Method and apparatus for controlling the heat transfer of liquid coolant in continuous casting
AssigneeAluminum Company of America
InventorHo Yu
Life of this patent
Estimating the term…
Abstract
A method for continuously monitoring and/or controlling the cooling capacity of a liquid coolant containing gas bubbles. The method comprising the steps of: (a) measuring the size and number density of the gas bubbles it he liquid coolant by use of a sensor means to infer a heat transfer characteristic of the liquid coolant; and (b) varying the amount of gas that is being mixed with the liquid coolant so that the inferred heat transfer characteristic is within a predetermined range.
Claims71
A method for continuously controlling the heat exchange capacity of a liquid containing gas bubbles, said method comprising the steps of:
- detecting the relative density of said bubbles;
- comparing said relative density to a reference density range;
- and
- varying the amount of gas in said liquid so that said relative density is within said reference range.
A method for continuously monitoring and controlling the heat exchange capacity of a liquid containing gas bubbles mixed therein, said method comprising the steps of:
- generating a signal which is related to the number density of said bubbles;
- and
- comparing said generated signal to a reference signal.
A method for continuously casting metal ingots using a liquid coolant, said method comprising the steps of:
- casting molten metal into an open-ended mold used to form an ingot emerging therefrom;
- providing a liquid coolant;
- mixing a gas with said liquid so that said liquid contains gas bubbles;
- detecting the relative density of said bubbles;
- comparing said relative density to a reference range;
- when said relative density is outside said reference range, varying the relative amount of gas that is being mixed with said liquid to bring said relative density within said reference range;
- and
- applying said liquid to said ingot emerging from said mold to effect at least partial solidification of said molten metal.
A method for continuously casting metal ingots using a liquid coolant, said method comprising the steps of:
- casting molten metal into an open-ended mold to form an ingot which emerges therefrom;
- providing a liquid for cooling said ingot;
- mixing a gas with said liquid coolant so that said liquid contains gas bubbles;
- passing light through said liquid onto a light sensing device;
- detecting the relative density of bubbles that fall within a reference range from the scattering of said light and generating a signal therefrom;
- comparing said number density to a reference signal;
- when said generated signal is outside said reference range, varying the relative amount of gas that is being mixed with said liquid coolant to bring said generated signal within said reference range;
- and
- varying said reference range from a first range that is used during the first stages of casting to a second range that is used when said emerging ingot is in a second stage;
- and
- applying said liquid to said ingot emerging from said mold to effect at least partial solidification of the molten metal.
A method for continuously casting metal ingots using a liquid coolant, said method comprising the steps of:
- casting molten metal into an open-ended mold used to form an ingot which emerges therefrom;
- providing a liquid coolant;
- mixing a gas with said liquid so that said liquid coolant contains gas bubbles;
- generating a signal which is related to the relative density of said bubbles;
- and
- passing light through said liquid coolant onto a light sensing device to determine the relative density of said liquid coolant;
- comparing said generated signal to a reference signal;
- when said generated signal is outside said reference range, varying the relative amount of gas that is being mixed with said liquid coolant to bring said generated signal is within said reference range;
- varying said reference range from a first range that is used during the initial stages of casting when said ingot is in a startup state to a second range that is used when said emerging ingot is in a steady state;
- and
- applying said liquid to said ingot emerging from said mold to effect at least partial solidification of the molten metal.
An improved method for cooling the surface of metal, said method comprising the steps of:
- mixing gas into a liquid coolant to form an improved liquid coolant and applying said coolant to said metal, said gas forming bubbles which act to retard the rate of heat extraction from said metal;
- continually detecting the relative density of said bubbles within a reference range;
- comparing said number density to a reference range;
- when said generated signal is outside said reference range, varying the relative amount of gas that is being mixed with said liquid to bring said number density within said reference range.
An improved method for the continuous casting of molten metal into an ingot in which a liquid coolant is applied to an open-ended mold to effectuate at least partial solidification of the molten metal therein, said liquid coolant containing gas that forms bubbles which act to retard the rate of heat extraction from said ingot, the improvement comprising the steps of:
- detecting the relative density of said bubbles within a size range;
- and
- comparing said relative density to a reference density number;
- and
- varying the amount of gas that is being mixed with said liquid so that said relative density is within said reference range.
An apparatus for continuously monitoring and controlling the heat exchange capacity of a liquid containing gas bubbles, said apparatus comprising:
- a detecting means for detecting the relative density of said bubbles;
- and
- a varying means for varying the amount of gas dissolved within said liquid coolant if said number density is outside a reference range.
An apparatus for casting a melt into an ingot, said apparatus comprising:
- an open-ended mold for casting a continuously or semicontinuously cast ingot;
- an application means for applying liquid to said ingot to effect at least partial solidification thereof, said liquid containing a gas bubbles which retard the rate of heat extraction from said ingot;
- a detecting means for detecting the density of said bubbles to infer the heat transfer characteristics of said liquid coolant;
- a varying means for varying the amount of gas dissolved within said liquid coolant if said inferred heat transfer characteristic is outside a reference range;
- and
- a means for applying said liquid coolant to said ingot emerging from said mold to effect at least partial solidification of the molten metal.
An apparatus for casting a melt into a rectangular ingot possessing a high width to thickness ratio, said apparatus comprising:
- an open-ended mold for casting a continuously or semicontinuously cast ingot, said mold possessing a high width to thickness ratio, said mold holding a reservoir of melt;
- an application means for applying liquid to said mold to effect at least partial solidification of the molten metal therein, said liquid containing a gas bubbles mixed therein;
- a detecting means for detecting the relative density of said bubbles within a size range;
- and
- a comparing means for comparing said relative density to a reference range;
- when said relative density is outside said reference range, varying the relative amount of gas that is being mixed with said liquid to bring said relative density within said reference range.
An apparatus for casting a melt into an ingot, said apparatus comprising:
- an open-ended mold for casting molten metal into a continuously or semicontinuously cast ingot;
- a plurality of mixing chambers for mixing pressurized gas into a liquid to form an improved liquid, each of said plurality of mixing chambers being independently operable and capable of mixing a different amount of said gas into said liquid;
- a plurality of application means for applying said improved liquid to said mold to effect at least partial solidification of the molten metal therein, said improved liquid containing gas bubbles which form an insulation layer on the surface of said ingot and act to retard the rate of heat extraction from said ingot, each of said plurality of application means being independently operable and capable of applying said improved liquid to said mold to create zones containing different insulation layers;
- a plurality of detecting means positioned for detecting the relative density of said bubbles flowing into a different application means;
- a plurality of comparing means, each of said plurality of control means capable of comparing said relative density to a different reference density range;
- a plurality of varying means for varying the amount of gas that is being mixed with said liquid to bring each said relative density within its said reference range;
- and
- a means for applying said liquid coolant to said ingot emerging from said mold to effect at least partial solidification of the molten metal.
A method for continuously monitoring and controlling the heat exchange capacity of a liquid-gas mixture, said method comprising the steps of:
- mixing gas with a liquid to form a liquid-gas mixture;
- detecting the relative density of gas bubbles in said liquid-gas mixture that are within a reference range;
- and
- comparing said relative density to a reference density range;
- and
- varying the amount of gas that is being mixed with said liquid so that said relative density is within said reference range.
An apparatus for comparing the heat exchange capacity of a liquid containing gas bubbles, said apparatus comprising:
- a generating means for generating a signal related to the relative density of said bubbles;
- a comparing means for comparing said generated signal to a reference signal;
- and a varying means for varying the amount of gas in said liquid
A method for continuously controlling the heat exchange capacity of a gas containing droplets of liquid, said method comprising the steps of:
- detecting the relative density of said droplets;
- comparing said relative density to a reference density range;
- and
- varying the amount of gas in said liquid so that said relative density is within said reference range.
A method for continuously monitoring the heat exchange capacity of a gas containing droplets of liquid mixed therein, said method comprising the steps of:
- generating a signal which is related to the number density of said droplets;
- and
- comparing said generated signal to a reference signal.
A method for continuously monitoring and controlling the heat exchange capacity of a gas containing droplets of liquid mixed therein, said method comprising the steps of:
- generating a signal which is related to the number density of said droplets;
- comparing said generated signal to a reference signal;
- and
- varying the relative amount of gas that is being mixed with said liquid to bring said generated signal closer to said reference signal when said generated signal is outside said reference range.
Dependencies are inferred from the claim text.