Abstract: A device for detecting the surface level of molten metal in a mold, in which a thermo-sensitive magnetic element the relative magnetic permeability of which varies depending upon temperature is provided on an outer wall surface of the mold, and a coil connected to an A. C. power supply is mounted so as to leave a gap between the thermo-sensitive magnetic element and the coil, so that variation in electromagnetic coupling between the coil and the thermo-sensitive magnetic element due to temperature increase of the mold according to the rise of molten metal level can be detected.

Abstract: A device for detecting the level of the molten metal surface within a continuous casting mold. A detector element consisting of a body of a thermosensitive magnetic material, the magnetic properties of which vary in response to a temperature variation, is mounted at an appropriate position on a side wall of the continuous casting mold, and an electromagnetic coil for detecting the magnetic flux in the detector element is contained within a detector box mounted in a water jacket surrounding the mold at a position opposed to the detector element. The molten metal surface level within the mold is detected by detecting a change in the magnetic properties of the detector element by means of the electromagnetic coil. The detector box is detachably mounted in the water jacket, and water supply inlet and outlet means in the detector box guide cooling water through the detector box for cooling the electromagnetic coil within the detector box.

Abstract: The silo level indicating system includes a plurality of temperature indicating sensor units placed on the outside wall of a silo at vertically spaced positions. Each sensor unit and an adjacent portion of the surrounding sidewall is thermally insulated from the atmosphere so that a sensor unit is responsive to the temperature on the inside of the silo at the thermally insulated wall portion. The air within the silo above the level of material is at the same temperature. Thus, in a comparison of the temperature within the silo opposite each sensor unit to that of a reference sensor unit situated at the top of the silo, so as to be above the uppermost level of the material in the silo, a temperature differential between the reference sensor unit and a compared sensor unit indicates the presence of material at or above the compared sensor unit.

Abstract: The continuous casting of steel is supervised and controlled by measuring total heat flow and the ratio of upper to lower heat flow into the mold and causing these two valves directly or indirectly to be represented in a two dimensional field. The resulting operating point must remain within an empirically predetermined range for safe operation without skin rupture.

Abstract: This invention relates to the distribution, in free air, of the liquid phase of a cryogenic fluid which is stored under pressure.The apparatus consists of a phase-separator, a collecting tank for the liquid phase, an electrical system for controlling an electrical valve in order to hold the level in the tank constant, an adjusting member and distributor means.The invention is applicable to the inertizing of metallurgical furnaces or moulds, the protection of casting jets and molten metal, to the filling of containers, etc.

Abstract: A system for determining remotely the distance from the bottom of a storage tank to the liquid-vapor interface of the stored liquid utilizing a pair of solid state electrical sensing elements whose electrical resistance varies as a function of element heat dissipation capable of providing continuous extremely accurate digitally displayed measurement information referenced to the bottom of the tank even when the stored liquid and vapor are at the same temperature. The solid-state electrical interface sensing elements are affixed at the end of a vertically suspended motor driven cable disposed within the storage tank which is coupled to a DC pulse activated stepping motor and a master control circuit connecting the signal output of the sensing elements to the motor. The motor and cable system in conjunction with the control circuitry provide and drive the motor in stepping increments for continuously determining the liquid-vapor interface as referenced to the bottom of the storage tank.

Abstract: In apparatus for monitoring the liquid level in a tank which includes a resistance bridge supplied with d-c current having two bridge arms arranged inside the tank, one of which is electrically heated, with the output of the resistance bridge followed by a signal stage with a binary indication and by a current regulator for the heating current, and a testing arrangement for simulating a given filling level, the resistance bridge is supplied from a constant current source whose current is switched from one current value to another upon the operation of the testing device in order to preclude operating disturbances during the testing.

Abstract: The flow of liquid along a conduit or over a weir is measured by means of temperature-sensitive components positioned in vertically spaced relationship so that the number of components in contact with the liquid depends on the depth thereof. Thermal energy is supplied to the components in such manner that the components out of contact with the liquid are subjected to a substantial temperature increase. The components are periodically heated and examined after each period. Those of one temperature state are counted to indicate the depth of liquid and hence the flow rate.A count linearly related to the flow in a given conduit or weir can be achieved.

Abstract: A thermal type flowmeter comprising an elongated relatively small tubular probe, adapted to be inserted through a wall of a fluid containing vessel, contains an electrical resistance heater for heating the probe to a predetermined temperature. The electromotive force of a thermocouple, contained by the probe, indicates a voltage inversely related to the rate of heat dissipation from the probe to the surrounding fluid. With the temperature of the fluid being known or compensated for the rate of heat dissipation from the probe indicates the fluid flow rate.

Abstract: A switch includes a self-heating thermistor which has a certain resistance value when exposed to a medium of low thermal conductivity and a thermally conductive solid for movement into contact with the thermistor to lower its temperature and change its resistance. The solid is moved relative to the thermistor in response to any mechanical movement such as a float responding to liquid level or the closure of a door.

Abstract: A continuous metallurgical process such as electroslag refining or continuous casting is continuously monitored by surrounding the area of the melt with a hollow sleeve that contains a continuous helical passageway through which a coolant is continuously passed. The temperature of the coolant is continuously monitored at a plurality of points spaced apart axially of the sleeve, thereby to determine not the temperature of the adjacent metal or slag, but rather the quantity of heat transmitted by that adjacent metal or slag. In this way, the location of the solid metal, the molten metal and the slag, as well as other useful parameters, can be continuously monitored.

Abstract: An apparatus for determining and/or monitoring the amount of particulate material in an accumulator, which material enters the accumulator at a temperature above the ambient temperature, comprising an accumulator body for holding particulate material; an inlet means located in the upper portion of the accumulator body to allow the particulate material to enter the accumulator body; and a plurality of temperature sensing means located at points of differing height in the accumulator body below the inlet means.Improved methods for determining and/or monitoring the amount of particulate material entering an accumulator body through an inlet means at a temperature above the ambient are also disclosed.

Abstract: A level-sensing head is suspended from a capstan above a vessel by means of a flexible link which is wound around the capstan to raise or lower that head upon rotation thereof in one direction or the other. Depending upon the position of the sensing head relative to the level of a liquid or other flowable mass in the vessel, the head causes emission of either of two control signals triggering a pulse generator to step a motor, coupled with the capstan, in a sense tending to maintain that relative level between two narrow limits. The output of the pulse generator is also fed to recording equipment and/or to a digital comparator designed to establish a preselected level which may be modified from time to time by a programmer. The flexible link may serve as an electrical or fluidic transmission channel for control signals originating at the sensing head; with a floating sensing head such control signals can also be generated by a torsion monitor inserted between the motor shaft and the capstan.

Abstract: Measuring apparatus for determination of the level of a boundary layer between oil and water in a tank, comprising electrical sensing units distributed vertically in the tank and adapted to be responsive to the liquid and to deliver measuring signals to electrical measuring circuits with associated display devices for indicating and possibly recording the level. The sensing unit comprises thermo-couples each having a measuring junction part mounted in good thermal contact with a body of a material having good heat conducting properties, which body is adapted to be in good thermal contact with the surrounding liquid, and an electrical heating resistor being also in good thermal contact with the body and adapted to be supplied with a suitable electrical current.

Abstract: A pulsed thermal liquid level detector system is disclosed. The system includes a probe having a thermistor and a resistor disposed therein. The thermistor is thermally coupled to the resistor and is thermally coupled to a predetermined external surface of the probe by way of a material of low thermal resistance and capacity. The resistor is electrically coupled to a source of pulses which act to dissipate energy in the resistor thereby to heat the thermistor in accordance with the level of the pulses. The resistance of the thermistor varies in accordance with the temperature excursions induced by the pulses and within a range determined by the thermal capacity of the thermistor. The effective thermal capacity of the thermistor increases when the predetermined external surface is thermally coupled to a liquid which therefore reduces the resistance excursions of the thermistor.

Abstract: An improvement has been made to a cryogenic liquid level detection system of the type wherein a small electrical current is passed through a filament of superconducting material to generate a voltage proportional to the length of the filament above the liquid level. This improvement involves automatically interrupting the current flow immediately upon the growth of the normal resistance state of the filament above the liquid down to the liquid surface. Normally current flow is then reinitiated after a preset time interval. In this manner there is a minimum energy input to the liquid from the current and thus evaporative losses of the liquid are minimized.

Abstract: Level control apparatus for cyrogenic liquids having a cryogenic liquid. Means is provided for introducing cryogenic liquid into the chamber and outlet means is provided to permit removal of the cryogenic liquid from the chamber. Level sensing means is mounted on the flask and has a probe extending into the chamber so that it will come in contact with the cryogenic liquid when the cryogenic liquid reaches a predetermined level within the chamber. The probe includes a thermocouple with a resistor secured to the thermocouple for heating the thermocouple. When the resistor is in contact with the cryogenic liquid, the thermocouple remains cold and provides a signal of one type. When the resistor is uncovered by the cryogenic liquid and the thermocouple becomes hot, a signal of a different type is provided. The signals from the thermocouples are utilized for controlling the entrance of the cryogenic liquid into the chamber and to maintain the liquid level at a predetermined level within the chamber.

Abstract: A liquid level detecting device for vapour generators is characterized by a stack tube for connection to the vapour generator and preferably two separate side tubes in the form of loops each having an upper vapour inlet to the stack tube and a lower outlet disposed respectively at a low water level and a high water level. In use the loops fill with cooled condensate. When the water level moves past either of the cooling tube outlets the condition of that tube is disturbed, and the cooled water is displaced from one portion of the loop to another and steam occupies the previously cooled portion of the tube. The temperature change is sensed and used to give an alarm.