JP2002181320A - Waste gasification combustion system and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a waste gasification combustion system from generating or discharging toxic substances, such as CO, DXN, NOx and the like, even if there is fluctuations in the feeding amount or calorie of waste, by making the feeding amount of waste or a combustion improver controllable, in response thereto to keep a furnace load constant in the melting furnace and the like for complete combustion. SOLUTION: The waste gasification combustion system comprises a thermal decomposition furnace for pyrolizing waste, a melting furnace for melting ashes and the like by the thermally decomposed gas and a secondary combustion chamber provided downstream from the melting furnace. It further comprises a waste-feeding amount adjustor for adjusting the feeding amount of waste, of CO concentration detector for detecting the CO concentration in a gas channel, and a controller for comparing the detected CO concentration in the gas channel with the tolerance thereof and outputting an adjusting signal for the feeding amount of waste, based on the compared results such that the CO concentration in the gas channel becomes smaller than the tolerance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pyrolysis gas generated by pyrolyzing waste in a pyrolysis furnace, and introducing the pyrolysis gas into a melting furnace to melt solids such as ash in the melting furnace. The present invention relates to a waste gasification combustion apparatus and a combustion method in which a gas delivered from the melting furnace is burned in a secondary combustion chamber.

[0002]

2. Description of the Related Art A pyrolysis furnace for thermally decomposing waste to generate a pyrolysis gas, a melting furnace for melting solids such as ash with the pyrolysis gas, and burning gas sent from the melting furnace In the waste gasification and combustion system provided with a secondary combustion chamber for allowing the solidification material to have a melting temperature of 135 in the melting furnace.
Since a high temperature of 0 ° C. to 1500 ° C. is required, air (primary air) and an auxiliary fuel are supplied to the melting furnace in addition to the pyrolysis gas, so that the solid can be melted at the high temperature.

In such a waste gasification combustion system, Japanese Patent Application Laid-Open No. H11-351538 has been proposed as one means for controlling the amount of primary air to an ash melting furnace to an appropriate amount. In this invention, the temperature in the ash melting furnace and the temperature in the secondary combustion chamber are detected, and the detected temperature is compared with a reference temperature (appropriate temperature) to estimate the excess or deficiency of the primary air flow to the ash melting furnace. Then, the primary air supply amount is controlled to the target value by operating the flow control valve.

[0004]

In such a waste gasification and combustion system, if the calories (owned heat) of the waste supplied to the pyrolysis furnace become low, the amount of waste supplied is reduced. And the amount of the auxiliary agent supplied to the ash melting furnace is increased, and the temperature in the ash melting furnace is maintained at 1350 ° C. or more to perform stable ash melting. However, if the amount of pyrolysis gas generated in the pyrolysis furnace increases due to fluctuations in the quality of waste and the calories increase, incomplete combustion occurs in the ash melting furnace. The temperature in the ash melting furnace may be lower than the ash melting temperature (about 1350 ° C.).

However, usually, the amount of waste supplied to the pyrolysis furnace and the amount of auxiliary agent supplied to the ash melting furnace are detected by detecting the temperature in the ash melting furnace or the temperature in the secondary combustion chamber. Adjusted based on values. For this reason, when the incomplete combustion as described above occurs and the temperature in the ash melting furnace or the temperature in the secondary combustion chamber decreases, the supply amount of the waste and the supply amount of the auxiliary agent increase. As a result, even if the load in the furnace in the ash melting furnace increases and the amount of combustion air increases, complete combustion is not performed by the outlet of the secondary combustion chamber, and CO (carbon monoxide), DXN (dioxin), NOx (nitrogen) Oxides) and other harmful substances are a major factor.

In the invention of Japanese Patent Application Laid-Open No. 11-351538, the temperature in the ash melting furnace and the temperature in the secondary combustion chamber are detected, and the amount of primary air supplied to the ash melting furnace is controlled to a target value. However, the control of the supply amount of waste or the supply amount of the auxiliary agent by the temperature is not performed. That is, in the invention, only the air supply amount to the ash melting furnace is controlled by the temperature in the ash melting furnace and the temperature in the secondary combustion chamber, and the control of the waste supply amount or the auxiliary agent supply amount by the temperature is performed. As described above, when the amount of generated pyrolysis gas generated in the pyrolysis furnace increases due to fluctuations in the quality of the waste as described above, the waste It is impossible to control the supply amount or the auxiliary agent supply amount, and C
O (carbon monoxide), DXN (dioxin), NOx
Hazardous substances such as (nitrogen oxides) are seen in large quantities.

The present invention has been made in view of the above-mentioned problems in the prior art, and in a waste gasification and combustion system, even if there is a fluctuation in the amount of supplied waste or calories, the amount of supplied waste or the amount of supplied auxiliary fuel follows the fluctuation. And complete combustion with constant furnace load in a melting furnace, etc.
An object is to prevent generation and emission of harmful substances such as XN and NOx.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides, as an invention according to claim 1, a pyrolysis furnace which pyrolyzes waste to generate a pyrolysis gas; A waste supply device for supplying the waste, a melting furnace for melting solids such as ash by a pyrolysis gas sent from the pyrolysis furnace through a pyrolysis gas pipe, and a gas sent from the melting furnace. And a secondary combustion chamber that burns unburned matter and discharges it to an exhaust gas pipe, and controls the amount of waste supplied to the pyrolysis furnace of the waste supply apparatus. And a CO concentration detector for detecting a CO (carbon monoxide) concentration in a gas passage between a pyrolysis gas pipe and an exhaust gas pipe including the melting furnace and the secondary combustion chamber. Detecting the CO concentration in the gas passage from the CO concentration detector And a permissible value (threshold) of the CO concentration in the gas passage, and based on the comparison result, a metering signal of the waste supply amount such that the CO concentration in the gas passage becomes equal to or less than the permissible value. A waste gasification combustion device comprising a controller for outputting to a waste supply amount adjusting device is proposed.

In claim 1, preferably, claim 2
Wherein the CO concentration detector is a pyrolysis gas CO concentration detector for detecting the CO concentration in the pyrolysis gas line, or the CO concentration detector is a CO The ash melting furnace is a CO concentration detector for detecting the concentration, or as in claim 4, the CO concentration detector is a CO concentration detector for detecting the CO concentration in the secondary combustion chamber. Constitute.

According to a fifth aspect of the present invention, in addition to the first aspect, the temperature of the gas in the gas passage between the pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and the exhaust gas pipe is detected. A gas temperature detector, a gas temperature detected value in the gas passage from the gas temperature detector is compared with a reference value of the gas temperature at the detection site, and the gas temperature in the gas passage is determined based on the comparison result. A controller for outputting a measurement signal of the amount of waste supplied so as to be the reference value to the waste supply amount adjusting device.

According to a fifth aspect of the present invention, the apparatus is preferably configured as in the sixth or seventh aspect. That is, in claim 6, the gas temperature detector is a melting furnace temperature detector for detecting the temperature in the melting furnace, the controller is a melting furnace temperature detection value and a reference value of the temperature in the melting furnace. And a signal for metering the amount of waste supplied such that the temperature in the melting furnace becomes the reference value based on the comparison result is output to the waste supply adjusting device.
According to claim 7, the gas temperature detector is a secondary combustion chamber temperature detector for detecting a temperature in the secondary combustion chamber, and the controller is configured to detect the temperature of the secondary combustion chamber and the temperature in the secondary combustion chamber. And outputting a waste supply amount adjustment signal to the waste supply amount adjusting device such that the temperature in the secondary combustion chamber becomes the reference value based on the comparison result. I do.

According to an eighth aspect of the present invention, in addition to the first aspect, an auxiliary combustion device for supplying an auxiliary combustion agent to the melting furnace, and an auxiliary combustion amount adjustment for adjusting a supply amount of the auxiliary combustion agent to the melting furnace by the auxiliary combustion device. Device, the controller compares the detected value of the CO concentration in the gas passage from the CO concentration detector with an allowable value of the CO concentration in the gas passage, and based on the comparison result, the controller in the gas passage. It also has a function of outputting a metering signal of the amount of the auxiliary combustion agent supplied so that the CO concentration becomes equal to or less than the allowable value to the auxiliary combustion amount adjusting device.

According to a ninth aspect of the present invention, in addition to the eighth aspect, the temperature of the gas in the gas passage between the pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and the exhaust gas pipe is detected. A controller that compares a gas temperature detection value in the gas passage from the gas temperature detector with a reference value of gas temperature at the detection portion, and based on the comparison result, It also has a function of outputting a metering signal of the amount of the auxiliary combustion agent supplied so that the gas temperature in the passage becomes the reference value to the auxiliary combustion amount adjusting device.

[0014] The invention according to claims 10 to 13 is an invention using the apparatus according to claims 1 to 9, and the invention according to claim 10 is a method in which waste supplied by a waste supply device is supplied to a pyrolysis furnace. Pyrolysis gas to generate a pyrolysis gas, and melt a solid such as ash in a melting furnace in which the pyrolysis gas is fed from the pyrolysis furnace through a pyrolysis gas pipe, and in a secondary combustion chamber. In the gasification and combustion method of the waste which burns the gas and the unburned matter discharged from the melting furnace and discharges the waste gas into an exhaust gas pipe, the method includes the steps of: a pyrolysis gas pipe including the melting furnace and a secondary combustion chamber; A CO (carbon monoxide) concentration in a gas passage between the gas passages, and a detected value of the CO concentration is compared with a permissible value (threshold) of the CO concentration in the gas passage. So that the concentration of CO in the product is less than the allowable value Wherein the metering waste feed to the pyrolysis furnace.

According to an eleventh aspect of the present invention, in addition to the tenth aspect, the temperature of the gas in the gas passage between the pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and the exhaust gas pipe is detected. Comparing the detected value of the gas temperature with a reference value of the gas temperature at the detection site, and metering a waste supply amount based on the comparison result such that the gas temperature in the gas passage becomes the reference value. It is characterized by.

According to a twelfth aspect of the present invention, in addition to the tenth aspect, there is provided a combustion assisting device for supplying a combustion assisting agent to the melting furnace, further comprising a combustion assisting amount adjusting device for measuring a supply amount of the combustion assisting agent to the melting furnace,
The detected value of the CO concentration is compared with a permissible value of the CO concentration in the gas passage. Based on the result of the comparison, the combustion assisting agent adjusts the amount of the combustion aid such that the CO concentration in the gas passage becomes the permissible value or less. It is characterized in that the supply amount is adjusted.

According to a thirteenth aspect of the present invention, in addition to the twelfth aspect, the temperature of the gas in the gas passage between the pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and the exhaust gas pipe is detected. Comparing the detected value of the gas temperature with the reference value of the gas temperature at the detection site, and adjusting the amount of the auxiliary agent supplied so that the gas temperature in the gas passage becomes the reference value based on the comparison result. It is characterized by performing.

According to the invention, when the detected value of the CO concentration is larger than the permissible value (threshold) of the CO concentration by the controller, the waste supply device switches to the pyrolysis furnace, and the pyrolysis furnace changes to the melting furnace. 10. The waste is supplied at a supply amount that keeps the CO concentration in the gas flow path leading to the secondary combustion chamber through the above process at or below the allowable value (threshold).
In the inventions described in 12, 13 and 13, the auxiliary agent can be supplied from the auxiliary device to the melting furnace at a supply amount that keeps the CO concentration in the gas flow path at or below the allowable value (threshold value). .

Therefore, even when the amount of pyrolysis gas generated in the pyrolysis furnace increases due to fluctuations in the quality of the waste and the calories increase, the pyrolysis furnace according to the prior art can be used. That controls the amount of waste supplied to the furnace and the amount of auxiliary agent supplied to the ash melting furnace by the temperature in the melting furnace or the secondary combustion chamber, or the air supply to the melting furnace by the temperature in the melting furnace and the secondary combustion chamber The occurrence of incomplete combustion due to an increase in the furnace load, such as that controlling the amount, is avoided, the furnace load in the melting furnace is maintained at an appropriate value, and the combustion process to the outlet of the secondary combustion chamber is completely completed. Combustion can be achieved, and generation and emission of harmful substances such as CO, DXN, and NOx can be prevented.

When the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration by the controller, it is determined that incomplete combustion has not occurred in the waste treatment system. According to the inventions described in (11) and (11), the temperature of the melting furnace or the secondary combustion chamber is controlled, and the amount of the waste supplied from the waste supply device to the pyrolysis furnace is controlled by the melting furnace temperature or the secondary combustion chamber temperature. Claims 8, 9 and 12,
In the invention described in 13, the amount of the auxiliary agent supplied from the auxiliary combustion device to the melting furnace is controlled so that the melting furnace temperature or the secondary combustion chamber temperature becomes the target temperature, so that the furnace load in the melting furnace is adjusted to an appropriate value. And complete combustion can be maintained in the combustion process up to the outlet of the secondary combustion chamber.
Generation and emission of harmful substances such as XN and NOx can be prevented.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to an embodiment shown in the drawings. However, unless otherwise specified, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. It's just

FIG. 1 is an overall configuration diagram of a waste gasification combustion apparatus according to an embodiment of the present invention, FIG. 2 is a control block diagram, and FIG.
Is a control flowchart. In FIG. 1, reference numeral 02 denotes a hopper for charging waste (garbage) 3, and reference numeral 2 denotes a waste supply device including a screw feeder for supplying the waste 3 to a pyrolysis furnace 1 described later. Reference numeral 1 denotes a pyrolysis furnace that pyrolyzes waste 3 supplied from the waste supply device 2 to generate a pyrolysis gas, and includes a lower fluidized sand layer 1a and an upper free board 1b. Reference numeral 5 denotes an ash melting furnace for melting solids such as solid ash, fly ash, and char by the pyrolysis gas.

Reference numeral 6 denotes a secondary combustion chamber which is connected to the upper part of the melting furnace 5 and burns gas from the melting furnace 5 and unburned contaminants in the gas. Is formed. Reference numeral 4 denotes a pyrolysis gas pipe for transporting the pyrolysis gas generated in the pyrolysis furnace 1 to the ash melting furnace 5. Reference numeral 12 denotes a combustion assisting device for supplying a combustion assisting agent to the ash melting furnace 5. Reference numeral 8 denotes an exhaust gas pipe connected to the exhaust gas outlet of the secondary combustion chamber 6, reference numeral 9 denotes an exhaust gas treatment device provided in the exhaust gas pipe 8 for purifying exhaust gas, and reference numeral 10 denotes a chimney. The above configuration is the same as in the related art. In the present invention, the following improvements are made.

That is, in FIG. 1, reference numeral 14 denotes a waste supply amount adjusting device for measuring the amount of waste supplied to the pyrolysis furnace 1 of the waste supply device 2. Reference numeral 13 denotes an auxiliary combustion amount adjusting device for adjusting the amount of auxiliary agent supplied to the ash melting furnace 5 of the auxiliary combustion device 12. 15 is a pyrolysis gas CO concentration detector for detecting the CO concentration in the pipeline of the pyrolysis gas pipe 4;
Reference numeral 16 denotes a secondary combustion chamber CO concentration detector for detecting the CO concentration in the secondary combustion chamber 6, and reference numeral 30 denotes an exhaust gas pipe CO concentration detector for detecting the CO concentration in the pipe of the exhaust gas pipe 8. Reference numeral 17 denotes an ash melting furnace temperature detector for detecting a temperature in the ash melting furnace 5, and reference numeral 18 denotes a secondary combustion chamber temperature detector for detecting a temperature in the secondary combustion chamber 6.

Reference numeral 11 denotes a controller,
O concentration detector 15, ash melting furnace CO concentration detector 16, CO concentration detection value in the gas passage from the secondary combustion chamber CO concentration detector 30, and the ash melting furnace from the ash melting furnace temperature detector 17. 5 and a detected value of the temperature in the secondary combustion chamber 6 from the secondary combustion chamber temperature detector, respectively, and a metering signal of the waste supply amount calculated based on these detection signals. The waste supply amount adjusting device 14
At the same time, the metering signal of the amount of the auxiliary fuel supplied is sent to the auxiliary fuel adjusting device 13.
, Respectively, the details of which will be described later.

During the operation of the waste gasification and combustion system having the above-mentioned configuration, the waste (garbage) 3 is removed from the fluidized sand layer 1a of the pyrolysis furnace 1 by the waste supply device 2.
Supplied to In the pyrolysis furnace 1, the waste 3 supplied from the waste supply device 2 is thermally decomposed while maintaining the temperature of the waste 3 at a high temperature by a high-temperature fluidized sand introduced from a fluidized sand circulating means (not shown). To produce char from which hot pyrolysis gases and chlorine have been removed.

The pyrolysis gas having passed through the free board 1b of the pyrolysis furnace 1 is sent to an ash melting furnace 5 through a pyrolysis gas pipe 4. In the ash melting furnace 5, solids such as solid ash, char, fly ash and the like are melted at a high temperature of 1350 ° C. or more by the pyrolysis gas. At the time of pyrolysis in the pyrolysis furnace 1 and combustion in the ash melting furnace 5 and melting of the solid,
As will be described later, the controller controls the amount of the waste supplied or the amount of the auxiliary agent supplied, and completes the combustion in the ash melting furnace 5 with a constant furnace load. The gas from the ash melting furnace 5 is subjected to secondary combustion together with the char mixed in the gas in the secondary combustion chamber 6, purified through an exhaust gas pipe 8 in an exhaust gas treatment device 9, and
Emitted from 0 to the atmosphere.

Next, the control of the supply amount of the waste and the supply amount of the auxiliary agent by the controller 11 will be described with reference to FIGS. 2 and 3.
The CO concentration in the pipeline of the pyrolysis gas pipe 4 detected at is input to the pyrolysis gas CO concentration comparator 22 of the controller 11. 21 is a reference CO concentration setting device,
From 0, an allowable value (threshold) of the CO concentration in the exhaust gas discharged into the atmosphere is set. In the pyrolysis gas CO concentration comparator 22, the pyrolysis gas CO concentration detector 1
5 is compared with the set value (permissible value) of the CO concentration, the deviation is calculated, and sent to the waste supply amount calculator 28 and the auxiliary agent supply amount calculator 29 (FIG. Step 3 (1)).

The CO concentration in the ash melting furnace 5 detected by the ash melting furnace CO concentration detector 16 is input to an ash melting side CO concentration comparator 23 of the controller 11. Further, the CO concentration in the secondary combustion chamber 6 detected by the CO concentration detector 30 in the secondary combustion chamber is also determined by the controller 1.
1 is input to the ash melting side CO concentration comparator 23. In the ash melting side CO concentration comparator 23, the detected value of the CO concentration from the ash melting furnace CO concentration detector 16 and the CO concentration detector 30 in the secondary combustion chamber and the set value of the CO concentration (permissible value) ) Is calculated, and the deviation is calculated, and the deviation larger than the set value is sent to the waste supply amount calculator 28 and the auxiliary agent supply amount calculator 29.

The temperature in the ash melting furnace 5 detected by the ash melting furnace temperature detector 17 is input to an ash melting furnace temperature comparator 25 of the controller 11. Reference numeral 24 denotes an ash melting furnace temperature setter, which is a target temperature (for example, 1350 ° C.) at which the ash melting action in the ash melting furnace 5 can be achieved by complete combustion.
Is set. And the ash melting furnace temperature comparator 25
In the above, the detected value of the ash melting furnace temperature from the ash melting furnace temperature detector 17 is compared with the target temperature set in the ash melting furnace temperature setting device 24, and the deviation is calculated to calculate the deviation. It is sent to the supply amount calculator 28 and the auxiliary agent supply amount calculator 29.

The temperature in the secondary combustion chamber 6 detected by the secondary combustion chamber temperature detector 18 is input to a secondary combustion chamber temperature comparator 27 of the controller 11. 26
Is a secondary combustion chamber temperature setter, which sets a target temperature at which complete combustion can be performed in the secondary combustion chamber 6. In the secondary combustion chamber temperature comparator 27, the detected value of the secondary combustion chamber temperature from the secondary combustion chamber temperature detector 18 and the target temperature set in the secondary combustion chamber temperature setter 26 are calculated. Compare and calculate the deviation to obtain the waste supply amount calculator 2
8 and the auxiliary fuel supply amount calculator 29 (steps (2), (3), and (4) in FIG. 3).

In the waste supply amount calculator 28,
Either the pyrolysis gas side CO concentration deviation calculated by the pyrolysis gas CO concentration comparator 22 or the secondary combustion chamber side CO concentration deviation calculated by the secondary combustion chamber side CO concentration comparator 23 is positive (+ That is, the detected value of the CO concentration is equal to the C value.
When the O concentration is larger than an allowable value (threshold), the amount of adjustment of the waste supply amount corresponding to the larger deviation of the pyrolysis gas side CO concentration deviation or the secondary combustion chamber side CO concentration deviation is obtained, Using the adjusted amount, the amount of waste supplied is calculated to increase or decrease the amount of waste supplied from the current state and maintain the CO concentration at or below the allowable value (threshold) (steps (5) and (6) in FIG. 3). )).

In the combustion aid supply amount calculator 29, the pyrolysis gas side CO concentration deviation calculated by the pyrolysis gas CO concentration comparator 22 and the ash calculated by the ash melting side CO concentration comparator 23 are calculated. Any of the melting-side CO concentration deviations is positive (+), that is, the detected value of the CO concentration is
When the concentration is larger than the allowable value (threshold), the adjustment amount of the auxiliary combustion agent supply amount corresponding to the larger deviation of the pyrolysis gas side CO concentration deviation or the ash melting side CO concentration deviation is obtained.
The adjusted amount is used to increase or decrease the current amount of the supplied auxiliary agent to reduce CO2.
Calculate the supply amount of the auxiliary combustion agent required to maintain the concentration at or below the allowable value (threshold) (step (8) in FIG. 3).
(9) (10)).

The calculation signal of the waste supply amount calculated by the waste supply amount calculator 28 is sent to the waste supply amount adjustment device 14, and the waste supply amount adjustment device 14 2. The amount of waste supplied to the pyrolysis furnace 1 is adjusted to the amount of waste supplied as calculated above. That is, when the CO concentration exceeds the allowable value (threshold value), the supply amount of the waste 3 supplied from the waste supply device 2 to the pyrolysis furnace 1 is reduced, so that the furnace load in the ash melting furnace 5 is reduced. To an appropriate value.

Further, a signal for calculating the amount of auxiliary fuel supplied by the auxiliary fuel supply amount calculator 29 is sent to the auxiliary fuel supply amount adjusting device 13. The supply amount of the auxiliary agent to the ash melting furnace 5 is adjusted to the auxiliary agent supply amount calculated as described above. That is,
When the CO concentration exceeds the allowable value (threshold),
The furnace load in the ash melting furnace 5 is reduced to an appropriate value by reducing the amount of the auxiliary agent supplied from the auxiliary combustion device 12 to the ash melting furnace 5 (steps (11) and (12) in FIG. 3).
(13)).

With the above control and operation, the waste supply device 2 sends the heat from the pyrolysis furnace 1 to the ash melting furnace 5 and the secondary combustion chamber 6.
The waste 3 is supplied at a supply amount that keeps the CO concentration at or below the allowable value (threshold) or less, or the ash melting furnace 5 and the secondary combustion chamber 6 The auxiliary agent can be supplied at a supply amount that keeps the CO concentration at or below the allowable value (threshold value) or less, whereby the furnace load in the ash melting furnace 5 is maintained at an appropriate value and the secondary combustion chamber Complete combustion can be achieved in the combustion process up to outlet 6, CO, DXN, NOx
And the generation and emission of harmful substances such as harmful substances.

On the other hand, in the waste supply amount calculator 28, the thermal decomposition gas side CO concentration deviation calculated by the pyrolysis gas CO concentration comparator 22 and the ash melting side CO concentration comparator 23 are calculated. If both of the ash melting side CO concentration deviations are negative (-), that is, the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration, incomplete combustion has occurred in the waste treatment system. If there is no such control, the ash melting furnace temperature control or the secondary combustion chamber temperature control is performed. That is, in the waste supply amount calculator 28, the waste corresponding to the deviation from the target temperature from the ash melting furnace temperature comparator 25 or the deviation from the target temperature from the secondary combustion chamber temperature comparator 27. The amount of waste supplied is determined, and the amount of waste supplied such that the ash melting furnace temperature or the secondary combustion chamber temperature becomes the target temperature is increased or decreased from the current amount of waste supplied using the adjusted amount. calculate.

The waste supply amount calculation signal calculated by the waste supply amount calculator 28 is sent to the waste supply amount adjustment device 14, and the waste supply amount adjustment device 14 is connected to the waste supply device. 2. The amount of waste supplied to the pyrolysis furnace 1 is adjusted to the amount of waste supplied as calculated above. That is, when the temperature of the ash melting furnace or the temperature of the secondary combustion chamber exceeds the target temperature, the waste supply device 2 sends the pyrolysis furnace 1
The ash melting furnace temperature or the secondary combustion chamber temperature is reduced to a target temperature by reducing the supply amount of the waste 3 supplied to the ash melting furnace 5, and the furnace load in the ash melting furnace 5 is reduced to an appropriate value (see FIG. 3). Steps (5) and (6)).

When the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration, the auxiliary combustion agent supply amount calculator 29 calculates the difference between the detected value and the target temperature from the ash melting furnace temperature comparator 25. A deviation, or an adjustment amount of the auxiliary combustion agent supply amount corresponding to the deviation from the target temperature from the secondary combustion chamber temperature comparator 27 is obtained, and the adjustment amount is increased or decreased from the current auxiliary combustion agent supply amount using the adjustment amount. Then, the amount of the auxiliary agent supplied such that the ash melting furnace temperature or the secondary combustion chamber temperature becomes the target temperature is calculated. The calculation signal of the auxiliary fuel supply amount calculated by the auxiliary fuel supply amount calculator 29 is transmitted to the auxiliary fuel supply amount adjusting device 13.
The auxiliary combustion agent supply amount adjusting device 13 adjusts the auxiliary combustion agent supply amount to the ash melting furnace 5 of the auxiliary combustion device 12 to the auxiliary combustion agent supply amount calculated as described above. That is, when the ash melting furnace temperature or the secondary combustion chamber temperature exceeds the target temperature, the ash melting furnace temperature or the secondary combustion chamber temperature is reduced by reducing the supply amount of the auxiliary agent supplied from the auxiliary combustion device 12 to the ash melting furnace 5. The temperature of the secondary combustion chamber is lowered, and the furnace load in the ash melting furnace 5 is reduced to an appropriate value (step (11) in FIG. 3).
(12) (13)).

If the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration by the control and the operation, the supply amount of the waste from the waste supply device 2 is changed to the ash melting furnace temperature Alternatively, controlling the secondary combustion chamber temperature to be the target temperature, or controlling the supply amount of the auxiliary agent from the auxiliary combustion device 12 so that the ash melting furnace temperature or the secondary combustion chamber temperature is the target temperature. Thereby, the furnace load in the ash melting furnace 5 can be maintained at an appropriate value, and complete combustion can be performed in the combustion process up to the outlet of the secondary combustion chamber 6.
Generation and emission of harmful substances such as CO, DXN and NOx can be prevented.

When the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration, the control of the amount of waste supplied from the waste supply device 2 by the waste supply amount adjusting device 14 is performed. When the temperature of the ash melting furnace 5 can be maintained at a high temperature at which a solid such as ash can be melted, the supply of the auxiliary agent from the auxiliary device 12 can be stopped.

[0042]

As described above, according to the present invention, when the detected value of the CO concentration is larger than the allowable value (threshold) of the CO concentration by the controller, the waste supply device sends the CO to the pyrolysis furnace. Waste is supplied in a supply amount such that a CO concentration in a gas flow path from a pyrolysis furnace through a melting furnace to a secondary combustion chamber is maintained at or below the allowable value (threshold). As in the inventions described in the paragraphs 12 and 13, the auxiliary agent can be supplied from the auxiliary combustion device to the melting furnace at a supply amount that keeps the CO concentration in the gas flow path at or below the allowable value (threshold). Thereby, the in-furnace load in the melting furnace can be maintained at an appropriate value, and complete combustion can be achieved in the combustion process up to the secondary combustion chamber outlet,
Generation and emission of harmful substances such as CO, DXN and NOx can be prevented.

If the detected value of the CO concentration is equal to or less than the allowable value (threshold) of the CO concentration by the controller, it is determined that incomplete combustion has not occurred in the waste treatment system. According to the inventions described in 7 and 11, the temperature of the melting furnace or the secondary combustion chamber is controlled, and the supply amount of the waste from the waste supply device to the pyrolysis furnace is determined by the melting furnace temperature or the secondary combustion chamber temperature. Is controlled so as to reach the target temperature. Further, as in the inventions according to claims 8, 9 and 12, and 13, the amount of the auxiliary agent supplied from the auxiliary combustion device to the melting furnace is adjusted to the melting furnace temperature or the secondary combustion chamber temperature. Is controlled to reach the target temperature, the furnace load in the melting furnace can be maintained at an appropriate value, and complete combustion can be maintained in the combustion process up to the outlet of the secondary combustion chamber.
Generation and emission of harmful substances such as O, DXN and NOx can be prevented.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a waste gasification combustion apparatus according to an embodiment of the present invention.

FIG. 2 is a control block diagram of the waste gasification combustion apparatus.

FIG. 3 is a control flowchart of the waste gasification combustion apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pyrolysis furnace 2 Waste supply apparatus 3 Waste 4 Pyrolysis gas pipe 5 Ash melting furnace 6 Secondary combustion chamber 8 Exhaust gas pipe 9 Exhaust gas treatment apparatus 11 Controller 12 Auxiliary combustion apparatus 13 Auxiliary combustion quantity adjustment apparatus 14 Waste supply quantity adjustment apparatus 15 Pyrolysis gas CO concentration detector 16 Ash melting furnace CO concentration detector 17 Ash melting furnace temperature detector 18 Secondary combustion chamber temperature detector 21 Standard CO concentration setting device 22 Pyrolysis gas CO concentration comparator 23 Ash melting side CO Concentration comparator 24 Ash melting furnace temperature setting device 25 Ash melting furnace temperature comparator 26 Secondary combustion chamber temperature setting device 27 Secondary combustion chamber temperature comparator 28 Waste supply amount calculator 29 Fuel burner supply amount calculator 30 Secondary CO concentration detector in combustion chamber

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B09B 3/00 F23G 5/027 ZABB F23G 5/027 ZAB 5/16 ZABB 5/16 ZAB F23J 1/00 B F23J 1/00 B09B 3/00 303 L (72) Inventor Jun Sato, Nishiki-cho, Naka-ku, Yokohama-shi F-term (reference) 3K061 AA11 AA24 AB02 AB03 AC01 AC19 BA06 CA01 EA01 NB03 NB30 3K062 AA11 AA24 AB02 AB03 AC01 AC19 BA02 CB03 CB06 CB08 DA02 DA23 DB01 DB12 3K078 AA06 BA03 BA22 CA03 CA24 4D004 AA01 AA36 CA27 CA29 CB04 CB32 CB34 DA01 DA02 DA06 DA 10 DA12

Claims (13)

[Claims] 1. A pyrolysis furnace that pyrolyzes waste to generate a pyrolysis gas, a waste supply device that supplies the waste to the pyrolysis furnace, and a pyrolysis gas pipe from the pyrolysis furnace. Disposal equipped with a melting furnace that melts solids such as ash by the supplied pyrolysis gas, and a secondary combustion chamber that burns the gas and unburned matter sent from the melting furnace and discharges it to an exhaust gas pipe In a gasification and combustion apparatus for waste, a waste supply amount adjusting device for measuring an amount of waste supplied to the pyrolysis furnace of the waste supply device, and a pyrolysis gas including the inside of the melting furnace and the secondary combustion chamber A CO concentration detector for detecting a CO (carbon monoxide) concentration in a gas passage between the pipe and the exhaust gas pipe; a CO concentration detection value in the gas passage from the CO concentration detector; Compare with the allowable value (threshold) of CO concentration, and A controller for outputting a waste supply amount adjustment signal to the waste supply amount adjustment device such that the CO concentration in the gas passage becomes equal to or less than the allowable value based on the waste gas. Combustion equipment. 2. The waste gasification combustion apparatus according to claim 1, wherein the CO concentration detector is a pyrolysis gas CO concentration detector for detecting a CO concentration in the pyrolysis gas pipeline. 3. The waste gasification and combustion apparatus according to claim 1, wherein said CO concentration detector is an ash melting furnace CO concentration detector for detecting a CO concentration in an ash melting furnace. 4. The waste gasification combustion apparatus according to claim 1, wherein said CO concentration detector is a CO concentration detector for detecting a CO concentration in a secondary combustion chamber. 5. A gas temperature detector for detecting a temperature of a gas in a gas passage between a pyrolysis gas pipe including an inside of the melting furnace and a secondary combustion chamber and an exhaust gas pipe, and The detected value of the gas temperature in the gas passage is compared with a reference value of the gas temperature at the detection site, and the amount of waste supplied is adjusted based on the comparison result such that the gas temperature in the gas passage becomes the reference value. The waste gasification and combustion apparatus according to claim 1, further comprising a controller that outputs an amount signal to the waste supply amount adjustment device. 6. A melting furnace temperature detector for detecting a temperature in the melting furnace, wherein the controller compares the detected temperature in the melting furnace with a reference value of the temperature in the melting furnace. And based on the comparison result, it is configured to output a waste supply amount adjustment signal such that the temperature in the melting furnace becomes the reference value to the waste supply amount adjustment device. The waste gasification combustion apparatus according to claim 5. 7. The secondary combustion chamber temperature detector, wherein the gas temperature detector detects a temperature in the secondary combustion chamber,
The controller compares the detected temperature of the secondary combustion chamber with a reference value of the temperature in the secondary combustion chamber, and based on a result of the comparison, supplies the waste material such that the temperature in the secondary combustion chamber becomes the reference value. The waste gasification and combustion apparatus according to claim 5, wherein the metering signal is output to the waste supply amount adjustment apparatus. 8. An auxiliary combustion device for supplying an auxiliary combustion agent to the melting furnace, and an auxiliary combustion amount adjusting device for adjusting an amount of the auxiliary combustion agent supplied to the melting furnace by the auxiliary combustion device;
Comparing the detected value of the CO concentration in the gas passage from the O concentration detector with an allowable value of the CO concentration in the gas passage,
The apparatus according to claim 1, further comprising a function of outputting a control signal of the amount of supplied auxiliary fuel to the auxiliary fuel amount adjusting device such that the CO concentration in the gas passage becomes equal to or less than the allowable value based on the comparison result. A waste gasification combustion apparatus according to claim 1. 9. A gas temperature detector for detecting a temperature of a gas in a gas passage between a pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and an exhaust gas pipe, and the controller includes: A detected value of the gas temperature in the gas passage from the temperature detector is compared with a reference value of the gas temperature at the detection portion, and based on the result of the comparison, it is determined that the gas temperature in the gas passage becomes the reference value. The waste gasification combustion apparatus according to claim 8, further comprising a function of outputting a fuel supply amount adjustment signal to the auxiliary combustion amount adjustment device. 10. A waste supplied by a waste supply device is thermally decomposed in a pyrolysis furnace to generate a pyrolysis gas, and the pyrolysis gas is supplied from the pyrolysis furnace through a pyrolysis gas pipe. A method for gasifying and burning waste, in which a solid such as ash is melted in a melting furnace, and a gas and an unburned material discharged from the melting furnace are burned in a secondary combustion chamber and discharged to an exhaust gas pipe. Detecting a CO (carbon monoxide) concentration in a gas passage between the pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and the exhaust gas pipe, and detecting the detected value of the CO concentration and CO in the gas passage; Comparing the concentration of waste with the pyrolysis furnace based on the comparison result and adjusting the CO concentration in the gas passage to the allowable value or less based on the comparison result. Gasification and combustion method of waste. 11. A gas temperature in a gas passage between a pyrolysis gas pipe including the inside of the melting furnace and the secondary combustion chamber and an exhaust gas pipe, and the detected value of the gas temperature and the gas at the detection site are detected. 2. The method according to claim 1, wherein a temperature reference value is compared with the reference value, and a waste supply amount is adjusted based on a result of the comparison so that the gas temperature in the gas passage becomes the reference value.
0. Gasification and combustion method of waste according to 0. 12. A combustion assisting device for supplying a combustion assisting agent to the melting furnace, further comprising a combustion assisting amount adjusting device for adjusting a supply amount of the combustion assisting agent to the melting furnace, wherein a detected value of the CO concentration and CO 2 in the gas passage are provided. And comparing the supplied amount of the auxiliary fuel with the auxiliary fuel amount adjusting device so that the CO concentration in the gas passage is equal to or less than the allowable value based on the comparison result. Item 13. The gasification and combustion method for waste according to Item 10. 13. A gas temperature in a gas passage between a pyrolysis gas pipe including an inside of the melting furnace and a secondary combustion chamber and an exhaust gas pipe, and a detected value of the gas temperature and a gas at the detection site are detected. 13. The waste according to claim 12, wherein a comparison is made with a reference value of the temperature, and based on the comparison result, the amount of the auxiliary agent supplied is adjusted so that the gas temperature in the gas passage becomes the reference value. Gasification combustion method.