Membrane type water-cooled wall flash ironmaking device

Abstract

The utility model discloses a membrane type water-cooled wall flash ironmaking device, and belongs to the technical field of green low-carbon environment-friendly metallurgy. The device is a coal gasification flash ironmaking device, the lower part of the device is an elliptical or rectangular molten pool, the left upper part of the molten pool is a flash smelting furnace, the right upper part of the molten pool is a gravity settling chamber, and the flash smelting furnace, the molten pool and the gravity settling chamber are all provided with membrane water-cooled wall structures. According to the device provided by the utility model, the refractory material can be effectively protected, and the service life of the flash smelting furnace is prolonged; natural circulation of cooling water of the water-cooled wall of the iron-making furnace is realized, and power consumption is reduced; the membrane type water cooling wall structure protects the refractory material and produces steam at the same time, waste heat recovery of cooling water is achieved, and the dust content in ironmaking tail gas is greatly reduced.

Description

Technical Field

[0001] This utility model specifically relates to a membrane water-cooled wall flash ironmaking device, which belongs to the field of green, low-carbon and environmentally friendly metallurgical technology. Background Technology

[0002] Both blast furnace ironmaking and flash copper smelting utilize stacked water-cooled walls, which protect refractory materials, extend their service life to prolong furnace life, and reduce ironmaking production costs. Chinese patent CN102690919A discloses a flash metallurgical method for iron, involving water-cooled protection of refractory bricks in a flash metallurgical furnace: "The refractory bricks are protected by embedding copper water jackets or water-cooled walls, or by setting up open-water water-cooled protection devices," intended to protect the refractory materials. Traditional water-cooled walls are all stacked water-cooled walls, which have the following problems: First, their material is cast iron, cast steel, or cast copper, resulting in high costs; second, forced circulation in a single stack leads to high power consumption; and third, forced heat dissipation from hot water prevents waste heat recovery. Utility Model Content

[0003] To address the aforementioned problems, this invention proposes a membrane water-cooled wall flash ironmaking device. The membrane water-cooled wall not only effectively protects refractory materials but also utilizes its unique structure to achieve natural circulation of cooling water, reducing power consumption. This invention is highly suitable for the development of green and low-carbon metallurgical technologies.

[0004] Membrane water-cooled walls are a type of water-cooled wall structure used in circulating fluidized bed boilers. Integrating and transplanting them into coal gasification flash smelting furnaces requires significant technological innovation based on the process conditions of flash ironmaking and molten pool ironmaking, representing a major technological advancement. Utilizing the membrane water-cooled wall structure, steam is produced while protecting the refractory materials, achieving waste heat recovery from the cooling water.

[0005] This utility model provides a membrane water-cooled wall flash ironmaking device, which is a coal gasification flash ironmaking device. Its lower part is an elliptical or rectangular molten pool, the upper left part of the molten pool is a flash smelting furnace, and the upper right part is a gravity settling chamber. The flash smelting furnace, the molten pool and the gravity settling chamber are all equipped with water-cooled walls, and the water-cooled walls are all membrane water-cooled wall structures.

[0006] In the aforementioned device, the membrane water-cooled wall is an airtight tube-screen water-cooled wall with alternating flat steel fins and water pipes. An upper header and a lower header are welded to the upper and lower ends of the airtight tube screen, respectively. The upper header is connected to the steam drum via an outlet pipe. The steam drum has a demineralized water inlet and a steam outlet. A downcomer is connected to the lower part of the steam drum, and the downcomer is connected to the lower header. The airtight tube-screen water-cooled wall has a circular or square structure. Specifically, the downcomer on the steam drum is connected to the lower header of the flash section, the lower header of the molten pool, and the lower header of the settling chamber, respectively. These are connected to the upper header of the flash section, the upper header of the molten pool, and the upper header of the settling chamber via water pipes from the membrane water-cooled wall tube screen. The upper header of the flash section, the upper header of the molten pool, and the upper header of the settling chamber are connected to the steam drum via outlet pipes, forming a circulating water system.

[0007] In the aforementioned apparatus, the flat steel fins of the flash smelting furnace are welded with catch pins facing the fire, and the water pipes are welded with pins facing the fire. A refractory layer is cast on the catch pins and pins. The refractory layer is a silicon carbide layer (composed of silicon carbide refractory material) or a composite layer of chromium oxide and alumina (composed of chromium oxide and alumina refractory material). The thickness of the refractory layer cast in the flash smelting furnace is 6-15 cm.

[0008] In the above-mentioned device, the flat steel fins of the membrane water-cooled wall of the molten pool are welded with grab studs to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. A refractory layer is poured on the entire membrane water-cooled wall and its pins and grab studs, and high-chromium refractory bricks are laid on the fire-facing side of the poured refractory layer.

[0009] In the above-mentioned device, the flat steel fins of the membrane water-cooled wall of the gravity settling chamber are welded with grab pins to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. A thermally conductive silicon carbide or silicon-aluminum refractory layer is poured on the membrane water-cooled wall and its pins and grab pins, and the thickness of the refractory layer is 3 to 6 cm.

[0010] In the aforementioned device, a high-temperature gas outlet is provided at the top of the gravity settling chamber.

[0011] In the above-mentioned device, several copper water jackets and spray guns are installed on the side wall of the molten pool. The copper water jackets have spray gun insertion holes in the middle, into which gas and powder multi-channel spray guns are inserted.

[0012] In the aforementioned apparatus, a base plate is welded to the lower part of the lower header of the molten pool water-cooled wall. The base plate is made of steel plate, and the inner side of the steel plate facing the fire (i.e., the bottom of the molten pool) is constructed of refractory bricks. Bottom cooling pipes are laid beneath the steel plate. These cooling pipes can be water cooling pipes, air cooling pipes, or cooling pipes containing other media such as nitrogen or carbon dioxide gas. Several bottom cooling pipes are evenly arranged under the bottom plate of the molten pool.

[0013] In the aforementioned apparatus, the diameter of the airtight tube screen of the molten pool membrane water-cooled wall is larger than the diameter of the airtight tube screen of the flash smelting section membrane water-cooled wall.

[0014] The outer side of the lower header of the flash furnace membrane water-cooled wall and the top of the upper header of the molten pool are welded together by a metal expansion joint. The inner side of the lower header has 30-70 cm long heat-resistant steel fins welded downwards. The inner side of the fins has studs welded to the fire surface, and a refractory layer is cast on the studs. The length of the fins is the same as the length of the metal expansion joint, and the space between the fins and the metal expansion joint is filled with alumina or zirconia refractory fiber felt. A labyrinth seal structure is used between the lower part of the fins and the metal expansion joint.

[0015] In the aforementioned apparatus, the top of the upper header of the flash furnace is connected to the conical flat-top head via a flange, forming a complete airtight structure for the membrane water-cooled wall flash ironmaking device. The conical flat-top head has a refractory layer cast or laid on the fire side; a burner for pulverized coal, oxygen, and iron ore powder is installed at the center of the conical flat-top head; the burner can be an integrated three-channel burner or a separate burner.

[0016] The connection between the flash furnace and the bottom of the gravity settling chamber is the top of the molten pool. The inner wall is connected by water-cooled refractory lining, and the entire furnace body forms a closed structure.

[0017] In the aforementioned device, the membrane water-cooled wall flash furnace has a steel frame suspension device welded to the outside of the airtight pipe screen under the upper header to suspend and fix the flash furnace body. The outside of the flash furnace body is also provided with a guide and anti-sway structure to stabilize the furnace body.

[0018] In the aforementioned apparatus, the molten pool has an iron outlet and a slag outlet. The diameter of the gravity settling chamber is 40-60% larger than that of the flash furnace.

[0019] The beneficial effects of this utility model are:

[0020] (1) It can effectively protect refractory materials;

[0021] (2) It realizes the natural circulation of cooling water in the water-cooled wall, reducing power consumption;

[0022] (3) By utilizing membrane water-cooled walls to produce steam while protecting refractory materials, waste heat recovery of cooling water is achieved.

[0023] (4) The dust content in the ironmaking tail gas is greatly reduced by utilizing the settling effect of the gravity settling chamber. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the membrane water-cooled wall flash ironmaking device of this utility model.

[0025] In the diagram: 1 is the burner, 2 is the conical flat-top head, 3 is the flash furnace, 4 is the refractory layer, 5 is the heat-resistant steel fins, 6 is the steam drum, 7 is the downcomer, 8 is the lower header of the flash section, 9 is the membrane water-cooled wall of the flash section, 10 is the upper header of the flash section, 11 is the outlet pipe, 12 is the steel frame suspension device, 13 is the guide and anti-sway structure, 14 is the metal expansion joint, 15 is the high-temperature resistant packing, 16 is the molten pool, 17 is the refractory layer of the molten pool, and 18 is... 19 is the lower header of the molten pool, 20 is the membrane water-cooled wall of the molten pool, 21 is the upper header of the molten pool, 22 is the steel shell of the molten pool, 23 is the copper water jacket and spray gun, 24 is the slag outlet, 25 is the molten iron outlet, 26 is the bottom cooling pipe of the pool, 27 is the gravity settling chamber, 28 is the refractory layer of the settling chamber, 29 is the lower header of the settling chamber, 30 is the membrane water-cooled wall of the settling chamber, 31 is the gas outlet, 32 is the bottom plate of the molten pool, and 33 is the high-chromium refractory brick. Detailed Implementation

[0026] The present invention will be further illustrated by the following embodiments, but is not limited to the following embodiments. Example

[0027] This utility model provides a membrane water-cooled wall flash ironmaking device, which is a coal gasification flash ironmaking device. Its lower part is an elliptical or rectangular molten pool 16, the upper left part of the molten pool is a flash furnace 3, and the upper right part is a gravity settling chamber 26. Water-cooled walls are provided in the flash furnace 3, the molten pool 16, and the gravity settling chamber 26. All water-cooled walls are membrane water-cooled wall structures. Figure 1 The flash section membrane water-cooled wall 9, the molten pool membrane water-cooled wall 19, and the settling chamber membrane water-cooled wall 29 are shown in the diagram.

[0028] In the aforementioned device, the membrane water-cooled wall is an airtight tube-screen water-cooled wall with flat steel fins and water pipes welded alternately. An upper header and a lower header are welded to the upper and lower ends of the airtight tube screen, respectively. The upper header is connected to the steam drum 6 via an outlet pipe 11. The steam drum has a demineralized water inlet and a steam outlet. A downcomer 7 is connected to the lower part of the steam drum 6, and the downcomer 7 is connected to the lower header. The airtight tube-screen water-cooled wall has a circular or square structure. Specifically, the downcomer 7 on the steam drum is connected to the flash section lower header 8, the molten pool lower header 18, and the settling chamber lower header 28, respectively. These are connected to the flash section upper header 10, the molten pool upper header 20, and the settling chamber upper header 30, respectively, via water pipes from the membrane water-cooled wall tube screen. The flash section upper header 10, the molten pool upper header 20, and the settling chamber upper header 30 are connected to the steam drum 6 via outlet pipes 11, forming a circulating water system.

[0029] In the aforementioned apparatus, the flat steel fins of the flash smelting furnace are welded with catch pins facing the fire, and the water pipes are welded with pins facing the fire. A refractory layer 4 is cast on the catch pins and pins. The refractory layer is a silicon carbide layer (composed of silicon carbide refractory material) or a composite layer of chromium oxide and alumina (composed of chromium oxide and alumina refractory material). The thickness of the refractory layer of the flash smelting furnace is 6-15 cm.

[0030] In the above-mentioned device, the flat steel fins of the membrane water-cooled wall of the molten pool are welded with grab pins to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. The entire membrane water-cooled wall and its pins and grab pins are poured with a molten pool refractory layer 17, and the inner side of the molten pool refractory layer 17 is lined with high-chromium refractory bricks 33.

[0031] In the above-mentioned device, the flat steel fins of the membrane water-cooled wall of the gravity settling chamber are welded with grab pins to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. A thermally conductive silicon carbide or silicon-aluminum refractory layer is poured on the membrane water-cooled wall and its pins and grab pins, and the thickness of the refractory layer is 3 to 6 cm.

[0032] In the aforementioned device, a high-temperature gas outlet 31 is provided at the top of the gravity settling chamber 26.

[0033] In the above-mentioned device, several copper water jackets and spray guns 22 are installed on the side wall of the molten pool. The copper water jackets have spray gun insertion holes in the middle, into which gas and powder multi-channel spray guns are inserted.

[0034] In the aforementioned apparatus, a bottom plate 32 of the molten pool is welded to the lower part of the lower header 18. The bottom plate is made of steel plate, and the inner side of the steel plate facing the fire (i.e., the bottom of the molten pool) is constructed of refractory bricks. Bottom cooling pipes 25 are laid beneath the steel plate. These cooling pipes can be water cooling pipes, air cooling pipes, or cooling pipes containing other media such as nitrogen or carbon dioxide gas. Several bottom cooling pipes 25 are evenly arranged below the bottom plate 32 of the molten pool.

[0035] In the above-mentioned device, the diameter of the airtight tube screen of the molten pool membrane water-cooled wall 19 is larger than the diameter of the airtight tube screen of the flash smelting section membrane water-cooled wall 9.

[0036] The outer side of the lower header of the flash furnace membrane water-cooled wall and the top of the upper header of the molten pool are welded together by a metal expansion joint 14. A 30-70 cm long heat-resistant steel fin 5 is welded downwards to the inner side of the lower header. A catch pin is welded to the inner side of the fin facing the fire surface, and a refractory layer is cast on the catch pin. The length of the heat-resistant steel fin 5 is the same as the length of the metal expansion joint 14. A high-temperature resistant filler 15 is provided between the heat-resistant steel fin 5 and the metal expansion joint; specifically, the filler is alumina or zirconia refractory fiber felt. A labyrinth seal structure is formed between the lower part of the heat-resistant steel fin and the metal expansion joint.

[0037] In the aforementioned device, the top of the flash section upper header 10 is connected to the conical flat-top head 2 via a flange, forming a complete airtight structure for the membrane water-cooled wall flash ironmaking device. The conical flat-top head 2 has a refractory layer 4 cast or laid on the fire side; a burner 1 for pulverized coal, oxygen, and iron ore powder is installed at the center of the conical flat-top head; the burner can be an integrated three-channel burner or a separate burner.

[0038] The connection between the flash furnace and the bottom of the gravity settling chamber is the top of the molten pool. The inner wall is connected by water-cooled refractory lining, and the entire furnace body forms a closed structure.

[0039] In the above-mentioned device, the membrane water-cooled wall flash furnace has a steel frame suspension device 12 welded to the outside of the airtight pipe screen under the upper header to suspend and fix the flash furnace body. The flash furnace body is also provided with a guide anti-sway structure 13 to stabilize the furnace body.

[0040] In the aforementioned apparatus, the molten pool has an iron outlet 24 and a slag outlet 23. The diameter of the gravity settling chamber 26 is 50% larger than the diameter of the flash furnace.

[0041] The operation method of the above-mentioned membrane water-cooled wall flash ironmaking unit is as follows:

[0042] The water system operates as follows: When the flash furnace enters the smelting preparation phase, demineralized water is pumped into the steam drum 6 through the inlet. From the downcomer 7 on the steam drum, the water flows through the lower header 8 of the flash section, the lower header 18 of the molten pool, and the lower header 28 of the settling chamber, entering the water pipes of the membrane water-cooled wall tube screen and remaining full. When the flash furnace enters the flash smelting operation, as the furnace temperature increases, the water in the water-cooled wall is heated while cooling the refractory material. Water and steam rise along the tube screen riser, passing through the upper header 10 of the flash section, the upper header 20 of the molten pool, and the upper header 30 of the settling chamber, before entering the steam drum 6 through the outlet pipe 11. After steam-water separation, the steam is discharged through the steam outlet on the steam drum, while the water flows down along the downcomer 7, passing through each lower header and re-entering the respective tube screen riser, forming a natural water-steam circulation process. During this process, excess heat is carried away from the refractory materials of the flash furnace wall, molten pool wall, and settling chamber wall, and steam is produced.

[0043] The slag operation method in a flash furnace: When pulverized coal and iron ore powder are smelted at temperatures above 1500°C in the flash furnace and splash onto the refractory layer of the furnace wall, as heat is transferred out through the water-cooled wall, the furnace wall temperature is lower than the slag's freezing point. The molten slag solidifies on the furnace wall from a molten state to a solid state. As the solidified layer thickens, heat transfer decreases, and the temperature is higher than the slag's freezing point. The slag, in liquid form, flows down the solidified layer along the furnace wall into the molten pool.

[0044] The operation method of the molten pool is as follows: a copper water jacket and a spray gun are installed at a certain height in the molten pool; when the spray gun needs to be replaced due to wear, the slag and iron liquid level is lowered below the spray gun position through the slag and iron outlets, and after the spray gun is replaced, the slag and iron liquid level is raised again to allow the molten pool to enter the normal operation process.

[0045] The operation method of the flash furnace is as follows: the upper part of the flash furnace is a fixed end, and the lower part is a free end. When heated and expanded, it extends and contracts downwards; that is, when the flash furnace is heated and expanded during the normal smelting process, it extends downwards freely.

[0046] The operation of the gravity settling chamber is primarily driven by airflow. The upward airflow velocity in the settling chamber is approximately 50% lower than the downward airflow velocity in the flash furnace. The settling chamber structure itself expands and contracts upwards when heated.

Claims

1. A membrane-type water-cooled wall flash ironmaking device, which is a coal gasification flash ironmaking device, wherein the lower part is an elliptical or rectangular molten pool, the upper left part of the molten pool is a flash smelting furnace, and the upper right part is a gravity settling chamber, characterized in that: The flash smelting furnace, molten pool, and gravity settling chamber are all equipped with water-cooled walls, all of which are membrane-type water-cooled wall structures. The membrane-type water-cooled wall is an airtight tube screen water-cooled wall with flat steel fins and water pipes welded alternately. An upper header and a lower header are welded to the upper and lower ends of the airtight tube screen, respectively. The upper header is connected to the steam drum through an outlet pipe. The steam drum has a demineralized water inlet and a steam outlet. The lower part of the steam drum is connected to a downcomer, which is connected to the lower header. The airtight tube screen water-cooled wall has a circular or square structure.

2. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The flat steel fins of the flash smelting furnace are welded with catch nails to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. A refractory layer is cast on the catch nails and pins. The refractory layer is a silicon carbide layer or a composite layer of chromium oxide and aluminum oxide. The thickness of the refractory layer of the flash smelting furnace is 6-15 cm.

3. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The flat steel fins of the membrane water-cooled wall of the molten pool are welded with catch nails to the fire-facing side, and the water pipes are welded with pins to the fire-facing side. A refractory layer is poured on the entire membrane water-cooled wall and its pins and catch nails, and high-chromium refractory bricks are laid on the fire-facing side of the poured refractory layer.

4. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The flat steel fins of the membrane water-cooled wall of the gravity settling chamber are welded with catch nails on the fire-facing side, and the water pipes are welded with pins on the fire-facing side. A thermally conductive silicon carbide or silicon-aluminum refractory layer is poured on the membrane water-cooled wall and its pins and catch nails. The thickness of the refractory layer is 3 to 6 cm.

5. The membrane water-cooled wall flash ironmaking device according to claim 4, characterized in that: The gravity settling chamber has a high-temperature gas outlet at the top.

6. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: Several copper water jackets and spray guns are installed on the side wall of the molten pool. The copper water jackets have spray gun insertion holes in the middle, into which multi-channel spray guns for gas and powder are inserted. The molten pool has an iron outlet and a slag outlet. The lower part of the water-cooled wall header of the molten pool is welded with a bottom plate. The bottom plate is made of steel plate, and the inner side of the steel plate facing the fire is made of refractory bricks. The bottom cooling pipes are laid under the steel plate. The cooling pipes are one of water cooling pipes, air cooling pipes, nitrogen gas cooling pipes, and carbon dioxide gas cooling pipes. Several bottom cooling pipes are evenly arranged under the bottom plate of the molten pool.

7. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The diameter of the airtight tube screen of the molten pool membrane water-cooled wall is larger than the diameter of the airtight tube screen of the flash smelting section membrane water-cooled wall; the diameter of the gravity settling chamber is 40-60% larger than the diameter of the flash furnace.

8. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The outer side of the lower header of the flash furnace membrane water-cooled wall and the top of the upper header of the molten pool are welded together by a metal expansion joint; the inner side of the lower header of the flash furnace membrane water-cooled wall has 30-70 cm long heat-resistant steel fins welded downwards, and the inner side of the fins is welded to the fire surface with a refractory layer cast on the fins; the length of the fins is the same as the length of the metal expansion joint, and alumina or zirconia refractory fiber felt is provided between the fins and the metal expansion joint; the lower part of the fins and the metal expansion joint have a labyrinth seal structure.

9. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: The top of the upper header of the flash smelting furnace is connected to the conical flat-top head via a flange. The conical flat-top head is cast or lined with a refractory layer on the fire side. A burner for pulverized coal, oxygen, and iron ore powder is installed in the center of the conical flat-top head. The burner is an integrated three-channel burner or a separate burner.

10. The membrane water-cooled wall flash ironmaking device according to claim 1, characterized in that: A steel frame suspension device is welded to the outside of the airtight pipe screen below the upper header of the flash smelting furnace to suspend and fix the furnace body. A guide anti-sway structure is also provided on the outside of the furnace body to stabilize the furnace body.

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