Abstract: A method and apparatus for detecting electromagnetic noise generated by an arc and controlling a power supply that powers the arcs. In an embodiment of the invention, the apparatus includes an arc detection circuit and a power supply control circuit. The arc detection circuit includes an antenna and a single shot timer. Electromagnetic noise generated by an arc is received by the antenna and activates the single shot timer, which causes the power supply control circuit to interrupt the power supply powering the arc for a predetermined length of time. A microprocessor can be used together with, or instead of, the single shot timer.
Abstract: In a two-stage, electrostatic precipitator for extracting airborne particles, charged plates are electrically connected to each other and physically separated from each other by ferrite spacers so that an impedance of the spacers limits an amount of arc discharge current that will flow when an arc discharge occurs from one of the charged plates. Ferrite spacers can also be provided to electrically connect and physically separate grounded plates in the precipitator. In addition, aluminum spacers can be provided to adjust the impedance of the series of spacers through which an arc discharge current flows, so that the current is a minimum necessary amount for an arc detection circuit to detect.
July 14, 1998
Date of Patent:
August 1, 2000
Chi-Pai Ho, Ronald D. Voigts, Charles A. Haynes, James S. Blair
Abstract: The electrostatic air cleaning system is mounted in a duct of a residential or commercial heating and cooling system to remove particles from the circulating air. The electrostatic air cleaning system includes an air flow sensor which turns the air cleaner off in response to the lack of air flow through the air duct. An air flow sensor circuit connected to the electrostatic air cleaner includes a thermistor which detects the lack of air flow in the duct and provides a signal in response to lack of airflow. The signal from the sensor causes the power supply to the electrostatic air cleaner to be disconnected when there is insufficient air flow through the air duct. The air flow sensor circuit is configured so that power will continue to be supplied to the electrostatic air cleaner from the power supply when the sensor is disabled for a variety of reasons.
Abstract: A device for use in an electrostatic precipitator including an electrically insulating disk having a hole, which may be a venturi-shaped passage, for receiving a tie rod and an arrangement for supporting the tie rod in the hole so as to allow a fluid to flow through the hole between an inside surface of the hole and the tie rod. An air stream deflector may be mounted on the tie rod to provide further protection and help direct air flow. A recirculating flow system may also be provided to direct clean air through the venturi-shaped passage.
Abstract: An electronic air cleaner includes a housing having a fluid inlet and a fluid outlet for creating a fluid stream through the housing. Inside the housing is provided a set of first parallel conductive plates and a set of second parallel conductive plates, herein the first and second plates ar interspersed in an alternating fashion. An ionizer is provided on each of the second plates, and a source of negative high voltage is connected to each of the first plates. Particulate matter can be removed from the air stream in a method using the above-described electrostatic air cleaner.
Abstract: A filter apparatus for filtering chemical gases and odors from a fluid is disclosed. The filter apparatus includes a plurality of filter cartridges which each include a filter material, and a housing which fixes the filter cartridges relative to each other such that the filter cartridges form a W-shape with each filter cartridge forming a leg of the W-shape, to maximize the filtering efficiency of the filter apparatus while minimizing the pressure drop across the filter apparatus. A table top air cleaner is also disclosed,and includes a housing having an inlet opening and an outlet opening, an arrangement for drawing air through the inlet opening and for forcing air out of the outlet opening, and a plurality of filter cartridges which each include a filter material and which are fixed inside the housing relative to each other such that they form a W-shape.
Abstract: An apparatus for providing a uniform application of a functional coating to one or both sides of a moving metal strip includes an enclosed cabinet in which a corona discharge field is established between high voltage electrodes and the strip. The coating liquid and air are separately supplied under pressure to atomizing nozzles within the enclosure. The nozzles create a dense flat spray that is directed into the discharge field at an acute angle relative to the strip. The particles in the spray become charged and are attracted to the grounded strip, while those that are not charged are directed onto the strip by the force of the discharge field. The rate at which the coating liquid is supplied to the nozzles is varied in accordance with the speed of the strip to thereby obtain a uniform coating regardless of variations in strip speed or width.
Abstract: A power module for an electrostatic air cleaner in which an electronic power supply circuit and its components are enclosed within a relatively small modular housing having an AC voltage input in the form of plug-in blades particularly adapted to be inserted within a standard or conventional AC electrical outlet, and a cable for transmitting the high-voltage DC output from the housing to the air cleaner.
Abstract: A power supply with automatic arcing control and overload protection includes an electronic switch in an oscillator circuit with a primary winding of a step-up transformer. A high voltage, secondary winding of the transformer is loosely magnetically coupled to the primary winding. The frequency of oscillation of the oscillator circuit decreases as a load impedance across the secondary winding of the transformer decreases. In the case of arcing or shorting of an output circuit of the power supply the frequency of oscillation decreases below a pass band of the output circuit, thereby reducing the output current of the power supply.