Provided is an auxiliary burner for an electric furnace that has high iron scrap heating effect by appropriately and efficiently burning a solid fuel such as coal together with a gas fuel. An auxiliary burner for an electric furnace 100 has a structure in which a solid fuel injection tube 1, a gas fuel injection tube 2, and a combustion-supporting gas injection tube 3 are coaxially arranged in order from the center. The front end of the solid fuel injection tube 1 is located inside the gas fuel injection tube 2 to form, between the front end of the solid fuel injection tube 1 and the front end of the gas fuel injection tube 2, a first space 4 for solid fuel and gas fuel premixing surrounded by the front end portion of the gas fuel injection tube 2.

A combustion device includes: an ammonia injection nozzle having an injection port facing an internal space of a furnace; a pulverized coal injection nozzle having an injection port facing the internal space of the furnace; an adjustment mechanism that adjusts an injection flow rate of ammonia from the ammonia injection nozzle; and a control device that controls an operation of the adjustment mechanism in such a manner that the injection flow rate of ammonia from the ammonia injection nozzle is higher than an injection flow rate of pulverized coal from the pulverized coal injection nozzle.

A method for online monitoring and determining the calorific value of a solid fuel that is currently combusted in a boiler, that includes: on-line measuring the operational data of the boiler and of at least one mill during the operation 10 of the boiler; collecting the historical data; calculating the energy balances of the steam production system; iteratively determining the efficiency of the boiler by: determining sets of mill characteristics, the fuel mass flux, and the actual calorific value of the fuel for the historical data; training a model based on artificial intelligence algorithms to predict the calorific value using the historical data and measured operational data; determining in real time, using the trained model, the calorific value of the solid fuel that is currently combusted.

There is provided a continuous combustion system for iron particles. The system comprising a multi-annular combustion tube defining in cross-section at least three distinct passages from its inlet to its outlet. A first tube that is innermost, defines a first passage providing a primary air flow with suspended iron particles. A second tube, defines an inner annular space providing a secondary air flow, a pilot combustible flow, and an ignition point of a spark generator. A third tube defines a third passage comprises a swirl generator and provides a tertiary air flow. The tubes are nested in position within the multi-annular combustion tube. The system comprises a divergent nozzle at the outlet of the multi-annular combustion tube: a combustion reactor in fluid communication with the divergent nozzle, for the generation and stabilization of a turbulent iron flame that burns the iron particles and produces oxidized iron particles; and a cyclone.

There is provided a continuous combustion system for iron particles. The system comprising a multi-annular combustion tube defining in cross-section at least three distinct passages from its inlet to its outlet. A first tube that is innermost, defines a first passage providing a primary air flow with suspended iron particles. A second tube, defines an inner annular space providing a secondary air flow, a pilot combustible flow, and an ignition point of a spark generator. A third tube defines a third passage comprises a swirl generator and provides a tertiary air flow. The tubes are nested in position within the multi-annular combustion tube. The system comprises a divergent nozzle at the outlet of the multi-annular combustion tube: a combustion reactor in fluid communication with the divergent nozzle, for the generation and stabilization of a turbulent iron flame that burns the iron particles and produces oxidized iron particles; and a cyclone.

The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

The burner preferably exclusively burns substantially explosible solid fuels and preferably has instant ON-OFF thermostat control, wastes no energy preheating the enclosure or external air supply, achieves stable combustion the moment the powder-air mix is ignited in our burner, is used in the upward vertical mode except for oil burner retrofits, burns a solid fuel in a single-phase regime as if it were a vaporized liquid or gas, is designed to complete combustion within the burner housing itself rather than in a large, high temperature furnace enclosure which it feeds, has an ultra-short residence time requirement, is a recycle consuming burner with self-contained management of initially unburned particles, is much smaller, simpler and lower cost, has a wider dynamic range/turndown ratio, is more efficient in combustion completeness and thermal efficiency, and operates with air-fuel mix approximately at the flame speed.

A combined combustion burner and a combustion apparatus including the combined combustion burner. The combined combustion burner may include a center tube forming a center passage configured to supply cooling air, a fuel tube surrounding the center tube and forming a fuel passage through which premixed fuel mixed with solid fuel and primary air is sprayed, a secondary tube surrounding the fuel tube and forming a secondary passage through which secondary air is sprayed, and an additional spray nozzle inserted inside the center tube and configured to spray auxiliary fuel containing ammonia.

A burner includes a multiple pipe including an inner pipe and outer pipes. The inner pipe and the outer pipes are located coaxially about a burner axis. The multiple pipe includes: a fuel discharge port located at a downstream end of the inner pipe and discharges a fuel-air mixture containing main fuel and primary combustion air which have been supplied to the inner pipe; a secondary air outlet which is located at an outer peripheral side of the fuel discharge port and emits secondary combustion air which has been supplied to between the outer pipes; and an annular gas fuel outlet which is located between the fuel discharge port and the secondary air outlet and emits gas fuel as auxiliary fuel which has been supplied to between the inner pipe and the outer pipes, toward a boundary between flow of the fuel-air mixture and flow of the secondary combustion air.

A burner includes: a first nozzle including a main fuel outlet that discharges a fuel-air mixture containing main fuel and primary combustion air and a flame holding plate around the outlet; and a second nozzle located coaxially with the first and including a secondary air outlet that emits secondary combustion air at an outer peripheral side of the main fuel outlet; and auxiliary fuel injection nozzles extending along an outer surface of the first nozzle in parallel with a burner axis. The auxiliary fuel injection nozzles include: auxiliary fuel outlets along an outer peripheral edge of the flame holding plate; or auxiliary fuel outlets inside the outer peripheral edge of the flame holding plate and outside an inner peripheral edge of the flame holding plate. The auxiliary fuel outlets discharge gas fuel as auxiliary fuel toward a boundary between flows of the fuel-air mixture and the secondary combustion air.