Mold Powder Thickness Measurement Using Millimeter Wave Radar
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for measuring the thickness of mold powder layers in continuous casting are inaccurate, unreliable, and costly, particularly due to interference from electromagnetic fields and the need for expensive radar components.
Innovation Solution
A method using high-frequency (>85 GHz) and low-frequency (<13 GHz) frequency-modulated electromagnetic waves with narrow bandwidths for precise radar measurements of the mold powder and liquid metal levels, respectively, allowing for the use of conventional components and reducing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radar technology with large bandwidth (>20 GHz) is used to measure mold powder layer thickness, then the system can resolve the upper edge of the mold powder layer and liquid level, but the system becomes expensive and unreliable with different mold powders
Solution Approach 1:
The patent changes the frequency parameter from conventional radar frequencies (20-40 GHz) to millimeter wave frequencies (76-110 GHz). This parameter change enables sufficient resolution of the mold powder layer upper edge while allowing the use of standard frequency-modulated continuous wave (FMCW) radar technology, thereby improving both measurement precision and reliability across different mold powder types
Solution Approach 2:
The patent employs frequency-modulated continuous wave (FMCW) radar with periodic frequency sweeping. The radar signal frequency is modulated in a periodic triangular waveform, allowing for precise range measurement through frequency-time correlation. This periodic frequency modulation enables accurate thickness measurement while maintaining system reliability
2Ease of manufacture
If high-frequency (>85 GHz) electromagnetic waves are used for radar measurement, then conventional radar components can be used and costs are reduced, but the bandwidth must be limited to narrow range
Solution Approach 1:
The patent utilizes the high-frequency millimeter wave range (76-110 GHz) where standard FMCW radar components and signal processing techniques can be directly applied. This frequency parameter choice enables the use of conventional, cost-effective radar hardware while the narrow bandwidth requirement is naturally satisfied by the physical constraints of millimeter wave propagation and the specific measurement geometry
3Measurement precision
If electromagnetic or radiometric measuring systems are used to measure mold powder thickness, then the measurement can be performed, but electromagnetic fields from mold stirrers distort the signals or render them unusable
Solution Approach 1:
The patent uses millimeter wave radar signals as an intermediary measurement method that is insensitive to electromagnetic fields from mold stirrers. The high-frequency electromagnetic waves at 76-110 GHz penetrate through the mold powder layer and reflect from the liquid steel surface, providing measurement signals that are not distorted by the electromagnetic fields generated by submerged entry breathers or other electromagnetic stirring devices
Solution Approach 2:
By changing the measurement frequency to the millimeter wave range (76-110 GHz), the patent creates a measurement signal that is fundamentally different from the electromagnetic stirring frequencies, thereby avoiding interference. The high frequency allows the measurement signal to pass through the mold environment without being significantly affected by electromagnetic stirrers
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 enhances the accuracy and reliability of mold powder thickness measurements while reducing costs by using conventional radar components and minimizing electromagnetic interference.
Implementation Method 1
a radar antenna emitting the wave, the top edge of the mold powder and the top edge of the liquid metal reflecting the wave
Implementation Method 2
the top edge of the mold powder and the top edge of the liquid metal reflecting the wave
Implementation Method 3
electronics generating a frequency-modulated electromagnetic wave with frequencies > 85 GHz, a radar antenna emitting the wave... and the electronics measuring the height of the top edge of the mold powder sP
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to the thickness measurement of a layer of a casting powder (5) in a mold (3). The problem to be solved by the invention is that of increasing the reliability and the accuracy of the thickness measurement of the layer of the casting powder (5) in the mold (3). This problem is solved in that, during measurement of a height sP of a top edge of the layer of the casting powder (5), a first frequency-modulated electromagnetic wave (6, 6a) having frequencies > 85 GHz is generated, the first wave (6, 6a) is emitted, the top edge of the layer (5) reflects the first wave (6, 6a), and the height sP of the top edge of the layer is determined on the basis of a delay between the first emitted wave (6, 6a) and the first reflected wave. In addition, a height sM of a top edge of the liquid metal in the mold (3) is measured and the thickness d of the layer of the casting powder is determined.