A method for increasing converter gas recovery

Abstract

The present invention belongs to the field of metallurgical technology, and specifically relates to a method for increasing the recovery of converter gas. During the normal operation of the gas holder, a chain condition for the converter blowing time is set, and the chain condition includes a recovery and release condition for converter blowing ≤5min and a recovery and release condition after converter blowing for 5min; the recovery and release condition for converter blowing ≤5min is: after the converter starts blowing, the re-blowing system starts timing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, the gas recovery system sends out a recovery message, and the gas starts to be recovered; when the O2 content is >1wt%, the system switches to a release state. Compared with traditional gas recovery chain conditions, the system of the present invention is safer, the gas recovery time is increased by 90-120 seconds / furnace, and the gas recovery volume is increased by about 15m 3 / t, which increases the gas recovery volume, saves energy consumption indicators, and reduces carbon emissions, and has a high promotion value for domestic steel mills.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for increasing the recovery amount of converter gas. Background Art

[0002] The recovery of converter gas in domestic steel plants is generally carried out automatically with the CO and O2 content in the flue gas as the process interlocking conditions for recovery and release. The converter gas magnetic oxygen analyzer is installed in the outlet pipe of the primary dust removal fan, and the gas is continuously pumped for detection during the converter blowing. When the analyzer detects that the CO and O2 content in the flue gas meets the recovery conditions, the water seal check valve and the three-way valve are opened to the recovery position in turn, and the converter gas begins to be recovered. If the recovery conditions are not met, the three-way valve and the water seal check valve are closed in turn, and the system is switched to the release state. The recovery interlocking conditions are all taken from a single system, and are interlocking conditions with high first and low later, otherwise the program cannot make a correct judgment.

[0003] When the traditional gas recovery converter blowing time is about 2 minutes to 2 and a half minutes, the O2 content in the gas is ≤1%, which meets the safety conditions. At this time, the CO content in the gas is generally around 10-20%. Considering the 15-second opening time of the three-way valve and the 60-second travel distance from the start point of the converter flue to the detection point of the magnetic oxygen analyzer, the CO content reaches more than 25% after 75 seconds and meets the conditions for recovery. Since the pipeline from the converter flue to the magnetic oxygen analyzer is long, there is a time difference. There is also a time difference from the detection data meeting the gas recovery conditions to the water seal check valve and the three-way valve opening. Due to the time difference in these two aspects, the converter gas that has recovery value cannot be recovered, resulting in unnecessary energy waste. Summary of the invention

[0004] The purpose of the present invention is to provide a method for increasing the recovery of converter gas. By formulating the chain conditions of CO content and O2 content, and then combining the magnetic oxygen analysis data of the gas to comprehensively judge the timing of gas recovery, the gas with recovery value in the early stage of converter blowing can be fully recovered, the recovery of converter gas can be greatly increased, carbon emissions can be reduced, and energy waste can be reduced. The method has a high promotion value for domestic steel mills.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A method for increasing the recovery of converter gas, wherein during the normal operation of the gas holder, a chain condition of converter blowing time is set, wherein the chain condition includes a recovery and release condition of converter blowing ≤ 5 minutes and a recovery and release condition after converter blowing for 5 minutes;

[0007] The recovery and release conditions for the converter blowing ≤5min are: after the converter starts blowing, the re-blowing system starts timing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, the gas recovery system sends out a recovery message, and the gas starts to be recovered; when the O2 content is >1wt%, the system switches to a release state.

[0008] The present invention does not detect the emission condition of 21wt% within 5 minutes of converter blowing. At this time, only O2>1wt% is used as the emission condition, which not only ensures the safety issues during gas recovery and emission, but also can recover more gas.

[0009] In the above technical scheme, further, the recovery and release conditions after the converter is blown for 5 minutes are: after the converter is blown for 5 minutes, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, and the CO content is ≥25wt%, and the gas begins to be recovered; when the O2 content is >1wt%, the system is switched to the release state.

[0010] In the above technical scheme, further, the recovery and release conditions after the converter is blown for 5 minutes are: after the converter is blown for 5 minutes, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, and the CO content is ≥25wt%, and the gas begins to be recovered; when the CO content is <21wt%, the system is switched to the release state.

[0011] In the above technical scheme, further, the method also includes a medium calorific value recovery mode; the medium calorific value recovery mode is: when the gas tank is in the middle tank position, after the converter starts blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥25%, and the gas begins to be recovered. When the CO content is <21%, the system switches to the release state.

[0012] In the above technical scheme, further, the medium calorific value recovery mode is: when the gas tank is in the middle tank position, after the converter starts blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥25%, and the gas begins to be recovered. When the O2 content is >1%, the system switches to the release state.

[0013] In the above technical scheme, further, the method also includes a high calorific value recovery mode; the high calorific value recovery mode is: when the gas tank is at a high tank level, after the converter starts blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥29%, and the gas begins to be recovered. When the CO content is <25%, the system switches to a release state.

[0014] In the above technical scheme, further, the high calorific value recovery mode is: when the gas tank is at a high tank level, after the converter starts blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥29%, and the gas begins to be recovered. When the O2 content is >1%, the system switches to a release state.

[0015] In the above technical solution, further, the gas recovery system sends out recovery information, and the three-way valve opening time is 10-15s.

[0016] In the above technical solution, further, the gas recovery system sends out a release information, and the closing time of the three-way valve is 10-15s.

[0017] The beneficial effects of the present invention are:

[0018] 1. The traditional gas recovery condition is that the CO content is greater than or equal to 25%. At the same time, the CO content changes very quickly, quickly reaching about 40-50%, and the action time of the three-way valve is about 15 seconds, resulting in a lot of waste of high calorific value gas. Compared with the traditional gas recovery chain conditions, the present invention is safer, the gas recovery time is increased by 90-120 seconds / furnace, and the gas recovery volume is increased by about 15m 3 / t, which increases the gas recovery volume, saves energy consumption indicators, and reduces carbon emissions, and has a high promotion value for domestic steel mills.

[0019] 2. The present invention selects a recovery mode according to the tank position of the gas holder, optimizes the gas recovery efficiency, maximizes the use effect of the gas, limits carbon emissions, and reduces energy waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a comparison chart of the start time of gas recovery between the method of the present invention and traditional methods. DETAILED DESCRIPTION

[0021] The following examples may enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way.

[0022] Example 1

[0023] 1. During normal operation of the gas tank:

[0024] ①Converter blowing ≤5min recovery and release conditions:

[0025] Recovery conditions: After the converter starts blowing, the re-blowing system starts timing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, the gas recovery system sends out recovery information, the three-way valve takes 15 seconds to open, and the gas starts to be recovered;

[0026] Emission conditions: When the O2 content is >1%, the system switches to the emission state;

[0027] ② Recovery and release conditions after 5 minutes of converter blowing:

[0028] Recovery conditions: The magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥25%;

[0029] Release conditions: When the O2 content is >1% or the CO content is <21%, the system switches to the release state.

[0030] 2. Medium calorific value recovery mode:

[0031] Recovery conditions: After the converter is started, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥25%;

[0032] Release conditions: When the CO content is <21% or the O2 content is >1%, the system switches to the release state.

[0033] 3. High calorific value recovery mode:

[0034] Recovery conditions: After the converter is started, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1%, and the CO content is ≥29%;

[0035] Release conditions: When the CO content is <25% or the O2 content is >1%, the system switches to the release state.

[0036] Figure 1 The figure is a comparison of the start time of gas recovery of the method of the present invention and the traditional method. It can be seen that the start time of gas recovery of the method of the present invention is advanced by about 75 seconds / furnace compared with the traditional method, which reduces the waste of gas and increases the recovery amount of gas.

[0037] In addition, the method of the present invention increases the converter gas recovery by 15m 3 / t, increasing negative energy steelmaking by 3.42kgce; taking an annual output of 10 million tons of steel as an example, the economic benefit per ton of increased steel is 28 million yuan; the annual carbon emissions are reduced by 82,500 tons, with significant economic benefits.

[0038] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the implementation methods. Other different forms of changes or modifications may be made based on the above description. Obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A method for increasing the recovery of converter gas, characterized in that: During the normal operation of the gas holder, the interlocking conditions of the converter blowing time are set, and the interlocking conditions include the recovery and release conditions of the converter blowing ≤ 5 minutes and the recovery and release conditions after the converter blowing 5 minutes; The recovery and emission conditions of the converter blowing ≤5min are as follows: after the converter starts blowing, the re-blowing system starts timing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, the gas recovery system sends out a recovery message, and the gas starts to be recovered; when the O2 content is >1wt%, the system switches to the emission state; The recovery and release conditions after 5 minutes of converter blowing are as follows: after 5 minutes of converter blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, and the CO content is ≥25wt%, and the gas starts to be recovered; when the O2 content is >1wt%, the system switches to the release state; or after 5 minutes of converter blowing, the magnetic oxygen analyzer of the gas recovery system detects that the O2 content is ≤1wt%, and the CO content is ≥25wt%, and the gas starts to be recovered; when the CO content is <21wt%, the system switches to the release state.

2. The method for increasing converter gas recovery according to claim 1, characterized in that: The gas recovery system sends out recovery information, and the three-way valve opens for 10-15 seconds.

3. The method for increasing converter gas recovery according to claim 1, characterized in that: The gas recovery system sends out a release message, and the three-way valve closing time is 10-15s.

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