JPH11141842A - Method and device of monitoring condition inside fluidized furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure the amount of the incombustible substances which exist in a fluidized bed. SOLUTION: A vibration of a fluidized bed 6 is detected by a vibration sensor 10 which is set in a furnace, and the frequency component by the vibration of a fluidizing medium 5, a furnace body 1, a blower 4, etc., is eliminated through a filter 11. The amount of the incombustible substances inside the fluidized bed is grasped from the obtained vibration strength of the incombustible substances. The vibration sensor 10 is preferable to be set at the ceiling part of a pressure equalizing chamber 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for monitoring a situation inside a fluidized-bed furnace used for incinerating waste such as municipal solid waste and sewage sludge.

[0002]

2. Description of the Related Art In order to stably operate a fluidized-bed furnace, it is necessary to monitor many physical quantities such as temperature, pressure, amount of a fluidized medium, oxygen concentration, etc. inside the furnace. I have. However, non-combustible materials such as steel cans, aluminum cans, and stones may be contained in the waste such as municipal solid waste put into the fluidized-bed furnace. So far, there has been no known means for determining the amount of incombustibles inside the fluidized bed, despite having a negative effect on the stability of the fluidized bed. For this reason, incombustibles are separated from the fluidized bed only at a constant pace, and the calorie of the fluidized bed may be unnecessarily impaired. There was a possibility that the stability of the polymer was impaired.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems and provides a method and an apparatus for monitoring the situation inside a fluidized furnace, which can measure the amount of incombustible substances which hinder the stability of a fluidized bed. It was done to do so.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for monitoring the situation inside a fluidized-bed furnace according to the present invention detects vibrations of a fluidized bed with a vibration sensor and uses the detected vibration waveform as a filter. The filter removes frequency components caused by vibrations of the fluidized medium, the furnace body, the blower, etc., and determines the amount of incombustibles inside the fluidized bed based on the vibration waveform and the intensity passing through the filter. In addition, the condition monitoring device inside the fluidized-bed furnace according to the present invention includes a vibration sensor that detects vibration of the fluidized bed inside the fluidized-bed furnace, and detects a fluid medium, a furnace body, and a blower from a vibration waveform obtained by the vibration sensor. And a filter for removing a frequency component due to vibrations such as described above. Preferably, the vibration sensor is installed on the ceiling of the pressure equalizing chamber.

According to the present invention, the amount of incombustibles inside the fluidized bed can be grasped by passing the vibration waveform of the fluidized bed obtained by the vibration sensor through a filter and analyzing it.
For this reason, when the amount of incombustibles increases, the stability of the fluidized bed can be ensured by increasing the separation speed of incombustibles from the fluidized bed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. In FIG. 1, reference numeral 1 denotes a furnace body of a fluidized-bed furnace, and reference numeral 2 denotes a number of dispersion nozzles provided on the bottom surface thereof. Reference numeral 3 denotes a pressure equalizing chamber provided at a lower portion of the furnace body, and air for flowing is supplied by a blower 4. The air for flow supplied to the pressure equalizing chamber 3 is jetted into the furnace through the dispersion nozzle 2,
A fluidized medium 6 such as silica sand is caused to flow to form a fluidized bed 6. The input waste is incinerated in a very short time in contact with the high temperature fluid medium 5.

As described above, non-combustible materials such as steel cans, aluminum cans, and stones are often contained in wastes such as municipal waste, but these are not incinerated even when put into a furnace. It is accumulated in the fluidized bed 6. Therefore, the floor surface of the furnace body 1 is inclined as shown in the figure, and the fluid medium 5 is drawn out from the fluid medium discharge hole 7 at the lower end thereof by a screw conveyor 8, and the fluid medium 5 and the incombustible material are separated by a separator 9. Then, the fluid medium 5 is returned to the furnace. The above configuration is the same as the conventional one.

However, in the present invention, the vibration sensor 10 for detecting the vibration of the fluidized bed 6 is provided in the furnace. Although the installation position is not particularly limited, in this embodiment, a plurality of vibration sensors 10 are arranged on the ceiling of the pressure equalizing chamber 3 below the dispersion nozzle 2 having a relatively low temperature. When the vibration sensor 10 is installed at this position, there is an advantage that cooling can always be performed by the air for fluidization and vibration of the fluidized bed 6 can be easily taken out accurately. As the vibration sensor 10,
A commercially available eddy current type micro displacement meter, induced current type micro displacement meter, optical type micro displacement meter, or the like can be used.

A frequency analysis of the vibration waveform taken out by these vibration sensors 10 reveals that the vibration waveform contains frequency components as shown in FIG. 2, for example. However, the vibration waveform includes a vibration waveform A of the furnace body 1, a vibration waveform B of the blower 4, a vibration waveform C of the fluid medium 5, and the like. Therefore, the vibration waveform obtained by the vibration sensor 10 is passed through a filter 11 capable of removing these vibration waveforms A to C to remove their frequency components. As a result, the vibration waveform that has passed through the filter 11 is substantially only the vibration waveform D of the non-combustible material inside the fluidized bed 6 as shown in FIG. Moreover, since it has been confirmed that the vibration intensity changes depending on the amount of incombustible substances, the amount of incombustible substances can be grasped from the vibration intensity.

[0010] Thus, according to the present invention, the fluidized bed 6
It is possible to accurately monitor the amount of incombustibles inside the vehicle. For this reason, when the amount of incombustibles increases, the output of the screw conveyor 8 is increased to increase the amount of fluid medium 5 withdrawn,
A large amount of the fluid medium 5 may be sent by the separator 9 to remove incombustibles therein. As a result, the amount of incombustibles inside the fluidized bed 6 is always kept at a certain level or less, and the fluidized-bed furnace can be operated stably.

[0011]

As described above, according to the method and the apparatus for monitoring the condition inside the fluidized bed of the present invention, the steel can and the aluminum inside the fluidized bed are based on the vibration of the fluidized bed detected by the vibration sensor. It is possible to accurately monitor the amount of incombustibles such as cans and stones. For this reason, when the amount of incombustibles increases, the stability of the fluidized bed can be ensured by increasing the separation speed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a vibration waveform diagram of a fluidized bed.

FIG. 3 is a vibration waveform diagram after passing through a filter.

[Explanation of symbols]

1 furnace body, 2 dispersion nozzles, 3 pressure equalizing chamber, 4 blowers,
5 fluidized medium, 6 fluidized bed, 7 fluidized medium discharge holes, 8
Screw conveyor, 9 separator, 10 vibration sensor,
11 Filter

Claims (3)

[Claims] 1. A method for detecting the vibration of a fluidized bed by a vibration sensor, and passing the detected vibration waveform through a filter to obtain a fluid medium,
A method for monitoring the condition inside a fluidized bed, comprising: removing a frequency component caused by vibration of a furnace body, a blower, etc., and grasping an incombustible amount inside the fluidized bed from a vibration waveform and intensity passed through a filter. 2. A vibration sensor for detecting vibration of a fluidized bed is installed inside a fluidized furnace, and a frequency component due to vibration of a fluid medium, a furnace body, a blower, etc. is removed from a vibration waveform obtained by the vibration sensor. A condition monitoring device inside a fluidized-bed furnace, which is provided with a filter for performing the operation. 3. The condition monitoring device according to claim 2, wherein the vibration sensor is installed on a ceiling of the pressure equalizing chamber.