202 results about "Wet scrubber" patented technology

Process for removing mercury from flue gases of high-temperature plants, in particular power stations and waste incineration plants in which a bromine compound is fed to the multistage furnace and/or the flue gas in a plant section downstream of the furnace, the temperature during contact of the bromine compound with the flue gas being at least 500° C., preferably at least 800° C. The combustion is carried out in the presence of a sulphur compound, in particular sulphur dioxide. Subsequently to the furnace, the flue gas is subjected to an optional multistage cleanup for removing mercury from the flue gas, which cleanup comprises a wet scrubber and/or a dry cleanup.

An effluent gas stream treatment system for treatment of gaseous effluents such as waste gases from semiconductor manufacturing operations. The effluent gas stream treatment system comprises an oxidation unit to which an oxygen-containing gas such as ozone may be added, with input of energy (e.g., thermal, radio frequency, electrical, microwave, etc.), to effect oxidation of oxidizable species in the effluent, such as halocompounds (e.g., chlorofluorocarbons, perfluorocarbons), CO, NF3, nitrogen oxides, and sulfur oxides). The effluent gas stream treatment system may include a wet scrubber associated with the oxygen-containing gas source, so that the gas stream is contacted with the oxygen-containing gas during the wet scrubbing operation, to enhance removal of oxidizable species in the gas stream during treatment.

A method for capturing and reducing the mercury content of an industrial flue gas such as that produced in the combustion of a fossil fuel or solid waste adds a chelating agent, such as ethylenediaminetetraacetic acid (EDTA) or other similar compounds like HEDTA, DTPA and/or NTA, to the flue gas being scrubbed in a wet scrubber used in the industrial process. The chelating agent prevents the reduction of oxidized mercury to elemental mercury, thereby increasing the mercury removal efficiency of the wet scrubber. Exemplary tests on inlet and outlet mercury concentration in an industrial flue gas were performed without and with EDTA addition. Without EDTA, mercury removal totaled 42%. With EDTA, mercury removal increased to 71%. The invention may be readily adapted to known wet scrubber systems and it specifically provides for the removal of unwanted mercury both by supplying S2- ions to convert Hg2+ ions into mercuric sulfide (HgS) and by supplying a chelating agent to sequester other ions, including but not limited to Fe2+ ions, which could otherwise induce the unwanted reduction of Hg2+ to the form, Hg0.

A wet scrubber having a series of chambers for capturing and cooling exhaust gases generated during static test firing of rocket motors. Exhaust gas enters an inlet to a first chamber and is cooled and slowed by a spray solution. HCL gas is condensed and absorbed by the spray solution and precipitates to a liquid slurry at the bottom of the device. The remaining exhaust products enter a demister chamber where nozzles continue to spray the gasses as they pass upward and through a mesh-style demister at the top of the vessel. The demister filters liquid and solid waste particles from the gas stream, and the clean, dry gases are accelerated through a centrifugal fan into the atmosphere. A deflector is positioned within the inlet to the first chamber for containing parts in the event of a motor mal-function.

A method and apparatus for reducing mercury in industrial gases such as the flue gas produced by the combustion of fossil fuels such as coal adds hydrogen sulfide to the flue gas in or just before a scrubber of the industrial process which contains the wet scrubber. The method and apparatus of the present invention is applicable to installations employing either wet or dry scrubber flue gas desulfurization systems. The present invention uses kraft green liquor as a source for hydrogen sulfide and/or the injection of mineral acids into the green liquor to release vaporous hydrogen sulfide in order to form mercury sulfide solids.

In a method for removing mercury from flue gas produced by combustion devices burning coal and other fuels that contain mercury and chlorine the combustion process is controlled to generate a flue gas comprising fly ash containing at least 0.25% unburned carbon, and preferably at least 5.0% unburned carbon. In addition the flue gas is rapidly cooled from a temperature within the range of 1450° F. to 900° F. to a temperature below 900° F. at a rate of at least 1000° F. per second. This step will enhance the concentrations of Cl-atoms and Cl₂, which accelerates the rates of mercury oxidation in both the gas phase and on particle surfaces. Finally, the flue gas is directed to the particle removal device for removal of the fly ash to which some of the mercury is bound, and also directed to a wet scrubber for retention of the oxidized mercury vapor in wastewater and solid effluents.

A platform mounted emissions control unit includes a first system to reduce Particulate Matter (PM), Sulfur Dioxide (SO₂), and Volatile Organic Compounds (VOCs), and a second system to reduce Oxides of Nitrogen (NO_x). The systems serially process exhaust from a mobile or stationary pollution source. In one embodiment, first system is an Ionizing Wet Scrubber (IWS) and the second system is a Selective Catalytic Reducer (SCR), wherein the IWS processes the exhaust first to improve efficiency and service life of the SCR. A generator produces power required by the IWS and SCR, and heat from exhaust of the generator may be used convert urea to ammonia for use by the SCR, and to heat the exhaust flow into the SCR. The SCR may further include a heat exchanger to capture heat in the flow out of the SCR and use the captured heat to heat the flow into the SCR.

An effluent gas stream treatment system for treatment of gaseous effluents such as waste gases from semiconductor manufacturing operations. The effluent gas stream treatment system comprises a pre-oxidation treatment unit, which may for example comprise a scrubber, an oxidation unit such an electrothermal oxidizer, and a post-oxidation treatment unit, such as a wet or dry scrubber. The effluent gas stream treatment system of the invention may utilize an integrated oxidizer, quench and wet scrubber assembly, for abatement of hazardous or otherwise undesired components from the effluent gas stream. Gas or liquid shrouding of gas streams in the treatment system may be provided by high efficiency inlet structures.

Methods for removing carbonyl sulfide (COS) from a synthesis gas stream are disclosed. The method entails raising the water level of a wet scrubber so that hydrolysis of the COS may occur in the scrubber itself instead of a COS reduction chamber and no additional catalysts other than those naturally occurring in the production of the synthesis gas need be introduced into the scrubber. The water is raised, in one example, to a level such that water within an inner tube of the wet scrubber flows over an upper end of the inner tube. Raising the water level in the scrubber ensures intimate and vigorous interaction between the water, the COS, and the naturally occurring catalyst, and promotes the hydrolysis of the COS. In one example, the naturally occurring catalyst (e.g., alumina oxide) is present in the coal ash produced when coal is the fuel gasified that creates the synthesis gas stream.

The invention discloses a garbage incineration fume ultralow emission system. A garbage incineration fume purifying treatment device comprises an SNCR (selective non-catalytic reduction) device, a semi-dry type reaction tower, a slaked lime spraying device, an activated carbon spraying device, a bag type deduster, a steam heater, an SCR (selective catalytic reduction) reaction tower, a fume/fume heat exchanger, a wet type scrubbing tower, an induced draft fan and a chimney. The low-temperature fume after washing is performed with heat exchange in the fume/fume heat exchanger, heated, and exhausted out of the chimney. The garbage incineration fume purifying treatment device has the advantage that the emission of the fume is superior to the European Union 2000 standard.

Systems and methods for removing toxic emissions from flue gas of coal fired combustions units can be achieved. Decreasing nitrogen oxide and sulfur emissions from a coal fired circulating fluidized bed reactor can include treating flue gas using a selective catalytic reduction system and a wet scrubber. Furthermore, reducing the nitrogen oxide emissions from a pulverized coal reactor can be accomplished with a selective non-catalytic reduction system. Additionally, the reduction of sulfur oxide emissions from a pulverized coal reactor can be enhanced using dry and/or wet scrubbers. Such systems and methods provide improved levels of toxic emissions over currently available technologies.

A substrate coating system is provided which includes a substrate coating chamber; a gas box connected to the coating chamber and adapted to provide reagent gases to the coating chamber; and a reagent reclaim system connected to the substrate coating chamber and the gas box, wherein the reagent reclaim system includes a wet scrubber connected to the coating chamber; a polisher connected to the wet scrubber; and a dryer connected to the polisher and the gas box.

The invention provides a purification system for flue gas generated in hazardous waste incineration. According to the system, three deacidification filtering systems of dry dust removal, wet dust removal and cloth bag dust removal are combined; the disadvantages of the three deacidification filtering systems during the respective independent using processes are overcome; the treatment capability of acid gas in the flue gas generated by hazardous waste incineration is improved. The system comprises a quenching device, wherein the quenching device is provided with a flue gas inlet and a flue gas outlet; the flue gas outlet of the quenching device is communicated with a flue gas purification device through a pipeline; an outlet of the flue gas purification device is communicated with a chimney. The system is characterized in that the flue gas purification device specifically comprises a dry reactor, a bag dust remover and a wet washing tower, wherein the flue gas outlet of the quenching device is connected with a flue gas inlet of the dry reactor; a flue gas outlet of the dry reactor is connected with a flue gas inlet of the bag dust remover; a flue gas outlet of the bag dust remover is connected with a flue gas inlet of the wet washing tower; a flue gas outlet of the wet washing tower is communicated with the chimney.

One aspect of the invention relates to a method for removing contaminants from a flue gas stream (22). The method includes: removing fly ash from a flue gas stream (22) utilizing a particle collector (24); contacting the flue gas stream with an alkaline reagent in a wet scrubber (26); discharging a purge liquid (30) from the wet scrubber (26); combining at least a portion of the purge liquid (30) with at least a portion of the fly ash (48) to form moistened fly ash (60); and injecting at least a portion of the moistened fly ash (60) into the flue gas stream (22) upstream of the particle collector (24), whereby the moistened fly ash (60) removes at least a portion of contaminants present in the flue gas stream (22).

Disclosed is a method for the removal of soluble particulate matter from a gas stream, such as urea dust from the off-gas of a finishing section of a urea production plant. The method comprises subjecting the off-gas to at least two quenching stages an aqueous quenching liquid. The quenching liquid used in a first, upstream quench stage, is allowed to have a higher concentration of dissolved particulate matter than the quenching liquid in the second, downstream quench stage. The quenched gas is led through a particle capture zone, typically comprising one or more of a wet scrubber, a Venturi scrubber, and a wet electrostatic precipitator.

The invention provides a fume purification system based on advanced oxygenation combining wet scrubbing. The system is a combustion and exhaust system formed by a boiler, an ozone generator, a stirrer, a swirl nozzle, a reactor, a gas-liquid absorption tower and a chimney, wherein fume containing sulfur oxide, nitric oxide and mercury generated by combustion of the boiler and O3 generated by the ozone generator enter the stirrer together, are mixed, flow through the swirl nozzle, and are sprayed into the reactor with an ultraviolet lamp tube; and hydroxyl radical (.OH) with strong oxidability generated under excitation of ultraviolet radiation, SO2 in the fume, indissoluble NO and HgO are oxidized into gaseous products with higher dissolubility and enter the gas-liquid absorption tower to be absorbed and removed by water; Hg<2+> generated in the gas-liquid absorption tower captures and retrieves mercuric sulfide by adding sulfidion S<2-> in equal molar ratio; and the residual sulfuric acid and nitric acid mixed solution is used as an industrial raw material for recycling, and the cleaned fume enters the chimney so as to be exhausted.