Method and apparatus for monitoring temperature of blast furnace and temperature control system using temperature monitoring apparatus

• US 5,356,220 A
• Filed: 05/18/1993
• Issued: 10/18/1994
• Est. Priority Date: 05/29/1992
• Status: Expired due to Fees

• Current Assignee: Kawasaki Steel Corporation (JFE Holdings Incorporated)
• Original Assignee: Kawasaki Steel Corporation (JFE Holdings Incorporated)
• Inventors: Yanagisawa, Katsuhiko, Hironaga, Toshihiko, Iida, Osamu
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): BENNETT, GEORGE B
• Application Number:
  US08/063,035
• Time in Patent Office: 518 Days
• Field of Search: 374/116, 374/123, 374/124, 374/131, 374/137, 374/159, 374/161, 356/301, 250/227.14
• US Class Current: 374/161
• CPC Class Codes: C21B 7/24 Test rods or other checking devices
• CPC Class Codes: C21B 9/00 Stoves for heating the blast in blast furnaces
• CPC Class Codes: F27D 19/00 Arrangements of controlling devices
• CPC Class Codes: F27D 21/0014 Devices for monitoring temperature
• CPC Class Codes: F27D 21/04 Arrangements of indicators or alarms
• CPC Class Codes: G01K 11/32 using changes in transmittance, scattering or luminescence in optical fibres

Abstract

An optical fiber is laid in a spiral shape on a surface of an iron skin of a hot-air oven constituting a blast furnace facility, and one end of the optical fiber is connected to a temperature measuring apparatus. A temperature distribution of an optical fiber laid area is measured based on the intensity of Raman back scattering light of a light pulse transmitted into the optical fiber and based on a time interval until the Raman back scattering light returns to the transmission end of the optical fiber. The temperature distribution is displayed on a display screen to monitor the temperature distribution of the whole area of the iron skin of the hot-air oven to detect an abnormal condition thereof.

Claims

1. An apparatus for monitoring a temperature of a blast furnace facility, the apparatus comprising:

an optical fiber wound around and contacting an outside surface of said blast furnace facility;

temperature measuring means connected to a transmission end of said optical fiber, for measuring a temperature distribution of a measuring area of the outside surface of the blast furnace facility, the measuring area comprising portions of the outside surface of the blast furnace facility contacting the optical fiber, the temperature measuring means measuring a temperature distribution based on an intensity of Raman back scattering light from a light pulse transmitted into the optical fiber and further based on a time interval from the transmission of the light pulse until the Raman back scattering light returns to the transmission end of the optical fiber; and

display means for displaying the temperature distribution.

2. The apparatus of claim 1, wherein said optical fiber is laid on the outside surface of the blast furnace in a spiral shape.

3. The apparatus of claim 1, wherein said optical fiber has at least one surplus length portion, each surplus length portion being spaced away from the outside surface of the blast furnace facility.

4. The apparatus of claim 1, wherein said blast furnace facility is a blast furnace body.

5. The apparatus of claim 1, wherein said blast furnace facility is a hot-air oven.

6. The apparatus of claim 1, wherein the optical fiber is made of a high temperature resistant material.

7. The apparatus of claim 1, wherein a predetermined interval is spaced between each adjacent turn of said optical fiber.

8. The apparatus of claim 1, wherein the display means displays the temperature distribution of the outside surface of the blast furnace facility in a mosaic fashion, and the outside surface of the blast furnace facility is divided into a predetermined number of subareas.

9. The apparatus of claim 1, wherein the optical fiber comprises a fiber inserted into a tube, which is inserted into a guide pipe, wherein the guide pipe is wound around and welded to the outside surface of the blast furnace facility.

10. The apparatus of claim 1, wherein the outside surface of the blast furnace facility is a shell is substantially made of steel.

11. A temperature control system for a blast furnace facility comprising:

an optical fiber wound around and contacting an outside surface of said blast furnace facility;

temperature measuring means connected to a transmission end of said optical fiber for measuring a temperature distribution of a measuring area of the outside surface of the blast furnace facility, the measuring area comprising portions of the outside surface of the blast furnace facility contacting the optical fiber, the temperature measuring means measuring a temperature distribution based on an intensity of Raman back scattering light from a light pulse transmitted into the optical fiber and further based on a time interval from the transmission of the light pulse until the Raman back scattering light returns to the transmission end of the optical fiber;

water sprinkling control means for judging when the temperature distribution exceeds a predetermined set temperature and for opening a water spray valve; and

water sprinkling means for sprinkling water on the outside surface of the blast furnace facility, said water sprinkling control means controlling said water sprinkling means.