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US 5,394,749 AGranted
Method and apparatus for detecting the position of fluid-fluid interfaces
AssigneeHughes Aircraft Company
InventorStephen A. Gabelich
Life of this patent
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AssigneeHughes Aircraft Company
InventorStephen A. Gabelich
Estimating the term…
Precise information is obtainable concerning the position of a fluid-fluid interface (28, 33), such as between a gas and a liquid or between liquids. Such information is important for the control and automation of molten metal refining processes. Specifically, in an electrolytic process for removing magnesium from molten aluminum, knowledge of the vertical position of an interface (33) between the electrolyte and the magnesium and an interface (28) between the electrolyte and the aluminum facilitates the automatic removal of the purified metals when drained or drawn from the furnace. Heat energy is conducted through a thermocouple-heater assembly 34 to a thermocouple (38) located at its tip (36). The equilibrium temperature at the thermocouple junction is dependent upon the heat loss through tip (36). When the tip comes in contact with a fluid of different thermal conductivity, as between molten matter (29) and electrolyte (30), the equilibrium temperature at tip (36) and, thus, of the thermocouple junction will change. This change in temperature is used to determine the level of the liquid-liquid interface between molten matter (29) and electrolyte (30). This information is used to determine when the drawing of further molten material from the furnace is to be terminated, so that aluminum purified in the refining process and previously drawn through an outlet (26) will not be contaminated.
In an electrochemical process for extracting magnesium from scrap aluminum in which the scrap aluminum in molten form is coupled to an anode and an electrolyte in molten form is coupled to a cathode, and in which a top layer of molten magnesium and a bottom layer of molten aluminum, sandwiching an intermediate layer of the molten electrolyte, are formed from the scrap aluminum, said aluminum, said electrolyte and said magnesium comprising molten layers, wherein the improvement comprises a method for monitoring the level of any of the molten layers at their interfaces, comprising the steps of:
Apparatus for detecting the position of an interface between fluids respectively having different heat transfer characteristics, comprising a sensor for sensing a change in the heat transfer between said sensor and said fluids at said interface, said fluids comprising a bottom layer of molten aluminum, an intermediate layer of molten electrolyte, and a top layer of molten magnesium, said fluids maintained in an electrolytic cell provided with a first outlet for drawing off molten magnesium and a second outlet for drawing off molten aluminum, said sensor comprising:
Dependencies are inferred from the claim text.