JPS6117360Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a device for determining the state of wear and tear on the refractory lining in blast furnaces, converters, and other industrial furnaces. This invention relates to a device that can apply radio waves, automatically analyze the reflected waves, and visually display the state of wear and tear on the refractory lining in a furnace.

[Prior art and its problems] Conventionally, in order to determine the wear condition of the refractory lining inside a blast furnace, converter, etc., a line was buried in the refractory lining, and a staircase wave was connected to the buried line using a coaxial cable. , is applied via a voltage divider etc., the reflected wave from the buried line is taken out from the voltage divider, and from the waveform of the reflected wave, a waveform part corresponding to the starting end of the buried line and a waveform corresponding to the terminal end are obtained. By detecting the length of the buried line, the length of the buried line was calculated and the state of wear and tear of the refractory lining was determined. As a method of detecting the start and end ends of the buried line in the reflected waveform, it has been widely used to record the reflected waveform with a recording needle, or to display it on the screen of an oscilloscope and manually distinguish it. . However, this method not only requires a great deal of labor and time, but also has the disadvantage of causing measurement errors due to reading errors. In addition, in the method of simply determining the length of a line, when applying a step wave and determining the length of the line from the reflected waveform, there is a method of automatically detecting the end position of the line from the value of the first derivative of the reflected waveform. is already known. however,
Since it is necessary to detect the wear and tear of the refractory at various locations in the furnace, buried lines used to determine the state of wear and tear on the refractory are used with different lengths depending on the buried location. Furthermore, since coaxial cables of various lengths are installed at the same time to connect to buried lines, conventionally known methods cannot automatically calculate the lengths of these lines of various lengths. cannot be detected. Not only that, but the reflected waveform often contains a considerable amount of noise that is harmful or unnecessary when calculating the length of the buried line, and this can easily lead to errors in calculating the length of the buried line. There were flaws. Furthermore, in furnaces that operate continuously for long periods of time, such as blast furnaces, the accuracy of the equipment that detects the wear and tear of refractories must be maintained over a long period of time. The only way to manually inspect the accuracy of the device is to manually inspect the accuracy of the device, and it has been difficult to accurately and automatically detect the state of wear and tear on the refractory over a long period of time.

The purpose of the present invention is to solve all the problems of the conventional wear condition determination device for refractory linings as described above, and to provide a new device that accurately and automatically determines the wear condition of refractory linings over a long period of time. shall be.

[Means for solving the problem] A staircase wave is applied to the buried line in the refractory lining of a furnace such as a blast furnace via a coaxial cable, etc., and the reflected wave of the staircase wave is analyzed to determine the direction of the buried line. The main point of the means for determining the state of wear and tear of the refractory lining in the furnace by measuring the length is to extract a waveform portion of a predetermined width from the reflected wave of the step wave, including the waveform portion reflected from the buried line portion. An extraction and expansion circuit extracts and expands, and an expansion waveform signal output from the extraction and expansion circuit is input to detect the starting end waveform part of the buried line by a differential method, and a predetermined predetermined value in the expansion waveform signal is input. a both-ends detection circuit that limits a waveform portion of a predetermined width at a position and detects the terminal waveform portion of the buried line by high-order differentiation of the waveform of the limited portion over second order differentiation; and an output from the both-ends detection circuit. A time calculation circuit that inputs a signal and calculates the signal propagation time between both ends of the buried line, and a standard line of known length that inputs the propagation time signal output from the time calculation circuit and sets this propagation time separately in advance. and a line length calculation circuit that calculates the length of the buried line by comparing it with the standard propagation time obtained in the same manner.

[Operation] According to the above solution, the extraction and enlargement circuit extracts and enlarges the waveform portion of a predetermined width that includes the reflected portion necessary for calculating the length of the buried line, and the both end detection circuit extracts and enlarges the waveform portion of the enlarged waveform signal. In addition to differentially detecting the starting end waveform part, the ending waveform part is detected by performing higher-order differentiation on the limited waveform part that includes the ending waveform part.
To prevent confusion with unnecessary harmful noise that is inevitably included in a reflective part necessary for calculating the length of a buried line.

In addition, since the line length calculation circuit compares the propagation time signal between both ends of the buried line with the standard propagation time of a standard line of known length, which is prepared separately in advance, the measured value output of each circuit will change over time. Even if there is, there is no risk that the accuracy of calculating the length of the buried line will deteriorate.

[Examples] The present invention will be described below based on drawings showing examples thereof.

A device for determining the wear state of a refractory lining in a furnace according to the present invention (hereinafter referred to as the device) is a coaxial cable connected to a line 3 buried in a refractory lining 2 of a furnace 1 such as a blast furnace as shown in FIG. Applying a staircase wave through 4 mag.
This device determines the state of wear and tear on the refractory lining 2 by analyzing the reflected waves of the staircase waves and calculating the length of the buried line 3.

FIG. 2 is a block diagram of the proposed device. In the same figure, reference numeral 6 denotes a known voltage divider, which is connected to the staircase wave generator 5, as well as a line 7, a coaxial cable switch 8, a coaxial cable 4, and a connector 9.
It is connected to the buried line 3 via. The voltage divider 6 applies the staircase wave input from the staircase wave generator 5 to the buried line 3 and
The reflected wave is output in a superimposed manner with the staircase wave (this weight wave is referred to as a reflected wave in this specification).

Reference numeral 10 denotes an extraction/enlarging circuit which inputs reflected waves having a shape as shown in FIG. Then, the waveform portion of width A is extracted and enlarged as shown in FIG. In this case, the predetermined width A to be extracted and expanded by the extraction and expansion circuit 10 is determined as follows. In Figures 3 and 4, a indicates a waveform portion of the reflected wave reflected at the terminal end 31 of the buried line 3, and b indicates a waveform portion of the anti-elbow wave reflected at the start end 32 of the buried line 3. The interval T (time) from the waveform portion b is a value necessary for calculating the length of the buried line 3. By the way, the positions of the waveform parts a and b gradually change over many years due to line end wear of the buried line 3 and changes in equipment output over time, but the maximum value of the line end wear dimension of the buried line 3 can be estimated from the empirical value of the maximum amount of wear and tear on refractories, and the degree of change over time in the output of various equipment is also known empirically, so the reflected waveform parts a and b
The range in which the position of can change can be predicted. The predetermined width A is determined based on this prediction. That is, the predetermined width A is set in advance so that even if the position changes as described above, the range always includes the reflected waveform portions a and b, and the range is as narrow as possible, the range is We decided to extract and enlarge the waveform part within. Such an extraction enlargement circuit 10 includes, for example, a setting device 101 for setting the position and predetermined width A of a waveform portion to be extracted and the degree of enlargement thereof, a sweep circuit 102, and a sample hold circuit 103, which are connected as shown in the figure. It is possible to use known circuits.

Reference numeral 11 denotes a both-end detection circuit to which the enlarged waveform signal outputted from the extraction enlargement circuit 10 is input. The both ends detection circuit 11 is a circuit that analyzes the input expanded wave as shown in FIG. 4 and detects the end waveform part a and the start waveform part b in the following manner. That is, since the starting edge waveform portion b changes sharply, it can be detected by, for example, first-order differentiation of the enlarged waveform. On the other hand, since the degree of change of the terminal waveform part a is not as sharp as that of the waveform part b, it is desirable to detect it by higher-order differentiation such as second-order differentiation. In addition,
The enlarged waveform inevitably contains waveform parts such as reflected noise shown as e in FIG. Therefore, when detecting the terminal waveform part a by differentiation, there is a risk of confusion. Therefore, in the present invention, when detecting the waveform part a, a predetermined By detecting the terminal waveform part a from within the waveform part of width E, the above-mentioned confusion is prevented. As mentioned above, the position of the terminal waveform part a gradually changes due to line end wear of the buried line 3 and changes over time in the output of the equipment, but the range of change is the same as the range of change due to wear of the refractory 2 (Fig. 1). (see C and D), and the range of the degree of change over time in the output of the equipment, etc., and it will stay within a certain range based on experience. For example, in FIG. 4, the range from waveform portion c to waveform portion d is the range of change. Therefore, the differentiation start position and differentiation end position (i.e., the predetermined width E specified by both) of the waveform to be differentiated are determined so that a waveform portion that includes the change range and is as narrow as possible can be specified. That's what I do.
By doing this, the terminal waveform portion a can be detected without being disturbed by the noise as described above.

Reference numeral 15 denotes a time calculation circuit which inputs the both-end signals outputted from the both-end detection circuit 11 and calculates the signal propagation time T between both ends of the buried line 3. 16 is a line length calculation circuit which inputs the propagation time signal T outputted from the time calculation circuit 15 and calculates the propagation time T for a standard line 17 whose length is known in advance and which is provided separately outside the furnace. The length of the buried line 3 is calculated by comparing it with the propagation time previously determined and stored. The standard line 17 is made of the same material and has the same structure as the buried line 3, and is connected to the coaxial cable switch 8 via a coaxial cable 18 and a connector 13. Reference numeral 19 denotes a wear condition determination circuit which inputs the line length signal output from the line calculation circuit 16 and judges the wear condition of the lining refractory based on the buried line length. Reference numeral 20 denotes a display, which indicates the wear state of the furnace lining refractory based on the output signal from the wear state determination circuit 19. In FIG. 2, 3' and 3'' are buried lines of different lengths, which are connected to the coaxial cable switch 8.

Next, the functions of the present device will be explained.

First, the standard line 17 is connected to the line 7 by the coaxial cable switch 8, and a staircase wave is applied to the standard line 17. The reflected wave of the staircase wave is sent to the voltage divider 6.
, and is input to the extraction/enlargement circuit 10.
In the extraction/enlarging circuit 10, a waveform portion of a predetermined position and width A including the waveform portion reflected by the standard line 17 is extracted, enlarged, and output. The expanded waveform signal output from the extraction and expansion circuit 10 passes through the A/D converter 12 and is input to the both ends detection circuit 11, where the starting end of the standard line 17 is detected by the differential method. Further, the terminal end of the standard line 17 is detected from within the waveform of a predetermined width E at a predetermined position by the differential method. Incidentally, since the standard line 17 does not shorten over time, it goes without saying that the predetermined position and width A and the predetermined position and width E are set in consideration of this fact. The signal output from the both-end detection circuit 11 is input to the time calculation circuit 15, and based on the signal, the standard line 1
The standard propagation time of the step wave in 7 is calculated and output. The standard propagation time signal is input to the line length calculation circuit 18 and stored.

Next, the buried line 3 to be measured is switched and connected to the line 7. Applying a stepped wave to the buried line 3,
The reflected wave is subjected to various processing as described above, and the propagation time T of the buried line 3 is outputted from the time calculation circuit 15. The line length calculation circuit 16 inputting the propagation time signal T compares the propagation time T with the standard time of the standard line 17 stored in advance as described above, and calculates the length of the buried line 3. do. By doing so, even if the measured value output of a circuit such as the time calculation circuit 15 changes over time, the length of the buried line 3 can be calculated accurately. The length signal of the buried line 3 is input to a wear state determination circuit 19.

Similarly, the length signals of the other buried lines 3', 3'', ... are input one after another to the wear condition determination circuit 19.
The wear condition of the lining refractory 2 is determined based on the lengths such as 3', 3'', etc., and a judgment signal is output to the display 20.The display indicates the wear condition of the furnace lining refractory 2. Display graphically.

In addition, the switching of each buried line 3, 3', 3''... and standard line 17, and the extraction expansion circuit 10 associated with the switching
For example, the timing control circuit 2 can change the setting of the predetermined width of the
It is desirable that the switching and settings be changed automatically by 1.

Also, an averaging circuit may be interposed between the A/D converter 12 and the both-end detection circuit 11 (not shown). In that case, a plurality of staircase waves are applied to the buried line 3 by the staircase generating circuit 5, and the average of the data values of the corresponding waveform portions of the plurality of digitized waveform signals output from the A/D converter 12 is calculated by the averaging circuit, thereby obtaining an averaged expanded waveform signal. In this way, it is possible to cut out noise that occurs temporarily.

[Effects of the invention] As is clear from the above, the device of the present invention magnifies the waveform when analyzing reflected waves, so it is possible to calculate the length of the buried line with high accuracy, and also to calculate the length of the buried line. In calculating,
Since unnecessary waveforms and noise are cut out, the length of the buried line can be calculated accurately. Furthermore, even if the output of the equipment changes over many years, the length of the buried line is calculated using the standard line, so there is no concern that the accuracy of length calculation will deteriorate.

[Brief explanation of the drawing]

The drawings are all for explaining an embodiment of the proposed device, and FIG. 1 is a sectional view of the bottom of the blast furnace, FIG. 2 is a block diagram of the proposed device, and FIG.
The figure is a waveform diagram of the reflected wave, and FIG. 4 is a partially enlarged waveform diagram of the reflected wave. DESCRIPTION OF SYMBOLS 1... Furnace, 2... Lining refractory, 3... Buried line, 5... Staircase wave generator, 10... Extraction expansion circuit, 11... Both ends detection circuit, 15... Time calculation circuit, 16... ... Line length calculation circuit, 17 ... Standard line, 19 ... Wear state judgment circuit, 20 ... Display device.

Claims (1)

[Scope of utility model registration request] A staircase wave is applied to a buried line in the refractory lining of a furnace such as a blast furnace via a coaxial cable, and the reflected wave of the staircase wave is analyzed to measure the length of the buried line. In a device for determining the state of wear of a refractory lining, an extraction and expansion circuit extracts and expands a waveform portion of a predetermined width including a waveform portion reflected by a buried line portion from the reflected wave of the step wave, and from the extraction and expansion circuit. The starting end waveform part of the buried line into which the output enlarged waveform signal is input is detected by differential method, and a waveform part of a predetermined width at a predetermined position in the enlarged waveform signal is limited and the limited part is A both-end detection circuit detects the end waveform portion of the buried line by high-order differentiation over the second-order differential or higher of the waveform, and a signal output from the both-end detection circuit is input to calculate the signal propagation time between both ends of the buried line. The length of the buried line is calculated by inputting the propagation time signal outputted from the time calculation circuit and the propagation time signal outputted from the time calculation circuit and comparing this propagation time with a standard propagation time of which length is previously set. What is claimed is: 1. A wear state determination device for a furnace lining refractory, comprising: a line length calculation circuit, and determining a wear state of the furnace lining refractory based on the calculated length of the buried line.