Liquid metal flow condition detection
AssigneeVesuvius Crucible Company
InventorsLawrence J. Heaslip, James D. Dorricott
Life of this patent
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Abstract
An apparatus and method for detecting the condition of the flow of liquid metal in or from a teeming vessel includes one or more sensors for detecting vibration caused by a flow of liquid metal in or from the teeming vessel and for outputting a sensor signal corresponding to mechanical and acoustic vibrations detected by the sensor. A signal processor receives the sensor signal and compares the sensor signal to a reference calibration signal and outputs a comparison signal. A logic unit receives the comparison signal and outputs a status signal indicative of the condition of the flow of the liquid metal in or from the teeming vessel which can be used to stop the flow of metal. The calibration signal can be static or may be dynamically updated.
Claims43
A method of detecting the condition of the flow of a liquid metal through an outlet from a teeming vessel, to indicate an undesired flow condition, the method comprising:
- a) generating a vibration calibration signal indicative of a desired flow condition of the liquid metal;
- b) sensing vibrations in the liquid metal flow;
- c) generating a sensor signal embodying information regarding the sensed vibrations;
- d) analyzing the sensor signal into a frequency band spectrum comprising multiple frequency bands;
- e) comparing at least one of the frequency bands with the calibration signal;
- and
- f) generating a status signal indicating an undesired flow condition in response to unacceptable differences between the sensor signal and the calibration signal.
A method of detecting an undesired flow condition in a flow of molten steel in a continuous casting process wherein molten steel is poured from successive teeming vessels through an outlet in each teeming vessel, the method comprising:
- a) commencing pouring of liquid steel from one of the successive teeming vessels through the teeming vessel outlet;
- b) generating a vessel-specific vibration calibration signal indicative of a desired flow condition of the liquid metal during the pouring of the liquid steel from the one teeming vessel;
- c) sensing vibrations in the liquid steel flow;
- d) generating a sensor signal embodying information regarding the sensed vibrations;
- e) comparing the sensor signal with the calibration signal;
- f) generating a status signal indicating an undesired flow condition in response to differences between the sensor signal and the calibration signal;
- g) replacing the one teeming vessel with a new teeming vessel charged with liquid steel;
- and
- h) repeating elements b) through f) with the new teeming vessel.
A method of detecting the condition of the flow of a liquid metal, optionally molten steel, through an outlet from a teeming vessel, to indicate an undesired flow condition, the method comprising:
- a) generating a vibration calibration signal indicative of a desired flow condition of the liquid metal;
- b) applying a standard deviation to the calibration signal whereby vibration intensities exceeding the standard deviation of the calibration signal indicate an undesired flow condition;
- c) sensing vibrations in the liquid metal flow;
- d) generating a sensor signal embodying information regarding the sensed vibrations;
- e) generating a status signal indicating an undesired flow condition in response to unacceptable differences between the sensor signal and the calibration signal.
A method of predicting an undesired condition in a liquid metal flow through an outlet from a molten metal pouring vessel, the method comprising the following elements:
- a) sensing flow-related perturbations in a physical parameter indicative of the undesired condition of the liquid metal flow to generate a sensed parameter signal;
- b) comparing the sensed parameter signal with a reference signal to generate a difference signal, the reference signal being generated prior to the sensed parameter signal;
- c) interpreting the difference signal to predict the presence of the undesired condition in the liquid metal outflow;
- and
- d) updating the reference signal with more recent data from the sensed parameter signal.
A method of predicting an undesired condition in a flow of liquid metal comprising the elements of:
- a) obtaining time-sequenced calibration spectra of a physical wave phenomenon indicative of the flow condition;
- b) calculating a predicted data spectrum of the physical wave phenomenon from the calibration spectra to indicate a flow condition at a future point in time;
- c) obtaining a current data spectrum at the future point in time;
- d) comparing the current data spectrum with the predicted data spectrum to provide spectral comparison data;
- e) processing the spectral comparison data to provide a status signal;
- f) storing the current data spectrum as the most recent entry in the sequence of calibration spectra;
- g) repeating elements b) through f).
Dependencies are inferred from the claim text.