Pneumatic conveying system for hot direct reduction iron materials

Abstract

The utility model relates to the technical field of pneumatic conveying, in particular to a pneumatic conveying system for hot direct reduction iron materials. A conventional hot direct reduction iron pneumatic conveying system conveys HRDI materials into an electric arc furnace in a pneumatic mode, and the problems that equipment is prone to abrasion, and the materials are prone to breakage exist. In order to solve the problems, the utility model provides a hot direct reduction iron pneumatic conveying system, which comprises a hot direct reduction iron transmitter and a gas source valve group, the hot direct reduction iron transmitter consists of a transmitter upper part storage tank and a plug forming transmitter, and the plug forming transmitter adopts the special structural design of three inclined pipes. Under the condition that materials in the plug forming transmitter are not subjected to external force, the materials are not prone to sliding into a conveying pipeline, stable material plugs are formed in the three-inclined-pipe bent pipe section, discontinuous material plugs can be conveniently formed in the conveying pipeline under the combined action of the air source valve set, the conveying speed of the materials is decreased, severe accumulation and collision between the materials are reduced, and the conveying efficiency of the materials is improved. And the problem that the hot direct reduction iron material in the pneumatic conveying system is easy to break is effectively solved.

Description

Technical Field

[0001] The utility model relates to the technical field of pneumatic conveying, and particularly relates to a pneumatic conveying system for hot direct reduced iron materials. Background Technique

[0002] Direct reduced iron is a high-quality charge for electric furnaces and converters, and is suitable for the production of high-quality steel and special steel. Since the smelting of direct reduced iron does not use coke, this process is a new high-quality, low-consumption and low-pollution iron-smelting process, and is also one of the world's leading steel-smelting technologies.

[0003] Hot charging and hot delivery of direct reduced iron (DRI) is an important measure to reduce the power consumption of electric arc furnaces. According to research results, when direct reduced iron (DRI) replaces scrap steel for electric arc furnace smelting, for every 100 °C increase in the furnace inlet temperature of direct reduced iron (DRI), about 25 kw•h of electric energy can be saved per ton of steel. When hot charging with hot direct reduced iron (HDRI) at about 700 °C, the power consumption per ton of steel is reduced by 110 - 160 kwh compared with cold DRI / HBI smelting, the melting time can be reduced by 10 - 20% (about 10 - 15 minutes), and the production capacity of the electric furnace can be increased by more than 15%.

[0004] Direct charging of hot direct reduced iron into an electric furnace for smelting can greatly reduce power consumption and improve the production capacity of the electric furnace, providing conditions for further reducing energy consumption in the short process of shaft furnace production of hot direct reduced iron (HRDI) (600 - 700 °C) - electric furnace.

[0005] In recent years, most newly built gas-based shaft furnace direct reduced iron - electric arc furnace steelmaking production lines adopt the process of hot discharging, hot conveying and hot charging of direct reduced iron into an electric furnace. Based on the principle of "the lowest conveying energy consumption and the simplest conveying device", the following are the main methods for realizing industrialized hot conveying of direct reduced iron: gas pipeline conveying method; hot conveyor method; heat preservation tank method, etc.

[0006] The gas pipeline conveying method uses hot gas or hot nitrogen as the conveying gas, and adopts a pipeline closed type to convey hot direct reduced iron (HDRI). The process layout of the gas-based shaft furnace and the electric furnace is relatively flexible and convenient, and the floor area is relatively small; however, the maximum conveying distance of this method is ≤200 m, and there are problems such as easy wear of equipment, easy jamming of materials, easy breakage, and high energy consumption. Content of the Utility Model

[0007] The problems existing in the prior art are as follows: In the pneumatic conveying system of conventional hot direct reduced iron materials to the electric arc furnace, there are problems of easy wear of equipment and easy fragmentation of materials. In view of the above problems, the present utility model provides a pneumatic conveying system for hot direct reduced iron materials, which includes a gas-based iron shaft furnace, a double-layer bell valve feeder, a hot direct reduced iron transmitter, a conveying pipeline, a solid-gas separation device, a hot direct reduced iron storage bin, a gas recovery pipeline, a gas recovery device, a gas source intake pipeline, an electric arc furnace and a gas source valve group.

[0008] A discharge gate valve is arranged at the bottom of the gas-based iron shaft furnace.

[0009] An upper bell valve and a lower bell valve are respectively arranged at the top and bottom of the double-layer bell valve feeder.

[0010] A discharge chute is further arranged between the gas-based iron shaft furnace and the double-layer bell valve feeder. When the discharge gate valve at the bottom of the gas-based iron shaft furnace and the upper bell valve of the double-layer bell valve feeder are opened simultaneously, the materials in the gas-based iron shaft furnace enter the double-layer bell valve feeder through the discharge chute. The double-layer bell valve feeder and the hot direct reduced iron transmitter are connected and controlled through a valve. When the lower bell valve of the double-layer bell valve feeder is opened, the materials in the double-layer bell valve feeder enter the hot direct reduced iron transmitter.

[0011] The hot direct reduced iron transmitter includes a transmitter upper storage tank and a plug-forming transmitter which are connected in sequence from top to bottom. The end face adjacent to the plug-forming transmitter of the transmitter upper storage tank is hermetically and fixedly connected.

[0012] The plug-forming transmitter includes a plug-forming storage bin and an inclined tee which are connected to each other up and down.

[0013] The inclined tee includes a bent pipe section and a straight pipe section. The side walls of the bent pipe section and the straight pipe section are connected to each other. The inner diameters of the bent pipe section and the straight pipe section are equal. The end face adjacent to the plug-forming storage bin of the bent pipe section is hermetically and fixedly connected. The axis at the end face adjacent to the plug-forming storage bin of the bent pipe section is perpendicular to the ground. The end face adjacent to the straight pipe section of the bent pipe section is hermetically and fixedly connected. The axis at the end face adjacent to the straight pipe section of the bent pipe section and the axis of the straight pipe section form an angle of 15-20° in the opposite direction of material conveyance.

[0014] One end of the straight pipe section of the inclined tee is connected to the conveying pipeline.

[0015] The other end of the straight pipe section of the inclined tee is connected to an intake short pipe.

[0016] The other end of the conveying pipeline is connected to the top of the solid-gas separation device.

[0017] The hot direct reduced iron storage bin is located below the solid-gas separation device, and the two are connected to each other through a double-layer gate plate type discharger.

[0018] A charging chute is also provided at the bottom of the hot direct reduced iron storage bin, and the hot direct reduced iron storage bin adds materials into the electric arc furnace through the charging chute.

[0019] The gas source valve group includes a plugging gas source valve group, a pulse gas source valve group, and a plug cleaning gas source valve group.

[0020] One ends of the plugging gas source valve group, the pulse gas source valve group, and the plug cleaning gas source valve group are all interconnected with the gas source inlet pipeline.

[0021] The other ends of the pulse gas source valve group and the plug cleaning gas source valve group are interconnected with the straight pipe section of the inclined tee through the inlet short pipe.

[0022] The other end of the plugging gas source valve group is interconnected with the plugging storage bin on the upper part of the plugging generator through the inlet short pipe.

[0023] The top of the solid-gas separation device is interconnected with the gas recovery device through the gas recovery pipeline.

[0024] The other end of the gas recovery device is interconnected with the gas source inlet pipeline, and the gas pressurized and heated by the gas recovery device continuously enters the gas source inlet pipeline.

[0025] A pressure transmitter is also provided between the plugging gas source valve group and the inlet short pipe to monitor the gas pressure in the conveying pipeline in real time.

[0026] Level gauges are provided on the upper part of the side walls of both the hot direct reduced iron transmitter and the plugging storage bin to monitor the change in the volume of materials in the container in real time.

[0027] Preferably, the plugging storage bin includes a conical inner wall and a conical outer wall.

[0028] The conical outer wall is circumferentially sleeved outside the conical inner wall.

[0029] A closed cavity sandwich is formed circumferentially between the conical outer wall and the conical inner wall.

[0030] The conical inner wall includes a plurality of conical sections fixedly connected in sequence from top to bottom.

[0031] Among the conical sections, the end faces of two adjacent ones are frustum end faces, and the frustum end faces of two adjacent ones are mutually embedded, with the upper frustum end face embedded into the lower frustum end face.

[0032] Among the conical sections, a groove is provided on one of the frustum end faces of two adjacent frustum end faces.

[0033] The grooves are evenly distributed circumferentially along the frustum end face, the width of the grooves is 0.3 - 0.4 mm, and the depth of the grooves is 0.1 - 0.2 mm.

[0034] The length of the groove is equal to and parallel to the generatrix of the frustum end face.

[0035] When the frustum end faces of adjacent conical segments are in contact, an air inlet channel is formed between the frustum end faces of adjacent conical segments. The direction of the airflow in the air inlet channel pushes the material in the plug-forming storage bin towards the straight pipe of the three inclined pipes.

[0036] The cavity sandwich is in communication with the air inlet channel.

[0037] The plug-forming air source valve group conveys gas into the cavity sandwich through an air inlet short pipe, and the gas in the cavity sandwich jets into the plug-forming storage bin through the air inlet channel.

[0038] Preferably, the conical segment is divided into five parts, including a first conical segment, a second conical segment, a third conical segment, a fourth conical segment, and a fifth conical segment that are fixedly connected in sequence from top to bottom.

[0039] The end faces of the first conical segment adjacent to the second conical segment, the third conical segment, the fourth conical segment, and the fifth conical segment are all frustum end faces, and the taper of the frustum end face is 15 - 25°.

[0040] The frustum end face of the first conical segment is embedded into the frustum end face of the second conical segment adjacent thereto.

[0041] The frustum end face of the second conical segment is embedded into the frustum end face of the third conical segment adjacent thereto.

[0042] The frustum end face of the third conical segment is embedded into the frustum end face of the fourth conical segment adjacent thereto.

[0043] The frustum end face of the fourth conical segment is embedded into the frustum end face of the fifth conical segment adjacent thereto.

[0044] A groove is provided on one of the frustum end faces of the adjacent frustum end faces of the first conical segment, the second conical segment, the third conical segment, the fourth conical segment, and the fifth conical segment.

[0045] The grooves are evenly distributed circumferentially on the frustum end face, the width of the groove is 0.3 - 0.4 mm, and the depth of the groove is 0.1 - 0.2 mm.

[0046] The length of the groove is equal to and parallel to the generatrix of the frustum end face.

[0047] When the frustum end faces of the adjacent first conical segment, second conical segment, third conical segment, fourth conical segment, and fifth conical segment are in contact, an air inlet channel is formed between the adjacent frustum end faces.

[0048] The cavity sandwich is in communication with the air inlet channel.

[0049] Preferably, the material of the conical inner wall of the plug-forming storage bin is wear-resistant silicon carbide.

[0050] Preferably, the inclined tee includes an inner inclined pipe wall and an outer inclined pipe wall. An adiabatic and heat-insulating material IV is filled between the inner inclined pipe wall and the outer inclined pipe wall, and the material of the inner inclined pipe wall is wear-resistant silicon carbide.

[0051] Preferably, a plurality of in-line boosters are arranged on the conveying pipeline. The in-line boosters are in communication with the conveying pipeline, and the adjacent end faces of the two are hermetically and fixedly connected. The distance between adjacent in-line boosters is 3 - 5 m.

[0052] The in-line booster includes a connecting pipe and an outer connecting pipe wall.

[0053] The outer connecting pipe wall is sleeved on the connecting pipe, and the adjacent end faces of the two are hermetically and fixedly connected.

[0054] A gas source distribution chamber and two heat-insulating cavities that are isolated from each other are formed between the outer connecting pipe wall and the connecting pipe along the axial direction of the connecting pipe.

[0055] The two heat-insulating cavities are distributed on both sides of the gas source distribution chamber, adjacent to the outer walls on the left and right sides of the gas source distribution chamber.

[0056] The end face of the gas source distribution chamber adjacent to the heat-insulating cavity is hermetically and fixedly connected.

[0057] Air inlet channels are circumferentially and uniformly arranged on the surface of the outer connecting pipe wall.

[0058] The air inlet direction of the air inlet channel is consistent with the conveying direction of the material inside the connecting pipe.

[0059] The air inlet channel is only in communication with the gas source distribution chamber and is not in communication with the heat-insulating cavity.

[0060] The gas source distribution chamber is in communication with one end of the in-line booster gas source valve group through an air inlet short pipe.

[0061] The other end of the in-line booster gas source valve group is in communication with the gas source inlet pipeline.

[0062] When the in-line booster gas source valve group is opened, gas is sprayed into the gas source distribution chamber through the air inlet short pipe. The gas in the gas source distribution chamber enters the connecting pipe through the air inlet channels opened on the outer connecting pipe wall. The heat-insulating cavities are all filled with an adiabatic and heat-insulating material I.

[0063] Preferably, the connecting pipe includes a feed pipe section, a middle pipe section, and a discharge pipe section that are in communication with each other.

[0064] The adjacent end faces of the feed pipe section, the middle pipe section, and the discharge pipe section are fixedly connected.

[0065] The end faces adjacent to each other among the feed pipe section, the middle pipe section and the discharge pipe section are all frustum end faces.

[0066] The frustum end face of the feed pipe section is embedded into the frustum end face adjacent to it in the middle pipe section.

[0067] The frustum end face of the middle pipe section is embedded into the frustum end face adjacent to it in the discharge pipe.

[0068] One of the frustum end faces adjacent to each other among the feed pipe section, the middle pipe section and the discharge pipe section is provided with grooves. The grooves are evenly distributed along the circumferential direction of the frustum end face. The included angle between the axes of adjacent grooves is 15 - 30°. The depth of the groove is 0.1 - 0.2 mm, the width of the groove is 0.3 - 0.4 mm, and the length of the groove is equal to and parallel to the generatrix length of the frustum end face.

[0069] When the frustum end faces adjacent to each other among the feed pipe section, the middle pipe section and the discharge pipe section are fitted and fixed, an air inlet channel is formed between the adjacent frustum end faces. The included angle between the axis of the air inlet channel and the conveying direction of the material in the connecting pipe is 15 - 25°.

[0070] Preferably, the material of the connecting pipe is wear-resistant silicon carbide.

[0071] Preferably, the conveying pipeline includes an inner wall of the conveying pipe and an outer wall of the conveying pipe. An adiabatic and heat-insulating material II is filled between the inner wall and the outer wall of the conveying pipe. The conveying pipeline includes a plurality of horizontal gas conveying pipe sections and a plurality of vertical gas conveying pipe sections arranged along the material conveying direction.

[0072] Adjacent horizontal gas conveying pipe sections are interconnected through wear-resistant elbows. The wear-resistant elbows are hermetically and fixedly connected to the end faces adjacent to each other between the wear-resistant elbows and the horizontal gas conveying pipe sections.

[0073] The wear-resistant elbow includes an inner wall of the elbow and an outer wall of the elbow. The outer wall of the elbow is sleeved outside the inner wall of the elbow. An adiabatic and heat-insulating material III is filled between the inner wall and the outer wall of the elbow. The material of the inner wall of the elbow is wear-resistant silicon carbide, and the material of the outer wall of the elbow is 20# steel.

[0074] Preferably, the gas recovery device includes a multi-tube water cooling device, a dust collector, a gas buffer tank, a conveying gas pressurizing device and a conveying gas heating device that are sequentially interconnected. The gas buffer tank is also connected to a gas source supplement device to continuously supplement nitrogen into the gas buffer tank.

[0075] Preferably, in the present utility model, the horizontal gas conveying pipe sections between adjacent conveying pipelines and between adjacent vertical gas conveying pipelines are all connected through flanges. In order to increase the sealing effect of the flanges, a sealing gasket can also be provided between adjacent flange heads. In order to facilitate the assembly between adjacent flange heads, there are correspondingly arranged concave parts and convex parts between adjacent flange heads.

[0076] The utility model has the following beneficial effects:

[0077] (1) Through the design of the plug-forming transmitter structure, the axis of the three-inclined-tube elbow section at the bottom of the utility model is designed to form an angle of 15-20° with the axis of the straight pipe section in the opposite direction of material transportation. This design enables the material, after entering the elbow section, not to slide into the conveying pipeline without external force, and a stable material plug will be formed in the elbow section. Only when the material in the elbow section is blown by the plug-forming pulse gas source will it slide into the conveying pipeline. After the pulse gas source valve group and the plug-forming pulse gas source are simultaneously opened, the material in the elbow section continuously enters the conveying pipeline. When the pressure in the conveying pipeline is higher than 0.4-0.42 MPa, the plug-forming gas source valve group is closed to stop feeding material into the conveying pipeline. At this time, the pulse gas source valve group is still in the open state, and the pulse gas source valve group blows nitrogen to push the material to conduct pneumatic transportation forward in the conveying pipeline, and the pressure in the conveying pipeline will decrease. When the gas pressure in the conveying pipeline is lower than 0.28-0.3 MPa, the plug-forming gas source valve group is opened again to continue feeding material into the conveying pipeline. This operation enables discontinuous material plugs to be formed in the conveying pipeline, significantly slows down the transportation speed of the material in the conveying pipeline, thereby significantly reducing the abrasion of the inner wall of the conveying pipeline caused by the material during pneumatic transportation, and also reducing the probability of serious collisions between materials, effectively solving the problems of easy material jamming and easy material breakage of the directly reduced iron material in the hot conveying pipeline;

[0078] (2) A number of in-line boosters are arranged on the conveying pipeline of the utility model along the material transportation direction. The in-line boosters are interconnected with the conveying pipeline and are sequentially distributed along the transportation direction of the conveying pipeline. The distance between adjacent in-line boosters is 3-5 m. The in-line boosters are interconnected with the conveying pipeline, and the end faces adjacent to the conveying pipeline are hermetically and fixedly connected by flanges. A gas source distribution chamber is formed between the connecting pipe of the in-line booster and the outer wall of the connecting pipe. The in-line booster gas source valve group sprays gas into the gas source distribution chamber through the intake short pipe. The gas in the gas source distribution chamber enters the connecting pipe through the intake channels opened on the outer wall of the connecting pipe. The blowing direction of the air flow is consistent with the transportation direction of the material in the conveying pipeline. The jetting duration of each in-line booster is 300-500 ms, and the intermittent time is 2-3 s. When the in-line boosters and the pulse gas source valve group are simultaneously opened, the in-line boosters intermittently blow nitrogen into the conveying pipeline to form an air film between the material and the inner wall of the conveying pipeline, which can further reduce the friction coefficient of the material against the inner wall of the conveying pipeline and reduce the wear of the inner wall of the conveying pipeline;

[0079] (3) When blockage occurs in the conveying pipeline, the in-line booster and the blockage clearing air source valve group are simultaneously opened. The presence of the in-line booster significantly reduces the gas pressure and flow rate that the blockage clearing air source valve group needs to provide, effectively shortening the time required for blockage clearing and greatly improving production efficiency.

[0080] (4) The inner walls of the conveying pipeline, wear-resistant elbows, and inclined tees of the present utility model are all made of wear-resistant silicon carbide, having good wear resistance. Heat-insulating materials are filled between the inner and outer walls of the conveying pipeline, wear-resistant elbows, and inclined tees, which can effectively prevent large fluctuations in the temperature of the materials in the hot direct reduced iron material pneumatic conveying system caused by the external environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Figure 1 : Schematic structural diagram of a hot direct reduced iron material pneumatic conveying system provided by the present utility model.

[0082] Figure 2 : Figure 1 Enlarged structural diagram of part A in

[0083] Figure 3 : Schematic structural diagram of the in-line booster in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0084] Figure 4 : Schematic structural diagram of the gas recovery device in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0085] Figure 5 : Schematic structural diagram of the conveying pipeline in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0086] Figure 6 : Schematic structural diagram of the wear-resistant elbow in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0087] Figure 7 : Schematic cross-sectional structural diagram of the plug sender in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0088] Figure 8 : Schematic structural diagram of the hot direct reduced iron sender in the hot direct reduced iron material pneumatic conveying system used in the present utility model.

[0089] In the figure, 1. Gas-based iron shaft furnace, 2. Upper storage tank of the transmitter, 3. Short intake pipe, 4. Discharge gate valve, 5. Discharge chute, 6. Plug-forming gas source valve group, 7. Pressure transmitter, 8. Double-layer bellows valve type feeder, 9. Hot direct reduced iron transmitter, 10. Conveying pipeline, 11. In-line booster, 12. Plug-forming storage bin, 13. Pulse gas source valve group, 14. In-line booster gas source valve group, 17. Solid-gas separation device, 18. Double-layer gate plate type discharger, 19. Hot direct reduced iron storage bin, 20. Feeding chute, 21. Electric arc furnace, 22. Gas recovery pipeline, 23. Gas recovery device, 24. Gas source intake pipeline, 28. Level gauge, 29. Plug-cleaning gas source valve group, 1-2. Feed pipe section, 1-6. Thermal insulation material I, 1-7. Gas source distribution chamber, 1-8. Middle pipe section, 1-10. Intake passage, 1-13. Discharge pipe section, 2-4. Multi-tube water cooling device, 2-5. Dust collector, 2-6. Gas buffer tank, 2-7. Conveying gas pressurizing device, 2-8. Gas heating device, 2-10. Gas source supplement device, 3-2. Outer wall of the conveying pipe, 3-3. Thermal insulation material II, 3-4. Inner wall of the conveying pipe, 4-1. Conical outer wall, 4-2. Cavity sandwich, 4-3. Conical inner wall, 4-4. Elbow section, 4-5. Outer wall of the inclined pipe, 4-6. Thermal insulation material IV, 4-7. Inner wall of the inclined pipe, 4-8. Straight pipe section, 5-2. Outer wall of the elbow, 5-3. Thermal insulation material III, 5-4. Inner wall of the elbow, I. First conical section, II. Second conical section, III. Third conical section, IV. Fourth conical section, V. Fifth conical section. Detailed implementation mode

[0090] The present invention will be described in detail below in conjunction with embodiments. However, it should be understood that the following embodiments are only illustrative examples of the implementation modes of the present invention, rather than limiting the scope of the present invention.

[0091] As Figure 1-8 shown, a pneumatic conveying system for hot direct reduced iron materials provided by the present invention includes a gas-based iron shaft furnace 1, a double-layer bellows valve type feeder 8, a hot direct reduced iron transmitter 9, a conveying pipeline 10, a solid-gas separation device 17, a hot direct reduced iron storage bin 19, a gas recovery pipeline 22, a gas recovery device 23, a gas source intake pipeline 24, an electric arc furnace 21 and a gas source valve group.

[0092] A discharge gate valve 4 is arranged at the bottom of the gas-based iron shaft furnace 1.

[0093] An upper bellows valve and a lower bellows valve are respectively arranged at the top and bottom of the double-layer bellows valve type feeder 8.

[0094] A discharge chute pipe 5 is also provided between the gas-based iron shaft furnace 1 and the double-layer bell valve feeder 8. When the discharge gate valve 4 at the bottom of the gas-based iron shaft furnace 1 and the upper bell valve of the double-layer bell valve feeder 8 are opened simultaneously, the materials in the gas-based iron shaft furnace 1 enter the double-layer bell valve feeder 8 through the discharge chute pipe 5. When the lower bell valve of the double-layer bell valve feeder 8 is opened, the materials in the double-layer bell valve feeder 8 enter the hot direct reduced iron transmitter 9.

[0095] The hot direct reduced iron transmitter 9 includes a transmitter upper storage tank 2 and a plug-forming transmitter that are connected in sequence from top to bottom. The end face of the transmitter upper storage tank 2 adjacent to the plug-forming transmitter is hermetically and fixedly connected.

[0096] The plug-forming transmitter includes a plug-forming storage bin 12 and an inclined tee that communicate with each other up and down.

[0097] The inclined tee includes a bent pipe section 4-4 and a straight pipe section 4-8. The side walls of the bent pipe section 4-4 and the straight pipe section 4-8 are interconnected. The inner diameters of the bent pipe section 4-4 and the straight pipe section 4-8 are equal. The end face of the bent pipe section 4-4 adjacent to the plug-forming storage bin 12 is hermetically and fixedly connected. The axis at the end face of the bent pipe section 4-4 adjacent to the plug-forming storage bin 12 is perpendicular to the ground. The end face of the bent pipe section 4-4 adjacent to the straight pipe section 4-8 is hermetically and fixedly connected. The axis at the end face of the bent pipe section 4-4 adjacent to the straight pipe section 4-8 forms an angle of 15-20° with the axis of the straight pipe section 4-8 in the opposite direction of material transportation.

[0098] One end of the straight pipe section 4-8 of the inclined tee is interconnected with the conveying pipeline 10.

[0099] The other end of the straight pipe section 4-8 of the inclined tee is interconnected with the intake short pipe 3.

[0100] The other end of the conveying pipeline 10 is interconnected with the top of the solid-gas separation device 17.

[0101] The hot direct reduced iron storage bin 19 is located below the solid-gas separation device 17, and the two are interconnected through a double-layer gate plate type discharge device 18.

[0102] A feeding chute pipe 20 is also provided at the bottom of the hot direct reduced iron storage bin 19. The hot direct reduced iron storage bin 19 adds materials into the electric arc furnace 21 through the feeding chute pipe 20.

[0103] The gas source valve group includes a plug-forming gas source valve group 6, a pulse gas source valve group 13, and a plug-cleaning gas source valve group 29.

[0104] One ends of the plug-forming gas source valve group 6, the pulse gas source valve group 13, and the plug-cleaning gas source valve group 29 are all interconnected with the gas source intake pipeline 24.

[0105] The other ends of the pulse gas source valve group 13 and the plug cleaning gas source valve group 29 are interconnected with the straight pipe section 4-8 of the inclined tee through the intake short pipe 3.

[0106] The other end of the plug forming gas source valve group 6 is interconnected with the plug forming storage bin 12 above the plug forming generator through the intake short pipe 3.

[0107] The top of the solid-gas separation device 17 is interconnected with the gas recovery device 23 through the gas recovery pipeline 22.

[0108] The other end of the gas recovery device 23 is interconnected with the gas source intake pipeline 24, and the gas pressurized and heated by the gas recovery device 23 continuously enters the gas source intake pipeline 24.

[0109] A pressure transmitter 7 is also provided between the plug forming gas source valve group 6 and the intake short pipe 3 to monitor the gas pressure in the conveying pipeline 10 in real time.

[0110] Level gauges 28 are provided on both the hot direct reduced iron transmitter 9 and the upper part of the side wall of the plug forming storage bin 12 to monitor the change in the volume of the material in the container in real time.

[0111] Preferably, the plug forming storage bin 12 includes a conical inner wall 4-3 and a conical outer wall 4-1.

[0112] The conical outer wall 4-1 is circumferentially sleeved outside the conical inner wall 4-3.

[0113] A sealed cavity sandwich 4-2 is formed circumferentially between the conical outer wall 4-1 and the conical inner wall 4-3.

[0114] The conical inner wall 4-3 includes a plurality of conical sections fixedly connected in sequence from top to bottom.

[0115] Among the conical sections, the end faces of two adjacent ones are frustum end faces, and the frustum end faces of two adjacent ones are mutually fitted, with the upper frustum end face embedded into the lower frustum end face.

[0116] Among the conical sections, a groove is provided on one of the frustum end faces of two adjacent frustum end faces.

[0117] The grooves are evenly distributed circumferentially along the frustum end face, the width of the grooves is 0.3 - 0.4 mm, and the depth of the grooves is 0.1 - 0.2 mm.

[0118] The length of the grooves is equal to and parallel to the generatrix of the frustum end face.

[0119] When the frustum end faces of two adjacent conical sections are in contact, an intake channel 1-10 is formed between the frustum end faces of two adjacent conical sections, and the direction of the airflow in the intake channel 1-10 pushes the material in the plug forming storage bin 12 into the straight pipe of the three inclined pipes.

[0120] The cavity sandwich layer 4-2 is in communication with the intake passage 1-10.

[0121] The plug-forming gas source valve group 6 delivers gas into the cavity sandwich layer 4-2 through the short intake pipe 3, and the gas in the cavity sandwich layer 4-2 jets into the plug-forming storage bin 12 through the intake passage 1-10.

[0122] In a specific embodiment, the conical section is divided into five parts, including a first conical section I, a second conical section II, a third conical section III, a fourth conical section IV, and a fifth conical section V, which are fixedly connected in sequence from top to bottom.

[0123] The end faces adjacent to each other between the first conical section I and the second conical section II, the third conical section III, the fourth conical section IV, and the fifth conical section V are all frustum end faces, and the taper of the frustum end faces is 15 - 25°.

[0124] The frustum end face of the first conical section I is embedded into the frustum end face adjacent to it of the second conical section II.

[0125] The frustum end face of the second conical section II is embedded into the frustum end face adjacent to it of the third conical section III.

[0126] The frustum end face of the third conical section III is embedded into the frustum end face adjacent to it of the fourth conical section IV.

[0127] The frustum end face of the fourth conical section IV is embedded into the frustum end face adjacent to it of the fifth conical section V.

[0128] A groove is provided on one of the frustum end faces adjacent to each other between the first conical section I and the second conical section II, the third conical section III, the fourth conical section IV, and the fifth conical section V.

[0129] The grooves are evenly distributed circumferentially on the frustum end face, the width of the grooves is 0.3 - 0.4 mm, and the depth of the grooves is 0.1 - 0.2 mm.

[0130] The length of the grooves is equal to and parallel to the generatrix of the frustum end face.

[0131] When the frustum end faces adjacent to each other between the first conical section I and the second conical section II, the third conical section III, the fourth conical section IV, and the fifth conical section V are in contact, an intake passage 1-10 is formed between the adjacent frustum end faces.

[0132] The cavity sandwich layer 4-2 is in communication with the intake passage 1-10.

[0133] In a specific embodiment, the material of the conical inner wall 4-3 of the plug-forming storage bin 12 is wear-resistant silicon carbide.

[0134] In a specific embodiment, the inclined tee includes an inner wall 4-7 of the inclined pipe and an outer wall 4-5 of the inclined pipe. An adiabatic and heat-insulating material 4-6 is filled between the inner wall 4-7 of the inclined pipe and the outer wall 4-5 of the inclined pipe. The material of the inner wall 4-7 of the inclined pipe is wear-resistant silicon carbide.

[0135] In a specific embodiment, a plurality of in-line boosters 11 are provided on the conveying pipeline 10. The in-line boosters 11 are in communication with the conveying pipeline 10 and are hermetically and fixedly connected to the adjacent end faces thereof. The distance between adjacent in-line boosters 11 is 3 to 5 m.

[0136] The in-line booster 11 includes a connecting pipe and an outer wall of the connecting pipe.

[0137] The outer wall of the connecting pipe is sleeved on the outer wall of the connecting pipe, and the adjacent end faces thereof are hermetically and fixedly connected.

[0138] A gas source distribution chamber 1-7 and two heat-insulating cavities that are isolated from each other are formed between the outer wall of the connecting pipe and the connecting pipe along the axial direction of the connecting pipe.

[0139] The two heat-insulating cavities are distributed on both sides of the gas source distribution chamber 1-7 and are adjacent to the outer walls on the left and right sides of the gas source distribution chamber 1-7.

[0140] The end faces of the gas source distribution chamber 1-7 adjacent to the heat-insulating cavities are hermetically and fixedly connected.

[0141] Air inlet channels 1-10 are circumferentially and uniformly arranged on the surface of the outer wall of the connecting pipe.

[0142] The air inlet direction of the air inlet channels 1-10 is consistent with the conveying direction of the material inside the connection.

[0143] The air inlet channels 1-10 are only in communication with the gas source distribution chamber 1-7 and are not in communication with the heat-insulating cavities.

[0144] The gas source distribution chamber 1-7 is in communication with one end of the in-line booster gas source valve group 14 through an intake short pipe 3.

[0145] The other end of the in-line booster gas source valve group 14 is in communication with the gas source intake pipeline 24.

[0146] When the in-line booster gas source valve group 14 is opened, gas is injected into the gas source distribution chamber 1-7 through the intake short pipe 3. The gas in the gas source distribution chamber 1-7 enters the connecting pipe through the air inlet channels 1-10 opened on the outer wall of the connecting pipe. The heat-insulating cavities are all filled with a first adiabatic and heat-insulating material 1-6.

[0147] In a specific embodiment, the connecting pipe includes a feed pipe section 1-2, a middle pipe section 1-8, and a discharge pipe section 1-13 that are in communication with each other.

[0148] The end faces adjacent to the feed pipe section 1-2, the middle pipe section 1-8 and the discharge pipe section 1-13 are fixedly connected.

[0149] The end faces adjacent to each other among the feed pipe section 1-2, the middle pipe section 1-8 and the discharge pipe section 1-13 are all frustum end faces.

[0150] The frustum end face of the feed pipe section 1-2 is embedded into the frustum end face adjacent to it in the middle pipe section 1-8.

[0151] The frustum end face of the middle pipe section 1-8 is embedded into the frustum end face adjacent to it in the discharge pipe.

[0152] One of the frustum end faces adjacent to each other among the feed pipe section 1-2, the middle pipe section 1-8 and the discharge pipe section 1-13 is provided with grooves. The grooves are evenly distributed along the circumferential direction of the frustum end face. The included angle between the axes of adjacent grooves is 15-30°. The groove depth of the groove is 0.1-0.2 mm, the groove width of the groove is 0.3-0.4 mm, and the length of the groove is equal to and parallel to the generatrix length of the frustum end face.

[0153] When the frustum end faces adjacent to each other among the feed pipe section 1-2, the middle pipe section 1-8 and the discharge pipe section 1-13 are fitted and fixed, an air inlet channel 1-10 is formed between the frustum end faces adjacent to each other. The included angle between the axis of the air inlet channel 1-10 and the conveying direction of the material in the connecting pipe is 15-25°.

[0154] In a specific embodiment, the material of the connecting pipe is wear-resistant silicon carbide.

[0155] In a specific embodiment, the conveying pipeline 10 includes a conveying pipe inner wall 3-4 and a conveying pipe outer wall 3-2, and a heat-insulating and heat-preserving material two 3-3 is filled between the conveying pipe inner wall 3-4 and the outer wall.

[0156] In a specific embodiment, the conveying pipeline 10 includes a plurality of horizontal gas pipeline sections and a plurality of vertical gas pipeline sections arranged along the material conveying direction.

[0157] Adjacent horizontal gas pipeline sections are interconnected through wear-resistant elbows. The wear-resistant elbows are hermetically and fixedly connected to the end faces adjacent to the horizontal gas pipeline sections and the horizontal gas pipeline sections.

[0158] The wear-resistant elbow includes an elbow inner wall 5-4 and an elbow outer wall 5-2. The elbow outer wall 5-2 is sleeved outside the elbow inner wall 5-4. A heat-insulating and heat-preserving material three 5-3 is filled between the elbow inner wall 5-4 and the elbow outer wall 5-2. The material of the elbow inner wall 5-4 is wear-resistant silicon carbide, and the material of the elbow outer wall 5-2 is 20# steel.

[0159] In a specific embodiment, the gas recovery device 23 includes a multi-tube water cooling device 2-4, a dust collector 2-5, a gas buffer tank 2-6, a conveying gas pressurizing device 2-7, and a conveying gas heating device 2-8 that are sequentially interconnected. The gas buffer tank 2-6 is also connected to a gas source supplement device 2-10 to continuously supplement nitrogen into the gas buffer tank 2-6. The dust collector is a high-temperature resistant pulse jet metal filter cartridge dust collector or a high-temperature resistant pulse jet ceramic filter cartridge dust collector.

[0160] Enlightened by the above ideal embodiments of the present invention, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present invention. The technical scope of the present invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A pneumatic conveying system for hot direct reduced iron materials, characterized in that it includes a gas-based iron shaft furnace (1), a double-layer bell valve feeder (8), a hot direct reduced iron transmitter (9), a conveying pipeline (10), a solid-gas separation device (17), a hot direct reduced iron storage bin (19), a gas recovery pipeline (22), a gas recovery device (23), a gas source intake pipeline (24), an electric arc furnace (21) and a gas source valve group; The gas-based iron shaft furnace (1) is interconnected with the double-layer bell valve feeder (8) through a discharge chute (5), the double-layer bell valve feeder (8) is connected to the hot direct reduced iron transmitter (9) through valve control, the hot direct reduced iron transmitter (9) is sequentially connected to the conveying pipeline (10), the solid-gas separation device (17) and the hot direct reduced iron storage bin (19), the hot direct reduced iron storage bin (19) is interconnected with the electric arc furnace (21) through a feeding chute (20), and the top of the solid-gas separation device (17) is sequentially connected to the gas recovery pipeline (22), the gas recovery device (23) and the gas source intake pipeline (24); The hot direct reduced iron transmitter (9) includes a transmitter upper storage tank (2) and a plug-forming transmitter that are sequentially connected up and down. The plug-forming transmitter includes a plug-forming storage bin (12) and an inclined tee that are interconnected up and down. The inclined tee includes a bent pipe section (4-4) and a straight pipe section (4-8). The bent pipe section (4-4) is interconnected with the side wall of the straight pipe section (4-8). The end face of the bent pipe section (4-4) adjacent to the plug-forming storage bin (12) is hermetically fixedly connected. The end face of the bent pipe section (4-4) adjacent to the straight pipe section (4-8) is hermetically fixedly connected. The axis at the adjacent end face of the bent pipe section (4-4) and the straight pipe section (4-8) forms an angle of ≤20° with the axis of the straight pipe section (4-8) in the opposite direction of material transportation. The straight pipe section (4-8) is interconnected with the conveying pipeline (10); The gas source valve group includes a plug-forming gas source valve group (6), a pulse gas source valve group (13) and a plug-cleaning gas source valve group (29). One ends of the plug-forming gas source valve group (6), the pulse gas source valve group (13) and the plug-cleaning gas source valve group (29) are all interconnected with the gas source intake pipeline (24); The other ends of the pulse gas source valve group (13) and the plug-cleaning gas source valve group (29) are interconnected with the straight pipe section (4-8) of the inclined tee through an intake short pipe (3); The other end of the plug-forming gas source valve group (6) is interconnected with the plug-forming storage bin (12) above the plug-forming generator through an intake short pipe (3).

2. The pneumatic conveying system for hot direct reduced iron materials according to claim 1, characterized in that a pressure transmitter (7) is further provided between the plug-forming gas source valve group (6) and the intake short pipe (3) to monitor the gas pressure in the conveying pipeline (10) in real time.

3. The pneumatic conveying system for hot direct reduced iron materials according to claim 1, characterized in that, The plug-forming storage bin (12) includes a conical inner wall (4-3) and a conical outer wall (4-1). The conical outer wall (4-1) is circumferentially sleeved outside the conical inner wall (4-3). A sealed cavity sandwich (4-2) is formed circumferentially between the conical outer wall (4-1) and the conical inner wall (4-3). The conical inner wall (4-3) is circumferentially and uniformly provided with air inlet channels (1-10). The direction of the inlet air flow of the air inlet channels (1-10) is the same as the direction of the material conveying in the plug-forming storage bin (12). The cavity sandwich (4-2) is in communication with the air inlet channels (1-10).

4. A pneumatic conveying system for hot direct reduced iron materials according to claim 1, characterized in that, The material of the conical inner wall (4-3) of the plug-forming storage bin (12) is wear-resistant silicon carbide.

5. The pneumatic conveying system for hot direct reduced iron materials according to claim 1, wherein The inclined three-way pipe includes an inclined pipe inner wall (4-7) and an inclined pipe outer wall (4-5). Heat-insulating and heat-preserving material IV (4-6) is filled between the inclined pipe inner wall (4-7) and the inclined pipe outer wall (4-5). The material of the inclined pipe inner wall (4-7) is wear-resistant silicon carbide.

6. The pneumatic conveying system for hot direct reduced iron materials according to claim 1, wherein, A number of in-line boosters (11) are provided on the conveying pipeline (10). The in-line boosters (11) are in communication with the conveying pipeline (10) and the adjacent end faces of the two are hermetically and fixedly connected. The in-line booster air source valve group (14) blows gas into the conveying pipeline (10) through the in-line boosters (11). The direction of the gas blowing is the same as the direction of the material conveying in the conveying pipeline (10).

7. The pneumatic conveying system for hot direct reduced iron materials according to claim 6, characterized in that The in-line booster (11) includes a connecting pipe and an outer wall of the connecting pipe. The outer wall of the connecting pipe is sleeved on the connecting pipe, and the adjacent end faces of the two are hermetically and fixedly connected. An air source distribution chamber (1-7) and two heat-preserving cavities that are isolated from each other are formed axially along the connecting pipe between the outer wall of the connecting pipe and the connecting pipe. The two heat-preserving cavities are distributed on both sides of the air source distribution chamber (1-7). The outer walls adjacent to the left and right sides of the air source distribution chamber (1-7). The end faces of the air source distribution chamber (1-7) adjacent to the heat-preserving cavities are hermetically and fixedly connected. The outer surface of the outer wall of the connecting pipe is circumferentially and uniformly provided with air inlet channels (1-10). The inlet direction of the air inlet channels (1-10) is the same as the direction of the material conveying in the connecting pipe. The air inlet channels (1-10) are only in communication with the air source distribution chamber (1-7) and are not in communication with the heat-preserving cavities. The air source distribution chamber (1-7) is in communication with the in-line booster air source valve group (14) through an air inlet short pipe (3).

8. A pneumatic conveying system for hot direct reduced iron materials according to claim 7, characterized in that, The material of the connecting pipe is wear-resistant silicon carbide.

9. A pneumatic conveying system for hot direct reduced iron materials according to claim 1, characterized in that, The conveying pipeline (10) includes an inner wall (3-4) and an outer wall (3-2) of the conveying pipe. An adiabatic and heat-insulating material II (3-3) is filled between the inner wall (3-4) and the outer wall of the conveying pipe. The conveying pipeline (10) includes a plurality of horizontal gas conveying pipe segments and a plurality of vertical gas conveying pipe segments arranged along the material conveying direction. Adjacent horizontal gas conveying pipe segments are interconnected through wear-resistant elbows. The wear-resistant elbows are hermetically and fixedly connected to the end faces adjacent to the horizontal gas conveying pipe segments and the horizontal gas conveying pipe segments in pairs. The wear-resistant elbow includes an inner wall (5-4) and an outer wall (5-2) of the elbow. The outer wall (5-2) of the elbow is sleeved outside the inner wall (5-4) of the elbow. An adiabatic and heat-insulating material III (5-3) is filled between the inner wall (5-4) and the outer wall (5-2) of the elbow. The material of the inner wall (5-4) of the elbow is wear-resistant silicon carbide, and the material of the outer wall (5-2) of the elbow is 20# steel.

10. The pneumatic conveying system for hot direct reduced iron materials according to claim 1, characterized in that, The gas recovery device (23) includes a multi-tube water cooling device (2-4), a dust collector (2-5), a gas buffer tank (2-6), a conveying gas pressurizing device (2-7), and a conveying gas heating device (2-8) that are interconnected in sequence. The gas buffer tank (2-6) is also connected to a gas source supplement device (2-10) to continuously supplement nitrogen into the gas buffer tank (2-6).

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