JP4064314B2 - Waste layer high level measuring device in waste melting furnace - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for measuring the level of waste in a waste melting furnace for measuring the level of waste in a furnace in a waste melting furnace for melting waste by microwaves.
[0002]
[Prior art]
Waste includes municipal waste that is general waste, various industrial wastes, intermediate treatment products obtained by drying, incineration, crushing treatment, etc., incineration ash, and earth and sand that has been dug up again after landfill treatment. There is landfill waste or sludge containing waste, and as a treatment method for waste such as general waste and various industrial waste, the waste is dried / preheated, pyrolyzed in a shaft furnace type pyrolysis melting furnace, There is a waste melting treatment method that burns and melts and takes out as slag and metal.
[0003]
In the waste melting process, the height of waste in the furnace is measured, the height of the waste in the furnace is grasped, and the melting furnace is operated according to the height of the waste.
[0004]
As a means for measuring the surface height of the waste in the furnace, Patent Document 1 and Patent Document 2 describe a layer height level measurement in which the layer height level of the waste is measured by the reflected wave of the microwave transmitted by the microwave transmitting / receiving device. An apparatus is described. Like the conventional microwave transmission / reception apparatus shown in FIG. 2 (a), the waste layer high level measuring device in the waste melting furnace described in Patent Document 2 is fixed to the opening in the upper part of the waste melting furnace. A microwave transmitting / receiving device for measuring the layer height level of waste by a reflected wave of microwaves is provided on the upper part of the cylindrical body of the layer height level measuring device.
[0005]
[Patent Document 1]
JP-A-9-89632 [0006]
[Patent Document 2]
JP 2000-304233 A
[Problems to be solved by the invention]
The conventional microwave transmission / reception apparatus is installed on the center line of the furnace body of the melting furnace. FIG. 2B is a graph showing the relationship between the conventional microwave reflection intensity and the layer height level. Since the layer height level measuring device 4 provided with the microwave transmitting / receiving device 5 is installed on the center line 6 of the furnace body at the top of the waste melting furnace 1, the microwave hits the wall of the inner cylinder 3 and has a reflection intensity. A constant fixed reflected wave peak 7 appears, and a waste level reflected wave peak 8 appears in the vicinity thereof. However, when the level of the waste surface fluctuates, the peak 8 of the reflected wave at the waste level is affected by noise near the peak 7 of the fixed reflected wave, and the peak 8 of the reflected wave at the waste level does not appear clearly. In some cases, the waste level could not be measured.
[0008]
Accordingly, the present invention provides a layer height level measuring apparatus equipped with a microwave transmitting / receiving device capable of accurately measuring the layer height level of waste due to microwaves without the influence of noise in a waste melting furnace. Is.
[0009]
[Means for Solving the Problems]
The waste layer high level measuring device of the present invention is a microwave transmitting / receiving device for measuring a waste layer high level by a reflected wave of microwaves at a position shifted from the center line of the furnace body at the top of the waste melting furnace. The waste layer high level measuring device is provided, and the microwave irradiation angle of the microwave transmitting / receiving device is inclined by 3 to 10 ° with respect to the center line of the furnace body.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1A is a side view showing the arrangement of the microwave transmitting / receiving apparatus of the present invention, FIG. 1B is a plan view thereof, and FIG. 1C is a graph showing the relationship between distance and reflection intensity.
[0011]
1 (a) and 1 (b), an inner cylinder 3 for guiding a charge 2, such as waste, coke, and auxiliary materials charged from the top, into the furnace is provided in the top of the waste melting furnace 1. Has been placed.
[0012]
At the top of the waste melting furnace 1, a layer height level measuring device 4 having a microwave transmitting / receiving device 5 is arranged. The layer height level measuring device 4 is arranged at a position where the microwave transmitting / receiving device 5 deviates from the center line 6 of the furnace body.
[0013]
The microwave transmission / reception device 5 determines the installation location of the layer high level measurement device 4 so that the angle (θ) is 3 to 10 ° with respect to the center line 6 of the furnace body. Thus, it was found that the peak of the reflection intensity at the layer high level appears clearly.
[0014]
In FIG. 1A, when the distance shifted from the center line 6 of the furnace body is X, and the lower end of the inner cylinder 3 is L,
From X / L = tan θ,
X = L × tan θ,
Since θ = 3 to 10 °,
tan θ = 0.0524 to 0.176
Then, the distance X deviated from the center line 6 of the furnace body is set, and the layer height level measuring device 4 is arranged.
[0015]
By disposing the layer height level measuring device 4 at a distance X deviated from the center line 6 of the furnace body, the microwave reflected from the wall of the cylinder 3 is dispersed, and the peak of the fixed reflection intensity 7 is lowered. The peak 8 of the high level reflection intensity appears clearly larger than the fixed reflection intensity 7, and the layer height level can be accurately grasped.
[0016]
The diameter of the inner cylinder targeted by the present invention is a melting furnace provided with an inner cylinder having a diameter that reflects the microwave to the inner cylinder wall. That is, in FIG. 1A, when the diameter of the inner cylinder 3 is a,
From tan θ = (a / 2) / L,
a / 2 = L × tan θ
a = 2L × tan θ.
[0017]
Therefore, an inner cylinder having a diameter that is twice or more the irradiation angle θ is excluded.
[0018]
【Example】
As a result of measuring the layer height level at L = 6000 mm, a = 2100 mm, X = 650 mm, and θ = 7 °, the micro-reflection reflected from the wall of the cylinder 3 as shown in the reflection intensity graph of FIG. The peak of the fixed reflection intensity 7 of the wave was lowered, and the peak 8 of the reflection intensity at the layer high level appeared more clearly than the fixed reflection intensity 7, so that the layer height level could be measured accurately.
[0019]
【The invention's effect】
In the present invention, the layer height level measuring device is disposed at a position shifted from the center line of the furnace body, and the microwave irradiation angle of the microwave transmitting / receiving device is inclined by 3 to 10 ° with respect to the center line of the furnace body. Since the reflection intensity of the fixed wave is lower than the reflection intensity peak of the layer height level, the reflection intensity peak of the layer high level can be clarified, so the layer height level can be accurately grasped and the layer height situation can be determined Thus, it is possible to stably operate the melting furnace.
[Brief description of the drawings]
FIG. 1A is a side view showing the arrangement of a microwave transmitting / receiving apparatus of the present invention, FIG. 1B is a plan view thereof, and FIG. 1C is a graph showing the relationship between distance and reflection intensity.
FIG. 2A is a diagram showing the arrangement of a conventional microwave transceiver, and FIG. 2B is a graph showing the relationship between the reflection intensity of a conventional microwave and the layer height level.
[Explanation of symbols]
1: Waste melting furnace 2: Charge 3: Inner cylinder 4: Layer high level measuring device 5: Microwave transmitter / receiver 6: Center line 7 of furnace body: Fixed reflection intensity 8: Peak of reflection intensity at the layer high level

Claims (1)

At the top of the waste melting furnace, a waste layer high level measuring device having a microwave transmitting / receiving device that measures the layer height level of the waste by a reflected wave of microwaves is provided at a position shifted from the center line of the furnace body, An apparatus for measuring a high level of a waste layer in a waste melting furnace, characterized in that the microwave irradiation angle of the microwave transmitting / receiving apparatus is inclined by 3 to 10 ° with respect to the center line of the furnace body.

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