JP2003207382A - Method and device for measuring accumulated height of deposit in container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for accurately measuring the accumulated height of a deposit in a container even when an object flowing or is being scattered. <P>SOLUTION: An electromagnetic wave transmitter/receiver 7 installed on a furnace generates a microwave signal, transmits it to the inside of the furnace from a microwave antenna 8, and receives a reflection signal from an object (waste matters) in the furnace. The received signal is input to the electromagnetic wave transmitter/receiver 7 to generate and output a detection signal delayed in time according to a distance to the object in signal processing. A signal processor 9 calculates a measurement value representing the detection signal obtained through transmission/reception of the microwave, and further calculates an average of measurement values of the detection signals and outputs it as a measured height of an inner layer of the furnace. <P>COPYRIGHT: (C)2003,JPO

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 measuring the height of a deposit in a container housed and deposited in a container. Combustion furnaces that burn and burn, especially shaft-type combustion furnaces, and in particular, those that incinerate and melt wastes, especially in high-temperature gasification and melting furnaces, raw materials for wastes that are put into the furnace and incinerated and melted The present invention relates to a technique useful for measuring the inner layer height (level) of the furnace.

[0002]

2. Description of the Related Art As a technique for measuring the layer height in a furnace, there is a method called sounding, and an apparatus is commercially available. This is to detect the change in load due to the weight being connected to the tip of wire, chain, etc., the weight being lowered from the upper part of the furnace while measuring the load applied to the wire and chain, and the weight coming into contact with the raw material in the furnace. The height of the bed in the furnace is measured from the amount of descent of the weight when the load decreases or disappears.

Further, as a non-contact inner layer height measuring means, an electromagnetic wave (microwave) is projected from the upper part of the furnace to detect a reflection signal from a raw material in the furnace, and the time interval from the projection of the electromagnetic wave to the detection is detected in the furnace. There is a method of calculating the distance to the raw material and measuring the bed height in the furnace, and the device is commercially available.

[0004]

In the above-mentioned method called sounding, since detection is performed by lowering the weight, there is a problem that a constant time is required for measurement and continuous measurement cannot be performed. In addition, since the detection is performed by the fluctuation of the load, erroneous detection may occur when it contacts the furnace wall in the furnace, and further, when the raw material to be measured flows or scatters. In some cases, the weight intrudes into the raw material, making it impossible to accurately measure the layer height.

In the method for measuring the height of the inner layer of the furnace (microwave level meter) utilizing the electromagnetic wave, generally, the time until the reflection signal from the object is detected and the reflection signal is obtained, and the propagation speed of the microwave is measured from the object to the object. However, when the object is flowing or scattering, the reflected signal changes greatly with the flowing and scattering conditions, and multiple reflected signals are generated, so the accurate bed height is calculated. It may not be possible to measure.

The present invention has been made in view of the above circumstances, and even when an object flows or scatters,
An object of the present invention is to provide a method and an apparatus capable of accurately measuring the deposition height of deposits in a container.

[0007]

The first means for solving the above-mentioned problems is a method for measuring the deposition height of deposits in a container, in which electromagnetic waves are repeatedly projected from the top of the container to form the above-mentioned deposits. Detects the reflection signal from the object, calculates the distance to the deposit from the time interval from the projection of the electromagnetic wave to the detection,
In the method of measuring the deposition height from the distance, only the reflected signals obtained for one projection of electromagnetic waves having a signal intensity equal to or higher than a predetermined reference intensity are extracted, and each of them is extracted. The respective distances are calculated based on the signal, and the longest distance among them is used as the representative value for the projection of the electromagnetic wave, and the distance to the deposit is calculated by averaging the representative values obtained repeatedly, A deposition height measuring method for deposits in a container (claim 1), characterized in that the deposition height is measured from a distance.

According to this means, the sediment flows in the container,
It is effective when scattered. In this situation,
When electromagnetic waves (microwaves) are projected from above the container, a plurality of reflected signals from a plurality of flowing and scattering targets are obtained. The intensity of the reflected signal changes depending on the flow, shape, size, and density of scattered objects.

At this time, among the reflection signals obtained, the reflection signal farthest from the antenna passes through a plurality of targets in the container that flow and scatter, and is fixed below the flow and scatter layer. It is considered to be a reflection signal from a flow or scattered matter existing at a position close to the bed or the fixed bed. Therefore,
The distance value obtained by using this means can measure the level of the fixed layer existing below the flow and scattering layers.

Occasionally, even if a large amount of radio waves are reflected in the flowing and scattering layers and do not reach the fixed layer, this means performs a plurality of measurements and deposits based on the average value. Since the height is calculated, the height of the fixed layer can be accurately measured. In this means,
The reason why only the signal strength equal to or higher than the predetermined reference strength is extracted and used is to cut noise, and this is the same in other means.

A second means for solving the above problems is
A method for measuring the deposition height of a deposit in a container, wherein electromagnetic waves are repeatedly projected from the top of the container to detect a reflection signal from the deposit, and the deposit is detected from the time interval from the projection of the electromagnetic wave to the detection. In the method of calculating the distance to and measuring the deposition height from the distance, the reflected signal obtained for one electromagnetic wave projection has a signal intensity equal to or higher than a predetermined reference intensity. Extract only, calculate the distance based on each signal, and use the shortest distance among them as a representative value for the projection of the electromagnetic wave, and by averaging the representative values obtained repeatedly, Is calculated, and the height of deposition is measured from the distance. The method for measuring the height of deposition of deposits in a container (claim 2).

According to this means, the sediment flows in the container,
When scattered, it is effective in calculating the steady upper limit position of these fluidized beds. That is, when the deposit is flowing or scattering, the upper limit position can be calculated from the electromagnetic wave having the shortest measurement distance among the electromagnetic waves reflected from them. In this means, the one with the shortest measurement distance in each measurement is calculated, and the value is averaged to calculate the deposition height, so the steady upper limit position of the steady fluidized bed is calculated. be able to.

A third means for solving the above problems is
A method for measuring the deposition height of a deposit in a container, wherein electromagnetic waves are repeatedly projected from the top of the container to detect a reflection signal from the deposit, and the deposit is detected from the time interval from the projection of the electromagnetic wave to the detection. In the method of calculating the distance to and measuring the deposition height from the distance, the reflected signal obtained for one electromagnetic wave projection has a signal intensity equal to or higher than a predetermined reference intensity. , And the distance to the deposit by determining the reflection signal with the largest signal strength, calculating the distance based on the reflection signal, and using it as a representative value for the projection of the electromagnetic wave, and averaging the representative values obtained repeatedly. Is calculated, and the deposition height is measured from the distance, which is a deposition height measuring method for deposits in a container (claim 3).

Among the reflected signals from the sediment, the strongest one has a relatively large shape in the flowing and scattering layers,
Obtained from denser layers. Therefore, according to this means,
It is possible to measure the level of a layer having a relatively large shape and a high density in the fluidized and scattered layers.

A fourth means for solving the above-mentioned problems is as follows.
A method for measuring the deposition height of a deposit in a container, wherein electromagnetic waves are repeatedly projected from the top of the container to detect a reflection signal from the deposit, and the deposit is detected from the time interval from the projection of the electromagnetic wave to the detection. In the method of calculating the distance to, and measuring the deposition height from the distance, regarding a plurality of reflection signals obtained for the projection of electromagnetic waves from the top of the container, a plurality of pre-divided containers in the height direction of the container Counting the number of reflection signals reflected from the area, and having a signal strength equal to or higher than a predetermined reference strength, from the number of reflection signals in each area, determination of the flow state of the raw material in the container,
A method for measuring the height of deposits in a container (claim 4), characterized in that it has a process of performing at least one of determining the scattering state of the raw material and determining the reliability of the measurement of the layer height in the container.

The flow and scattering of the deposits in the container are severe,
When the density of scattered material in the vessel is high, the electromagnetic waves propagating in the furnace are reflected, scattered, and attenuated sequentially, so even if a reflected signal from scattered material in the upper part of the furnace is obtained, The reflected signal may not be obtained in some cases. Even in such a case, if the reflected signal is obtained, it is possible to perform the above-mentioned processing to calculate and output the level value, but it is not reliable as a measured value. Although the reliability of the measured values cannot be judged only by the output measured values, the multiple reflected signals obtained for the projection of electromagnetic waves are reflected from multiple regions in the height direction inside the pre-divided container. , And counting the number of reflection signals having a signal intensity equal to or higher than a predetermined reference intensity, and judging from the number of reflection signals in each region, the flow state of the raw material in the furnace, the scattering state in the furnace, and the inside of the furnace It is possible to judge the reliability of the measurement of the bed height. For example,
With respect to the upper and lower regions of the furnace body, the number of reflection signals existing in each region is counted. When the number of reflection signals of the upper part is larger than the number of reflection signals of the lower part, the scattering state in the furnace is It can be judged as intense. Also, in that case, the reflection and scattering of electromagnetic waves in the upper part of the furnace increase,
In the lower part of the furnace, electromagnetic waves may be attenuated and the reflected signal from the object in the lower part of the furnace may not be detected, and it is possible to determine that the reliability of the calculated level measurement value is reduced.

A fifth means for solving the above-mentioned problems is as follows.
First pseudo random signal generating means for generating a pseudo random signal; second pseudo random signal generating means for generating a pseudo random signal having the same signal pattern as the first pseudo random signal but a slightly different frequency; First multiplication means for multiplying the first and second pseudo random signals; means for generating an electromagnetic wave signal serving as a carrier; means for modulating the output of the electromagnetic wave generation means with the first pseudo random signal;
A means for inputting the output of the electromagnetic wave generating means modulated by the first pseudo-random signal generator to a transmitting antenna that radiates an electromagnetic wave toward the in-furnace deposits, and a carrier component of the reflected signal received by the receiving antenna Detecting and removing means, second multiplying means for multiplying the detected signal by the second pseudo-random signal, and first and second integrating means for integrating outputs of the first and second multiplying means, respectively. Integrating means, first
And a means for measuring the difference between the times when the outputs of the second integrating means each have an extreme value, and the deposition height of the in-furnace deposit is determined from the time difference. A height measuring device (claim 5).

The pseudo-random signal has a periodicity which repeats in a certain long period, but the signal is considered to be random within one period, and an M-sequence signal is typical. .

In the present means, the product of the first pseudo-random signal and the second pseudo-random signal having slightly different frequencies is used as the measurement signal wave, which is modulated by the carrier wave and transmitted from the antenna to be measured. The reflected electromagnetic wave is received by the antenna and detected to extract only the measurement signal wave component. The transmitting and receiving antennas may be integrated or separate.

Generally, the relationship between the distance L to the object to be measured, the velocity c of the electromagnetic wave, and the time difference t between the transmission timing and the reception timing of the measurement signal wave is represented by L = t / (2c). In the means, the first pseudo-random signal is used as a measurement signal wave, and the waveform before the transmission and the waveform after the reception of the second pseudo-random signal have the same pattern as that of the first pseudo-random signal, and the second pseudo-random signal has a slightly different frequency. Since it is modulated (multiplied) by a random signal, the frequency of the first pseudo random signal is f, the difference between the frequencies of the first pseudo random signal and the second pseudo random signal is Δf, and the measured signal wave before transmission is Is modulated with a second pseudo-random signal and the received measurement signal wave is modulated with a second pseudo-random signal, the time difference between the extreme values of the respective integrated values is t ′, and L =
t ′ · Δf / (2f · c), which increases the resolution of the measurement distance when using a measuring instrument with the same measurement time resolution,
The measurement accuracy can be improved.

Further, in this means, since the pseudo random signal is used as the measurement signal waveform, the influence of noise or the like can be reduced.

A sixth means for solving the above-mentioned problems is as follows.
In the fifth means, when there are a plurality of extreme values of the output of the second integrating means, only those having a predetermined level or more among the extreme values are extracted, and the longest time delay among them is extracted. The present invention is characterized in that the extreme value that gives is used for calculating the deposition height (claim 6).

The seventh means for solving the above-mentioned problems is as follows.
In the fifth means, when there are a plurality of extreme values of the output of the second integrating means, only those having a predetermined level or more among the extreme values are extracted, and the shortest time delay among them is extracted. Is adopted for calculating the deposition height (claim 7).

An eighth means for solving the above-mentioned problems is as follows.
In the case of the fifth means, when there are a plurality of extreme values of the output of the second integrating means, only those having a predetermined level or more among the extreme values are extracted, and then the most signal level among them is extracted. The present invention is characterized in that a large extreme value is adopted for calculating the deposition height (claim 8).

The ninth means for solving the above-mentioned problems is as follows:
The fifth means is characterized in that it has means for calculating the deposition height for all extreme values of the output of the second integration means, and obtaining the frequency for each predetermined deposition height range. (Claim 9).

The sixth means to the ninth means can realize the first means to the fourth means, respectively.

A tenth means for solving the above-mentioned problems is an apparatus for measuring a deposition height of a deposit in a container, and means for repeatedly projecting an electromagnetic wave toward the deposit, and the deposit. Means for detecting electromagnetic waves reflected from the
Of the reflected signals obtained for one electromagnetic wave projection,
A means for extracting only those having a signal strength equal to or higher than a predetermined reference strength; a means for calculating the distance to the deposit from the time interval from the projection of electromagnetic waves to the detection for each of the extracted signals; A means for setting the longest distance among the calculated distances as a representative value for the projection of the electromagnetic wave, and means for calculating the distance to the deposit by averaging the representative values obtained repeatedly. The deposit height measuring device for deposits in a container according to the present invention (claim 10).

An eleventh means for solving the above-mentioned problems is an apparatus for measuring the deposition height of the deposit in the container, which means for repeatedly projecting an electromagnetic wave toward the deposit and the deposit. Means for detecting electromagnetic waves reflected from the
Of the detected electromagnetic waves, a means for extracting one having a signal intensity equal to or higher than a predetermined reference intensity, and the extracted electromagnetic wave, the distance from the time interval from the electromagnetic wave projection to the detection to the deposit Calculate and from the distance,
A means for measuring the deposition height and the measured distance are divided into a plurality of regions in the height direction of the container that are divided in advance,
Means for counting the number of distance signals in each region,
At least one of the determination of the flow state of the raw material in the container, the determination of the scattering state of the raw material, and the reliability of the measurement of the layer height in the container from the frequency distribution of the measured distances in the plurality of boundaries in the height direction. An apparatus for measuring a deposition height of deposits in a container (claim 11), characterized in that the apparatus has means for performing.

The tenth means and the eleventh means can implement the first means and the fourth means, respectively.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of an example in which the present invention is used for measuring the height of a raw material layer in a gasification melting furnace. In FIG. 1, 1 indicates a gasification melting furnace,
2 is an input hole for waste as a raw material, 3 is a tuyere for blowing hot air in the lower part of the furnace, 4 is in the lower part of the furnace, there is little movement, and the density of the fixed bed is high, and 5 is above the fixed bed A fluidized bed which exists and flows at a relatively high density, and 6 represents a scattered bed which exists at a low density in the furnace. 7 is generation of microwave,
An electromagnetic wave transmission / reception device for detection, 8 is a microwave antenna for transmitting microwaves into the furnace and detecting reflected signals, and 9 is a signal processing device.

In the gasification and melting furnace 1, waste materials as raw materials, coke as auxiliary materials, etc. are continuously charged through the waste material input holes 2 and hot air is blown from the tuyere 3 at the bottom of the furnace to burn the raw materials. , Melt. The burning raw material forms a fixed bed (furnace core) 4 mainly composed of carbon, and the hot air that passes through the fixed bed and rises burns and melts the raw material (waste) above the fixed bed, and the molten raw material Is dropped in the gap of the furnace core and is discharged outside the furnace as slag from the slag hole at the bottom of the furnace.

A microwave signal is generated by an electromagnetic wave transmitting / receiving device 7 installed on the upper part of the furnace, and a microwave antenna 8
(Here, two microwave horn antennas for transmission and reception are installed side by side in the center of the upper part of the furnace.) A microwave signal is sent toward the inside of the furnace, and the object (waste) inside the furnace Receives the reflected signal from. The received signal is input to the electromagnetic wave transmission / reception device 7, and a detection signal having a time delay corresponding to the distance to the object is generated and output by signal processing.

The detection signal is input to the signal processing device 9.
The signal processing device 9 calculates and outputs the bed height in the furnace. Since the actual raw material in the furnace has a fluidized bed and a scattered bed, the reflected signal is not a single pulse but a superposition of a plurality of pulses. Furthermore, the types and composition of raw materials (waste) actually input vary from general municipal waste to industrial waste, and even if the operating conditions such as air flow and raw material supply are constant, The state of flow and the state of dispersion of the are constantly changing and are not constant.

In the signal processing device 9, a measurement value representative of a detection signal obtained by transmitting and receiving microwaves is obtained by signal processing, and further, averaging processing etc. is performed on the measurement value of the detection signal obtained repeatedly, and the inner layer height of the furnace is increased. Output as measured value.

FIG. 2 shows an example of an algorithm for obtaining the representative value of the detection signal in this embodiment. In the present embodiment, the detection signal is input to the signal processing device 9, converted into digital data, and processed as a digital data string.

In the signal processing device 9, first, all of the plurality of pulse signals in the detection signal are detected. Here, regarding a certain point, the point where the data within a certain range before and after on the time axis is smaller than that point is discriminated as a pulse. However, the waveform is differentiated, and the pulse of the waveform (maximum from the 0 point of the differential waveform It is also possible to identify points).

Next, it is determined that the peak value of the determined pulse signal is larger than a predetermined reference value. this is,
This is performed in order to suppress the influence of noise components included in the detection signal. Next, of the pulse signals that have been discriminated as pulses and have a value equal to or greater than a certain standard, the one with the longest distance is discriminated and used as the representative value of the detection signal.

Similarly, among the pulse signals which are discriminated as a pulse in the detection signal and have a value equal to or greater than a certain reference, the one having the largest pulse value is set as the representative value, and the closest one is set as the representative value. This can be selected by the signal processing device.

Here, all pulse waveforms included in the detection signal input to the signal processing device are discriminated, but the distance (or distance range) to the object to be measured is known in advance, or the physical distance is physical. If the measurement distance range is limited due to restrictions (such as when there is no object at a distance farther than the bottom of the furnace), process only the pulse waveform that exists in that distance range and reduce the load on the signal processing device. It is also possible to reduce.

Although the method of processing digital data by software by the signal processing device has been described here, similar processing can be realized by hardware and applied.

FIG. 3 shows a configuration example of the distance measuring device (electromagnetic wave propagation time measuring device) used in the present embodiment.
10 and 11 are pseudo random signal generators, 12 is a carrier signal generator, 13, 14, 15, 16 and 17 are frequency mixers, 18 and 19 are signal amplifiers, 20 and 21 are signal distributors, 22, 23 and 24. Is a low pass filter, 25, 26
Is a squarer, 27 is an adder, and 28 is a signal processing device.

In this example, the pseudo random signal generator 10,
An M-sequence signal generator constituted by a shift register having a feedback loop is used as 11, and a binary M-sequence signal having a code length 127 and frequencies 1525.000 MHz and 1525.005 MHz is generated. The output of the pseudo random signal generator 10 is the output of the carrier signal generator 12, and the frequency is 18 GH.
It is input to the frequency mixer 13 together with the z mm-wave signal, and the carrier signal is two-phase modulated by the pseudo random signal.

The carrier signal modulated by the pseudo-random signal is output to the outside through the signal amplifier 18 and supplied to the antenna through the coaxial cable. The reflected signal radiated from the transmitting antenna and received by the reflected wave receiving antenna at the object is input to the range finder, amplified by the signal amplifier 19, and then input to the frequency mixer 14.

In the frequency mixer 14, the input received signal and the output of the second pseudo random signal generator 11 are multiplied, and the output of the frequency mixer 14 is divided into two equal parts by the signal distributor 20. , 16 are input. The signal from the carrier signal generator is input to the signal distributor 21, two signals having different signal phases of 90 ° are output, and input to the frequency mixers 15 and 16 to detect the carrier component of the received signal. The outputs of the frequency mixers 15 and 16 are input to the low pass filters 22 and 23 and the frequency band is limited. The outputs of the low-pass filters 22 and 23 are squared by the squarers 25 and 26 and then added by the adder 27, and the result of carrying out carrier wave detection and correlation processing of the pseudo-random signal on the received signal is output as a detection signal. .

The outputs of the first and second pseudo random signals are directly input to the frequency mixer 17 and multiplied, and then the frequency band is limited by the low-pass filter 24, and output as a time reference signal having no time delay due to propagation. The reflection signal from the object is detected as a pulse waveform in the detection signal, and the distance to the object can be calculated by measuring the delay with respect to the time reference signal. Further, when there are reflection signals from a plurality of objects with different distances, a waveform in which a plurality of pulse waveforms with different positions on the time axis are superimposed is obtained.

In the measuring device of this embodiment, as shown in FIG.
As shown in, when electromagnetic waves (microwaves) are projected from above the furnace body while the object in the furnace is flowing and scattering, multiple reflection signals from multiple flowing and scattering targets are obtained. To be In the figure, the reflected signal is expressed as a signal in which a plurality of pulse signals are superimposed. The intensity of the reflected signal is flowing,
It varies depending on the shape, size, and density of scattered objects.

At this time, of the reflection signals obtained, the reflection signal farthest from the antenna passes through a plurality of targets in the furnace which flow and scatter, and is fixed below the flow and scatter layer. It is considered to be a reflection signal from a flow or scattered matter existing at a position close to the bed or the fixed bed.

Therefore, as described above, among the reflection signals obtained for one projection of the electromagnetic wave, the reflection signal having the signal intensity equal to or higher than the predetermined reference intensity and having the longest distance is discriminated. However, the distance value obtained by calculating the distance and using it as a representative value for the projection of the electromagnetic wave and averaging the representative values obtained repeatedly can be considered as the level of the fixed layer existing below the flow and scattering layers. .

Further, when only the flow and scattering layers mainly exist in the furnace, the reflection signal with the longest distance is considered to correspond to the reflection signal from the bottom of the furnace. It becomes impossible to detect the change of the bed height.
In this case, a reflection signal having a signal intensity equal to or higher than a predetermined reference intensity among the reflection signals obtained for one projection of electromagnetic waves and having the largest signal intensity is discriminated, and the distance is determined. By calculating and using the representative value for the projection of the electromagnetic wave and averaging the repeatedly obtained representative values, it is possible to obtain the level of a layer having a relatively large shape and a high density in the flowing and scattering layers. .

In the operation and control of the furnace body, flow,
When the upper limit value of the scattering layer is required, the reflection signal having a signal intensity equal to or higher than a predetermined reference intensity among the reflection signals obtained for one electromagnetic wave projection and having the shortest distance. It is possible to obtain the upper limit value of the flow and scattering layers by discriminating the signal, discriminating the reflected signal, calculating the distance, setting the representative value for the projection of the electromagnetic wave, and averaging the representative values obtained repeatedly.

When the flow and scattering state in the furnace is strong and the density of scattered materials in the furnace is high, the electromagnetic waves propagating in the furnace are reflected and scattered, and are sequentially attenuated. Therefore, as shown in FIG. In some cases, the reflection signal from the lower part of the furnace may not be obtained even though the reflection signal from the scattered material in the upper part of the furnace is obtained. Even in such a case, if the reflected signal is obtained, it is possible to perform the above-mentioned processing to calculate and output the level value, but it is not reliable as a measured value. Although it is not possible to judge the reliability of the measured value only by the output measured value, for a plurality of reflected signals obtained for the projection of the electromagnetic wave, it exists in a plurality of regions in the height direction of the furnace divided in advance, And counting the number of reflection signals having a signal intensity equal to or higher than a predetermined reference intensity, from the number of reflection signals in each region, the flow state of the raw material in the furnace, the determination of the scattering state in the furnace and the furnace It is possible to judge the reliability of the height measurement. For example, regarding the two regions of the upper and lower parts of the furnace body, the number of reflected signals existing in each region is counted, and when the number of reflected signals of the upper part is larger than the number of reflected signals of the lower part, scattering in the furnace It can be judged that the condition is severe. Also, in that case, since the reflection and scattering of electromagnetic waves in the upper part of the furnace increase, it is possible that the electromagnetic waves are attenuated in the lower part of the furnace and the reflected signal from the target object in the lower part of the furnace cannot be detected. It is also possible to determine that the reliability of the has deteriorated.

Hereinafter, in the distance measuring device shown in FIG.
The principle by which the distance to the measuring object can be accurately measured will be described.
The output m1 (t) of the pseudo random signal generator 10 is the mm-wave signal S of the frequency of 18 GHz which is the output of the carrier signal generator 12.
(t) = A ・ sin (ωt) is input to the frequency mixer 13,
The carrier signal S (t) is two-phase modulated by the pseudo-random signal m1 (t) and the transmission signal is Tx (t) = s (t) ・ m1 (t) = A ・ sin (ωt) ・ m1 (t). Become.

The transmission signal modulated by the pseudo random signal is output to the outside through the signal amplifier 18 and supplied to the horn antenna through the coaxial cable. The signal radiated from the transmitting horn antenna and reflected by the object is received by the reflected wave receiving horn antenna. The received reflected signal Rx (t) = A · sin (ωt + ωΔt) · m1 (t + Δt) is input to the distance measuring device, amplified by the signal amplifier 19, and then input to the frequency mixer 14 ( Δt is the delay time from transmission to reception).

The received signal input by the frequency mixer 14
Rx (t) and the output m2 (t) of the second pseudo random signal generator 31
And Rxm (t) = A ・ sin (ωt + ωΔt) ・ m1 (t +
Δt) · m2 (t) is obtained. The output of the frequency mixer 14 is divided into two equal parts by the signal distributor 20, and the frequency mixer 15,
16 is input. The signal s (t) from the carrier signal generator is input to the signal distributor 21 and the signal phase differs by 90 °.
Two signals, sin (ωt) and cos (ωt), are output and input to the frequency mixers 15 and 16 to detect the carrier component of the received signal.

That is, the output of the frequency mixer 15 is Si (t) = Rxm (t) · sin (ωt) = A · sin (ωt + ωΔt) · m1 (t + Δt) · m2 (t) · sin ( ωt) = A · m1 (t + Δt) · m2 (t) (cos (ωΔt) -cos (2ωt + ωΔt)) / 2. Here, since the high frequency component cos (2ωt) having a high frequency with respect to the carrier wave can be ignored, the output of the mixer 15 is Si (t) = A · m1 (t + Δt) · m2 (t) · cos (ωΔt) Similarly, the output of the mixer 16 is Sr (t) = A · m1 (t + Δt) · m2 (t) · sin (ωΔt) / 2.

Each signal is band-limited by the low-pass filters 22 and 23. This is equivalent to the integration process, and the output passed through each low-pass filter is Si '(t) = A.Φ (t) .cos ( ωΔt) / 2 Sr '(t) = A ・ Φ (t) ・ sin (ωΔt) / 2

[0057]

[Equation 1]

It becomes Here, T is the period of the pseudo random signal. Since the frequencies of m1 (t) and m2 (t) are slightly different, the phase between m1 (t) and m2 (t) will gradually shift over time, so Φ (t) will change over time. The result is the same as the result of the cross-correlation that has changed recently.

These two outputs Si '(t) and Sr' (t) are squared by the squarers 25 and 26, respectively, and added by the adder 27. Therefore, the output of the adder 27 is A2.Φ (t) 2/4. That is, the output of the adder 27 is the received signal m1 (t + Δ
t) and the output signal m2 (t) of the oscillator 21 are squared.

On the other hand, the outputs of the first and second pseudo random signal generators 10 and 11, m1 (t) and m2 (t), are directly input to the frequency mixer 17 and, after being multiplied, by the low pass filter 24 in the frequency band. It is output as a time reference signal that is limited and has no time delay due to propagation. That is, the output of the low pass filter 24 becomes the correlation between the signals m1 (t) and m2 (t).

Comparing the output of the low-pass filter 25, which is the reference signal, with the output of the adder 27, which is the detection signal,
The latter m1 signal has a delay of Δt. Based on the above-mentioned principle, if the frequency of m1 is F and the frequency of m2 is F + ΔF, the low-pass filter 25 is caused by the delay of Δt.
And the difference in the time when the peak appears in the output of the adder 27 is F /
Expanded to ΔF. In the present embodiment, F = 152
Since it is 5.000 MHz and ΔF = 1525.005 MHz, the time difference is expanded by about 305,000 times, and it is possible to accurately measure a change in a short distance.

The detection signal and the time reference signal are the signal processing device 2
8 is input. The signal processing device 28 measures the time lag of the detection signal with respect to the time reference signal and its change, and calculates and displays the distance from the antenna to the object from the propagation speed of the mm wave (almost the speed of light in air).

[0063]

As described above, according to the present invention,
It is possible to provide a method and an apparatus capable of accurately measuring the deposition height of deposits in a container even when an object flows or scatters.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of an example in which the present invention is used for measuring a layer height of a raw material in a gasification melting furnace.

FIG. 2 is a diagram showing an example of an algorithm for obtaining a representative value of a detection signal in the present embodiment.

FIG. 3 is a diagram showing one configuration example of a distance measuring device (electromagnetic wave propagation time measuring device) used in the present embodiment.

FIG. 4 is a diagram showing an example of a plurality of reflection signals obtained from a plurality of targets in a state where an object in a furnace is flowing and scattering.

FIG. 5 is a diagram showing an example of a reflection signal obtained when the flow and scattering conditions in the furnace are severe and the density of scattered materials in the furnace is high.

[Explanation of symbols]

1 ... Gasification and melting furnace, 2 ... Waste input hole, 3 ... Tuyere, 4 ...
Fixed layer, 5 ... Fluidized bed, 6 ... Scattered layer, 7 ... Electromagnetic wave transmitting / receiving device, 8 ... Microwave antenna, 9 ... Signal processing device, 1
0, 11 ... Pseudo random signal generator, 12 ... Carrier signal generator, 13, 14, 15, 16, 17 ... Frequency mixer, 18, 19 ... Signal amplifier, 20, 21 ... Signal distributor, 22, 23, 24 ... Low-pass filter, 25,26
... Squarer, 27 ... Adder, 28 ... Signal processing device

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G01S 13/10 G01F 23/28 DF term (reference) 2F014 AA05 AC06 FC01 3K062 AA16 AB03 AC01 BA02 CA05 CB03 4K046 HA11 LA03 4K056 AA19 BA01 BB01 CA20 FA11 FA17 5J070 AB01 AC03 AD01 AE20 AH02 AH14 AH19 AH33 AK22 AK26

Claims (11)

[Claims] 1. A method for measuring a deposition height of a deposit in a container, which comprises repeatedly projecting an electromagnetic wave from the top of the container, detecting a reflected signal from the deposit, and measuring the time from projection of the electromagnetic wave to detection. In the method of calculating the distance from the interval to the deposit and measuring the deposit height from the distance, the reflection signal obtained for one projection of the electromagnetic wave is equal to or greater than the predetermined reference intensity. Only those having signal strength are extracted, the distances are calculated based on the respective signals, and the longest distance among them is used as the representative value for the projection of the electromagnetic wave, and the representative values obtained repeatedly are averaged. A method for measuring the deposition height of a deposit in a container, characterized in that the distance to the deposit is calculated and the deposition height is measured from the distance. 2. A method for measuring a deposition height of a deposit in a container, which comprises repeatedly projecting an electromagnetic wave from the top of the container, detecting a reflected signal from the deposit, and measuring the time from projection of the electromagnetic wave to detection. In the method of calculating the distance from the interval to the deposit and measuring the deposit height from the distance, the reflection signal obtained for one projection of the electromagnetic wave is equal to or greater than the predetermined reference intensity. Only those having signal strength are extracted, the distances are calculated based on the respective signals, and the shortest distance among them is used as a representative value for the projection of the electromagnetic wave, and the representative values obtained repeatedly are averaged. A method for measuring the deposition height of a deposit in a container, characterized in that the distance to the deposit is calculated and the deposition height is measured from the distance. 3. A method for measuring the deposition height of a deposit in a container, which comprises repeatedly projecting an electromagnetic wave from the top of the container, detecting a reflected signal from the deposit, and measuring the time from projection of the electromagnetic wave to detection. In the method of calculating the distance from the interval to the deposit and measuring the deposit height from the distance, the reflection signal obtained for one projection of the electromagnetic wave is equal to or greater than the predetermined reference intensity. By discriminating a reflection signal having a signal strength and having the largest signal strength, calculating the distance based on the reflection signal as a representative value for projection of the electromagnetic wave, and averaging representative values obtained repeatedly. A method for measuring the height of a deposit in a container, which comprises calculating the distance to the deposit and measuring the height of the deposit from the distance. 4. A method for measuring the deposition height of a deposit in a container, which comprises repeatedly projecting an electromagnetic wave from the top of the container, detecting a reflected signal from the deposit, and measuring the time from projection of the electromagnetic wave to detection. In the method of calculating the distance from the interval to the deposit and measuring the deposition height from the distance, the height of the container divided in advance for a plurality of reflection signals obtained for the projection of electromagnetic waves from the top of the container. Counting the number of reflected signals that are reflected from within the plurality of regions in the depth direction and that have a signal intensity equal to or higher than a predetermined reference intensity,
From the number of reflection signals in each region, at least one of the process of determining the flow state of the raw material in the container, determining the scattering state of the raw material, and determining the reliability of the height measurement in the container Method for measuring height of sediment in container. 5. A first pseudo random signal generating means for generating a pseudo random signal, and a second pseudo random signal for generating a pseudo random signal having the same signal pattern as the first pseudo random signal but a slightly different frequency. Generating means,
First multiplication means for multiplying the first and second pseudo random signals; means for generating an electromagnetic wave signal serving as a carrier; means for modulating the output of the electromagnetic wave generation means with the first pseudo random signal; Means for inputting the output of the electromagnetic wave generation means modulated by the pseudo-random signal generator into a transmitting antenna that radiates electromagnetic waves toward the in-furnace deposits, and the carrier component of the reflected signal received by the receiving antenna is detected. Removing means, second multiplying means for multiplying the detected signal by the second pseudo-random signal, and first and second
The first and second integrating means for respectively integrating the outputs of the multiplying means and the means for measuring the difference between the times when the outputs of the first and second integrating means are extreme values are provided, and from the time difference,
A deposition height measuring device for deposits in a container, which is characterized in that a deposition height of deposits in a furnace is obtained. 6. The deposition height measuring apparatus for deposits in a container according to claim 5, wherein, when there are a plurality of extreme values of the output of the second integrating means, a predetermined level or more of the extreme values is provided. A deposit height measuring device for deposits in a container, wherein only the one of the above is extracted and the extreme value which gives the longest time delay among them is adopted for the calculation of the deposit height. 7. The deposition height measuring device for deposits in a container according to claim 5, wherein, when there are a plurality of extreme values of the output of the second integrating means, a predetermined level or more of the extreme values is provided. A deposit height measuring device for deposits in a container, which is characterized in that after extracting only the deposits, the extreme value giving the shortest time delay among them is adopted for calculating the deposit height. 8. The deposition height measuring device for deposits in a container according to claim 5, wherein, when there are a plurality of extreme values of the output of the second integrating means, a predetermined level or more of the extreme values is provided. A deposit height measuring device for deposits in a container, characterized in that, after extracting only the deposit, the extreme value with the highest signal level is adopted for calculating the deposit height. . 9. The deposition height measuring device for deposits in a container according to claim 5, wherein the deposition height is calculated for all extreme values of the output of the second integrating means, and the predetermined deposition is performed. A deposit height measuring device for deposits in a container, comprising means for determining a frequency for each height range. 10. An apparatus for measuring a deposition height of a deposit in a container, comprising: a unit for repeatedly projecting an electromagnetic wave toward the deposit; a unit for detecting an electromagnetic wave reflected from the deposit; 1 Means for extracting only the reflected signal obtained for a single projection of electromagnetic waves having a signal strength equal to or higher than a predetermined reference strength, and for each extracted signal, from projection of electromagnetic waves to detection Means for calculating the distance from the time interval to the deposit, means for making the longest distance of the calculated distances a representative value for the projection of the electromagnetic wave, and averaging the representative values repeatedly obtained And a means for calculating the distance to the deposit by means of the above. 11. An apparatus for measuring a deposition height of a deposit in a container, comprising means for repeatedly projecting an electromagnetic wave toward the deposit, means for detecting an electromagnetic wave reflected from the deposit, and detection. Means for extracting one having a signal strength equal to or higher than a predetermined reference strength among the generated electromagnetic waves,
For the extracted electromagnetic waves, the distance to the deposit is calculated from the time interval from the projection to the detection of the electromagnetic waves, the means for measuring the deposition height from the distance, and the measured distance is a container divided in advance. , A means for counting the number of distance signals in each area and a frequency distribution of the measured distances in the plurality of boundary areas in the height direction, and the flow state of the raw material in the container An apparatus for measuring a deposition height of deposits in a container, comprising: a means for performing at least one of determination of the above, determination of the scattering state of raw materials, and determination of the reliability of measurement of the layer height in the container.