Integrated measurement and control wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection into blast furnace

Abstract

The utility model belongs to blast furnace coal injection control valve field discloses a control integration wear -resisting corrosion -resisting valve for blast furnace coal injection uniform regulation and control. The utility model's ball surface is polished by mirror surface, so the surface is extremely smooth and erosion -resistant. When the valve is opened and closed, the ball will rotate 90 DEG, and this rotation changes the flow direction and produces scraping effect, and small coal powder adhered to the surface is entrained into the main stream. At the same time, the hard coating avoids burr or step due to abrasion, and keeps low roughness for a long time, so as to reduce the opportunity of powder retention from the source. The flow channel of the utility model through the ball adopts full diameter, equal diameter structure, and the inlet and outlet use round chamfer, and the turning radius is not less than three times of the pipe diameter. This smooth transition can eliminate the pressure drop and dead angle caused by sharp expansion and contraction, ensure that the high-speed gas-solid two-phase flow always flows along the wall without vortex deposition, thereby reducing the probability of particle residence in local.

Description

Technical Field

[0001] This utility model belongs to the field of blast furnace pulverized coal injection control valves, specifically relating to a wear-resistant and corrosion-resistant integrated measurement and control valve for uniform regulation of pulverized coal injection in blast furnaces. Background Technology

[0002] Pulverized coal injection (PCI) is a core component in blast furnace ironmaking, aimed at reducing the coke ratio and optimizing smelting efficiency. Traditional PCI systems rely on branch pipes to deliver pulverized coal to various tuyeres. However, due to a lack of effective control mechanisms, the distribution of pulverized coal in these branch pipes is often uneven, leading to significant differences in the amount of coal injected at each tuyer, which in turn causes combustion imbalances and furnace temperature fluctuations. Furthermore, valves, as critical control components in the PCI system, face the dual challenges of corrosion resistance and erosion resistance. Corrosion-resistant metal spheres have poor wear resistance and their coatings are easily damaged; ceramic spheres lack toughness, are brittle, and are costly. Simultaneously, when injecting pulverized coal or other powdery fluids, the internal flow channels of the valves are prone to blockage due to particle accumulation, severely affecting the normal delivery and injection efficiency of the pulverized coal. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the above-mentioned valve internal flow channel which is easily blocked by particle accumulation, and to provide a wear-resistant and corrosion-resistant valve with integrated measurement and control for uniform regulation of pulverized coal injection in blast furnace.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] This utility model provides a wear-resistant and corrosion-resistant integrated measurement and control valve for uniform regulation of pulverized coal injection in blast furnaces, including a valve body, a valve seat inside the valve body, a ball inside the valve seat, a flow channel on the ball, a through hole on the top of the valve seat, a valve stem passing through the through hole and connected to the ball, and an electric actuator connected to the valve stem. The surface roughness Ra of the ball is ≤0.4μm.

[0006] A further improvement of this invention is that the angle between the trajectory of the sphere and the axis of the flow channel is ≤15°.

[0007] A further improvement of this utility model is that the valve body is made of ZG40Cr25Ni20 heat-resistant cast steel.

[0008] A further improvement of this invention is that the valve body is covered with a tungsten carbide coating.

[0009] A further improvement of this utility model is that a stepped guide groove is provided on the inner wall of the valve body, and the inclination angle of the stepped guide groove is ≤30°.

[0010] A further improvement of this invention is that the sphere is made of silicon nitride.

[0011] A further improvement of this invention is the sealing arrangement between the valve stem and the valve body.

[0012] A further improvement of this utility model is that a pressure transmitter, a temperature transmitter, and a flow transmitter are provided at the upstream position of the valve body, and the pressure transmitter, temperature transmitter, and flow transmitter are all connected to an electric actuator.

[0013] A further improvement of this invention is that an inner liner is provided inside the flow channel of the sphere, and the openings at both ends of the inner liner have different shapes.

[0014] A further improvement of this utility model is that the valve body is connected to the pulverized coal injection branch pipe.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] The spherical surface of this invention is mirror-polished, resulting in an extremely smooth and erosion-resistant surface. During valve opening and closing, the spherical surface rotates 90°, altering the flow direction and creating a scraping effect that carries fine coal dust adhering to the surface into the main flow. Simultaneously, the hard coating prevents burrs or steps caused by wear, maintaining low roughness over the long term and reducing the chance of dust retention at the source. The flow channel penetrating the spherical surface employs a full-bore, uniform-diameter structure, with rounded corners at both the inlet and outlet, and a turning radius no less than three times the pipe diameter. This smooth transition eliminates pressure drop and dead zones caused by abrupt expansion and contraction, ensuring that the high-speed gas-solid two-phase flow remains flush with the wall without eddy deposition, thus reducing the probability of particles lingering locally. In conclusion, this invention, with its ultra-smooth and wear-resistant spherical surface and smooth flow channel, endows the valve with self-cleaning properties, enabling it to maintain unobstructed flow in blast furnace environments containing solid particles for extended periods, significantly reducing maintenance frequency and ensuring stable and uniform coal dust injection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is a schematic diagram of the inner lining of the sphere in this utility model;

[0019] 1. Valve cover; 2. Bolt; 3. Nut; 4. Valve body; 5. Valve seat; 6. Ball; 7. O-ring; 8. Packing; 9. Valve stem; 10. Packing gland; 11. Hex bolt; 12. Electric actuator; 13. Flange; 14. Pressure transmitter; 15. Temperature transmitter; 16. Flow transmitter. Detailed Implementation

[0020] To further understand the present invention, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are merely illustrative and not intended to limit the scope of the invention.

[0021] See Figure 1 A wear-resistant and corrosion-resistant integrated measurement and control valve for uniform regulation of pulverized coal injection in blast furnace includes a valve body 4, a valve seat 5 inside the valve body 4, a ball 6 inside the valve seat 5, a flow channel on the ball 6, a through hole on the top of the valve seat 5, a valve stem 9 passing through the through hole and connected to the ball 6, and an electric actuator 12 connected to the valve stem 9. The surface roughness Ra of the ball 6 is ≤0.4μm.

[0022] The valve body 4 is equipped with standard flanges 13 at both ends. The flanges 13 are sealed to the valve body 4 by O-rings 7 and are firmly connected to the pulverized coal injection branch pipe by bolts 2 and hex bolts 11, ensuring the sealing and stability of the installation. The wear-resistant valve body 4 is cast from ZG40Cr25Ni20 heat-resistant cast steel, ensuring structural stability and durability in high-temperature environments. The outer surface of the valve body 4 is coated with a tungsten carbide (WC-Co) coating with a thickness of ≥0.3mm using plasma spraying technology. The coating hardness reaches ≥1100HV, effectively resisting the high-speed erosion of pulverized coal particles. The inner wall flow channel of the valve body 4 is optimized and has stepped guide grooves. The inclination angle of the guide grooves is controlled at ≤30°, which guides the pulverized coal to flow along a specific trajectory, significantly reducing local wear caused by direct impact. A ball 6 is embedded inside the valve body 4. The ball 6 is connected to the electric actuator 12 installed on the top through a wear-resistant valve stem 9. The electric actuator drives the dynamic adjustment of the pulverized coal flow rate.

[0023] The ball 6 is housed within the internal flow channel of the wear-resistant valve body 4, employing a modular, split design with a streamlined overall shape to reduce resistance during pulverized coal flow. The ball 6 is a silicon nitride ceramic wear-resistant head with a surface roughness Ra≤0.4μm. Its high hardness and low coefficient of friction ensure long-term durability in pulverized coal scouring environments. The angle between the ball 6's movement trajectory and the flow channel axis is controlled to ≤15°, effectively reducing wear from lateral shear forces. The ball is mechanically connected to the electric actuator 12 via the wear-resistant valve stem 9. The valve stem 9 passes through the sealing structure inside the valve body 4 and fits tightly with the valve seat 5, forming an adjustable flow channel structure. The ball rotates around the valve stem 9, adjusting its relative position with the valve seat 5 to achieve precise control of the pulverized coal flow rate. Thanks to the application of the ceramic wear-resistant head, the ball maintains structural integrity and adjustment accuracy even under harsh operating conditions, ensuring the long-term stable operation of the device.

[0024] The sealing structure is located inside the valve body 4, arranged around the valve stem 9, and adopts a non-contact labyrinth seal design. It consists of multiple annular gaps, forming a turbulence barrier that effectively prevents coal dust particles from entering the valve stem cavity. In addition, the sealing structure is equipped with auxiliary sealing components, using a combination of flexible graphite and metal bellows, with a temperature resistance up to 400℃, further improving sealing reliability in high-temperature environments. The auxiliary seal is installed around the valve stem 9 and fits tightly against the inner wall of the valve body 4, ensuring a good seal while reducing frictional resistance. This dual-seal design not only prevents the valve stem 9 from jamming or wearing due to coal dust intrusion, but also significantly extends the maintenance cycle of the device and improves overall operational reliability. The multiple annular gaps are sealed by packing 8, which is equipped with a packing gland 10.

[0025] The valve opening limiting module is integrated into the bottom of the electric actuator 12 and includes an adjustable mechanical stop. This block-shaped stop is bolted to the inside of the valve body 4 and limits the maximum and minimum stroke of the ball, ensuring a minimum valve opening of ≥50%. The thread lead of the valve stem 9 is precisely optimized to achieve a proportional displacement-flow characteristic for the ball within the 65%-95% opening range. The mechanical stop effectively prevents the valve from completely closing, avoiding blockage caused by coal powder deposition at low flow rates. Simultaneously, the linear adjustment design ensures that the flow linearity error is controlled within ±1.5% within the 65%-95% opening range, meeting the high requirements for precise flow control in blast furnace pulverized coal injection systems.

[0026] The high-precision measurement module consists of a flow transmitter 16, a pressure transmitter 14, and a temperature transmitter 15, used to sense various key parameters of pulverized coal flow in real time. The flow transmitter 16 is installed at the measurement port upstream of the valve body 4 to ensure comprehensive monitoring of the pulverized coal flow rate. The flow transmitter 16 employs a dual-channel AC charge sensor, utilizing the charge characteristics generated by the friction of pulverized coal particles to measure flow velocity and concentration. Its flow velocity measurement range is 5-40 m / s, and its concentration measurement range is 0-50 t / h, with an accuracy of ±2%.

[0027] Pressure transmitter 14 and temperature transmitter 15 are cylindrical in structure. Pressure transmitter 14 is equipped with a high-temperature resistant ceramic diaphragm, with a range of 0-1.6MPa and an output of a 4-20mA standard signal. Temperature monitoring uses a type K thermocouple with a range of 0-600℃ and an IP67 protection rating. These two monitoring modules are also installed upstream of valve body 4, transmitting the measurement signal to the controller via a high-temperature wire. This provides accurate input data for the control system, supporting rapid response (response time ≤ 0.5 seconds) and high accuracy in flow regulation.

[0028] The electric actuator 12 is mounted on top of the valve body 4 and employs a high-performance electric regulating valve design. It features a built-in 18-bit absolute encoder with an opening resolution of ≤0.05%. The electric actuator 12 is mechanically connected to the ball via the valve stem 9, receiving commands from the embedded controller to drive the ball to move axially, precisely controlling the ball's opening and thus achieving dynamic regulation of the pulverized coal flow. The flow characteristic curve of the electric actuator has been corrected to adopt an equal percentage characteristic, ensuring near-linear regulation within the 65%-95% opening range. The application of the high-resolution encoder further improves the regulation accuracy, enabling the device to meet the highly dynamic flow control requirements of the blast furnace pulverized coal injection system.

[0029] The valve body 4 is cast from ZG40Cr25Ni20 heat-resistant cast steel, ensuring structural stability and durability in high-temperature environments. The outer surface of the valve body 4 is coated with a tungsten carbide (WC-Co) coating with a thickness ≥0.3mm using plasma spraying technology. The coating hardness reaches ≥1100HV, effectively resisting the high-speed erosion of coal dust particles. The ball 6 is a silicon nitride ceramic wear-resistant head with a surface roughness Ra≤0.4μm. Its high hardness and low coefficient of friction ensure long-term durability in coal dust erosion environments. The valve stem 9 employs a double seal, which not only prevents jamming or wear due to coal dust intrusion but also significantly extends the maintenance cycle of the device, improving overall operational reliability.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it. Although the utility model has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of this utility model. Any modifications or equivalent substitutions that do not depart from the spirit and scope of this utility model should be covered within the protection scope of the claims of this utility model.

Claims

1. A wear-resistant and corrosion-resistant integrated measurement and control valve for uniform regulation of pulverized coal injection in blast furnaces, characterized in that, The valve body (4) includes a valve seat (5) inside the valve body (4), a ball (6) inside the valve seat (5), a flow channel on the ball (6), a through hole on the top of the valve seat (5), a valve stem (9) passing through the through hole and connected to the ball (6), and the valve stem (9) is connected to an electric actuator (12). The surface roughness Ra of the ball (6) is ≤0.4μm.

2. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, The angle between the trajectory of the sphere (6) and the axis of the flow channel is ≤15°.

3. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, The valve body (4) is made of ZG40Cr25Ni20 heat-resistant cast steel.

4. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, The valve body (4) is covered with a tungsten carbide coating.

5. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in a blast furnace according to claim 1, characterized in that, The inner wall of the valve body (4) is provided with a stepped guide groove, and the inclination angle of the stepped guide groove is ≤30°.

6. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, The sphere (6) is made of silicon nitride.

7. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in a blast furnace according to claim 1, characterized in that, A sealing device is provided between the valve stem (9) and the valve body (4).

8. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, A pressure transmitter (14), a temperature transmitter (15), and a flow transmitter (16) are installed upstream of the valve body (4). The pressure transmitter (14), temperature transmitter (15), and flow transmitter (16) are all connected to an electric actuator (12).

9. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in blast furnaces according to claim 1, characterized in that, The flow channel of the sphere (6) is provided with an inner liner, and the openings at both ends of the inner liner have different shapes.

10. The integrated wear-resistant and corrosion-resistant valve for uniform regulation of pulverized coal injection in a blast furnace according to claim 1, characterized in that, The valve body (4) is connected to the coal injection branch pipe.

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