Abstract:
The invention relates to a method of making a mineral melt, the method comprising providing a circulating combustion chamber which comprises an upper zone, a lower zone and a base zone, injecting primary particulate fuel and particulate mineral material and primary combustion gas into the upper zone of the circulating combustion chamber, thereby at least partially combusting the primary particulate fuel and thereby melting the particulate mineral material to form a mineral melt and generating exhaust gases, injecting into the lower zone of the circulating combustion chamber, through at least one first burner, secondary combustion gas and gaseous fuel and secondary particulate fuel, wherein the secondary combustion gas and gaseous fuel and secondary particulate fuel are injected via a single first burner, wherein the amount of secondary combustion gas injected via each first burner is insufficient for stoichiometric combustion of the total amount of gaseous fuel and secondary particulate fuel injected via that first burner, and injecting tertiary combustion gas into the lower zone of the circulating combustion chamber, through at least one tertiary combustion gas injector, whereby the tertiary combustion gas enables completion of the combustion of the gaseous fuel and the secondary particulate fuel, separating the mineral melt from the hot exhaust gases so that the hot exhaust gases pass through an outlet in the circulating combustion chamber and the mineral melt collects in the base zone. The invention also relates to apparatus suitable for use in the method.
Abstract:
A furnace (10), firing pattern and method of operating a heater that employs a combination of hearth burners (46) and wall burners (56) for the cracking of hydrocarbons is described. The firing pattern leads to improvements in the uniformity of the coil metal (26) temperatures and vertical heat flux profiles over the firebox elevation. The hearth burners (46) operate with a stoichiometric excess of air while the wall burners (56) operate with less than the stoichiometric amount of air.
Abstract:
A furnace (10), firing pattern and method of operating a heater that employs a combination of hearth burners (46) and wall burners (56) for the cracking of hydrocarbons is described. The firing pattern leads to improvements in the uniformity of the coil metal (26) temperatures and vertical heat flux profiles over the firebox elevation. The hearth burners (46) operate with a stoichiometric excess of air while the wall burners (56) operate with less than the stoichiometric amount of air.
Abstract:
Emissions of NOx and CO are reduced from combustion devices such as coal-fired furnaces by increasing the stoichiometric ratio of burner (s) (30) having a lower average temperature and increasing the stoichiometric ratio of burner (s) (30) having a higher average temperature.
Abstract:
The present invention is related to methods and systems for preventing the release of nitrogen oxides with combustion flue gases emitted to the atmosphere. The invention is specifically directed to the removal of nitric oxide, nitrogen dioxide, and nitrous oxide from flue gas in stationary combustion systems. The methods of the invention improve efficiency of conventional reburning and advanced reburning processes by two key improvements, including the injection of a reducing agent into the reburning zone (16) and the use of promoters, which considerably enhance NOx control. The promoters are metal-containing compounds that can be added to the reducing agents. These improvements allow either one or two stages of reducing agent injection for greater NOx control (50).
Abstract:
A method for enhancing the minimization of NOx control in a circulating fluid bed steam generator (12) into which there is injected fuel, fluidizing air, a lower level of combustion air and an upper level of combustion air. The fuel is injected at a first location (30), the fluidizing air is injected at a second location (24), the lower level of combustion air is injected at a third location (50b) and the upper level of combustion air is injected at a fourth location (50a). In order to enhance the minimization of NOx control within a circulating fluid bed steam generator (12) the lower level combustion air (50b) as well as the upper level combustion air (50a) are each biased in the horizontal plane as well as the vertical plane so as to thereby control the lower level combustion air flow (50b) and the upper level combustion air flow (50a) such that local stoichiometries within the circulating fluid bed steam generator (12) are maintained within a range of 70 % stoichiometry to 90 % stoichiometry.
Abstract:
A method of optimizing operation of a furnace to control emission within a system. Each furnace zone inside of the furnace is associated with at least one exhaust zone. A signal indicative of an amount of byproduct exiting the furnace through at least one of the exhaust zones is received from one or more of the sensors. Based on this signal, an offending furnace zone is identified from among the plurality of furnace zones, the offending furnace zone including an oxygen level contributing to the amount of the byproduct. A relative adjustment of at least one of an amount of oxygen being introduced into the offending furnace zone, and an angular orientation of an oxygen injector introducing oxygen into the offending furnace zone relative to a focal region within the furnace can be initiated. The furnace may have structure to perform the method and may be part of a system.