Pressure stabilizing device for a blow tank and method of operation thereof

Abstract

The application discloses a kind of steady voltage device of injection tank and its working method, the steady voltage device includes injection tank, coal powder bin, upper cover of injection tank is equipped with inlet, pressure release port, pressure measuring port, upper fluidizer, upper temperature measuring port, injection tank body cylinder is equipped with middle fluidizer, weighing device, middle fluidizer is at least two layers along the height direction of tank body cylinder interval arrangement, injection tank lower cone section is equipped with lower fluidizer, lower temperature measuring port, discharge port, lower fluidizer is at least two layers along the height direction of lower cone section interval arrangement, and lower cone section bottom is equipped with fluidized bed;The working method determines the weight of injection tank corresponding to each layer fluidizer in advance, when coal powder injection, can be calculated according to injection tank weight display, on coal powder top surface position, close the fluidizer layer above coal powder top surface position, avoid fluidizer to empty fluidization, realize accurate fluidization to coal powder in injection tank, reduce instantaneous rate fluctuation in injection process.

Description

Technical Field

[0001] This invention relates to blast furnace pulverized coal injection systems, and more particularly to a pressure stabilizing device for an injection tank and its operating method. Background Technology

[0002] The pulverized coal injection rate in blast furnaces is a key parameter affecting blast furnace smelting efficiency, fuel consumption, and molten iron quality. Controlling the instantaneous fluctuations and cumulative hourly deviations of the pulverized coal injection rate, and avoiding furnace temperature fluctuations or incomplete combustion of pulverized coal, is an important direction for the current development of pulverized coal injection in blast furnaces. Summary of the Invention

[0003] Purpose of the invention: The purpose of this invention is to provide a pressure stabilizing device for a pulverized coal injection tank and its working method, which can achieve precise fluidization of pulverized coal in the pulverized coal injection tank of a blast furnace, maintain stable tank pressure, reduce instantaneous fluctuations in pulverized coal injection rate and hourly cumulative deviations, and avoid furnace temperature fluctuations or incomplete combustion of pulverized coal.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A pressure stabilizing device for a pulverized coal injection tank includes a pulverized coal injection tank and a pulverized coal silo. The pulverized coal injection tank includes an upper top cover, a tank body, and a lower conical section. The upper top cover is provided with a feed inlet, a pressure relief port, a pressure measuring port, an upper fluidizer, and an upper temperature measuring port. The tank body is provided with a middle fluidizer and a weighing device. The middle fluidizer is arranged in at least two layers at intervals along the height direction of the tank body. The lower conical section is provided with a lower fluidizer, a lower temperature measuring port, and a discharge port. The lower fluidizer is arranged in at least two layers at intervals along the height direction of the lower conical section. A fluidized bed is provided at the bottom of the lower conical section. The feed inlet is connected to the pulverized coal silo via a feed pipe, which is equipped with a feed control valve. The pressure relief outlet is connected to the pulverized coal silo via a pressure relief pipe, which is equipped with a pressure relief control valve. The feed pipe and the pressure relief pipe are connected via a venting valve. The upper fluidizer, middle fluidizer, and lower fluidizer are each connected to a fluidizer gas supply pipeline, which is equipped with a fluidizer inlet control valve. The discharge outlet is connected to a discharge pipeline, which is equipped with a discharge shut-off valve. The fluidized bed is connected to a fluidized bed gas supply pipeline, which is equipped with a fluidized bed inlet control valve.

[0005] Furthermore, the feed control valve includes a manual feed valve, an upper sealing valve, a lower sealing valve, and a vent valve disposed between the upper sealing valve and the lower sealing valve; the feed pipeline is provided with a feed flexible connection.

[0006] Furthermore, the pressure relief control valve includes a large pressure relief valve and a small pressure relief valve arranged in parallel, and the pressure relief pipeline is equipped with a pressure relief flexible connection.

[0007] Furthermore, each layer of middle fluidizers and lower fluidizers is evenly distributed along the circumference of the injection tank. The fluidizer air supply pipeline includes an air inlet main pipe, which is connected to the upper air inlet branch pipe, the middle air inlet branch pipe, and the lower air inlet branch pipe. The upper air inlet branch pipe is connected to the upper fluidizer. Each layer of middle fluidizers is connected to a middle air inlet branch pipe, and each layer of lower fluidizers is connected to a lower air inlet branch pipe.

[0008] Furthermore, the fluidizer intake control valve includes a first intake manual valve, a first intake flow meter, a first intake regulating valve, and a first intake shut-off valve, all installed on the intake manifold; the upper intake branch pipe, the middle intake branch pipe, and the lower intake branch pipe are each equipped with a first intake flexible connection.

[0009] Furthermore, the upper fluidizer, middle fluidizer, and lower fluidizer are all equipped with sintered filter screens, and the inlet of the upper fluidizer, middle fluidizer, and lower fluidizer is equipped with a first inlet check valve.

[0010] Furthermore, the fluidized bed is equipped with a fluidizing plate, and the fluidized bed air intake control valve includes a second air intake manual valve, a second air intake flow meter, a second air intake regulating valve, a second air intake shut-off valve, and a second air intake check valve; the fluidized bed air source pipeline is equipped with a second air intake flexible connection.

[0011] The working method of the pressure stabilizing device of the above-mentioned injection tank includes: The weight of the injection tank corresponding to each fluidizer layer is predetermined. Based on the shape of the injection tank, the volume from the top fluidizer and the middle and bottom fluidizers of each layer to the bottom of the injection tank is calculated. The volume is then multiplied by the coal powder density to obtain the weight of the injection tank corresponding to the top fluidizer and the middle and bottom fluidizers of each layer. When the pulverized coal silo is filled with pulverized coal, the pressure relief control valve is opened, the vent valve is closed, and the feed control valve is opened. The pulverized coal silo begins to fill the pulverized coal silo. When the pulverized coal silo reaches the preset weight, the feed control valve is closed and the pressure relief control valve is closed. After the pulverized coal injection tank is filled with pulverized coal, fluidizing gas is introduced into the injection tank through the fluidized bed. The fluidized bed inlet control valve is adjusted according to the preset fluidized bed inlet flow rate. The weight of the injection tank measured by the weighing device is compared with the weight of the injection tank corresponding to each layer of fluidizers. The weight is estimated to be at the top surface of the pulverized coal. Fluidizing gas is introduced into the injection tank through the upper fluidizer, middle fluidizer, and lower fluidizer located below the top surface of the pulverized coal. The fluidizer inlet control valve is adjusted according to the preset fluidizer inlet flow rate. When the internal pressure of the injection tank reaches the set value, the fluidizer inlet control valve is closed and the fluidized bed inlet control valve is adjusted to the preset value to keep the pulverized coal at the bottom of the injection tank in a fluidized state. At this time, the pressure relief control valve is opened or closed according to the pressure of the injection tank. When the injection tank is purging, the discharge shut-off valve is opened. According to the preset fluidized bed air inlet flow rate and fluidizer air inlet flow rate, the fluidizer air inlet control valve and fluidized bed air inlet control valve are adjusted respectively. According to the amount of purging, the pressure setting value of the injection tank is adjusted. The pressure relief control valve is opened or closed according to the pressure of the injection tank. During the purging process, the change in the top position of the pulverized coal is calculated based on the real-time detection of the weight of the injection tank by the weighing device. When the upper fluidizer, middle fluidizer, and lower fluidizer are above the top position of the pulverized coal, the fluidizer air inlet control valve of the fluidizer air source pipeline connected to them is closed. When the weight of the injection tank is lower than the set value, the discharge shut-off valve is closed. After the injection tank finishes injection, open the pressure relief control valve until the pressure inside the injection tank is zero.

[0012] Beneficial effects: By using the pressure stabilizing device of this injection tank, the volume from each fluidizer layer to the bottom of the injection tank can be calculated in advance based on the shape of the injection tank. This volume is then multiplied by the coal powder density to determine the weight of the injection tank corresponding to each fluidizer layer. During coal powder injection, the weight display of the injection tank can be used to estimate the position above the coal powder top surface, and the fluidizer layer above the coal powder top surface can be closed to prevent fluidization of the fluidizer into the air. This achieves precise fluidization of the coal powder inside the injection tank and reduces instantaneous rate fluctuations during injection. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the pressure stabilizing device for the injection tank.

[0014] In the diagram: 1-Pulverized coal silo; 2-Manual feed valve; 3-Upper sealing valve; 4-Feed flexible connection; 5-Lower sealing valve; 6-Vent valve; 7-Pressure relief flexible connection; 8-Large pressure relief valve; 9-Small pressure relief valve; 10-Pressure measuring port; 11-Upper temperature measuring port; 12-Weighing device; 13-First inlet check valve; 14-Middle fluidizer; 15-Lower temperature measuring port; 16-Discharge shut-off valve; 17-First inlet shut-off valve; 18-First inlet flexible connection; 19-First inlet regulating valve; 20-First inlet flow meter; 21-First inlet manual valve; 22-Second inlet manual valve; 23-Second inlet flow meter; 24-Second inlet regulating valve; 25-Second inlet shut-off valve; 26-Second inlet flexible connection; 27-Second inlet check valve; 28-Fluidized bed; 29-Upper fluidizer; 30-Lower fluidizer. Detailed Implementation

[0015] The invention will now be further explained with reference to the accompanying drawings.

[0016] like Figure 1As shown, a pressure stabilizing device for a pulverized coal injection tank according to the present invention includes a pulverized coal injection tank and a pulverized coal silo 1. The pulverized coal injection tank includes an upper top cover, a tank body, and a lower conical section. The upper top cover is provided with a feed inlet, a pressure relief port, a pressure measuring port, an upper fluidizer 29, and an upper temperature measuring port. The tank body is provided with a middle fluidizer 14 and a weighing device 12. The middle fluidizer 14 is arranged in at least two layers at intervals along the height direction of the tank body. The lower conical section is provided with a lower fluidizer 30, a lower temperature measuring port, and a discharge port. The lower fluidizer 30 is arranged in at least two layers at intervals along the height direction of the lower conical section. A fluidized bed 28 is provided at the bottom of the lower conical section.

[0017] The feed inlet is connected to the pulverized coal silo 1 via a feed pipe, which is equipped with a feed control valve. The pressure relief outlet is connected to the pulverized coal silo 1 via a pressure relief pipe, which is equipped with a pressure relief control valve. The feed pipe and the pressure relief pipe are connected via a venting valve 6. The upper fluidizer 29, the middle fluidizer 14, and the lower fluidizer 30 are respectively connected to the fluidizer gas source pipeline, which is equipped with a fluidizer inlet control valve. The discharge outlet is connected to the discharge pipeline, which is equipped with a discharge shut-off valve 16. The fluidized bed 28 is connected to the fluidized bed gas source pipeline, which is equipped with a fluidized bed inlet control valve.

[0018] The feed control valve includes a manual feed valve 2, an upper sealing valve 3, a lower sealing valve 5, and a vent valve 6 positioned between the upper sealing valve 3 and the lower sealing valve 5; the feed pipeline is equipped with a feed flexible connection 4. This is used to compensate for displacement and stress caused by vibration of the injection tank, pulverized coal silo 1, or the pipeline itself. The pressure relief control valve includes a large pressure relief valve 8 and a small pressure relief valve 9 arranged in parallel; the pressure relief pipeline is equipped with a pressure relief flexible connection 7.

[0019] In this embodiment, at least two layers of the middle fluidizer 14 are spaced apart along the height direction of the tank body, and two layers of the lower fluidizer 30 are spaced apart along the height direction of the lower conical section. Each layer of middle fluidizer 14 and lower fluidizer 30 has multiple fluidizers evenly distributed along the circumference of the injection tank. The fluidizer gas source pipeline includes an air inlet main pipe, which is connected to the upper air inlet branch pipe, the middle air inlet branch pipe, and the lower air inlet branch pipe. The upper air inlet branch pipe is connected to the upper fluidizer 29. Each layer of middle fluidizer 14 is connected to a middle air inlet branch pipe, and each layer of lower fluidizer 30 is connected to a lower air inlet branch pipe. The fluidizer inlet control valve includes a first inlet manual valve 21, a first inlet flow meter 20, and a first inlet regulating valve 19 installed on the main inlet pipe, as well as first inlet shut-off valves 17 installed on the upper, middle, and lower inlet branch pipes; each of the upper, middle, and lower inlet branch pipes is equipped with a first inlet flexible connection 18. The upper fluidizer 39, middle fluidizer 14, and lower fluidizer 30 are all equipped with sintered filters to help the fluidizing gas diffuse evenly into the injection tank. The inlets of the upper, middle, and lower fluidizers are all equipped with first inlet check valves to prevent coal dust leakage from the injection tank.

[0020] The fluidized bed 28 is equipped with a fluidizing plate. The fluidized bed air intake control valve includes a second air intake manual valve 22, a second air intake flow meter 23, a second air intake regulating valve 24, a second air intake shut-off valve 25, and a second air intake check valve 27. The fluidized bed air source pipeline is equipped with a second air intake flexible connection 26.

[0021] The operating method of the pressure stabilizing device for the injection tank of the present invention includes: The weight of the injection tank corresponding to each fluidizer layer is predetermined. Based on the shape of the injection tank, the volume from the top fluidizer and the middle and bottom fluidizers of each layer to the bottom of the injection tank is calculated. The volume is then multiplied by the coal powder density to obtain the weight of the injection tank corresponding to the top fluidizer and the middle and bottom fluidizers of each layer. When the pulverized coal silo is filled with pulverized coal, the large pressure relief valve of the pressure relief control valve is opened, the vent valve is closed, and the lower sealing valve and upper sealing valve of the feed control valve are opened in sequence. The pulverized coal silo begins to fill the pulverized coal silo. When the pulverized coal silo reaches the preset weight, the upper sealing valve and lower sealing valve of the feed control valve are closed in sequence, the large pressure relief valve of the pressure relief control valve is closed, and the vent valve is opened. After the pulverized coal injection tank is filled, fluidizing gas is introduced into the injection tank through the fluidized bed. The opening of the second intake regulating valve of the fluidized bed intake control valve is adjusted according to the preset fluidized bed intake flow rate. The weight of the injection tank measured by the weighing device is compared with the weight of the injection tank corresponding to each fluidizer layer to calculate the position of the top surface of the pulverized coal. According to this method, when the weight of the injection tank measured by the weighing device is greater than the weight of the injection tank corresponding to a certain fluidizer layer, it can be inferred that the current position of the top surface of the pulverized coal inside the injection tank is above that fluidizer layer. Conversely, when the weight of the injection tank measured by the weighing device is less than the weight of the injection tank corresponding to a certain fluidizer layer, it can be inferred that the current position of the top surface of the pulverized coal inside the injection tank is... Below the fluidizer in this layer, fluidizing gas is introduced into the injection tank through the upper, middle, and lower fluidizers located below the top surface of the pulverized coal. The opening of the first inlet regulating valve of the fluidizer inlet control valve is adjusted according to the preset fluidizer inlet flow rate. When the internal pressure of the injection tank reaches the set value, the fluidizer inlet control valve is closed, and the fluidized bed inlet control valve is adjusted to the preset value to keep the pulverized coal at the bottom of the injection tank in a fluidized state. At this time, the pressure relief control valve is opened or closed according to the pressure of the injection tank. When the pressure of the injection tank exceeds the set value, the small pressure relief valve of the pressure relief control valve is opened; when the pressure of the injection tank is lower than the set value, the small pressure relief valve of the pressure relief control valve is closed. During the blowing process, the discharge shut-off valve is opened. Based on the preset fluidized bed inlet flow rate and fluidizer inlet flow rate, the openings of the first and second inlet regulating valves of the fluidizer inlet control valve and the fluidized bed inlet control valve are adjusted respectively. The pressure setpoint of the blowing tank is adjusted according to the blowing volume. The pressure relief control valve is opened or closed according to the blowing tank pressure. When the blowing tank pressure exceeds the set value, the small pressure relief valve of the pressure relief control valve is opened; when the blowing tank pressure is lower than the set value, the small pressure relief valve of the pressure relief control valve is closed. During the blowing process, the weighing device monitors the pressure in real time. The weight of the injection tank is measured and the change in the position of the top surface of the pulverized coal is calculated. According to this method, when the weight of the injection tank measured by the weighing device changes to less than the weight of the injection tank corresponding to a certain fluidizer layer, it can be inferred that the current position of the top surface of the pulverized coal inside the injection tank has dropped below that fluidizer layer. When the upper fluidizer, middle fluidizer, and lower fluidizer are above the top surface of the pulverized coal, the fluidizer inlet control valve of the fluidizer gas source pipeline connected to it is closed to achieve precise fluidization of the pulverized coal inside the injection tank, reduce the instantaneous rate fluctuation during the injection process, and close the discharge shut-off valve when the weight of the injection tank is lower than the set value. After the purging process in the injection tank is complete, open the large pressure relief valve of the pressure relief control valve until the pressure inside the injection tank is zero. Then, start the powder filling process in the injection tank again.

[0022] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for operating a pressure stabilizing device for a spray can, characterized in that, The pressure stabilizing device of the injection tank includes an injection tank and a pulverized coal bin. The injection tank includes an upper top cover, a tank body, and a lower conical section. The upper top cover is provided with a feed inlet, a pressure relief port, a pressure measuring port, an upper fluidizer, and an upper temperature measuring port. The tank body is provided with a middle fluidizer and a weighing device. The middle fluidizer is arranged at least two layers at intervals along the height direction of the tank body. The lower conical section is provided with a lower fluidizer, a lower temperature measuring port, and a discharge port. The lower fluidizer is arranged at least two layers at intervals along the height direction of the lower conical section. A fluidized bed is provided at the bottom of the lower conical section. The feed inlet is connected to the pulverized coal silo via a feed pipe equipped with a feed control valve. The pressure relief outlet is connected to the pulverized coal silo via a pressure relief pipe equipped with a pressure relief control valve. The feed pipe and the pressure relief pipe are connected via a vent valve. The upper, middle, and lower fluidizers are each connected to a fluidizer gas supply pipeline, which is equipped with a fluidizer inlet control valve. The discharge outlet is connected to a discharge pipeline equipped with a discharge shut-off valve. The fluidized bed is connected to a fluidized bed gas supply pipeline, which is equipped with a fluidized bed inlet control valve. The working methods include: The weight of the injection tank corresponding to each fluidizer layer is predetermined. Based on the shape of the injection tank, the volume from the top fluidizer and the middle and bottom fluidizers of each layer to the bottom of the injection tank is calculated. The volume is then multiplied by the coal powder density to obtain the weight of the injection tank corresponding to the top fluidizer and the middle and bottom fluidizers of each layer. When the pulverized coal silo is filled with pulverized coal, the pressure relief control valve is opened, the vent valve is closed, and the feed control valve is opened. The pulverized coal silo begins to fill the pulverized coal silo. When the pulverized coal silo reaches the preset weight, the feed control valve is closed and the pressure relief control valve is closed. After the pulverized coal injection tank is filled with pulverized coal, fluidizing gas is introduced into the injection tank through the fluidized bed. The fluidized bed inlet control valve is adjusted according to the preset fluidized bed inlet flow rate. The weight of the injection tank measured by the weighing device is compared with the weight of the injection tank corresponding to each layer of fluidizers. The weight is estimated at the top surface of the pulverized coal. Fluidizing gas is introduced into the injection tank through the upper fluidizer, middle fluidizer, and lower fluidizer located below the top surface of the pulverized coal. The fluidizer inlet control valve is adjusted according to the preset fluidizer inlet flow rate. When the internal pressure of the injection tank reaches the set value, the fluidizer inlet control valve is closed and the fluidized bed inlet control valve is adjusted to the preset value to keep the pulverized coal at the bottom of the injection tank in a fluidized state. At this time, the pressure relief control valve is opened or closed according to the pressure of the injection tank. When the injection tank is purging, the discharge shut-off valve is opened. According to the preset fluidized bed air inlet flow rate and fluidizer air inlet flow rate, the fluidizer air inlet control valve and fluidized bed air inlet control valve are adjusted respectively. The pressure setting value of the injection tank is adjusted according to the injection volume. The pressure relief control valve is opened or closed according to the injection tank pressure. During the injection process, the change in the top position of the pulverized coal is calculated based on the real-time detection of the injection tank weight by the weighing device. When the upper fluidizer, middle fluidizer, and lower fluidizer are above the top position of the pulverized coal, the fluidizer air inlet control valve of the fluidizer air source pipeline connected to them is closed. When the weight of the injection tank is lower than the set value, the discharge shut-off valve is closed. After the injection tank finishes injection, open the pressure relief control valve until the pressure inside the injection tank is zero.

2. The working method of the pressure stabilizing device for a jet can according to claim 1, characterized in that: The feed control valve includes a manual feed valve, an upper sealing valve, a lower sealing valve, and a vent valve located between the upper sealing valve and the lower sealing valve; the feed pipeline is equipped with a feed flexible connection.

3. The working method of the pressure stabilizing device for a spray can according to claim 1, characterized in that: The pressure relief control valve includes a large pressure relief valve and a small pressure relief valve arranged in parallel, and the pressure relief pipeline is equipped with a pressure relief flexible connection.

4. The working method of the pressure stabilizing device for a jet can according to claim 1, characterized in that: Each layer of fluidizers, including the middle and lower fluidizers, is evenly distributed along the circumference of the injection tank. The fluidizer gas supply pipeline includes a main inlet pipe, which is connected to the upper, middle, and lower inlet branch pipes. The upper inlet branch pipe is connected to the upper fluidizer. Each layer of the middle fluidizer is connected to a middle inlet branch pipe, and each layer of the lower fluidizer is connected to a lower inlet branch pipe.

5. The working method of the pressure stabilizing device for a spray can according to claim 4, characterized in that: The fluidizer intake control valve includes a first intake manual valve, a first intake flow meter, and a first intake regulating valve installed on the intake manifold, as well as a first intake shut-off valve installed on the upper intake branch pipe, the middle intake branch pipe, and the lower intake branch pipe; the upper intake branch pipe, the middle intake branch pipe, and the lower intake branch pipe are all equipped with a first intake flexible connection.

6. The working method of the pressure stabilizing device for a jet can according to claim 1, characterized in that: The upper fluidizer, middle fluidizer, and lower fluidizer are all equipped with sintered filter screens, and the inlet of the upper fluidizer, middle fluidizer, and lower fluidizer is equipped with a first inlet check valve.

7. The working method of the pressure stabilizing device for a jet can according to claim 1, characterized in that: The fluidized bed is equipped with a fluidizing plate, and the fluidized bed air intake control valve includes a second air intake manual valve, a second air intake flow meter, a second air intake regulating valve, a second air intake shut-off valve, and a second air intake check valve; the fluidized bed air source pipeline is equipped with a second air intake flexible connection.

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