ES2461769T3 - Operating method and operating control device for gasification-melting furnace - Google Patents

Abstract

A method of operating a gasification-melting furnace (3,4) for operating said gasification-melting furnace (3,4) provided with a gasification furnace (3) for gasifying inlet waste material, an oven ( 4) melting configured to burn combustible constituents contained in pyrolysis gas produced in said gasification furnace (3) and introduced into the melting furnace (4) and melting the ash in the pyrolysis gas, and a burner (40) for auxiliary combustion provided in said melting furnace (4), said operating method comprising: the operation of stopping the operation of said burner (40) when an operating state of said gasification-melting furnace (3,4) satisfies a condition burner stop specific; the operation of stopping the loading of waste material in said gasification furnace (3) at a point in time when the temperature inside said melting furnace (4) in the vicinity of said burner (40) falls below a preset temperature of stopping the waste load after said burner (40) has stopped working; and reigning said burner (40) at a point in time when the concentration of oxygen in the gas supplied from said gasification furnace (3) to said melting furnace (4) is increased to a pre-established concentration of burner reignition after that the loading of waste material stops.

Description

Operating method and operating control device for gasification-melting furnace

Technical field

The present invention relates to an operating method and an operating control apparatus for a gasification-melting furnace for the disposal of waste such as municipal solid waste and industrial waste as well as a method and an apparatus for regulating the basicity of the slag discharged from the melting-gasification furnace.

Prior art

As a means for waste disposal, a fluidized bed gasification-melting furnace is conventionally known, for example, described in patent document 1. This fluidized bed gasification-melting furnace comprises a fluidized bed gasification furnace having a fluidized bed formed by a fluidization gas, and a melting furnace disposed downstream of it. The aforementioned fluidized bed gasification furnace produces pyrolysis gases by the partial combustion of waste thrown into the fluidized bed. The aforementioned melting furnace additionally burns the pyrolysis gases produced by the fluidized bed gasification furnace and melts the ash contained in the gases thereby producing slag. An auxiliary burner is provided at the top of this melting furnace to maintain the temperature in the oven.

This type of gasification-melting furnace has the problems mentioned below to solve with respect to the operation of the furnace.

1) About burner operation

In a state in which the internal temperature of the aforementioned gasification-melting furnace has already reached around 1,300 ° C, even if the auxiliary burner is turned off in that state, spontaneous combustion of unburned components will keep the temperature inside the Bake for a while. This causes a desire for proper stopping of the burner operation to save fuel and for environmental problems (especially in view of the restrictions on CO2 emissions).

However, after the burner stops as mentioned above, a case may occur in which the burner fails to resume combustion successfully when it is reignited. If the burner is ignited at a time when the unburned gases that exit in the vicinity of the burner have reached a temperature equal to or lower than a spontaneous ignition temperature as a result of a rapid fall in the oven temperature near the burner for one reason or another after stopping the operation of the burner, for example, abnormal combustion may arise.

2) About slag fluidity

To maintain the stable discharge of the slag through a slag outlet of the aforementioned gasification-melting furnace, it is important to maintain the fluidity of the slag. Keeping the slag fluidity low may result in a risk that the slag may clog the slag outlet to prevent continuous oven operation.

There are parameters that dominate the fluidity of the slag, which include the temperature and basicity (CaO / SiO2) of the slag. To maintain the flow of the slag, the temperature of the slag must be higher than its flow point, while the flow point has a significant correlation with the basicity of the slag. Specifically, it is known that the basicity of the slag that exceeds a value of approximately 0.7 implies an elevation of the slag flow point with an increase in the basicity. For example, it is known that the slag basicity of 1 produces a slag flow point of 1,200 ° C.

The slag basicity adjustment is therefore important for the efficient and stable continuous operation of the gasification-melting furnace. Although the melting furnace is operated to maintain its generally constant internal temperature, the actual slag fluidity is influenced by changes in its basicity. This means that stable operation is difficult without maintaining the basicity of the slag within an appropriate range. Meanwhile, if the internal temperature of the oven is set to a higher level in anticipation of the basicity changes mentioned above, a low operating efficiency cannot be avoided. For example, with the basicity of 1 of the slag, the stable discharge of the slag through the slag outlet requires that its temperature be 1,200 ° C or higher. In addition, considering that the temperature of the discharged slag tends to be lower than the temperature in the melting furnace by approximately 100-150 ° C, the temperature in the resulting melting furnace must be set at 1,350 ° C or higher for a stable discharge of the scum. Continuing such operation at high temperature for long periods of time not only implies the requirement of increasing the amount of external fuel for maintaining the internal temperature of the furnace and increasing the operating cost, but would also imply an increase in the environmental load as well. as in costs of

repair due to damage to refractory materials.

In such circumstances, it is conventionally provided to supply basicity adjusters to a system. Specifically, quartz sand (SiO2) or the like is supplied to the system to decrease basicity, while calcium hydroxide (Ca (OH) 2) or the like is supplied to the system to increase basicity. This supply of basicity adjusters in appropriate amounts within the system allows the slag basicity to be maintained within the preferable range. Simply put, determining the appropriate amounts of supply of the basicity adjusters is essential for the proper adjustment of the slag basicity.

As a method for determining the quantities of the supply of the aforementioned basicity adjusters, patent document 2 proposes a measure of the actual slag basicity by means of the use of analysis equipment. The method described in this document includes a step of analyzing the composition of the slag actually discharged from a furnace using a simplified X-ray fluorescence spectrometer, etc., and a step to determine the amount of each basicity adjuster addition based in the results of the analysis.

This method, however, involves complicated operation management. Specifically, it requires the installation of a specialized analyzer and regular analysis operations for the calculation of the slag basicity. In addition, the analyzer is generally installed in a dedicated organization away from the site, which requires the transport of slag samples from the waste disposal plant that includes the gasification melting furnace. This causes a considerable period of time from the sampling of slag to a determination of the basicity of the slag.

In addition, in this method, it is difficult to verify the reliability of the analysis results. In this method, an analysis equipment installed outside the waste facility as mentioned above is generally used, which can only perform a periodic analysis at relatively long intervals. It is extremely difficult to assess whether the results of the analyzes obtained at such infrequent intervals are valid or should be excluded as peculiar values that occurred erratically. A failure in this evaluation prevents the determination of the appropriate amount of each basicity adjuster.

Patent Document 1: Unexamined Japanese Patent Publication No. 2006-29678

Patent Document 2: Unexamined Japanese Patent Publication No. 2001-182924

US 4,013,023 describes ways and means for incinerating organic waste in a multi-hearth furnace equipped with a afterburner. JP 2004-353944 provides a waste disposal facility capable of supplying the appropriate amount of combustion air.

Description of the invention

An object of the invention is to provide a technology for carrying out the highly efficient operation of a gasification-melting furnace by stopping the burner by reliably resuming the successful combustion in the burner reignition.

To achieve this objective, after a stop of the operation of a burner for auxiliary combustion of the melting furnace, the burner is re-ignited under the following conditions: if the temperature in a melting furnace falls to a certain extent, the burner is re-ignited followed of increasing the concentration of oxygen in the gases supplied from a gasification oven to the melting furnace by stopping the loading of waste material; or the burner ignites during a period when the temperature in the melting furnace remains still quite high. This method prevents the reignition of the burner in inappropriate conditions (for example, conditions in which spontaneous ignition of gas without burning just occurs) in advance to allow the burner to re-ignite properly, carrying out a highly efficient operation by the burner stop.

Also, in the course of the present invention another objective was to provide a technology to facilitate an appropriate basicity adjuster during the operation of a gasification-melting furnace, without the need for a special analyzer for the analysis of the slag composition. To achieve this objective, the inventors undertook an intensive study of the basicity adjuster mentioned above, resulting in the discovery of a significant correlation between the calorific value per unit weight of the waste material loaded inside the gasification-melting furnace and the basicity of the slag discharged from the gasification melting furnace. This correlation can be used to allow the actual slag basicity to be determined quickly and appropriately without a special analyzer or the like.

Accordingly, in the course of the present invention there is provided a method for adjusting the basicity of the slag during the operation of a gasification-melting furnace that pyrolyzes waste material loaded therein and melts the ash in the pyrolysis gases produced by the pyrolysis to produce slag, the gasification-melting furnace having a slag discharge port to discharge the slag. This method comprises: a step of supplying a basicity adjuster to adjust the basicity of the slag discharged through the slag discharge port to a position upstream of it; a step of detecting the weight of the waste material

charged in the gasification-melting furnace per unit of time; a step of detecting a parameter that corresponds to the calorific value of the waste material per unit of weight; a step of calculating an expected value of the slag basicity produced within the gasification-melting furnace, based on a detected value of the parameter; and a step of regulating the amount of the basicity adjuster supply to make the slag basicity approximate a preset target value of the basicity, based on the calculated expected value of the basicity.

This method makes use of a correlation between the parameter corresponding to the calorific value of the waste material per unit of weight and the actual slag basicity, allowing the use to obtain the expected value of the actual slag basicity without a complicated analysis. of the composition of the slag. Specifically, the expected value of the basicity can be calculated, based on the detected value of the parameter and the aforementioned correlation. Next, based on the expected value of the slag basicity, an appropriate amount of basicity adjuster addition is determined.

This method can be performed with an apparatus to adjust the slag basicity, the apparatus comprising: a basicity adjuster feeder to supply a basicity adjuster to adjust the basicity of the discharged slag through a slag discharge port in a position upstream of the slag discharge port; a detector of the amount of waste material charge to detect the weight of waste material loaded in the gasification-melting furnace per unit of time; a parameter detector to detect a parameter that corresponds to the calorific value of the waste material per unit of weight; a calculator of the expected basicity value to calculate an expected value of the slag basicity produced within the gasification-smelting furnace based on a detected value of the parameter, and a regulator of the amount of basicity adjuster to regulate the supply quantity of basicity adjuster to make the slag basicity approach a preset target value of the basicity, based on the expected value of the basicity.

Brief description of the drawings

FIG: 1 is a general configuration diagram of a waste disposal plant provided with a gasification-melting furnace according to an embodiment of the invention;

FIG. 2 is a cross-sectional diagram showing the structure of the gasification-melting furnace;

FIG. 3 is a cross-sectional diagram showing an example arrangement of a gasification-melting furnace thermometer;

FIG. 4 is a flowchart showing an example of a control procedure for determining the timing of the burner reignition based on the concentration of oxygen in the gas in a gasification-melting furnace operating control procedure;

FIG. 5 is a flowchart showing an example of a control procedure for determining the timing of the burner reignition based on the temperature of the upper part of the furnace in a gasification-melting furnace operating control procedure;

FIG. 6 is a diagram showing an example of an installation for executing a control procedure to determine the opportune timing of the burner reignition based on a cumulative value of the amount of air in a gasification-melting furnace operating control procedure. ;

FIG. 7 is a flowchart showing an example of the control procedure for determining the timing of the burner reignition based on the concentration of oxygen in the gases in the operation control procedure of the gasification-melting furnace;

FIG. 8 is a diagram showing the overall configuration of a waste disposal plant according to an embodiment achieved in the course of the present invention;

FIG. 9 is a graph that shows an example of annual changes in the calorific value of waste and the basicity of slag;

FIG. 10 is a graph showing an example of a correlation between the calorific value of the waste and the basicity of the slag; Y

FIG. 11 is a graph showing an example of setting the amount of basicity adjuster to be supplied based on an expected value of the slag basicity.

The best ways of carrying out the invention

A preferred embodiment of the invention is described with reference to FIGS. 1 to 7

FIG. 1 shows an example of a waste disposal plant equipped with a gasification-melting furnace

of fluidized bed. The present invention is generally applicable to the operation of a gasification melting furnace having a gasification furnace and a melting furnace. The general configuration of the waste disposal plant that adopts the gasification-melting furnace is not particularly limited.

Referring to FIG. 1, waste materials, that is, waste items are placed before in a waste pit 1 and thrown into a hopper 2a of a waste feeder 2 that serves as a waste feeder by means of a crane not represented The waste feeder 2 feeds the waste to a fluidized bed gasification furnace 3 in the prescribed amounts.

This gasification furnace 3 performs a partial combustion process under conditions of an air ratio, for example from 0.2 to 0.4, that is, a pyrolysis or primary combustion process, with a fluidized bed that includes a layer of sand that is maintained at a temperature of 450ºC to 650ºC. The non-combustible material contained in the wastes thrown into the waste feeder 2 is removed from the bottom of the oven and transported via a screw conveyor 5, a vibrating screen 6 and a magnetic separator not illustrated to be separated into non-combustible objects, metals non-ferrous, ferrous metals and fluidized sand. The fluidized sand between them is returned to the area layer in the gasification oven 3 for reuse.

The pyrolysis gases produced in the gasification furnace 3 are conducted to a melting furnace 4 to be further burned there under conditions of an air ratio of 1.3, for example. A high temperature combustion process is performed in this melting furnace 4 at about 1,300 ° C with a spiral flow produced therein. This high temperature combustion generates heat, which melts the ash contained in the pyrolysis gases to separate the ash as slag from the pyrolysis gases by decomposing the hazardous substances such as dioxins contained in the gases. The molten slag is removed from the bottom of the melting furnace 4, carried out by means of a slag removal unit 7 that includes a conveyor, cooled in a slag cooling unit 8 provided hereinafter, and collected then.

Exhaust gases discharged from the turbulent melting furnace 4 are conducted through an air heater 9 and a heat recovery boiler 10, in which heat is recovered from the pyrolysis gases. The exhaust gases after heat recovery are further cooled in a gas cooling unit 11 and dusted by means of a bag filter 12. Exhaust gases cleaned in this way are conducted by means of an induced draft fan 13 through the denitration unit 14 to be expelled through a chimney 15.

FIG. 2 shows details of the structure of the gasification-melting furnace configured with the gasification furnace 3 and the melting furnace 4.

Referring to Fig. 2, a dispersion plate 20 is provided having a large number of gas injection holes 22 at the bottom of the gasification furnace 3, a wind box 24 formed under the dispersion plate 20. From the wind box 24, fluidization gas is expelled, for example, upwardly through the gas injection holes 22 in the dispersion plate 20, thereby forming a fluidized bed 26 of sand particles above the plate 20 dispersion. The center of the dispersion plate 20 is provided with an outlet 28 of non-combustible material, through which the non-combustible material is removed to be driven to the screw conveyor 5 and vibrating screen 6.

Above the fluidized bed 26 a waste inlet port 30 is provided connected to the waste feeder 2. A discharge valve 32 is provided on a path between the waste inlet port 30 and the waste feeder 2 to open and close the path. At around the same height as the waste inlet port 30 a burner 34 is provided to heat the gasification furnace. Additionally, a free housing 36 for secondary combustion is formed above the burner 34 for heating the gasification furnace. A port 38 of pyrolysis gas outlet is provided at the top of the oven.

The pyrolysis gases discharged through the outlet port 38 of the pyrolysis gas are fed to the upper portion of the melting furnace 4. In a suitable location (the upper part of the furnace in the illustrated example) of the turbulent flow furnace 4, a burner 40 for auxiliary combustion is provided down. Immediately below this burner 40, a port 42 of pyrolysis gas inlet is provided, which is connected to the pyrolysis gas outlet port 38 of the gasification furnace 3 via a line 44 which serves as a pyrolysis gas channel. The burner 40 is used to raise and maintain the temperature of the melting furnace 4 (for example, to maintain a state at a temperature of 1,300 ° C or higher). The operation of this burner 40 will then be described in detail.

In addition, the melting furnace 4 is provided with a slag discharge port 43 at its bottom, to which the slag removal unit 7 is connected.

The conduit 44 is provided with an oxygen analyzer 45, which detects the concentration of oxygen contained in the gas feed of the gasification furnace 3 to the melting furnace 4. In the vicinity the burner 40 (that is, at a location near the top of the turbulent melting furnace 4 in this embodiment), a thermometer 46 is provided to detect the temperature in the furnace at the location (i.e., the temperature at the top of the oven in this embodiment).

The oxygen analyzer 45 preferably has superior durability. It is specifically preferable, for example, a zirconia type oxygen analyzer.

The thermometer 46 preferably has superb durability and excellent measurement accuracy in a high temperature range. Specifically, a radiation pyrometer (especially an infrared radiation pyrometer) or the like is preferable. The location of this thermometer 46, although it is possibly determined to be appropriate within a detectable range for the temperature of the upper part of the oven, is preferably determined to allow monitoring as stable as possible. For example, in the case where a combustion air supply nozzle 48 is provided for the melting furnace shown in FIG. 3 near the pyrolysis gas inlet port 42 of the melting furnace 4, the thermometer 46 is preferably disposed in a position upstream of the nozzle 48, from which the thermometer 46 can monitor the inside of the upper part of the furnace 4 melting through the nozzle 48, as illustrated. This location of the thermometer 46 allows a flow of combustion air to be used from the nozzle 48 to the interior of the melting furnace 4a to prevent ash or the like in the melting furnace 4 from obstructing a thermometer detection window 46, by this a temperature monitoring in a stable way.

The position of the thermometer 46 can be chosen within a range near the burner 40, especially in an interval so close to the burner 40 that ignition of the burner 40 can cause combustion of the unburned gases.

This gasification-melting furnace is additionally provided with a control system 50 shown in FIG. 2, in which output signals (detection signals) of the oxygen analyzer 45 and the thermometer 46 are individually input.

This control system 50 is configured with a computer etc., which functionally includes a burner control section 52 and a waste feeder control section 54. The burner control section 52 generates the respective order signals to effect the temporary stop and the reignition of the burner

40. Control section 54 of the waste feeder generates the respective order signals to effect the temporary closure and opening of the waste feeder 2.

The operation of this gasification-melting furnace and an operation control procedure performed by the control system 50 are also described below with reference also to a flow chart of FIG.

Four.

In a "normal operating state" (step S1) shown in FIG. 4, the waste feeder 2 is activated and the burner 40 of the melting furnace 4 has been ignited. In this normal operating state, the waste feeder 2 feeds waste such as municipal solid waste to the gasification furnace 3 through the furnace waste inlet port 30 3. The wastes are carried to a primary combustion in the fluidized bed 26 inside the oven 3, thereby producing pyrolysis gases. The pyrolysis gases are fed from the pyrolysis gas outlet port 38 in the upper part of the furnace to the pyrolysis gas inlet port 42 of the melting furnace 4 through the conduit 44 and are introduced in the upper part from oven 4 through the inlet port 42. In the melting furnace 4, the combustible constituents in the pyrolysis gases are additionally burned at high temperature, thereby producing heat that melts the ash contained in the slag-shaped gas. This slag adheres to the oven walls, and additionally flows down to the slag discharge port 43 at the bottom of the oven to be removed outside the oven.

The temperature in the upper part of the melting furnace 4 is kept high by means of the burner 40 already lit. However, with the temperature of the top of the oven already at 1,300 ° C, spontaneous combustion of unburned components can keep the temperature in the oven high for a while, even if the auxiliary burner operation stops. Therefore, from a fuel saving and environmental issues point of view (in view of the restrictions on CO2 emissions), an appropriate stop of the burner operation is desirable.

For this reason, when a present operating state coincides with a preset burner stop state (step S2), the control system 50 generates a burner stop order signal (step S3) to stop the operation of the burner 40.

The burner stop conditions can be set in several ways. For example, the state may preferably include the following.

1) A state has been maintained in which the temperature of the upper part of the oven detected by the thermometer 46 is equal to or greater than a pre-set temperature of the burner stop (for example, 1,100 ° C), for a specific period of time ( for example, 30 minutes). An estimate of the "temperature of the upper part of the oven" can be made by checking an instantaneous value at appropriate sampling intervals or based on a moving average value of the temperature of the upper part of the oven for an appropriate period of time (for example , the aforementioned specific time period). Establishing this 1) as a condition has an advantage of allowing the thermometer 46 to confirm compliance with the condition also be used as a means to make a choice to stop the waste load described below or to restart the

burner

2) A moving average value of low calorific values is equal to or greater than a preset calorific value (for example 2,000 kcal / kg). The "low calorific value" referred to here means the amount of heat possessed by the wastes fed by the waste feeder 2 to the gasification oven 3 per unit of time, which corresponds to the amount of heat of the waste material.

The amount of heat possessed by the wastes, possibly calculated from the heat balance of the waste disposal plant, for example, as described in Japanese Unexamined Patent Publication No. 2004-37049, can be considered approximately equal to the Q generation of calculated exhaust gas heat based on the exhaust gas flow rate Fe (Nm3 / h) detected by an exhaust gas flowmeter provided at a location downstream of the bag filter 12 and the temperature of the Exhaust gas Te (ºC) detected by an exhaust gas temperature sensor provided in a similar location. Specifically, given the specific heat cE of the exhaust gas, the Q (kcal / h) generation of exhaust heat is expressed in the following equation:

Q = cE x Fe x Te

For a more precise calorific calculation, the heat input by other means (for example, air, water and auxiliary fuel of the burner 40) and the heat generation by these means, in addition to the heat generation Q of the heat exhaust gas, for the calculation of the calorific value.

Only one or both of 1) and 2) mentioned above can be used as a burner stop condition. Specifically, burner 40 may be caused to stop when at least one of 1) and 2) is satisfied or when both of 1) and 2) are satisfied.

The result of the burner detection order signal in step S3 can be used directly as a control signal, or used as a notification signal for an operator. In the previous case, the burner stop order signal can perform automatic control of the burner 40, when it enters a burner actuator 40. In the latter case, the stop burner order signal can be entered for example in an operation panel to display an indicator on the operation panel, thereby notifying the operator of an appropriate burner stop time to allow it to stop the operation of the burner 40, by manual intervention, at an appropriate time.

After stopping the operation of the burner 40, the burner 40 is re-ignited at an appropriate time. If the burner 40 is reignited at a temperature equal to or lower than the temperature of spontaneous ignition of the unburned gases after the temperature of the upper part of the oven has become the same

or below the temperature of spontaneous ignition for one reason or another after a temporary stop of the burner 40, the reignition of the burner 40 can potentially induce an explosion depending on the concentration of unburned gases.

Accordingly, the control system 50 of this embodiment sends the stop order signal of the waste load to stop the waste loading operation of the waste feeder 2 (step S5) at a point in time when the temperature of the upper part of the oven detected by the thermometer 46 falls below a pre-set temperature for stopping the waste load (900 ° C in this embodiment) (If in step S4). Similar to the burner stop order signal, the stop load stop signal can also enter directly into, for example, a motor portion of the waste feeder 2 to function as a signal to automatically stop the operation of waste load from waste feeder 2, or it may enter the operation panel and the like to turn on its indicator to function as a signal to notify the operator of an appropriate time to stop the waste load.

In step S4 above, the stop order signal of the waste load can be produced immediately upon lowering the temperature of the upper part of the oven to the stop temperature of the waste load. However, to exclude the risk of reignition at a point in time when the temperature of the top of the furnace has suddenly dropped for one reason or another, it is preferable that the stop order signal of the waste load occurs afterwards. of a state in which the temperature of the upper part of the furnace has decreased until the stopping temperature of the waste load has continued for a specific period of time (for example, from 2 to 20 seconds).

The aforementioned stoppage of the waste loading operation increases the concentration of oxygen contained in the gases fed from the gasification furnace 3 to the melting furnace 4 to create a safe state for the reignition of the burner 40 inside the furnace 4 fusion. In view of this, the control system 50 monitors the concentration of oxygen in the gases detected by the oxygen analyzer 45 and produces a burner reignition order signal (step S8) at a point in time when the concentration has reached at a pre-set concentration of burner reignition (10% in this embodiment) (If in step S6).

If the oxygen concentration has not increased to the burner reignition concentration, the control system 50 sends the burner reignition order signal at a point in time when the temperature of

the upper part of the oven reaches a specific temperature (950 ° C in this embodiment) higher than the burner re-ignition temperature due to an increase in the temperature of the upper part of the oven for one reason or another (If in step S7). Like the burner stop signal, this signal can also be sent directly to the burner actuator 40 to automatically re-ignite the burner 40, or it can be sent to the operating panel to indicate to the operator an appropriate burner re-ignition time.

After that, verifying that the waste feeder 2 is ready to restart (If in step S9), the control system 50 produces a reset command signal to the waste feeder 2 to restart it (step S10). This restart stage can also be performed manually by the operator.

The operation described above ensures a high degree of safety of burner reset 40 in order to save fuel and suppress CO2 emissions by stopping the burner at the appropriate time.

Another example of operation to ensure such a high degree of safety is shown in FIG. 5. The operation control procedure shown in this Figure includes operation to a point of producing the burner reignition order signal (step S3) that is equal to what is shown in FIG. 4. After the production of that signal, the control system 50 produces the burner reignition order signal (step S12) at a point in time when the temperature of the top of the oven has fallen to a pre-set temperature of burner reignition (1000 ° C in this embodiment) (If in step S11).

The burner reignition temperature is set at such a high temperature as to reliably prevent abnormal combustion of unburned gases due to the burner 40 reignition at that temperature to thereby ensure a high degree of safety. In general, a temperature at which safety has been ensured by test or the like is desirably employed, the temperature being obtained by multiplying the temperature of spontaneous ignition of unburned gases (appropriately 680 ° C in the case of natural gas, for example) by A sufficient safety factor.

This type of operation can also prevent excessive cooling of the interior of the melting furnace 4 in advance and ensure a high degree of re-ignition safety of the burner, reigning the burner 40 during the temperature drop in the oven shortly after the temporary stop of the burner 40.

This operation can be carried out in combination with the operation shown in FIG. 4, that is, the operation of stopping the waste load to increase the concentration of oxygen in the gases at the exit port of the gasification furnace, to provide a fault insurance feature in the event that the burner 40 is not close even when the burner reignition order signal occurs in step S12 or it becomes impossible to produce this signal.

The operation control procedure shown in FIG. 4 includes determining the rate of burner reignition based on the concentration of oxygen in the gas after stopping the waste loading operation; however, as a parameter that directly affects the oxygen concentration, a cumulative value of the amount of air supplied to a lateral upstream from the melting furnace 4 after stopping the waste loading operation can be monitored, to determine the burner reignition time based on this cumulative value. An example of this will be described with reference to FIGS. 6 and 7.

An installation shown in FIG. 6 with a fan 60 and a flow meter 62. The fan 60 is for supplying air to the gasification oven 3, air that is supplied inside the wind box 24 of the gasification oven 3 as a fluidization gas, and is supplied additionally inside the free housing 36 as purge air in some cases. The pyrolysis air outlet port 38 is provided at the top of the oven. The flow meter 62 is provided at a side outlet of the fan 60 to detect the flow of air supplied from the fan 60 to the gasification oven 3 and produce a detection signal relative to the detected flow rate. This detection signal is introduced into the control system 50.

FIG. 7 shows the control operation of the control system 50. FIG. 7 shows the operation to a point of producing the waste load stop order signal (steps S1-S5) that is equal to the operation performed in the control procedure shown in FIG. 4. After the production of the waste load stop order signal, the burner control section 52, from a point in time when the waste load operation is stopped, accumulates the amount of air supplied to the gasification oven 3 based on the aforementioned detection signal (step S6A), and produces the burner reignition order signal (step S8) at a point in time when the cumulative value obtained in this way reaches a fixed value preset (If in step S6B).

This control operation also allows the burner 40 to be restarted at a time when the oxygen concentration in the vicinity of the burner 40 can be assumed to have increased to some extent as a result of the supply of air from the fan 60 after stopping. temporary burner

40. This serves to ensure a high degree of safety at the time of resetting the burner 40.

The air subjected to the aforementioned accumulation stage includes air that is thus supplied to the side updraft of the melting furnace 4 to contribute to an increased concentration of oxygen within the melting furnace 4. This air is therefore not limited to the air supplied to the interior of the gasification oven 3. For example, the purge air, if supplied to the line 44 provided between the gasification furnace 3 and the melting furnace 4, is also included in the air subjected to the accumulation stage.

As further described in this way, the present invention provides a method of operation for operating a gasification-melting furnace provided with a gasification furnace for gasifying inlet waste material, a melting furnace configured to burn combustible constituents contained in the pyrolysis gas produced in said gasification furnace and introduced into the melting furnace and melting ash in the pyrolysis gas, and a burner for auxiliary combustion provided in the melting furnace. This method of operation comprises: stopping the operation of the burner when a state of operation of the gasification-melting furnace satisfies a specific condition of stopping the burner; stop loading the waste material in the gasification furnace at a point in time when the temperature inside the melting furnace in the vicinity of the burner falls to a stop temperature of the preset waste load after the operation of the burner It has stopped; re-ignite the furnace at a point in time when the concentration of oxygen in the gas supplied from the gasification furnace to the melting furnace is increased to a pre-set burner re-concentration concentration after the loading of the waste material is stopped.

The position in which the “temperature inside the melting furnace in the vicinity of the burner” is detected, can be properly determined within a range in which the reignition of the burner can cause combustion of unburned gas.

The expression "stop loading the waste material in the gasification furnace at a point in time when the temperature inside the melting furnace in the vicinity of the burner falls to a pre-set temperature of stopping the waste load" includes not only stop loading the waste material at the time when the temperature inside the gasification furnace has fallen from the stopping temperature of the waste load, but also stop loading the waste material after a state in which the temperature of Detention of the waste load has continued for a pre-established period of time, to exclude a case of sudden temperature drop from the top of the oven.

According to this method of operation, at a point in time when the temperature inside the melting furnace in the vicinity of the furnace falls to a stop temperature of the waste load (for example, in the appearance of a temperature state in the that spontaneous combustion of unburned gas has become difficult) after the operation of the burner stops, first, stopping the loading of waste material in the gasification oven can increase the concentration of oxygen in the gas supplied from the oven from gasification to the melting furnace, and then the reignition of the burner at a point in time when the oxygen concentration has increased to the pre-established burner reignition concentration can ensure the prevention of abnormal combustion of the burning gas due to the reignition, thus ensuring combustion successfully.

Meanwhile, at a point in time when the temperature inside the melting furnace in the vicinity of the burner is increased to a pre-set temperature greater than the stopping temperature of the waste load (for example, a temperature high enough to prevent abnormal combustion of unburned gas) after the burner has stopped functioning, the burner can be re-ignited regardless of the oxygen concentration.

In this method of operation, after the operation of the burner stops when the operating state of the gasification furnace satisfies a specified condition of stopping the burner, the burner can be re-ignited at a point in time when the temperature inside the oven melting in the vicinity of the burner has dropped to the stop temperature of the preset waste load. This approach can also prevent the reignition of the burner in one of its excessively low temperature ranges (for example, a temperature range in which spontaneous combustion of unburned gas hardly occurs), thereby ensuring successful combustion.

The burner stop condition can be set as appropriate. However, if this burner stop condition is a condition such that the temperature inside the melting furnace in the vicinity of the burner or one of its moving average values has remained equal to or greater than a pre-set burner stop temperature during a specific period of time, means can be used to detect the aforementioned temperature to choose the moment of stopping of the waste load or the moment of reignition of the burner as well as deciding on the condition of stopping the burner.

In this method of operation, after stopping the operation of the burner when the operating state of the gasification-melting furnace satisfies the specific condition of stopping the burner and stopping the loading of waste material in the gasification furnace at a point in the time when the temperature inside the melting furnace in the vicinity of the burner falls below the waste loading temperature

preset after the burner has stopped operation, the operation to reignite the burner can be performed when the cumulative value of the amount of air supplied to the upstream side of the melting furnace from a point in time when the material load of waste stops it reaches a set value. This performance allows a reignition ensuring a sufficient oxygen concentration in a combustion range of the burner, thereby ensuring successful combustion.

An operation control apparatus for carrying out the above-mentioned method of operation is provided with an apparatus comprising: a waste feeder for loading the waste material in the gasification furnace; a thermometer to detect the temperature inside the melting furnace in the vicinity of the burner; an oxygen analyzer to detect the concentration of oxygen in the gas feed from the gasification oven to the melting furnace; and a control system to control the operation of the gasification furnace based on the detection results of the thermometer and the oxygen analyzer. The aforementioned control system includes a burner controller that produces a burner stop order signal to stop the burner operation when a gasification-melting furnace operating state satisfies a specific burner stop condition, and a controller of waste load that produces a waste load detection order signal to stop the waste load from loading the waste material in the gasification furnace at a point in time when the temperature detected by the thermometer falls below a stop temperature of the waste load after the burner has stopped working. The burner controller produces a burner reignition order signal at a point in time when the oxygen concentration detected by the oxygen analyzer is increased to a pre-set concentration of burner reignition after the waste feeder has stopped Load waste material.

In this apparatus, after the burner has stopped working, the burner controller can produce the burner reignition signal without taking into account the oxygen concentration at a point in time when the temperature inside the melting furnace in the Burner vicinity detected by the thermometer is increased to a preset temperature higher than the waste load stop temperature.

Also provided as another operation control apparatus for carrying out the aforementioned method of operation is an apparatus comprising: a waste feeder for loading waste material in a gasification furnace; a thermometer to detect the temperature inside a melting furnace in the vicinity of a burner; and a control system to control burner operation based on thermometer detection results; wherein the control system produces a burner stop signal to stop the burner operation when a gasification-melting furnace operating state satisfies a specific burner stop condition as well as a burner reignition signal to reset the burner. burner operation at a point in time when the temperature detected by the thermometer falls below a pre-set concentration of burner reignition after the burner has stopped operation.

It is preferable that the burner stop condition of the above described apparatus includes that the temperature detected by the thermometer or its moving average value has been maintained equal to or greater than a preset burner stop temperature for a specific period of time.

Also provided as another operation control apparatus for effecting the above-described method of operation is an apparatus comprising: a burner controller that produces a burner stop signal to stop the operation of a burner when an oven operating state gasification-fusion satisfies a specific burner stop condition; and a waste charge controller that produces a stop loading order signal to stop a waste feeder from loading the waste material in a gasification oven at a point in time when the temperature detected by a thermometer drops below a pre-set temperature for stopping the waste load after the burner has stopped operation, in which the burner controller accumulates the amount of air detected by a detector of the amount of air from a point in time when the waste feeder has stopped loading the waste material and generates a burner reignition signal to restart the burner operation at a point in time when a cumulative value obtained in this way reaches a predetermined fixed value.

Each of the operation control devices described above can configure an excellent gasification-melting furnace in combination with a gasification furnace for gasifying inlet waste material, a waste feeder for loading waste material into the gasification furnace, a melting furnace configured to burn combustible constituents contained in the pyrolysis gas produced in said gasification furnace and introduced into the melting furnace and melting the ash in the pyrolysis gas, and a combustion burner provided in the melting furnace.

An embodiment is described below as obtained in the course of the present invention with reference to FIG. 8.

FIG. 8 shows the global configuration of a waste disposal plant that includes a furnace

gasification-fusion to which the present second invention is applied. This plant is provided with a gasification-melting furnace 110, a waste feed section 112 for feed waste materials, that is, waste articles for the gasification-melting furnace 110 and a gas treatment section 114 for treating gases discharged from the gasification-fusion furnace 110.

The waste feed section 112 is equipped with a waste pit 116, a waste conveyor 118 and a waste feeder 120. Waste pit 116 receives and stores beforehand the waste items to be treated that are carried from outside the plant. The waste conveyor 118, provided with a crane, grabs the waste in the waste pit 116 and moves it to the waste feeder 120. The waste feeder 120 has a hopper 122, which receives the waste fed from the waste conveyor 118. The amount of charged waste corresponds to a load amount of waste fed to the gasification-melting furnace 110. The waste feeder 120, which incorporates a screw conveyor, supplies the waste thrown into the hopper 122 for the gasification-melting furnace 110.

The gasification-melting furnace 110 has a gasification furnace 124 and a melting furnace 126. The gasification furnace 124 effects the pyrolysis of the wastes loaded from the waste feeder 120, thereby producing pyrolysis gases. As gasification furnace 124, for example, a known fluidized bed kiln or kiln can be used. The melting furnace 126 burns the combustible constituents in the high temperature pyrolysis gases to melt the ashes contained in the slag-shaped gases. The slag adheres to the furnace wall of the melting furnace 126, for example. The melting furnace 126 is provided with a slag discharge port 128 at the bottom of the furnace. The slag discharge port 128 is for discharging the slag that adheres to the oven wall and flows down from there to the outside of the oven. In this melting furnace 126, combustion of auxiliary fuel is carried out by means of a burner not drawn to adjust the temperature inside the furnace.

The gas treatment section 114 is provided with a heat recovery boiler 130, a cooling chamber 132, a dust collector 134, an induced draft fan 136 and a chimney 138.

The heat recovery boiler 130 is for recovering heat from the high temperature exhaust gas discharged from the melting furnace 126, specifically to produce water vapor using the heat possessed by the exhaust gas and discharging the water vapor. The flow rate of the water vapor stream, that is, the amount of water vapor produced in the heat recovery boiler 130 per unit of time, serves as a parameter corresponding to the calorific value of the wastes loaded in the gasification furnace 110 -fusion per unit of time.

The cooling chamber 132 is equipped with a tower structure in which the gas discharged from the heat recovery boiler 130, a sprayer for spraying cooling water into the tower structure, a temperature sensor to detect is introduced the temperature of the gas at an outlet of the tower structure and a controller to regulate the flow of the cooling water supplied by the sprayer to make the temperature of the outlet gas detected by the temperature sensor remain constant.

The dust collector 134 captures dust or the like contained in the gas discharged from the cooling chamber 132. The dust-free gas from the dust collector 134 is discharged through the chimney 138 via the induced draft fan 136.

This plant additionally includes a basicity adjuster unit 140. The basicity adjuster unit 140, to adjust the basicity of the slag discharged through the slag discharge port 128 of the melting furnace 126, comprises a feeder 142 of the basicity adjuster, a water vapor flow meter 144, a production portion 146 of the amount of waste load and a controller 150.

The feeder 142 of the basicity adjuster, for supplying a basicity adjuster to the wastes loaded in the gasification furnace 124, comprises a screw conveyor 147 which serves as a means of transport for supplying the basicity adjuster and a motor 148 for moving the screw conveyor 147. The basicity adjuster is selected appropriately. This embodiment is intended only for excessively high basicity of the discharged slag, so that quartz sand (SiO2) basicity adjuster is selected to decrease the basicity of the slag.

The water vapor flow meter 144 measures the flow rate of the discharged water vapor, that is, the amount of water vapor produced in the heat recovery boiler 130 per unit of time.

The production portion 146 of the amount of waste load produces an information signal regarding the weight of the waste loaded in the gasification oven 124 per unit of time. Specifically, the production portion 146 of the amount of waste load is additionally provided to the waste conveyor 118 to calculate the amount of waste transported based on the weight load applied to the waste conveyor 118 and the number of transport operations, and to provide it to controller 150 as information regarding the amount of waste loading in the gasification-melting furnace 110.

The controller 150, configured with a microcomputer etc., has a function of fully controlling the entire plant, including a calculator 152 of the expected basicity value and a regulator 154 of the amount of adjuster of

basicity to serve as a function to adjust the basicity of the slag.

The calculator 152 of the expected basicity value calculates an expected value of the basicity of the slag discharged from the slag discharge port 128, based on the information signal regarding the weight of the waste loaded in the gasification furnace 124 per unit of time and of the water vapor flow rate measured by the water vapor flow meter 144. The calculation of this expected value is achieved by a step of calculating the calorific value of the waste per unit of weight based on the amount of waste loaded per unit of time and the flow rate of the water vapor and a step of calculating the expected value of the basicity based on the calorific value of the waste per unit of weight.

There is a correlation between the discharge of the water vapor discharged or the calorific value of the waste per unit of weight and the basicity of the slag. This correlation can be predetermined by real measurements. Specifically, measuring the actual slag basicity that corresponds to the water vapor flow rate by means of an analyzer during a particular period of time allows the correlation to be estimated, as shown in the Examples discussed below. The correlation can be expressed approximately, for example, in a first degree equation (linear equation).

The calculator 152 of the expected basicity value stores the correlation and calculates the expected value of the basicity based on the correlation and the water vapor flow measured in fact by the water vapor flow meter 144.

As the flow rate of the discharged water vapor on which the calculation of the expected value of the basicity is based, an average value of the values of the flow meter 144 is adopted over a specific period of time. This period of time can be established as appropriate, preferably in about 6 to 24 hours in general terms.

The regulator 154 of the amount of basicity adjuster determines the amount of basicity adjuster supplied to make the basicity approximate a preset target value (e.g. 0.5), based on the expected value of the slag basicity calculated by calculator 152 of the expected basicity value and the information signal with respect to the weight of the input of waste loaded from the production portion 146 of the amount of waste load. Then, to obtain the determined quantity of supplies, the regulator 154 of the basicity adjuster quantity produces a control signal for the motor 148 of the feeder 142 of the basicity adjuster to control its rotation speed. A relationship between the expected value and the actual amount of basicity adjuster supply can be prepared in advance, based on theory or simulation.

In the above-described apparatus and method of adjustment of the slag basicity carried out in this apparatus, centered on the parameter (flow of water vapor discharged from the heat recovery boiler 130 here) with respect to the calorific value of the waste that is closely related to the basicity, the expected value of the basicity is calculated based on the detected values of that parameter and the relationship. This allows the amount of basicity adjuster to be supplied to be determined quickly and appropriately with a simple configuration using an existing plant, contrary to a conventional method in which the operation is carried out by means of a parallel measurement of the actual basicity of slag by an analyzer.

This method can be carried out even within a plant that does not include the aforementioned heat recovery boiler 130. In this case, for example, with respect to the calorific value of the waste, a flow rate of the cooling water supply in the cooling chamber 132 can be selected. Since this cooling chamber 132, as previously described, is provided with a temperature sensor to detect the temperature of the gas at the outlet of the tower structure and controller to regulate the flow of the cooling water supply by the sprayer to keep the temperature of the outlet gas detected by the temperature sensor constant, the flow rate of the cooling water supply corresponds to the calorific value of the waste loaded in the gasification-melting furnace 110 per unit of time.

The feed position of the basicity adjuster is not limited to a side inlet of the gasification furnace 124, allowed to be properly determined in a range upstream of the slag discharge port 128. For example, the position can be determined within a range between the gasification furnace 124 and the melting furnace 126 or within a combustion chamber of the melting furnace 126 upstream of its slag discharge port 128.

Examples (are not part of the present invention)

Examples are described here regarding the adjustment of the slag basicity in the waste disposal plant shown in FIG. 8

1) About the correlation between calorific value of waste per unit weight and slag basicity.

There is a correlation between the calorific value of the wastes per unit of weight and the basicity of the slag, a correlation that can be assumed to be approximately a first degree function.

FIG. 9 shows the annual changes in the calorific value of the waste per unit of weight (kcal / kg) and the basicity of the slag in a certain waste disposal plant. This figure clearly indicates that the calorific value of the wastes and the basicity vary similarly with each other.

FIG. 10 is a graphic representation of the respective relationships between the calorific value of the waste and the basicity of the slag determined by the actual measurements in two waste disposal plants (plant A and plant B). As shown in this Figure, any of the plants A and B has a specific relationship between the calorific value of the waste and the basicity of the slag. The two plants A and B are so different from each other in components of the waste loaded in their gasification-melting furnaces that the respective relationships between the calorific value of the waste and the basicity of the slag in plants A and B differ from each other. , although both relationships can be approximately assumed to be first degree functions. Therefore, each relationship, when entered and stored in the calculator 152 of the expected basicity value in advance, allows the calculator 152 to quickly calculate an expected value of the slag basicity based on the parameter corresponding to the calorific value of the waste (for example, flow of water vapor discharged from heat recovery boiler 30).

2) About the relationship between expected slag basicity value and basicity adjuster amount.

It is possible to determine the relationship between the expected value of the slag basicity and the amount of basicity adjuster supply in advance based on theory or simulation. For example, with the assumption of only downward adjustment of the slag basicity, it is preferably preset as shown in FIG. 11 a relationship between the amount of basicity adjuster (for example, quartz sand) to be supplied (the amount of supply corresponding to the amount of waste loaded per unit of time) and the expected value of the basicity. According to this setting, when the expected value of the basicity exceeds an objective value (for example, 0.5), the basicity adjuster is supplied in an amount corresponding to an amount in excess of the expected value.

As so far described in this way, this embodiment provides a method for adjusting the basicity of the slag by operating a gasification-melting furnace that pyrolyzes charged waste material and melts the ashes into the pyrolysis gas produced by the pyrolysis, the gasification-melting furnace having a slag discharge port to discharge the slag produced by melting the ash. Understanding the basicity adjustment method: a step of supplying a basicity adjuster to adjust the basicity of the slag discharged by the slag discharge port in a position upstream of it; a step of detecting the weight of the waste material loaded in the gasification-melting furnace per unit of time; a step of detecting a parameter that corresponds to the calorific value of the waste material per unit of weight; a step of calculating an expected value of the slag basicity produced within the gasification-melting furnace based on a detected value of the parameter, and a step of regulating the supply amount of the basicity adjuster to a predetermined target value of the basicity , based on the calculated expected value of the basicity.

In this basicity adjustment method, which uses a correlation between the parameter corresponding to the calorific value of the waste material per unit of weight and the actual slag basicity to be obtained without a complicated analysis of the slag composition. In summary, the expected value of the basicity can be calculated based on the detected value of the parameter and the correlation Based on the expected value of the slag basicity, an appropriate amount of the basicity adjuster addition is determined.

Specifically, as a parameter corresponding to the calorific value of the waste material per unit of weight, an amount of water vapor produced in a heat recovery boiler per unit of time is effectively detected by the use of the gas heat discharged from the gasification furnace -fusion. The amount of water vapor production is easily detected. Furthermore, based on the amount of water vapor produced in this way and the amount of waste material loaded in the gasification-melting furnace per unit of time, the calorific value of the waste material per unit of weight can be properly calculated. .

As a specific means to calculate the expected value of the basicity, for example, a method that includes a step of determining a relationship between the parameter and the actual slag basicity by the actual measurement is effective, in advance of the step of calculating the expected value of the slag basicity produced in the gasification-melting furnace, in which the expected value of the basicity is calculated based on the ratio and the detected value of the parameter. In this method, an appropriate expected value of the slag basicity is quickly calculated based on the relationship between the predetermined parameter and the actual slag basicity.

An apparatus for adjusting the basicity of a gasification-melting furnace is also provided to effect the aforementioned basicity adjustment method. This apparatus comprises: a basicity adjuster feeder for supplying a basicity adjuster to adjust the basicity of the slag discharged by a slag discharge port in a position upstream of it; a detector of the amount of waste material charge in the gasification-melting furnace per unit of time; a parameter detector to detect a parameter that corresponds to the calorific value of the waste material per unit of weight; a basicity value calculator expected to calculate an expected value of the slag basicity produced within a gasification-melting furnace based on a detected value of the parameter; and a regulator of the amount of basicity adjuster to regulate the amount of basicity adjuster supply so that the slag basicity approaches a preset target value of the basicity, based on the expected value of the basicity.

The parameter detector of this apparatus, for example, preferably detects the amount of water vapor produced in a heat recovery boiler per unit of time by the use of heat from the gas discharged from the

5 gasification-melting furnace. In this case, the expected basicity value calculator can calculate the calorific value of the waste material per unit of weight based on the parameter detected by the parameter detector and the amount of waste material loaded in the gasification-melting furnace per unit of time.

Also, the regulator of the amount of basicity adjuster, for example, preferably stores a relationship between the parameter determined by the actual measurement and the actual basicity of the slag, and determines the amount of the

10 supply of basicity adjuster based on the ratio stored in this way and the detected value of the parameter.

Claims (6)

1. A method of operating a gasification-melting furnace (3,4) for operating said gasification-melting furnace (3,4) provided with a gasification furnace (3) for gasifying inlet waste material, a melting furnace (4) configured to burn combustible constituents contained in pyrolysis gas produced in said gasification furnace (3) and introduced into the melting furnace (4) and melting the ash in the pyrolysis gas, and a burner (40 ) for auxiliary combustion provided in said melting furnace (4), said operating method comprising: the operation of stopping the operation of said burner (40) when a state of operation of said gasification-melting furnace (3,4) satisfies a specific condition of stopping the burner; the operation of stopping the loading of waste material in said gasification furnace (3) at a point in time when the temperature inside said melting furnace (4) in the vicinity of said burner (40) falls below a preset temperature of stopping the waste load after said burner (40) has stopped working; Y reigning said burner (40) at a point in time when the concentration of oxygen in the gas supplied from said gasification furnace (3) to said melting furnace (4) is increased to a pre-established concentration of burner reignition after waste material loading stops.

2.

The method of operation of the gasification-melting furnace as described in claim 1, wherein said burner (40) is ignited without taking into account the concentration of oxygen at a point in time when the temperature inside said furnace ( 4) melting in the vicinity of said burner (40) is increased to a preset temperature higher than the stopping temperature of the waste load, after said burner (40) has stopped working.

3.

The method of operation of the gasification-melting furnace (3,4) as described in claim 1

or 2, wherein the burner stop condition includes that a state in which the temperature within said melting furnace (4) in the vicinity of said burner (40) or its moving average value is equal to or greater than a Preset burner stop temperature is maintained for a specific period of time. 4. An operating control apparatus of a gasification-melting furnace (3,4) for controlling the operation of said gasification-melting furnace (3,4) provided with a gasification furnace (3) for gasifying waste material Inlet, a melting furnace (4) configured to burn combustible constituents contained in pyrolysis gas produced in said gasification furnace (3) and introduced into the melting furnace (4) and melting ash in the pyrolysis gas, and a burner (40) for auxiliary combustion provided in said melting furnace (4), said operating control apparatus comprising: a waste feeder (2) for loading the waste material into said gasification furnace (3); and a thermometer (46) for detecting the temperature inside said melting furnace (4) in the vicinity of said burner (40); the operation control apparatus being characterized because: The control apparatus additionally comprises: an oxygen analyzer (45) for detecting the concentration of oxygen in the gas fed from said gasification furnace (3) to said melting furnace (4); and a control system (50 for controlling the operation of said gasification furnace (3) based on the detection results of said thermometer (46) and said oxygen analyzer (45), including said control system (50): a burner controller (52) that produces a burner stop order signal to stop the operation of said burner (40) when a state of operation of said gasification melting furnace (3,4) satisfies a specific burner stop condition; a waste charge controller (54) that produces a load stop order signal to prevent said waste load from loading the waste material into said gasification furnace (3) at a point in time when the temperature detected by said thermometer it falls to a pre-established temperature of stopping the waste load after said burner (40) has stopped working; Y the burner controller (52) produces a burner reignition order signal to reignite said burner (40) at a point in time when the oxygen concentration detected by said oxygen analyzer (45) is increased to a predetermined concentration of reignition of the burner after said waste feeder (2) has stopped loading waste material. 5. The operation control apparatus of the gasification-melting furnace (3,4) as described in claim 4, wherein the burner controller (52) produces the burner reignition signal regardless of the concentration of oxygen at a point in time when the temperature detected by said thermometer (46) is increased to a preset temperature greater than the stopping temperature of the waste load after said burner (40) has stopped working. 6. The operation control apparatus of the gasification-melting furnace (3,4) as described in claim 4 or 5, wherein the burner stop condition includes that the temperature detected by said thermometer (46) or one of its moving average values has remained the same or higher than a pre-set temperature of the burner stop for a specific period of time.