摘要:
A fuel injector has an inner pipe within an outer pipe. The distal end of the inner pipe is set back from the distal end of the outer pipe to create a flame stabilization and mixing zone. A combustible gas and air mixture injected through the outer pipe forms a flame shroud around a gas stream injected through the inner pipe. This injector provides increased flame penetration and improved NO.sub.x reduction particularly when used to inject a flame shrouded gas stream into regions of the furnace at which the flue gas is at a temperature not greater than 2400.degree. F.
摘要:
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.
摘要翻译:一种还原NOx的方法决定了炉内温度低于2600°F的区域内的NOx浓度分布。流体燃料流注入至少一个具有较高NOx浓度的区域,以使流体燃料在其中混合 与烟气。 流体燃料是天然气,氢,C x H y化合物,C x H y O z化合物或主要由那些化合物混合的物质,其量足以促进烟气中的氮氧化物与流体燃料之间的反应,以便基本上减少 烟气 注入流体燃料的喷射器可以是可移动的并且可以具有阀或偏转器,以帮助将流体燃料引导到具有较高NOx浓度的区域。
摘要:
In a furnace having a primary combustion zone for combustion of a fuel and oxidant, an in-furnace method for reducing nitrogen oxides in combustion products generated in the primary combustion zone in which at least one fluid fuel selected from the group consisting of natural gas, hydrogen, CxHy compounds, CxHyOz compounds and mixtures thereof in an amount in a range of about 2.0% to about 25% of a total heat input to the furnace and at least one nitrogenous compound selected from the group consisting of ammonia, amines, urea, cyanuric acid and mixtures thereof are injected into the furnace downstream of the primary combustion zone, forming an overall fuel-lean NOx-reduction zone.
摘要翻译:在具有用于燃烧和氧化剂燃烧的初级燃烧区的炉子中,用于还原在主燃烧区产生的燃烧产物中的氮氧化物的炉内方法,其中至少一种选自天然气, 氢,C x H y化合物,C x H y O z化合物及其混合物,其量为输入炉内总热量的约2.0%至约25%,以及至少一种选自氨,胺,脲, 将氰尿酸及其混合物注入到主燃烧区下游的炉中,形成总体贫燃氮氧化物还原区。
摘要:
A process and apparatus for combustion of a solid carbonaceous material, for example coal, in which a mixture of the solid carbonaceous material and combustion air is injected into a combustion chamber and ignited, thereby forming a fuel-lean primary combustion zone. A gaseous fuel is injected into the combustion chamber in a region downstream of the primary combustion zone, thereby forming a fuel-lean secondary combustion zone. Temperature in the secondary combustion zone is in the range of about 1800.degree. F. to 2400.degree. F.
摘要:
An apparatus and method for reducing nitrogen oxide emissions from furnace flue gas is provided in which natural gas or other fluid fuel which has little or no fixed nitrogen is introduced into the upper portion of the furnace. The fuel diffuses by laminar or turbulent diffusion into oxygen-rich flue gas where it reacts with oxygen and nitric oxide to form CO.sub.2, H.sub.2 O and N.sub.2, thus reducing the nitrogen oxide emissions from the furnace. In this manner, the amount of nitrogen oxide in the flue gas is reduced. The apparatus and method can be easily applied to new furnaces or retrofitted on existing furnaces.
摘要:
In a method of determining amounts of condensable species present in a gas containing condensable species a probe is placed into a gas containing condensable species. The probe has a plurality of spaced apart contacts on an outer non-conductive surface. That surface is heated at a selected heating rate and then cooled at a selected cooling rate over a selected time period. During that time period current flow between the contacts and the temperature of the non-conductive surface is monitored over the selected time period. Peaks in a plot of the current flow over the selected time period and the temperature for the time corresponding to each peak are then correlated to the condensable species has a kinetic dew point at each identified temperature. The identified temperature for each identified species is compared to a predetermined correlation of dew point temperature and concentration for that species to determine the concentration of that condensable species present in the gas.
摘要:
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.
摘要:
An apparatus and method for reducing nitrogen oxide emissions from the products of combustion is provided in which a vortex generator introduces natural gas, or other fluid fuel into the upper portion of a combustion device. The fuel introduced forms vortices, such as vortex rings, and the fuel reacts with the nitrogen oxide in the combustion products to form ammonia-like compounds, hydrogen cyanide and similar compounds, and nitrogen. The ammonia and cyanide-like fragments react with additional amounts of nitrogen oxide in the combustion products to form nitrogen gas, water vapor and carbon dioxide. The vortex rings can be controlled and will maintain their integrity longer than puffs or simple jets of fuel.
摘要:
Nitrogen oxide and dioxide content of flue gas from combustion devices is reduced by mixing combustion air and a gas or volatilized fuel in proportions below the lower combustible limit of the mixture and utilizing that mixture for at least a part of the combustion air supplied to the devices. The mixture may take the form of air contaminated with a fuel.
摘要:
A method of recycling fly ash as slag in a wet bottom furnace is described. The furnace may have a cyclone furnace, a pulverized coal furnace, or any other type of furnace producing wet slag. All or part of the collected fly ash is collected and returned to the furnace and combined with enough fuel to melt the ash. Melted ash directed against a wall, floor or side of the cyclone or furnace will flow to the bottom of the furnace so as to facilitate the liquid slag. The fly ash may be collected by an electrostatic precipitator, baghouse, cyclone (multiclone) or other device. The fly ash may be returned to the furnace or the cyclone using air, flue gas, steam, fuel, or other gas as a carrier.