阅读说明：本技术 保证高烟煤配比的喷吹方法 (Blowing method for ensuring high soft coal ratio ) 是由 李勇波 余珊珊 郑华伟 朱义斌 伍昌越 叶纪康 于 2020-11-17 设计创作，主要内容包括：本发明涉及冶炼领域,公开了一种高烟煤配比的喷吹方法,包括如下步骤：A)在中速磨入口位置设置第一测试取样孔；B)采用红外测温仪对步骤A)设置的第一测试取样孔进行烟气温度监测；C)当第一测试取样孔的烟气温度低于预设温度时,提高热风炉和烟气炉内的烟气温度,直至第一测试取样孔处的烟气温度高于预设温度。本发明高烟煤配比的喷吹方法,保证热风炉和烟气炉的烧炉温度,提高废气温度,进而控制原煤水分,保证高烟煤配比喷吹。(The invention relates to the field of smelting, and discloses a high-bituminous coal proportioning injection method, which comprises the following steps: A) arranging a first test sampling hole at the inlet of the medium-speed mill; B) monitoring the flue gas temperature of the first test sampling hole arranged in the step A) by using an infrared thermometer; C) and when the smoke temperature of the first test sampling hole is lower than the preset temperature, increasing the smoke temperature in the hot blast stove and the smoke stove until the smoke temperature at the first test sampling hole is higher than the preset temperature. The method for injecting the high-bituminous coal in proportion ensures the burning temperature of the hot blast stove and the flue gas stove, improves the temperature of the waste gas, further controls the moisture of the raw coal and ensures the high-bituminous coal in proportion to be injected.)

1. A blowing method for high bituminous coal proportioning is characterized in that: the method comprises the following steps:

A) arranging a first test sampling hole at the inlet of the medium-speed mill;

B) monitoring the smoke temperature of the first test sampling hole arranged in the step A) by using an infrared thermometer;

C) and when the smoke temperature of the first test sampling hole is lower than the preset temperature, increasing the smoke temperature in the hot blast stove and the smoke stove until the smoke temperature at the first test sampling hole is higher than the preset temperature.

2. The method of injecting high bituminous coal at a high bituminous coal ratio according to claim 1, wherein: arranging a second testing sampling hole at the outlet position of the hot blast stove, in the step C), when the smoke temperature of the first testing sampling hole is lower than the preset temperature, entering the step C1), adjusting a combustion air flow regulating valve of the hot blast stove arranged on the hot blast stove to increase the combustion air flow, adjusting the air-fuel ratio of the hot blast stove, detecting the smoke temperature of the second testing sampling hole by an infrared thermometer, when the smoke temperature can reach the preset temperature, completing the adjustment, when the smoke temperature can not reach the preset temperature, entering the step C2), adjusting a gas flow regulating valve of the hot blast stove arranged on the hot blast stove to increase the gas flow, continuously heating the smoke temperature in the hot blast stove, detecting the smoke temperature of the second testing sampling hole by the infrared thermometer, when the smoke temperature can reach the preset temperature, completing the adjustment, and when the smoke temperature can not reach the preset temperature, and continuing to alternately perform the step C1) and the step C2) until the temperature of the smoke of the second test sampling hole can reach the preset temperature.

3. The method of injecting high bituminous coal at a high bituminous coal ratio according to claim 1, wherein: in the step C), when the flue gas temperature of the first test sampling hole is lower than the preset temperature, the step C3) is performed, a flue gas furnace combustion air flow regulating valve arranged on the flue gas furnace is regulated to increase the combustion air flow, the air-coal ratio of the flue gas furnace is adjusted upwards, when the flue gas temperature of the first test sampling hole can reach the preset temperature, the regulation is completed, when the flue gas temperature can not reach the preset temperature, the step C4 is performed, a flue gas furnace gas flow regulating valve arranged on the flue gas furnace is regulated to increase the gas flow, the flue gas temperature in the flue gas furnace is continuously heated, when the flue gas temperature can reach the preset temperature, the regulation is completed, and when the flue gas temperature can not reach the preset temperature, the step C3) and the step C4) are continuously performed alternately until the flue gas temperature can reach the preset temperature.

4. The method of injecting high bituminous coal according to claim 1, 2, or 3, wherein: the preset temperature is 280-300 ℃.

Technical Field

The invention relates to the field of smelting, in particular to a blowing method for ensuring the proportion of high bituminous coal.

Background

In order to further reduce the iron-making cost, the iron-making plant carries out great adjustment on the coal injection structure of the blast furnace, the proportion of high-volatile bituminous coal is improved to 40 percent from 15 percent at present, the average of dry ash-free-base volatile components of the mixed coal in the whole plant is estimated to be 18 percent after adjustment, and the moisture of the mixed raw coal is 14 percent. Under the premise of reducing the cost of iron making, the large coal ratio injection is required to be realized, and the coal ratio is required to reach more than 170 kg/t. The bituminous coal contains 18-20% of water and the anthracite contains about 11% of water, when the ratio of the bituminous coal reaches 40% and the ratio of the anthracite reaches 60%, the moisture of raw coal of the mixed coal reaches about 14%, and at the moment, the moisture of the raw coal is controlled to be below 2% if the large coal ratio is ensured to be injected and the lower fuel ratio is ensured.

Therefore, the high water content of the mixed coal seriously restricts the propelling of the large coal ratio injection work of the high-proportion bituminous coal. On the premise that the replacement of a blowing equipment system is difficult, the moisture of raw coal needs to be controlled through process parameters.

In the adjustment improvement of the existing blast furnace coal injection structure, the following technical scheme is mainly adopted:

the application of the wind-coal ratio technology published by Zhang Xin in Lai Steel science and technology 167(5) (2013) in coal injection production is mentioned, the iron works of Xinjiang company increases the milling capacity of a medium-speed mill from 30t/h to 40t/h by drawing a trend chart of the wind-coal ratio of the medium-speed mill, wherein the temperature of a medium-speed mill coarse powder separator is controlled to be 92-95 ℃, the temperature of mill entering wind is controlled to be 260-300 ℃, and the wind rate is 0-15000m³At the time of/h, the powder production amount is increased with the increase of the air volume. The literature proposes an idea of controlling the air-coal ratio, but does not relate to a method for controlling the grinding air temperature.

The operating experience of the blast furnace with high proportion of bituminous coal injected by eight steels and the coke-saving effect of the blast furnace with high proportion of bituminous coal injected by eight steels published in the Chinese metallurgy 1(56) 2002 of Liangwenxin and Wang Hongchong chapter mainly show that the high proportion of bituminous coal injected is beneficial to smelting low-silicon pig iron, the combustion performance of pulverized coal is improved, the thermal lag time in the operation of the blast furnace is prolonged, and simultaneously, the high combustion rate of the pulverized coal is ensured while the air permeability in the furnace is ensured, and the air speed of a tuyere and the good performance of furnace burden are also ensured. The literature suggests the benefits of high proportion bituminous coal injection and matching blast furnace operating guidelines, but no mention is made of methods for water content control of coal fines.

3200m published in Shanxi metallurgy of Liu Li soldier, Wang Sung Yi, Miao Xinhai, 4(132) 2011³3200m is explained in the technical characteristics of a blast furnace coal injection system³The blast furnace coal injection system is technically characterized in that the coal injection system is designed according to the mixed injection of bituminous coal and anthracite, the powder preparation system is designed according to the strong explosive bituminous coal, the maximum coal injection ratio is 250kg/t, and the mass concentration of the coal powder discharged by tail gas is less than or equal to 30mg/m³After the coal injection system is put into operation, the operation is normal, the proportion of bituminous coal reaches 40%, and the blast furnace injection effect is good. The literature suggests a limit to the improvement of bituminous coals, but it starts mainly from the equipment modification aspect and does not go through the relevant means of process adjustment.

The improvement direction of the blast furnace coal injection technology published in iron and steel 10(31) 1996 mainly indicates the improvement direction of the blast furnace coal injection technology, indicates that the coal storage capacity needs to be increased in a coal yard, realizes automatic coal blending, adopts a full negative pressure process of medium-speed grinding for powder preparation and primary cloth bag for powder collection, and adopts safe explosion-proof measures when bituminous coal and mixed coal are injected. The computer control technology is used to raise the automation level of coal injection, and the oxygen coal gun and stokehole oxygen supply and safety control technology are used to realize coal ratio over 120kg/t economically, effectively and safely. This document addresses the explosion-proof problem of coal injection safety, but does not discuss the problem of water content in the injected raw coal.

Therefore, the prior art fails to relate to a control method for controlling the water content of the pulverized coal at the outlet of the medium-speed mill according to the air-coal ratio of the flue gas of the hot blast stove.

Disclosure of Invention

The invention aims to provide a method for injecting high-bituminous coal in proportion, aiming at the defects of the technology, so that the firing temperatures of a hot blast stove and a flue gas stove are ensured, the temperature of waste gas is increased, the moisture of raw coal is further controlled, and the high-bituminous coal is injected in proportion.

In order to achieve the aim, the invention discloses a high-bituminous coal proportioning injection method, which comprises the following steps:

A) arranging a first test sampling hole at the inlet of the medium-speed mill;

B) monitoring the smoke temperature of the first test sampling hole arranged in the step A) by using an infrared thermometer;

C) and when the smoke temperature of the first test sampling hole is lower than the preset temperature, increasing the smoke temperature in the hot blast stove and the smoke stove until the smoke temperature at the first test sampling hole is higher than the preset temperature.

Preferably, a second test sampling hole is arranged at the outlet position of the hot blast stove, in the step C), when the smoke temperature of the first test sampling hole is lower than the preset temperature, the step C1) is carried out, a combustion air flow regulating valve of the hot blast stove arranged on the hot blast stove is regulated to increase the combustion air flow, the air-fuel ratio of the hot blast stove is adjusted upwards, the smoke temperature of the second test sampling hole is detected through an infrared thermometer, when the smoke temperature can reach the preset temperature, the regulation is finished, when the smoke temperature can not reach the preset temperature, the step C2 is carried out, the gas flow regulating valve of the hot blast stove arranged on the hot blast stove is regulated to increase the gas flow, the smoke temperature in the hot blast stove is continuously increased, the smoke temperature of the second test sampling hole is detected through the infrared thermometer, when the smoke temperature can reach the preset temperature, the regulation is finished, when the smoke temperature can not, and continuing to alternately perform the step C1) and the step C2) until the temperature of the smoke of the second test sampling hole can reach the preset temperature.

Preferably, in the step C), when the flue gas temperature of the first test sampling hole is lower than the preset temperature, the step C3) is performed, a combustion air flow regulating valve of the flue gas furnace arranged on the flue gas furnace is regulated to increase the combustion air flow, the air-coal ratio of the flue gas furnace is adjusted upwards, when the flue gas temperature of the first test sampling hole can reach the preset temperature, the regulation is completed, when the flue gas temperature can not reach the preset temperature, the step C4 is performed, a flue gas flow regulating valve arranged on the flue gas furnace is regulated to increase the gas flow, the flue gas temperature in the flue gas furnace is continuously heated, when the flue gas temperature can reach the preset temperature, the regulation is completed, and when the flue gas temperature can not reach the preset temperature, the steps C3) and C4) are continuously performed alternately until the flue gas temperature can reach the preset temperature.

Preferably, the preset temperature is 280-300 ℃.

Compared with the prior art, the invention has the following advantages:

1. the burning temperature of the hot blast stove and the flue gas stove is ensured, the temperature of the waste gas is improved, the moisture of the raw coal is further controlled, and the high soft coal is injected according to the proportion.

Detailed Description

The present invention will be described in further detail with reference to specific examples.

The invention relates to a blowing method for high bituminous coal proportion, which comprises the following steps:

A) arranging a first test sampling hole at the inlet of the medium-speed mill;

B) monitoring the flue gas temperature of the first test sampling hole arranged in the step A) by using an infrared thermometer;

C) when the temperature of the flue gas of the first test sampling hole is lower than the preset temperature, the temperature of the flue gas in the hot blast stove and the temperature of the flue gas in the flue gas stove are increased until the temperature of the flue gas at the first test sampling hole is higher than the preset temperature, and the preset temperature is 280-300 ℃.

Wherein, a second testing sampling hole is arranged at the outlet position of the hot blast stove, in the step C), when the smoke temperature of the first testing sampling hole is lower than the preset temperature, the step C1) is carried out, a combustion air flow regulating valve of the hot blast stove arranged on the hot blast stove is regulated to increase the combustion air flow, the air-fuel ratio of the hot blast stove is adjusted upwards, the smoke temperature of the second testing sampling hole is detected by an infrared thermometer, when the smoke temperature can reach the preset temperature, the regulation is finished, when the smoke temperature can not reach the preset temperature, the step C2 is carried out, the gas flow regulating valve of the hot blast stove arranged on the hot blast stove is regulated to increase the gas flow, the smoke temperature in the hot blast stove is continuously increased, the smoke temperature of the second testing sampling hole is detected by the infrared thermometer, when the smoke temperature can reach the preset temperature, the regulation is finished, when the smoke temperature, and continuing to alternately perform the step C1) and the step C2) until the temperature of the smoke of the second test sampling hole can reach the preset temperature.

In addition, in the step C), when the flue gas temperature of the first test sampling hole is lower than the preset temperature, the step C3) is performed, a combustion air flow regulating valve of the flue gas furnace arranged on the flue gas furnace is regulated to increase the combustion air flow, the air-coal ratio of the flue gas furnace is adjusted upwards, when the flue gas temperature of the first test sampling hole can reach the preset temperature, the regulation is completed, when the flue gas temperature can not reach the preset temperature, the step C4 is performed, a flue gas flow regulating valve arranged on the flue gas furnace is regulated to increase the gas flow, the flue gas temperature in the flue gas furnace is continuously heated, when the flue gas temperature can reach the preset temperature, the regulation is completed, and when the flue gas temperature can not reach the preset temperature, the step C3) and the step C4) are continuously performed alternately until the flue gas temperature can reach the preset temperature.

Take blast furnace No. 6 of Wu Steel Limited iron works as an example:

when the ratio of the bituminous coal of the No. 6 blast furnace reaches 40%, the coal ratio is only blown to 155kg/t, a third test sampling hole is arranged at the middle-speed grinding outlet, and the smoke temperature of the first test sampling hole, the second test sampling hole and the third test sampling hole is measured by adopting an infrared thermometer for the No. 6 blast furnace, wherein the measurement data are as follows:

table one: flue gas temperature before adjustment

Numbering	Temperature of
		First of all	270℃
Second one	260℃
		Third step	275℃

And after the problems are found, adjusting the air excess coefficient of the 6 blast furnace hot blast stove and the air-coal ratio of the flue gas stove in time to strictly control the flue gas temperature. The air flow of the hot blast stove is reduced to 70018m during measurement³The gas flow is 83511m³H, the air-fuel ratio of the hot blast stove is about 0.75; after measurement, in order to increase the temperature of the waste gas at the inlet of the medium-speed mill, the gas flow regulating valve of the hot blast stove is increased to ensure that the air flow of the hot blast stove is 75110m³The air-fuel ratio is controlled to be about 0.9; the hot blast stove burns more completely, and the temperature of hot blast is improved. Meanwhile, the air flow wave of the flue gas furnace is 2312m³The coal gas flow is 1642m³And h, controlling the air-coal ratio to be about 1.4. The air flow of the flue gas furnace was adjusted to 2516m³And h, controlling the air-coal ratio to be about 1.53, completely burning the coal gas and obviously increasing the temperature of the flue gas.

When the ratio of the bituminous coal of the No. 6 blast furnace reaches 40%, the coal ratio is blown to 170kg/t, and the infrared thermometer is adopted for measuring the flue gas temperature of the first, second and third test sampling holes of the No. 6 blast furnace, wherein the measurement data are as follows:

table one: adjusted middle smoke temperature

In addition, the oxygen content in the waste gas at the inlet of the medium-speed mill before and after adjustment is compared, and the method has the advantages that after the method is used, when the bituminous coal proportion reaches 40%, the coal proportion can be sprayed to 170kg/t, and the oxygen content of the first test sampling hole is basically controlled to be below 5%, so that the burning temperature of a hot blast stove and a flue gas stove is ensured, the waste gas temperature is improved, the moisture of raw coal is further controlled, and the proportion spraying of high-bituminous coal is ensured.