JP2785414B2 - Detection method of supply interruption of incinerated material in fluidized bed incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a fluidized bed incinerator for incinerating incinerators such as municipal garbage, whether or not supply of the incinerator into the incinerator has been interrupted. And a method for detecting

[Prior Art] This kind of fluidized bed incinerator generally uses a fluid medium S such as sand stored in a furnace body 1, that is, sand in a furnace 1 a, as shown in FIG. Primary air for combustion is ejected from a plurality of diffuser tubes 2 arranged in a plane to fluidize the air. On the other hand, the incinerated material G to be incinerated is dropped from the conveyor 3 into the hopper 4 and then screwed into the screw conveyor 5. Then, the material to be incinerated G is charged onto the fluid medium S through the charging chute 6 to fluidize the material to be incinerated G together with the fluid medium S.

The incinerated material G comes into contact with the flowing medium S and flows with the flowing medium S to be dried, thermally decomposed, and burned (primary combustion). The exhaust gas after the secondary combustion is guided to the outside of the furnace body 1 through the exhaust port 7a of the furnace body 1 and is recovered or cooled by the incineration treatment (secondary combustion).
Released into the atmosphere. Further, the non-combustible material G ₀ mixed in the incinerated material G is discharged out of the furnace body 1 from the discharge port 7b.

By the way, in the fluidized bed incinerator as described above,
Since the fluid medium S is heated by the burning of the incinerated material G, if the supply of the incinerated material G is interrupted, the heated state of the fluid medium S is not maintained. For this reason, it is possible to reduce the supply of the secondary air to an allowable minimum amount of the secondary air supply mechanism or perform operations such as adjusting the ejection amount of the primary air to a necessary minimum to achieve stable operation. Desired.

Therefore, conventionally, a camera 8 that monitors the supply state of the incinerated material G into the furnace 1a monitors the state of the incinerated material G, and also receives information from a level detection device 9 that detects the level of the incinerated material G in the hopper 4. Based on the above, it is determined whether or not the supply of the incinerated material G to the furnace interior 1a has been interrupted. If the supply has been interrupted, the above operation is performed.

[Problems to be Solved by the Invention] In the method of detecting the interruption of the incinerated material G, the former is a monitor of the inside of the furnace 1a by the camera 8, so that the method is based on human visual judgment and is continuous. Monitoring is difficult, and in the latter case, the level detecting device 9 determines that the incinerated material G in the hopper 4 is gone, and the supply of the incinerated material G to the furnace 1a is actually interrupted. It was not possible to know exactly when to do it.

The present invention has been made in view of the above-mentioned problems of the related art, and accurately grasps interruption of supply of incinerators in a fluidized bed incinerator to supply incinerators that can be operated stably. It is an object to provide an interruption detection method.

Means for Solving the Problems In order to achieve the above object, a method for detecting a supply interruption of an incinerated object in a fluidized-bed incinerator according to the present invention is to discharge primary air for combustion from an air diffuser disposed in the furnace. In addition, the incineration material is supplied by a transport device onto a heated and fluidized medium stored in a furnace, so that the incinerated material is primary-burned while the incinerated material is fluidized together with the fluidized medium. In a fluidized bed incinerator, in which the combustible gas generated at the time of combustion is incinerated by secondary combustion with secondary air for combustion, the heat radiation energy generated at the time of the primary combustion is measured, and the measured value is a predetermined value. Since the supply of the incineration material into the furnace was interrupted due to the decrease below the set value, the transfer speed of the transfer device was increased, and the supply amount of the primary combustion air to the furnace was reduced to a minimum. Reduced to If the measured value is higher than the set value, the transfer speed of the transfer device is reduced, and the primary air for combustion and combustion are reduced. It is characterized in that the amount of secondary air for use supplied to the furnace is increased.

Further, another invention measures the heat radiation energy generated at the time of the primary combustion, measures the pressure in the furnace, and compares these two measurement signals. It is characterized in that it is detected whether or not the supply has been interrupted.

[Operation] According to the method for detecting interruption of supply of incinerated material in a fluidized bed incinerator according to the present invention, (1) the measured value of thermal radiation energy generated at the time of primary combustion falls below a predetermined set value; Thus, it is determined that the supply of the incineration material into the furnace has been interrupted.

(2) Alternatively, the measured signals of the heat radiation energy and the furnace pressure are compared after being subjected to appropriate pretreatment as necessary.
The difference (furnace pressure) − (thermal radiation energy) = Δn is obtained. If this value is larger than a predetermined set value, it is detected that the supply of the incineration material has been interrupted.

By the methods (1) and (2), the interruption of the supply of the incinerated material into the furnace is accurately detected.

Embodiment An embodiment of the present invention will be described below with reference to FIG. This embodiment is based on claim 1 of the present invention.

FIG. 1 is an overall schematic view of a fluidized bed incinerator apparatus according to the present embodiment, and the apparatus of the present invention described in the above item 1 can be carried out by this apparatus.

First, this device will be described. In the figure, reference numeral 11 denotes a furnace body.
Inside the furnace 11, that is, inside the furnace 11a, a fluid medium S such as sand is appropriately stored. The fluid medium S is kept at a high temperature by the combustion of the incineration material G during the steady operation.

The furnace body 11, the fluid medium inlet 12 for introducing the object to be incinerated G on S, the discharge port 13a for discharging the incombustible material G ₀ with the fluidized medium S contained in the incinerated G, An exhaust port 13b for exhausting exhaust gas after combustion is provided.

A screw conveyor 15 and an incineration object G are connected to the screw conveyor 15 through the input chute 14 through the input chute 14.
A hopper 16 for feeding
A conveyer 17 for dropping the incinerated material G is provided in the inside, and by injecting the incinerated material G into the hopper 16 from the conveyer 17, the conveyed material G is transferred from the inlet 12 through the screw conveyor 15 and the charging chute 14. The incineration material G is configured to fall on the fluid medium S in the furnace 1a and supplied. The driving speed of the screw conveyor 15 is controlled by a screw conveyor speed control device 18.

At the bottom of the furnace 11a, a plurality of air diffusers 19 formed with a number of nozzles (not shown) that open laterally are provided with a fluid medium S.
Are arranged in parallel at equal intervals. Primary air supplied from a primary combustion air (hereinafter abbreviated as “primary air”) supply mechanism 20 provided outside the furnace body 11 is ejected from the nozzles of the diffuser pipes 19, and the primary air causes the fluid medium S to flow. The incinerated material G supplied on the fluid medium S is fluidized, and the incinerated material G is dried, thermally decomposed, and burned, that is, primary-burns.

The primary air supply mechanism 20 includes a primary air blower 21,
It is composed of a damper 22 for adjusting the flow rate of primary air blown from the primary air blower 21, and a primary air flow control device 23 for controlling the opening degree of the damper 22. The amount of primary air ejected from the diffuser pipe 19 by the primary air supply mechanism 20 depends on the temperature of the fluid medium S and the fluid medium S based on the superficial velocity required for fluidizing the fluid medium S.
It is determined in consideration of the operating conditions such as changes in the quality of the sand (sand if sand).

The furnace body 11 is provided with a secondary air for combustion (hereinafter abbreviated as secondary air) supply port 24. This secondary air supply port 24
From the secondary air supply mechanism 25 provided outside the furnace body 11.
Secondary air supplied from above is ejected above the fluid medium S,
This secondary air is mixed with combustible gas generated from the incinerated material G burned as described above, and burned (secondary combustion).
Let it.

In addition, the secondary air supply mechanism 25 is the primary air supply mechanism.
As with 20, the secondary air blower 26 and this secondary air blower
The damper 27 includes a damper 27 for adjusting the flow rate of the secondary air blown from 26, and a secondary air flow control device 28 for controlling the degree of opening of the damper 27.

In addition, the secondary air supply port 24 and the secondary air supply mechanism 25
Although one set is shown in the drawing, a plurality of sets may be provided so that the respective flow rates can be adjusted so as to obtain optimum secondary combustion.

An exhaust passage 30 communicating with the chimney 29 is connected to the exhaust port 13b, and the exhaust gas in the furnace 11a is passed through the exhaust passage 30 by the induced exhaust fan 31 installed in the middle of the exhaust passage 30 through the chimney 29.
From the atmosphere.

In the middle of the exhaust passage 30, a dust sedimentation chamber 32 for sedimenting and removing dust in the exhaust gas, an exhaust heat boiler 33 for recovering heat of the exhaust gas, and a dust Precipitator 34 for electrically adsorbing and removing dust
Are provided respectively. Further, in the furnace 11a, a nozzle 35 for spraying water to the fluid medium S is installed in order to keep the temperature of the fluid medium S below a specified value. The nozzle 35 is connected to a water supply pipe 36 provided with an on-off valve 36a on the way.

The inlet of the electrostatic precipitator 34, the O ₂ concentration analyzer 37 is provided for analyzing O ₂ concentration in the exhaust gas.

Further, the furnace body 11 is provided with a thermal radiation thermometer 38 as a thermal radiation energy measuring device for primary combustion.

When the heat radiation thermometer 38 indicates a high temperature, for example, it is determined that the incineration material G is supplied in a large amount as described above and explosive primary combustion has occurred. It is determined that the supply amount is small or interrupted.

The measurement signal of the thermal radiation thermometer 38 is sent to the control device 39,
If the signal (measured value) is lower than a predetermined set value, it is detected that the supply of the incineration material G has been interrupted, and the control device 39 increases the transport speed of the screw conveyor 15 via the screw conveyor control device 18, The on-off valve 36a of the pipe 36 is closed.

Further, a signal is sent to the primary air flow control device 23 and the secondary air flow control device 28, and the damper of the primary air supply mechanism 20 is
22 is closed to minimize the primary air flow from the air diffuser 19, and the damper 27 of the secondary air supply mechanism 25 is closed to the minimum allowable opening to reduce the supply of secondary air to the furnace 11a. .

Further, when the measurement signal of the thermal radiation thermometer 38 becomes higher than the set value and returns to the original state, the incineration material G is supplied to the furnace interior 11a, and it is determined that the normal operation state has been reached. Return to the original state by operation.

As described above, according to the fluidized bed incinerator, when the supply of the incineration material G is interrupted, the measured value becomes equal to or less than the predetermined set value based on the measured value of the thermal radiation thermometer 38. Then, the control device 39 increases the transport speed of the screw conveyor 18 to promptly supply the incinerated material G, and stops the supply of water from the nozzle 35 to stop the fluid medium S
Is prevented from lowering. Also, the supply of primary air is minimized and the supply of secondary air is reduced.

As a result, stable operation can be achieved with almost no hindrance such as a rapid decrease in the amount of generated steam due to interruption of the supply of the incineration material G and an excessive decrease in the temperature of the fluid medium S.

Therefore, according to the method of detecting whether or not the supply of the incineration material G has been interrupted based on the measured value of the thermal radiation thermometer 38 of the present embodiment, the time of the interruption can be accurately grasped, and the present embodiment can be performed. As in the example, the influence can be suppressed as much as possible even when the supply is interrupted based on the measurement signal, so that stable operation can be achieved.

Next, another embodiment of the present invention will be described with reference to FIGS. This embodiment is based on Claim 2 of the present invention, and is obtained by adding new components to the fluidized bed incinerator of the previous embodiment. The same reference numerals are given to the same components and the description thereof is omitted.

In addition to the thermal radiation thermometer 38, the furnace body 11
An in-furnace pressure measuring device 40 for measuring a change in pressure in a is installed. Then, using the in-furnace pressure measuring device 40 as an index, the pressure of the in-furnace 11a is maintained at a substantially constant predetermined value by a separate control device. By the way, the pressure in the furnace 11a is reduced when the supply of the incineration material G is small or interrupted, the state of primary combustion is reduced, and the pressure in the furnace 1a is also reduced accordingly. The pressure of 1a is increased to a predetermined value.

The measurement signals from the thermal radiation thermometer 38 and the furnace pressure measuring device 40 are sent to a signal calculator 41, respectively. Signal calculator 41
Calculates the difference (furnace pressure)-(thermal radiation energy) = ｎn after comparing both signals after performing appropriate preprocessing if necessary.

This value Δn is sent to the discriminator 42, where it is determined whether or not Δn is larger than a predetermined set value. FIG. 3 shows the flow up to this point.

Since the pressure in the furnace 11a is kept substantially constant by the separate control device as described above, as Δn is larger, the heat radiation energy is lower, that is, the primary combustion state is extremely low, or the incineration It indicates that the supply of G is interrupted, and the predetermined set value is determined accordingly.

Next, Δn is sent to the control device 43, and when Δn is larger than the set value, the control device 43 determines that the supply of the incineration material G has been interrupted, and performs the operation described in the above embodiment. When Δn becomes smaller than the set value, the above operation is performed.

Figure 4 shows an example of a change in the measured signal of the fluidized bed usually heat radiation thermometer 38 and the inner pressure measuring device 40 during the operation of the incinerator, and O ₂ concentration analyzer 37 (O ₂ The measurement signal of the concentration analyzer 37 indicates the O ₂ concentration in the furnace 11a by correcting the detection delay).

According to this, it is understood that there is a positive correlation between the signal of the thermal radiation thermometer 38 and the pressure in the furnace 11a, and a negative correlation with the O ₂ concentration in the furnace 11a.

FIG. 5 shows changes in the furnace temperature and the furnace pressure when the supply of the incineration material G is interrupted. according to this,
As the temperature of the primary combustion decreases due to the interruption of the supply of the incineration material G, the pressure in the furnace once decreases, but as described above, it is increased to a predetermined value by a separate control device and then kept substantially constant. For this reason, the correlation between the two is lost, and a difference occurs in the measurement signal. That is, the measurement signal of the furnace pressure increases. This difference is the above-mentioned Δn, and when this Δn exceeds the set value, the discriminator 42 sends a supply interruption signal of the incineration material G to the control device 43.

Therefore, according to this method, even if the supply of the incineration material G is temporarily interrupted and the measured value of the thermal radiation thermometer 38 decreases,
When the incinerated material G is supplied again soon, the pressure signal in the furnace is temporarily reduced together with the interruption of the incinerated material G, so that the set value of the thermal radiation thermometer 38 does not exceed the set value of Δn and the original value is restored. Returns to the value. For this reason, when the supply interruption period of the incineration material G is very short, the supply of the incineration material G is not interrupted, and when the control described later is performed, a more stable operation can be performed.

According to the fluidized bed incinerator apparatus, as in the previous embodiment, when the supply of the incinerated material G is interrupted, the discriminator 42 is used.
And the control device 43 increases the transport speed of the screw conveyor 18 to promptly supply the incinerated material G, and stops the supply of water from the nozzle 35 to reduce the temperature of the furnace 11a. Reduction is prevented. Also, the supply of primary air is minimized and the supply of secondary air is reduced. As a result, stable operation can be performed with almost no trouble such as a rapid decrease in the amount of generated steam due to the interruption of the supply of the incineration material G and an excessive decrease in temperature of the fluid medium S.

As described above, according to the method of comparing the measurement signal of the thermal radiation thermometer 38 with the measurement signal of the in-furnace pressure gauge 40, and detecting whether or not the supply of the incineration material G has been interrupted based on the difference. ,
The interruption time can be accurately grasped, and stable operation can be achieved even when the supply is interrupted based on the measurement signal as in the present embodiment.

[Effects of the Invention] The present invention is configured as described above, and has the following effects.

According to the first aspect of the invention, it is possible to accurately grasp the interruption of the supply of the incineration material, and almost causes troubles such as a rapid decrease in the amount of generated steam due to the interruption of the supply of the incineration material and an excessive decrease in the temperature of the fluidized medium. And stable operation becomes possible.

The invention according to claim 2 does not consider the supply of the incinerated material to be interrupted when the period of the supply of the incinerated material is extremely short,
More stable operation can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic overall view of a fluidized bed incinerator apparatus suitable for carrying out an embodiment of the present invention, and FIGS. 2 to 5 are views for explaining another embodiment of the present invention. FIG. 2 is a schematic general view of a fluidized bed incinerator suitable for carrying out the embodiment, FIG. 3 is a flowchart showing a part of a control method, and FIG. 4 is a heat radiation temperature during normal operation. Is a graph showing the relationship between the measurement signal of the pressure gauge, the furnace pressure measuring instrument and the O ₂ concentration analyzer and the time, and FIG. 5 shows the measurement signal of the heat radiation thermometer and the furnace pressure measuring instrument when the supply of the incineration material is interrupted. FIG. 6 is a side sectional view of a fluidized bed incinerator for explaining a conventional method of interrupting the supply of the incineration material. 11a: inside the furnace, 19: diffuser tube, 38: thermal radiation thermometer, 3
9, 43: Control device, 40: Furnace pressure measuring device, G: Incinerated material, S: Fluid medium.

Claims (2)

(57) [Claims] The present invention relates to a fluidized medium, wherein primary air for combustion is blown out from a diffuser pipe provided in a furnace, and a substance to be incinerated is supplied by a transfer device onto a fluidized medium stored and heated in the furnace. The fluidized bed incinerator, in which the incinerated material is primarily burned while fluidizing the incinerated material, and the combustible gas generated at that time is subjected to incineration treatment by secondary combustion with secondary air for combustion, The thermal radiation energy generated during the combustion is measured, and when the measured value falls below a predetermined set value, it is determined that the supply of the incinerator into the furnace has been interrupted, and the transport speed of the transport device is determined. And the supply amount of the primary air for combustion into the furnace is reduced to a necessary minimum and the supply amount of the secondary air for combustion into the furnace is reduced, so that the measured value becomes higher than the set value. The transfer device A method for detecting a supply interruption of an incinerator in a fluidized bed incinerator, wherein the supply speed of the primary air for combustion and the secondary air for combustion are increased into the furnace while reducing the conveying speed of the apparatus. 2. The method for detecting interruption of supply of an incinerated material in a fluidized bed incinerator according to claim 1, wherein the heat radiation energy generated during the primary combustion is measured and the pressure in the furnace is measured. A method of detecting the interruption of the supply of the incinerator in the fluidized bed incinerator, which detects whether or not the supply of the incinerator into the furnace is interrupted by comparing these two measurement signals.