Abstract: An electrostatic precipitator and a method of removal of particulates from gaseous flows. A plurality of screens, secured in sets within a central chamber in a housing, include at least one set of electrically chargeable first screens and at least one set of electrically grounded second screens. For each set of chargeable screens, all the screens of the set are provided with an identical electrical charge, either positive or negative, and the set is provided with a plurality of spikes directed at the oncoming gaseous flow. At least one screen cleaning unit selectively acts on the screens of each set. The precipitator can include a plurality of central chambers in a single housing or separate housings, and the chambers can be selectively activated or deactivated. The precipitator provides improved particulate removal from gaseous flows, including hot flows having temperatures up to at least 1200° C.

Abstract: A computer system includes a computer chassis housing a processor and having a dust filter disposed in an airflow pathway through the computer chassis. A plurality of electrodes is disposed across an area of the dust filter, and a voltage source is provided having a negative terminal and a positive terminal. A controller selectively couples a first subset of electrodes to the negative terminal and selectively couples a second subset of electrodes to the positive terminal, wherein a voltage differential between the first subset of electrodes and the second subset of electrodes is sufficient to cause electrostatic movement of dust from an area of the dust filter near the first subset of electrodes to an area of the dust filter near the second subset of electrodes.

Abstract: A method for removing particulate matter from a particulate-bearing gas stream includes flowing a particulate-bearing gas stream at a first volumetric flow rate to a plurality of ESP units; producing electrically charged particulate matter; collecting electrically charged particulate matter on collection electrode plates; reducing the flow through at least one of the ESP units; sequentially increasing the flow through one or more remaining ESP units in an amount so as to maintain the sum of flow through all of the ESP units at the first volumetric flow rate; subjecting the collection electrode plates in the at least one ESP unit with reduced flow to forces which dislodge the particulate matter from the collection electrode plates; collecting the dislodged particulate matter in a particulate collection receptacle; and withdrawing a gas stream of reduced particulate matter contamination.

Abstract: A PM sensor is provided having high responsiveness and capable of long term detection. A PM sensor includes a sensor element that has particulate collection electrodes to which a particulate collection voltage for causing particulate matter contained in exhaust to adhere to a sensor element is applied, and measurement electrodes to which a measurement voltage for measuring an electrical characteristic of the sensor element is applied, in which, after a particulate collection voltage is applied to the particulate collection electrodes application of the particulate collection voltage is stopped in response to a predetermined condition being satisfied, the measurement voltage is applied to the measurement electrodes and the electrical characteristic of the sensor element is measured.

Abstract: A device and method for controlling the rapping of at least one collecting electrode plate (30) of an electrostatic precipitator (1) is provided. The device controls such rapping by applying, by means of a power source (32), a voltage between at least one collecting electrode plate (30) and at least one discharge electrode (28). The sparking rate between the at least one collecting electrode plate (30) and at least one discharge electrode (28) is then measured, with the rapping of the at least one collecting electrode plate (30) controlled using the measured present sparking rate.

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 method of operating a filtration system that filters flue gas, which includes particulate matter and a gaseous pollutant. The filtration system may include a fabric filter, which is cleaned with periodic pulse cleanings, a discharge electrode upstream of the fabric filter, which imparts an electric charge to at least some of the particulate matter before the particulate matter collects on the fabric filter, a sorbent, which is injected into the flue gas upstream of the fabric filter and absorbs at least some of the gaseous pollutant, and a fan, which draws the flue gas through the fabric filter. The filtration system may have a pulse cleaning interval setting that may be manipulated by an operator of the filtration system. The pulse cleaning interval setting may be the time between the pulse cleanings.

Abstract: This invention relates to an electrostatic precipitator suitable for removing industrial dust particles. This electrostatic precipitator with high efficiency includes a casing, in which the corona discharge electrode lines and the dust-collecting electrode plates, which form a plurality of sedimentation passages, are arranged in parallel and alternately. The vibration apparatuses for cleaning dust are placed respectively on the corona discharge electrode lines and the dust-collecting electrode plates. The wind shields are arranged alternately at both ends of each two adjacent sedimentation passages to form a plurality of air intake sedimentation passages and air exhaust sedimentation passages which are arranged alternately. The passages, where the wind shields are located on the side of air outlet are the air intake sedimentation passages and the air exhaust sedimentation passages with the wind shields located on the side of air inlet.

Abstract: A tower ionizer air cleaner is provided. The tower ionizer air cleaner includes a tower chassis, with a base of the tower chassis including a small footprint, one or more airflow inlet openings in the tower chassis, one or more airflow outlet openings in the tower chassis and substantially opposite to the one or more airflow inlet openings, and an ionizer element positioned within the tower chassis. The tower ionizer air cleaner further includes one or more fan units substantially vertically located within the tower ionizer air cleaner and affixed to the tower chassis. The one or more fan units are configured to provide an airflow between the one or more airflow inlet openings and the one or more airflow outlet openings and through the ionizer element.

Abstract: An air cleaner is provided that includes one or more ionizing panels having at least one ionizing wire in connection with a voltage source. One or more collector cells separate from the one or more ionizing wire panels are releasably received within the air cleaner housing to establish an electrical connection between the collector cell and the voltage source for applying a voltage potential between the collector cell and the ionizing wire. The collector cell may be removed from the air cleaner to permit cleaning of the collector cell separate from the ionizing panels. The air cleaner monitors at least one variable indicative of the operation of the air cleaner. Upon determining that the variable has reached a predetermined level indicative of a significant amount of dust accumulation, a controller activates a light source to illuminate indicia on a display screen which indicates a need for servicing the air cleaner.

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: A method for operating a filter assembly having a filter medium includes applying a constant or nearly constant static DC potential to dust entering the filter assembly and the filter medium, passing dust-laden gas through the filter medium in a first direction through the filter assembly while the filter medium is statically charged with the DC potential, measuring pressure drop through the filter assembly, and, in response to the pressure drop meeting a preset limit, reversing the polarity of the DC potential to thereby allow dust particles on the filter medium to drop off the filter medium.

Abstract: A spot ventilator and method for spot ventilating a localized environment of a building is provided. The spot ventilator includes a passage and at least one corona discharge apparatus. The passage extending between an inlet positioned in the localized environment and an outlet. The at least one corona discharge apparatus positioned in relation to the passage such that a fluid from the localized environment is drawn into the passage through the inlet and is expelled through the outlet. The method of ventilating a localized environment of a building includes the steps of sensing a first change in the localized environment, energizing a corona discharge apparatus to produce an electric wind, drawing air from the localized environment into a passage via the electric wind and expelling the air from the passage through the outlet.

Abstract: The present invention is embodied in a system for collecting biological samples from air including a collection assembly to store at least one biological sample and a separator to remove selected particles from the air prior to entry into the collection assembly. In one embodiment, the selected particles are magnetic and the separator includes at least one magnet to attract the particles from the air.

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 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 vapor filtration device including a first electrode, a second electrode, and a filter between the first and second electrodes is disclosed. The filter is formed of dielectric material and the device is operated by applying a first electric potential between the electrodes to polarize the dielectric material such that upon passing a vapor stream through the filter, particles from the vapor stream are deposited onto the filter. After depositing the particles a second higher voltage is applied between the electrodes to form a nonthermal plasma around the filter to vaporize the collected particles thereby cleaning the filter. The filter can be a packed bed or serpentine filter mat, and an optional upstream corona wire can be utilized to charge airborne particles prior to their deposition on the filter.

Abstract: An economical air purification system and process that greatly reduces concentrations of dust and noxious gases to provide for a cleaner and healthier enviroment for people, plants, poultry and other animals. Desirably, the special air purification system and process has a set of modules arranged for emitting overlapping flow patterns of ions. The modules can include parallel arrays of ionizers which are preferably arranged in a matrix or grid pattern. For even better results, the ionizers can comprise self-cleaning ionizers. One or more fans can be spaced from the modules to circulate the ions and air as well as draw influent air through the intake ports and exhaust purified air through the outlet ports. Heaters can also be provided to heat the circulating air.

Abstract: Method for substantially improving the shadow detail and color spectrum range of multicolored lithographic reproductions including the preparation of and printing with standard halftone printing plates and overprinting with a secondary printing plate made from a color separation used in making the halftone printing plates; the secondary printing plate being made from a secondary image exposed through a random pattern screen.

Abstract: An improved two printing step process for reproducing visual subject matter including the making of a secondary printing plate with a positive image random pattern screen and printing a substrate sequentially and in registry with the secondary printing plate and a master printing plate made with a conventional half tone screen. The random pattern screen is a positive image phototransparency having a large plurality of irregularly shaped highlight areas and contrasting shadow areas per square inch, an optical density from about 0.17 to about 1.6, a contrast factor from about 0.75 to about 1.5 and a transparency factor from about 0.25 to about 0.60. The random pattern screen is made from a transparent plate having light disruptive projections on its surface. A negative and a positive phototransparency of the transparent plate are made while controlling exposure and developing conditions to produce a positive image screen having the desired characteristics.

Abstract: A photosensitive material such as photographic film is exposed with a color image through a color separation filter. An electroluminescent plate is placed over the film and exposed with the color image first through the color separation filter with the plate charged to one electrical polarity and again through a color and contrast compensating filter with the plate charged to the opposite polarity. A high electrical potential is applied to the electroluminescent plate causing the plate to radiate a luminescent image onto the film as a color and contrast compensation exposure.

Abstract: Methylenedisalicylic acid is added to ink containing a pigment derived from fluorescein to overcome tinting and scumming when the ink is used in offset printing.

Abstract: A repellent composition containing an oil of low volatility having a surface energy less than 27 dynes/cm. and a solid fluorinated polymer such as a polymer of a fluoroalkyl acrylate. In accord with certain embodiments of the invention, a resinous binder and/or a particulate fluorocarbon powder may be added to the repellent composition. The repellent composition may be used to prepare an ink repellent surface for a "waterless" lithoplate or as a coating on the surface of an electrographic element from which a liquid developed electrographic image is transferred.