Abstract: A method of reducing the pressure drop in a downflow/upflow wet flue gas desulfurization (WFGD) system and of improving overall sulfur dioxide collection efficiency by converting the downflow/upflow WFGD system to an upflow single-loop WFGD system. The method includes the replacing of the downflow quencher and related duct work with a bypass for connecting the incoming flue gas duct with the upflow absorber, and the adding of a quenching zone in the absorber comprised of spray headers.

Abstract: A method for removing impurity substances in air flowing in a flow passage includes filtering the air in a first filter for removing solid substances; cooling the air in a first cooler to not higher than its dew-point temperature; capturing gaseous substances in the air in a wet-type impurity removing apparatus; cooling the air in a second cooler; and filtering in a second filter. The wet-type impurity removing apparatus includes a first liquid atomizer having two pluralities of nozzle ports for spraying, arranged mutually spaced apart and facing each other in the direction of the air flow passage; first and second condensing and capturing assemblies located across the first atomizer and spaced apart from each other, with the first assembly being upstream and the second assembly being downstream from the first atomizer; a second atomizer for capturing any remaining gaseous substances in the air; and a third condensing and capturing assembly.

Abstract: According to the invention, the vapor is taken from the condensation chamber of the dehydrator and, prior to being compressed and at a temperature substantially equal to 100° C., it is caused to pass in succession through a series of purifiers, and in each of the purifiers it is forced through rain containing a purifying solution, at least one of the rain solutions being water, another containing an acid, and another containing a base. The invention is applicable to treating the vapor that results from dehydrating a variety of kinds of matter, such as farmyard manure, in particular.

Abstract: In a wet-process gas treatment method of treating an acid gas by means of at least two treating columns connected in series, ratio of concentration of acid gas at an outlet to concentration of acid gas at an inlet, of a first treating column is set higher than ratio of concentration of acid gas at an outlet to concentration of acid gas at an inlet, of at least one of other treating columns, thereby preventing deposits from forming in the interior of connecting pipes between the columns and in the interiors of the treating columns, to prevent the connecting pipes from their blockage.

Abstract: Effluent gas cleaning process and apparatus for effectively removing particulates in the 0.01 micron to 0.1 micron diameter range, and for removing water-soluble gaseous contaminants, by first bringing the effluent to a relatively high temperature and humidity in a first stage, and then exposing the effluent to copious quantities of small cool water droplets in a second stage, for particular combinations of: the first stage relative humidity; the first-to-second stage droplet temperature difference; the stage two water droplet mass flow rate vs. effluent flow rate; the second stage droplet size; the travel time of the effluent during exposure to the cool droplets; and the electrical charge state of the second stage water droplets and opposite charge state of the particulates. The combinations enhance effluent cleaning through the combined operation of up to four distinct physical processes which can be made to occur during the second stage.

Abstract: The object of the invention is to provide a method of treating wash water resulting from the scrubbing of process gases in smelting plants, according to which method the wash water is brought into intimate contact with the process gas and is circulated when the solids have been deposited. The method according to the invention draws off a partial flow from the wash water, mixes it with fresh water and uses it for rewashing the process gas. According to the invention, the wash water necessary for the scrubbers is drawn from a wash water container. In the sedimentation tank the insoluble portions are removed from the substance-charged wash water which is then introduced into the wash water container. The wash water required for the rewashing stage is removed from the wash water container and mixed with fresh water via the fresh water pipe.

Abstract: A pollution control apparatus and method to scrub sulfur dioxide uses a lime slurry consisting of small diameter hydrated lime particles injected into the cooling water of a gas cooling tower. The diameter of the lime slurry particles is selected to be less than about 25 microns so that the lime particles substantially dissolve during the evaporative lifetime of the spray droplets. A preferred embodiment of the pollution control apparatus uses an in-line wet grinder and classifier to produce slurry as required.

Abstract: A method of filtering an air or gas stream utilizes a liquid, such as water, to saturate the gas stream. A sufficient quantity of water is presented to the gas stream to saturate the gas stream and knock particulate matter out of the gas stream. The gas stream can be cooled prior to saturating it with liquid. It may be desirable to reduce the flow rate of the gas stream to ensure maximum filtration. After the particulate matter is knocked out of the gas stream, it can be removed and processed as desired.

Abstract: A treatment system for process exhaust streams containing NOx. The system includes a plurality of sequential scrubbing assemblies that collectively receive and contact a process exhaust stream containing NOx and a water stream to produce a product exhaust stream with a concentration of NOx that is below a determined threshold value. The removed NOx forms a portion of a system waste liquid stream that includes a majority of the NOx removed from the process exhaust stream.

Abstract: A method and apparatus for quenching and scrubbing a hot gas using a liquid in a single packed column while controlling mist formation. Hot gas is introduced at the bottom of the column and drawn upward countercurrent to the scrubbing liquid. The column has three stages, each packed and fed liquid from above. The first stage is a quench region wherein the gas flow rate, liquid flow rate and liquid temperature are controlled such that the quench rate does not exceed 5.4° C./ft2 of packing to prevent formation of an aerosol mist. The second and third stages for scrubbing employ packed regions separately supplied with increasingly cooler and purer liquid.

Abstract: The exhaust gas enters via an exhaust gas line into a washing apparatus. In the washing apparatus solid matter particles are predominantly separated. The pre-washed exhaust gas flows from the washing apparatus through a droplet removing conduit to a trickling filter device in order to be subjected to an activated sludge treatment for the separating of gaseous contaminants. In order to reduce the point of condensation and accordingly the absolute humidity of the exhaust gas for the activated sludge treatment either fresh air is added through a feed line to the pre-washed exhaust gas or the washing water which is led in a closed circuit through the washing water line of the washing apparatus is cooled in a heat exchanger in a cooling tower. A portion of the washing water of the washing apparatus is led through a first solid matter removing apparatus of which a portion of the filtrate is led to an activated sludge basin located under the trickling filter device.

Abstract: The invention relates to a method according to which the wet scrubbing of a gas flow is performed in at least three, advantageously six successive steps or phases, and the droplet separation of the scrubbed gases is carried out in a uniform cyclone-like droplet separator composed of several nested cylinders. The invention also relates to a method for momentarily bypassing, during a capacity rise, a scrubbing phase that causes pressure loss. As a result, there is obtained a clean and dropless gas that falls below the allowed dust content limits and can thus be either conducted to combustion or discharged in the open air. The invention also relates to an apparatus, a multiphase scrubber, for realizing the method. The invention is particularly suited to be used for scrubbing hot furnace gases from closed reduction furnaces, where said furnace gases contain easily inflammable components.

Abstract: A multiphase scrubber for the wet scrubbing of gases in several different phases comprises at least three separate basic scrubbing units so that the scrubbing of the gas is carried out in at least three, advantageously six, successive steps. The droplet separation of the scrubbed gases is carried out in a uniform cyclone-like droplet separator composed of several nested cylinders. A clean dropless gas contains a dust content below the acceptable limit. The scrubber is suited for scrubbing hot furnace gases from closed reduction furnaces.

Abstract: Sulfur oxides (SO.sub.x) are scrubbed from combustion effluents with economies in capital and operating costs by virtue of an arrangement of spray header piping and nozzles which permits ease of access for service with reduced spacing (e.g., 0.5 to 1.25 meters) between spray levels. At least two spray levels in a spray zone include a plurality of spray header pipes arranged parallel to the other spray header pipes within a spray level and vertically parallel to spray header pipes in at least one adjacent spray level. Each of the spray levels includes a plurality of spray nozzles extending from said spray headers. A majority of nozzles in a reference spray level are positioned such that lines drawn between them form a pattern of squares with the nozzles located at the corners of the squares. And, a majority of nozzles in an adjacent spray level are positioned over the centers of squares defined by four nozzles in the reference spray level.

Abstract: A scrubber for removing pollutants from a fluid and having an inlet for receiving the fluid and an outlet for emitting the fluid, the scrubber comprising a first scrubber coupled with the fluid intermediate the inlet and the outlet for removing a first measure of pollutants from the fluid, a second scrubber coupled with the first scrubber intermediate the inlet and the outlet, the second scrubber for removing a second measure of pollutants from the fluid, and a third scrubber coupled with the second scrubber intermediate the inlet and the outlet, the third scrubber for removing a third measure of pollutants from the fluid.

Abstract: An exhaust gas desulfurization system includes a spray pipe which is provided with a plurality of nozzles in the lengthwise direction and whose one end is closed and arranged horizontally in an absorption tower through which the exhaust gas passes vertically. Absorbent slurry is fed from the other end of the spray pipe and is injected upward from the nozzles, by which absorbent slurry is brought into contact with the exhaust gas to perform treatment in the absorption tower. The flow passage on the closed end side of the pipe is present in a shape such that the flow passage cross-sectional area decreases toward the closed end.

Abstract: An improvement in a center inlet type scrubber that retrofit the scrubber with a perforated tray made up of rectangular or partially rectangular sections supported on beam supports in the annulus of the scrubber. The supports can be modified to form turning vanes or additional turning vanes can be employed. One or more perforated trays may be installed in the annulus to help correct the problem.

Abstract: Process gases from microelectronic device fabrication processes are pumped through a filter unit including a plurality of absorbers for absorbing water entrained within the process gases. Residues deposited within the filtering unit are removed by spraying water on the absorbers. Water is prevented from escaping from the filtering unit into other portions of an exhaust gas system or into the environment by providing a curtain of pressurized, inert gas, within the filtering unit.

Abstract: Disclosed is a contaminated waste steam heat recovery apparatus 10 and method therefore which includes a primary condensing unit 38, a low pressure water washing unit 26, a liquid to liquid heat exchanger 36 and a vent fan 31. Waste gas is ducted from fryer 11 to a de-super-heating chamber 14 wherein superheated steam is converted to saturated steam by spraying water into the steam using spray nozzles 15. The gas is then introduced into a vertically disposed air to liquid heat exchanger 16 and is drafted downward therethrough. As heat is removed from the waste gas, water vapor in the steam condenses and in the process, collects some of the oil and hydrocarbons present. A plurality of condensate trays 19 are disposed below the bottom end of heat exchanger 16 in a cascading fashion to collect hold the condensate in the airflow path such that it will absorb some of the heat still present in the remaining waste gas.

Abstract: Gases containing solubles or suspended particles are mixed with a scrubbing liquid in a mixing apparatus having a chamber with a rotatable wheel mounted therein. The gas is mixed with a scrubbing liquid by the rotating wheel which has first and second scrubbing surfaces including vanes for creating turbulence and moving the gas through the chamber. The vanes on the first scrubbing surface increase in height from the axis of the wheel to its periphery to move gas radially outwardly. The vanes on the second scrubbing surface increase in height from the periphery to the axis of the wheel to move the gas radially inwardly.

Abstract: Exhaust components of a coating apparatus can be cleaned to remove coating material therein and/or can be periodically treated so as to prevent the buildup of coating material with exhaust components. Moreover, coating materials and cleaning liquids can be separated from the exhaust stream and collected to a drain. An exhaust manifold includes an integral rinsing mechanism and a fluid separator. Rinsing can be controlled automatically or manually.

Abstract: The present invention discloses an exhaust gas conduit for feeding exhaust gases to a scrubber wherein the conduit is equipped with a self-cleaning device mounted inside the conduit body adjacent to an outlet end of the conduit for dispensing a cleaning solvent onto the inside wall of the outlet end of the conduit such that solid depositions on the inside wall can be avoided. The present invention is also directed to a method for preventing solid depositions in an exhaust gas inlet port to a wet scrubber by utilizing a self-cleaning device mounted in a conduit adjacent to an outlet end of the exhaust conduit and by dispensing a cleaning solvent through the self-cleaning device and spraying the solvent onto an inside wall of the outlet end of the conduit to prevent the formation of solid depositions on the inside wall.

Abstract: The invention relates to a multi-washer, and to a method of cleaning synthesis gases obtained by the gasification of wastes of the most varied composition. Such multi-washers are used to remove lumpy and adhesive materials from the synthesis gas, such as carbon particles and sulphur. According to the present invention, a horizontal container (1) is sub-divided by partition bulkheads (5) into a plurality of successive wash chambers (2,3,4), which are each provided with a sumpless outflow to a respective pump system (6,7,8). Disposed in each of the wash chambers (2,3,4) is a least one substance exchanger (9) in an oblique position, which is sprayed from both sides with varying quantities of wash liquid. The sprayed wash liquid penetrates into the substance exchangers (9) and, due to the varying quantity, is removed in an directed fashion. As the wash liquid also sprays the wall of the container (1), total self-cleaning of the multi-washer is ensured.

Abstract: An object of this invention is to provide a gas-liquid contact apparatus for use in wet flue gas desulfurizers and the like which is equipped with lightweight and inexpensive header pipes having excellent wear resistance and corrosion resistance and hence exhibits high reliability and economical efficiency. To this end, there is provided a gas-liquid contact apparatus wherein one or more header pipes having attached thereto a plurality of spray nozzles for spouting a slurry upward are disposed in the main body of a tower through which a gas flows, characterized in that the header pipes are made of a fiber-reinforced resin composite material and the outer surface thereof or the outer and inner surfaces thereof are formed of a corrosion-resistant and wear-resistant layer of a resin containing ceramic particles.

Abstract: Scrubber sterilization method which initially sterilize a gas scrubber with an initial cleaning with hydrogen peroxide, provide an iodine level of approximately 5 to 10 mg/liter in water which is sprayed into the scrubber to contact the effluent gas stream and kill biological growth, provide injection of more concentrated iodine in water in the event the iodine level in the system falls below a predetermined level, and load the filtrate material in the gas scrubber with iodine to provide an unfavorable surface for adherence of biological growth as well as a secondary sterilization means in the event that the liquid stream with iodine is stopped due to equipment or power failure.

Abstract: Exhaust gas is brought into contact with a washing liquid chiefly consisting of water in at least two washing stages. In the last washing stage, fresh water and/or a washing liquid containing fresh water is sprayed into the exhaust gas. In the penultimate washing stage, the exhaust gas is brought in contact with a circulating aqueous salt solution, which contains substances supplied by the exhaust gas. In the penultimate washing stage, the exhaust gas is passed through a washing zone at temperatures in the range from 30.degree. to 150.degree. C., where the quantity of aqueous salt solution passed into the washing zone per Nm.sup.3 exhaust gas flowing through the washing zone is 0.1 to 10 liters. The exhaust gas coming from the penultimate washing zone has a temperature in the range from 30.degree. to 80.degree. C., is saturated with steam for 90 to 100%, and does not contain more than 50% by weight of the dust content of the exhaust gas before the same enters the penultimate washing stage.

Abstract: A method for converting a double-loop flue gas desulfurization system to a single-loop desulfurization system includes removing the deep packing from the scrubber housing and replacing the packing with a thin tray having a plurality of perforations. The return line which connects the bowl is removed from the feed tank; and a plurality of openings, apertures or perforations are provided in the shroud ring and the bowl of the housing in order to permit slurry to pass from upper spray headers to the bottom of the housing as well as permit flue gas flow upwardly through the housing to the flue gas outlet. The lower spray headers are removed from the housing and the feed line connected to the lower spray headers is reconnected to the feed tank for providing the single-loop. An oxidation air system is provided in the feed tank for creating an in-situ forced oxidation system.

Abstract: A method and apparatus for separating solid and/or liquid particles and/or polluting gas from a gas stream includes two component nozzles by which a washing liquid is finely distributed in a gaseous phase and introduced in the gas stream within a gas washer. The two-component nozzles are distributed over the whole cross section of the washer, preferably on a plane that extends perpendicularly to the gas flow direction.

Abstract: For their wet purification, gases flowing in a line are sprayed with scrubbing liquor, the resulting mixture of gas and liquid is passed through a cyclone separator. The gas is initially sprayed in a pre-scrubbing line and the gas which contains scrubbing liquor is subsequently conducted through a substantially horizontal accelerating line having at its entrance a cross-sectional area which is 1.5 to 8 times larger than the cross-sectional area at its exit. The exit of the accelerating line communicates with the cyclone separator. Purified gas is withdrawn from the cyclone separator.

Abstract: A venturi scrubbing system optimized for removing the most optically active sized particles from a gaseous effluent stream is disclosed. Before entering the venturi the effluent stream is subcooled to cause condensation of water vapor and other condensibles, thereby greatly reducing the volume of the effluent stream. In the venturi stage a scrubbing liquid is added in the form of droplets having a median diameter which is optimized to remove the optically active particles. Preferably, the median diameter of the scrubbing liquid droplets is between 10 and 200 microns. A two-fluid nozzle may be used to efficiently form the droplets. After passing through the scrubbing stage, which may also comprise one or more impingement plates, the cleansed effluent may be passed through an afterburner to remove combustible materials such as organic vapors.