A blast furnace gas diffusing tower with small flow and accurate diffusion and an accurate control method

Abstract

The application discloses a blast furnace gas diffusion tower with small flow and accurate diffusion and an accurate control method. The blast furnace gas diffusion tower comprises a gas distributor, one or more main diffusion pipes, a bypass diffusion pipe with a smaller diameter than the main diffusion pipe, a combustion device connected to each main diffusion pipe and a computer control system. The bypass diffusion pipe is connected in parallel to one of the main diffusion pipes. A pressure collection point is arranged on the gas inlet main pipe. The computer control system can switch the bypass diffusion pipe and each main diffusion pipe according to the pressure on the gas inlet main pipe. The application can solve the problem of accurate measurement and regulation when the diffusion flow is small and stabilize the gas pipe network pressure by adding the bypass diffusion pipe.

Description

Technical Field

[0001] This invention relates to the field of blast furnace gas venting, specifically to a blast furnace gas venting tower capable of precise venting at low flow rates. Background Technology

[0002] Iron and steel integrated enterprises generate a large amount of blast furnace gas during the blast furnace ironmaking process, which is an extremely important secondary energy source. To release excess blast furnace gas and maintain a balance between its generation and use, blast furnace gas venting towers need to be constructed at appropriate locations within the blast furnace gas pipeline network. These venting towers not only protect the equipment but also ensure stable pressure in the blast furnace gas pipeline network, preventing disruption to other users' operations and thermal control. Furthermore, the combustion of the released gas reduces environmental pollution. Currently, blast furnace gas venting towers typically consist of one or more venting pipes of the same diameter. When the venting flow rate is small, precise metering and regulation are not possible, resulting in a lag in the venting tower's ability to stabilize the pipeline network pressure, leading to relatively large pressure fluctuations. Summary of the Invention

[0003] To overcome the above-mentioned defects, the purpose of this invention is to provide a blast furnace gas venting tower that can accurately release blast furnace gas at a small flow rate, as well as a precise control method.

[0004] To achieve the above objectives, the present invention provides a blast furnace gas venting tower capable of precise venting at low flow rates, comprising, in sequence, a gas distributor, one or more main venting pipes, a bypass venting pipe with a diameter smaller than the main venting pipes, a combustion device connected to each main venting pipe, and a computer control system; wherein,

[0005] The main vent pipes are connected from the same side of the distributor. Each main vent pipe is equipped with an electric butterfly valve, an electric blind valve, a hydraulic regulating valve, and a flow metering device in sequence.

[0006] The bypass vent pipe is connected in parallel to one of the main vent pipes. One end of the bypass vent pipe is located on the main vent pipe between the electric blind valve and the hydraulic regulating valve. The other end of the bypass vent pipe is located on the main vent pipe downstream of the flow metering device.

[0007] The bypass vent pipe is equipped with a hydraulic regulating valve and a flow metering device;

[0008] Pressure acquisition points are arranged on the gas inlet main pipe; the computer control system can control the opening and closing of the bypass vent pipe and each main vent pipe based on the pressure on the gas inlet main pipe.

[0009] Furthermore, the diameter of the gas distributor is 1.5 to 2.0 times the diameter of the main gas inlet pipe.

[0010] Furthermore, when the diameter of the gas distributor is DN≤1000, the diameter of the vent pipe is DN100; when the diameter of the gas distributor is DN≥1000, the diameter of the vent pipe is DN200.

[0011] Furthermore, the main vent pipe consists of three pipes.

[0012] Furthermore, the diameter of the bypass vent pipe is 1 / 3 to 1 / 2 of the nominal diameter of the main vent pipe.

[0013] Furthermore, three pressure sampling points are arranged on the main gas inlet pipe; the distance between the three pressure sampling points is 200-400m.

[0014] To achieve the above objectives, the present invention provides a precise control method for a blast furnace gas venting tower capable of precise venting at small flow rates. The blast furnace gas venting tower is the aforementioned blast furnace gas venting tower capable of precise venting at small flow rates. The main venting pipe consists of three pipes; the bypass venting pipe is connected to the third main venting pipe; the method is an ignition control method; the ignition control method includes the following steps:

[0015] 1) When the pipeline pressure is ≥10.2kPa and continues for a predetermined time, open the regulating valve of the bypass vent pipe. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0016] 2) When all the regulating valves of the bypass vent pipe are open, the pipeline pressure is ≥10.4kPa and continues for a predetermined time, open the regulating valve of the first main vent pipe. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0017] 3) When the regulating valve of the first main vent pipe is fully open, the pipeline pressure is ≥10.7kPa and continues for a predetermined time, the regulating valve of the second main vent pipe is opened. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If the flame goes out during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0018] 4) When the regulating valve of the No. 2 main vent pipe is fully opened, the pipeline pressure is ≥11.0 kPa and continues for a predetermined time, the regulating valve of the third main vent pipe is opened. After the ignition control system receives the trigger signal, it ignites the blast furnace gas and the blast furnace gas continues to burn. If the flame goes out during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0019] Furthermore, the method further includes a fire extinguishing control method; the fire extinguishing control method includes the following steps:

[0020] 1) When the pipeline pressure is ≤11.0kPa and continues for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the third main vent pipe until it is closed through the automatic control device.

[0021] 2) When the regulating valve of the third main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.7kPa for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the second main vent pipe until it is closed through the automatic control device.

[0022] 3) When the regulating valve of the second main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.4kPa for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the first main vent pipe until it is closed through the automatic control device.

[0023] 4) When the regulating valve of the first main vent pipe is closed, the pipeline pressure is ≤10.2kPa and continues for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the bypass vent pipe until it is closed through the automatic control device.

[0024] Furthermore, the method also includes an alarm method; the alarm method includes the following steps:

[0025] a. An alarm will sound when the pressure in the hydraulic oil main pipe is below 11MPa;

[0026] b. When the venting tower regulating valve is fully closed, a low-pressure alarm for the gas pipeline is issued if the pipeline pressure is lower than 6.0 kPa;

[0027] c. When the regulating valve of the gas venting tower is fully open, an overpressure alarm is triggered if the pipeline pressure exceeds 12.0 kPa;

[0028] d. When the pressure in the fire extinguishing nitrogen pipeline is lower than 0.1 MPa, a low-pressure alarm for purging nitrogen will be issued;

[0029] e. When the venting tower system loses power, the valves remain in their original positions. At this time, the control system is powered by the UPS and issues a power outage alarm. The solenoid valves and proportional valves are powered by the UPS.

[0030] Furthermore, the alarm also includes:

[0031] f. Hydraulic station fault alarms: low oil level alarm, oil pump fault alarm, oil temperature alarm.

[0032] g. Ignition system alarm: When the flame temperature is low, the ignition control cabinet sends a flameout signal, and the PLC sends a flameout alarm.

[0033] The present invention has the following advantages:

[0034] 1. By adding a small-diameter bypass vent pipe, the metering and regulation can be precisely controlled when the vent flow rate is small, thus stabilizing the gas pipeline pressure. At the same time, the small-diameter vent pipe, as a bypass pipe to a main vent pipe, avoids the need to add a riser and a combustion system.

[0035] 2. By adding a gas distributor before the three main vent pipes, the main pipeline pressure can be kept stable during venting, allowing for more precise control of the pipeline pressure.

[0036] 3. By setting up three pressure sampling points on the main gas inlet pipe and taking the median value of the three pressure sampling points for pressure calculation, local pressure changes can be avoided, which may lead to misjudgment of the pipeline pressure. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention. Detailed Implementation

[0038] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0040] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0041] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0042] Example 1

[0043] This invention discloses a blast furnace gas venting tower capable of precise small-flow venting, comprising a gas distributor, three main venting pipes (3), a bypass venting pipe (4), a combustion device (11), and a computer control system. The gas distributor is connected to the main gas inlet pipe, and the three main venting pipes (3) are connected from the same side of the gas distributor. The three main venting pipes (3) are sequentially equipped with an electric butterfly valve (5), an electric blind valve (6), a hydraulic regulating valve (7), and a flow metering device (8). The bypass venting pipe (4) is equipped with a hydraulic regulating valve (9) and a flow metering device (10). The bypass venting pipe (4) is connected from the hydraulic regulating valve (7) of one of the main venting pipes (3) and connected to the flow metering device (10). Three pressure acquisition points are arranged on the main gas inlet pipe. The computer control system can precisely control the ignition, extinguishing, and safety alarm of the venting tower. As shown in the figure, a bypass vent pipe is connected to a hydraulic control valve in front of a main vent pipe and then to a flow metering device. The bypass vent pipe is equipped with both a hydraulic control valve and a flow metering device. Preferably, the nominal diameter of the small-diameter bypass pipe is 1 / 3 to 1 / 2 of the nominal diameter of the main vent pipe.

[0044] Three pressure sampling points are arranged on the main gas inlet pipe. Preferably, the distance between the three pressure sampling points is 200-400m. Preferably, all three pressure sampling points are located on the main gas pipe in the plant area.

[0045] The computer control system can precisely control the ignition, fire extinguishing, and safety alarm of the venting tower based on the pressure collected from three pressure acquisition points.

[0046] Example 2

[0047] Based on the above embodiments, in this embodiment, the gas distributor is connected to the gas inlet main pipe. Preferably, the gas inlet main pipe is inserted into the gas distributor horizontally. Preferably, the gas inlet main pipe is inserted near the middle of the gas distributor. Preferably, the diameter of the gas distributor is 1.5 to 2.0 times the diameter of the gas inlet main pipe.

[0048] Example 3

[0049] Based on the above embodiments, in this embodiment, the gas distributor is sealed at both ends with internally welded plugs, and a vent pipe is installed in front of the internally welded plugs. Preferably, the internally welded plugs are 500-800mm away from the ends of the gas distributor. Preferably, the vent pipe is 200-400mm away from the internally welded plugs. Preferably, when the gas distributor pipe diameter is DN≤1000, the vent pipe diameter is DN100; when the gas distributor pipe diameter is DN≥1000, the vent pipe diameter is DN200.

[0050] The three main vent pipes extend from the same side of the gas distributor. Preferably, the three main vent pipes extend horizontally from the same side of the gas distributor. Preferably, the net distance between the main vent pipes on both sides and the inner welded plug plate is 300-500 mm. Preferably, the net distance between the main vent pipes on both sides and the inner welded plug plate is 300-500 mm. Preferably, the nominal diameter of the gas distributor is 1.7-2.0 times the nominal diameter of the main vent pipes.

[0051] Example 4

[0052] This embodiment describes an ignition control method for the computer control system described in the above embodiments:

[0053] a. When the pipeline pressure is ≥10.2 kPa and remains so for 10 seconds (both the set pressure and duration of the venting tower are adjustable by PLC), open the regulating valve of the bypass venting pipe. After receiving the trigger signal, the ignition control system ignites the blast furnace gas, which then continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0054] b. When all regulating valves of the bypass vent pipe are open, and the pipeline pressure is ≥10.4 kPa for 10 seconds, open the regulating valve of the No. 1 main vent pipe. After receiving the trigger signal, the ignition control system ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0055] c. Once the regulating valve of the No. 1 main vent pipe is fully open, and the pipeline pressure is ≥10.7 kPa for 10 seconds, open the regulating valve of the No. 2 main vent pipe. After receiving the trigger signal, the ignition control system ignites the blast furnace gas, which then continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure must be repeated until stable combustion is achieved.

[0056] d. Once the regulating valve of the No. 2 main vent pipe is fully open, and the pipeline pressure is ≥11.0 kPa for 10 seconds, open the regulating valve of the No. 3 main vent pipe. After receiving the trigger signal, the ignition control system will ignite the blast furnace gas, which will continue to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

[0057] Example 5

[0058] This embodiment describes a fire suppression control method using the computer control system described in the above embodiments.

[0059] a. When the pipeline pressure is ≤11.0kPa and lasts for 10 seconds (both the set pressure and duration of the venting tower are adjustable by PLC), after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the No. 3 main venting pipe until it is closed through the automatic control device.

[0060] b. When the regulating valve of the No. 3 main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.7kPa for 10 seconds, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the No. 2 main vent pipe until it is closed through the automatic control device.

[0061] c. When the regulating valve of the No. 2 main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.4kPa for 10 seconds, the ignition control system receives the trigger signal and then uses the automatic control device to slowly reduce the opening of the regulating valve of the No. 1 main vent pipe until it is closed.

[0062] d. When the regulating valve of the No. 1 main vent pipe is closed, the pipeline pressure is ≤10.2kPa and lasts for 10 seconds (the set pressure and duration of the vent tower are adjustable by PLC), after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the bypass vent pipe until it is closed through the automatic control device.

[0063] Example 6

[0064] This embodiment describes a method for setting alarms in the computer control system described in the above embodiments:

[0065] a. An alarm will sound when the pressure in the hydraulic oil main pipe is below 11MPa;

[0066] b. When the venting tower regulating valve is fully closed, if the pipeline pressure is lower than 6.0 kPa (adjustable), a low-pressure alarm for the gas pipeline will be issued;

[0067] c. When the regulating valve of the gas venting tower is fully open, if the pipeline pressure is higher than 12.0 kPa (adjustable), an overpressure alarm for the gas pipeline will be issued.

[0068] d. When the pressure in the fire extinguishing nitrogen pipeline is lower than 0.1 MPa, a low-pressure alarm for purging nitrogen will be issued;

[0069] e. When the venting tower system loses power, the valves remain in their original positions. At this time, the control system is powered by UPS and issues a power outage alarm. The solenoid valves and proportional valves can be powered by UPS.

[0070] f. Hydraulic station fault alarms: low oil level alarm, oil pump fault alarm, oil temperature alarm.

[0071] g. Ignition system alarm: When the flame temperature is low, the ignition control cabinet sends a flameout signal, and the PLC sends a flameout alarm.

[0072] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0073] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A blast furnace gas venting tower capable of precise venting at low flow rates, characterized in that, It includes, in sequence, a gas distributor, one or more main vent pipes, a bypass vent pipe with a diameter smaller than the main vent pipe, a combustion device connected to each main vent pipe, and a computer control system; wherein, The gas distributor is connected to the gas inlet main pipe, and the main vent pipe is connected from the same side of the gas distributor. Each main vent pipe is equipped with an electric butterfly valve, an electric blind valve, a hydraulic regulating valve and a flow metering device in sequence. The bypass vent pipe is connected in parallel to one of the main vent pipes. One end of the bypass vent pipe is located on the main vent pipe between the electric blind valve and the hydraulic regulating valve. The other end of the bypass vent pipe is located on the main vent pipe downstream of the flow metering device. The bypass vent pipe is equipped with a hydraulic regulating valve and a flow metering device; Pressure acquisition points are arranged on the gas inlet main pipe; the computer control system can control the opening and closing of the bypass vent pipe and each main vent pipe based on the pressure on the gas inlet main pipe.

2. The blast furnace gas venting tower with precise small-flow-rate venting as described in claim 1, characterized in that, The diameter of the gas distributor is 1.5 to 2.0 times the diameter of the main gas inlet pipe.

3. The blast furnace gas venting tower with precise small-flow-rate venting as described in claim 1, characterized in that, When the diameter of the gas distributor is DN≤1000, the diameter of the vent pipe is DN100; when the diameter of the gas distributor is DN≥1000, the diameter of the vent pipe is DN200.

4. The blast furnace gas venting tower with precise small-flow-rate venting as described in claim 1, characterized in that, The main vent pipe consists of three pipes.

5. The blast furnace gas venting tower capable of precise small-flow venting as described in claim 1, characterized in that, The diameter of the bypass vent pipe is 1 / 3 to 1 / 2 of the nominal diameter of the main vent pipe.

6. The blast furnace gas venting tower capable of precise small-flow venting as described in claim 1, characterized in that, Three pressure sampling points are arranged on the main gas inlet pipe; the distance between the three pressure sampling points is 200-400m.

7. A precise control method for a blast furnace gas venting tower capable of precise venting at small flow rates, wherein the blast furnace gas venting tower is the blast furnace gas venting tower capable of precise venting at small flow rates as described in claim 1, and the main venting pipe has three sections; the bypass venting pipe is connected to the third main venting pipe; characterized in that, The method described is an ignition control method; the ignition control method includes the following steps: 1) When the pipeline pressure is ≥10.2kPa and continues for a predetermined time, open the regulating valve of the bypass vent pipe. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved. b. When all the regulating valves of the bypass vent pipe are open, the pipeline pressure is ≥10.4kPa and continues for a predetermined time, open the regulating valve of the first main vent pipe. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved. c. When all the regulating valves of the first main vent pipe are open, the pipeline pressure is ≥10.7kPa and continues for a predetermined time, the regulating valve of the second main vent pipe is opened. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved. d. When the regulating valve of the No. 2 main vent pipe is fully open, the pipeline pressure is ≥11.0 kPa and continues for a predetermined time, open the regulating valve of the third main vent pipe. After the ignition control system receives the trigger signal, it ignites the blast furnace gas, and the blast furnace gas continues to burn. If flameout occurs during the venting process, the above venting and ignition procedure needs to be repeated until stable combustion is achieved.

8. The precise control method for a blast furnace gas venting tower capable of precise small-flow venting as described in claim 7, characterized in that, The method further includes a fire extinguishing control method; the fire extinguishing control method includes the following steps: 1) When the pipeline pressure is ≤11.0kPa and continues for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the third main vent pipe until it is closed through the automatic control device. 2) When the regulating valve of the third main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.7kPa for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the second main vent pipe until it is closed through the automatic control device. 3) When the regulating valve of the second main vent pipe is closed, and the pipeline pressure continues to drop to ≤10.4kPa for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the first main vent pipe until it is closed through the automatic control device. 4) When the regulating valve of the first main vent pipe is closed, the pipeline pressure is ≤10.2kPa and continues for a predetermined time, after the ignition control system receives the trigger signal, it will gradually reduce the opening of the regulating valve of the bypass vent pipe until it is closed through the automatic control device.

9. The precise control method for a blast furnace gas venting tower capable of precise small-flow venting as described in claim 7, characterized in that, The method further includes an alarm method; the alarm method includes the following steps: a. An alarm will sound when the pressure in the hydraulic oil main pipe is below 11MPa; b. When the venting tower regulating valve is fully closed, a low-pressure alarm for the gas pipeline is issued if the pipeline pressure is lower than 6.0 kPa; c. When the regulating valve of the gas venting tower is fully open, an overpressure alarm is triggered if the pipeline pressure exceeds 12.0 kPa; d. When the pressure in the fire extinguishing nitrogen pipeline is lower than 0.1 MPa, a low-pressure alarm for purging nitrogen will be issued; e. When the venting tower system loses power, the valves remain in their original positions. At this time, the control system is powered by the UPS and issues a power outage alarm. The solenoid valves and proportional valves are powered by the UPS.

10. The precise control method for a blast furnace gas venting tower capable of precise small-flow venting as described in claim 9, characterized in that, The alarm also includes: f. Hydraulic station fault alarms: low oil level alarm, oil pump fault alarm, oil temperature alarm; g. Ignition system alarm: When the flame temperature is low, the ignition control cabinet sends a flameout signal, and the PLC sends a flameout alarm.

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