JP3538956B2 - Temperature measuring method and temperature measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature measuring method and a temperature measuring device for measuring, for example, the surface temperature of a metal plate, and more particularly to measuring the surface temperature of a steel plate which is water-cooled during transportation. The present invention relates to a temperature measuring method and a temperature measuring device.

[0002]

2. Description of the Related Art When cooling a steel sheet while controlling the temperature of the steel sheet in a water cooling line or the like for cooling the steel sheet being conveyed with water, the surface temperature of the conveyed steel sheet is sometimes measured using a radiation thermometer. When using a radiation thermometer to measure the surface temperature of a steel sheet being transported in such a water cooling line, the presence of water vapor or cooling water between the steel sheet and the radiation thermometer There is. If water vapor or cooling water exists between the steel plate and the radiation thermometer, radiation energy radiated from the steel plate is absorbed by the water vapor or cooling water, causing an error in temperature measurement, The meter may get wet and the temperature measurement may become unstable.

Therefore, as a technique for eliminating such temperature measurement errors and instability of temperature measurement, water is jetted from a nozzle to form a water column between a waterproof radiation thermometer and a steel plate.
There has been proposed a technique of measuring the surface temperature of a steel sheet using a radiation thermometer while correcting, based on the height of the water column, the amount of radiant energy absorbed by the water column out of the radiant energy radiated from the steel sheet. (See Japanese Patent Publication No. 3-69974). According to this technique, since a water column is formed between the radiation thermometer and the steel plate, there is no water vapor or scattered water, and stable and accurate temperature measurement can be performed.

[0004]

However, in the above-mentioned conventional temperature measuring method, water is spouted from a nozzle with a considerable force in order to prevent the presence of water vapor or scattered water between the radiation thermometer and the steel plate. . Therefore, the steel sheet is cooled by the water, and the surface temperature of the cooled portion is measured. When measuring the surface temperature of a steel sheet being conveyed in a water cooling line or the like, originally, the surface temperature of the steel sheet cooled on the upstream side in the conveyance direction from the temperature measurement position is measured. In the measurement method, as described above, the steel sheet is cooled during the temperature measurement, and the surface temperature of the cooled portion is measured. For this reason, there is a problem that the surface temperature of the steel sheet itself cooled on the upstream side in the transport direction from the temperature measurement position cannot be measured. Further, since the steel plate is partially cooled by the water column formed at the time of temperature measurement, there is also a problem that the cooling unevenness occurs in the steel plate and the material of the steel plate becomes uneven.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a temperature measuring method and a temperature measuring method capable of measuring the surface temperature while suppressing a decrease in the surface temperature of the object when measuring the temperature, and reducing the uneven cooling of the object to be measured. It is intended to provide a device.

[0006]

According to the present invention, there is provided a temperature measuring method for measuring the surface temperature of an object based on radiant energy radiated from the object. A water column is formed between the device and the device under test, and the device under test is measured using the radiation thermometer while correcting the amount of radiant energy absorbed by the water column out of the radiant energy radiated from the device under test. In the temperature measuring method for measuring the surface temperature, the temperature of the water column is set to 60 ° C. or more when forming the water column.

According to another aspect of the present invention, there is provided a temperature measuring apparatus for measuring a surface temperature of an object to be measured based on radiant energy radiated from the object; Forming a water column between the gauge and the object to be measured, a nozzle header in which the radiation thermometer is disposed, and a measuring device for measuring the height of the water column, using the nozzle header Forming a water column between the radiation thermometer and the object to be measured, while correcting the amount of radiant energy absorbed by the water column among the radiant energy radiated from the object to be measured based on the height of the water column A temperature measuring device for measuring the surface temperature of the object to be measured using the radiation thermometer, a water supply means for storing water and supplying the water to the nozzle header, and a water supply means for storing the water in the water supply means. Heating hands When, it is characterized in that the water which is stored in the water supply means and a control means for controlling the heating means so that the temperature within a predetermined range.

[0008]

According to the temperature measuring method of the present invention, since a water column is formed between the object to be measured and the radiation thermometer, there is no water vapor or scattered water in the portion where the water column is formed. And temperature measurement errors caused by scattered water can be eliminated. Further, since the temperature of the water column is 60 ° C. or higher, a boiling film is easily formed on the surface of the object to be measured in contact with the water column, and the surface temperature of the object can be measured by suppressing the decrease in the surface temperature of the object. In addition, the cooling unevenness of the measured object is reduced.

Further, according to the temperature measuring apparatus of the present invention, the water stored in the water supply means is heated by the heating means and the control means.
It is heated to a temperature within a predetermined range. As the temperature within the predetermined range, by selecting a temperature at which a boiling film is formed on the surface of the object to be measured, which is in contact with the column of water formed using the nozzle header, the surface temperature of the object to be measured is suppressed from lowering. Not only can the surface temperature be measured, but also the cooling unevenness of the object to be measured can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the temperature measuring method and the temperature measuring apparatus according to the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a schematic diagram showing a state in which the temperature of a roll is measured using one embodiment of the temperature measuring device of the present invention.

Here, the surface of the roll 12 is measured by using a temperature measuring device 10 based on radiant energy radiated from a roll (an example of an object to be measured) 12 rotating in a direction indicated by an arrow 12a. An example of measuring temperature will be described. The temperature measuring device 10 includes a radiation thermometer 14 that measures a surface temperature of the roll 12 based on radiant energy radiated from the roll 12, and a nozzle header 18 that forms a water column 16 between the radiation thermometer 14 and the roll 12. And the nozzle header 18
And a water supply device 20 for supplying water to the water supply device. Water supply 2
At 0, water 20a supplied from a supply port (not shown) is stored, and the stored water 20a is heated using a heater (an example of a heating unit according to the present invention) 22. The heated water is supplied to the nozzle header 18 using a pump (not shown).
Supplied to The temperature of the water 20a stored in the water supplier 20 is measured by a thermometer 24, and the heater 22 is controlled by the controller 26 so that the temperature of the water 20a falls within a predetermined range. The radiation thermometer 14 is housed in a waterproof container 28 arranged in the nozzle header 18 so that temperature measurement does not become unstable. A glass window 28a is provided on a portion of the container 28 facing the observation surface 14a of the radiation thermometer 14. Radiation energy radiated from the roll 12 is observed by the radiation thermometer 14 through the water column 16 and the glass window 28a. In the radiation thermometer 14, the measured radiation energy is converted into a temperature by a known method.
In this conversion, of the radiant energy radiated from the roll 12, the amount of the radiant energy absorbed by the glass window 28a is corrected.

The correction of the radiation energy absorbed by the water column 16 among the radiation energy radiated from the roll 12 is as follows.
The measurement is performed using an ultrasonic distance meter (an example of a measuring device according to the present invention) 32 having an ultrasonic probe 30 and a corrector 34.
A water column 17 having the same height as the water column 16 is formed in front of the ultrasonic probe 30. The height of the water column 17 is measured using an ultrasonic distance meter 32, and a well-known equation of absorptivity is obtained. (See, for example, Japanese Patent Publication No. 3-69974), the radiant energy absorbed by the water column 16 can be obtained. In the corrector 34, the temperature obtained by the radiation thermometer 14 is corrected in consideration of the amount of radiant energy absorbed by the water column 16, and a signal representing the temperature obtained by this correction is input to the display 36. You. The display 36 performs emissivity correction and the like on the input signal, and displays the result as the surface temperature of the roll 12. In the above example, the two water columns 16 and 17 are formed.
7 may be used to form a single water column.

Using the above-mentioned temperature measuring device, the roll 12
FIG. 2 shows a measurement error when the surface temperature was measured. In order to determine the measurement error, a radiation thermometer serving as a reference thermometer capable of accurately measuring the surface temperature of the roll 12 is disposed upstream of the temperature measurement position of the temperature measurement device 10 in the rotation direction of the roll 12. The difference between the temperature measured by the thermometer and the temperature measured when the temperature of the water column was changed using the temperature measuring device 10 was determined as an error. The horizontal axis in FIG. 2 indicates the temperature of the water column, and the vertical axis indicates the difference between the temperature measured by the reference thermometer and the temperature measured by the temperature measurement device 10. Further, here, the temperature of the roll surface was measured while being heated to 750 ° C.

As shown in FIG. 2, when the temperature of the water column is set to 60 ° C. or more, the error becomes −20 ° C. or less, and the temperature can be measured accurately. The reason why the temperature measurement accuracy is improved when the temperature of the water column is 60 ° C. or higher is that when the temperature of the water column is 60 ° C. or higher, a boiling film is easily formed on the roll surface in contact with the water column, and this boiling film was formed. This is because the cooling capacity of the water column is reduced in some parts. [Second Embodiment] FIG. 3 shows the surface temperature of a steel sheet being cooled during conveyance, and a PLG 52 for measuring the speed of the steel sheet during conveyance and thickness information of the steel sheet to a temperature measuring device 10 (see FIG. 1). It is a schematic diagram which shows a mode that it measures using the temperature measurement apparatus to which P / C53 taken in from a high-order P / C (not shown) was added.

The table roller 5 is moved in the direction indicated by the arrow 40a.
The steel plate 40 being transported by the two cooling nozzles 4
The surface temperature of the steel sheet between the cooling nozzles 42 and 44 was measured using the temperature measuring device 10. In this measurement, the PLG 52 is set on the table roller 51, the compensator 34 determines the passing speed, the board thickness information is taken in from the upper P / C (not shown), and the passing speed provided in the compensator 34 is obtained. The optimum water temperature was determined from the relationship between the water temperature, the plate thickness, and the water temperature, and the controller 26 controlled the water temperature. In the corrector 34, a relational expression of a temperature measurement error, a plate thickness, a plate passing speed, and a water temperature is described. This relational expression can be obtained by the temperature measurement of the first embodiment.

FIG. 4 shows the measurement chart. The horizontal axis in FIG. 4 indicates the time from the start of the temperature measurement, and the vertical axis indicates the measured temperature and the distance measured by the ultrasonic distance meter. At the shape failure point of the steel plate 40, the distance cannot be measured and the surface temperature is measured low. However, when there was no influence of disturbance, the surface temperature could be measured stably with an error of ± 5 ° C.

[0017]

As described above, according to the present invention, the temperature of the water column formed between the object to be measured and the radiation thermometer is 6 degrees.
Since the temperature is 0 ° C. or higher, a boiling film is easily formed on the surface of the object to be measured in contact with the water column, and the temperature of the object can be measured accurately by suppressing the surface temperature of the object to be measured. Cooling unevenness is also reduced.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of a temperature measuring device according to the present invention.

FIG. 2 is a graph showing a measurement error when the temperature of a roll is measured using the temperature measuring device shown in FIG.

FIG. 3 is a schematic diagram showing a state in which the surface temperature of a steel sheet cooled during conveyance is measured using a temperature measuring device.

FIG. 4 is a graph showing a temperature measurement error when the temperature of the water column is set to 75 ° C. and the conveying speed of the steel sheet is changed.

[Explanation of symbols]

10 Temperature measurement device 12 rolls 14 Radiation thermometer 16 water column 18 Nozzle header 20 water supply 20a water 22 heater 26 Controller 32 ultrasonic rangefinder 40 steel plate

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-339649 (JP, A) JP-A-5-339965 (JP, A) JP-A-4-204220 (JP, A) JP-A-2- 168127 (JP, A) JP 3-69974 (JP, B2) (58) Field surveyed (Int. Cl. ⁷ , DB name) C21D 1/00-1/84 C21D 9/52-11/00 C21D 9/00-9 / 44,9 / 50 G01J 5/00-5/62

Claims (2)

(57) [Claims] 1. A water column is formed between a radiation thermometer for measuring a surface temperature of an object to be measured based on radiant energy radiated from the object to be measured and the object to be measured, and a radiation is emitted from the object to be measured. In the temperature measurement method of measuring the surface temperature of the object to be measured using the radiation thermometer while correcting the amount of radiant energy absorbed by the water column out of the radiated energy, in forming the water column, A temperature measuring method, wherein the temperature of a water column is 60 ° C. or higher. 2. A radiation thermometer for measuring a surface temperature of the device based on radiant energy radiated from the device, and a water column formed between the radiation thermometer and the device. A nozzle header in which the radiation thermometer is disposed, and a measuring device for measuring the height of the water column, and a water column is formed between the radiation thermometer and the object using the nozzle header. Then, while correcting the amount of radiant energy absorbed by the water column among the radiant energy radiated from the device under test based on the height of the water column, the surface temperature of the device under test is measured using the radiation thermometer. In a temperature measuring device for measuring water, water supply means for storing water and supplying the water to the nozzle header, heating means for heating the water stored in the water supply means, and water stored in the water supply means The temperature of the water will be within the specified range And a control means for controlling the heating means.