Blast furnace top charging bucket pressure equalizing treatment method

Abstract

The invention discloses a pressure equalizing treatment method for a blast furnace top charging bucket, which adopts inert waste gas to perform pressure equalizing treatment on the furnace top charging bucket, and the inert waste gas comes from inert gas generated by a blast furnace ironmaking system. According to the treatment method, the inert waste gas is adopted to replace blast furnace semi-clean gas, so that the discharge amount of the gas can be reduced, the energy is saved, a charging bucket gas recovery link is canceled, and the gas can be directly discharged to the atmosphere after material distribution is finished; meanwhile, the dust content in exhausted gas can be obviously reduced; and finally, the equipment involved in the treatment method is simple in structure and simple and convenient to operate, and compared with the existing two-stage recovery process depending on cloth bags and injection, the investment cost is low, and the phenomenon that the semi-clean gas is not completely recovered can be fundamentally solved.

Description

Technical Field

[0001] The invention relates to the technical field of blast furnace ironmaking, and in particular to a method for pressure equalization treatment of a blast furnace top material tank. Background Art

[0002] In the prior art, the process flow of charging on the top of a blast furnace is as follows: two material tanks are arranged on the top of the furnace, one of the material tanks is loaded with material first, and after receiving the material, the upper seal valve is closed and the pressure is equalized, and after receiving the material discharge instruction, the lower seal valve is opened for charging, and after completion, the lower seal valve is closed and the pressure is released, and after completion, it is ready to receive the next feed, and the two material tanks are alternately cycled back and forth to complete the blast furnace charging work.

[0003] The blast furnace top material tank generally uses blast furnace semi-clean gas for pressure equalization, and directly discharges it into the atmosphere after the material is distributed. This not only wastes gas, but also causes dust emissions in the gas to pollute the airspace. Preliminary estimates show that a 2500m 3 Blast furnace, with an annual output of 2.2 million tons, emits approximately 18.5 million Nm3 of coal gas per year 3 , emitting approximately 93 tons of dust.

[0004] At present, some blast furnaces have been transformed into ultra-low emission furnaces, and the two-stage recovery of coal gas from the furnace top tank is adopted. First, it is recovered by bag, and then after the pressure drops to about 50Kpa, it is recovered by injection. This method has a large investment, complex pipe network, cumbersome operation, and incomplete recovery. In addition, the investment is large, and a 2500m 3 A blast furnace requires an investment of approximately 6 million yuan and takes more than 8 years to recover the investment. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a method for pressure equalization treatment of a blast furnace top material tank, so as to solve the problems in the prior art of using blast furnace semi-clean gas for pressure equalization, such as waste of gas, difficulty in recovery and treatment, and high cost.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for equalizing the pressure of a blast furnace top tank comprises the following steps: using inerting waste gas to equalize the pressure of the top tank, wherein the inerting waste gas comes from inerting gas generated by a blast furnace ironmaking system.

[0008] Preferably, the temperature of the inert gas is ≤200°C; the oxygen content of the inert gas is ≤4% by mass, and the N2+CO2 content of the inert gas is ≥95%; the particulate matter content of the inert gas is ≤10mg / m 3 .

[0009] Preferably, the processing method is implemented by the following equipment:

[0010] It comprises an inert gas storage tank, inert gas generated in the blast furnace ironmaking system is connected to the air flow at the air inlet end of the compressor, the air outlet end of the compressor is connected to the air flow at the air inlet end of the heat exchanger, and the air outlet end of the heat exchanger is connected to the air flow of the inert gas storage tank; the inert gas storage tank is connected to the blast furnace top material tank pipeline.

[0011] Preferably, before charging the blast furnace, the inert gas in the inert gas storage tank is delivered into the material tank by a compressor for pressure equalization.

[0012] Preferably, the temperature of the inert gas is adjusted before entering the inert gas storage tank so that the temperature of the inert gas does not exceed 200°C.

[0013] Preferably, during the material distribution process, the inert gas storage tank continuously supplies gas to the blast furnace top material tank, and the intelligent expert system is used to control the compressor so that the pressure in the blast furnace top material tank is always greater than the blast furnace top pressure by 5kpa±; after the material distribution is completed, the inert gas in the blast furnace top material tank can be directly discharged into the atmosphere.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The treatment method described in the present invention adopts inerted waste gas instead of blast furnace semi-clean coal gas, which can not only reduce the emission of coal gas and save energy, but also eliminate the gas recovery link in the material tank, and can be directly discharged into the atmosphere after the material distribution is completed; at the same time, it can significantly reduce the dust content in the exhaust gas; finally, the equipment involved in the treatment method described in the present invention has a simple structure and is easy to operate. Compared with the current two-stage recovery process of bag filter and injection, it has a low investment cost and can fundamentally solve the problem of incomplete recovery of semi-clean coal gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a diagram of the device involved in the processing method of the present invention.

[0017] In the figure: 1 is a compressor, 2 is a one-way valve, 3 is a heat exchanger, 4 is an inert gas storage tank, 5 is a pneumatic valve, and 6 is a blast furnace top material tank. DETAILED DESCRIPTION

[0018] The present invention will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the present invention belong to the scope of protection of the present invention.

[0019] Unless otherwise indicated in specific cases in the present invention, the numerical ranges listed herein include the upper and lower limits, and all integers and fractions within the range, and are not limited to the specific values ​​listed when defining the range.

[0020] 1. A method for equalizing the pressure of a blast furnace top tank

[0021] The furnace top material tank is pressure-equalized by using inerting waste gas, and the inerting waste gas comes from the inerting gas generated by the blast furnace ironmaking system.

[0022] In some embodiments, the temperature of the inert gas is ≤200°C; the oxygen content of the inert gas is ≤4% by mass, and the N2+CO2 content of the inert gas is ≥95%; the particulate matter content of the inert gas is ≤10 mg / m 3 . Control the temperature of the inert gas to avoid damage to the equipment caused by excessive temperature, shorten its service life, improve safety, and reduce energy consumption; but too low temperature will affect the fluidity and diffusivity of the inert gas, affect the pressure equalization effect, and low temperature may also cause steam in the water to condense and form condensed water, affecting the raw material reaction of the furnace. Therefore, the temperature of the inert gas is controlled between 140 and 200 ° C. Control the oxygen content in the inert gas to reduce the risk of detonation, so the oxygen content of the inert gas is ≤4%.

[0023] In some embodiments, the processing method is implemented by the following equipment: Figure 1 As shown, it includes an inert gas storage tank. The inert gas generated in the blast furnace ironmaking system is transported to the inert gas storage tank through a pipeline, and then transported to the blast furnace top tank through a pipeline for pressure equalization. The inert gas is temperature-adjusted before entering the inert gas storage tank so that the temperature of the inert gas does not exceed 200°C. During the material distribution process, the inert gas storage tank continuously supplies gas to the blast furnace top tank, so that the pressure in the blast furnace top tank is greater than the blast furnace top pressure; after the material distribution is completed, the inert gas in the blast furnace top tank can be directly discharged into the atmosphere.

[0024] 2. Embodiment

[0025] Take a blast furnace ironmaking plant as an example. The 2# blast furnace of the plant has a blast furnace volume of 1350m 3 , the gas pressure at the top of the furnace is 2kg / cm 2 , tank capacity 38m 3 , 160 batches of materials are loaded every day, an average of 6.7 batches of materials are loaded every hour, and 3,300 tons of iron are produced throughout the day. The treatment method described in this application is used to treat it, such as Figure 1 As shown in the figure, the dotted line is the direction of inert gas entering. The inert gas generated by the blast furnace ironmaking system enters the compressor 1 through the pipeline. The compressor 1 compresses the inert gas and then transports it to the heat exchanger 3. The temperature of the inert gas is controlled by the heat exchanger 3 so that it can be stabilized at no more than 200°C. Then the inert gas is transported to the inert gas storage tank 4 through the pipeline. Finally, the inert gas storage tank 4 (100m 3) is transported to the blast furnace top tank 6 through a pipeline. Before the blast furnace is laid, the inert gas in the inert gas storage tank is sent into the tank by a compressor for pressure equalization. During the laying process, the inert gas storage tank continuously supplies gas to the blast furnace top tank, and the compressor is controlled by an intelligent expert system so that the pressure in the blast furnace top tank is always greater than the blast furnace top pressure 5kpa±; after the laying is completed, the inert gas in the blast furnace top tank can be directly discharged into the atmosphere.

[0026] The following effects were achieved after the method described in this application was used for treatment:

[0027] 1. The volume of the gas storage tank is 3.12 times that of the material tank. Before the material tank is filled with materials and the pressure is equalized, it is necessary to appropriately increase the pressure of the gas storage tank to ensure that the pressure equalization and gas filling time is consistent with the original process (6 to 10 seconds) and to increase it to 0.3 to 0.5 kg / cm higher than the furnace top pressure. 2 That's it.

[0028] 2. During the material distribution process, the compressor speed is automatically adjusted according to the pressure changes in the material tank, and the material tank pressure can be accurately controlled to always be higher than the furnace top pressure. The entire material distribution is not affected and the material discharge is smooth.

[0029] 3. After unloading, the gas pressure in the discharge tank is released. It can be seen with the naked eye that the dust content in the exhaust gas is significantly reduced, indicating that the dust reduction effect is obvious. At the same time, the exhaust gas is tested and can meet the emission standards.

[0030] 4. During the entire experimental process, the valve opened and closed smoothly without any jamming, and the feeding work remained normal.

[0031] 5. 160 batches of materials per day, using inert waste gas instead of semi-clean gas, can reduce gas emissions by 24,000 m3 per day 3 , with an economic value of approximately 3,600 yuan.

[0032] Compared with the two-stage recovery process of bag filter and ejector in the prior art, the treatment process described in the present application can fundamentally solve the problem of incomplete recovery of semi-clean coal gas. In the prior art, whether it is a bag filter or a two-stage recovery process of ejector, it is not only necessary to configure bag dust collectors, ejectors and other devices, but also the operation process is complicated, and it is necessary to control the start and shutdown of the bag dust collector and the adjustment of the ejector in time. The operators need a high level of skills and the training cost is high. At the same time, the use efficiency of these equipment is affected by many factors, such as bag blockage, ejector failure, etc., which will lead to unstable quality of recovered coal gas, thereby affecting its subsequent treatment process. However, the treatment method described in the present application fundamentally does not require the installation of equipment such as cloth bags and ejectors. It only needs to install an inert gas storage tank and some pipelines. Moreover, the treatment process of the method described in the present application is simple. The intelligent expert system is used to control the compressor so that the pressure in the blast furnace top material tank is always greater than the blast furnace top pressure by 5kpa±; after the material distribution is completed, the inert gas in the blast furnace top material tank can be directly discharged into the atmosphere. In this process, the temperature, oxygen content and particulate matter content of the inert gas are controllable, which ensures the stability and reliability of the pressure equalization treatment. There is no need for complicated recovery and processing links, which reduces the uncertainty of the process.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for equalizing the pressure of a blast furnace top tank, characterized in that: The furnace top material tank is pressure-equalized by using inerting waste gas, and the inerting waste gas comes from the inerting gas generated by the blast furnace ironmaking system.

2. The processing method according to claim 1, characterized in that: The temperature of the inert gas is ≤200°C; the oxygen content of the inert gas is ≤4% by mass percentage, and the N2+CO2 content of the inert gas is ≥95%; the particulate matter content of the inert gas is ≤10mg / m 3 .

3. The processing method according to claim 1, characterized in that: The processing method is implemented by the following equipment: The invention comprises an inert gas storage tank (4), wherein the inert gas generated in the blast furnace ironmaking system is connected to the air flow of the air inlet end of the compressor (1), the air outlet end of the compressor (1) is connected to the air flow of the air inlet end of the heat exchanger (3), and the air outlet end of the heat exchanger is connected to the air flow of the inert gas storage tank; the inert gas storage tank is connected to the blast furnace top material tank via a pipeline.

4. The processing method according to claim 3, characterized in that: Before charging the blast furnace, the inert gas in the inert gas storage tank is sent into the charging tank through a compressor for pressure equalization.

5. The processing method according to claim 3, characterized in that: The temperature of the inert gas is adjusted before entering the inert gas storage tank so that the temperature of the inert gas does not exceed 200°C.

6. The processing method according to claim 3, characterized in that: During the material distribution process, the inert gas is continuously supplied from the gas storage tank to the blast furnace top tank through the compressor, so that the pressure in the blast furnace top tank is greater than the blast furnace top gas pressure; after the material distribution is completed, the inert gas in the blast furnace top tank can be directly discharged into the atmosphere.

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