Abstract: In an electrostatic precipitator for cleansing flue gases from industrial plants, comprising one or more precipitator sections powered from a separate continuous or intermittent DC-voltage electric supplies, a method and apparatus for detecting back corona, i.e. discharges in the dust layer precipitated on the collecting electrodes of an emission electrode system during the cleansing process, by making periodic upward adjustment of the precipitator current for each DC-voltage supply until spark-over occurs, and where after spark-over or a blocking of the precipitator current for a predetermined period of time if no spark-over occurs, the minimum value of the precipitator voltage is compared wtih the minimum value before the spark-over or before the blocking period, the latter minimum value being corrected by means of a predetermined sensitivity factor.

Abstract: A scrubber comprises a casing (1) with an inlet (2) and an outlet (3) for flue gases, and with an outlet (4) for water and substances separated from the flue gases, and water injection nozzles. The casing (1) is divided, by means of a partition having a throughflow opening for flue gases, into an evaporation zone (11) in which injected water is caused to cool the flue gases by heat absorption and evaporation, simultaneously as the water adsorbs any substances carried along by the flue gases, and a condensation zone (12) in which flue gases and steam from said first zone are condensed. The flue gas outlet from the condensation zone is provided with a drop separator (8), and the partition (151) separating the two zones is arranged as a collector of water which has not evaporated in said evaporation zone and which by means of a pump (16) and further nozzles (17), is reinjected into said evaporation zone (11).

Abstract: Apparatus for treating particles while the particles are suspending in a circulating stream of air or other fluid. The apparatus causes particles to rotate around a vertical axis in confined circular paths of travel generally lying in a horizontal plane.

Abstract: A plate-like filter element includes a plate-like body made of a gas-permeable porous material having a pair of opposing end faces, a plurality of through holes formed in the plate-like body from one of the end faces to the other, wherein the plurality of through holes have inner wall surfaces which extend out toward both side surfaces of the plate-like body, the side surfaces being closer to the through holes. A filter unit is formed by a plurality of the plate-like filter elements stacked up in parallel to each other so that the end faces of the stacked filter elements are aligned, and passages separated from the through holes by the porous walls of plate-like bodies are formed between the adjacent filter elements. A filter device includes a metallic casing with an inlet for a dust-containing gas, an outlet for clean gas and an outlet for dust, which firmly support the filter unit therein.

Abstract: An arterial air eliminator includes an upper housing (10) and a lower housing (12). A first internal chamber (16) is formed adjacent the interior sides of the housing with an inlet tube (18) disposed in the upper end thereof. A purge outlet (20) is provided at the upper end of the air eliminator with a filter element (32) defining an interior chamber (24). Fluid flows into the inlet (18) and then through the filter (32) to an interior chamber (34) and out an outlet tube (36) on the lower end of the housing. The filter element (32) has a bubble point that is graduated from the top to the bottom such that the bubble point on the upper end is large relative to the bubble point on the lower end thereof. The microbubbles which exist in the fluid entering the inlet tube (18) are not passed through the upper end of the filter (32) and are purged to the outlet (20).

Abstract: In a method and an arrangement for breaking a foam, especially in installation for wet chemical treatment of printed circuit boards with stations in which a treatment liquid is sprayed in a working plane onto a substrate to be treated and from where it is discharged into a supply tank located underneath, a produced foam is aspirated from a supply tank, and the aspirated foam is passed through at least one chamber which contains filling bodies on which foam bubbles burst on contact therewith.

Abstract: An air cleaner has a filter, an annular filter holder formed on the peripheral edge of the filter, a flange portion of U-like cross-section to which the outer circumference of the filter holder is embedded, and a case provided with an air inlet port and an air outlet port. This case is molded in blow molding using a filter member constituted integrally by the filter and the filter holder as an insert. In this air cleaner, the constitution parts, become as little as possible.

Abstract: A down draft air re-circulating filtration system for auto body shops and the like companies a filtration unit intaking air from the floor and having a series of three filters removing particles greater than about 1 micron and a fabric ducting distributing the filtered air at a multiplicity of points just under the ceiling to create a "blanket" of filtered air under positive pressure that settles towards the floor and the filtration unit intake.

Abstract: Disclosed are passive electrostatic particle collectors (10 & 12) for use in vacuum chambers (24 & 32) especially for a particle beam machine system (30 & 36) to collect particulates, such as dust and debris, generated by moving parts (16) within such chambers (24 & 32). These electrostatic particle collectors (10 & 12) comprise Tourmaline crystals (12) mounted on a bracket plate (10) and strategically located where dust and debris are generated. Also disclosed is a method of removing particulate material in vacuum chambers generated by moving parts by passive electrostatic particle collectors.

Abstract: A method for removing precipitate from a collecting surface of an electrostatic precipitator by rapping a point on the surface. Mechanical energy is applied a plurality of times with a rapper wherein the level of mechanical energy increases from one application of energy to another. Thus precipitate is removed from regions of the collecting surface progressively more distant from the energy application point. The time period between applications is selected to cause removal of precipitate from a region of the surface to be coincident with falling precipitate from regions above. The level of mechanical energy is controlled by applying to the rapper a sequence of full half-cycles of electrical energy followed by a single phase conduction cycle. The applied current is sensed and the duration of current application is adjusted to provide a predetermined energy level to the rapper. The polarity of the current is reversed to prevent magnetization of the rapper.

Abstract: A process for causing gaseous trace element particles to pass from a flowing hot gas into a fine particulate material by means of water. A mixture of the hot gas and water drops is caused to flow substantially upwards at such a velocity that the water drops remain in the gas flow and for a period long enough for most of the mass of the water drops to evaporate in order to cool the gas and to increase its relative humidity. After the gases have reached their wet temperature, they are brought into a turbulent state in order to cause the dust particles and the water drops which have decreased through evaporation to impinge against each other in order to produce in the aqueous film which covers the dust particles an exothermal ion reaction between the gaseous water-soluble trace element particles and the fine particles. Thereafter, the mixture is caused to flow further in order to evaporate the remaining water by means of the heat of reaction so that a dry end product is obtained.

Abstract: This invention is a method for removing dissolved gas from a liquid. The liquid is directed into a container, and is atomized upon entry. At the same time, a relatively inert gas is also directed into the container, so as to contact the atomized droplets. The addition of the inert gas to the container alters the relative partial pressure of the dissolved gas, especially when gas of the same type has been previously removed from the interior of the container. The result is that both the dissolved gas and the inert gas tend to vent from the container. The droplets of atomized liquid settle towards the bottom of the container, to form a pool of liquid. This liquid can then be withdrawn from the container. The liquid leaving the container can also be analyzed for its dissolved gas content. If the output liquid is not sufficiently degassed, the rate of flow of inert gas into the container is increased. Increasing the flow of inert gas into the container reduces the dissolved gas content of the output liquid.

Abstract: A cyclonic separator for particles suspended in the flow of an air stream. The separator comprises first and second spiral baffles adapted for mating engagement one within the other for imparting cyclonic flow to the air stream for collecting the particles from cyclonic motion thereof. The baffles are oriented with the first baffle rotated relative to the second baffle to therein form a flow path therebetween. The flow path between the baffles has in it a reversing, oppositely directed concentric spiral passage which carries the particles in a first spiral direction and then in a second opposite spiral direction. Each inner terminal end of the first baffle, or each outer terminal end of the second baffle, or both, may include an arcuate region of sharply increasing curvature adapted for collecting strayed paint particles and solvent droplets.

Abstract: A load chamber of a load lock is provided with a vertical air curtain which isolates the load chamber from the general clean room environment. Horizontal air flows generated in the load chamber bathe wafers held horizontally in the chamber with filtered air. These horizontal air flows are captured by the air curtain and recirculated to filters which provide horizontal and vertical air flows in the load chamber. If desired, the vertical and horizontal flows may be driven by the air supply mechanism of the clean room itself.

Abstract: A spray booth for coating photographs with lacquer has a hooded work area exhausted through a filter to capture overspray and solvents. A perforated work holding platen is provided together with a pre-heating and drying air supply to minimize blushing of the lacquer coat. The spray gun is a low pressure heated system that is track-mounted for uniform coating by unskilled operators.

Abstract: An electrostatic powder coating booth has double walls which can be evacuated to hold replaceable cover foils thereagainst so that, for a color change, a contaminated stretch of foil can be replaced by a fresh stretch of foil.

Abstract: A method and apparatus for automatically propelling a charge of backwash fluid by a compressed gas such as steam to backwash a filter in a filter pair. The method and apparatus provides for backwashing a filter with at least three backwash phases, a first mainly comprising a charge of backwash fluid passing through the filter with significant speed, a second relating to use of flashing steam for secondary cleaning and scrubbing of the filter elements, and a third relating to use of low pressure steam for autoclaving and sterilizing the filter.

Abstract: Apparatus adapted for use in a water clarification system which removes particles of greater than a predetermined size from the clarified water includes a screen or a pair of concentric screens positioned in a clarified water storage area between an inlet and a clarified water outlet. One or more spray heads for direct a shower of high pressure filtered clarified water at the outlet side of the screen or screens to loosen or remove particles therefrom. In addition, a rotating brush can act on the inlet side of the screen. Particles removed by the cleaning elements are recirculated through the system. Water levels are maintained by overflow control or by monitoring the water level and utilizing the output from the monitor or monitors to selectively control valves in the inlet or outlets from the system.

Abstract: A centrifugal filter for separating aerosol particles from a gas stream including a rotatable hollow hub and at least one pair of disks fixedly mounted in spaced apart relationship on the hub within a stationary housing mounted on the hub. The hub is perforated in the region between the two disks and is coupled to a vacuum pump so that the interior of the hub is at a lower pressure relative to the space between the disks. The hub is rotated, causing rotation of the disks. Aerosol particles in a flow gas are introduced between the disks and the housing at the periphery of the rotating disks. The pressure differential produced at the hub perforations draws the aerosol laden gas toward the hub. As the aerosol laden gas enters between the rotating disks and the housing, it experiences an acceleration to nearly the angular velocity of the disks, which results in a centrifugal force being applied to the aerosol particles in a direction opposite to the drag force exerted by the vacuum pump.

Abstract: Apparatus for treating particles while the particles are suspending in a circulating stream of air or other fluid. The apparatus causes particles to rotate around a vertical axis in confined circular paths of travel generally lying in a horizontal plane.