Abstract: The present invention provides a flue gas conditioning system and method for generating conditioning agent used in the removal of entrained particles in a flue gas flow with an electrostatic precipitator. The invention involves a catalytic converter that is operable between an operative position where the flue gas is exposed to the catalyst and converts SO.sub.2 contained in the flue gas to SO.sub.3 when conditioning agent is needed and an inoperative position where the flue gas is not exposed to the catalyst when conditioning agent is no longer needed. The catalytic converter and related assembly may take variable configurations to accommodate various flue gas ductworks and space limitations and may carry one or more SO.sub.2 /SO.sub.3 converters providing a plurality of open and generally parallel flow paths of the flue gas.
Type:
Grant
Filed:
May 13, 1994
Date of Patent:
August 20, 1996
Assignee:
Wilhelm Environmental Technologies, Inc.
Abstract: A method for the selective control of the sulfur trioxide concentration in flue gases, to enhance the ash removal efficiency of electrostatic precipitators, which includes: catalytically converting a portion of the sulfur dioxide contained within the flue gas to sulfur trioxide, by passing a portion of such flue gas through at least one catalyst containing converter module which is positioned within such a flue gas stream; and selectively varying the quantity of flue gas passing through such module by providing an aspirating force to cause flue gas to be drawn through such a converter module.
Type:
Grant
Filed:
September 12, 1995
Date of Patent:
July 30, 1996
Assignee:
Wahlco, Inc
Inventors:
Fellix E. Spokoyny, Vincent F. Middleton
Abstract: Method for treating gas or vapor includes an impeller arranged in a duct which draws dusty or fume-laden air through the duct. One or more nozzles are arranged to spray fine droplets of water onto the impeller. Downstream of the impeller, a set of angled collection plates collect the fine water droplets emitted by the nozzle, together with dust or fumes collected by the droplets. The nozzle is connected to a high voltage source, so that the droplets emitted by the nozzle are electrostatically charged. This causes them to attract dust particles and other contaminants. The collection plates are earth, so that the charged droplets are attracted to them, improving the effectiveness of the apparatus. A second, auxiliary spray of fine uncharged droplets is directed over an entrance opening of the duct to prevent ignition of explosive gas or particles outside the duct.
Abstract: A method for removing pollutants from a combustor flue gas. The method includes the steps of supplying sorbent to a baghouse having a filter bag therein until the filter bag is coated with a predetermined amount of sorbent and introducing the flue gas into the baghouse. Pollutants in the flue gas are sorbed by the sorbent on the filter bag. A system is provided for performing the method of the invention.
Abstract: The invention is a method for reduction of sulfur trioxide in flue gases which includes (a) combusting air and petroleum coke in a combustion zone to produce a particulates, sulfur trioxide, and sulfur dioxide-containing combustion product gas; (b) passing the combustion product gas from step (a) to a dry electrostatic precipitator for removal of particulates and recovering the combustion product gas substantially free of particulates, or alternatively rearranging the steps so so that step "b" follows steps "c" and "d"; (c) admixing particulates with the combustion product gas from step (b), to produce a first mixture; (d) passing the first mixture from step (c) to an air preheater for cooling the first mixture and heating the air for combustion with the petroleum coke, wherein the sulfur trioxide in the first mixture condenses on the particulates, to produce a second mixture containing combustion product gas containing sulfur trioxide condensed on particulates and sulfur dioxide; (e) passing the second mixtu
Abstract: For the separation of dioxins and furans from exhaust gases from combustion plants, particularly from refuse incinerating plants, a process is described in which the dust and the gaseous pollutants HF, HCl, SO.sub.2, and SO.sub.3 are first substantially entirely separated from the exhaust gases in known manner, the thus prepurified exhaust gas is then supplied to a wet-process electrostatic precipitator, and 10 to 500 mg activated carbon powder per sm.sup.3 are added to the prepurified exhaust gas immediately before it enters the wet-process electrostatic precipitator.
Abstract: A combustion exhaust gas which is to be dedusted and denitrated is mixed with NH.sub.3 and at temperatures in the range of about 250.degree. to 600.degree. C. is passed through a fluidized bed. The fluidized bed contains a denitrating catalyst, which contains FeSO.sub.4. The combustion exhaust gas serves as a fluidizing gas in the fluidized bed. Fresh denitrating catalyst is supplied to the fluidized beg and comprises at least 90% by weight FeSO.sub.4, which contains water of crystallization and has particle size in the range from 1 to 150 micrometers. The treated exhaust gas is dedusted in an electrostatic precipitator.
Abstract: Improved apparatus and methods for the treatment of boiler flue gas with sulfur trioxide conditioning agent include the beneficial use of catalytic converters that can be located immediately adjacent the injection site for their sulfur trioxide output, that can be individually sized and manufactured for variable required conditioning agent outputs, that can be individually controlled and can provide substantially improved conversion efficiency and that can provide an efficient, flexible, effective and relatively inexpensive multi-boiler flue conditioning system.
Type:
Grant
Filed:
March 22, 1993
Date of Patent:
September 27, 1994
Assignee:
Wilhelm Environmental Technologies, Inc.
Abstract: A hopper system and electrostatic gun for injecting electrostatically charged sorbent particles into a polluted gas stream for inclusion in an apparatus that utilizes electrostatically charged sorbent particles for removing particulate matter and gases from a polluted gas stream. The invention includes a hopper system with a bin that is selected to hold a required volume of dry sorbent material and is arranged to feed a metered quantity of sorbent materials, preferably by a screw feed, to receive an air flow from a regenerative blower the air flow mixes with sorbent materials in a throat of a venturi line and transports that flow into a barrel an electrostatic gun. The air entrained sorbent materials travel around and along a charging wand that is centered longitudinally in the barrel bore, and is electrically connected to received a controlled voltage from a high voltage power supply.
Abstract: Apparatus arranged in a closed system for removing particulate matter and gases from a polluted gas stream that includes a sorbent particulate charging and injection gun for electrostatically charging sorbent particles and injecting them into a polluted gas stream to charge and agglomerize pollution particulates therein, the stream flowing into a collection system housing that contains a series of moving and static bed filters and provides for operations at pressures less than atmospheric, and at temperatures up to two thousand (2000) degrees F. The filter beds are maintained across the housing and spaced apart from front to back therein, each filter containing a media material selected for removing the charged agglomerized pollution and sorbent reacted particulates and reacting with gases in the polluted gas stream, providing for removal thereof to clean that gas stream that is then vented to atmosphere.
Abstract: A hot-side electrostatic precipitator removes particulate matter from a NOX-containing flue gas stream passing therethrough, the exit flue gas stream having a temperature of no less than about 450F. The precipitator contains a plurality of collecting surfaces arranged in a series of fields. At least some of the collecting surfaces carry a catalyst which promotes a reaction between NOX in the flue gas passing therethrough and a nitrogeneous compound. Preferably, a nitrogeneous compound such as ammonia is electrically charged and injected into the flue gas stream prior to its passing over the collecting surfaces coated with catalyst. The hot-side electrostatic precipitator may have catalyst coated onto fixed surfaces near its exit end.
Abstract: SO.sub.3 flue gas-condition systems (10) provide a controlled flow of flue gas-conditioning agent such as SO.sub.3 into a boiler flue gas and its entrained particulate material ahead of an electrostatic precipitator (14). The systems (10) monitor the opacity of the stack effluent and precipitator power and operate to maintain a flow of SO.sub.3 -conditioning agent into the boiler flue gas to provide minimal opacity of the stack effluent. The systems operate at SO.sub.3 -conditioning agent flow rate corresponding to minimal opacity of the stack effluent and to eliminate corrections that may be due to transient operating conditions such as boiler upsets, precipitator rapping and the like. The systems include features providing improved conversion of SO.sub.2 into SO.sub.3, integrated assemblies to provide a flow of SO.sub.2 and sulfur dioxide conversion units adapted to convert SO.sub.2 into SO.sub.3 at a plurality of remote SO.sub.3 injection sites.
Type:
Grant
Filed:
September 14, 1992
Date of Patent:
November 16, 1993
Assignee:
Wilhelm Environmental Technologies, Inc.
Abstract: A method for conditioning flue gas to improve the removal of fly ash by an electrostatic precipitator employs a relatively high concentration (4-71/2%) of SO.sub.3 conditioning agent. The SO.sub.3 is formed by combusting sulfur and excess air in a sulfur burner to produce a mixture of air and SO.sub.2 and converting the SO.sub.2 to SO.sub.3 in a catalytic converter. The ratio of air to sulfur is maintained constant over a wide range of SO.sub.3 production rates, and the air is unheated during most production rates. The mixture of air and SO.sub.2 from the sulfur burner is cooled without increasing the volume of the gaseous mixture.
Type:
Grant
Filed:
June 18, 1992
Date of Patent:
September 14, 1993
Assignee:
The Chemithon Corporation
Inventors:
William G. Hankins, Burton Brooks, John C. Chittenden, William B. Sheats, Patrick J. Bader
Abstract: The present invention provides a flue gas conditioning system and method for generating conditioning agent used in the removal of entrained particles in a flue gas flow with an electrostatic precipitator. The invention involves the use of a catalytic converter movable between an operative position where the flue gas flows through the catalyst and converts SO.sub.2 contained in the flue gas to SO.sub.3 when conditioning agent is needed and an inoperative position where the flue gas does not flow through the catalyst when conditioning agent is no longer needed. The movable catalytic converter and related assembly may take variable configurations to accommodate various flue gas ductworks and space limitations.
Type:
Grant
Filed:
July 1, 1992
Date of Patent:
August 31, 1993
Assignee:
Wilhelm Environmental Technologies, Inc.