by the ITV 13, monitoring of the amount and quality of the granulated slag T, monitoring of the exhaust gas temperature by the gas thermometer 15, and monitoring of the furnace through the observation window 11 through the furnace. The state of melting of the material W to be melted in the furnace is ascertained with reference to the results of visual observation and the like. Then, the previously set value of the supply amount of the molten material and the set value of the melting burner 6 are appropriately adjusted according to the grasped molten state, thereby maintaining the molten state of the molten material W in the optimum state. We operate the surface melting furnace.

However, the setting change of the supply amount of the melted material W and the combustion amount of the melting burner 6 is performed by a judgment based on each operator's experience, and there is a great individual difference in control by the operator. In addition to the above, there is a problem that the response in the operation control of the surface melting furnace is extremely poor.

Further, in order to eliminate the above-mentioned problems, the flow-down state of the molten slag S from the slag tap 1b is digitized using the image processing device 14, and the supply of the material W to be melted is performed using the image processing signal. Method for automatically controlling the amount and the combustion amount of the molten burner 6, the thermocouple 16 and the radiation thermometer 17
A method has been developed for automatically controlling the supply amount of the material to be melted W and the combustion amount of the melting burner 6 based on the detected value of the furnace temperature.

However, the former method using the image processing device 14 has a problem that an expensive camera and a computer are required, and the cost of the control device is greatly increased. This method logically monitors the temperature distribution near the slag tap 1b instead of monitoring the state of the molten portion Q of the material W to be melted in the furnace. There is a problem that the signal cannot be used as it is for controlling the supply amount of the melt W or the combustion amount of the melting burner 6.

In the latter method using the detected value of the furnace temperature, the thermocouple 16 is frequently damaged, the reliability of the detected furnace temperature is low, and the replacement cost and the repair cost are high. There is a disadvantage called. In addition, in the control using only the radiation thermometer 17, since only the temperature within the visual field range can be detected, the control becomes so-called excessive control,
Alternatively, a temperature significantly lower than the actual furnace temperature is often displayed as a detected value. As a result, a malfunction occurs in the operation control, and there is a problem that high-precision and stable automatic control cannot be performed.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems in a conventional surface melting furnace for incineration residues and the like, namely,
The operator judges the operation state of the surface melting furnace from the monitoring results of the falling state of the molten slag S, the exhaust gas temperature, the melting state in the furnace, and the like, and based on this, the supply amount of the melted material W and the combustion amount of the molten burner. In the method of manually adjusting the surface melting furnace, the operation state of the surface melting furnace greatly changes depending on the skill of the operator, and the stable and efficient operation of the surface melting furnace cannot be performed. On the other hand, an automatic operation method using a radiation thermometer or the like causes an increase in equipment costs and repair costs of the control device, and is intended to solve the problem that high-precision and stable automatic control cannot be performed. The melting state of the in-furnace melting section Q is monitored and the temperature is detected using a radiation thermometer with an imaging device, and the supply amount and melting of the material to be melted are determined by an image detection signal and a temperature detection signal from the radiation thermometer with the imaging device. Controls burner combustion It allows there is provided an automatic control method for the surface melting furnace to be stably operated with high efficiency the surface melting furnace using a less expensive control system.

[0013]

According to the first aspect of the present invention, there is provided a surface melting furnace in which a molten material supplied into a furnace body by a supply device is sequentially melted from the surface side by a combustion flame of a melting burner. And a radiation thermometer with an imaging device for monitoring the melting portion of the material supplied into the furnace on the ceiling wall of the furnace body, and is controlled by a temperature detection signal and an image detection signal from the radiation thermometer with the imaging device. A basic configuration of the present invention is to perform one or both of the automatic drive control of the supply device and the automatic combustion control of the melting burner via a device.

According to a second aspect of the present invention, in the first aspect of the present invention, a lower limit value for control is provided to a temperature detection signal from the radiation thermometer with the imaging device, and the temperature detection signal is lower than the lower limit value. , The automatic drive control of the supply device and the automatic combustion control of the melting burner are canceled and an alarm signal is transmitted.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic longitudinal sectional view of a surface melting furnace to which the present invention is applied, FIG. 2 is a configuration diagram of a radiation thermometer with an imaging device used in the present invention, and FIG. 3 is a control system of the surface melting furnace to which the present invention is applied. FIG. Note that in FIGS. 1 to 3,
The same parts and members as those in FIG. 4 are denoted by the same reference numerals.

In FIG. 1, A is a surface melting furnace, W is a material to be melted, S is a molten slag, T is a granulated slag, G is a combustion exhaust gas, Q is a melting portion in the furnace, 1 is a furnace body, 2 is a hopper, 3 is a supply conveyor, 4 is a distribution supply device, 5 is a supply device for the material to be melted, 5a is a drive unit of the supply device, 6 is a melting burner, 6a
Is a combustion part of a melting burner, 7 is a cooling water tank, 8 is a slag conveyor, 9 is a lower space of the furnace, 10 is a gas outlet, 11 is a peephole in the furnace, 12 is a peephole in the lower part of the furnace, 15 is a gas thermometer,
18 is a radiation thermometer with an imaging device, 18a is a radiation thermometer, 1
8b is a CCD camera, St is a temperature detection signal, Sc is an image detection signal, 19 is a control device, Cd is a supply amount control signal, C
f is a combustion amount control signal. Note that the configuration of the surface melting furnace A itself is publicly known and is substantially the same as the case of FIG. 4 described above.

On the ceiling wall 1c of the furnace main body 1, a plurality of radiation thermometers 18 with image pickup devices are mounted on the furnace bottom 1a, that is, in the direction of the melting portion Q of the material W to be melted. The temperature detection signal St of Q and the image detection signal Sc of the fusion zone Q are sent from the radiation thermometer 18 with the imaging device to the control device 19, respectively. The radiation thermometer 18 with the image pickup device is an integral one of a radiation thermometer 18a and a CCD camera 18b as shown in FIG. 2, and the radiation thermometer 18a detects the temperature of the fusion zone Q, The image of the fusion zone Q is monitored by the CCD camera 18b. Further, the temperature detection and the image monitoring are alternately and alternately performed at regular time intervals, thereby checking in parallel whether or not the visual field of the radiation thermometer accurately matches the fusion zone Q.
Further, the radiation thermometer 18a and the CCD camera 18b are stored in a casing 18c, and the inside of the casing 18c is forcibly cooled by an airflow Ac.

From the radiation thermometer 18 with the imaging device to the control device 1
When the temperature detection signal St and the image detection signal Sc are input to the control device 9, the control device 19 outputs the input temperature detection signal St.
And the image detection signal Sc is compared with a preset reference temperature signal and reference image signal. If the comparison difference between the two exceeds a set value, the drive control unit of the supply device 5 Control signals Cd and Cf in a direction to reduce the comparison difference are transmitted to one or both of the combustion control unit 5a and the combustion control unit 6a of the melting burner 5. As a result, one or both of the supply amount of the melt W and the fuel combustion amount are automatically controlled.

In the control device 19, a lower limit value for control is set for the temperature detection signal St from the radiation thermometer 18 with an image pickup device, and the temperature detection signal St is set to be equal to or less than the lower limit value. , The automatic control based on the temperature detection signal St is released and the alarm signal Sa is transmitted.
In this way, by setting the control lower limit for the temperature detection signal St, it is possible to almost completely avoid operation control troubles caused by erroneous temperature detection that frequently occurs in the radiation thermometer 18a. become.

When the alarm signal Sa is transmitted from the control device 19, the operator visually confirms the image of the CCD camera, and checks the state of the melted portion Q in the furnace and the slag tap 1b through the view windows 11 and 12. The state of the molten slag S flowing down from the container is visually checked. If no abnormality is found in the state of the melting process, the temperature detection signal S
The reset of the automatic control by t is reset, and the control system is returned to the state of the automatic control operation. If an abnormality is found in the state of the melting process, the operation is switched to the manual control, and when the state of the melting process is returned to the normal state, the operation is switched to the automatic control operation.

[0021]

According to the present invention, the temperature of the melting portion of the object to be processed is continuously detected and monitored by an image using a radiation thermometer with an image pickup device, and the melting state of the melting portion is detected by a temperature detection signal and a temperature detection signal. In addition to outputting the image detection signal to the control device, one or both of the supply amount of the material to be melted and the combustion amount of the melting burner are automatically controlled based on the two signals.
As a result, the field of view of the radiation thermometer can be confirmed by the image of the CCD camera, and the excessive control and error in control that often occur when only the radiation thermometer is used can be almost completely prevented. Automatic control of the surface melting furnace becomes possible.

Further, since the melting portion of the material to be melted is directly monitored by the radiation thermometer with the image pickup device, the response of the control can be enhanced. Thereby, even if the property of the material to be melted changes during operation, the stable operation of the surface melting furnace becomes possible, and a high-quality granulated slag free of unmelted material can be obtained.

Further, by directly monitoring the melted portion of the material to be melted, it is possible to stably supply the material to be melted W, thereby suppressing wear of the refractory on the furnace wall due to insufficient supply of the material to be melted and excessive use of fuel. be able to.

In addition, there is no error caused by breakage of the thermocouple or the like as in the case of the conventional automatic control method using a thermocouple, and stable automatic operation of the surface melting furnace can be performed. INDUSTRIAL APPLICABILITY As described above, the present invention has an excellent practical effect that a material to be melted can be stably melted with high efficiency without causing a significant increase in the cost of the control device.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view of a surface melting furnace to which the present invention is applied.

FIG. 2 is a configuration diagram of a radiation thermometer with an imaging device used in the present invention.

FIG. 3 is a control system diagram of a surface melting furnace to which the present invention is applied.

FIG. 4 is a schematic longitudinal sectional view of a conventional surface melting furnace.

[Explanation of symbols]

1 is a furnace body, 1a is a furnace bottom, 1b is a slag tap, 1c is a ceiling wall, 2 is a hopper, 3 is a supply conveyor, 4 is a distribution supply device, 5 is a supply device, 5a is a driving unit, 6 is a melting burner,
6a is a combustion part, 7 is a cooling water tank, 8 is a slag conveyor, 9
Is a furnace lower space, 9a is a peripheral wall, 10 is a gas outlet, 11 is a view port in the furnace, 12 is a view port in the lower furnace, 15 is a gas thermometer, 18 is a radiation thermometer with an imaging device, 18a is a radiation thermometer, 18b is a CCD camera, 19 is a control device, A is a surface melting furnace, W is a material to be melted, S is a molten slag, T is a granulated slag, G is a combustion exhaust gas, Q is a melting part, St is a temperature detection signal, Sc Is an image detection signal, Cd is a supply amount control signal, Cf
Is a combustion amount control signal, and Sa is a warning signal.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23G 5/00 115 F23G 5/00 115A F27B 1/28 F27B 1/28 F27D 21/00 F27D 21/00 D 21/02 21/02 (72) Inventor Tomohiko Hirao 2-33, Kinrakuji-cho, Amagasaki-shi, Hyogo F-term in Takuma Co., Ltd. (reference) 3K061 AA05 AB03 AC01 BA02 CA01 DA13 DB02 DB19 DB20 3K062 AA05 AB03 AC01 BA02 BB02 CA03 CA08 CB03 DA01 DB01 DB13 4K045 AA04 BA07 BA10 DA04 4K056 AA05 BA01 BB01 CA20 FA03 FA12 FA23

Claims (2)

[Claims] 1. A surface melting furnace in which a material to be melt supplied into a furnace main body by a supply device is sequentially melted from the front side by a combustion flame of a melting burner. A radiation thermometer with an imaging device for monitoring the melted portion of the supplied melt is provided, and automatic driving control of the supply device is performed via a control device by a temperature detection signal and an image detection signal from the radiation thermometer with the imaging device. And / or an automatic combustion control of the melting burner. 2. A lower limit value for control is provided to a temperature detection signal from a radiation thermometer with an imaging device, and when the temperature detection signal is equal to or less than the lower limit value, automatic driving control of a supply device and automatic control of a melting burner are performed. The method for automatically controlling a surface melting furnace according to claim 1, wherein the combustion control is canceled and an alarm signal is transmitted.