Consolidated Natural Gas Service Company, Inc.

Energy Systems Associates

Duquesne Light Company

Esa Corrosion Solutions, LLC

Other

Breen Energy Solutions

Esa Environmental Solutions, Inc.

Duquesne Light Company and Energy Systems Associates

Cinergy Technology, Inc.

James E Gabrielson

Bernard P Breen

John P Bionda

Anthony Hallo

Robert A Schrecengost

Roger W Glickert

David Eden

Dennis Tobias

Harjit Singh Hura

James C McMichael

John W Bjerklie

John M Koltick, Jr

John H Pohl

Howard B Lange

Jeffrey J Sweterlitsch

Steven E Winberg

Aziz A Lookman

Keith S Lochart

Joseph A Urich

Gerard F Gretz

Edward D Kramer

Eugene Berkau

Joseph Cavello

Ralph W McConnell

Steve Winberg

In a method of removing metals such as mercury from flue gas produced by combustion devices, ammonia and optionally carbon monoxide are injected into the flue gas in a manner so that there are sufficient amounts of these materials in the flue gas when the flue gas is at a temperature of from 900&deg; F. to 1350&deg; F. to oxidize the metals within the flue gas. The oxidized metals are then attracted to particulates present in the flue gas. These particulates bound with oxidized metals are removed from the flue gas by a particulate removal device such as an electrostatic precipitator or baghouse.

Control of mercury and other elemental metal emissions from combustion devices by oxidation

A tubular probe has spaced apart bands or patches of the same material as the probe body attached to the probe body by an electrically insulating, high temperature material. A series of cooling tubes are provided within the probe body to direct cold air to the regions near each band. One or more probes is placed in a furnace or boiler above the ammonia injection zone. When ammonium bisulfate forms on the probe it completes an electrical circuit between the probe body and the bands and will also cause corrosion of the probe. The presence of ammonium bisulfate is detected by a change in resistance between the bands and the probe body. Electrochemical noise is generated during the corrosion process. A corrosion rate can be determined from the level or amount of electrochemical noise that is detected.

Detection, measurement and control of ammonia in flue gas

A method for monitoring and reducing corrosion in furnace boiler tubes measures electrochemical noise associated with corrosion mechanisms while corrosion is occurring at the surface of the tubes as they are exposed to combustion products. This noise is detected using a probe at the boiler waterwall surface that is connected to a corrosion monitor. The monitor contains a computer and software which determines a corrosion rate from the measured electrochemical noise. That rate is compared to a standard to determine if the rate is within acceptable limits. If not, the operator of the furnace or an Adaptive Process Controller (APC) is notified and adjusts one or more burners to change the combustion products that are responsible for the corrosion. Such an adjustment could be made by changing the amount of air or fuel being provided to the burner or other air slots or air ports. After that adjustment is made the furnace emissions could be checked for NOx, SOx and particulate emissions and further adjustments could be made to the burners to reduce those emissions.

Method of monitoring and controlling corrosion of furnace boiler tubes

A method is provided for controlling the operation of a furnace. A furnace generally includes a boiler having a combustion zone, a plurality of burners burning a mixture of fuel and air in the combustion zone producing a gaseous by-product, and an electrostatic precipitator in fluid communication with the boiler removing particulates from the gaseous by-products. The method includes the steps of monitoring operating conditions of the electrostatic precipitator on a section-by-section basis, and controlling a select one or more of the burners based upon the section-by-section monitored operating conditions.

Method of operating a furnace based upon electrostatic precipitator operation

In an improved method for reducing nitrogen oxide emissions from a furnace wherein at least one injector is attached to the furnace above the primary combustion zone a biomass or biowaste and water slurry is injected into the flue gas through the injectors. The biowaste or a biomass material can be supplemented with a fixed nitrogen source.

Method for NOx reduction by upper furnace injection of biofuel water slurry

An in-furnace method and apparatus reduces nitrogen oxides in flue gas by injecting an oil water emulsion into flue gas so that the oil and water mixes with said flue gas. The emulsion has from 35% to 80% water and is injected in sufficient quantities to provide enough oil to promote a reaction between the nitrogen oxides in the flue gas and the oil, so as to reduce nitrogen oxide content of the flue gas and to maintain overall fuel lean conditions above the primary combustion zone. The emulsion preferably is atomized before injection and may also be injected in jet streams. Other materials such as limestone, ammonia and urea could be added to the oil water emulsion prior to injection.

Use of oil water emulsion as a reburn fuel

In a method of reducing NO.sub.x a water-fixed nitrogen solution is injected into a furnace near the exit from the furnace where the temperatures exceed 2000.degree. F. and combustion is occurring. Preferably the solution is injected through a combination of atomizing nozzles and spray jets into a region of the furnace which does not exceed 2700.degree. F. A calcium compound to react with sulfur dioxide may also be added.

Method for NO.sub.x reduction by upper furnace injection of solutions of

A method of reducing NO.sub.x determines an NO.sub.x concentration profile within a zone of the furnace which is at a temperature below 2600.degree. F. A stream of fluid fuel is injected into at least one region of relatively high NO.sub.x concentration so that the fluid fuel mixes therein with the flue gas. The fluid fuel is natural gas, hydrogen, C.sub.x H.sub.y compounds, C.sub.x H.sub.y O.sub.z compounds or mixtures primarily of those compounds, in sufficient quantity to promote a reaction between nitrogen oxide in the flue gas and the fluid fuel, so as to substantially reduce nitrogen oxide content of the flue gas. The injector through which the fluid fuel is injected can be moveable and may have valves or deflectors to aid in directing the fluid fuel to regions of relatively high NO.sub.x concentration.

Apparatus and method for NO.sub.x reduction by selective injection of

A method for reducing the rate of side wall corrosion in a coal-fired utility boiler. A plurality of side wall slots are provided in the side walls of the boiler so that a protective layer of air may be introduced through the slots and propelled upward by the updraft from the burners.

Corrosion protection for utility boiler side walls

In a method for reducing NOx in the flue gas a coal water slurry is injected into the furnace above the primary combustion zone into a region having a temperature from 1800.degree. F. to 2700.degree. F. The slurry is preferably injected through atomizers and through injectors that introduce a continuous stream. Lime, ammonia, urea and completion air can also be injected.

Method and apparatus for nox reduction by upper furnace injection of

An improved pulverized coal burner that reduces the formation of nitrogen oxides. The coal burner includes fuel splitters that separate a mixture of primary air and coal into a plurality of streams while the mixture is discharged through a diffuser having a plurality of partially open areas and a plurality of blocked areas. After passing through the diffuser, the plurality of streams are discharged into a furnace to be burned. The plurality of partially open areas and blocked areas are created by removing sections of the diffuser and replacing the removed sections with fuel spiders. Creation of these discrete streams delays mixing with secondary air. Because primary air is supplied in sub-stoichiometric quantities, the coal in these split streams will be burned under fuel-rich conditions for the first 100 to 200 milliseconds of combustion, until the delayed mixing of secondary air occurs. Combustion in a fuel-rich environment retards formation of nitrogen oxides in two ways. First, nitrogen that is part of the volatile matter that is evolved during the ears stages of combustion will tend to form molecular nitrogen rather than react with oxygen to form nitrogen oxides. Second, an oxygen deficiency will reduce formation of nitrogen oxides from atmospheric nitrogen. Two variations of bypass conduits are disclosed that allow a portion of the mixture of primary air and coal to bypass the diffuser and discharge into the furnace.

Split flame burner for reducing NO.sub.x formation

An improved method and apparatus for supplying combustion air in a roof-fired furnace. Part of the combustion air, overfire air, enters through the roof of a roof-fired furnace at positions separate from the coal burners. The separated entry of overfire air ensures that the initial stages of combustion occur in a fuel-rich environment. A fuel-rich environment during the early stages of combustion favors the formation of molecular nitrogen and disfavors the formation of nitrogen oxides during combustion. The overfire air flows roughly parallel to the flow of combustion products emanating from the coal burners. The overfire air can be angled by vanes either slightly towards or slightly away from the combustion products, depending on how long combustion needs to be retarded in order to inhibit the formation of nitrogen oxides.

Reducing NOX emissions from a roof-fired furnace using separated

An improved pulverized coal burner that reduces the formation of nitrogen oxides. The coal burner includes fuel splitters that separate a mixture of primary air and coal into a plurality of streams while the mixture is discharged through a diffuser having a plurality of partially open areas and a plurality of blocked areas. After passing through the diffuser, the plurality of streams are discharged into a furnace to be burned. The plurality of partially open areas and blocked areas are created by removing sections of the diffuser and replacing the removed sections with fuel splitters. Creation of these discrete streams delays mixing with secondary air. Because primary air is supplied in sub-stoichiometric quantities, the coal in these split streams will be burned under fuel-rich conditions for the first 100 to 200 milliseconds of combustion, until the delayed mixing of secondary air occurs. Combustion in a fuel-rich environment retards formation of nitrogen oxides in two ways. First, nitrogen that is part of the volatile matter that is evolved during the early stages of combustion will tend to form molecular nitrogen rather than react with oxygen to form nitrogen oxides. Second, an oxygen deficiency will reduce formation of nitrogen oxides from atmospheric nitrogen.

Split flame burner for reducing NOx formation

The present invention provides an apparatus and method to improve the performance of a variety of particulate collection devices. Gaseous ammonia is injected by one or more injectors into a waste gas upstream from a particulate collection device. The amount of ammonia injected from each injector is controlled so that the local concentration of ammonia in the waste gas is approximately the same as the corresponding local concentration of sulfur trioxide in the waste gas. The flow of ammonia from each injector is controlled by measuring several local sulfur trioxide concentrations in the waste stream after the ammonia has been injected. The sulfur trioxide can occur naturally or result from injection. By keeping the concentration of ammonia approximately equal to the concentration of sulfur trioxide, ammonia and sulfur trioxide react to form a liquid product. This liquid reaction product coats the surfaces of particles entrained in the gas stream. Once coated, the particles' electrical conductivity is altered so that they are more easily collected by devices employing electrostatic attraction. The liquid coating also causes the particles to agglomerate and these larger agglomerates are easier to collect.

Apparatus and method for enhancing the performance of a particulate

A method and apparatus for reducing the formation of nitrogen oxides during combustion in a roof-fired furnace is disclosed. By blocking at least some of the fuel nozzles associated with a roof-fired burner while leaving open the secondary air openings associated with the blocked fuel nozzles, reduction in NOX emissions from roof-fired furnaces is accomplished. This blocking results in the creation of a localized fuel-rich or just slightly fuel-lean environment near open fuel nozzles because part of the secondary air needed for combustion is being added at a location distant from where the initial combustion occurs. By creating a localized fuel-rich or slightly fuel-lean environment near the open fuel nozzles, the initial stages of combustion occur with little or no excess oxygen present. Because much of the fuel-bound nitrogen is liberated during the initial stages of combustion, it will preferentially react to form molecular nitrogen rather than nitrogen oxides because of the lack of available oxygen. Further, by the time all the secondary air is mixed with the pulverized coal to complete substantially the combustion, the flame temperature will have been sufficiently lowered by heat transfer to the boiler tubes that thermal formation of nitrogen oxides will be reduced. This invention works well in those roof-fired furnaces where individual burners are composed of multiple fuel nozzles and the fuel nozzles eject primary air and fuel between boiler tubes which form the furnace roof.

Growing community of inventors

Plymouth, MN, United States of America

James E Gabrielson