Constant-flow non-disturbance furnace changing system for blast furnace hot blast stove

Abstract

The utility model relates to a constant-flow non-disturbance furnace changing system for a blast furnace hot blast stove. The system comprises a compressed air main pipeline, a cold air main pipeline, an air supply pipeline, a branch stamping pipeline and a branch cold air pipeline, according to the constant-flow non-disturbance furnace changing system for the blast furnace hot blast stove, cold air pressurizing and compressed air pressurizing of the air feeder II are connected in parallel and are mutually standby systems, so that normal furnace changing and running of the hot blast stove when any pressurizing system breaks down are guaranteed; besides, compressed air is obtained by arranging an independent air compressor, so that the compressed air is independent of a compressed air conveying system in the steel mill, and two or more air storage tanks are arranged to ensure the pressure of the compressed air at the output end and play roles in stabilizing pressure and buffering, so that pressure fluctuation in a compressed air main pipeline in the steel mill can be thoroughly avoided, and the service life of the steel mill is prolonged. And safe gas use of other production departments is guaranteed, meanwhile, potential safety hazards caused by frequent fluctuation of pressure in the compressed air pipeline are reduced, and practicability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of blast furnace ironmaking equipment, in particular to a blast furnace hot blast furnace constant flow disturbance-free furnace replacement system. Background Art

[0002] In the blast furnace production process, the main task of the hot blast stove is to heat the cold air blown by the blower to above 1200℃, and then send the hot air to the blast furnace. A blast furnace is usually equipped with three or four hot blast stoves, which use the "two burning and one sending" or "two burning and two sending" mode to transport and supply air to the blast furnace. When the hot blast stove is replaced, it is first necessary to pressurize the hot blast stove to be supplied with air, so that the pressure on both sides of the hot blast stove tends to be balanced, reduce the fluctuations in air volume and pressure caused by the furnace change, and maintain the stability and smooth operation of the blast furnace. When the furnace is changed with a fixed air volume pressurization, part of the air volume needs to be allocated to the pressurized hot blast stove, resulting in a decrease in the amount of air entering the furnace and a decrease in the pressure inside the furnace, which can easily cause potential safety accidents such as an increase in the pressure difference inside the blast furnace, local suspended or slippery materials, splashing of molten iron, and incomplete iron discharge. The current mainstream fan constant pressure blast furnace changing mode can significantly reduce the fluctuation of air volume and air pressure (less than 5kPa), but there is also a lag in the adjustment of air pressure and air volume, and the fan power is frequently automatically adjusted during the pressurization process, which is easy to increase the equipment failure rate. In order to solve the above problems, the use of independent compressed air instead of cold air to pressurize the hot blast furnace has attracted the attention of steel companies. This method can achieve disturbance-free furnace change and constant flow blasting of the hot blast furnace. This method no longer uses the blower cold air for pressurization, but uses the compressed air in the company's internal compressed air pipeline for pressure equalization operation, which can reduce the pressurization consumption of cold air, give full play to the capacity of the blower, and increase the output of the blast furnace. At the same time, it can also reduce the fluctuation of the air supply pressure caused by pressurization, solving the problem of mutual constraints between the hot blast furnace change and the stable production of the blast furnace. In addition, the automation level of the furnace changing process has been improved, which has accelerated the furnace changing speed without changing the infrastructure, reduced the furnace changing time, and achieved precise control of the pressurization process, avoiding the impact of each furnace changing on the fluctuation of wind pressure and air volume, ensuring that the blast furnace air supply is not affected, which is conducive to the smooth operation of the blast furnace and stable and high production. It is an important measure to achieve intelligent production of blast furnace ironmaking. Although the above-mentioned significant effects have been achieved by using compressed air in the main pipeline within the enterprise to equalize the pressure of the hot blast furnace, it will also cause increased pressure fluctuations in the compressed air main pipeline. In particular, when pressurizing multiple hot blast furnaces at the same time, the instability of the compressed air pressure in the pipeline is likely to bring potential safety hazards to other production departments of the enterprise that use compressed air;

[0003] Therefore, in order to overcome the shortcomings of the existing pipeline compressed air furnace changing technology, it is necessary to find a more stable furnace changing system to truly achieve zero-disturbance furnace changing of hot blast furnaces and safe and stable production of enterprises. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a novel furnace changing system, which not only realizes zero-disturbance furnace changing of hot blast furnaces and constant-flow blasting of blast furnaces, but also can avoid the pressure fluctuation of compressed air in the main pipeline of the enterprise, thereby affecting the normal operation of other links.

[0005] The technical problem to be solved by the utility model is achieved through the following technical solution. The system includes a compressed air main line, a cold air main line, an air supply line, a branch stamping line and a branch cold air line, wherein the branch stamping line and the branch cold air line are connected in parallel to the air supply line;

[0006] The compressed air main line is configured to press the hot blast furnace, and an air compressor, a plurality of air storage tanks and a compressed air main line valve group are arranged on it in sequence according to the air flow direction;

[0007] The cold air main line is configured to supply air to the hot air furnace, and is provided with a blower I and a cold air main line valve group according to the airflow direction;

[0008] The air outlet end of the air supply pipeline is connected to the air inlet of the hot air furnace, and the air supply pipeline is connected to the main cold air pipeline;

[0009] The branch cold air pipeline is provided with a blower II and a branch cold air pipeline equalizing pressure valve group in sequence according to the airflow direction;

[0010] The air inlet end of the branch stamping pipeline is connected to the main compressed air pipeline, and branch stamping pipeline equalizing pressure valve groups are arranged thereon in sequence according to the air flow direction.

[0011] Preferably, the compressed air main line valve group comprises an air source valve, a cut-off valve I and a cut-off valve II which are sequentially arranged according to the air flow direction;

[0012] The air source valve is installed on the compressed air main line between the air compressor and the air outlet pipe;

[0013] The cut-off valve I is installed at the rear of the gas storage tank;

[0014] The air inlet end of the branch stamping pipeline is connected to the compressed air main pipeline between the cut-off valve I and the cut-off valve II.

[0015] Preferably, the cold air main line valve group includes a cut-off valve III, a cold air valve is installed on the pipeline connected between the cold air main line and the air supply line, and the air inlet end of the pipeline is located on the cold air main line between the air supply fan I and the cut-off valve III.

[0016] Preferably, the branch cold air pipeline pressure equalizing valve group and the branch stamping pipeline pressure equalizing valve group both include a manual pressure equalizing valve and an automatic pressure equalizing valve, and a cut-off valve IV is also provided at the air inlet end of the branch stamping pipeline.

[0017] Preferably, the compressed air main pipeline and the air supply pipeline are both provided with a pressure gauge, a flow meter and a temperature gauge.

[0018] Preferably, at least two gas storage tanks are provided.

[0019] Preferably, a pressure alarm system is installed on the gas storage tank.

[0020] Preferably, the air supply fan I and the air supply fan II are both blowers.

[0021] Preferably, the branch stamping pipeline and the branch cold air pipeline are connected in parallel to the air supply pipeline through a three-way valve.

[0022] Compared with the prior art, the beneficial technical effects of the utility model are:

[0023] (1) The cold air charging and compressed air charging of the blower II of the constant flow disturbance-free furnace changing system of the blast furnace hot blast stove exist in parallel and serve as backup systems for each other, ensuring the normal furnace changing and operation of the hot blast stove when any of the charging systems fails; in addition, by setting up a separate air compressor to obtain compressed air, it is independent of the compressed air transmission system inside the steel plant, and two or more air storage tanks are set to ensure the compressed air pressure at the output end, which plays a role in stabilizing and buffering. This can completely avoid the pressure fluctuation in the compressed air main pipeline inside the steel plant, ensure the safe use of gas in other production departments, and reduce the potential safety hazards caused by the frequent pressure fluctuations in the compressed air pipeline, which is highly practical;

[0024] (2) The hot blast furnace can be pressurized by independent compressed air and fan II, avoiding the diversion of cold air blown by fan I and frequent power changes, ensuring constant flow of air for other hot blast furnaces in operation, reducing the risk of air volume and pressure fluctuations and fan failure, and ultimately facilitating the stable and smooth operation of the blast furnace. Its structural design is reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of the installation of the utility model.

[0026] In the figure: 1. Compressed air main line; 2. Cold air main line; 3. Air supply line; 4. Branch stamping line; 5. Branch cold air line; 6. Hot air furnace; 7. Air compressor; 8. Air storage tank; 9. Air source valve; 10. Shut-off valve I; 11. Shut-off valve II; 12. Pressure alarm system; 13. Shut-off valve III; 14. Cold air valve; 15. Supply fan I; 16. Supply fan II; 17. Branch stamping line equalizing valve group; 18. Branch cold air line equalizing valve group; 19. Shut-off valve IV; 20. Three-way valve. DETAILED DESCRIPTION

[0027] The specific technical solutions of the present invention are further described below with reference to the accompanying drawings, so as to facilitate further understanding of the present invention by those skilled in the art, and do not constitute any limitation to the rights thereof.

[0028] Example 1, reference Figure 1 A constant flow disturbance-free furnace replacement system for a blast furnace hot blast furnace, the system comprises a compressed air main line 1, a cold air main line 2, an air supply line 3, a branch stamping line 4 and a branch cold air line 5, wherein the branch stamping line 4 and the branch cold air line 5 are connected in parallel to the air supply line 3 through a three-way valve;

[0029] The compressed air main line 1 is configured to punch the hot blast furnace 6, and an air compressor 7, a plurality of gas storage tanks 8 and a compressed air main line valve group are arranged thereon in sequence according to the airflow direction. The compressed air main line valve group includes an air source valve 9, a cut-off valve I 10 and a cut-off valve II 11 arranged in sequence according to the airflow direction. At least two gas storage tanks 8 are provided. The gas storage tank 8 can be equipped with a pressure alarm system 12 to monitor the pressure change in the tank in real time. When the pressure in the tank is lower than the specified value during pressurization, an alarm will be automatically sounded, and the air compressor 7 is configured to supplement the compressed gas in the gas storage tank 8;

[0030] In addition, the compressed air main line 1 can simultaneously pressurize a single or multiple hot air furnaces 6, and the pressure gauge, flow meter and temperature meter on the compressed air main line 1 can perform real-time detection;

[0031] The air source valve 9 is installed on the compressed air main line 1 between the air compressor 7 and the air outlet pipe; the cut-off valve I10 is installed at the rear of the air storage tank 8; the air inlet end of the branch stamping pipeline 4 is connected to the compressed air main line 1 between the cut-off valve I10 and the cut-off valve II11;

[0032] The cold air main line 2 is configured to supply air to the hot air furnace 6, and is provided with a blower I 15 and a cold air main line valve group according to the air flow direction. The cold air main line valve group includes a cut-off valve III 13, and a cold air valve 14 is installed on the pipeline connected between the cold air main line 2 and the air supply pipeline 3, and the air inlet end of the pipeline is located on the cold air main line 2 between the blower I 15 and the cut-off valve III 13. The blowers I 15 and II 16 are both blowers;

[0033] The air outlet end of the air supply pipeline 3 is connected to the air inlet of the hot air furnace 6, and the air supply pipeline 3 is connected to the cold air main pipeline 2;

[0034] The branch cold air pipeline 5 is provided with a blower II 16 and a branch cold air pipeline equalizing pressure valve group 18 in sequence according to the airflow direction;

[0035] It should be noted that the branch cold air pipeline 5 is independently connected with a blower II 16, through which the hot blast furnace 6 can be pressurized, so that the problem of air volume partial pressure fluctuation caused by the blower I 15 pressurization can be avoided. In other words, the system can be pressurized by cold air and compressed air, which complement each other and serve as a backup for each other, and can fully ensure that the hot air volume and air pressure blown into the hot blast furnace 6 do not fluctuate while the hot blast furnace 6 is operated under equal pressure;

[0036] The air inlet end of the branch stamping pipeline 4 is connected to the compressed air main pipeline 1, and a branch stamping pipeline equalizing valve group 17 is arranged thereon in sequence according to the air flow direction. The branch cold air pipeline equalizing valve group 18 and the branch stamping pipeline equalizing valve group 17 both include a manual equalizing valve and an automatic equalizing valve. The factory staff can choose the automatic equalizing valve for pressure equalization or the manual equalizing valve for pressure equalization, which has strong selectivity. A cut-off valve IV19 is also arranged at the air inlet end of the branch stamping pipeline 4;

[0037] The compressed air main line 1 and the air supply line 3 are both provided with a pressure gauge, a flow meter and a temperature gauge.

[0038] The operating principle of the hot blast furnace constant flow disturbance-free furnace changing system is:

[0039] (1) When the air blower II 16 is used for cold air pressure charging, the cold air valve 14 is not opened, and the automatic pressure equalizing valve or the manual pressure equalizing valve on the branch cold air pipeline 15 is opened, and the cold air enters the hot air furnace 6 through the air supply pipeline 3 to complete the pressure equalization operation. After the pressure equalization is completed, the cold air valve 14 is opened to enter the normal air supply step;

[0040] (2) When the independent compressed air system is used for charging, the cold air valve 14 is also not opened to ensure that the air volume and air pressure in the cold air main line 2 do not change, so as to achieve constant flow of air for other hot blast furnaces 6 and blast furnaces and ensure the stability of air volume and air pressure. At this time, the compressed air enters the compressed air storage tank 8 through the air source valve 9, and then the shut-off valve I10 connected to the air storage tank 8 is opened to allow the compressed air to enter the compressed air main line 1;

[0041] When only one hot blast furnace 6 is pressurized, the shut-off valve II 11 is closed, and the shut-off valve IV 19 is opened to allow the compressed air to enter the branch stamping pipeline 4, and then the branch stamping pipeline equalizing valve group 17 on the branch stamping pipeline 4 can be used for pressurization. Either a manual equalizing valve or an automatic equalizing valve can be selected. At this time, the compressed air enters the air supply pipeline 3 through the three-way valve 20. The pressure gauge, flow meter and temperature gauge on the air supply pipeline 3 can detect the gas pressure, flow rate and temperature changes in the air supply pipeline 3 in real time. When the pressurization is completed, the gas source valve 9 and the branch stamping pipeline equalizing valve group 17 on the branch stamping pipeline 4 are closed to stop the compressed air supply, and then the cold air valve 14 is opened to put the hot blast furnace 6 into the air supply state;

[0042] When two or more hot blast furnaces 6 are pressurized at the same time, the shut-off valve II 11 is opened to allow the compressed air to flow to the other hot blast furnaces 6 .

[0043] The cold air pressurization and compressed air pressurization of the blower II 16 of the constant flow disturbance-free furnace changing system of the blast furnace hot blast stove exist in parallel and serve as backup systems for each other, ensuring the normal furnace changing and operation of the hot blast stove 6 when any of the pressurizing systems fails; in addition, compressed air is obtained by setting up a separate air compressor 7, making it independent of the compressed air transmission system inside the steel plant, and two or more air storage tanks 8 are set to ensure the compressed air pressure at the output end, which plays a role in stabilizing and buffering. This can completely avoid pressure fluctuations in the compressed air main pipeline inside the steel plant, ensure safe gas use in other production departments, and at the same time reduce potential safety hazards caused by frequent pressure fluctuations in the compressed air pipeline, and has strong practicality.

Claims

1. A constant flow disturbance-free furnace replacement system for hot blast furnaces of blast furnaces, characterized in that: The system comprises a compressed air main line, a cold air main line, an air supply line, a branch stamping line and a branch cold air line, wherein the branch stamping line and the branch cold air line are connected in parallel to the air supply line; The compressed air main line is configured to press the hot blast furnace, and an air compressor, a plurality of air storage tanks and a compressed air main line valve group are arranged on it in sequence according to the air flow direction; The cold air main line is configured to supply air to the hot air furnace, and is provided with a blower I and a cold air main line valve group according to the airflow direction; The air outlet end of the air supply pipeline is connected to the air inlet of the hot air furnace, and the air supply pipeline is connected to the main cold air pipeline; The branch cold air pipeline is provided with a blower II and a branch cold air pipeline equalizing pressure valve group in sequence according to the airflow direction; The air inlet end of the branch stamping pipeline is connected to the main compressed air pipeline, and branch stamping pipeline equalizing pressure valve groups are arranged thereon in sequence according to the air flow direction.

2. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The compressed air main line valve group includes an air source valve, a cut-off valve I and a cut-off valve II which are arranged in sequence according to the air flow direction; The air source valve is installed on the compressed air main line between the air compressor and the air outlet pipe; The cut-off valve I is installed at the rear of the gas storage tank; The air inlet end of the branch stamping pipeline is connected to the compressed air main pipeline between the cut-off valve I and the cut-off valve II.

3. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The cold air main line valve group includes a cut-off valve III, a cold air valve is installed on the pipeline connected between the cold air main line and the air supply pipeline, and the air inlet end of the pipeline is located on the cold air main line between the air supply fan I and the cut-off valve III.

4. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The branch cold air pipeline pressure equalizing valve group and the branch stamping pipeline pressure equalizing valve group both include a manual pressure equalizing valve and an automatic pressure equalizing valve, and a cut-off valve IV is also provided at the air inlet end of the branch stamping pipeline.

5. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The compressed air main pipeline and the air supply pipeline are both provided with a pressure gauge, a flow meter and a temperature gauge.

6. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: At least two gas storage tanks are provided.

7. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The air blower I and the air blower II are both blowers.

8. A constant flow disturbance-free furnace replacement system for hot blast stoves of blast furnace according to claim 1, characterized in that: The branch stamping pipeline and the branch cold air pipeline are connected in parallel to the air supply pipeline through a three-way valve.

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