A high-temperature powder feeding device, method and metallurgical production line

Abstract

The present invention relates to a high-temperature powder feeding device, method and metallurgical production line, comprising a double-screw conveyor, wherein the feeding end of the double-screw conveyor is provided with a hot fluid inlet, the discharging end of the double-screw conveyor extends into the grinding chamber of an air flow pulverizer, and the discharging end of the double-screw conveyor has an upwardly inclined anti-gas cross-talk section, an inverted cone-shaped screen is provided inside the grinding chamber, the screen is located below the discharging end of the double-screw conveyor, a drop hole is provided at the center of the screen, the grinding chamber part below the screen is connected to an air supply pipe, and the grinding chamber part above the screen is provided with a discharge port. The feeding device of the present invention can ensure the smooth transportation of high-temperature powdered coke materials.

Description

Technical Field

[0001] The present invention relates to the technical field of material feeding, and in particular to a high-temperature powder feeding device, method and metallurgical production line. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Continuous conveying equipment is widely used in chemical, coal, food, metallurgy, electric power, mechanical processing and other industries to realize the conveying, lifting, mixing, mixing, metering, heating, cooling, drying and other similar operations of powdered or granular materials, including materials with high viscosity and compressibility. However, during the conveying of high-temperature materials (above 500°C), especially coke fuel or raw materials, the temperature and humidity of the materials and the spiral wall and screw may be greatly different due to the start-stop or discontinuous conveying process, which may lead to softening and decomposition, and then cause scaling, slagging and agglomeration and other "blockages", resulting in supply failures, which is the biggest hidden danger and operational difficulty in the conveying process of high-temperature powdered materials. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a high-temperature powder feeding device to avoid the scaling, slagging and agglomeration problems of the high-temperature powder during the transportation process.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions

[0006] In the first aspect, an embodiment of the present invention provides a high-temperature powder feeding device, including a double-screw conveyor, a feed end of the double-screw conveyor is provided with a hot fluid inlet, the discharge end of the double-screw conveyor extends into the grinding chamber of the air flow pulverizer, and the discharge end of the double-screw conveyor has an upwardly inclined anti-gas cross-talk section, an inverted cone-shaped screen is provided inside the grinding chamber, the screen is located below the discharge end of the double-screw conveyor, a drop hole is provided in the center of the screen, the grinding chamber wall below the screen is connected to an air supply pipe, and the grinding chamber wall above the screen is provided with a discharge port.

[0007] Optionally, the twin screw conveyor adopts a shaftless twin screw conveyor.

[0008] Optionally, along the material flow direction, the pitch of the spiral blades of the double screw conveyor gradually decreases.

[0009] Optionally, the angle between the anti-cross-flow section and the horizontal plane is 15°-35°.

[0010] Optionally, a plurality of air inlets are provided on the cavity wall of the pulverizing cavity, each of the air inlets is connected to the air supply pipe, the plurality of air inlets are arranged circumferentially along the outer shell, and the axes of the plurality of air inlets intersect with a point located on the axis of the drop hole.

[0011] Optionally, the feed pipe of the double screw conveyor is connected to an ash hopper, and a first switch valve is provided at the bottom outlet of the ash hopper. The first switch valve is connected to the feed pipe of the double screw conveyor through a first flexible connection expansion joint. The ash hopper is connected to a first weighing device and supported by the first weighing device.

[0012] Optionally, a slag discharge port is provided at the bottom of the crushing chamber, a second switch valve is installed at the slag discharge port, the second switch valve is connected to the feed port of the slag tank through a second flexible expansion joint, the air flow crusher is connected to a second weighing device, and is supported by the second weighing device.

[0013] Optionally, a third switch valve is provided at the bottom discharge port of the slag tank.

[0014] In the second aspect, an embodiment of the present invention provides a working method of a high-temperature powder feeding device, in which a double-screw conveyor performs preliminary crushing on the fed material and feeds the material into an anti-gas section. After the material is accumulated in the anti-gas section, the discharge end of the double-screw conveyor is blocked. The material in the anti-gas section falls into the screen under the squeezing action of the material behind and falls from the drop hole. The material is further crushed by gas of a set pressure fed into the air supply pipe. After crushing, the material with a particle size smaller than the set value passes through the screen under the action of the airflow and flows out from the discharge port, and the material with a particle size larger than the set value accumulates at the bottom of the crushing chamber.

[0015] In a third aspect, an embodiment of the present invention provides a metallurgical production line provided with the high-temperature powder coke supply device described in the first aspect.

[0016] Beneficial effects of the present invention:

[0017] 1. The feeding device of the present invention has a double-screw conveyor and a gas crushing chamber. The double-screw conveyor can be used to perform preliminary crushing on the material, and the gas with a set pressure introduced into the gas crushing chamber can be used to further crush the material. After a sufficient fluidized gas-solid two-phase flow is formed, only the material that meets the particle size requirements can pass through the screen and flow out from the discharge port to enter the next process. The particle size of the output material is smaller than the set value, which ensures a good pneumatic conveying effect and avoids clogging of subsequent conveying pipelines, ensuring the normal material conveying. It can effectively adapt to changes in the layout of the conveying pipeline and the appearance of elbows, and the safety and reliability of the material supply system are significantly improved. In addition, by adopting gas crushing, the gas source within the factory area can be used, which reduces the cost.

[0018] 2. In the feeding device of the present invention, the feeding section of the double-screw conveyor has a hot fluid inlet, which can pass hot fluid, and the double-screw conveyor adopts a shaftless double-screw conveyor. The hot fluid can effectively prevent the coke powder particulate material from adhering, scaling and slagging on the screw sheets, and the screw-free design reduces the temperature difference of components, improves reliability and reduces the area of ​​scaling and slagging.

[0019] 3. In the feeding device of the present invention, the discharge end of the double screw conveyor is provided with an anti-gas cross-contamination section, which can allow the material to accumulate in the anti-gas cross-contamination section and seal the discharge end of the double screw conveyor, thereby preventing the gas in the crushing chamber from entering the double screw conveyor and affecting the normal operation of the double screw conveyor, so that the initial crushing of the double screw conveyor and the further crushing of the gas can be combined to improve the crushing effect.

[0020] 4. The feeding device of the present invention can weigh the weight of the ash hopper and the crushing chamber by means of the setting of the flexible connection expansion joint and the weighing device, so as to automatically discharge the slag from the crushing chamber by means of the comparison of the two weight values, so as to prevent the accumulation of large particles of material and scaling or slagging blockage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings in the specification, which constitute a part of the present application, are used to provide a further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute a limitation on the present application.

[0022] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0023] Among them, 1. ash hopper, 2. first gate valve, 3. first flexible connection expansion joint, 4. first weighing device, 5. driving motor, 6. spiral blade, 7. hot fluid inlet, 8. double screw conveyor, 9. anti-gas cross-flow section, 10. air flow mill, 11. grinding chamber, 12. flange, 13. screen, 14. air supply pipe, 15. discharge port, 16. second gate valve, 17. second flexible connection expansion joint, 18. second weighing device, 19. slag tank, 20. jaw electric slag discharge valve, 21. steel bracket, 22. control system. DETAILED DESCRIPTION

[0024] Example 1

[0025] This embodiment provides a high temperature powder feeding device, wherein the high temperature powder refers to powder with a temperature higher than 500°C. Figure 1 As shown, it includes a double screw conveyor 8. In this embodiment, the double screw conveyor 8 can be an existing double screw conveyor, which has the function of preliminarily crushing and conveying the incoming materials.

[0026] Specifically, the double screw conveyor 8 includes an outer shell, which is fixed on an external frame, one end of the outer shell serves as a feed end, and the other end serves as a discharge end. In this embodiment, the double screw conveyor adopts a shaftless double screw conveyor, having two spiral blades 6, and the two spiral blades 6 are both connected to a drive motor 5. The two drive motors 5 can drive the spiral blades 6 to move in the opposite direction. The two spiral blades 6 are staggered, and can crush and convey the incoming materials.

[0027] In another embodiment, one of the spiral blades 6 is connected to the drive motor 5 via a first connecting shaft, a first gear is provided on the first connecting shaft, the first gear is meshed with the second gear, the second gear is connected to the second connecting shaft, and the second connecting shaft is connected to another spiral blade 6. Since the first gear and the second gear rotate in opposite directions, the two spiral blades 6 rotate in opposite directions.

[0028] Along the conveying direction of the material, the pitch of the spiral blade 6 gradually decreases.

[0029] A shaftless double-screw conveyor is adopted. On the one hand, the two spiral blades 6 mesh well and can effectively crush the agglomerated high-temperature coke powder. At the same time, the large-pitch spiral blades 6 at the front can speed up the feeding speed of large-particle materials, while the small-pitch spiral blades 6 at the rear can effectively increase the thrust to ensure the conveying force of fine-particle materials. The shaftless setting of the screw conveyor can reduce the temperature difference of components, improve reliability and reduce the area of ​​scaling and slagging.

[0030] A hot fluid inlet 7 is provided at the feed end of the shell of the double-screw conveyor 8, and hot fluid can be injected into the interior of the shell through the hot fluid inlet 7. In this embodiment, the hot fluid is heat transfer oil. By injecting the heat transfer oil, it can effectively prevent the coke powder particulate material from adhering, scaling and slagging on the spiral blades.

[0031] A feeding pipe is provided at the feeding end of the double screw conveyor 8 , and the feeding pipe is connected to the ash hopper 1 .

[0032] In this embodiment, the ash hopper 1 adopts an inverted cone structure, and the bottom end of the ash hopper 1 has a discharge port, and a first switch valve is installed at the discharge port. In this embodiment, the first switch valve adopts a first gate valve 2, and the first gate valve 2 can control the opening and closing of the ash hopper 1 discharge port.

[0033] The first gate valve 2 is connected to one end of the first flexible connection expansion joint 3 , and the other end of the first flexible connection expansion joint 3 is connected to the feed pipe of the double screw conveyor 8 .

[0034] The ash hopper 1 is connected to the first weighing device 4, which can weigh the total weight of the ash hopper 1 and the material therein. In this embodiment, due to the setting of the first flexible connection expansion joint 3, the double screw conveyor 8 does not provide support force to the ash hopper, so the first weighing device 4 can detect the weight of the ash hopper 1 and the material therein.

[0035] In this embodiment, the first weighing device 4 is an existing automatic weighing device. The first weighing device is connected to the control system 22 and can transmit the detected weight information to the control system 22 .

[0036] The ash hopper 1 is connected to the ash hopper frame, and the ash hopper frame is placed on the first weighing device 4, and the first weighing device is used to support the ash hopper 1.

[0037] The shell of the double-screw conveyor 8 is fixed to the air flow pulverizer 10 by a flange 12 and fixing bolts. The air flow pulverizer 10 has a pulverizing chamber 11 inside. The air flow pulverizer 10 is arranged on one side of the double-screw conveyor 8. The discharge end of the double-screw conveyor 8 extends into the pulverizing chamber 11. The end of the double-screw conveyor 8 shell extending into the pulverizing chamber is provided with an anti-gas cross-talk section 9. The anti-gas cross-talk section 9 is inclined upward, that is, the height of the connecting end of the anti-gas cross-talk section 9 and the double-screw conveyor 8 shell is lower than the height of the other end.

[0038] The axis of the anti-gas cross-talk section 9 forms a set acute angle with the horizontal plane, and the set acute angle is 15°-35°. No spiral blades are arranged inside the anti-gas cross-talk section 9, and the length thereof is 50mm-100mm. The materials transported by the double-screw conveyor 8 can be accumulated in the anti-gas cross-talk section until the accumulated materials block the anti-gas cross-talk section 9. When the materials continue to be transported, the materials in front of the anti-gas cross-talk section 9 fall into the crushing chamber under the action of their own gravity under the squeezing action of the materials at the rear.

[0039] Since the material has been blocking the anti-gas section 9, the gas in the crushing chamber 11 will not enter the double screw conveyor 8, and will not affect the normal operation of the double screw conveyor 8, thereby realizing the combination of preliminary crushing of the double screw conveyor 8 and further crushing of the gas in the crushing chamber 11.

[0040] The pulverizing chamber 11 is a cylindrical cavity. A screen 13 is arranged inside the pulverizing chamber 11 . The screen 13 is an inverted cone structure, and its outer edge is fixed to the inner surface of the pulverizing chamber 11 .

[0041] The screen 13 has meshes for filtering, and a material drop hole is provided at the center of the screen 13. The diameter of the material drop hole is set according to actual needs to control the diameter of the material drop range. The angle between the conical surface of the screen 13 and the horizontal plane is consistent with the angle between the anti-gas section 9 and the horizontal plane, which is 15°-35°. The diameter-to-height ratio of the screen 13 is 10:1-5:1. By controlling the angle between the conical surface of the screen 13 and the horizontal plane and the diameter of the material drop hole, the initial velocity and diameter of the material drop can be controlled.

[0042] In this embodiment, the screen 13 divides the internal space of the crushing chamber into a first space and a second space arranged upper and lower. The discharge end of the double-bolt conveyor 8 and the anti-gas section 9 are located in the first space, that is, above the screen 13. The second space below the screen 13 is used as a space for pneumatic crushing.

[0043] The cavity wall of the crushing cavity 11 corresponding to the second space is connected with a plurality of air supply pipes 14, which can be connected to an air source. The air source can deliver gas of set pressure into the second space through the air supply pipes 14 to form a gas jet, which impacts, collides and rubs the material falling from the drop hole, thereby achieving pneumatic crushing.

[0044] In this embodiment, nitrogen is used as the gas, and the gas source can be the nitrogen source in the factory. There is no need to set up additional crushing power equipment, which reduces production costs.

[0045] In this embodiment, a plurality of air supply pipes 14 are arranged on the cavity wall of the crushing cavity 11. The air supply pipes 14 are evenly distributed in the circumferential direction of the circle where the crushing cavity is located. The plurality of air supply pipes 14 are connected to the air source through an air supply main pipe. The axes of the plurality of air supply pipes 14 intersect at one point, and the point is located on the axis of the drop hole. In this way, a centripetal jet flow field can be formed to achieve the best crushing effect.

[0046] A discharge port 15 is provided on the wall of the grinding chamber corresponding to the first space above the screen 13 for connecting to subsequent production equipment.

[0047] The fluidized material crushed by pneumatic force has a particle size smaller than the diameter of the mesh holes of the screen 13 , and passes through the screen under the action of the airflow and flows out from the discharge port 15 , while the material with a particle size larger than the diameter of the mesh holes of the screen 13 is deposited at the bottom of the crushing chamber 11 .

[0048] The device of this embodiment can use the double screw conveyor 8 to perform preliminary crushing on the material, and use the gas of set pressure introduced into the gas crushing chamber 11 to further crush the material, so that after forming a fully fluidized gas-solid two-phase flow, only the material that meets the particle size requirements can pass through the screen 13 and flow out from the discharge port 15 to enter the next process. The particle size of the output material is smaller than the set value, which ensures a good pneumatic conveying effect, avoids clogging of subsequent conveying pipelines, and ensures the normal progress of material conveying. It can effectively adapt to changes in the layout of the conveying pipeline and the appearance of elbows, and the safety and reliability of the material supply system are significantly improved.

[0049] The bottom of the crushing chamber 11 is an inverted cone structure, and a slag discharge port is arranged at the center of the bottom. A second switch valve is installed at the slag discharge port. The second switch valve adopts a second gate valve 16, and the second gate valve 16 can control the opening and closing of the slag discharge port.

[0050] The second gate valve 16 is connected to one end of the second flexible expansion joint 17 , and the other end of the second flexible expansion joint 17 is connected to the feed port of the slag tank 19 . When the second gate valve 16 is opened, the slag accumulated at the bottom of the pulverizing chamber 11 can be discharged into the slag tank 19 .

[0051] A discharge port is provided at the bottom end of the slag tank 19, and a third switch valve is installed at the discharge port. The third switch valve adopts a jaw-type electric slag discharge valve 20. The jaw-type electric slag discharge valve 20 is used to control the opening and closing of the discharge port at the bottom end of the slag tank 19. The slag tank 19 is fixed on a steel bracket 21 and supported by the steel bracket 21. After opening the jaw-type electric slag discharge valve 20, the slag in the slag tank 19 can be discharged, and the discharged large-particle slag is transported by the plant transfer vehicle to the initial unloading link for recycling.

[0052] In this embodiment, the air flow pulverizer 10 is connected to the second weighing device 18 and supported by the second weighing device 18. Since the second flexible connection expansion joint 17 is used, the slag tank 19 does not support the air flow pulverizer 10. Therefore, the second weighing device 18 can detect the total weight of the pulverizing chamber 11 and the material therein.

[0053] The second weighing device 18 can be an existing automatic weighing device, which is connected to the control system 22 and can transmit the collected weight information to the control system 22. The airflow pulverizer 10 can be placed on the second weighing device 18 through a bracket and supported by the second weighing device 18.

[0054] In this embodiment, the control system 22 adopts a PLC control system, and the PLC control system is also connected to the first gate valve 2, the second gate valve 16 and the jaw electric slag discharge valve 20, and can control the operation of the above three valves.

[0055] The PLC control system is also connected to the double screw conveyor 8 and can control the operation of the double screw conveyor 8 .

[0056] In this embodiment, the mass flow rate data is obtained by the first weighing device 4 and the second weighing device 18, and the PLC control system automatically performs diagnostic analysis. When the comparison data shows a large deviation (deviation of 10-15%), the PLC system diagnoses that the material is accumulated inside the crushing chamber, and automatically starts the second gate valve 16 and the jaw electric slag discharge valve 20 in sequence to start slag discharge, and discharges the remaining large particles of material from the system to prevent residual scaling or slag blockage.

[0057] Example 2

[0058] The present embodiment provides a working method of the high-temperature powder feeding device described in Embodiment 1: the high-temperature powder is high-temperature coke powder, the first gate valve 2 is opened, and the independent powdered coke powder or slightly agglomerated powder in the ash hopper enters the double-screw conveyor 8, and the two spiral blades 6 of the double-screw conveyor 8 preliminarily crush the material to form fine-grained material, and convey the material. When conveyed to the anti-gas section 9, the material is accumulated until the anti-gas section 9 is completely blocked, and then under the squeezing action of the rear material, the material in the front of the anti-gas section 9 freely falls to the screen 13, and slides along the screen 13 through the drop hole and falls into the second space, and the material falling into the second space is further crushed under the action of the nitrogen jet fed by the air supply pipe 14. After forming a sufficient fluidized gas-solid two-phase flow, the suspended material with a particle size smaller than the diameter of the screen hole of the screen 13 after crushing passes through the screen and flows out to the next process equipment through the discharge port 15 under the action of the airflow, and the material with a particle size larger than the diameter of the screen hole of the screen 13 accumulates at the bottom of the crushing chamber 11.

[0059] The first weighing device 4 and the second weighing device 18 detect the weight of the ash hopper 1 and the air flow pulverizer 10 and the materials therein in real time and compare them. When the comparison data shows a large deviation (deviation of 10-15%), the PLC system diagnoses the internal material accumulation and automatically starts the second gate valve 16 and the jaw electric slag discharge valve 20 in sequence to start slag discharge. The discharged large-particle slag is transported by the plant transfer vehicle to the initial unloading link for recycling.

[0060] The device of this embodiment solves the problem of conventional spiral material supply systems. High-temperature coke raw materials are prone to various blockage risks on the spiral blades, spiral shaft and spiral outer wall due to temperature differences and humidity changes. The coke raw materials are initially crushed and further pulverized to ensure a good pneumatic conveying effect. It can effectively adapt to changes in the layout of the conveying pipeline and the appearance of elbows, and the safety and reliability of the material supply system are significantly improved.

[0061] Example 3

[0062] This embodiment provides a metallurgical production line, which is provided with the high-temperature powder feeding device described in Embodiment 1. Other equipment of the production line can adopt existing equipment and will not be described in detail here.

[0063] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A high temperature powder feeding device, characterized in that: It includes a double-screw conveyor, the feed end of the double-screw conveyor is provided with a hot fluid inlet, and the hot fluid can be injected into the shell through the hot fluid inlet, which can effectively prevent the coke powder particulate material from adhering, scaling and slagging on the spiral blades, the discharge end of the double-screw conveyor extends into the grinding chamber of the air flow mill, and the discharge end of the double-screw conveyor has an upwardly inclined anti-gas cross-talk section, an inverted cone-shaped screen is provided inside the grinding chamber, the screen is located below the discharge end of the double-screw conveyor, a drop hole is provided in the center of the screen, the grinding chamber wall below the screen is connected to an air supply pipe, and the grinding chamber wall above the screen is provided with a discharge port; The double screw conveyor adopts a shaftless double screw conveyor. Along the material flow direction, the pitch of the spiral blades of the double screw conveyor gradually decreases. The screwless design reduces the temperature difference of the components, improves reliability and reduces the area of ​​scaling and slagging. The angle between the anti-gas cross-talk section and the horizontal plane is 15°-35°, and no spiral blades are arranged inside the anti-gas cross-talk section. The materials transported by the double-screw conveyor can accumulate in the anti-gas cross-talk section until the accumulated materials block the anti-gas cross-talk section. The gas in the crushing chamber will not enter the double-screw conveyor. When the materials continue to be transported, the materials in front of the anti-gas cross-talk section fall into the crushing chamber under the action of their own gravity under the squeezing action of the materials at the rear.

2. A high temperature powder feeding device as claimed in claim 1, characterized in that: A plurality of air inlets are arranged on the wall of the pulverizing chamber, each of which is connected to an air supply pipe. The plurality of air inlets are arranged circumferentially along the shell, and the axes of the plurality of air inlets intersect with a point located on the axis of the blanking hole.

3. A high temperature powder feeding device as claimed in claim 1, characterized in that: The feed pipe of the double screw conveyor is connected to an ash hopper, and a first switch valve is provided at the bottom outlet of the ash hopper. The first switch valve is connected to the feed pipe of the double screw conveyor through a first flexible connection expansion joint. The ash hopper is connected to a first weighing device and supported by the first weighing device.

4. A high temperature powder feeding device as claimed in claim 3, characterized in that: A slag discharge port is provided at the bottom of the pulverizing chamber, and a second switch valve is installed at the slag discharge port. The second switch valve is connected to the feed port of the slag tank through a second flexible expansion joint. The air flow pulverizer is connected to a second weighing device and supported by the second weighing device.

5. A high temperature powder feeding device as claimed in claim 4, characterized in that: A third switch valve is arranged at the bottom discharge port of the slag tank.

6. A method for operating the high temperature powder feeding device according to any one of claims 1 to 5, characterized in that: The double-screw conveyor performs preliminary crushing on the input material and sends the material to the anti-gas section. After the material is accumulated in the anti-gas section, the discharge end of the double-screw conveyor is blocked. The material in the anti-gas section falls into the screen under the extrusion of the material at the rear and falls from the drop hole. The gas of set pressure sent by the air supply pipe further crushes the material. After crushing, the material with a particle size smaller than the set value passes through the screen under the action of the airflow and flows out from the discharge port, and the material with a particle size larger than the set value accumulates at the bottom of the crushing chamber.

7. A metallurgical production line, characterized in that: A high-temperature powder feeding device as described in any one of claims 1 to 5 is provided.

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