JPH03125936A - Apparatus of detecting temperature distribution in strip - Google Patents

Abstract

PURPOSE:To simply and accurately measure a temperature distribution in a material in rolling by coating a non-conducting material on the outer surface of a hollow roll and winding a thermocouple in parallel through the hollow and the small holes of the hollow roll without bringing the thermocouple into contact with the outer surface of the roll. CONSTITUTION:After plural small holes H arranged in a longitudinal direction are formed in a hollow roll (made of iron) 1, grooves are formed in a circumferential direction. Alumina 2 is thermally sprayed on the outer surface of the roll 1 by using LPPS to remove the electric conductivity of the outer surface. After a thermocouple composed of chromel 3 and alumel 4 is wound around the roll 1 through the hollow portion and the small holes and along the grooves of the roll 1 and the tips of the thermocouple are welded, a looseness is removed. The alumel 4 and the chromel 3 are insulated by using a glass wool 5 so as not to be brought into contact with the outer surface of the roll 1. After molybdenum 6 is thermally sprayed on the outer surface again, the outer surface is polished until the thermocouple is exposed. The output of the thermocouple is taken out by using a slip ring 7 to be fed to a recorder 8. The internal cooling of the roll 1 is conducted by using water. By bringing such a roll 1 into contact with a metal strip, the temperature distribution of a material below approximately 900 deg.C can be measured.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a measuring device for simply and accurately measuring the temperature distribution of a metal strip when rolling a material whose temperature is 900°C or less. In particular, it relates to a continuous temperature distribution detection device for a material when rolling a material such as iron or stainless steel with little scale or temper color on the surface of the strip at temperatures ranging from room temperature to about 500°C.

(Prior Art) Conventionally, many proposals have been made regarding methods of measuring the temperature of a strip. For example, as shown in "Theory and Practice of Sheet Rolling P, 274J (published by the Iron and Steel Institute of Japan), there is a radiation thermometer that measures the amount of radiant heat emitted from the surface of the object to be measured, and two types of metal wires. There are contact thermometers that use thermocouples that utilize thermoelectromotive force due to the Seebeck effect generated in a closed loop connected to

(Problem to be solved by the invention) A radiation thermometer is used to measure the temperature of a strip during hot rolling (temperature 60
0°C or higher). Since the emissivity is relatively stable during hot rolling, the temperature of the strip can be detected with high accuracy. However, it has drawbacks such as being susceptible to dust, poor maintainability, and being relatively expensive. In addition, when detecting a strip temperature of about 300°C, which is a plate temperature without a scale, this radiation thermometer is easily affected by the temper color, surface roughness (surface gloss), etc. of the strip surface. It is difficult to set the rate and it is not possible to measure the temperature of the strip.

Contact thermometers are used to discontinuously measure the temperature of strip materials from room temperature to approximately 800"C, and are not affected by emissivity, so they have good accuracy even in low temperature ranges. Temperature can be detected.However, when continuously measuring the temperature of a material, it is affected by frictional heat generation due to slip between the strip surface and the contact part, and the strip may be damaged. To protect the sensor if there is a change in shape,
The gap between the strip and the sensor needs to be controlled. Furthermore, it is necessary to take measures such as drainage to prevent coolant water from accumulating in a part of the sensor.

The inventors have already presented a strip temperature sensing device to solve these problems. This is a device that continuously measures the temperature of a running metal strip,
The hollow roll has small holes leading to the roll surface in the radial direction, and two types of metal wires forming a thermal lightning pair are guided through the small holes leading to the roll surface in the radial direction of the hollow roll, and are inserted into the non-conductive material. Two types of metal wires are buried so that a part of their outer circumferences are exposed and wound in the circumferential direction of a hollow roll, and the two types of metal wires wound in the circumferential direction are
This is a strip temperature detection device characterized in that it is configured to form a temperature measurement point by contacting a metal strip to be measured.

There is no problem with this temperature detection device when the measurement conditions are good, but when the measurement conditions are bad, for example, when the shape of the metal strip to be measured is quite bad, the temperature measurement roll and the strip may A state of no contact may occur, making measurement impossible or causing noise. Furthermore, there are also problems such as noise generation when the strip is not drained sufficiently.

The present invention relates to a measuring device for easily and accurately measuring the temperature distribution of a strip when rolling a material with a temperature of about 900°C or less. The present invention aims to provide an apparatus suitable for continuously detecting the temperature distribution of a strip when a small amount of material such as iron or stainless steel is rolled at a temperature from room temperature to about 500°C.

(Means for Solving the Problems) In the temperature distribution detection device of the present invention, two or more small holes are provided in the radial direction of a hollow roll that communicate with the roll surface. The outer periphery of the hollow roll is coated or sprayed with a non-conductive material to eliminate electrical conductivity on the roll surface. A thermocouple is wound through the hollow and small holes of the hollow roll in parallel to the outer periphery of the roll without contacting it. Furthermore, the outer periphery of the hollow roll is coated or sprayed with a conductive material. In addition, for example, it has a slip ring that sends the detected electromotive force to a recorder.

The hollow roll is made of a metal material such as iron or stainless steel, the thermocouple is made of chromel/alumel, chromel/constantan, etc., and the non-conductive material is made of a ceramic material such as alumina or zirconia. Molybdenum, iron, copper, aluminum, etc. are used as the conductive material.

Also, an FM rotational telemetry system may be used in place of the slip ring.

(Function) The present invention makes it possible to easily and accurately measure the material temperature distribution when rolling a material whose strip temperature is 900'C or less, and in particular, it is possible to easily and accurately measure the material temperature distribution when rolling a material whose strip temperature is 900'C or less. It is possible to continuously detect the temperature distribution of a strip when rolling a small amount of material such as iron or stainless steel at temperatures from room temperature to about 500''C.

(Example) FIG. 1 is a schematic diagram showing an example of a temperature measuring roll.

As shown in the drawings, the hollow roll 1 has an outer diameter lo.

Fin, inner diameter 80 mm, body length 400 mm S U S 304
(7) Created using hype as a material. Seven small holes H (diameter 4mm
), then open a space of 2 degrees to a depth of 0.0 mm in the circumferential direction.
A 25m+z groove was made using a lathe. At this time, the small hole H in contact with the outer periphery was tapered at an angle of 45 degrees and a depth of 0.5 degrees in the circumferential direction. After that, LP is applied to the outer periphery of this hollow roll.
Using PS, alumina 2 was thermally sprayed to a thickness of about 0.1 mm to eliminate electrical conductivity on the outer periphery of the roll.

Furthermore, chromel 3 and alumel 4 with wire diameter φ0.32mm
The thermocouple was wound around the outer periphery of the hollow roll along the aforementioned groove through the hollow part and small hole of the roll, and after welding the tip, the thermocouple was pulled so that there was no slack. At this time, glass wool 5 was used to insulate the exposed alumel and chromel so that they did not come into contact with each other or with the material of the hollow roll in the areas that were not thermally sprayed.

Using LPPS again, the outer periphery of the roll was coated with molybdenum 6.
21. After flame spraying, polishing was performed until the thermocouple appeared on the surface to eliminate unevenness in the length direction of the hollow roll.

Here, the reason why alumina is used as the non-conductive material is because the material is inexpensive, and the reason why molybdenum is used as the conductive material is because molybdenum is a substance with excellent wear resistance. In addition, the thickness of molybdenum is 0.1 to 0, considering cost, absolute value error of detected temperature, responsiveness, and polishability.
．． Approximately 5 fins is appropriate.

Further, the surface of the hollow roll was shot blasted to prevent slippage between the roll and the strip, and the surface roughness was finished to about 1 μsRa.

The output of the thermocouple was taken out using a slip ring 7 and sent to a recorder 8 equipped with a standard device.

Although not shown in the drawings, in the present invention, it is necessary to perform internal cooling so that the outer peripheral temperature of the hollow roll is lower than the temperature of the strip to be measured. Internal cooling of the roll was performed. Further, although not shown, the bearing portion that supports the hollow roll was internally cooled to prevent seizure due to heat (due to leakage of silicone grease).

FIG. 2 is a schematic diagram showing an example of implementation of the present invention. As shown in the drawing, the material 9 used in the experiment was a plain steel annealed coil with a plate thickness of 1.2 mm and a plate width of 350 mm. This coil is heated to a plate temperature of 500° C. by eight heating coils (not shown) of a high-frequency heating device IO located on the inlet side of the rolling mill (in the case of an inlet plate speed of 2 m/sin). Also,
The temperature distribution in the width direction of the material can be adjusted to a maximum of about 100° C. by adjusting the core position of each of the eight heating coils. In this experiment, the core position of each heating coil of the high-frequency heating device was adjusted so that the temperature at the center of the plate on the entry side of the rolling mill was 350°C and the temperature at the edge of the plate was 250°C.

Temperature measuring roll 12 is installed 1.5 steps above the pass line at a location approximately 80 cI11 away from the roll bite exit of the rolling mill (there is a deflector roll 11 at a location approximately 120 cm away from the roll bite exit of the rolling mill). did.

The rolling mill used was a work roll with a diameter of 13 mm and a diameter of 1B5 mm.
.

Backup roll 14 diameter φ480IIIm1 body length 4
This is a 4-high rolling mill with a size of 0.00. Rolling speed is 2 m-win
-'Reduction rate is 5-30%, forward tension is 10kgf--
2. The rear tension was 5 kgf*+am-'', and rolling was performed without lubrication.

Although the temperature of the material on the temperature measuring roll differs somewhat depending on rolling conditions, as a result of measurement with a contact type thermometer 15, it was 270 to 290°C at the center of the plate and 180 to 200°C at the edge of the plate. In addition, the work roll bender is O~7 ton/C.
The influence of the plate shape on the temperature accuracy of the temperature measuring roll was investigated by changing the shape of the plate on the exit side of the rolling mill from medium elongation to end elongation using HOCK operation.

FIG. 3 shows a comparison between the temperature of the material measured with a contact thermometer and the temperature of the material determined from the temperature measuring roll.

Regarding absolute temperature, the difference in detected temperatures increases as the temperature of the strip increases. Therefore, in order to accurately measure absolute temperature using the present invention, a calibration curve as shown in FIG. 3 may be created in advance.

Figure 4 shows the temperature difference in the strip width direction determined from a contact thermometer and the temperature distribution detection device of the present invention (temperature measuring roll).
A comparison of the temperature differences in the width direction of the strips determined from From FIG. 4, it can be seen that the present invention has an accuracy of detecting the temperature distribution (temperature deviation) of the strip within ±5°C.

It was also confirmed that no noise was generated in the output of the recorder. However, with regard to the temperature at locations where the material and the temperature measuring roll are intermittently in contact due to defects in the plate shape, it has been found that if the plate shape has a steepness of 2.0% or more, reliable data cannot be obtained. Ta. Countermeasures for such cases include increasing the height of the temperature-measuring roll to increase the contact area between the strip and the temperature-measuring roll, increasing the front tension, and pressing the strip onto the temperature-measuring roll. It is best to install a presser roll.

(Effects of the Invention) As described above, the device of the present invention can easily and accurately determine the temperature distribution of a strip when rolling a material with a temperature of 900°C or less, and especially the scale It is excellent for continuous temperature distribution detection of materials when rolling materials such as iron and stainless steel with little temper color at temperatures ranging from room temperature to approximately 500°C.

[Brief explanation of the drawing]

Figure 1 (a) is a schematic diagram showing an example of a temperature measuring roll, (b)
) is a partially enlarged explanatory diagram, FIG. 2 is a schematic diagram showing an example of implementation of the present invention, and FIG. 3 is a diagram showing the temperature of the material measured with a contact thermometer and the temperature measuring roll. Figure 4 shows a comparison between the temperature distribution of the material in the width direction of the material measured by a contact thermometer and the temperature distribution in the width direction of the material determined from the temperature measuring roll. FIG. 1: Hollow roll 2: Alumina 3: Chromel
4: Alumel 5 Niglass wool 6:
Molybdenum 7: Slip ring 8: Recorder 9: Material 10: High frequency heating device 11:
Deflector roll 12: Temperature measuring roll 13: Work roll I4: Backup roll 15: Contact thermometer H: Small hole Figure 1 (α) (1:1) Sub-agent

Claims (1)

[Claims] This device continuously measures the temperature distribution of a running metal strip, and includes two or more small holes communicating with the roll surface in the radial direction of a hollow roll, and the outer peripheral surface of the hollow roll is made of a non-conductive material. Two types of metal wires forming a thermocouple are guided in the radial direction of the hollow roll to form a thermocouple through small holes leading to the roll surface, so that a part of the outer periphery of the two types of metal wires is exposed in the non-conductive material. 2 which is wound in the circumferential direction of the buried hollow roll, and which is wound in the circumferential direction.
What is claimed is: 1. A strip temperature distribution detection device that detects the temperature distribution of a metal strip by bringing it into contact with a metal strip to be measured, the device being characterized by a metal wire of different types further coated with a conductive material.