Hot Rolling Profile Measurement Using Dual-Frequency Electromagnetic Coils
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Solution Overview
Problem
Existing methods for measuring the transverse size of metal profiles during hot rolling, such as steel bars or tubes, face challenges including deviations in thickness due to mandrel eccentricity and localized thickness variations, and are often costly, sensitive to material conductivity, and require complex calibration and angular scanning.
Innovation Solution
A method using a sinusoidal current with two frequencies to generate an electromagnetic field with a desired profile, allowing for precise measurement of diameter and thickness through a transmission and reception element configuration that optimizes electromagnetic field conduction, independent of material conductivity and temperature, and capable of simultaneous measurement of local thickness at various angular positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radiographic methods with radioactive sources are used to measure transverse size during hot rolling, then measurement capability is provided, but high costs and safety problems arise from radioactive substance disposal
Solution Approach 1:
The patent replaces the radiographic measurement system (using radioactive gamma sources) with an electromagnetic induction system using coils and eddy currents. This substitution eliminates radioactive materials while maintaining the capability to measure transverse dimensions during hot rolling through non-contact electromagnetic sensing.
Solution Approach 2:
The patent employs ordinary electrical coils instead of expensive and hazardous radioactive sources. The electromagnetic measurement system uses conventional electrical components that are safer, cheaper, and do not require special disposal procedures, directly addressing the safety and cost issues of radioactive substance management.
2Measurement precision
If ultrasonic laser devices are used to measure transverse size, then thickness detection is enabled, but angular scanning and probe movement are required increasing device complexity
Solution Approach 1:
The patent replaces the mechanical ultrasonic laser system requiring angular scanning and probe movement with a stationary electromagnetic coil system. The measurement is achieved through electromagnetic induction without any mechanical movement or angular scanning, significantly simplifying the device structure while maintaining measurement capability.
Solution Approach 2:
The patent uses alternating current in the transmission coil to generate periodically varying magnetic fields, which induce eddy currents in the metal profile. This periodic electromagnetic action enables measurement without mechanical movement, replacing the continuous mechanical scanning required by ultrasonic laser devices.
3Measurement precision
If electromagnetic devices with parasitic currents are used, then transverse size measurement is provided, but measurement greatly depends on relative position of metal profile and sensor
Solution Approach 1:
The patent uses multiple coils positioned at different locations (transmission coils and reception coils arranged in specific geometries) to measure different aspects of the metal profile. By combining measurements from multiple localized electromagnetic fields, the system achieves position-independent measurement of transverse dimensions, overcoming the limitation of single-point electromagnetic sensors.
4Measurement precision
If electromagnetic devices with parasitic currents are used, then measurement is provided, but specific calibrations are required for different material conductivities
Solution Approach 1:
The patent employs a dual-coil electromagnetic system where the ratio of signals from transmission and reception coils provides a universal measurement approach. The system can measure transverse dimensions of metal profiles with different conductivities without requiring specific calibrations for each material, achieving versatility across different metal types through the electromagnetic induction principle.
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 method provides reliable, precise, and repeatable measurements of metal profile sizes, independent of alignment and material properties, enabling effective adjustment of rolling processes to achieve uniform products.
Implementation Method 1
power with a sinusoidal current having at least two frequencies, a transmission element having at least two sections distinct and spatially separated from each other, disposed along a nominal axis of feed of the metal profile and operating on the same nominal measurement of transverse size, and generate with the transmission element an electromagnetic field with a desired profile of the force lines
Implementation Method 2
detect a signal relating to the variations of the electromagnetic field due to the passage of the metal profile through the sections of the transmission element by means of a reception element having one or more sections distinct and spatially separated from each other and disposed along the nominal axis in a position comprised in the overall longitudinal bulk of the transmission element
Data Source
AI summary
A method for the hot measuring of a transverse size of a metal profile to obtain a diameter and/or a mean thickness includes providing power with a sinusoidal current having at least two frequencies, a transmission element having at least two sections distinct and spatially separated from each other and disposed along a nominal axis of feed of the metal profile, generating an electromagnetic field with a desired profile of the force lines, and detecting a signal relating to the variations of the electromagnetic field due to the passage of the metal profile through the sections of the transmission element using a reception element having one or more sections distinct and spatially separated from each other and disposed along the nominal axis in a position of the transmission element.