Atomized Liquid Fuel Injection for Sintering Bed Combustion
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Solution Overview
Problem
Conventional techniques for producing sintered ore in a downward suction type sintering machine face challenges such as insufficient combustion leading to low sintered ore strength and yield, due to issues like backfire, oxygen deficiency, and increased gas flow resistance, which hinder the control of maximum temperature and holding time in the high-temperature zone.
Innovation Solution
A method involving the supply of atomized liquid fuel with a particle size of 100 µm or less above the sintering bed, diluted to not more than the lower limit concentration of combustion, which is vaporized and transported to the combustion and melting zone, allowing controlled combustion and increased holding time without igniting on the surface, thereby enhancing sintered ore strength and yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the pallet traveling speed is increased to improve productivity, then the production rate increases, but the holding time in high-temperature region decreases leading to insufficient sintering and reduced cold strength
Solution Approach 1:
The liquid fuel is supplied and vaporized in advance before the material reaches the main combustion zone, pre-heating the sintering raw material and extending the effective high-temperature exposure time without increasing the pallet traveling speed
Solution Approach 2:
Liquid fuel acts as an intermediary energy source that bridges the gap between the ignition furnace output and the main combustion zone, providing additional heat input that compensates for the reduced holding time at high temperatures
2Strength
If gas fuel is supplied at high concentration to increase temperature and holding time, then sintered ore strength improves, but backfire and explosion risks increase
Solution Approach 1:
The fuel concentration parameter is changed from high concentration gas fuel to diluted liquid fuel vapor, which provides sufficient heat for sintering while eliminating the backfire and explosion hazards associated with high-concentration gas fuel
Solution Approach 2:
Liquid fuel is used as a disposable, easily controllable energy source that can be rapidly introduced and consumed without creating persistent safety hazards, replacing the dangerous high-concentration gas fuel system
3Productivity
If the sintering bed thickness is increased to improve yield, then more material is processed, but gas flow resistance increases reducing combustion efficiency
Solution Approach 1:
Liquid fuel vapor acts as an intermediary that provides heat directly to the sintering raw material particles, bypassing the gas flow resistance issue that plagues conventional thick-bed sintering operations
Solution Approach 2:
The liquid fuel is supplied locally to specific zones within the sintering bed where additional heat is needed, creating localized high-temperature regions that ensure complete sintering even in thick beds where gas flow resistance would otherwise prevent adequate combustion
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively increases the strength and yield of sintered ore by controlling the maximum temperature and holding time in the high-temperature zone, preventing backfires and ensuring stable operation, while maintaining safe and efficient combustion.
Implementation Method 1
atomized liquid fuel...which is vaporized and transported to the combustion and melting zone
Implementation Method 2
carbonaceous material in the sintering bed is successively combusted. By combustion heat generated at this stage
Implementation Method 3
downward air suction is performed using wind boxes located below the pallet
Data Source
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AI summary
There are provided a method for producing a sintered ore and a sintering machine, the method being capable of safely producing a high-strength and a high-quality sintered ore with high yield using a downward suction type sintering machine. In a method for producing a sintered ore which includes charging a sintering raw material containing a fine ore and a carbonaceous material on a circular traveling pallet 8 to form a sintering bed 9, igniting the carbonaceous material in the formed sintering bed by an ignition furnace, and sucking air through a wind box provided below the pallet to produce the sintered ore, after the sintering bed 9 is ignited by the ignition furnace, a liquid fuel is atomized to have a particle size of 100 µm or less, is supplied at an upper portion of the sintering bed 9, and while being diluted to not more than a lower limit of combustion at ordinal temperature, is supplied into the sintering bed 9 from above the sintering bed 9. A sintering machine includes a liquid fuel spray device which sprays a liquid fuel on a sintering bed at a downstream side of an ignition furnace.