JPH0592246A - Device for detecting abnormality of spray nozzle for continuous casting equipment - Google Patents

Abstract

PURPOSE:To device an abnormality, such as clogging of a spray nozzle in high accuracy by making piezoelectric element output effective values and further obtaining the summation of each sampling value. CONSTITUTION:The piezoelectric elements 6-1 to 6-n are arranged on an injecting surface of spray water to a dummy bar or a measuring carriage, etc., passing through continuous casting equipment. In the abnormality detecting instrument for deciding the abnormality of the spray nozzle in the continuous casting equipment based on the output signals of these piezoelectric elements 6-1 to 6-n, amplifiers 7-1 to 7-n for amplifying the outputs of the piezoelectric elements 6-1 to 6-n, root mean square value making circuits 8-1 to 8-n for obtaining the root mean square value of the amplified outputs by these amplifiers 7-1 to 7-n and a microcomputer 11 for obtaining the summation of each samplings P1-Pn in the root mean square value outputs with these root mean square value making circuits 8-1 to 8-n are provided. Based on the summation value SIGMAP obtd. by this microcomputer 11, the clogging of the spray nozzle is decided by the microcomputer 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a continuous casting facility.
The present invention relates to an abnormality detection device for detecting an abnormality in a secondary cooling spray nozzle with high accuracy.

[0002]

2. Description of the Related Art The secondary cooling system in a continuous casting facility is 1
The line is composed of several hundred to several thousand spray nozzles to solidify and cool the slabs, but if there is a spray nozzle abnormality such as nozzle clogging or nozzle omission, uneven cooling is performed. Therefore, surface cracks and internal cracks of the slab occur, which adversely affects the quality.

Conventionally, the detection of these nozzle abnormalities has been performed by a method in which a worker enters into a narrow machine to inspect. Since such manual work is inefficient and in a bad environment, a method has been proposed which eliminates the work of humans. For example,
Technology by water pressure detection in units of spray zones as shown in Japanese Utility Model Publication No. 57-59236, or Kawatetsu Technical Report 1980 Vol. 12, No. As described on page 540 of No. 3, there is a technique of inserting a television camera between rolls in the machine.

However, in the technique of detecting the water pressure in each spray zone as described above, since the number of spray nozzles in one zone is large, it cannot be detected unless a large number of nozzles have an abnormality. There's a problem.
On the other hand, there is also a method of subdividing the zone to increase the detectability, but there is a problem that the number of sensors increases and the scale becomes large. In addition, when using a TV camera, it is necessary to insert a dedicated inspection cart and scan the camera in the width direction during observation, which causes problems in workability and relies on visual confirmation of the spray water injection state. Therefore, there is a problem in improving detection accuracy and achieving quantification.

As one of the technologies proposed to solve such a problem, there is Japanese Utility Model Publication No. 3-4425.

That is, as shown in FIG. 7, the dummy bar 1 constructed so that it can be inserted into the machine consisting of the roll 2 and the spray header 3 at the start of casting is generally made by connecting a plurality of chain-shaped steel blocks. A sensor base 5 is attached to the surface of the dummy bar 1 facing the spray nozzle 4 of the spray header 3 so as to be parallel to the roll 2. A plurality of strip-shaped or linear piezoelectric elements 6 are continuously mounted on the sensor base 5 via a vibration-proof material. The piezoelectric element 6 uses a piezoelectric polymer composite, and is, for example, a piezoelectric material obtained by dispersing piezoelectric ceramic fine particles having a particle size of about 1 to several microns in synthetic rubber and binding a polymer. A piezoelectric element using such a piezoelectric polymer composite has a large piezoelectric coefficient and is flexible, and since ceramics are bonded with a polymer, it has characteristics such as strong impact force. There is. The reason why the piezoelectric element is mounted via the anti-vibration material is that shock vibration due to contact with the slab drawing roll when passing through the machine and vibration due to rocking of the dummy bar etc. are transmitted to the detection unit. This is to prevent this.

In the above construction, the dummy bar 1 solidifies the tip of the slab at the start of casting and moves it in the continuous casting equipment to extract from the lower end, but the dummy bar 1 has a predetermined speed (for example, 2 m / m). A detection signal is continuously obtained from the piezoelectric element 6 in the process of moving in the minute), and an abnormality such as clogging of the spray nozzle can be determined from the analysis of this signal.

FIG. 8 is an output waveform diagram of the piezoelectric element 6 in the abnormality detecting device of FIG. Here, the case where the number of piezoelectric elements 6 is 6 is shown. The piezoelectric element 6 converts the amount of electricity (voltage) corresponding to the pressure energy of the jet water 4a jetted from the spray nozzle 4. Since the output voltage of the piezoelectric element 6 has a small level, it is amplified and signal-processed by an amplifying means (not shown), and then an abnormality determination process based on the signal level is performed. In FIG. 8, the original signal waveform is shown.

In the case of FIG. 8, a large detection voltage is obtained when the pressure of water sprayed from the spray nozzle 4 is large, and the detection voltage is 0 when the spray nozzle 4 is clogged. In the figure, the circled portion indicated by the alternate long and short dash line is the portion where the nozzle is clogged, and the detection voltage cannot be obtained. Also,
If a pulse-shaped signal that protrudes from the envelope of the detected waveform appears, it can be considered as an injection abnormality.

[0010]

However, in the general continuous casting machine, in the arrangement of the spray nozzles in the width direction of the dummy bar, as shown in FIG. 5, the spray ejection range from the nozzle overlaps the adjacent spray range. Are often arranged like this. The upper part of FIG. 6 shows a waveform corresponding to the signal obtained by performing the effective grounding process on the signal shown in FIG.
A shows the waveform when the nozzle is normal and there is no clogging,
Shows a waveform when the nozzle is completely clogged. As shown by the waveform of B in FIG. 6, in a general continuous casting machine,
Even if the nozzle to be measured is clogged, the output is measured due to the influence of the spray of the adjacent nozzle. See also FIG.
The lower diagram shows the values obtained by A / D conversion of the signals shown in the upper stage and sampling by the microcomputer. Further, in FIG. 9, in order to investigate the relationship between the clogging degree of the nozzle and the output,
The average value P _a of the output and the peak value of the output when the amount of water of the target nozzle is arbitrarily changed from 3 l / min (nozzle normal) to 0 l / min ((completely clogged state) every 1 l / min Fig. 10 shows the relationship with Pmax, where both P _a and P max greatly vary with respect to the nozzle water amount, and when the nozzle is normal (3 l / min) and when the nozzle is completely clogged ( The difference of 0 l / min) is small, and it is difficult to make an accurate determination.

Therefore, an object of the present invention is to provide a spray nozzle abnormality detecting device for a continuous casting facility, which is capable of highly accurately determining an abnormality such as clogging of a spray nozzle.

[0012]

In order to achieve the above object, the present invention provides a piezoelectric element on a spray water jetting surface of a dummy bar or a measuring trolley that passes through a continuous casting facility. In an abnormality detection device for determining an abnormality of a spray nozzle of a continuous casting facility based on an output signal, an amplification means for amplifying an output signal of the piezoelectric element, and an effective value conversion means for obtaining an effective value of the amplified output by the means,
An arithmetic means for obtaining the sum of each sampling value in the effective value output by the means and a determining means for determining the clogging of the spray nozzle based on the sum value by the means are provided.

[0013]

According to the above-mentioned means, the output of the piezoelectric element is amplified, the effective value is obtained by the effective value converting means, and the effective value is output to the microcomputer via the A / D converter. Sampling is performed, and the total sum of the sampling values is obtained, and the presence or absence of clogging of the spray nozzle is determined based on this result. Therefore, an abnormality such as clogging of the spray nozzle can be determined based on the degree of configuration.

[0014]

1 is a block diagram showing an apparatus for detecting an abnormality in a spray nozzle of a continuous casting facility according to the present invention.

[0015] Each of the piezoelectric elements 6 _-1 to 6 _-n are connected amplifier 7 _-1 to _7--n for amplifying the output signal, each output of the amplifier 7 _-1 to _7--n thereof Effective value conversion circuits 8 _-1 to 8 _-n for converting an output signal into an effective value are connected. Further, a multiplexer 9 for selectively outputting one of n outputs is connected to each output of the effective value converting circuits 8 _-1 to 8 _-n , and this multiplexer 9 has an A / D (analog / digital). ) An A / D converter 10 for converting into a signal is connected. Further, the A / D converter 10 is connected to a microcomputer 11 for performing a process of determining an abnormality of the spray nozzle.

As is well known, the microcomputer 11 is a ROM (read only memory) in which a program is stored, a RAM for temporarily storing data and the like.
(Random access memory), interface circuit for inputting / outputting with external device, etc. are provided.
Further, as an external device in the microcomputer 10,
An input device 12 such as a keyboard, a storage device 13 using a floppy disk device or a hard disk device for storing data, a printer 1 for outputting processing results
4 and contents input by the input device 12, input data,
A display device 15 for displaying processing data, execution results, etc. is connected.

In the above structure, the piezoelectric elements 6 _{-1 to} 6 _-n
In each of the above, each time the spray nozzle 4 passes below the spray nozzle 4, an output signal having a signal component in which the signal synchronized with the roll passing signal has positive and negative signal components as shown in FIG. This piezoelectric element 6 _-1 ~
The output signals of 6 _-n are amplified to a predetermined level by each of the amplifiers 7 _{-1 to} 7 _-n because of the small signal level, and further, by the effective value converting circuits 8 _-1 to 8 _-n . As shown in, the effective value is obtained and a smooth waveform of only the one-way component is generated.

The output waveforms of the effective value converting circuits 8 _-1 to 8 _-n are as shown in FIG. 3, in which a is a bias value peculiar to the circuit, and b is a signal below the bias a. It is a preset value P _BL that is preset so as not to exist. Then, P ₁ , P ₂ , P _3, ... In the waveform are sampling values for each cycle t. Further, a waveform portion having a width L that is equal to or larger than the set value P _BL indicates a portion where the spray water from the spray nozzle 4 is in contact. The set value P _BL is set by the microcomputer.

The effective value conversion circuit 8 _-1 thus obtained
The output signals of ~ 8- _n are sequentially selected by the multiplexer 9, and any one of the output signals is selected by the A / D converter 10.
Is output to. The analog signal output from the multiplexer 9 as shown in FIG. 3 is an analog signal and cannot be received by the microcomputer 11 in the subsequent stage, and thus is converted into a digital signal by the A / D converter 10.
The digital signal obtained by this conversion is the microcomputer 1
1 at a fixed time interval t.

The values fetched by the microcomputer are the sampling values P ₁ , P ₂ , P ₃ .multidot.
The total sum ΣP (total sum of data in the width L portion, hereinafter referred to as total measurement) is calculated.

ΣP = P ₁ + P ₂ + P ₃ + ... P _n (1) On the other hand, the relationship between the amount of water discharged from the spray nozzle 4 and the reference total ΣP _B, which was obtained by actually operating the continuous casting equipment in advance, The reference sum ΣP _B is compared with the measured sum ΣP.

FIG. 4 shows the relationship between ΣP _B obtained by the above method and the amount of nozzle water. As shown in FIG. 4, ΣP _B has a proportional relationship corresponding to the change in the nozzle water amount, and its variation range is very small. Therefore, by preliminarily storing this relationship in a ROM (not shown) in the microcomputer 11 as a table and applying the measured total sum ΣP calculated by the microcomputer 11 to the reference total sum ΣP _{B of the} table, the relationship shown in FIG. Based on this, the amount of water discharged from the nozzle can be uniquely known. The result of this determination is displayed on the display device 15 and is printed out on the printer 14 as necessary.

Since this total value changes depending on the speed of the sensor, it can be dealt with by making the speed constant or converting it into a value at a certain constant speed based on the actual sensor speed result. It is possible.

[0024]

Since the present invention is configured as described above, it has the following effects.

In the spray nozzle abnormality detecting device for continuous casting equipment according to claim 1, a piezoelectric element is arranged on a spray water jetting surface of a dummy bar or a measuring carriage passing through the continuous casting equipment, and an output signal of the piezoelectric element is provided. An abnormality detecting device for determining abnormality of a spray nozzle of a continuous casting facility based on an amplifying means for amplifying an output signal of the piezoelectric element, an effective value converting means for obtaining an effective value of an amplified output by the means, and the means Since the calculating means for obtaining the sum of each sampling in the effective value output and the judging means for judging the clogging of the spray nozzle based on the sum value by the means are provided, an abnormality such as clogging of the spray nozzle can be detected. It can be determined with high accuracy.

[Brief description of drawings]

FIG. 1 is a block diagram showing a spray nozzle abnormality detection device for continuous casting equipment according to the present invention.

FIG. 2 is an explanatory diagram showing a signal output timing of the effective value conversion circuit in FIG.

FIG. 3 is a waveform diagram showing details of an output waveform of an effective value conversion circuit.

FIG. 4 is an explanatory diagram showing the contents of a water amount calculation table according to the present invention.

FIG. 5 is a cross-sectional view of the nozzle in the width direction of the dummy bar and an explanatory view showing a spraying range of the spray.

FIG. 6 is an explanatory diagram showing a relationship of output waveforms according to presence / absence of nozzle clogging.

FIG. 7 is a perspective view showing a conventional continuous casting facility spray nozzle abnormality detection device and continuous casting facility.

8 is an output waveform diagram of a piezoelectric element in the above detection device of FIG.

FIG. 9 is an explanatory diagram showing the contents of a water amount calculation table obtained by a conventional method.

[Explanation of symbols]

1 Dummy Bar 2 Roll 3 Spray Header 4 Spray Nozzle 5 Sensor Stand 6 _{-1 to} 6 _-n Piezoelectric Element 7 _{-1 to} 7 _-n Amplifier 8 _-1 to 8 _-n Effective Value Circuit 9 Multiplexer 10 A / D Converter 11 Microcomputer 12 Input device 13 Storage device 14 Printer 15 Display device

Claims (1)

[Claims] 1. A piezoelectric element is arranged on a spray water jetting surface of a dummy bar or a measuring trolley passing through the continuous casting facility, and an abnormality of a spray nozzle of the continuous casting facility is judged based on an output signal of the piezoelectric element. In the abnormality detection device, amplification means for amplifying the output signal of the piezoelectric element, and effective value conversion means for obtaining an effective value of the amplified output by the means,
A spray for continuous casting equipment, comprising: an arithmetic means for obtaining the sum of sampling values in the effective value output by the means; and a determining means for determining clogging of the spray nozzle based on the sum value by the means. Nozzle abnormality detection device.