Pulverized coal spray gun suitable for molten pool smelting process

Abstract

The utility model discloses a pulverized coal spray gun suitable for a molten pool smelting process, the pulverized coal spray gun sequentially comprises an oxygen-enriched outer pipe, an oxygen-enriched inner pipe and a pulverized coal pipe from outside to inside, and the center lines of the oxygen-enriched outer pipe, the oxygen-enriched inner pipe and the pulverized coal pipe are kept consistent; the tail end of the oxygen-enriched outer pipe is connected with a flow stabilizing chamber, the side, close to the flow stabilizing chamber, of the oxygen-enriched outer pipe is connected with a gas distribution main pipe, and the other end of the gas distribution main pipe is connected with a quick release connector; the middle part of the gas distribution main pipe is connected with a gas distribution branch pipe which is communicated with the flow stabilizing chamber; a flow limiting plug is arranged at the front end of the oxygen-enriched outer pipe, and a plurality of flow guide holes communicated with the outside are evenly formed in the flow limiting plug in the circumferential direction. A plurality of pressure balance holes are formed in the position, close to the flow limiting plug, of the front end of the oxygen-enriched inner pipe, and the pressure balance holes are evenly formed in the circumferential direction of a pipe body of the oxygen-enriched inner pipe. The structure of the spray gun is optimized, the spray gun is replaced during production, the production efficiency is greatly improved, and the labor intensity is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of metallurgical technology, specifically relating to a pulverized coal spray gun suitable for molten pool smelting process. Background Technology

[0002] The current mainstream pyrometallurgical processes mainly include flash smelting, top-blown smelting, side-blown pool smelting, and bottom-blown pool smelting. One of the most critical pieces of equipment in the side-blown or bottom-blown pool smelting process is the pool smelting lance. The effectiveness of the pool smelting lance and the replacement effectiveness directly affect the smelting effect and production efficiency. Currently, the pulverized coal lances used in the pyrometallurgical pool smelting industry have single-channel, dual-channel, and multi-channel structures, each with different advantages and disadvantages. Taking the currently mainstream two-channel and three-channel pulverized coal spray guns as examples, the two-channel plug-in pulverized coal spray gun (CN213515078U) overcomes the difficulty of gun changing operation and reduces the generation of nitrogen oxides, but sealing and airlocking are relatively difficult, and molten backflow is easy to occur when changing the spray gun. In addition, the pulverized coal pipe is made of stainless steel or manganese steel pipe, which has poor wear resistance and poses a safety risk. The three-channel pulverized coal spray gun (CN207180371U) is used to transport oxygen-enriched mixed gas, pulverized coal and nitrogen mixed components. Pulverized coal has a large surface area, complete combustion, and higher thermal efficiency than pure granulated coal. The limitation of this method is that the gun changing operation is difficult, nitrogen gas is blown into the molten pool to inhibit complete combustion, and nitrogen gas is blown into the high-temperature molten pool to a certain extent to increase the probability of nitrogen oxide generation.

[0003] It is evident that the aforementioned pulverized coal spray gun structures all exhibit varying degrees of design flaws when replacing the gun body, making it impossible to quickly replace the pulverized coal spray gun. Utility Model Content

[0004] In view of the problems existing in the above-mentioned background technology, this utility model provides a new type of pulverized coal spray gun suitable for molten pool smelting process, so as to realize the rapid replacement of pulverized coal spray gun and reduce the impact on production.

[0005] Therefore, the present invention adopts the following technical solution:

[0006] A pulverized coal spray lance suitable for molten pool smelting process includes, from the outside to the inside, an oxygen-enriched outer pipe, an oxygen-enriched inner pipe, and a pulverized coal pipe, with the centerlines of the three pipes aligned. A flow stabilizing chamber is connected to the tail end of the oxygen-enriched outer pipe, and a gas distribution main pipe is connected to the side of the outer pipe near the flow stabilizing chamber. A quick-release connector is connected to the other end of the gas distribution main pipe. A gas distribution branch pipe is connected to the middle of the gas distribution main pipe and communicates with the flow stabilizing chamber. One end of the flow stabilizing chamber is connected to the oxygen-enriched inner pipe, and the other end is fixed to a connecting base. A pulverized coal receiving seat is detachably connected to the connecting base, and the pulverized coal receiving seat is sealed to the pulverized coal pipe penetrating the flow stabilizing chamber. A flow-limiting plug is provided at the front end of the oxygen-enriched outer pipe, and multiple guide holes communicating with the outside are evenly arranged circumferentially on the plug. Multiple pressure balancing holes are opened at the front end of the oxygen-enriched inner pipe near the flow-limiting plug, and these holes are evenly arranged circumferentially along the inner pipe.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] 1. The spray gun adopts an integrated three-channel design, which can simultaneously transport combustion air and pulverized coal, and can quickly replace the spray gun. At the same time, it can avoid backflow of molten material when replacing the spray gun, thus avoiding the operation steps of lowering the liquid level required in the past.

[0009] 2. The pulverized coal pipe is designed with a certain thickness of high temperature and wear-resistant single-layer material such as 316L or 16Mn, or with a double-layer structure of high temperature resistant material on the outer layer such as 304 or 315B and wear-resistant and high temperature resistant material such as ceramic pipe, to ensure improved wear resistance to solid fuel. The pulverized coal pipe and the pulverized coal pipe socket are connected by threads, which facilitates quick replacement of the pulverized coal pipe.

[0010] 3. The oxygen-enriched inner pipe is equipped with a pressure balance hole. At the moment the inner pulverized coal pipe is withdrawn, a portion of the combustion air from the outermost channel quickly enters the middle channel through the pressure balance hole, ensuring the pressure in the middle channel and preventing the melt from backflowing and clogging the spray gun.

[0011] 4. When the spray gun is inserted into the slag layer, the molten slag does not corrode the spray gun. The main damage is caused by high-temperature burning. Since the spray gun is cooled by high-speed airflow, high-temperature burning can be avoided, which can ensure the service life of the outer tube of the spray gun. Only the pulverized coal tube is gradually worn by the scouring of pulverized coal particles. The pulverized coal tube can be replaced.

[0012] In summary, this utility model optimizes the spray gun structure, enabling spray gun replacement during production, which significantly improves production efficiency and reduces labor intensity. Attached Figure Description

[0013] Figure 1 This is a front structural cross-sectional view of the pulverized coal spray gun described in this utility model.

[0014] Figure 2 for Figure 1 Enlarged view of the left-side structure.

[0015] Figure 3 for Figure 1 Enlarged view of the right-side structure.

[0016] In the diagram, 1-gas distribution main pipe, 2-oxygen-enriched outer pipe, 3-oxygen-enriched inner pipe, 4-pulverized coal pipe, 5-pressure balance hole, 6-quick-release connector, 7-flow stabilizing chamber, 8-guide groove, 9-air lock plate, 10-limiting column, 11-gas distribution branch pipe, 12-connecting base, 13-pulverized coal receiving seat, 14-flow guide hole. Detailed Implementation

[0017] The present invention will be further explained below with reference to the accompanying drawings.

[0018] like Figure 1-3 As shown, a pulverized coal spray gun suitable for molten pool smelting process includes, from the outside to the inside, an oxygen-enriched outer pipe 2, an oxygen-enriched inner pipe 3, and a pulverized coal pipe 4, with the center lines of the oxygen-enriched outer pipe 2, oxygen-enriched inner pipe 3, and pulverized coal pipe 4 aligned. A flow stabilizing chamber 7 is connected to the tail end of the oxygen-enriched outer pipe 2, and a gas distribution main pipe 1 is connected to the side of the oxygen-enriched outer pipe 2 near the flow stabilizing chamber 7. A quick-release connector 6 is connected to the other end of the gas distribution main pipe 1. A gas distribution branch pipe 11 with a diameter smaller than the gas distribution main pipe is connected to the middle of the gas distribution main pipe 1, and the gas distribution branch pipe 11 communicates with the flow stabilizing chamber 7. One end of the flow chamber 7 is connected to the oxygen-enriched inner pipe 3 and a guide groove 8 with a gradually decreasing diameter is provided at the connection. The other end is fixed with a connecting base 12. A pulverized coal receiving seat 13 is detachably connected to the connecting base 12. The pulverized coal receiving seat 13 is sealed to the pulverized coal pipe 4 that passes through the flow chamber 7. A flow-limiting plug is provided at the front end of the oxygen-enriched outer pipe 2. Multiple guide holes 14 communicating with the outside are evenly arranged along the circumference of the flow-limiting plug. Multiple pressure balance holes 5 are opened at the front end of the oxygen-enriched inner pipe 3 near the flow-limiting plug. The pressure balance holes 5 are evenly arranged along the circumference of the body of the oxygen-enriched inner pipe 3.

[0019] An air lock plate 9 is hinged to the inner wall of the flow stabilizing chamber 7. The air lock plate 9 is located below the outlet of the gas distribution branch pipe 11, and the free end of the air lock plate 9 overlaps the pulverized coal pipe 4. A limit post 10 is also provided above the air lock plate 9 near the outlet of the gas distribution branch pipe 11.

[0020] In the above structure, the pulverized coal pipe 4 and the pulverized coal receiving seat 13 are connected by threads. Since the pulverized coal pipe is a component with high wear and high replacement frequency, this can improve the replacement efficiency, increase the reuse rate of other components, and reduce the cost of use.

[0021] The inside of the flow stabilizing chamber 7 is designed with a guide groove 8 at the outlet end, which can ensure that the pulverized coal pipe is automatically slid into the oxygen-enriched inner pipe 3 through the guide groove when it is inserted, preventing jamming, avoiding the need for precise positioning of personnel during insertion, and improving the insertion speed.

[0022] There is an annular gap between the oxygen-enriched inner pipe 3 and the pulverized coal pipe 4. Compressed air or oxygen-enriched air is ejected at high speed from the annular gap, which can quickly cool the head of the pulverized coal pipe and extend its service life.

[0023] The pressure balance hole 5 is mainly elliptical in shape. Its principle is to allow the air in the outer channel and the middle channel to be connected to each other and maintain pressure balance. More importantly, at the moment when the pulverized coal pipeline is slowly pulled out, compressed air or oxygen-enriched air enters the inner pipe position from the middle pipe instantly, and the back pressure of the air holds the molten material in place, preventing the molten material from flowing back.

[0024] In the process of using this utility model, firstly, during normal production, the pulverized coal spray gun is inserted into the furnace through the spray gun hole in the furnace wall. The spray gun head generally protrudes 10mm~50mm from the inner side of the wall. The oxygen-enriched air metal hose and the pulverized coal ceramic hose are respectively connected to the quick-release connector 6 and the pulverized coal receiving seat to supply oxygen-enriched air and pulverized coal. The oxygen-enriched air is divided into two airflows with different airflow volumes from the gas distribution main pipe 1. The oxygen-enriched air with a larger airflow volume enters through the gas distribution main pipe 1, flows into the oxygen-enriched outer pipe 2, and is sprayed into the furnace after the flow velocity is increased by the guide hole 14. The oxygen-enriched air with a smaller airflow volume enters the flow stabilization chamber 7 through the gas distribution branch pipe 11 and is sprayed into the furnace through the oxygen-enriched inner pipe 3. The oxygen-enriched outer pipe 2 and the oxygen-enriched inner pipe 3 maintain the consistency of the internal and external air pressure through the pressure balance hole 5. Pulverized coal is sprayed into the furnace from the pulverized coal pipe 4 under a certain pressure. It reacts with the oxygen-enriched air in the area in front of the spray gun to provide the required heat for the melt. Excess oxygen-enriched air undergoes a strong oxidation smelting reaction with the melt, and excess pulverized coal undergoes a strong reduction smelting reaction with the melt.

[0025] The pulverized coal pipe replacement operation involves replacing the pulverized coal pipe 4 after a period of use, as pulverized coal is a solid particle and causes significant wear. Before replacement, the pulverized coal source in the pulverized coal conveying pipe is shut off, while the pulverized coal conveying air (carrying air) is retained. The conveying air is generally nitrogen or compressed air. Then, the pulverized coal receiving seat 13 is removed, and the pulverized coal pipe 4 is slowly pulled out. Once the head of the pulverized coal pipe 4 exceeds the pressure balance hole 5, some of the oxygen-enriched air in the oxygen-enriched outer pipe 2 quickly enters the oxygen-enriched inner pipe 3 through the pressure balance hole 5 to form a new balance. Then, the pulverized coal pipe 4 is quickly pulled out. At the moment the pulverized coal pipe 4 is pulled out, the air-locking plate 9 in the flow stabilizing chamber 7 rotates under its own weight and the pressure of the oxygen-enriched air, covering the inner end face of the connecting base 12, thus preventing the oxygen-enriched air from leaking back. After pulling out the pulverized coal pipe, the conveying air is shut off, completing the pulverized coal pipe removal operation. The operator removes the damaged pulverized coal pipe 4 from the pulverized coal receiving seat 13, replaces it with a brand new pulverized coal pipe, then turns on the conveying air and quickly inserts the pulverized coal pipe 4 through the opening in the middle of the base. During the insertion process, the air lock plate 9 is first pushed open, and the air lock plate stops at the limiting post 10 to avoid blocking the air outlet. Then the pulverized coal pipe 4 is inserted into the oxygen-enriched inner pipe 3 through the guide groove 8, and after passing through the pressure balance hole 5, a ring gap is formed again until it reaches the nozzle. Then the pulverized coal receiving seat 13 is reinstalled, the pulverized coal conveying is turned on, and the replacement operation of the pulverized coal pipe 4 is completed.

[0026] For complete replacement of the spray gun, a spray gun replacement device (ZL202223174006.X) must be installed beforehand. Before pulling out the spray gun, open the protective air (usually compressed air) of the spray gun replacement device, shut off the pulverized coal conveying pipeline, and then pull out the entire spray gun. The airlock device inside the spray gun replacement device will instantly close. Then, shut off the oxygen-enriched air and conveying air of the spray gun, and replace the spray gun barrel with a new one. After the barrel replacement is complete, open the oxygen-enriched air and conveying air, insert the spray gun into the spray gun replacement device until it reaches its original position inside the furnace wall, close the protective air of the spray gun replacement device, and open the valve of the pulverized coal conveying pipeline to complete the complete spray gun replacement operation.

[0027] This ensures that, whether replacing the pulverized coal nozzle or replacing the entire nozzle, the molten material inside the furnace cannot enter the device after the nozzle is pulled out. This allows users to complete the replacement smoothly while the nozzle is below the molten material surface, without having to lower the liquid level to expose the nozzle. This avoids system shutdown for liquid level lowering operations, enabling nozzle replacement during normal production. It simplifies the nozzle replacement process, eliminates the impact on production, greatly facilitates user operation, and improves operating efficiency.

Claims

1. A pulverized coal injection lance suitable for use in a smelt bath smelting process, characterized in that, The pulverized coal spray gun consists of an oxygen-enriched outer pipe (2), an oxygen-enriched inner pipe (3), and a pulverized coal pipe (4) from the outside to the inside, and the center lines of the oxygen-enriched outer pipe (2), the oxygen-enriched inner pipe (3), and the pulverized coal pipe (4) are aligned. The tail end of the oxygen-enriched outer pipe (2) is connected to a flow stabilizing chamber (7), and a gas distribution main pipe (1) is connected to the side of the oxygen-enriched outer pipe (2) near the flow stabilizing chamber (7). The other end of the gas distribution main pipe (1) is connected to a quick-release connector (6). A gas distribution branch pipe (11) is connected to the middle of the gas distribution main pipe (1), and the gas distribution branch pipe (11) is connected to the flow stabilizing chamber (7). The flow stabilizing chamber... (7) One end is connected to the oxygen-enriched inner pipe (3), and the other end is fixed with a connecting base (12). A pulverized coal receiving seat (13) is detachably connected to the connecting base (12). The pulverized coal receiving seat (13) is sealed to the pulverized coal pipe (4) that passes through the flow stabilizing chamber (7). A flow-limiting plug is provided at the front end of the oxygen-enriched outer pipe (2). Multiple flow-guiding holes (14) that communicate with the outside are uniformly arranged along the circumference of the flow-limiting plug. Multiple pressure balance holes (5) are opened at the front end of the oxygen-enriched inner pipe (3) near the flow-limiting plug. The pressure balance holes (5) are uniformly arranged along the circumference of the body of the oxygen-enriched inner pipe (3).

2. A pulverized coal injection lance suitable for use in a smelt reduction process as claimed in claim 1, wherein, The diameter of the main gas distribution pipe (1) is larger than that of the branch gas distribution pipe (11).

3. A pulverized coal injection lance suitable for use in a smelt reduction process as claimed in claim 1, wherein, A guide groove (8) with a gradually decreasing diameter is provided at the connection between the flow stabilizing chamber (7) and the oxygen-enriched inner tube (3).

4. A pulverized coal injection lance suitable for use in a smelt reduction process as claimed in claim 1, wherein, A lock plate (9) is hinged to the inner wall of the flow stabilizing chamber (7). The lock plate (9) is located below the outlet of the gas distribution branch pipe (11), and a limit post (10) is provided above the lock plate (9) near the outlet of the gas distribution branch pipe (11).

5. The pulverized coal injection lance suitable for molten pool smelting process as described in claim 4, characterized in that, The free end of the airlock plate (9) overlaps on the pulverized coal pipe (4).

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