Series preheating method and series preheating system for coal gas of sintering ignition furnace

Abstract

The invention belongs to the field of combustion equipment and provides a series preheating method for combustion air and coal gas for a sintering ignition furnace. The series preheating method comprises the following steps: connecting a combustion air heat exchanger with a coal gas heat exchanger in series and combusting coal gas as a fuel in a hearth of a preheating furnace to generate flue gas; firstly, preheating the combustion air for the ignition furnace by using high-temperature flue gas, then preheating the coal gas for the ignition furnace by using low-temperature flue gas to ensure that the combustion air for the ignition furnace is preheated to 200-350 DEG C, and the coal gas for the ignition furnace is preheated to 150-300 DEG C, and then feeding into the sintering ignition furnace, performing heat convection on the combustion air for the ignition furnace and the high-temperature flue gas; performing heat convection on the coal gas for the ignition furnace and the low-temperature flue gas. The series preheating method disclosed by the invention can be applicable to the sintering ignition furnace which takes low-heating-value coal gas as a fuel, an ignition effect is improved, and the sintering ore quality is ensured. As the low-heating-value coal gas is used as the fuel, the energy consumption is reduced. Double-stroke tubular heat exchangers are used for heat exchange, so that the heat exchangers and the heat exchange areas are reasonably configured, the heat exchange effect is good, the heat exchange coefficient can be up to 20kcal / m2.h.DEG C, and the service life of the heat exchanger is prolonged.

Description

Technical field [0001] The invention belongs to the field of combustion equipment, and particularly relates to a method and system for preheating combustion-supporting air and gas for a sintering ignition furnace. Background technique [0002] Sintering is to mix iron ore, fuel, solvent, etc. according to a certain proportion to make a mixed ore. The segregation is distributed on the sintering machine trolley, which is ignited by an ignition furnace and sintered at a high temperature to produce sintered ore. Sinter is the main raw material for blast furnace ironmaking. The sintering furnace is an important part of the sintering machine equipment system. The sintering ignition furnace is set at the head of the sintering machine, and provides heat through fuel combustion to ignite the surface layer of the mixed ore to ensure the normal progress of the suction sintering process. The sintering ignition furnace can use coal gas, oil, pulverized coal, etc. as fuel. The existing sinte...

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Problems solved by technology

However, the use of low calorific value gas has low ignition temperature, high energy consumption, and poor ignition effect. A small number of existing sintering furnaces use on-board double preheating or single preheating methods to preheat combustion air and low calorific value gas, or only preheat Heated combustion-supporting air or gas, but limited by the space of the sintering machine operating platform, it cannot be applied to large sintering machines (usually 180m 2 above sintering machine)

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