초록 ▼

A system for monitoring and controlling the level of liquid in a closed cainer includes a block for mounting at an upper end of the container, a lower level electrode for extending from the block vertically into the container, an upper level electrode for extending from the block vertically into the

A system for monitoring and controlling the level of liquid in a closed cainer includes a block for mounting at an upper end of the container, a lower level electrode for extending from the block vertically into the container, an upper level electrode for extending from the block vertically into the container and shorter than the lower level electrode, a valve for venting gas from the container, and a motor for driving the valve. Electric circuitry is responsive to liquid in the container rising to a free end of the upper level electrode to activate the motor to close the valve to increase gas pressure in the container to force lowering of the level of the liquid, and further electrical circuitry is responsive to the liquid in the container dropping below a free end of the lower level electrode to activate the motor to open the valve to vent the container and reduce gas pressure therein to permit rising of the liquid level.

대표청구항 ▼

[ What is claimed is:] [7.] A system for monitoring and controlling the level of liquid in a closed container in which a gas is bubbled up through the liquid, the system comprising:a block for mounting at an upper end of the container;a turn-on electrode for extending from said block vertically into

[ What is claimed is:] [7.] A system for monitoring and controlling the level of liquid in a closed container in which a gas is bubbled up through the liquid, the system comprising:a block for mounting at an upper end of the container;a turn-on electrode for extending from said block vertically into the container and of a first length;a common electrode for extending from said block vertically into the container and of said first length;a lower level electrode for extending from said block vertically into the container and of a second length shorter than said first length;an upper level electrode for extending from said block vertically into the container and of a third length shorter than said second length;a valve for venting the gas from the container;a motor for driving said valve;first means operative upon the liquid in the container reaching free ends of said turn-on electrode and said common electrode, to turn on said motor and activate said motor to turn on a first direction to move said valve toward an open position to vent the gas from the container;a second means operative upon the liquid in the container reaching a free end of said lower level electrode to turn off said motor leaving said valve in an open position; andthird means operative upon the liquid in the container reaching a free end of said upper level electrode, to turn on said motor and activate said motor to turn in a second direction to move said valve to a closed position, to allow gas pressure in the container to increase to push the level of the liquid in the container toward said lower level electrode free end;whereby upon the liquid in the container dropping from contact with said upper level electrode, said third means is operative to stop said motor; andwhereby upon the liquid in the container dropping from contact with said lower level electrode said second means is operative to start said motor and activate said motor to turn in said first direction to move said valve toward an open position to vent the gas from the container to reduce gas a pressure in the container, to permit the liquid therein to rise;wherein said first means comprises a resistor (R4); a transistor (Q3) turned on by said resistor (R4), current through said resistor (R4) being operative to flow through (R3), and through said transistor (Q3) to a switch (S1) which is operative for said turning on of said motor and said activating of said motor in a first direction to move said valve toward an open position.