JP2955436B2 - Method of detecting moisture content of garbage in garbage incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refuse incineration system in which a drying zone for drying the conveyed dust while transporting it and a combustion zone for conveying the dried refuse and burning it through a step. The present invention relates to a method for detecting the moisture content of refuse in a furnace.

[0002]

2. Description of the Related Art An incinerator of this kind is provided with a drying zone so that garbage containing water such as garbage is dried as much as possible and burns the garbage from the step to the combustion zone. Drying and burning are promoted by crushing.However, since the degree of drying of the garbage on the combustion zone has a significant effect on the incineration efficiency, the garbage in the drying zone or the combustion zone depends on the degree of garbage drying. It is necessary to adjust the conveying speed of the air and the supply amount of the combustion air. However, conventionally, it has been difficult to detect the property itself such as the water content of the garbage on the high-temperature drying zone. Therefore, the combustion temperature or the like in the combustion zone is detected to indirectly detect the water content of the garbage. Some estimated the properties of the garbage and others detected infrared energy emitted from the surface of the trash from above the drying zone (Japanese Patent Application No. Hei 4
-26342).

[0003]

However, in the above-described apparatus for detecting the combustion temperature and the like, the properties such as the water content of the garbage currently burning are estimated, and the water content and the like of the garbage conveyed thereafter are estimated. In the case of a sudden change in the quality of garbage, it is possible to appropriately adjust the garbage transport speed and the supply amount of combustion air in the drying zone and combustion zone. The incineration efficiency was sometimes reduced. In the case of detecting infrared energy radiated from the surface of the garbage from above the drying zone, even if the surface temperature can be detected, the water content inside the garbage conveyed with a thickness of about 1 m on the drying zone can be detected. The properties could not be accurately detected. An object of the present invention is to provide a method for detecting the water content of refuse in a refuse incinerator that can accurately detect the water content inside the refuse before the refuse is conveyed to the combustion zone.

[0004]

In order to achieve this object, a characteristic structure of the method for detecting the water content of refuse in a refuse incinerator according to the present invention is as follows. The point is that the temperature distribution in the thickness direction in the cross section caused by the fall is determined by detecting infrared energy radiated from the cross section, and the moisture content of the dust is estimated based on the temperature distribution. In the above configuration,
Infrared energy has a center wavelength of 3.9 μm.
Is preferred. In addition, the thickness in the cross section
The time when the temperature distribution in the direction of
Judging when it is time to drop into the combustion zone, the temperature distribution immediately after
By detecting, the temperature of the cross section after dust falls
It is more preferable to detect the following.

[0005]

[Function] Of the refuse on the drying zone, the fuel
Infrared radiated from the cross section caused by falling into the burnt zone
The temperature distribution in the thickness direction obtained by detecting the line energy is
Generally, as shown in FIG.
The lower the garbage, the higher the moisture content.
This is because it is larger than the water content of the garbage. Therefore, upward
From the degree to which the temperature drops from
The amount can be estimated.The infrared energy is 3.
A band having a center wavelength of 9 μm is preferable.
This is because CO, CO in the flame generated on the combustion zone
_Two , NOX, SOX, and H _Two Infrared energy by O
This is to avoid the energy absorption band. Therefore, 3.9
Measures infrared energy in the band centered at μm
Characteristic infrared radiation emitted from the combustion exhaust gas
Infrared ray only, avoiding the emission wavelength region and no emission of combustion exhaust gas
Radiation intensity can be measured. Also, in the cross section
The time when the temperature distribution in the thickness direction suddenly decreases
Judgment of the fall time to the combustion zone and the temperature distribution immediately after
Detecting the temperature of the cross section after the dust falls.
It is more preferable to detect the degree. This is garbage
The temperature of the cross section after falling of the combustion zone depends on the heat of combustion in the combustion zone.
This is because it will rise gradually. Therefore, the combustion of garbage
Determine the timing of falling to the burn zone, and the cross section after the dust falls
The temperature of the minute can be detected.

[0006]

According to the present invention, there is provided a method for detecting the water content of garbage in a refuse incinerator, which can accurately detect the water content inside the refuse before the refuse is conveyed to the combustion zone. As a result, it has become possible to improve the combustion efficiency of the incinerator by appropriately adjusting the conveying speed of the refuse in the drying zone and the combustion zone and the supply amount of the combustion air. The infrared energy is 3.9.
More accurate if the band is centered on μm
In addition, it is possible to detect even the moisture content inside the garbage.
You. Further, the temperature distribution in the thickness direction in the cross section is
The time when the garbage drops sharply is the time when the garbage falls into the combustion zone.
By detecting the temperature distribution immediately after
It detects the temperature of the cross section after dust falls.
If present, more precisely the step from the drying zone to the combustion zone
It is possible to grasp the surface temperature of the cut surface of garbage when falling
It is possible.

[0007]

Embodiments will be described below. As shown in FIG. 3, the refuse incinerator is provided with a hopper 3 for storing refuse, which is an incineration object, a combustion chamber 2 for incinerating refuse, an ash pit 4 for collecting incinerated ash, and the like. is there. The combustion chamber 2
Are a drying zone 6 for drying dust heated by a pusher 5 provided at a lower end portion of the hopper 3 and heating the dust to near an ignition point, a combustion zone 7 for burning dry dust, and a dust zone burned in the combustion zone 7. And the post-combustion zone 8 for incineration of ash are arranged stepwise from above to below. At the boundary between the drying zone 6 and the combustion zone 7 and at the boundary between the combustion zone 7 and the post-combustion zone 8, there are provided steps d1 and d2 of about 1 m. A stoker-type transfer means S is provided which slides the fire grate G obliquely up and down by hydraulic cylinders C1, C2 and C3 and transfers the dust to the ash pit 4 while stirring the dust. The pusher 5 pushes dust into the combustion chamber 2 by reciprocating drive by a hydraulic cylinder C4. The refuse incinerated in the post-combustion zone 8 falls into the ash extruder 10, and is conveyed and collected in the ash pit 4 by the ash conveyer 11. The combustion zone 7 is composed of two regions, a front combustion zone 7A and a rear combustion zone 7B. The refuse is mainly combusted in the front combustion zone 7A by a combustion control device described later, and then completely separated in the rear combustion zone 7B. It is controlled so as to burn. In the lower part of the combustion chamber 2, the heated air sent by the blower 16 is used as air for drying and combustion.
And a damper D for adjusting the supply amounts to the drying zone 6, the combustion zone 7, and the post-combustion zone 8, respectively.
Is provided. The combustion gas generated in the combustion chamber 2 is extracted from the combustion gas by the exhaust heat boiler 12 in the form of steam so as to be used as energy of the generator 13 and supplied to the outside of the plant. And harmful gases are removed and exhausted.

The combustion chamber 2 has a radiation temperature detecting means 1 for detecting the temperature of dust on the drying zone 6 and a furnace outlet temperature comprising a thermocouple for detecting the temperature of the combustion zone 7 in order to monitor the combustion state. Detecting means 15, pressure detecting means (not shown) for detecting the amount of combustion air, etc. are provided. The incinerator has input means 18A for inputting the various sensor detection values, and input data from input means 18A. Means 18B for evaluating the combustion state of the combustion chamber 2 on the basis of the evaluation results, the dust input speed by the pusher 5, the dust transfer speed by the stoker means S, the opening of the damper, etc. Combustion control means 18 for adjusting and maintaining a stable combustion state
C is provided with a combustion control device 18 equipped with a microcomputer equipped with C.

The radiation temperature detecting means 1 is mounted so as to face the drying zone 6 from a further downstream side of the post-combustion zone 8 and detects black body radiation energy as shown in FIG. As shown in FIG. 1 and FIG.
CO, CO ₂ , NOX, SOX in the flame generated above
Furthermore in order to avoid infrared energy absorption bands due to H ₂ O, and the infrared camera 1a whose wavelength is provided about 3.9 (3.6 to 4) [mu] m filter, the image processing for analyzing the detected image by the infrared camera 1a The temperature distribution in the thickness direction of a cross section generated by dropping from the step portion d1 to the combustion zone 7 among the garbage having a thickness of about 1 m deposited on the drying zone 6 To detect.
More specifically, since the temperature of the cross section after the fall of the dust gradually increases due to the combustion heat in the combustion zone 7, the image processing unit 1b determines that the temperature detected by the radiation temperature detection unit 1 at the cross section is lower. The time when the combustion zone 7 suddenly drops
Then, the temperature distribution immediately after that is determined. As shown in FIG. 2, the temperature distribution is distributed so as to gradually decrease from above to below the cross section.
The water content of the garbage is estimated based on the degree. In other words, if the moisture content of the dust is high, the drying in the drying zone 6 is insufficient and the temperature below the cross-sectional portion is low. If the moisture content of the dust is low, the drying in the drying zone 6 is sufficient and the cross-section is insufficient. Paying attention to the fact that the temperature below the portion does not decrease so much, the moisture content of the dust is estimated based on the degree of the temperature gradient between the upper portion and the lower portion and the thickness of the dust.

When the radiant temperature detecting means 1 determines that the water content of the dust is large, the combustion control device 18 adjusts the opening of the damper D corresponding to the drying zone 6 to a large value to dry the dust. The transport speed in the combustion zone 7 is reduced to promote the combustion in the combustion zone 7 while promoting the combustion in the combustion zone 7, and the amount of refuse introduced by the pusher 5 and the transport amount in the drying zone 6 are reduced. If the temperature detection means 1 determines that the water content of the dust is small, the opening of the damper D corresponding to the drying zone 6 is maintained at the current level or slightly reduced to further promote the combustion in the combustion zone 7. The transport speed in the combustion zone 7 is increased, and the amount of dust input by the pusher 5 and the transport amount of the drying zone 6 are increased.

Another embodiment will be described below. The combustion control executed by the combustion control device 18 based on the detection result of the radiation temperature detecting means 1 described in the previous embodiment is not limited to the above-described one, and the thickness of the dust on the drying zone 6 and
Appropriate control can be performed based on detection information from another temperature sensor or the like.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a main part.

FIG. 2 is a temperature distribution diagram of a cross-sectional portion.

FIG. 3 is a schematic configuration diagram of an incinerator.

FIG. 4 is a wavelength characteristic diagram of black body radiation energy.

FIG. 5 is a characteristic diagram of the transmittance of the atmosphere.

[Explanation of symbols]

 6 Dry zone 7 Combustion zone d1 Step

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F23G 5/50

Claims (3)

(57) [Claims] 1. A drying zone (6) for drying while transporting input dust and a combustion zone (7) for burning while transporting the dried dust are connected via a step (d1). A method for detecting the water content of garbage in a garbage incinerator, wherein the step portion (d1) of the trash on the drying zone (6)
The temperature distribution in the thickness direction in the cross-section caused by falling from the surface to the combustion zone (7) is determined by detecting the infrared energy radiated from the cross-section, and the moisture content of the dust is estimated based on the temperature distribution. A method for detecting the water content of garbage in garbage incinerators. 2. The infrared energy of 3.9 μm
2. The incineration of garbage according to claim 1, wherein the garbage is in a band having a center wavelength.
A method for detecting the water content of refuse in a furnace. 3. A temperature component in a thickness direction at the cross section.
During the period when the cloth suddenly drops, the garbage falls into the combustion zone.
Judging the time and detecting the temperature distribution immediately after
The temperature of the cross section after the dust falls
Item 1. Method for detecting water content of garbage in garbage incinerator according to item 1 or 2.
Law.