JP3351323B2 - Waste incineration apparatus and method for suppressing generation of dioxins - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refuse incineration apparatus and method for suppressing generation of dioxins.

[0002]

2. Description of the Related Art The generation and emission of extremely toxic dioxins has been confirmed in incinerators for municipal waste or industrial waste. Conventionally, dioxins are a type of hydrocarbon and are thought to be generated from unburned components and chlorine in the incineration process. Therefore, measure the amount of carbon monoxide (CO) that is an indicator of flammability, that is, the generation of unburned components. And this C
It is common practice to perform combustion control in a direction to reduce the amount of O generation. An example of such a combustion control technique using the amount of generated CO as an index is disclosed in Japanese Patent Application Laid-Open No. 5-99411 (hereinafter referred to as Prior Document 1), and the combustion is controlled so that the amount of generated CO is reduced. It is described that the effect of suppressing the generation of unburned components such as dioxins can be improved.

A refuse incinerator to which the technology disclosed in the above-mentioned prior art document 1 is applied determines whether the amount of water sprayed into the combustion furnace or the amount of primary air supplied to the combustion furnace is excessive or insufficient based on the furnace temperature and the amount of CO generated. A control amount calculating section for generating each supply control signal, and a spray water amount and 1
It is composed of supply control means for adjusting the amount of secondary air.

[0004]

However, the use of the amount of generated CO as an index of combustion control as in the refuse incinerator disclosed in the above-mentioned prior art document 1 may be correct in a limited case. , Is not necessarily correct in all cases. That is, it is impossible in principle for the following reasons. Unburned components generated by refuse combustion are roughly classified into aliphatic compounds and aromatic compounds, and those obtained by chlorinating these compounds. Generally or theoretically, for example, the bond dissociation energy of a carbon-carbon bond is smaller in an aliphatic compound than in an aromatic compound due to resonance stabilization of the aromatic compound. In other words, aliphatic compounds are easier to cleave bonds,
It means that it is easy to burn in the burning process and the like. Therefore, under a certain primary air amount, if the furnace temperature becomes high due to fluctuations in the quality of the refuse and the combustibility is improved, the primary air amount becomes insufficient and the CO concentration increases. In this case, the burnable aliphatic compound burns preferentially, and the aromatic compound remains relatively. On the other hand, similarly, when the furnace temperature becomes low under a constant primary air amount and the combustibility decreases, incomplete combustion occurs and the CO concentration increases. In this case, it is assumed that the concentration of both the aliphatic compound and the aromatic compound becomes high. That is, when the CO concentration starts to slightly increase from the minimum value in a state in which the furnace temperature is high, the CO concentration increases as a result of a shortage of primary air due to preferential combustion of the aliphatic compound. Therefore, it is supposed that the contribution of decomposition and combustion of aromatic compounds such as dioxins is relatively small. The increase in the CO concentration at this time is a measure of the primary air amount shortage, and is not necessarily an index of the generation or increase of unburned components such as aromatic compounds.

Further, when only the CO concentration is used as an index,
Measurement of the CO concentration is easy. However, it does not include any information on the chlorination reaction of aromatic compounds. Therefore, direct information on chlorinated aromatic compounds such as dioxins cannot be obtained. Therefore, controlling the combustion to an appropriate amount with a small amount of CO generation generally reflects a decrease in the generation amount of unburned components. In other words, at a high unburned amount generation level in the refuse incinerator several years ago, the combustion control using the CO concentration as an index is effective. However, at the extremely low level of unburned substances generated by recent advanced waste incinerators, the control of combustion using CO concentration as an index further suppresses the generation of unburned substances, especially chlorinated aromatic compounds such as dioxins. And reduction cannot be achieved.

The present invention has been made in view of the above points, and provides a refuse incineration apparatus and method capable of achieving further suppression and reduction of dioxins which could not be achieved by combustion control using CO concentration as an index. I do.

[0007]

[0008]

[0009]

[0010]

[0011]

[0012]

SUMMARY OF THE INVENTION According to the present invention, there is provided an internal combustion chamber.
A combustion furnace that burns garbage in the air and a small amount of
Direct measurement of the amount of at least one type of dioxins generated
Ioxins measurement means and oxygen concentration in combustion furnace
Oxygen measuring means for measuring the temperature inside the furnace of the combustion furnace
Temperature measuring means, dioxin measuring means, oxygen measuring means
And the furnace temperature measuring means
At least one type of dioxins, oxygen concentration, and
And the amount of waste supplied to the combustion furnace based on
And / or control by judging excess or deficiency of secondary combustion air amount
An arithmetic unit that generates a signal, and the control signal
Emissions of at least one dioxin
So that the waste supply and / or secondary combustion air
Of dioxins having supply amount adjusting means for adjusting
A waste incinerator that suppresses the generation of waste
(A) the concentration of dioxins is high and the oxygen concentration
If the temperature is high or the furnace temperature is low,
And / or decrease the amount of secondary combustion air.
(B) the concentration of dioxins is
High and low oxygen concentration or high furnace temperature
Separately reduce waste supply and / or secondary fuel
Generates a control signal to increase the amount of baked air
A waste incinerator to control the generation of dioxins
Offer .

[0013] The present invention also relates to a method for removing dust in combustion air.
Furnace that burns water and water spray that sprays water into the furnace
Means and at least one dioxin in the combustion furnace
Dioxin measurement means for directly measuring the amount of
A furnace temperature measuring means for measuring the furnace temperature of the kiln;
At least one daiuki which is measured by the toxins measuring means;
Based on the amount of synths generated, the amount of waste
And / or the secondary combustion air amount is determined to be excessive or insufficient.
At least one kind of dioxygen measured by the synth measuring means
Of the temperature of the furnace and the amount of
Based on the data, it was determined whether the amount of water spray
And an arithmetic unit for generating a control signal, and
The emission of at least one dioxin in the combustion furnace
Waste supply and / or secondary so that production is reduced
Supply amount adjusting means for adjusting the combustion air amount and the water spray amount.
Garbage incinerator that controls the generation of dioxins
Wherein in the arithmetic unit, (a) dioxins
If it is determined that the concentration of is high and the furnace temperature is low,
Generate a control signal to reduce the amount of water spray, and
Determined that the concentration of xins is low and the furnace temperature is high
To generate a control signal to increase the amount of water spray when
Waste incineration that suppresses the generation of dioxins characterized by waste
Provide equipment .

Further , in the present invention, the dioxy
Means for measuring at least one type of the dioxins
Preference is given to measuring emissions in real time
No.

Further, the present invention relates to a method in which combustion air is introduced into a combustion furnace.
This is a refuse incineration method that burns garbage in a combustion furnace.
Of at least one type of dioxins in the combustion furnace
Measuring the oxygen concentration in the furnace and the furnace temperature.
At least one type of dioxins, oxygen concentration, and
Waste to the combustion furnace based on the measured
Of the amount of secondary combustion air supplied to the combustion furnace and / or
Determining the excess or deficiency, and the waste supply amount and / or 2
Based on the determination of excess or deficiency of the next combustion air amount,
The amount of at least one type of dioxins generated will decrease
Adjust the amount of waste and / or the amount of secondary combustion air
The generation of dioxins
A refuse incineration method, wherein in the determining step, (a)
Dioxins with a high oxygen concentration
Or if it is determined that the furnace temperature is low,
It is determined that the amount of foot and / or secondary combustion air is excessive
(B) the concentration of dioxins is high and the oxygen concentration
If the temperature is low or the furnace temperature is high,
Insufficient supply and / or insufficient secondary combustion air
The generation of dioxins characterized by
Provide a method to control refuse incineration .

[0016] The present invention also provides a method in which combustion air is introduced into a combustion furnace.
This is a refuse incineration method that burns garbage.
Amount of at least one type of dioxins generated and in the furnace
Measuring the temperature and at least one type of dioxin
Based on the measured data on the amount of waste generated
Of the amount of secondary combustion air supplied to the combustion furnace and / or
Determine excess or deficiency and generate at least one type of dioxin
Based on the measurement data of the production amount and the temperature inside the furnace,
The process of determining whether the water spray amount is
And / or based on the determination of excess or deficiency of the secondary combustion air amount,
Amount of at least one type of dioxins generated in the combustion furnace
Waste and / or secondary combustion so that
Adjust the amount of air, based on the determination of excess or deficiency of the amount of water spray,
Amount of at least one type of dioxins generated in the combustion furnace
Adjusting the amount of water spray so as to reduce
A waste incineration method that controls the generation of dioxins
In the determination step, (a) the concentration of dioxins
If the temperature is high and the furnace temperature is low,
It is determined that the amount of fog is excessive, and (b) the concentration of dioxins
Temperature is low and the furnace temperature is high,
Daioki characterized by determining that the amount of fog is insufficient
Provide a refuse incineration method that suppresses the generation of synths .

[0017]

[0018]

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the refuse incineration apparatus of the present invention. The refuse incinerator 10 according to the present embodiment includes a combustion furnace 11 for burning refuse in combustion air inside. Although the furnace type of the combustion furnace 11 is not particularly limited, for example, a stoker type or a fluidized bed type is used.

The combustion furnace 11 is provided with dioxin measuring means 12, oxygen (O ₂ ) concentration measuring means 101 and / or furnace temperature measuring means 102. The measuring means 12 directly measures the amount of at least one type of dioxins generated in the combustion furnace 11. Dioxins are a general term for a total of 210 homologs / isomers of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran. The measuring means 12 for directly measuring the amount of dioxins generated is preferably a real-time automatic analyzer (rapid automatic analyzer) capable of measuring substantially in real time. Further, it is preferable to use a recent waste incinerator, that is, a device capable of measuring dioxins even at a very low concentration level such as a dioxin countermeasure furnace. Oxygen concentration and furnace temperature can be factors in estimating the cause of incomplete combustion. Further, it is preferable that the oxygen concentration measuring means 101 and the furnace temperature measuring means 102 can be measured substantially continuously as usually used.

The above conditions can be achieved, for example, by the following measuring means. That is, it is an application of laser multiphoton ionization mass spectrometry. In this laser multiphoton ionization mass spectrometer, a gas sample is introduced into a vacuum through a small-diameter nozzle, and cooled to near absolute zero by adiabatic expansion. This is called a supersonic molecular jet. In this state, molecular motion such as vibration and rotation of the molecule is suppressed, so that ionization occurs only by laser irradiation of a very narrow wavelength corresponding to the molecular structure of each compound. Therefore, if the mass spectrometer is connected, only the ionized compound molecules proceed to the mass spectrometer and are detected. Therefore, even in an exhaust gas sample in which various compounds coexist, without being affected by other compounds,
Compounds to be measured can be separated and detected (quantitative). here,
As the laser, a dye laser excited by a yag laser or an excimer laser, a titanium sapphire laser, or an optical parametric laser, that is, an ultraviolet variable laser can be used.

The mass spectrometer is not particularly limited, and may be a quadrupole type, a double focusing type, a time-of-flight type, or the like, but is preferably a time-of-flight type in consideration of operability and stability. Usually, it can be performed in milliseconds to hundreds of microseconds for introduction, nanoseconds to hundreds of femtoseconds for laser irradiation, and tens to hundreds of microseconds for detection of a time-of-flight mass spectrometer. Since measurement can be performed in a maximum of 10 milliseconds or less even when the whole is combined, real-time measurement becomes possible.

The refuse incinerator 10 includes the above-described measuring means 1
2, monitor the amount of dioxins, oxygen concentration and / or furnace temperature measured in 101 and / or 102, and operate the waste incinerator 10 based on the monitoring result, for example, the amount of waste supplied, combustion Control means is provided for changing the amount of air, the amount of water spray, and the moving speed of each grate in the case of the stalker method. In other words, the control means comprises measuring means 12, 101 and / or 10
Based on the amount of dioxins generated, the oxygen concentration and / or the furnace temperature measured in 2, the factors that are correlated with the combustion of the refuse in the refuse incinerator 10, for example, the excess of the refuse supply amount, the combustion air amount, etc. Judge the shortage and make adjustments to make them appropriate.

In this embodiment, a case where the amount of waste supplied (speed) and the amount of combustion air are adjusted will be described. The dioxin measuring means 12 includes an arithmetic unit 13 including the measuring means 1.
2, 101 and 102 are connected so as to be able to transmit the data output from them. The arithmetic unit 13 includes at least one dioxin (for example, 2,
Data on the amount of generated 8-dichlorodibenzofuran), data on the oxygen concentration in the combustion furnace 11 measured by the measuring means 101 and / or data on the furnace temperature measured by the measuring means 102 (hereinafter collectively measured) Volume data). The calculation unit 13 determines a factor correlated with the combustion of the refuse in the combustion furnace 11, for example, an excess or deficiency of the refuse supply amount or the combustion air amount, based on the measured amount data, and generates a control signal. If the combustion furnace 11 has a water spray mechanism for controlling the furnace temperature, the combustion furnace is connected so that the control signal generated by the arithmetic unit 13 can be transmitted, and has a correlation with the combustion of refuse. It is also possible to provide a means for adjusting the amount of water sprayed on 11.

The refuse supply amount adjusting means 14 adjusts, for example, a refuse hopper charging interval for charging refuse into the combustion furnace, a dust supply pusher speed for supplying the refuse to the grate, and a combustion speed of the refuse on the grate. It may be a refuse supply means capable of adjusting the amount of refuse in the combustion furnace 11 and the combustion state, such as a grate speed. The combustion air amount adjusting means 15 is, for example,
When the primary combustion air and / or the secondary combustion air is supplied into the combustion furnace 11 by a pump, the primary combustion air and / or
It may be a regulating valve provided in a pipe for conveying the next combustion air. The water spray amount adjusting means 16 may be, for example, an adjusting valve provided on a pipe that conveys water when the water is supplied into the combustion furnace 11 by a pump.

Since the refuse combustion furnace process is a multivariable interference system having non-linear characteristics as arithmetic means for generating control signals for these adjusting means, it is possible to apply non-linear control and fuzzy control. Control is possible. In particular, the fuzzy control has a feature that a control rule can be described linguistically and parameter adjustment is easy.

As a specific example, Table 1 shows a procedure for controlling / adjusting the amount of waste and / or the amount of combustion air from the measured amount data by the calculation unit 13 and a specific calculation method thereof. First, it is sequentially determined whether the current combustion state satisfies the conditions shown in the state quantities in Table 1. When these conditions are satisfied, the control shown in the operation unit of Table 1 is executed. As a result of the execution of this control, according to the increment or decrement set in advance for each condition, the waste supply amount adjusting means 14
And / or adjust the combustion air amount adjusting means 15.

[0028]

[Table 1]

In Table 1, it is assumed that at least one data of the oxygen (O ₂ ) concentration and the furnace temperature has been taken into the arithmetic unit 13. Further, (1) of the operation unit in Table 1 is when the operation amount is only the combustion air amount, (2) is when the operation amount is only the waste supply amount, and (3) is the operation amount is the combustion air amount and the waste supply amount. This is the adjustment method at the time.

Rule 1 is a rule that when the measured dioxin concentration is low, normal combustion is performed, so that the amount of combustion air and the amount of waste are not adjusted. Rule 2 is that when the concentration of dioxins is high and the concentration of oxygen is high or the temperature in the furnace is low, the combustion state is not actively performed due to excess oxygen, so the amount of combustion air supplied to the furnace should be reduced. And / or increase the amount of refuse supplied to restore the combustion state. Rule 3 is that the concentration of dioxins is high and
When the oxygen concentration is low or the furnace temperature is high, the combustion state is not actively performed due to oxygen deficiency. Therefore, the amount of combustion air supplied to the furnace is increased and / or the amount of refuse supplied is reduced. The rule is to restore the combustion state.

Next, as an example of a specific calculation method based on this control rule, a case where a dioxin generation amount and an oxygen concentration are set as measurement amounts, and only a combustion air amount shown in (1) of Table 1 is set as an operation amount. explain.

FIG. 2 is a flow chart illustrating the conditions in Table 1. Starting from START in FIG. 2 and following the flowchart, it is determined at regular intervals whether or not the conditions of S1 and S2 are satisfied, and finally the correction amount W is determined. The correction amount W and the previous value U _{k of the} combustion air amount are determined. The current value U _k of the combustion air amount is derived from ₋₁ .

In FIG. 2, DX represents the concentration of dioxins, and O ₂ represents the concentration of oxygen. DX _H is an adjustment parameter for determining the upper limit determination value of dioxin concentration, O _HL
Is a parameter for determining the level of the O ₂ concentration. G ₁ and G ₂ are adjustment parameters for giving a decrease amount and an increase amount of the combustion air amount, respectively.

Referring to FIG. 2, control of the combustion air amount will be described. In step S1, the condition of DX (dioxin concentration)> DX _H (dioxin concentration upper limit) is determined. If this condition is not satisfied, W is set to 0 according to rule 1 in Table 1. If satisfied, go to step S2. In step S2, O ₂ (oxygen concentration)>
The condition of O _HL (oxygen concentration high / low determination value) is determined. If this condition is satisfied, W is set to G according to rule 2 in Table 1.
Set to ₁ . If not, set W to G ₂ according to rule 3 in Table 1.

As described above, the correction amount W is determined, and the current value U _k of the combustion air amount is derived from the correction amount W and the previous value U _k−1 according to the following equation. U _k = U _k-1 + W As described above, the optimum combustion air amount U _k for suppressing the generation of dioxins in the combustion furnace 11 is obtained.

Next, when the water spray mechanism is provided in the combustion furnace 11, the dioxin concentration and the temperature in the furnace indicate
Table 2 shows an example of a procedure for controlling and adjusting the water spray amount by the calculation unit 13 and a specific calculation method thereof. First, it is sequentially determined whether the current combustion state satisfies the conditions shown in the state quantities in Table 2. If these conditions apply, see Table 2
The control indicated by the operation unit is executed. As a result of the execution of this control, the water spray amount adjusting means 16 is adjusted according to the increment or decrement set in advance for each condition.

[0037]

[Table 2]

Rule 1 is that when the measured dioxin concentration is high and the temperature in the furnace of the combustion furnace is low, the combustion balance is disturbed due to excessive cooling of the furnace by water spray, The rule is to reduce the amount and restore the combustion state. Rule 2 is a rule that when the concentration of dioxins is low but the temperature inside the furnace is high, the combustion state is normal, but the amount of water spray is increased in order to prevent deterioration of the furnace wall due to high temperature.

Next, as an example of a specific calculation method based on these control rules, a case where a dioxin concentration and a furnace temperature are set as measurement amounts and a water spray amount is set as an operation amount will be described.

FIG. 3 is a flow chart of the conditions in Table 2. Starting from START in the figure, it is determined according to a flowchart whether or not each of the conditions S1, S2, and S3 is satisfied at regular intervals, and finally the correction amount Y is determined. The correction amount Y and the previous value R of the water spray amount are determined. The current value R _k of the water spray amount is derived from _k−1 .

In FIG. 3, DX represents the concentration of dioxins, and _Tf represents the furnace temperature. The adjustment parameter DX _H is to determine the upper limit determination value of dioxin concentration, T
_H and _TL are parameters for determining the upper and lower limits of the furnace temperature. H ₁ and H ₂ are adjustment parameters for giving the decrement amount and the increment amount of the water spray amount, respectively.

Referring to FIG. 3, control of the water spray amount will be described. In step S1, the condition of DX (dioxin concentration)> DX _H (dioxin concentration upper limit) is determined. If this condition is satisfied, the process proceeds to step S2; otherwise, the process proceeds to step S3. Step S
In 2, the condition of _Tf (furnace temperature) < _TL (furnace temperature lower limit discrimination value) is determined. If you meet this condition,
The Y according to the rules 1 in Table 2 is set to H _1, the Y to be satisfied is set to 0. In step S3, the condition of _Tf (furnace temperature)> _TH (furnace temperature upper limit determination value) is determined. If this condition is satisfied, Y is set to H ₂ according to rule 2 of Table 2, and if not, Y is set to 0.

As described above, the correction amount Y is determined, and the current value R _k of the water spray amount is derived from the correction amount Y and the previous value R _k−1 according to the following equation. R _k = R _k-1 + Y As a result, an optimal water spray amount R _k for suppressing the generation of dioxins in the combustion furnace 11 is obtained.

In the control method described above, when a real-time automatic analyzer capable of measuring dioxins substantially in real time is used as the dioxins measuring means 12, more appropriate combustion control can be performed. And the effect of reducing dioxins is improved.

Further, the waste incineration method according to the embodiment of the present invention provides a method for producing at least one type of dioxin in the combustion furnace 11 of the waste incineration apparatus 10, the oxygen concentration and / or
Alternatively, the temperature in the furnace is measured, and based on the generated amount data, it is determined whether the amount of waste supplied to the combustion furnace 11 and / or the amount of combustion air supplied to the combustion furnace 11 is excessive or insufficient. The refuse supply amount and / or the combustion air amount are adjusted based on the determination. When the water spray mechanism is provided in the combustion furnace, the amount of water spray can be adjusted.
As a result, the amount of refuse supplied to the combustion furnace 11 and / or the amount of combustion air and the amount of water spray are maintained at appropriate values where the amount of generated dioxins is extremely small. Can be suppressed.

[0046]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given of tests conducted to confirm the effect of reducing dioxins in waste incineration using the waste incinerator of the present invention. FIG. 4 is a schematic view of the vicinity of a combustion chamber of a stoker-type incinerator 50 used in this embodiment.

At the inlet side of the combustion chamber 51, the dust supplied by the dust input hopper 52 is supplied to the grate, and the dust supply pusher 120 and the dust sent by the pusher are sequentially swung to be incinerated. Grate 53 is provided.
The grate 53 has a grate speed controller 53a that can supply debris on the grate at an arbitrary speed. As the supply source of the combustion air, the primary combustion air supply unit 55 and the primary combustion air amount adjuster 55a, and the secondary combustion air supply units 58 and 2
A next combustion air amount regulator 58a is provided. Primary combustion air supply unit 55 and primary combustion air amount regulator 55a
Supplies the primary combustion air onto the grate 53 via a wind box 54 divided into four places in the combustion chamber 51. The secondary combustion air supply unit 58 and the secondary combustion air amount regulator 58a are
Secondary combustion air is supplied to a space region in the combustion chamber 51 divided by the grate 53 and the intermediate ceiling 57.
A boiler 59 is connected to the outlet side of the combustion chamber 51. A gas cooling tower (not shown) and a dust collector (bag filter) (not shown) are sequentially provided downstream of the boiler 59.

The refuse incineration device 50 is provided with a dioxin measurement device 61 for measuring dioxins generated in the combustion chamber 51 and an oxygen concentration (O ₂ ) measurement device 110 for measuring oxygen concentration. The arithmetic unit 62 is electrically connected to the dioxin measuring device 61 and the oxygen concentration measuring device 110, and is configured to transmit their measurement data signals. The dioxin measuring device 6
From 1, the generation amount data of at least one kind of dioxins is transmitted. The arithmetic unit 62 is electrically connected to a grate speed adjuster 53a, which is a means for adjusting the amount of waste, and a secondary combustion air amount adjuster 58a, which is an adjusting means for the amount of combustion air. The control signal can be transmitted.

The refuse incinerator 5 shown in FIG. 4 as described above.
At 0, a signal of 2,8-dichlorodibenzofuran was generated from the dioxin measuring device 61, which is a real-time measuring device, and an oxygen concentration detection signal was generated from the oxygen concentration measuring device 110 at a rate of once every 10 seconds. The arithmetic unit 62 performs an arithmetic operation on these signals in accordance with the arithmetic method according to the control rule shown in Table 1 above, and adjusts the grate speed as an adjustment of the refuse supply amount so as to reduce the amount of dioxins generated. Was burned by adjusting the amount of secondary combustion air as the adjustment of the amount of combustion air. The measured value of the amount of generated dioxins: 2,8-dichlorodibenzofuran measured by the dioxin measuring device 61 which is a real-time measuring device is an integrated value for 10 seconds.

In this example, laser multiphoton ionization mass spectrometry was used as a method for measuring dioxins in real time. The exhaust gas sampling position is at the outlet of the dust collector, and the exhaust gas is drawn at 1 liter / minute by a pump.
On the way, the sample introduction part of the laser multiphoton ionization mass spectrometer was connected. This sample introduction part has a 0.8 mm diameter nozzle, and is composed of a pulse valve and a high vacuum part which open intermittently for 250 μsec at a rate of 50 times per second. When the pulse valve opens, a molecular jet is formed that is cooled to near absolute zero. A dye laser (wavelength: 303.3 n) excited by a yag laser is applied to this molecular jet.
m and laser light of two colors of 210 to 220 nm, each having a laser energy of about 5 mJ), were irradiated for 150 fsec in synchronization with a pulse valve. In the subsequent stage, a time-of-flight mass spectrometer (reflectron type, flight distance of 2000 mm, detector is a microchannel plate) is arranged, and is one of the dioxins ionized under the above conditions. , 8-Dichlorodibenzofuran was detected (counting method), and the obtained data on the amount of generated 2,8-dichlorodibenzofuran was transmitted to the calculation unit 62.

FIG. 5 shows the operation pattern at this time. The fluctuation of oxygen by the oximeter installed downstream of the dust collector is 6.3.
８8.3%. Under this operating condition, 190
Exhaust gas was sampled for 2 hours from a sampling hole on the outlet side of the dust collector operating at ２１０210 ° C. by a method based on the US EPA method. The obtained sample is analyzed by the analysis method generally used for dioxins (based on concentration and cleanup by manual analysis and quantitative determination by high performance gas chromatograph-mass spectrometer) to generate dioxins. The amount was determined. Table 3 shows the results.

COMPARATIVE EXAMPLE In the same refuse incinerator as in the example, a signal was received only from the CO measuring means (not shown) without receiving a signal from the dioxin measuring device 61, and the CO was controlled by a combustion control based on fuzzy control. Combustion was performed by changing the refuse supply speed and the amount of combustion air to reduce the generation. The operation at this time is shown in FIG. The variation of the oxygen concentration was slightly different from that of the example, and was 4.6 to 6.6%. In this state, exhaust gas sampling was performed in the same manner as in the example, and dioxins were quantified. Table 3 shows the results.

[0053]

[Table 3] As is clear from Table 3, the dioxin concentration could be further reduced by the incineration method in the refuse incinerator 50 of the example as compared with the comparative example.

[0054]

As described above, according to the refuse incineration apparatus and method of the present invention, the amount of dioxins generated, the oxygen concentration and / or the furnace temperature are measured, and the amount of dioxins generated is reduced. Performing appropriate combustion control. Thereby, generation of dioxins in the refuse incinerator can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a refuse incinerator according to the present invention.

FIG. 2 is a diagram showing an example of a flowchart of a control method in the refuse incineration method of the present invention.

FIG. 3 is a diagram showing another example of a flowchart of a control method in the refuse incineration method of the present invention.

FIG. 4 is a schematic diagram showing a schematic structure around a combustion chamber of a stalker type waste incinerator used in an embodiment of the present invention.

FIG. 5 shows the concentration of dioxins or CO relative to the oxygen concentration of incineration exhaust gas obtained in Examples and Comparative Examples of the present invention.
FIG. 4 is a characteristic diagram showing a change in density.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Garbage incinerator 11 ... Combustion furnace 12 ... Dioxins measuring means 13 ... Calculation part 14 ... Garbage supply amount adjusting means 15 ... Combustion air amount adjusting means 16 ... Water spray amount adjusting means 101 ... Oxygen concentration measuring means 102 ... Inside furnace Temperature measuring means 50 refuse incinerator 51 combustion chamber 52 refuse charging hopper 53 grate 53 a grate speed regulator 54 wind box 55 primary combustion air supply unit 55 a primary combustion air amount regulator 57 ... Intermediate ceiling 58 ... Secondary combustion air supply unit 58a ... Secondary combustion air amount regulator 59 ... Boiler 61 ... Dioxin measuring device 62 ... Calculation unit 110 ... Oxygen concentration measuring device DX ... Dioxin concentration DX _H ... Dioxin concentration Adjustment parameter for determining the upper limit determination value of O _HL ... Parameter for determining the level of O ₂ concentration W ... Correction amount for combustion air amount G ₁ ... Combustion air The lower limit of the parameter T _L ... furnace temperature to determine the upper limit of the adjustment parameter T _f ... combustion furnace temperature T _H ... furnace temperature to give increments of adjustment parameters G ₂ ... combustion air amount giving a reduced amount of air amount Parameters to be determined Y: Correction amount for water spray amount H ₁ : Adjustment parameter for decrement of water spray amount H ₂ : Adjustment parameter for increment of water spray amount

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Satoshi Fujii 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Manabu Kuroda 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan (56) References JP-A-8-110027 (JP, A) JP-A-9-33026 (JP, A) JP-A-5-99411 (JP, A) JP-A-63-104665 (JP, A) A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F23G 5/50 G01N 27/62

Claims (5)

(57) [Claims] 1. A combustion furnace in which refuse is burned in combustion air, a dioxin measuring means for directly measuring an amount of at least one dioxin generated in the combustion furnace, and an oxygen gas in the combustion furnace. Oxygen measuring means for measuring the concentration, furnace temperature measuring means for measuring the furnace temperature of the combustion furnace , dioxins measuring means, oxygen measuring means, and furnace temperature
Based on data on the amount of at least one type of dioxins, oxygen concentration, and furnace temperature measured by the temperature measuring means, and / or 2
A calculation unit for determining whether the amount of the next combustion air is excessive or deficient and generating a control signal; What is claimed is: 1. A refuse incineration system for suppressing generation of dioxins, comprising: a supply amount adjusting means for adjusting an amount of secondary combustion air, wherein : (a) a concentration of dioxins is high and an oxygen concentration is high.
If it is determined that squid or furnace temperature is low,
Control to increase the amount and / or reduce the amount of secondary combustion air
Generating a control signal, (b) the concentration of dioxins is high and the oxygen concentration is low
If it is determined that squid or furnace temperature is high,
Control to reduce the amount and / or increase the amount of secondary combustion air
A refuse incinerator that suppresses the generation of dioxins, which generates a control signal . 2. A combustion furnace for burning refuse in combustion air therein, a water spraying means for spraying water into the combustion furnace, and directly measuring an amount of at least one type of dioxins generated in the combustion furnace. Dioxins measuring means, furnace temperature measuring means for measuring the furnace temperature of the combustion furnace, and the amount of refuse supplied to the combustion furnace based on the amount of at least one type of dioxins measured by the dioxin measuring means And / or determining whether the amount of secondary combustion air is excessive or deficient, based on the amount of at least one type of dioxins measured by the dioxins measuring means and the furnace temperature data measured by the furnace temperature measuring means, An arithmetic unit that determines whether the amount of water sprayed on the combustion furnace is excessive or insufficient and generates a control signal; and a refuse that reduces the amount of at least one type of dioxins generated in the combustion furnace according to the control signal. A feed amount and / or inhibits waste incinerator generation of secondary combustion air amount and water spray amount and dioxins and a supply amount adjusting means for adjusting, in the arithmetic unit, (a) Dioxins High concentration and low furnace temperature
Control signal to reduce the amount of water spray
Occurs, low (b) the concentration of dioxins, and furnace temperature is high
Control signal to increase the amount of water spray
A refuse incinerator that suppresses the generation of dioxins, which is characterized in that it is generated. 3. The refuse incineration according to claim 1, wherein said dioxin measuring means measures the amount of at least one type of dioxin generated substantially in real time. apparatus. 4. A refuse incineration method for burning refuse in combustion air inside a combustion furnace, comprising: an amount of at least one type of dioxins generated in the combustion furnace; an oxygen concentration in the combustion furnace; Measuring the internal temperature, the amount of at least one type of dioxins, oxygen concentration,
Determining the amount of waste supplied to the combustion furnace and / or the amount of secondary combustion air supplied to the combustion furnace based on the measured data of the furnace temperature and the amount of waste supplied and / or secondary combustion air Based on the determination of the excess or deficiency of the amount, the amount of the waste supplied and / or the amount of the waste is reduced so that the amount of the at least one dioxin generated in the combustion furnace is reduced.
A method for controlling the generation of dioxins, the method comprising: adjusting the amount of secondary combustion air, wherein the determination step (a) comprises : (a) a high concentration of dioxins and a high oxygen concentration;
If it is determined that squid or furnace temperature is low,
Insufficient amount and / or excessive amount of secondary combustion air
Judgment, high concentration of (b) dioxins, and oxygen concentration is low
If it is determined that squid or furnace temperature is high,
If the amount is excessive and / or the amount of secondary combustion air is insufficient
A refuse incineration method for suppressing the generation of dioxins, characterized by determining . 5. A refuse incineration method for burning refuse in combustion air inside a combustion furnace, comprising: measuring an amount of at least one type of dioxins generated in the combustion furnace and a temperature in the furnace; Based on the measurement data of the amount of generation of at least one dioxin, it is determined whether the amount of refuse supplied to the combustion furnace and / or the amount of secondary combustion air supplied to the combustion furnace is excessive or insufficient. Determining the excess or deficiency of the water spray amount to the combustion furnace based on the measurement data of the generated amount and the furnace temperature; and performing the combustion based on the determination of the excess or deficiency of the waste supply amount and / or the secondary combustion air amount. In order to reduce the amount of at least one dioxin generated in the furnace, the amount of waste supplied and / or
Or adjusting the amount of secondary combustion air, and adjusting the amount of water spray such that the amount of at least one type of dioxins generated in the combustion furnace is reduced based on the determination of excess or deficiency of the amount of water spray. A refuse incineration method for suppressing generation of dioxins provided, wherein in the determining step , (a) the concentration of dioxins is high and the furnace temperature is low.
If it is determined that the water spray amount is excessive , (b) the dioxin concentration is low and the furnace temperature is high.
A waste incineration method for suppressing the generation of dioxins, wherein it is determined that the amount of water spray is insufficient when it is determined that the water spray amount is insufficient .