JPH0226071Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention measures the level of the surface to be measured by stopping a mobile container such as a torpedo car or ladle when the surface to be measured comes directly under the level measuring device. Microwave distance used to stop the level measuring device and measure the level of the surface to be measured when the mobile level measuring device reaches the surface to be measured of the object to be measured or a stationary container, such as a ladle. This relates to a measuring device.

[Prior art and its problems]

To tap the blast furnace, as shown in Figures 1 and 2, the torpedo car 2 is set up so that the taphole 2a is directly below the pouring runner 1, and the microwave is placed above the taphole 2a. The distance measuring device 3 is arranged to measure the level of the injected hot metal 4, and when a certain level is reached, the tapping is stopped, and then the torpedo car 2 is replaced by the following one, which is carried out by visual monitoring and manual control. It is being carried out.

However, due to poor visibility conditions, the stopping position of the torpedo car 2 may shift, and in that case, since the pigtail hole 2a is narrow, the container around the pigtail hole is measured as the level, and the full signal is emitted. may be sent out and the vehicle may be moved empty.
This has been a hindrance to improving the reliability and operating rate of the equipment.

Such erroneous operation may also occur when slag adheres to the pigtail hole and the pigtail hole is deformed and reduced.

In FIG. 2, 5 is an antenna, 6 is a microwave circuit, and 7 is a signal processing device.

[Means for solving problems]

As a result of various studies, the inventors of the present invention have found that when the hot water surface is horizontal to the antenna 5, the obtained beat signal is large, but when it is on a slope, the signal is significantly attenuated due to a decrease in the reflected signal. Focusing on the large fluctuation in the envelope amplitude of the beat signal when the torpedo car enters the line, by detecting the fluctuation in the envelope amplitude of the beat signal, it is possible to determine whether the object to be measured is hot metal or not. By using the discrimination signal, it was possible to stop the torpedo car in a fixed position.

That is, the present invention is a device that measures the level of a surface to be measured by stopping a movable container when the surface to be measured comes directly under a level measuring device, or a device that measures the level of the surface to be measured by stopping a movable container when the surface to be measured comes directly under the level measuring device, or This microwave distance measuring device is used to measure the level of a surface to be measured by stopping the level measuring device when the level measuring device reaches the target surface, and the microwave distance measuring device is a microwave distance measuring device that measures the level of a surface to be measured by stopping the level measuring device when the level measuring device reaches the target surface. The beat signal is input to a known microwave distance measuring device that calculates and derives a distance signal to the surface to be measured from the period of the beat signal of the signal transmitted to the surface and the signal reflected from the surface to be measured. First and second bandpass filters with different bands, that is, a first bandpass filter that passes only a low frequency reflected signal from the vicinity of the injection port of the container, and a high frequency reflected signal from the surface to be measured or the ground. a second band filter that passes the
first and second power detection circuits that detect the magnitudes of the output signals of the first and second bandpass filters, respectively, and is sent when the output of the first power detection circuit exceeds a set value. an inverted signal of the signal;
an AND circuit that performs a logical product with a signal sent when the output of the second power detection circuit exceeds a set value; and stopping the mobile container or the mobile level measuring device when the output of the AND circuit changes. The stop command generation circuit sends out a pulse signal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a block diagram of one embodiment of the present invention, in which a microwave circuit 6 receives a modulation signal from a modulation signal generation circuit 8, radiates frequency-modulated microwaves from an antenna 5 to an object to be measured, and The reflected signal is received via the antenna 5, and a beat signal having a frequency _b ( _b = A.2R/C, A: constant, R: measurement distance, C: speed of light) is sent to the amplification circuit 9 in the signal processing board.

One of the signals amplified in this amplification circuit 9 is sent to the power detection circuit 11 through the first band filter 10, and the other signal is sent to the power detection circuit 13 and the distance calculation circuit 14 through the second band filter 12. It will be done.

The first band filter 10 passes only the reflected signal from the vicinity of the injection port of the torpedo car (lower frequency than the signal from the hot metal), and the second band filter 1
2 is a filter that passes reflected signals from the hot metal or the ground (if there is no torpedo car).

Further, the power detection circuits 11 and 13 detect the magnitude of the output signal, that is, the envelope amplitude after full-wave rectification.

The output signals of the power detection circuits 11 and 13 are converted into logic signals by comparators 15 and 16, respectively.

The signal passing through the comparator 15 is sent to the inverting circuit 1
After being inverted at step 7, the signal that has passed through the AND circuit 18 and the comparator 16 is directly sent to the AND circuit 18.
The AND signal is input to the stop command generation circuit 19.

This stop command generating circuit 19 uses, for example, a mono multivibrator, and generates a pulse signal as a torpedo car stop signal when the output signal of the AND circuit 18 changes from "L" to "H". Note that 20 in FIG. 3 is an output circuit.

Next, the actual operation will be explained with reference to the time chart and state diagram shown in FIG.

Now, as shown in Figure 4 b-, when there is no torpedo car and the ground is the measurement target (section)
In this case, the output A _L of the comparator 15 becomes "L", and the output B _L of the comparator 16 becomes "H".

Next, when torpedo car 2 enters the line as shown in Figure 4b-, the reflected signal is not returned because the torpedo's outer shape is slanted, and comparator 1
The outputs A _L and B _L of 5 and 16 are often in the "L" state, and occasionally when the topedo or circuit device cover 2b passes directly under the antenna 5, the A _L signal becomes "L".
then changes from “H” to “L” (section) Then, when the injection port 2a of the torpedo car approaches just below the antenna 5, the reflecting surface becomes horizontal, so: A _L signal goes from “L” to “H” and then the centers align. The signal near the furnace mouth disappears and is replaced by a reflected signal from the bottom of the empty pot or from the remaining hot water.
A _L signal changes from “H” to “L” B _L signal changes from “L” to “H” (section) Torpedo car stop signals are A _L signal (inverted signal of A _L ) and B _L signal AND logic output is “L”
Detects and outputs the time when the signal changes from to "H" to stop the torpedo car.

This prevents misalignment between the antenna 5 and the injection port 2a, allows the torpedo car to be set in an optimal state, and eliminates the situation where the microwave level meter cannot measure.

The above description has been made regarding the application to the stopping device of a torpedo car, but the present invention can also be applied in the opposite case, for example, when moving the antenna over the injection port of a container such as a ladle. By detecting changes in the signal due to changes in the field of view of the antenna from the top surface to the internal measurement surface, and fixing the positional relationship of the antenna to the object to be measured, it is possible to avoid a situation in which measurement is not possible.

Note that in the above embodiment, when the power is turned on (the fourth
There is a possibility that the stop command signal F is sent out on the circuit at t=0 in the figure. In order to completely prevent this, as in the embodiment shown in FIG.
This can be prevented by providing the A/L converter 22 and the AND circuit 23.

That is, as can be seen from FIG. 6, even if the mono-multivibrator 19a sends out a pulse when the power is turned on, it does not become the output of the AND circuit 23.

[Effect of idea]

As described above, according to the present invention, it is possible to stop a container such as a torpedo car or a ladle at the correct position, or to stop a moving level measuring device on the surface to be measured of a stopped container. This can greatly contribute to improving operating rates.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a plan view showing the positional relationship between the torpedo car and the tilting gutter, Fig. 2 is a partially cutaway front view thereof, and Fig. 3 is a block diagram of the electric circuit. , FIG. 4 is an explanatory diagram of the operation, FIG. 5 is a block diagram of a different embodiment, and FIG. 6 is an explanatory diagram of the operation. 5...Antenna, 6...Microwave circuit, 7...
...Signal processing device, 8...Modulation signal generation circuit, 9...
...Amplification circuit, 10...First band filter, 11 and 13...Power detection circuit, 12...Second band filter, 14...Distance calculation circuit, 15 and 16...
... Comparator, 17 ... Inversion circuit, 18 ... AND circuit, 19 ... Stop command generation circuit, 20 ...
Output circuit.

Claims (1)

[Claims for Utility Model Registration] A device that measures the level of a surface to be measured by stopping a movable container when the surface to be measured comes directly under a level measuring device, or a device that measures the level of a surface to be measured by stopping a movable container when the surface to be measured comes directly under a level measuring device, or In a microwave distance measuring device used to measure the level of a surface to be measured by stopping the level measuring device when the mobile level measuring device reaches the target surface, the microwave distance measuring device is used to measure the level of a surface to be measured by frequency modulated microwaves. A microwave distance measuring device that calculates and derives a distance signal to the surface to be measured from a beat signal period of a signal transmitted to the surface and a signal reflected from the surface to be measured, and inputs the beat signal. 1st and 2nd with different passbands
a bandpass filter, that is, a first bandpass filter that passes only low-frequency reflected signals from the vicinity of the injection port of the container, and a second bandpass filter that passes high-frequency reflected signals from the surface to be measured or the ground. , first and second power detection circuits that detect the magnitude of the output signals of the first and second bandpass filters, respectively, and a signal that is sent out when the output of the first power detection circuit exceeds a set value. an AND circuit that takes an AND of an inverted signal of the signal output from the second power detection circuit and a signal sent out when the output of the second power detection circuit exceeds a set value; A microwave distance measuring device comprising: a stop command generation circuit that sends out a pulse signal to stop the level measuring device.