APPARATUS FOR MEASURING LEVEL OF MOLTEN METAL AND METHOD FOR MEASURING LEVEL OF MOLTEN METAL

• US 20140091221A1
• Filed: 12/09/2013
• Published: 04/03/2014
• Est. Priority Date: 06/24/2011
• Status: Active Grant

• Current Assignee: Nireco Corporation
• Original Assignee: Nireco Corporation
• Inventors: MATSUMOTO, Koichi, KATO, Yasumasa
• Granted Patent: US 9,322,696 B2
• Time in Patent Office: Days
• US Class Current: 250/357.1
• CPC Class Codes: B22D 11/16 Controlling or regulating processes or operations
• CPC Class Codes: B22D 11/186 by using electric, magnetic, sonic or ultrasonic means
• CPC Class Codes: B22D 2/003 for the level of the molten metal B22D11/181 and B22D11/201 take precedence; level indicators in general G01F23/00
• CPC Class Codes: G01F 23/284 Electromagnetic waves
• CPC Class Codes: G01F 23/2845 for discrete levels G01F23/288, G01F23/292 take precedence

Abstract

Provided is an apparatus for measuring a level of molten metal which has a simple structure and is highly robust against a change in level at a local portion of the surface of molten metal. The apparatus for measuring a level of molten metal according to a first aspect of the present invention is an apparatus which measures a level of molten metal in a mold. The apparatus includes an omnidirectional transmitting antenna; an omnidirectional receiving antenna; and a signal processor. The apparatus measures the level of molten metal in the mold using electromagnetic wave in ultra-high frequency range emitted into the mold by the omnidirectional transmitting antenna.

Claims

1. An apparatus for measuring a level of molten metal which measures a level of molten metal in a mold, comprising:

an omnidirectional transmitting antenna;

an omnidirectional receiving antenna; and

a signal processor,

wherein the apparatus measures the level of molten metal in the mold using electromagnetic wave in ultra-high frequency range emitted into the mold by the omnidirectional transmitting antenna.

2. An apparatus for measuring a level of molten metal according to claim 1, wherein the transmitting antenna and the receiving antenna are installed at a level which is higher than a surface of molten metal such that they are opposite each other in a plane which is parallel to the surface of molten metal.

3. An apparatus for measuring a level of molten metal according to claim 1, wherein the apparatus uses electromagnetic waves of two kinds of frequencies in ultra-high frequency range.

4. An apparatus for measuring a level of molten metal according to claim 1, wherein the apparatus measures the level of molten metal in the mold by detecting a phase difference between electromagnetic wave transmitted by the transmitting antenna and electromagnetic wave received by the receiving antenna.

5. An apparatus for measuring a level of molten metal according to claim 1, wherein the apparatus is constructed such that signal to be emitted by the transmitting antenna is modulated by a pseudo-random signal of frequency f₁, signal received by the receiving antenna is demodulated by a pseudo-random signal of frequency f₂ (f₂<

f₁) which has the identical pattern and measurement of the level of molten metal is performed in each measurement cycle period T_B which is determined by

T_B=N/(f_M1−

f_M2)

where N represents wave number in a period of the pseudo-random signals.

6. An apparatus for measuring a level of molten metal according to claim 5, wherein the apparatus alternately uses electromagnetic waves of two kinds of frequencies by switching for each measurement cycle period T_B.

7. A method for measuring a level of molten metal by which level of molten metal in a mold is measured, comprising the steps of

emitting electromagnetic wave in ultra-high frequency range by an omnidirectional transmitting antenna;

receiving electromagnetic wave reflected on a surface of molten metal by an omnidirectional receiving antenna; and

processing a signal of the electromagnetic wave emitted by the omnidirectional transmitting antenna and a signal of the electromagnetic wave received by the omnidirectional receiving antenna to obtain the level of molten metal.