Abstract: The method for monitoring the signal quality of an electrostatic precipitator comprises measuring in real time at least one feature of a primary electric power sent to a transformer of the electrostatic precipitator and/or at least one feature of a secondary electric power sent to the collecting electrodes and discharge electrodes of the electrostatic precipitator, elaborating the at least a measured feature generating an information indicative of the electrostatic precipitation signal quality, providing the information.

Abstract: In a charging time period T1, a dry electrostatic precipitator outputs DCON that is a current for charging a collection target object from a high voltage power supply. Subsequently, in a second period of time T2-2 after a first period of time T2-1 passes from a time that a charging pause time period T2 starts, the dry electrostatic precipitator outputs DCBC that is a current that is less than DCON and is greater than a current in the first period of time T2-1, from the high voltage power supply.

Abstract: Embodiments of the present disclosure may suppress conduction between an anode and a cathode caused by condensed water in an oil removal apparatus in which oil particles are collected in a filter disposed between the anode and the cathode. An insulating layer may be sandwiched either between the filter and at least one of the anode and the cathode of the bipolar electrode, or within the filter so as to extend in a flow direction of blow-by gas, and may have an insulating property so as to prevent condensed water generated when moisture in the blow-by gas condenses, from connecting the anode and the cathode of the bipolar electrode.

Abstract: A wireless power transmission circuit for wirelessly transmitting line frequency sinusoidal AC power to a load where the line frequency ripple filter of conventional circuits is eliminated and a DC-to-AC inverter is replaced by a simple polarity inversion circuit. The envelope of the high frequency AC on the AC line frequency source side is not constant but varies continuously in a half-sinusoidal fashion at the line frequency. Wireless transmission occurs only with a half-sinusoidal, constantly varying envelope, not the constant amplitude envelope of prior art. High frequency rectification and high frequency ripple filtering occurs as in the prior art but the ripple filter time constant is selected so that resulting waveform is an accurate replica of the rectified line frequency voltage present on the transmitter side. A polarity inversion stage replaces the DC-to-AC inverter of conventional art to generate the line frequency AC.

Abstract: Provided is a method of controlling the operation of an electrostatic precipitator (6) using a control strategy for a power to be applied between at least one collecting electrode (28) and at least one discharge electrode (26). The control strategy is directed to controlling, directly or indirectly, a power range and/or a power ramping rate. As such, the temperature of a process gas is measured. When the control strategy controls a power range, a power range is selected based on the measured temperature, an upper limit value of the power range being lower at a high temperature of said process gas, than at a low temperature. When the control strategy controls a power ramping rate, a power ramping rate is selected based on the measured temperature, a power ramping rate being lower at a high process gas temperature, than at a low process gas temperature.

Abstract: The method of modeling fly ash collection efficiency in wire-duct electrostatic precipitators provides for the optimization of fly ash collection through the generation of numerical solutions to the electrostatic and electrodynamic equations associated with the particular geometry of the wire-duct electrostatic precipitator. Particularly, the solutions are developed through use of the finite element method and a modified method of characteristics.

Abstract: A method for monitoring operation of a rapper in an electrostatic precipitator using a rapper control system is described. The method includes determining model electrical characteristics of the rapper. The model electrical characteristics of the rapper correspond to model mechanical operating characteristics of the rapper. The method also includes storing data corresponding to the model electrical characteristics and the model mechanical operating characteristics of the rapper, determining actual electrical characteristics of the rapper, and comparing the actual electrical characteristics of the rapper to the stored model electrical characteristics to determine actual mechanical operating characteristics of the rapper.

Abstract: A method and a system for controlling dust particle emissions from an electrostatic precipitator (1), which has a first and a second bus-section (16, 20), are provided. Dust particle emissions are controlled by observing that a rapping event of the first bus-section (16) is about to be initiated, verifying, before allowing the rapping event of the first bus-section (16) to be initiated, that the second bus-section (20) is ready to receive the dust particles to be released during the rapping event of the first bus-section (16), and then initiating, after verification, the rapping event of the first bus-section (16).

Abstract: A system includes an electrostatic precipitator, an electromagnetic sensor and a processor to locate spark locations. The electromagnetic sensor is used at various locations of the electrostatic precipitator to obtain data and process the same for locating sparks in electrostatic precipitators.

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: The aim of the invention is to be able to adapt an item of visualization or optimization software with the least possible amount of effort made on any electrostatic filter configurations. To this end, the invention provides that the electrostatic filter, the high-voltage supply units, and the auxiliary functional units can be used by the software modules in the server component as objects with characteristic features and with characteristic methods, that are capable of being accessed as information, which only exists in the server component, for the client modules via data interfaces.

Abstract: The frequency of a cyclically varying voltage, (fv), is made equal to or higher than the frequency of a streamer discharge, (fs), thereby making it possible to reduce the discharge delay time which is caused in a single streamer discharge.

Abstract: The invention relates to a pulse generating system for generating high voltage pulses to energize an electrostatic precipitator (10), the system including: a first power supply (1) and a second power supply (2), where said second power supply (2) is arranged to pre-charge said electrostatic precipitator (10) to a DC voltage; a storage capacitor (7) and a series inductance; a switching device (5) coupled in parallel with an anti-parallel rectifier device (6); and wherein the system is arranged to be coupled to the electrostatic precipitator. The invention relates to provide such a pulse generating system with enhanced efficiency compared to present pulse generating systems and with enhanced protection of the components of the system in case of sparks in the electrostatic precipitator (10). This is achieved, when the switching device (5) of the system has turn-off capability and when the system includes a clamping circuit (11-13; 60-67).

Abstract: A method for handling a fluid may be incorporated into the operation of, for example, a corona discharge device and an electric power supply. Such a corona discharge device typically includes at least one corona discharge electrode and at least one collector electrode positioned proximate each other so as to provide a total inter-electrode capacitance within a predetermined range. The electric power supply is connected to supply an electric power signal to said corona discharge and collector electrodes so as to cause a corona current to flow between the corona discharge and collector electrodes. A relationship between alternating and direct (or constant, non-time varying) components of the voltage may be expressed as (Vac/Vdc)?(Iac/Idc).

Abstract: A fan cooling system for use with an electronic apparatus having a fan for providing a cooling draft and adapted to remove draft-borne dust includes: an input module for receiving a control instruction; a programmable logic module electrically connected to the input module and adapted to validate the control instruction received by the input module and output a logic result in accordance with the control instruction; and an electrostatic module comprising an electrostatic filtering unit and an electrostatic controlling unit electrically connected to the electrostatic filtering unit and the programmable logic module, wherein the electrostatic filtering unit adjoins the fan to take the cooling draft, and the electrostatic controlling unit applies static electricity to the electrostatic filtering unit in accordance with the logic result sent from the programmable logic module and thus enables the electrostatic filtering unit to electrostatically adsorb draft-borne dust.

Abstract: A method for the acceleration of an electromagnetic rapper, particularly for an electrostatic precipitator, which includes a metal cylinder as a hammer, an electrical coil for lifting the metal cylinder and a coil energizer for energizing the electrical coil. For cleaning a surface the metal cylinder is lifted by an initial electrical pulse generated by the coil energizer. The coil energizer supplies the electrical coil with an additional electrical pulse so that the metal cylinder is accelerated when it has reached the maximum point of its trajectory.

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: A gas separation apparatus using electrostatic precipitators and mechanical rappers is enhanced by the addition of an opposite polarity refreshing power supply and a switching arrangement. The switching components selectively disconnect the primary power supply and connect the refreshing power supply to the electrostatic precipitator, causing an electrical impulse in the precipitator sufficient to dislodge precipitate from the collector plates. In one embodiment, an RC filter is further provided to control the impulse and reduce the burden that would otherwise be placed upon the refreshing power supply. In a second embodiment, a pair of SCR strings serve as the switches. Cleaning power is delivered from a capacitor through one of the SCR strings using a resonant circuit, the resonance which causes the SCR string to commutate off after the impulse has been delivered.

Abstract: Provided are a hollow inner electrode constituted by an electrically conductive filter capable of capturing particulates, a cylindrical outer electrode circumferentially surrounding the electrode, a housing incorporated in a flow passage of exhaust and accommodating the electrodes and, a temperature sensor for detecting temperature of the exhaust and an electric discharge controller for controlling electric power to be distributed to the electrodes and on the basis of a detected value of the temperature sensor. When the temperature of the exhaust obtained by the temperature sensor is lowered, electric power necessary for generation of discharge plasma is distributed by the discharge controller to the electrodes and, thereby oxidizing the particulates captured by the electrode to reduce electricity consumption.

Abstract: An air cleaner including a constant current power supply is provided according to an embodiment of the invention. The air cleaner includes a collector cell and a constant current power supply coupled to the collector cell. The constant current power supply is configured to maintain a substantially constant electrical current output to the collector cell, compare an output voltage of the constant current power supply to an upper voltage threshold VU and to a lower voltage threshold VL, and shut down the constant current power supply if the output voltage is not between the upper voltage threshold VU and the lower voltage threshold VL.

Abstract: Disclosed is an apparatus and method for controlling an air cleaning. The apparatus includes an air cleaning element, an AC high-voltage generator and a control unit. The air cleaning element generates negative ions and ozone using plasma discharge, and cleans indoor air using the negative ions and ozone. The AC high-voltage generator generates an AC high-voltage, and applies the AC high-voltage to the air cleaning element. The control unit varies at least one of the AC voltage and AC frequency applied to the air cleaning element by the AC high-voltage generator depending on a state of indoor air being cleaned using the air cleaning element. Therefore, it is possible to effectively generate negative ions while minimizing ozone generation to an acceptable level depending on a state of indoor air, thereby increasing air cleaning performance so as to sterilize and clean contaminants more efficiently.

Abstract: An electrostatic precipitator having a plurality of electrostatic precipitation units positioned within the electrostatic precipitator. Each of the electrostatic precipitation units includes a plurality of negative wire electrodes and a plurality of positive electrode plates. The electrostatic precipitation units are arranged such that spacing between the negative wire electrodes of a first electrostatic precipitation unit is a first distance apart, and spacing between the negative wire electrodes of additional electrostatic precipitation units is less than the spacing between the negative wire electrodes of the first electrostatic precipitation unit. Moreover, a variable voltage is applied to the each of the electrostatic precipitation units between the positive electrode plates and the negative wire electrodes so as to cause particles in the exhaust gas to adhere to the positive electrode plates.

Abstract: An air purifier for removing particles in air includes an outer casing, and an ionizer module. The ionizer module includes a power unit and an ionizing electrode unit, electrically connected to the power unit. The ionizing electrode unit includes a first electrode set as an electrode terminal disposed within the outer casing at an air inlet, a second electrode set disposed within the outer casing at an air outlet, and a third electrode set disposed within the outer casing at a position between the first and second electrode set, wherein a voltage of the third electrode set is higher than a voltage of the first electrode set for drawing the air from the first electrode set to the second electrode set via the second electrode set while dirt particles contained in the air is trapped on the second and the third electrode sets.

Abstract: A device for handling a fluid includes a corona discharge device and an electric power supply. The corona discharge device includes at least one corona discharge electrode and at least one collector electrode positioned proximate each other so as to provide a total inter-electrode capacitance within a predetermined range. The electric power supply is connected to supply an electric power signal to said corona discharge and collector electrodes so as to cause a corona current to flow between the corona discharge and collector electrodes. An amplitude of an alternating component of the voltage of the electric power signal generated is no greater than one-tenth that of an amplitude of a constant component of the voltage of the electric power signal.

Abstract: A gas separation apparatus using electrostatic precipitators and mechanical rappers is enhanced by the addition of an opposite polarity refreshing power supply and a switching arrangement. The switching components selectively disconnect the primary power supply and connect the refreshing power supply to the electrostatic precipitator, causing an electrical impulse in the precipitator sufficient to dislodge precipitate from the collector plates. An RC filter is further provided to control the impulse and reduce the burden that would otherwise be placed upon the refreshing power supply. The novel separation apparatus and technique offer particular synergy when applied to the effluent stream from a coal-fired electric power plant or other similar gas streams.

Abstract: A gas separation apparatus which uses electrostatic precipitators and a DC power supply is controlled to optimally remove moderate to high resistivity ash. The DC power supply is pulse width modulated to maximize the product of the peak electric field and the average electric field. The method used to optimize operation includes selecting initial on and off times for the power supply, operating the power supply using the initial off and on times, and progressively decreasing the off time. A determination is made whether the off time may be further decreased. Ultimately, the on and off time intervals that produce the highest peak and average voltage are determined, and the system is operated using these parameters. A procedure may be periodically repeated to monitor the process and detect if there has been a change in the system that would require new time intervals.

Abstract: A gas separation apparatus using electrostatic precipitators and mechanical rappers is enhanced by the addition of an opposite polarity refreshing power supply and a switching arrangement. The switching components selectively disconnect the primary power supply and connect the refreshing power supply to the electrostatic precipitator, causing an electrical impulse in the precipitator sufficient to dislodge precipitate from the collector plates. An RC filter is further provided to control the impulse and reduce the burden that would otherwise be placed upon the refreshing power supply. The novel separation apparatus and technique offer particular synergy when applied to the effluent stream from a coal-fired electric power plant or other similar gas streams.

Abstract: An apparatus and method for controlling voltage applied to an electrostatic precipitator is disclosed. This apparatus includes a pulsating, direct current, voltage mechanism that is operable to receive power from a single phase, alternating current voltage source, and a spiral wound filter capacitor, wherein the pulsating, direct current, voltage mechanism is electrically connected in parallel to the spiral wound filter capacitor and the spiral wound filter capacitor is electrically connected in parallel to the electrostatic precipitator. Optionally, a resistor is present to lower the transient voltage rating of the spiral wound filter capacitor. A switching mechanism may be utilized to apply differing amounts of capacitance and inductance in order to apply a range of voltage waveforms to the electrostatic precipitator to potentially maximize particulate collection efficiency for the electrostatic precipitator.

Abstract: An apparatus and method for controlling voltage applied to an electrostatic precipitator is disclosed. This apparatus includes a pulsating, direct current, voltage mechanism that is operable to receive power from a single phase, alternating current voltage source, and a spiral wound filter capacitor, wherein the pulsating, direct current, voltage mechanism is electrically connected in parallel to the spiral wound filter capacitor and the spiral wound filter capacitor is electrically connected in parallel to the electrostatic precipitator. Optionally, a resistor is present to lower the transient voltage rating of the spiral wound filter capacitor. A switching mechanism may be utilized to apply differing amounts of capacitance and inductance in order to apply a range of voltage waveforms to the electrostatic precipitator to potentially maximize particulate collection efficiency for the electrostatic precipitator.

Abstract: An improved method and system is provided to control the rapping process used to clean the internal collection plates and discharge electrodes of electrostatic precipitators. The system obtains the performance characteristics of a first rapper and calculates a rapper lift value. The system then obtains performance characteristic data from two or more additional rappers and calculates rapper lift values for each of the rappers. Finally, the system compares the rapper lift value of each additional rapper and adjusts its performance characteristics so that it substantially approximates the performance characteristics of the first rapper.

Abstract: A method of operating an electrostatic precipitator (7) includes feeding the precipitator with electric power generated by a power supply (10) according to a regime adapted to impart between the precipitator electrodes a voltage having a DC component and an AC component. A control unit (8) measures the electrode voltage, establishes a voltage peak value and a voltage mean value, and computes the product of peak value by mean value to arrive at an index of expected performance (IEP). Operating set points are tuned so as to maximize this index of expected performance.

Abstract: The method of invention relates to a method and device for generating voltage peaks in an electrostatic precipitator via generation of current pulse, where each voltage peak is generated by a group of current pulses. A device according to the invention comprises a first and a second means for converting alternating current to direct current, and also so first means for converting direct current to alternating current, and the first means for converting direct current to alternating current comprises a resonance converter.

Abstract: An apparatus and method for generating slow rise-time, high voltage electrical pulses to a load, preferably using an existing transformer/rectifier set or power supply to charge an inversion or high voltage switching circuit to produce the pulsed voltage. An energy recovery circuit (100, 102) is used to return unused energy from the load (24) back to the means for producing pulsed voltage (110, 130). A load matching circuit (120) uses a blocking diode and a capacitor for charging the load. An additional blocking diode (32) inhibits load voltage discharge back through the slow pulse generating circuit. A transformer (20) can be used to step-up voltage from the inversion circuit, or high voltage switching circuit, to the load. One or more magnetic switch stages are used to transfer energy from the inversion circuit, or high voltage switching circuit, to the load matching circuit. A fire-on voltage controller (66) triggers the inversion or high voltage switching circuit.

Abstract: Apparatus for the purification of air, flue gases in which apparatus the air, flue gases or equivalent are directed into a duct, in which apparatus the air, flue gases are ionized, and in which apparatus charged impurity particles (7) present in the air, flue gases or equivalent are attracted by one or more collector surfaces (2) by virtue of a difference in the states of charge, causing the particles to settle on the surface. The air, flue gases are ionized by virtue of one or more ionizing electrodes (5) directed at a collector surface. The distance between the ionizing electrode or equivalent and the collector surface and the difference between the state of electric charge of the collector surface and the charged impurity particles are so adjusted that the impurity particles will move essentially directly towards the collector surface and settle on it.

Abstract: In a power supply for an electronic precipitator with a power electronics part, a transformer connected at the output side and a high-voltage rectifier, the transformer and the high-voltage rectifier as well as a device for measured value acquisition are situated in the immediate proximity of the electronic precipitator, and the power electronics part is situated at a location remote from the electronic precipitator and, for control, is coupled to the device for measured value acquisition via optical conductors.

Abstract: An electrical apparatus includes a reaction chamber. A stream of contaminated gasses flows through the chamber. An elongated coronating electrode is positioned in the reaction chamber for producing a corona discharge within the chamber. A multi-stage Fitch generator connected to the electrode produces a high level, rapidly pulsating voltage in the electrode. Controlled amounts of an inert gas or inert gas-air mixture are combined with the contaminated gases to provide a high concentration of inert gas in the reaction chamber. In the inert gas-enriched atmosphere, the pulsating corona discharge produces a high concentration of metastable intermediates that greatly increase the rate of chemical conversion of the contaminants. Switching circuitry allows the pulsating voltage output of the Fitch generator to be superimposed on a constant direct current voltage in the electrode, setting up an electrostatic field in the reaction chamber for removing conversion byproducts from the gas stream.

Abstract: An apparatus for charging an electrostatic precipitator, powered by a power supply and having a plurality of corona electrodes and a plurality of collector electrodes, such that a precipitator capacitance may be formed therebetween, includes a storage capacitor across the power supply, having a storage capacitance. A voltage switch is capable of selectively electrically coupling the electrostatic precipitator to the storage capacitor. The storage capacitance is sufficient to charge the electrostatic precipitator to a preselected operative voltage within a rise time greater than a first preselected value and less than a second preselected value.

Abstract: A method for charging an electrostatic precipitator, powered by a power supply and having a plurality of corona electrodes and a plurality of collector electrodes, such that a precipitator capacitance may be formed therebetween, includes a storage capacitor across the power supply, having a storage capacitance. A voltage switch is capable of selectively electrically coupling the electrostatic precipitator to the storage capacitor. The storage capacitance is sufficient to charge the electrostatic precipitator to a preselected operative voltage within a rise time greater than a first preselected value and less than a second preselected value.

Abstract: An electrical filter apparatus for an electrostatic precipitator, wherein the filter apparatus is a T-type or pi-type filter electrically connected to a high voltage output of an electrostatic precipitator power supply and an electrostatic precipitator electrode. The T-type filter comprises a first inductor electrically connected to the high voltage output and a capacitor that is also electrically connected to ground. A second inductor is connected to the first inductor and the electrostatic precipitator electrode. In another embodiment, a two-stage inductor assembly is provided having a third inductor member defined by a plurality of turns of a continuous length of wire, and a fourth inductor member defined by a plurality of ferrite beads in end-to-end relationship.

Abstract: A miniature air purifier produces a corona discharge surrounding a needle-like emitter point connected to a negative DC power supply. The power supply operates from a nine volt battery and contains a step-up voltage inverter having a single transformer outputting high voltage spikes with a voltage multiplier operating on the output of the inverter. The production of high voltage spikes of about 200 Hz rather than a sinusoidally varying voltage significantly reduces current consumption. The needle-like emitter point is located about 1/4-inch from an 80% open mesh metallic grid held at ground potential. Corona discharge at the emitter point ionizes the air and creates ozone, and nitric oxide both of which combine with direct electron impact decomposition to detoxify and destroy a wide variety of airborne pollutants including pathogens, chemicals and allergens.

Abstract: A pulse charging apparatus includes a DC high-voltage generator, a capacitor that is charged by a DC high voltage output from the DC high-voltage generator, a switching unit for switching charges stored on the capacitor to provide a pulse-like high voltage to a load, and a control unit for controlling the operation of the switching unit. The switching unit consists of a series combination of an electron tube and a stationary gap. The control unit controls the operation of the electron tube.

Abstract: An electrostatic precipitator circuit has an input terminal supplied DC voltage, an output terminal connected to a precipitating capacitor, a storage capacitor connected between ground potential and the input terminal, and a recovery capacitor whose one electrode is applied with ground potential. The circuit further includes a current path switching unit having a common terminal and first and second switch terminals to be connected to the common terminal, the common terminal being connected to a non-ground electrode of the storage capacitor.

Abstract: A method and apparatus for varying an electrically variable current limiting reactor (VICLR) ( 16) are provided in cooperation with an electrostatic precipitator automatic voltage control system. The inductance of VICLR (16) is varied by altering the DC current in control winding (66) of VICLR (16). A power source (10) connects serially to an inverse parallel SCR1 and SCR2, to VICLR (16), and to a TR set comprising a transformer (18) and rectifier (20) which supply power to precipitator (22). System electrical characteristics on both sides of the TR set are monitored. Computer (40) uses these monitored values to continuously calculate form factor and fractional conduction values. Step-down transformer (60) is connected to solid state relay (62) which is in turn connected to full wave bridge rectifier (64). Rectifier (64) is connected to control winding (66) of VICLR (16). Solid state relay (62) is also connected to computer (40).

Abstract: A miniature air purifier produces a corona discharge surrounding a needle-like emitter point connected to a novel negative 8,000-volt DC power supply. The power supply operates from a nine volt battery and contains a step-up voltage inverter having a single transformer outputting high voltage spikes with a voltage multiplier operating on the output of the inverter. The production of high voltage spikes of about 200 Hz rather than a sinusoidally varying voltage significantly reduces current consumption. The needle-like emitter point is located about 1/4-inch from an 80% open mesh metallic grid held at ground potential. Corona discharge at the emitter point ionizes the air and creates ozone, and nitric oxide both of which combine with direct electron impact decomposition to detoxify and destroy a wide variety of airborne pollutants including pathogens, chemicals and allergens.

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: There is provided a capacitor having an end connected to the ground and the other end connected through a secondary winding of a pulse transformer to the discharge electrode. The ground side terminal of the capacitor is connected through a smoothing circuit to a positive voltage side output terminal of a base power supply circuit and a negative voltage side terminal of the base power supply circuit is connected to the discharge electrode side terminal of the capacitor. An output terminal of a pulse power supply circuit is connected to a primary winding of the pulse transformer. The base voltage and the pulse voltage can be controlled independently, and it becomes possible to apply a steep pulse with large output power to the discharge electrode.

Abstract: An improved electrostatic precipitator system is provided for use in high-grease atmospheres in which the grease is electrically conductive. The precipitator includes high-voltage insulators that are both located in areas unlikely to accumulate electrically-conductive grease and that, in themselves, can operate in a high-voltage system without tracking, even when a certain amount of conductive grease has accumulated on the insulators' surfaces. In a multi-cell precipitator system, a high-voltage insulator is provided as part of a cell-to-cell assembly that receives high-voltage electricity on one side of its insulator, and conducts that electricity to its opposite side, and is placed in a specially-shaped cut-out in the bulkhead between the cell chambers, in which the cut-out is shaped so as to minimize the amount of grease that may accumulate upon the cell-to-cell assembly's insulators.

Abstract: Air purification system where air is subjected to complex electrical field resulting from a DC voltage and AC frequency in kilovolt and kilohertz range respectively, applied to screen assembly in air path. DC amplitude and AC frequency self regulate to selected parameters. Parameters are selectable independently of one another.

Abstract: Electrical apparatus for removing ecologically noxious substances from gases which includes an electrical precipitator having a reaction chamber through which a stream of the gases to be cleaned passes, and which includes an elongated electrode extending into said reaction chamber for producing a corona discharge within the chamber. The apparatus of the invention includes a multi-stage Fitch generator connected to the electrode which produces a high level pulsating voltage superimposed on a constant direct current voltage. The pulsating voltage causes the electrode to produce the corona effect in the chamber, and the constant direct current voltage sets up an electrostatic field which removes unwanted products of the corona discharge from the gas stream passing through the chamber. The Fitch generator is adapted to provide pulsating voltages of sufficient amplitude and steepness to produce a high density, high energy corona discharge within the chamber.