Blast furnace coal injection safety cut-off device and method

Abstract

The invention relates to a blast furnace coal injection safety cut-off device and a blast furnace coal injection safety cut-off method, an existing blast furnace anti-backfire device is transformed, and the blast furnace coal injection safety cut-off device comprises an inlet pipeline, a cut-off bent pipe, an outlet pipeline, an impurity discharging pipeline and a cut-off ball; according to the sealing device, by arranging all the components and setting the matching mode, airflow stability in the normal use process is achieved, the scouring amount of all connecting points of the device by high-speed airflow is greatly reduced, rapid and efficient sealing can be achieved during stopping and reverse sealing, and efficient blockage clearing and efficient diffusion can be achieved during impurity clearing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel metallurgical equipment, and particularly relates to a blast furnace coal injection safety cutoff device and method. BACKGROUND

[0002] The blast furnace coal injection is an important stage in the steel metallurgical ironmaking stage. In the coal injection process, the coal needs to be dried, rolled and separated, and then ground into qualified coal powder. Then the coal powder is injected into the blast furnace through the blast furnace tuyere by the carrier gas. In the coal injection process, the injection gun often appears abnormal, so the existing coal powder injection gun is usually equipped with a check valve. However, the check valve generally needs to be operated manually, which has a certain hysteresis. If the coal powder injection gun can automatically judge the non-injection of coal and automatically perform the check operation, the safety of the coal powder injection will be greatly improved. In view of the above technical problems, the researchers designed a coal injection anti-backfire device. Chinese patent application publication CN110724779A discloses a blast furnace ironmaking coal powder injection gun check valve and a check method, and Chinese patent application publication CN117187456A discloses a new coal injection anti-backfire device. The two technical solutions and the same applicant's similar technical solutions all set a bend pipe in communication with the powder outlet steel pipe and the powder inlet steel pipe, and set an anti-backfire ball in the bend pipe. When the coal powder injection gun is normally operated, the anti-backfire ball is impacted by the gas flow to the top end of the bend pipe, and the coal powder normally passes through the powder inlet steel pipe and the powder outlet steel pipe. When the coal powder injection gun fails, the anti-backfire ball falls due to the disappearance of the coal powder gas flow, and then generates a reverse gas flow due to the gas pressure in the blast furnace, so that the anti-backfire ball blocks the powder inlet steel pipe, thereby preventing the gas flow in the blast furnace from flowing outward and avoiding safety accidents. However, impurities (including scale generated due to high temperature during injection) are generated in the pipeline during the coal injection process. These technical solutions do not study the impurity removal components. If the impurity removal components are set at the tail of the powder outlet steel pipe as general impurity removal components, the impurities will mainly appear near the bend pipe, and the impurities will not be completely removed if the impurity removal components are set at the tail of the powder outlet steel pipe, which will cause serious scale in the bend pipe, thereby affecting the normal operation of the ball and the sealing.

[0003] Chinese utility model publication CN216242336U discloses a coal injection gun anti-backfire device. The second ceramic lining is set to enable the ceramic ball to better dynamically stay during normal operation. However, since the ceramic lining needs to be set, each component needs to be welded, so that the welding position is easy to form a gas flow impact point, thereby causing unstable gas flow and increased loss.

[0004] The Chinese patent CN114962742B discloses a coal injection anti-backfire device, which limits the movement of ceramic balls by setting connecting parts and connecting cylinders, but the structure of each part for limiting is complex, and the safety and stability during high-temperature working process need to be discussed. SUMMARY

[0005] In view of the above technical problems, the purpose of the present application is to provide a blast furnace coal injection safety cutoff device and method.

[0006] The purpose of the present application is achieved by the following technical means: A blast furnace coal injection safety cutoff device, comprising a cutoff ball and an integrally cast inlet pipe, cutoff elbow, outlet pipe and impurity removal pipe.

[0007] The inlet pipe comprises an inlet pipe body, an inlet end, a valve seat and an inlet pipe connecting end.

[0008] The cutoff elbow comprises an arc pipe body, an arc pipe inlet end, an arc pipe side opening end and an arc pipe top end.

[0009] The outlet pipe comprises an outlet pipe body, an outlet pipe connecting end and an outlet end.

[0010] The impurity removal pipe comprises an impurity removal pipe body, an impurity removal pipe inlet end and an impurity removal pipe outlet end.

[0011] The inlet end of the inlet pipe is connected to the outlet of the injection pipe of the coal injection system, and the inlet pipe connecting end is in communication with the arc pipe inlet end.

[0012] The arc pipe body is arranged as an arc-shaped pipe with a side opening as the arc pipe side opening end, the arc pipe side opening end is arranged opposite to the arc pipe inlet end, and the mathematical axis center line of the arc pipe side opening end is parallel to or coincides with the mathematical axis center line of the inlet pipe body, the arc pipe side opening end is in communication with the outlet pipe connecting end, and the arc pipe top end is provided with a cover.

[0013] The outlet end of the outlet pipe is connected to the inlet of the pulverized coal injection gun.

[0014] The impurity removal pipe body is vertically provided on the bottom wall of the outlet pipe body, the impurity removal pipe inlet end is in communication with the inside of the outlet pipe body, and the mathematical axis center line of the pipe at the arc pipe top end is parallel to the mathematical axis center line of the impurity removal pipe body.

[0015] The cutoff ball is arranged in the arc pipe body, and the diameter of the cutoff ball is D 球 , the inner diameter of the arc pipe body is D 弧 , the inner diameter of the inlet pipe body is D 入 , the inner diameter of the outlet pipe body is D 出 , D 入 =D 出 , and D 弧 :D球 :D 入 = (30~34): (26~29): (22~25).

[0016] The distance between the mathematical axis of the pipe at the top of the arc pipe and the mathematical axis of the main body of the waste discharge pipe is L1, and the inner diameter of the main body of the waste discharge pipe is D. 杂 The condition 0 ≤ L1 < 0.15D is satisfied. 杂 .

[0017] The mass of the stopping ball is M 球 The flow rate of pulverized coal discharged into the inlet pipe is V. 煤 It meets the requirement of 0.052V. 煤 <M 球 <0.19V 煤 M 球 The unit is kg, V 煤 Unit: kg / s.

[0018] The blast furnace pulverized coal injection safety shut-off device is integrally cast.

[0019] Preferably, the mathematical axis of the arc tube body is a quarter-circular arc, and the radius of the inner arc segment of the arc tube body is R. 内 The radius of the outer arc segment of the arc tube body is R. 外 Satisfying R 外 / R 内 = (68~75): (26~30).

[0020] Preferably, the mathematical axis of the outlet pipe body coincides with the mathematical axis of the inlet pipe body, or the distance between the mathematical axis of the outlet pipe body and the mathematical axis of the inlet pipe body is less than or equal to 3 mm.

[0021] Preferably, the outer wall of the outlet end of the waste discharge pipe is provided with external threads, and a sealing nut is provided at the outlet end of the waste discharge pipe.

[0022] Preferably, the stop ball is a silicon nitride ceramic ball, a zirconia ceramic ball, or a steel ball.

[0023] Preferably, the inlet end of the discharge pipe is provided with a downwardly curved chamfer at the junction of the outlet pipe body and the discharge pipe inlet end.

[0024] Preferably, the bottom end of the connection between the inlet and outlet pipes of the arc pipe is designed with a rounded chamfer.

[0025] Preferably, axial steps are provided on both the inlet pipe body and the outer wall of the inlet end of the inlet pipe.

[0026] Preferably, a axial step is provided on the outer wall of the outlet pipe body of the outlet pipe.

[0027] Preferably, a chamfer is provided at the inlet pipe connection end. In the closed state, the stop ball contacts the chamfer to achieve a seal. The contact point between the stop ball and the chamfer forms a circular line with a diameter of D. 密封 Satisfying D 密封 / D 球 =0.86~0.92.

[0028] Preferably, the length of the outlet pipe body is greater than or equal to 100 mm.

[0029] Preferably, the distance between the top of the arc tube and the mathematical axis of the inlet tube body is L2, satisfying L2>D. 球 , and L2:D 球 = (42~50): (25~30).

[0030] As a preferred option, the mass of the stop sphere is M. 球 The flow rate of pulverized coal discharged into the inlet pipe is V. 煤 It meets the requirement of 0.052V. 煤 <M 球 <0.090V 煤 M 球 The unit is kg, V 煤 Unit: kg / s.

[0031] A method for safely shutting off pulverized coal injection in a blast furnace, the method using the aforementioned pulverized coal injection safety shut-off device, includes the following steps: (1) The above-mentioned blast furnace pulverized coal injection safety shut-off device is cast in one piece.

[0032] (2) Connect the blast furnace pulverized coal injection safety shut-off device obtained by integral casting in step (1) to the outlet of the pulverized coal injection system through the inlet end of the inlet pipe and the outlet end of the outlet pipe to the inlet of the pulverized coal injection gun. The whole device is installed on the blast furnace; the shut-off ball is installed through the top of the arc tube of the shut-off bend and the cover is tightened.

[0033] (3) Start the pulverized coal injection device to carry out pulverized coal injection in the blast furnace. The stop ball is impacted by pulverized coal and airflow to the stop bend near the top of the arc tube and continues to rotate under continuous impact.

[0034] (4) When any component in the pulverized coal injection device malfunctions or loses power, the flow of pulverized coal and carrier gas in the blast furnace pulverized coal injection safety shut-off device decreases or disappears, the shut-off ball falls to the bottom of the shut-off bend, the gas pressure inside the blast furnace is greater than the gas pressure of the pulverized coal and carrier gas flow, the gas flow direction inside the blast furnace pulverized coal injection safety shut-off device changes direction, the fallen shut-off ball is blown to the inlet pipe connection end of the inlet pipe to achieve one-way sealing, and due to the continuous existence of blast furnace gas pressure, the shut-off ball continues to maintain close contact with the inlet pipe connection end of the inlet pipe.

[0035] (5) When the pulverized coal injection device is cleared, the pulverized coal and carrier gas flow are discharged at high speed through the inlet pipe. The stop ball is impacted by the pulverized coal and air flow to the stop bend near the top of the arc pipe and continues to rotate under the continuous impact.

[0036] (6) After the overall pulverized coal injection operation is completed, unscrew the sealing nut at the outlet end of the discharge pipe, insert the steel rod from bottom to top, and break the scale deposited inside the pulverized coal injection safety shut-off device of the blast furnace. The scale is discharged downward through the discharge pipe, and then tighten the sealing nut at the outlet end of the discharge pipe.

[0037] The ranges defined by "upper", "lower", "left", "right", "front", "rear", and "middle" in this invention are relative positions in a specific state, not absolute positions, and do not limit the range of the device or components.

[0038] The technical advantages of this invention are as follows: 1. Based on existing technology, this invention incorporates a waste discharge pipe (primarily used for clearing blockages and releasing waste). Specifically, the waste discharge pipe is positioned near the stop bend of the outlet pipe, below it (its location is defined by a specific distance ratio). This allows for the placement of the waste discharge pipe at the location most prone to fouling. The stop bend is prone to fouling due to turbulent airflow. Because the waste discharge pipe is downward-facing (although the bottom is closed during operation), existing designs inevitably experience airflow impact with the pipe opening when high-speed airflow passes through this area. This not only causes airflow turbulence but, more importantly, leads to excessive wear at the opening due to the long-term impact of high-speed airflow and coal dust carried by the airflow, preventing waste discharge and ultimately damaging the entire device. This invention limits the location of the discharge pipe by a specific distance ratio. The discharge pipe is positioned below the stop bend near the outlet pipe. During normal operation, after the airflow enters through the inlet pipe, the inner diameter of the stop bend is larger than that of the inlet pipe, inevitably causing the pipe diameter to expand and resulting in turbulence. However, because this invention sets the inner diameter of the outlet pipe to be the same as that of the inlet pipe, the airflow tends to stabilize after entering the outlet pipe. Furthermore, since the bottom of the stop bend is arc-shaped and connects to the outlet pipe, the area immediately following the connection point is where the airflow has less contact. Therefore, the location of the discharge pipe inlet at this point is not subject to excessive airflow impact, further ensuring the reliability of the overall device. If the discharge pipe inlet is moved further towards the outlet pipe, it will not only be farther from the area with the most internal debris, making effective discharge impossible, but it will also be farther from the area immediately following the connection point, increasing the impact of the airflow on the discharge pipe inlet. Therefore, this invention limits its position to a specific location below the stop bend near the outlet pipe by a specific distance ratio. This not only places it in the location where the most dirt is generated, thus achieving effective dirt removal, but also avoids the excessive impact of high-speed airflow, which could cause the device to become unreliable.

[0039] 2. Based on existing technology, this invention first constructs the overall blast furnace pulverized coal injection safety shut-off device using a one-piece casting method, whereas existing devices are welded. One-piece casting avoids the impact points that occur at the welded joints of existing components. As mentioned above, one-piece casting not only results in a more rational structure and smooth transitions of internal edges, but more importantly, it allows for flexible selection of casting materials, such as carbon steel, stainless steel, and alloy steel. The wear resistance of the material can be flexibly adjusted according to usage requirements, a goal that existing welding methods cannot achieve. Furthermore, this invention, through one-piece casting combined with the specific diameter relationship of the shut-off spheres and the identical inner diameters of the inlet and outlet pipes, reduces the impact of high-speed airflow on various connections, thereby significantly improving the overall reliability of the device.

[0040] 3. By setting the inner diameter of the inlet and outlet pipes to be the same, the inlet and outlet pipes remain unchanged. Although the diameter increases when passing through the stop bend, causing a change in the airflow velocity from the inlet pipe to the horizontal section of the stop bend (due to the increased diameter, the instantaneous airflow velocity at this point decreases slightly), resulting in turbulence, the inner diameter of the outlet pipe remains unchanged relative to the inlet pipe. After passing through the horizontal section of the stop bend, the high-speed airflow velocity returns to its previous value due to the restoration of the inner diameter, preventing excessive turbulence. This further weakens the impact of high-speed airflow on the connection points of the device, thereby improving the overall lifespan and reliability of the device.

[0041] 4. This invention, by defining the relationship between the diameter of the ball, the inner diameter of the stop tube, and the inner diameter of the inlet pipe (or outlet pipe), achieves stable rotation of the stop ball under the impact of high-speed airflow at the upper part of the stop bend during normal operation. This diameter relationship prevents excessive friction between the stop ball and the inner wall of the stop bend. Simultaneously, during abnormal operation, the diameter matching allows the stop ball to more completely adhere to the inlet pipe connection end, achieving efficient one-way sealing. If the stop ball is too small, excessive entry into the inlet pipe connection end opening will inevitably cause friction between the stop ball and the inner wall of the pipe after the high-speed airflow re-enters during normal operation. If the stop ball is too large, efficient sealing is difficult, and excessive friction with the inner wall of the stop bend is likely. Furthermore, in the preferred technical solution, by setting the arc tube body to a 1 / 4 arc shape and specifying the arc radius ratio, the stop ball is less likely to collide and rub excessively with the inner wall within the arc tube body during operation, thereby improving the reliability of the device.

[0042] 5. In addition to limiting the relationship between the diameter of the stop ball and the inner diameter of other tubes, this invention also sets the relationship between the mass of the stop ball and the airflow velocity to ensure that the ball does not fall and that the stop ball can be basically kept in the upper part of the arc tube body. If the mass is too small, it will have too much contact with the cap, resulting in instability. If the mass is too large, it will easily fall to the horizontal position of the arc tube body, thus affecting the normal and uniform flow of airflow. By setting the relationship between the mass of the stop ball and the airflow velocity in this invention, the stop ball can be continuously and uniformly suspended and rotated at a higher position of the arc tube body below the cap.

[0043] 6. In the preferred embodiment, the open design of each part, with wear-resistant coating sprayed on the inner wall and key parts, allows for a coating thickness of 20-50 μm when integrally cast, with minimal impact on the inner diameter. In contrast, the thickness of the ceramic lining coating in other non-integral cast devices is generally 1.5-2 mm, and the impact on the inner diameter of the output pipe is too great when the outer diameter cannot be changed. This invention achieves efficient sealing between the stop ball and the inlet pipe by specifically setting the chamfer and the size of the chamfer at the inlet pipe connection end (defined by the ratio between the diameter of the ball and the diameter of the circle formed by the contact line). Preferably, by setting the length of the outlet pipe body to be greater than 100 mm, the turbulence caused by the slightly larger diameter of the stop bend relative to the inlet pipe is effectively rectified after entering the outlet pipe body due to the longer constant diameter setting, resulting in a more uniform and stable airflow. This avoids the scouring of contact points due to overall airflow instability, thereby improving the overall reliability of the device. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the external structure of a blast furnace pulverized coal injection safety shut-off device according to one embodiment of the present invention.

[0046] Figure 2 This is a right-side structural schematic diagram of a blast furnace pulverized coal injection safety shut-off device according to an embodiment of the present invention.

[0047] Figure 3 for Figure 2 A schematic diagram of the structure viewed in section AA.

[0048] Figure 4 This is a cross-sectional schematic diagram of a blast furnace pulverized coal injection safety shut-off device with a shut-off ball inserted, according to one embodiment of the present invention.

[0049] Figure 5 This is a cross-sectional schematic diagram of the airflow within the blast furnace pulverized coal injection safety shut-off device during normal operation, according to one embodiment of the present invention.

[0050] Figure 6 This is a cross-sectional schematic diagram of the internal structure of the blast furnace pulverized coal injection safety shut-off device in the shut-off and sealing state according to one embodiment of the present invention.

[0051] Figure 7 This is a schematic diagram of the external structure of the inlet pipe according to one embodiment of the present invention.

[0052] Figure 8 This is a cross-sectional view of a cutoff bend according to one embodiment of the present invention.

[0053] Figure 9 This is a cross-sectional structural diagram of the outlet pipe and the waste discharge pipe according to one embodiment of the present invention.

[0054] Figure 10 This is a cross-sectional schematic diagram of the structure of the stop ball and the inlet pipe in the stop-sealing state according to one embodiment of the present invention.

[0055] in: 100-Inlet pipe, 101-Inlet pipe body, 102-Inlet end, 103-Valve seat, 104-Inlet pipe connection end, 141-Connection end chamfer, 142-Contact line between chamfer and stop ball, 105-Mathematical axis of inlet pipe body; 200 - Cut-off bend, 201 - Arc pipe body, 202 - Arc pipe inlet end, 203 - Arc pipe side end, 204 - Arc pipe top end, 205 - Mathematical axis line at the top of the arc pipe, 251 - Mathematical axis line at the side end of the arc pipe, 206 - Cap; 300 - Outlet pipe, 301 - Outlet pipe body, 302 - Outlet pipe connection end, 321 - Rounded chamfer at the bottom of the arc pipe inlet end and the outlet pipe connection end, 303 - Outlet end; 400 - Discharge pipe, 401 - Discharge pipe body, 402 - Discharge pipe inlet end, 403 - Discharge pipe outlet end, 404 - Mathematical axis of the discharge pipe body, 405 - Chamfer at the junction of the discharge pipe inlet end and the outlet pipe body; 500-Cutoff Ball; D 球 - The diameter of the stop sphere, D 弧 -Inner diameter of the arc tube body, D 入 -Inner diameter of the inlet pipe body, D 出 -Inner diameter of the outlet pipe body, R 内 - The radius of the inner arc segment of the arc tube body, R 外 - The radius of the outer arc segment of the arc tube body; IN - Pulverized coal and carrier gas; OU - Gas flow discharged from the blast furnace.

[0056] Figure 5 and Figure 6The arrows in the diagram indicate the direction of gas flow.

[0057] To distinguish them, the spline curves in the numerical labels of the figure represent a component that contains multiple parts, while the straight lines in the numerical labels represent the specific parts of each component. Detailed Implementation

[0059] The process technology solution of the present invention will be further described below with reference to embodiments and accompanying drawings. Unless otherwise specified, each feature is merely one example of a series of equivalent or similar features. These embodiments are merely for the purpose of aiding understanding the present invention and should not be considered as specific limitations thereof.

[0060] Example 1 This implementation example Figures 1 to 3 , Figures 5 to 8 As shown, a blast furnace pulverized coal injection safety shut-off device according to one embodiment is illustrated, including an inlet pipe 100, a shut-off bend 200, an outlet pipe 300, a waste discharge pipe 400, and a shut-off ball 500.

[0061] As a further description, such as Figure 1 and Figure 7 As shown, the inlet pipe 100 includes an inlet pipe body 101, an inlet end 102, a valve seat 103, and an inlet pipe connection end 104.

[0062] like Figure 1 and Figure 8 As shown, the cut-off bend 200 includes an arc tube body 201, an arc tube inlet end 202, an arc tube side outlet end 203, and an arc tube top end 204.

[0063] like Figure 1 and Figure 9 As shown, the outlet pipe 300 includes an outlet pipe body 301, an outlet pipe connection end 302, and an outlet end 303.

[0064] like Figure 1 and Figure 9 As shown, the waste discharge pipe 400 includes a waste discharge pipe body 401, a waste discharge pipe inlet end 402, and a waste discharge pipe outlet end 403.

[0065] like Figure 3 As shown, the inlet end 102 of the inlet pipe 100 is connected to the injection branch pipe or injection pipe outlet of the pulverized coal injection system, and the inlet pipe connection end 104 is connected to the arc pipe inlet end 202.

[0066] like Figure 3As shown, the arc pipe body 201 is an arc-shaped pipe with a side opening of arc pipe side opening end 203. The arc pipe side opening end 203 is arranged opposite to the arc pipe inlet end 202, and the mathematical axis 231 of the arc pipe side opening end is parallel or coincident with the mathematical axis 105 of the inlet pipe body. The arc pipe side opening end 203 is connected to the outlet pipe connection end 302.

[0067] As a further description, such as Figure 5 As shown, a cap 206 is provided at the top end 204 of the arc tube.

[0068] During the operation, the outlet end 303 of the outlet pipe 300 is connected to the inlet of the blast furnace pulverized coal injection nozzle.

[0069] like Figure 3 As shown, the discharge pipe body 401 is vertically opened on the bottom wall of the outlet pipe body 301. The discharge pipe inlet end 402 is connected to the interior of the outlet pipe body 301. The mathematical axis 205 at the top of the arc pipe is parallel to the mathematical axis 404 of the discharge pipe body.

[0070] The stop ball 500 is disposed inside the arc tube body 201. In this embodiment, the diameter D of the stop ball 500 is... 球 The inner diameter D of the arc tube body 201 is 28mm. 弧 The inner diameter D of the inlet pipe body 101 is 32.5mm. 入 The inner diameter D of the outlet pipe body 301 is 24mm. 出 It is 24mm, which meets D. 入 =D 出 The requirements, and D 弧 :D 球 :D 入 =32.5:28:24, which satisfies the requirement of (30~34):(26~29):(22~25).

[0071] The mass M of the ball is 500. 球 The concentration is 31.2g (0.0312kg), and the flow rate V of the pulverized coal discharged into the inlet pipe is... 煤 It is 0.49 kg / s, M 球 / V 煤 ≈0.637, which satisfies 0.052V. 煤 <M 球 <0.19V 煤 Requirements.

[0072] The blast furnace pulverized coal injection safety shut-off device is integrally cast.

[0073] like Figure 3 As shown, in this embodiment, the mathematical axis of the arc tube body is a 1 / 4 arc segment, and the radius R of the inner arc segment of the arc tube body 201 is... 内The radius R of the outer arc segment of the arc tube body 201 is 28.75mm. 外 It is 71.25mm, which meets the R requirement. 外 / R 内 =71.25:28.75, which satisfies the requirement of (68~75):(26~30).

[0074] In other embodiments, the mathematical axis of the outlet pipe body coincides with the mathematical axis 105 of the inlet pipe body; in this embodiment, for example... Figure 3 The distance between the mathematical axis of the outlet pipe body and the mathematical axis 105 of the inlet pipe body is less than or equal to 3 mm.

[0075] As a further description, the outer wall of the outlet end 403 of the waste discharge pipe is provided with external threads, and a sealing nut is provided at the outlet end 403 of the waste discharge pipe for sealing the outlet end of the waste discharge pipe when needed.

[0076] In this embodiment, the stop ball 500 is a silicon nitride ceramic ball.

[0077] like Figure 1 As shown, axial steps are provided on the outer walls of both the inlet pipe body 101 and the inlet end 102 of the inlet pipe 100. A axial step is also provided on the outer wall of the outlet pipe body 301 of the outlet pipe 300.

[0078] like Figure 10 As shown in the diagram (since these are all schematic diagrams, the chamfer 141 is not shown in detail in other accompanying drawings, but is shown in detail in this diagram), a chamfer 141 is provided at the inlet pipe connection end. In the closed state, the stop ball contacts the chamfer to achieve a seal. The contact point between the stop ball and the chamfer forms a circular line, that is, a contact line 142 between the chamfer and the stop ball is formed. In this embodiment, the diameter D of this circular line is... 密封 If the value is 25.2, then D 密封 / D 球 ≈0.9, satisfying D 密封 / D 球 The requirement of 0.86~0.92 is met, and the sealing effect is good under this fit, which is achieved by detecting the amount of gas at the inlet end of the inlet pipe.

[0079] In this embodiment, the length of the outlet pipe body is 180mm.

[0080] like Figure 3 As shown, the distance L2 between the top of the arc tube 204 and the mathematical axis of the inlet tube body 101 is 47.43 mm, satisfying L2>D. 球 , and L2:D 球 =47.43:28, which satisfies the requirement of (42~50):(25~30).

[0081] likeFigure 5 As shown, the bottom of the arc pipe inlet end 202 and the outlet pipe connection end 302 is a rounded chamfer structure, forming a rounded chamfer 321 at the bottom of the arc pipe inlet end and the outlet pipe connection end.

[0082] Example 2 The other settings in this embodiment are the same as in embodiment 1, with the following differences: Figure 4 and Figure 9 As shown, the inlet end 402 of the waste discharge pipe has a downwardly curved chamfer at the junction with the outlet pipe body 301. This causes the inlet end 402 of the waste discharge pipe to move downward as a whole, making it easier for dirt to move into the waste discharge pipe.

[0083] This implementation example Figure 4 As shown, the distance L1 between the mathematical axis line at the top of the arc pipe 204 and the mathematical axis line 404 of the waste discharge pipe body is 0, meaning they coincide. The inner diameter D of the waste discharge pipe body in this embodiment... 杂 The diameter is 8mm. It satisfies 0 ≤ L1 < 0.15D. 杂 Requirements.

[0084] As a further description, a specific implementation process of the blast furnace pulverized coal injection safety shut-off device described in Example 1 or Example 2 is shown, including the following steps: (1) The blast furnace pulverized coal injection safety shut-off device of Example 1 or Example 2 is cast by integral casting.

[0085] (2) The blast furnace pulverized coal injection safety shut-off device obtained by integral casting in step (1) is connected to the outlet of the pulverized coal injection system (e.g., the injection branch pipe) through the inlet end 102 of the inlet pipe 100, and the outlet end 303 of the outlet pipe 300 is connected to the pulverized coal injection gun set at the pulverized coal injection port of the blast furnace. The whole device is installed on the blast furnace; the shut-off ball 500 is installed through the top end 204 of the arc pipe of the shut-off bend 200 and the sealing cover 206 is tightened.

[0086] (3) The pulverized coal injection device is started to carry out pulverized coal injection in the blast furnace. The stop ball 500 is impacted by pulverized coal and airflow to the stop bend 200 near the top of the arc tube 204 and continues to rotate under continuous impact. Figure 5 As shown, the airflow inside the blast furnace pulverized coal injection safety shut-off device is also as follows: Figure 5 The flow is shown.

[0087] (4) When any component in the pulverized coal injection device malfunctions or loses power, the flow of pulverized coal and carrier gas in the blast furnace pulverized coal injection safety shut-off device decreases or disappears, the shut-off ball 500 falls to the bottom of the shut-off bend 200, the gas pressure inside the blast furnace is greater than the gas pressure of the pulverized coal and carrier gas flow, and the gas flow direction in the blast furnace pulverized coal injection safety shut-off device changes direction, such as... Figure 6As shown, the falling stop ball 500 is blown to the inlet pipe connection end 104 of the inlet pipe 100 to achieve a one-way seal, and due to the continuous presence of blast furnace gas pressure, the stop ball 500 continues to maintain close contact with the inlet pipe connection end 104 of the inlet pipe 100.

[0088] (5) After the pulverized coal injection device malfunction is resolved, the pulverized coal and carrier gas flow are discharged at high speed through the inlet pipe 100. The stop ball 500 is impacted by the pulverized coal and airflow and is pushed into the stop bend 200 near the top of the arc pipe 204, and continues to rotate under the continuous impact. Figure 5 The flow is shown.

[0089] (6) After the overall pulverized coal injection operation is completed, unscrew the sealing nut set at the outlet end 403 of the waste discharge pipe, insert the steel rod from bottom to top, and break the dirt deposited inside the pulverized coal injection safety shut-off device of the blast furnace. The dirt is discharged downward through the waste discharge pipe 400. Then tighten the sealing nut at the outlet end 403 of the waste discharge pipe.

[0090] Comparative Example 1 The other settings in this comparative example are the same as in Example 2, except that the inner diameter D of the outlet pipe body 301 is different. 出 Setting the diameter to 26mm allows the outlet pipe to more easily align with subsequent components, as described in the background art document. Comparative tests were conducted using this scaled-down device. During the tests, irregular collision sounds were continuously heard between the stop ball and the inner wall of the arc tube body. This indicates that the stop ball does not remain dynamically in a fixed position within the stop bend, but rather experiences irregular collisions with the inner wall of the arc tube body. This is due to the "diameter change" between the inlet and outlet pipes, which generates excessive turbulence in the airflow as it passes through the arc tube body, causing the stop ball to wobble. Such irregular collisions lead to increased losses at relatively high temperatures and pose safety hazards under extreme conditions.

[0091] Comparative Example 2 The other settings in this comparative example are the same as in Example 2, except that the components are formed by welding rather than by integral casting. A comparative test was conducted using the device in this example. After running for 36 hours, the device was disassembled, and it was found that the inlet pipe connection end, the arc pipe side end, and the discharge pipe inlet end all showed a certain degree of erosion wear. In contrast, after disassembling the device of Example 2, which had run for 36 hours, virtually no erosion wear was observed.

[0092] Comparative Example 3 The other settings in this comparative example are the same as in Example 2, except that the mathematical axis of the pipe at the top of the arc pipe does not coincide with the mathematical axis of the main body of the discharge pipe. Instead, it is set closer to the inlet pipe, and the distance between the mathematical axis of the pipe at the top of the arc pipe and the mathematical axis of the main body of the discharge pipe is set to 8mm, which does not satisfy 0≤L1<0.15D. 杂 The requirements are that it should be close to the inlet pipe. A comparative test was conducted using this device. After running for 36 hours, the device was disassembled and it was found that severe erosion wear occurred at the inlet end of the discharge pipe. This is because the discharge pipe is located below the stop bend and close to the inlet pipe. At this location, the airflow diameter increases as it exits from the inlet pipe to the stop bend, causing vortex development. Since the inlet end of the discharge pipe is a downward channel, the airflow easily becomes further turbulent, thus further intensifying the impact on both sides of the discharge pipe inlet end. In contrast, in Embodiments 1 and 2 of this invention, the discharge pipe is located below the stop bend and close to the outlet pipe. Because the inner diameter of the outlet pipe is the same as that of the inlet pipe, the airflow has already entered the outlet bend after passing through the stop bend. Since the inlet and outlet inner diameters are the same, the airflow velocity and disturbance at this location are relatively small. Furthermore, because the junction of the stop bend and the outlet pipe is a gradually narrowing arc, the airflow... Figure 5 As shown, the airflow is curved upwards, so the airflow at the inlet of the waste discharge pipe is obliquely upwards, thus preventing scouring and wear at the inlet of the waste discharge pipe. This also proves that the specific setting and limitation of the present invention have outstanding substantive features.

[0093] Comparative Example 4 The other settings in this comparative example are the same as in Example 2, except that the diameter D of the stop sphere is different. 球 The value is 31mm, which does not satisfy D. 弧 :D 球 :D 入 The requirement of (30~34): (26~29): (22~25) necessitates a relatively large diameter of the stop ball. A comparative test was conducted using this device. After 36 hours of operation, the device was disassembled, revealing some wear on the stop ball. This indicates that the stop ball experiences significant friction against the inner wall of the stop bend during rotation. Excessive friction increases the likelihood of uncontrollable buoyancy in the airflow, negatively impacting the overall stability of the device. Analysis of the disassembled device from Example 2, which had run for 36 hours, revealed virtually no wear on the stop ball, demonstrating that the diameter ratio set in this invention ensures the stability of the stop ball during airflow rotation and floating.

[0094] Comparative Example 5 The other settings in this comparative example are the same as in Example 2, except that the mass of the stop ball is 0.098 kg (using a stainless steel ball), then M 球 / V 煤 ≈0.2, does not meet 0.052V 煤 <M 球 <0.19V 煤 To meet the requirements, a comparative test was conducted using this proportional device. During operation, it was found that the airflow discharged from the outlet pipe was unstable, fluctuating in intensity. The analysis revealed that the cause was that the mass of the stop ball was too large, resulting in unstable suspension and a low position. Consequently, it tended to linger in the horizontal region within the stop bend, causing internal airflow instability.

[0095] The techniques known in the art involved in this invention have not been described in detail. The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A blast furnace pulverized coal injection safety shut-off device, characterized in that, It includes a stop ball and an integrally cast inlet pipe, stop bend, outlet pipe and waste discharge pipe; The inlet pipe includes an inlet pipe body, an inlet end, a valve seat, and an inlet pipe connection end; The cut-off bend includes an arc tube body, an arc tube inlet end, an arc tube side end, and an arc tube top end; The outlet pipeline includes an outlet pipe body, an outlet pipe connection end, and an outlet end; The waste discharge pipe includes a waste discharge pipe body, a waste discharge pipe inlet end, and a waste discharge pipe outlet end; The inlet end of the inlet pipe is connected to the outlet of the pulverized coal injection system, and the inlet pipe connection end is connected to the inlet end of the arc pipe. The arc pipe body is set as an arc-shaped pipe with an opening on the side, the arc pipe side opening is set opposite to the arc pipe inlet, and the mathematical axis of the arc pipe side opening is parallel or coincident with the mathematical axis of the inlet pipe body. The arc pipe side opening is connected to the outlet pipe connection end, and the top of the arc pipe is set with a cap. The outlet end of the outlet pipe is connected to the inlet of the pulverized coal injection gun. The main body of the waste discharge pipe is vertically opened on the bottom wall of the main body of the outlet pipe. The inlet end of the waste discharge pipe is connected to the inside of the outlet pipe. The mathematical axis of the pipe at the top of the arc pipe is parallel to the mathematical axis of the main body of the waste discharge pipe. The stop sphere is located inside the arc tube body, and the diameter of the stop sphere is D. 球 The inner diameter of the arc tube body is D. 弧 The inner diameter of the inlet pipe body is D. 入 The inner diameter of the outlet pipe body is D. 出 Satisfying D 入 =D 出 And D 弧 :D 球 :D 入 =(30~34):(26~29):(22~25) The distance between the mathematical axis of the pipe at the top of the arc pipe and the mathematical axis of the main body of the waste discharge pipe is L1, and the inner diameter of the main body of the waste discharge pipe is D. 杂 The condition 0 ≤ L1 < 0.15D is satisfied. 杂 ; The mass of the stopping ball is M 球 The flow rate of pulverized coal discharged into the inlet pipe is V. 煤 It meets the requirement of 0.052V. 煤 < M 球 <0.19V 煤 M 球 The unit is kg, V 煤 Unit: kg / s.

2. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, The mathematical axis of the arc tube body is a 1 / 4 arc segment, and the radius of the inner arc segment of the arc tube body is R. 内 The radius of the outer arc segment of the arc tube body is R. 外 Satisfying R 外 / R 内 = (68~75): (26~30).

3. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, The mathematical axis of the outlet pipe body coincides with the mathematical axis of the inlet pipe body, or the distance between the mathematical axis of the outlet pipe body and the mathematical axis of the inlet pipe body is less than or equal to 3 mm.

4. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, External threads are provided on the outer wall of the outlet end of the waste discharge pipe, and a sealing nut is provided at the outlet end of the waste discharge pipe; The inlet end of the discharge pipe is provided with a downward arc-shaped chamfer at the junction with the outlet pipe body; The bottom of the connection between the inlet and outlet pipes of the arc pipe is designed with a rounded chamfer.

5. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, The stop ball is a silicon nitride ceramic ball, a zirconia ceramic ball, or a steel ball.

6. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, A chamfer is provided at the inlet pipe connection end. In the closed state, the stop ball contacts the chamfer to achieve a seal. The contact point between the stop ball and the chamfer forms a circular line with a diameter of D. 密封 Satisfying D 密封 / D 球 =0.86~0.

92.

7. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, The length of the outlet pipe body is greater than or equal to 100 mm.

8. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, A axial step is provided on both the inlet pipe body and the outer wall of the inlet end of the inlet pipe; A axial step is provided on the outer wall of the outlet pipe body of the outlet pipe; The inlet pipe, stop bend, outlet pipe, and waste discharge pipe are all open. The inner walls of the inlet pipe, stop bend, outlet pipe, and waste discharge pipe are coated with a wear-resistant coating of tungsten carbide, silicon nitride, and / or zirconium oxide, with a thickness of 20~50µm.

9. The blast furnace pulverized coal injection safety shut-off device according to claim 1, characterized in that, The distance L2 between the top of the arc tube and the mathematical axis of the inlet tube body satisfies L2 > D. 球 , and L2:D 球 = (42~50): (25~30).

10. A method for safely shutting off pulverized coal injection in a blast furnace, characterized in that, The method uses the blast furnace pulverized coal injection safety shut-off device according to any one of claims 1 to 9, and includes the following steps: (1) The blast furnace pulverized coal injection safety shut-off device according to any one of claims 1 to 9 is cast by integral casting; (2) Connect the blast furnace pulverized coal injection safety shut-off device obtained by integral casting in step (1) to the outlet of the pulverized coal injection system through the inlet end of the inlet pipe and the outlet end of the outlet pipe to the inlet of the pulverized coal injection gun. The whole device is installed on the blast furnace; the shut-off ball is installed through the top of the arc tube of the shut-off bend and the cover is tightened. (3) Start the pulverized coal injection device to carry out pulverized coal injection in the blast furnace. The stop ball is impacted by pulverized coal and airflow to the stop bend and close to the top of the arc tube, and continues to rotate under continuous impact. (4) When any component in the pulverized coal injection device malfunctions or loses power, the flow of pulverized coal and carrier gas in the blast furnace pulverized coal injection safety shut-off device decreases or disappears, the shut-off ball falls to the bottom of the shut-off bend, the gas pressure inside the blast furnace is greater than the gas pressure of the pulverized coal and carrier gas flow, the gas flow direction inside the blast furnace pulverized coal injection safety shut-off device changes direction, the fallen shut-off ball is blown to the inlet pipe connection end of the inlet pipe to achieve one-way sealing, and due to the continuous existence of blast furnace gas pressure, the shut-off ball continues to maintain close contact with the inlet pipe connection end of the inlet pipe. (5) When the pulverized coal injection device is cleared, the pulverized coal and carrier gas flow are discharged at high speed through the inlet pipe. The stop ball is impacted by the pulverized coal and air flow to the stop bend and close to the top of the arc tube, and continues to rotate under the continuous impact. (6) After the overall pulverized coal injection operation is completed, unscrew the sealing nut at the outlet end of the discharge pipe, insert the steel rod from bottom to top, and break the scale deposited inside the pulverized coal injection safety shut-off device of the blast furnace. The scale is discharged downward through the discharge pipe, and then tighten the sealing nut at the outlet end of the discharge pipe.

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