Optical Cored Wire Feeding for Molten Metal Temperature Measurement
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Solution Overview
Problem
Existing methods for measuring the temperature of molten metal in electric arc furnaces using optical fibers face challenges such as devitrification, which leads to inaccurate readings due to varying devitrification rates and environmental conditions, and difficulties in maintaining a consistent immersion depth, especially in harsh industrial environments.
Innovation Solution
A method involving multiple feeding rates of optical cored wires over predetermined distances to control the feeding profile, ensuring the optical fiber remains un-devitrified and accurately measures molten metal temperature, with a two-speed feeding system to manage the immersion and consumption of the fiber, and a technique to determine the necessary length of dispensed wire based on vessel geometry and thermal conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the optical fiber is fed at a high rate to prevent devitrification, then measurement accuracy is improved, but the complexity of controlling the feeding rate increases
Solution Approach 1:
The patent applies dynamics by implementing a two-speed feeding system where the optical fiber is fed at different rates depending on its position and thermal exposure. The system dynamically adjusts between a first feeding rate when the fiber is being introduced and a second feeding rate when it reaches the measurement position, optimizing both accuracy and system simplicity.
Solution Approach 2:
The patent changes the feeding rate parameter based on the optical fiber's thermal exposure and position. By monitoring parameters such as the fiber's temperature and immersion depth, the system adjusts the feeding rate to maintain the fiber in a vitreous state while avoiding overly complex control mechanisms.
2Measurement precision
If the optical fiber is immersed deeper to ensure blackbody conditions, then measurement accuracy is improved, but the fiber consumption rate increases
Solution Approach 1:
The patent applies preliminary action by pre-positioning the optical fiber at an optimal immersion depth before measurement begins. The system calculates and sets the initial feeding rate and immersion depth to ensure blackbody conditions are achieved without excessive fiber consumption, preparing the measurement configuration in advance.
Solution Approach 2:
The patent optimizes the immersion depth parameter to balance measurement accuracy and fiber consumption. By adjusting the immersion depth to the minimum required for blackbody conditions and coordinating it with the feeding rate, the system achieves accurate measurements while minimizing fiber loss.
3Productivity
If the optical fiber is fed continuously to maintain constant temperature monitoring, then productivity is improved, but the difficulty of maintaining consistent immersion depth increases
Solution Approach 1:
The patent applies feedback by implementing a control system that monitors the optical fiber's position, immersion depth, and feeding rate in real-time. The system uses this feedback to continuously adjust the feeding rate and maintain consistent immersion depth, enabling continuous temperature monitoring while overcoming the difficulty of depth control.
Solution Approach 2:
The patent uses dynamics by making the feeding rate adjustable and responsive to real-time conditions. The system dynamically modifies the feeding rate based on the optical fiber's position and thermal state, allowing continuous monitoring while maintaining consistent immersion depth through active control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables continuous and accurate temperature detection during molten metal processing by maintaining the optical fiber in a vitreous state, reducing errors from devitrification and environmental factors, and adapting to varying conditions within the metallurgical vessel.
Implementation Method 1
the radiation light emitted from the molten metal at blackbody conditions is such that the intensity of the radiation using a photo-electric conversation element mounted on the opposite end of the immersed consumable optical fiber can be used to determine the temperature of the molten metal
Implementation Method 2
the radiation light emitted from the molten metal at blackbody conditions
Data Source
Figure 1~2
Figure 3a~3d
Figure 4
AI summary
A method for feeding a cored wire (6) into molten metal contained in a vessel comprises positioning the cored wire at a first position wherein a leading tip of the cored wire is proximate an entry point (35) of the vessel, the entry point being above a surface of the molten metal, the cored wire comprising an optical fiber and a cover laterally surrounding the optical fiber; feeding the cored wire at a first speed for a first duration from the first position to a second position wherein the leading tip (10) of the cored wire is immersed within the molten metal and lies within a measuring plane (20), such that a leading tip of the optical fiber projects from the cover and is exposed to the molten metal; and subsequently feeding the cored wire at a second speed for a second duration to take a first measurement of the molten metal.