Abstract: The exemplary system/apparatus can include an electrostatic precipitation apparatus for room ventilation, which can have a two-stage charging type electrostatic precipitator including an ionization section, a particle collection section and a power supply. The exemplary apparatus can include a constant-current control unit/arrangement interposed between the power supply and the ionization section. A sensing unit/arrangement can be interposed between the power supply and the particle collection section. A voltage step control unit/arrangement can receive the applied voltage value and current value from the sensing unit/arrangement for issuing a command to increase or decrease the predetermined voltage to prevent the particle collection section from anomalously discharging in response to an anomalous discharge.

Abstract: An air cleaner is provided according to an embodiment of the invention. The air cleaner includes a high voltage power supply configured to provide a high voltage to a collector cell and a shut-down circuit coupled to the high voltage power supply. The shut-down circuit is configured to monitor an electrical current supplied to the collector cell, remove electrical power to the collector cell if the electrical current exceeds a predetermined cell current threshold for a predetermined time period, and generate an indication if the electrical power is removed from the collector cell.

Abstract: An air treatment apparatus that includes an electrode assembly, a voltage supply, a current sensing device operably coupled to the electrode assembly, and a voltage control device coupled to the current sensing device and the voltage supply. The voltage control device is configured to regulate the level of voltage based on the level of current flowing through the current sensing device to maintain the voltage and current in the electrode assembly within designated ranges.

Abstract: A system and method for ionization detection in electrically enhanced air filtration systems is described. One embodiment includes a system for electrically enhanced air filtration, the system including an electrically enhanced filter having a filter and an ionizing electrode disposed on an upstream side of the filter; a control device connected to the electrically enhanced filter, wherein the control device can control the electrically enhanced filter; and an ionization detector, wherein the ionization detector is adjacent to the electrically enhanced filter and wherein the ionization detector is connected to the control device.

Abstract: An air purifier includes a housing, a high voltage power supply, a first electrode assembly in which a wire-like first electrode is either the only first electrode or, alternatively, is spaced sufficiently far from any other such first electrodes so as to avoid undesirable effects upon each other, and a second electrode assembly in which there are a plurality of blade-like second electrodes. The air purifier can be of the type in which air flows through the housing as a result of electro-kinetic effects. To increase air flow velocity, the voltage between first and second electrodes is relatively high, such as 23-50 kV, and the first and second electrodes are accordingly spaced apart a relatively great distance, such as at least 30 mm.

Abstract: An air cleaner is provided according to an embodiment of the invention. The air cleaner includes a high voltage power supply configured to provide a high voltage to a collector cell and a shut-down circuit coupled to the high voltage power supply. The shut-down circuit is configured to monitor an electrical current supplied to the collector cell, remove electrical power to the collector cell if the electrical current exceeds a predetermined cell current threshold for a predetermined time period, and generate an indication if the electrical power is removed from the collector cell.

Abstract: A system for detecting partial discharge activity in an electrostatic precipitator is provided. The system includes one or more sensors configured to receive and transmit signals representative of voltage or current behavior of the electrostatic precipitator. The system also includes a processor configured to receive the signals from the one or more sensors and configured for detecting one or more occurrences of partial discharge activity in the electrostatic precipitator.

Abstract: The energisation of an electrostatic precipitator is controlled in order to reduce arcing and/or back corona between the precipitator electrodes, using the precipitator current as a feedback parameter. A high speed switching device is used to control the energisation of the precipitator electrodes so that the precipitator current is regulated to a desired level with a response time that is significantly less than the arc generation time constant. The energisation is controlled so that the precipitator current is regulated to a predetermined value below the current level at which arcing occurs. The energisation response is proportional to the severity of the arcing, which can be based on the power and frequency of arcing. If back corona is detected, the energisation can also be controlled to reduce back corona.

Abstract: A compact electrostatic precipitator is designed specifically for use in connection with eliminating particles from crankcase emissions of a Diesel engine. Such emissions may carry solid soot particles as well as suspended oil droplets. The electrostatic precipitator has an electrode housing in which a high voltage electrode is mounted, and the emissions from the crankcase of a Diesel engine are passed across the electrode to an outlet. A high voltage power supply is mounted in a separate housing, and the output of the high voltage power supply is connected to the electrode only when the electrode housing and the power supply housing are properly mated, to thereby disable the high voltage connection to the electrode when the power supply housing is removed.

Abstract: An air purifier device includes a fan unit in an electrically conductive housing for drawing ambient air into the housing via an air inlet, and an electrically conductive dust-collecting member in the housing and disposed adjacent to an air outlet. A detecting unit is operable so as to provide a control signal in response to at least one of a change in electrical characteristics of the housing due to body contact therewith, and a change in electrical characteristics of the dust-collecting member due to excessive accumulation of dust thereon. A power control unit is operable to supply electric power to a negative ion generating unit such that a drive voltage is applied to an ionizing member of the negative ion generating unit, and is responsive to the control signal from the detecting unit to interrupt supply of the electric power to the negative ion generating unit.

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.

Abstract: Method for controlling, in case of flashover between electrodes in an electrostatic precipitator, the current supply to the electrodes from a controllable high-voltage direct-current source. The current supplied to the precipitator and the voltage between the electrodes of the precipitator are measured substantially continuously or at close intervals. After the flashover, the current supply to the electrodes of the precipitator is completely interrupted during a first time interval. During a second time interval directly following the first time interval, a current which is greater that the one supplied immediately before the flashover is supplied to the precipitator. Subsequently, the current is reduced to a value below the one prevailing immediately before the flashover.

Abstract: A system for controlling an electrostatic precipitator adapted to be powered by an alternating power source includes a regulator for regulating at least one precipitator operating parameter in response to at least one control signal, a measurement circuit coupled to the precipitator for providing measurement signals corresponding to at least precipitator secondary voltage and precipitator secondary current. A processor coupled to the measurement circuit and to the regulator generates the control signals.

Abstract: A dye-releasing mechanism is described which employs a nondiffusible dye-releasing compound having a dye or dye-precursor moiety attached thereto through a sulfonamido cleavage linkage so that a diffusible sulfonamide dye or dye-precursor will be released upon oxidation and subsequent alkaline hydrolysis of the compound.

Abstract: A multilayer color photographic material comprising a support having thereon at least a blue-sensitive silver halide emulsion containing a yellow coupler, a green-sensitive silver halide emulsion layer containing a magenta coupler, and a red-sensitive silver halide emulsion layer containing a cyan coupler, with the red-sensitive silver halide emulsion layer or a gelatin interlayer adjacent the red-sensitive silver halide emulsion layer containing a non-diffusible colored compound which, on coupling reaction with the oxidation product of a primary aromatic amino developing agent at development, can release a diffusible dye capable of being removed from the photographic layer.

Abstract: Positive color diffusion transfer images are produced by a process that employs light-sensitive photographic elements containing dye-releasing redox agents. The dye-releasing redox agents may be a sulfonamido compound or a hydroquinone derivative which are capable of cleaving to release a diffusible color-providing moiety. A preferred process involves the use of black-and-white developer compositions and comprises1. developing only a negative silver image in the imagewise exposed areas of the photographic element;2. fogging the residual silver halide;3. developing the residual silver halide in the fogged element to silver and concurrently releasing a diffusible dye or dye precurser in the non-image, fogged silver halide areas; and4. at least a portion of the diffusible dye or dye precurser compound diffusing to a dye image-receiving layer.

Abstract: A method for modifying vesicular images into non-scattering images is provided, which comprises opening the closed bubbles of the vesicular image to form an open-bore image by allowing at least one organic solvent which attacks the thermoplastic bubble walls of the vesicular image to act on the latter, optionally making the image wettable with a surfactant introducing the image substance into the open pores by treatment with a solution or dispersion of the image substance and, optionally removing any remaining gas bubbles or pores by heat or solvent treatment.