阅读说明：本技术 一种有效延长风口小套使用寿命的方法 (Method for effectively prolonging service life of tuyere small sleeve ) 是由 王子彬 陈得建 王利勇 张凯凯 常中亮 于 2021-08-09 设计创作，主要内容包括：一种有效延长风口小套使用寿命的方法,将铜铬锆粉末置于模具中,通过烧结炉抽真空加热融化粉末,待冷却得到铜铬锆合金风口小套；将风口调整为φ120*470,风口面积扩至0.2151m2；确保风口套进厂产品质量合格；对风口小套进行脱脂处理,然后通过电弧喷涂工艺在其表面喷涂稀土铝；稳定炉内料速、风量及气流的稳定；提高风口小套的冷却强度；与现有技术相比,本发明通过对风口小套材质进行调整、提高风口套进厂验收质量、稳定的气流分布、提高冷却强度办法,能够有效延长风口小套使用寿命,减少工艺休风时间,提高高炉生产指标,直接和间接创造的经济效益可观,全年工艺休风时间得到降低。(A method for effectively prolonging the service life of a tuyere small sleeve comprises the steps of placing copper chromium zirconium powder in a mold, vacuumizing through a sintering furnace, heating and melting the powder, and cooling to obtain the copper chromium zirconium alloy tuyere small sleeve; adjusting the tuyere to phi 120 x 470, and expanding the area of the tuyere to 0.2151m 2; ensuring that the quality of products sleeved into the air inlet is qualified; degreasing the tuyere small sleeve, and then spraying rare earth aluminum on the surface of the tuyere small sleeve by an electric arc spraying process; stabilizing the material speed, air quantity and airflow in the furnace; the cooling strength of the tuyere small sleeve is improved; compared with the prior art, the method has the advantages that the service life of the tuyere small sleeve can be effectively prolonged, the process damping-down time is reduced, the production index of the blast furnace is improved, the directly and indirectly created economic benefit is considerable, and the annual process damping-down time is reduced by adjusting the material of the tuyere small sleeve, improving the quality of the tuyere sleeve which is fed into a factory and is checked, stably distributing air flow and improving the cooling strength.)

1. A method for effectively prolonging the service life of a tuyere small sleeve is characterized by comprising the following steps:

(a) manufacturing the tuyere small sleeve: placing copper chromium zirconium powder in a mould, vacuumizing through a sintering furnace, heating to melt the powder, preserving heat for 30min, and cooling to obtain a copper chromium zirconium alloy tuyere small sleeve;

(b) and (3) tuyere change: adjusting the tuyere to phi 120 x 470, and expanding the area of the tuyere to 0.2151m 2;

(c) quality detection of the tuyere small sleeve: carrying out Y-ray radiographic flaw detection, water pressure experiments and steel ball experiments on the tuyere small sleeve to ensure that the quality of products sleeved into a tuyere factory is qualified;

(d) surface treatment: degreasing the tuyere small sleeve, spraying rare earth aluminum on the surface of the tuyere small sleeve by an electric arc spraying process, and mounting the tuyere small sleeve after the treatment is finished;

(e) stabilizing the material speed, air quantity and airflow in the furnace;

(f) the cooling strength of the tuyere small sleeve is improved: the flow rate of cooling circulating water of the tuyere sleeve is 560m3/h, the water pressure is 1.9MPa, and the water temperature difference is controlled between 5 ℃ and 9 ℃;

the method for effectively prolonging the service life of the tuyere small sleeve as claimed in claim 1, wherein the specific steps of stabilizing the air volume and the air flow in the step (e) are as follows: the method comprises the following steps of pre-screening lump ores before entering a furnace in a raw material yard, reducing powder of the lump ores entering the furnace, improving air permeability in the furnace, and reducing moisture of the lump ores entering the furnace by drying the lump ores below a blast furnace groove by using cold waste heat of a sintering ring; the blast furnace has a wind speed of 270-280 m/s and a blast oxygen enrichment rate of 0.45-0.55%.

2. The method for effectively prolonging the service life of the tuyere small sleeve as recited in claim 2, wherein the concrete steps of stabilizing the material speed in the furnace in the step (e) are as follows: sufficient T iron and T slag are ensured, the alkalinity of the slag is controlled to be 1.15-1.20, the iron tapping time is controlled to be 90-120 min, and the tap slag is discharged in time and completely.

3. The method for effectively prolonging the service life of the tuyere small sleeve as claimed in claim 3, wherein a sieve with a size of 25-60 mm is used in the step (e), and the lump ore is dried at a temperature of 80-100 ℃ after being sieved.

4. The method for effectively prolonging the service life of a tuyere small sleeve as recited in claim 4, wherein the concrete steps of the step (a) are: putting the chromium zirconium powder into a mould, putting the mould into a discharge plasma sintering furnace, vacuumizing the sintering furnace, heating to 600 ℃, preserving heat for 30min, heating to 900 ℃, preserving heat for 5min, and cooling to room temperature after heat preservation.

5. A method of effectively extending the useful life of a tuyere stock as recited in claim 1, wherein: and (f) adopting purified and adjusted weak acid water as cooling circulating water, wherein a main pipe of the circulating water is arranged above the tuyere small sleeve.

Technical Field

The invention belongs to the field of steel making, and particularly relates to a method for effectively prolonging the service life of a tuyere small sleeve.

Background

The length of the online service life of the blast furnace tuyere small sleeve depends on the quality of the tuyere small sleeve and the distribution stability of blast furnace airflow. The front end of the tuyere small sleeve extends into a blast furnace hearth, the working environment is severe, and the tuyere small sleeve not only bears the scouring of hot air at 1200 ℃ and the high-speed abrasion of injected pulverized coal, but also bears the thermal stress generated by the erosion of high-temperature liquid iron slag and the change of the temperature gradient of the inner side and the outer side.

At present, the damage of the tuyere small sleeve is caused by melting loss, ablation points are mostly at the front end of the tuyere sleeve, and the adjustment of blast furnace gas flow distribution is an important factor influencing the online service life of the tuyere sleeve, so that the method for effectively prolonging the service life of the tuyere small sleeve is provided to overcome the existing defects.

Disclosure of Invention

The technical scheme of the invention is as follows; a method for effectively prolonging the service life of a tuyere small sleeve comprises the following steps:

(a) manufacturing the tuyere small sleeve: placing copper chromium zirconium powder in a mould, vacuumizing through a sintering furnace, heating to melt the powder, preserving heat for 30min, and cooling to obtain a copper chromium zirconium alloy tuyere small sleeve;

(b) and (3) tuyere change: adjusting the tuyere to phi 120 x 470, and expanding the area of the tuyere to 0.2151m 2;

(c) quality detection of the tuyere small sleeve: carrying out Y-ray radiographic flaw detection, water pressure experiments and steel ball experiments on the tuyere small sleeve to ensure that the quality of products sleeved into a tuyere factory is qualified;

(d) surface treatment: degreasing the tuyere small sleeve, spraying rare earth aluminum on the surface of the tuyere small sleeve by an electric arc spraying process, and mounting the tuyere small sleeve after the treatment is finished;

(e) stabilizing the material speed, air quantity and airflow in the furnace;

(f) the cooling strength of the tuyere small sleeve is improved: the flow rate of cooling circulating water of the tuyere sleeve is 560m3/h, the water pressure is 1.9MPa, and the water temperature difference is controlled between 5 ℃ and 9 ℃;

preferably, the specific steps of stabilizing the air volume and the air flow in the step (e) are as follows: the method comprises the following steps of pre-screening lump ores before entering a furnace in a raw material yard, reducing powder of the lump ores entering the furnace, improving air permeability in the furnace, and reducing moisture of the lump ores entering the furnace by drying the lump ores below a blast furnace groove by using cold waste heat of a sintering ring; the blast furnace has a wind speed of 270-280 m/s and a blast oxygen enrichment rate of 0.45-0.55%.

Preferably, the specific steps for stabilizing the material speed in the furnace in the step (e) are as follows: sufficient T iron and T slag are ensured, the alkalinity of the slag is controlled to be 1.15-1.20, the iron tapping time is controlled to be 90-120 min, and the tap slag is discharged in time and completely.

Preferably, a sieve with the size of 25-60 mm is used for screening in the step (e), and after screening, the lump ore is dried at the temperature of 80-100 ℃.

Preferably, the specific steps of step (a) are: putting the chromium zirconium powder into a mould, putting the mould into a discharge plasma sintering furnace, vacuumizing the sintering furnace, heating to 600 ℃, preserving heat for 30min, heating to 900 ℃, preserving heat for 5min, and cooling to room temperature after heat preservation.

Preferably, the circulating cooling water in the step (f) is purified and adjusted weak acid water, and a main pipe of the circulating cooling water is arranged above the tuyere small sleeve.

Compared with the prior art, the method has the advantages that the service life of the tuyere small sleeve can be effectively prolonged, the process damping-down time is reduced, the production index of the blast furnace is improved, the directly and indirectly created economic benefit is considerable, and the annual process damping-down time is reduced by adjusting the material of the tuyere small sleeve, improving the quality of the tuyere sleeve which is fed into a factory and is checked, stably distributing air flow and improving the cooling strength.

Detailed Description

The method for effectively prolonging the service life of the tuyere small sleeve can reduce the damping down time of the process and improve the production index of the blast furnace.

The invention firstly changes the manufacture of the tuyere small sleeve, most of the prior tuyere small sleeve adopts a through-flow tuyere sleeve made of all copper, the all copper material has soft structure and low hardness, the size is easy to change at high temperature, the air output of the tuyere is influenced, the tuyere channel is easy to damage, and the stability of the airflow in the furnace is also influenced, therefore, the tuyere small sleeve is manufactured by adopting copper-chromium-zirconium alloy, and the specific manufacturing process is as follows: placing chromium zirconium powder into a mould, placing the mould into a discharge plasma sintering furnace, vacuumizing the sintering furnace, heating to 600 ℃, preserving heat for 30min, heating to 900 ℃, preserving heat for 5min, and cooling to room temperature after finishing the heat preservation to obtain a copper chromium zirconium alloy tuyere small sleeve;

the size layout of the tuyere is improved, the traditional phi 115 x 450 tuyere is adjusted to phi 120 x 470, and the area of the tuyere is expanded from 0.2124m2 to 0.2151m2, so that the blast kinetic energy is adjusted, the edge and central air flow distribution is stabilized, and the coal gas utilization rate is improved;

quality detection is required after the tuyere small sleeve is readjusted, Y-ray radiographic flaw detection, water pressure experiments and steel ball experiments are carried out on the tuyere small sleeve, the quality of products sleeved into a factory by the tuyere is guaranteed to be qualified, meanwhile, the online assembly quality of the tuyere sleeve is improved, the rationality of air inlet is achieved by correcting the tuyere, and the blast furnace damping down caused by air leakage of the tuyere sleeve is prevented;

it is worth noting that the quality inspection system before the tuyere sleeve is put on the line needs to be established in a workshop and random sampling inspection is carried out in each batch when the tuyere sleeve is required to be standardized to enter a factory for inspection and acceptance and improve the process inspection and acceptance.

And after the inspection is finished, the tuyere small sleeve is subjected to degreasing treatment, then rare earth aluminum is sprayed on the surface of the tuyere small sleeve by an electric arc spraying process, the wear resistance and the corrosion resistance of the surface of the tuyere small sleeve are improved, and the tuyere small sleeve is installed after the treatment is finished.

The material speed, the air quantity and the air flow in the blast furnace are required to be ensured to be stable in the production process of the blast furnace;

specifically, the lump ore is pre-screened before entering a furnace in a raw material yard, a screen with the size of 25-60 mm is used for screening, drying treatment is carried out on the lump ore at the temperature of 80-100 ℃ after screening, powder of the lump ore entering the furnace is reduced, the air permeability in the furnace is improved, and meanwhile, the lump ore below a blast furnace groove is dried by using the cold waste heat of a sintering ring, so that the moisture of the lump ore entering the furnace is reduced; the air speed of the blast furnace is 270-280 m/s, the oxygen enrichment rate of blast air is 0.45-0.55%, and the large fluctuation of the air temperature during the furnace change of the hot blast furnace is avoided;

sufficient T iron and T slag are ensured, the alkalinity of slag is controlled to be 1.15-1.20, the iron slag discharging time is controlled to be 90-120 min, and the slag is discharged completely in time.

In the production process, the tuyere small sleeve is cooled very well, the cooling strength of the tuyere small sleeve needs to be improved, the cooling circulating water flow of the tuyere sleeve is 560m3/h, the water pressure is 1.9MPa, and the water temperature difference is controlled between 5 ℃ and 9 ℃.

The cooling circulating water is purified and adjusted weak acid water, the amount of dirt can be reduced by adopting the weak acid water, the circulating water pipe is prevented from being blocked by the dirt, and a corrosion inhibitor can be added into the cooling water to prevent the cooling water from corroding the water pipe; the main pipe of the circulating water is arranged above the tuyere small sleeve, and when water is cut off, residual water can also continuously pass through the tuyere small sleeve under the action of gravity, so that the tuyere small sleeve is prevented from being damaged when the temperature of the tuyere small sleeve is not lowered in time;

a reasonable cooling system is selected, and sufficient cooling water flow and water pressure are the basis for ensuring the cooling effect of the tuyere sleeve and are favorable conditions for stabilizing slag crust and ensuring the smooth operation of a furnace.

The invention has been described in an illustrative manner, and it is to be understood that the invention is not limited to the precise form disclosed, and that various insubstantial modifications of the inventive concepts and solutions, or their direct application to other applications without such modifications, are intended to be covered by the scope of the invention.