Electromagnetic Flow Detector With Envelope Circuit for Speed Variation
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Solution Overview
Problem
Existing electromagnetic flow meters for electrically conductive fluids, particularly dense and high-temperature liquids like liquid metals, face complexity in signal processing and are limited in measuring multi-dimensional flow conditions, especially in large volumes and high-speed environments.
Innovation Solution
An electromagnetic transducer with a metallic cylindrical core and primary and receiving coils, combined with envelope detector circuits and Schmitt triggers, simplifies signal processing to detect speed variations in electrically conductive fluids, capable of measuring both increases and decreases in fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex signal processing circuits are used in electromagnetic flow meters, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates unnecessary complex signal processing circuits from the electromagnetic flow meter. By using a simple envelope detector circuit with basic components (diode, capacitor, resistor) instead of complex processing systems, the patent achieves speed variation detection while significantly reducing device complexity.
Solution Approach 2:
The patent employs simple, inexpensive components for signal processing that can be easily replaced or adjusted. The envelope detector uses basic electronic components rather than expensive, complex circuitry, making the system simpler and more maintainable while still achieving the required measurement precision.
2Device complexity
If electromagnetic transducers are placed outside the flow, then device complexity is reduced, but measurement precision decreases
Solution Approach 1:
The patent nests the electromagnetic transducer within the flow path by placing it inside the conduit carrying the electrically conductive fluid. The transducer is positioned concentrically within the flow, allowing direct interaction with the fluid while maintaining a relatively simple structural arrangement.
3Reliability
If conventional electromagnetic flow meters are used for dense liquid metals, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent removes complex signal processing and measurement systems from the design, retaining only the essential electromagnetic transducer and simple envelope detector. This extraction of unnecessary complexity maintains reliability in harsh environments with dense liquid metals while significantly simplifying the overall system.
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
The detector provides simplified signal processing and accurate measurement of speed variations in dense, high-temperature fluids, overcoming the limitations of existing devices by allowing placement within the flow and reducing complexity.
Implementation Method 1
The primary 3 and secondary 4 coils are wound around the tube 2. An alternating electric current is imposed in the primary coil. The circulation of this current creates an external magnetic field B in the environment close to the primary coil, according to the Maxwell - Ampere equation
Implementation Method 2
the conductivity σ of the fluid causes the development of currents (electric current density J) under the action of the displacement speed u combined with the external magnetic field B: This happens even in the absence of an electric field E. Current densities J u are the source of a magnetic field B u . This field B u distorts the external field B.
Implementation Method 3
at least one envelope detector circuit connected to the receiving coil, comprising at least one diode and a load in electrical series with the diode, the load consisting of a capacitor and an electrical resistor
Data Source
Figure 1~2A
Figure 3~5A
Figure 5B~6
AI summary
Detector for variation in the speed of a flow of an electrically conductive fluid, comprising an electromagnetic transducer. The invention relates to a detector for variation in the speed of a flow of an electrically conductive fluid, comprising: - an electromagnetic transducer (10), comprising: a metallic cylindrical tube (2) forming a core with high magnetic permeability, an electric coil (3), called the primary coil, wound around the tube and intended to be electrically powered with direct current, or a permanent magnet arranged around the tube, at least one electric coil (4), called the receiver coil, wound around the tube while being adjacent to the primary coil or to the permanent magnet, - at least one envelope detector circuit (7) connected to the receiver coil, comprising at least one diode (8; 8.1, 8.2) and a load (9; 9.1, 9.2) in electrical series with the diode, the load consisting of a capacitor (90; 90.1, 90.2), and an electrical resistance (91; 91.1, 91.2).