Molten iron waste heat utilization structure

Abstract

The utility model discloses a structure for utilizing waste heat of molten iron, and relates to the technical field of waste heat recovery and utilization in metallurgical processes. The structure includes an ironmaking trench cover, an air collecting box, and a blast furnace bunker; the ironmaking trench cover includes a cover plate and a heat exchange tube, a mounting groove is provided inside the cover plate, and the heat exchange tube is coiled in the mounting groove; a dust removal filter is installed at one end of the heat exchange tube, and a hot air duct is externally connected to the other end of the heat exchange tube, and the hot air duct is collected to the air collecting box, the air collecting box is connected to the inlet of the hot air blower, and the outlet of the hot air blower is connected to the blast furnace bunker through a pipeline and a drying preheater. In the structure, a heat exchange tube is placed inside the ironmaking trench cover, and a dust removal filter is installed at the inlet end of the heat exchange tube. The dust removal filter filters and removes dust in the air, and the dust enters the heat exchange tube and is heated by the radiant heat of the iron trench, and then is collected in the air collecting box. The heated air is transported to the bunker through a pipeline to bake and preheat the charge entering the blast furnace bunker, so as to avoid moisture in the charge during the rainy season and improve the dryness and temperature of the charge entering the blast furnace.

Description

Technical Field

[0001] The utility model relates to the technical field of waste heat recovery and utilization in metallurgical processes, in particular to a molten iron waste heat utilization structure. Background Art

[0002] The blast furnace taphole is an important thermal energy part of the ironmaking system. The taphole is used to transport a mixture of high-temperature molten iron and slag out of the blast furnace. It is the position where the molten iron has the highest temperature after it leaves the furnace. The heat energy here is high-temperature radiant heat. The taphole or taphole structures disclosed in existing patents are mostly for insulation functions to reduce heat loss, and few of them recycle radiant heat.

[0003] Publication No. CN114774603A discloses a system for recycling high-temperature radiant heat from a blast furnace tapping channel, comprising a channel cover heat exchange plate with a heat exchange tube inside, cold air ducts and hot air ducts on both sides of the channel cover heat exchange plate, the hot air duct is connected to the blast furnace combustion-supporting air duct, the cold air duct is connected to the cold air inlet of the heat exchange tube, and the cold air is supplied by a fan and passed into the heat exchange tube of the channel cover heat exchange plate. Although this system recycles the radiant heat from the iron channel, the carrier cold air is fed by the fan, which increases the equipment cost and power consumption. At the same time, the charge is easily damp and agglomerated in summer, which seriously affects the smelting effect. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a molten iron waste heat utilization structure, which does not require additional cold air, uses natural wind as a heat exchange carrier, and transports the high-temperature radiant heat of the molten iron ditch to the silo to dry the charge.

[0005] To achieve this technical purpose, the utility model adopts the following scheme: a molten iron waste heat utilization structure, including an ironmaking trench cover, an air collecting box and a blast furnace silo; the ironmaking trench cover includes a cover plate and a heat exchange tube, an installation groove is opened inside the cover plate, and the heat exchange tube is coiled in the installation groove; a dust removal filter is installed at one end of the heat exchange tube, and the other end of the heat exchange tube is externally connected to a hot air duct, and the hot air duct is gathered to the air collecting box, the air collecting box is connected to the hot air blower inlet, and the hot air blower outlet is connected to the blast furnace silo through a pipeline and a drying preheater.

[0006] Compared with the prior art, the beneficial effect of the utility model is that: the structure places a heat exchange tube inside the ironmaking trench cover, and installs a dust removal filter at the inlet end of the heat exchange tube. The dust removal filter removes dust from the air, and enters the heat exchange tube to be heated by the radiant heat of the iron trench, and then collects it in the air collecting box. The air collecting box is controlled by the hot air blower to be in a slightly negative pressure state, ensuring that the heated air in the heat exchange tube only enters the air collecting box and does not escape from the dust removal filter port in the reverse direction. The purpose of the heated air in the air collecting box is different from the conventional use of the air as combustion-supporting air to feed the blast furnace. In this structure, the heated air is transported to the silo through a pipeline to bake and preheat the charge entering the blast furnace silo, avoiding moisture in the charge during the rainy season, improving the dryness and temperature of the charge entering the blast furnace, reducing the coke ratio of the blast furnace, and stabilizing the furnace condition.

[0007] Furthermore, the interior of the cover plate is filled with refractory material, the heat exchange tube is made of stainless steel as the base material, and the outer surface is made of metal spraying material.

[0008] Furthermore, a drying preheater is installed in the blast furnace silo, and the drying preheater is connected to the outlet of the hot air blower through a pipeline.

[0009] Furthermore, the drying preheater includes an annular duct and a central duct. The annular duct is fixedly connected to the lower outer wall of the blast furnace bunker, and the annular duct is provided with a first annular air outlet at the joint portion between the annular duct and the side wall of the blast furnace bunker; the central duct is arranged at the axis of the blast furnace bunker, and the side wall and the lower end surface of the central duct are respectively provided with a second air outlet. The annular duct and the central duct dry and heat the charge in the blast furnace bunker from all sides and the center respectively, to ensure that the charge in the blast furnace bunker is dried and to avoid uneven heating.

[0010] Furthermore, the annular air duct is connected to a first pipeline, the central air duct is connected to a second pipeline, and the second pipeline crosses the side wall of the blast furnace silo; the first pipeline and the second pipeline are connected to the output pipeline of the hot air blower through a three-way joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A three-dimensional structural diagram of a molten iron waste heat utilization structure provided by an embodiment of the utility model;

[0012] Figure 2 A top view of a molten iron waste heat utilization structure provided in an embodiment of the utility model;

[0013] Figure 3 for Figure 2 Sectional view of the middle AA plane;

[0014] Figure 4 for Figure 2 Middle BB plane section view;

[0015] The markings in the figure are: 1. Ironmaking ditch cover; 2. Hot air duct; 3. Air collecting box; 4. Hot air blower; 5. Output pipe; 6. Blast furnace silo; 61. Feed inlet; 62. Air outlet; 7. Annular air duct; 71. First branch pipe; 8. Central air duct; 81. Second branch pipe; 9. Dust removal filter; 10. Heat exchange tube. DETAILED DESCRIPTION

[0016] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific implementation methods, but the present invention is not limited thereto.

[0017] like Figures 1 to 3 As shown, the utility model provides a molten iron waste heat utilization structure, including an ironmaking trench cover 1, a wind collecting box 3, a hot air blower 4 and a blast furnace silo 6, etc. The ironmaking trench cover 1 includes a cover plate and a heat exchange tube 10. The cover plate is provided with a mounting groove inside. The mounting groove is a U-shaped rotating integral groove body. The heat exchange tube 10 is coiled in the mounting groove according to the direction of the mounting groove. The heat exchange tube is made of stainless steel as the base material, and the outer surface is made of high-temperature metal spraying material. Preferably, the mounting groove is a double-layer structure.

[0018] A detachable dust filter 9 is installed at the inlet end of the heat exchange tube 10. The dust filter 9 includes a metal end and a filter cartridge. The outer wall of the metal end is provided with a thread, and the inner wall of the end of the heat exchange tube 10 is provided with a thread. The metal end is threadedly connected to the heat exchange tube 10, and the inner end of the metal end is connected to the filter cartridge. The filter cartridge is a cylindrical structure with a filter screen at the bottom. The dust filter 9 is a purchaseable component.

[0019] The outlet end of the heat exchange tube 10 is connected to the hot air duct 2. Since the length of the iron water ditch is relatively long, there are multiple ironmaking ditch covers 1 on one iron water ditch, and each ironmaking ditch cover 1 has an independent heat exchange tube 10. Therefore, there are multiple hot air ducts 2, and these hot air ducts 2 are all collected in the air collecting box 3, and the air collecting box 3 is connected to the inlet of the hot air blower 4. The outlet of the hot air blower 4 is connected to the drying preheater through the output pipe 5, and the drying preheater is fixed in the blast furnace silo 6.

[0020] The blast furnace silo 6 is an inverted truncated cone-shaped cylindrical structure, with a feed port 61 and an air outlet 62 provided on the upper end surface. A feed valve is installed on the pipeline connected to the feed port 61, and the air outlet 62 is connected to the external gas treatment system; a discharge valve is installed on the lower end surface of the blast furnace silo 6.

[0021] like Figure 4As shown, in order to ensure that the heated air has a uniform preheating effect on the entire blast furnace bunker 6, the drying preheater includes an annular duct 7 and a central duct 8. The annular duct 7 is welded and fixed on the outer wall of the lower end of the blast furnace bunker 6, and the side wall of the annular duct 7 and the blast furnace bunker 6 are provided with a first air outlet arranged in an annular direction; the annular duct 7 is connected to the first branch pipe 71. The central duct 8 is arranged on the axis of the blast furnace bunker 6. The central duct 8 is a vertically placed cylindrical structure with upper and lower covers, and the side wall and lower end surface of the cylinder are respectively provided with a second air outlet. The middle part of the central duct 8 is connected with a second branch pipe 81, which crosses the side wall of the blast furnace bunker 6 and is connected to the first branch pipe 71 through a three-way joint, and the other end of the three-way joint is connected to the output pipe 5 of the hot air blower 4. Preferably, the apertures of the first and second air outlets are smaller than the size of the charge, and both the first and second air outlets are vertical or bottom holes, which are not easily blocked by the charge, thus ensuring smooth ventilation. When the charge is small, a fine mesh screen ( Figure 4 The lower middle part is a schematic diagram of the second air outlet with a dense mesh screen), which ensures ventilation while preventing the air outlet from being blocked.

[0022] Working process: turn on the hot air blower 4, draw in external cold air from the inlet of the heat exchange tube 10, and the dust filter 9 filters and removes dust from the external cold air. The dust-removed cold air flows in the heat exchange tube 10 to undergo heat exchange and absorb the radiant heat in the ironmaking ditch. The heated hot air is collected in the air collecting box 3 and transported to the drying preheater through the hot air blower 4. A part of the hot air is blown into the bottom of the blast furnace silo 6 from the bottom annular air duct 7, and gradually rises in the gaps between the charges to dry and heat the charge in the entire blast furnace silo 6. Finally, the gas is discharged to the gas treatment system from the air outlet 62; another part of the hot air is blown into the center of the blast furnace silo 6 from the central air duct 8 to dry and heat the charge at the center to prevent the charge from getting wet and agglomerated in the center.

[0023] Finally, it should be noted that the above-listed examples are only preferred embodiments of the present invention. Of course, those skilled in the art can make changes and modifications to the present invention. If these modifications and modifications fall within the scope of the claims of the present invention and their equivalent technologies, they should be considered to be within the scope of protection of the present invention.

Claims

1. A molten iron waste heat utilization structure, comprising an ironmaking trench cover, a wind collecting box and a blast furnace silo; characterized in that: The ironmaking trench cover includes a cover plate and a heat exchange tube. An installation groove is opened inside the cover plate, and the heat exchange tube is coiled in the installation groove. A dust removal filter is installed at one end of the heat exchange tube, and the other end of the heat exchange tube is connected to a hot air duct. The hot air duct is collected in an air collecting box, and the air collecting box is connected to the inlet of the hot air blower. The outlet of the hot air blower is connected to the blast furnace silo through a pipeline and a drying preheater.

2. The molten iron waste heat utilization structure according to claim 1, characterized in that: The inside of the cover plate is filled with refractory material, the heat exchange tube is made of stainless steel as the base material, and the outer surface is made of metal spraying material.

3. The molten iron waste heat utilization structure according to claim 1, characterized in that: A drying preheater is installed in the blast furnace silo, and the drying preheater is connected to the outlet of the hot air blower through a pipeline.

4. The molten iron waste heat utilization structure according to claim 3, characterized in that: The drying preheater includes an annular air duct and a central air duct. The annular air duct is fixedly connected to the lower outer wall of the blast furnace silo, and a first annular air outlet is provided at the connecting and fitting part between the annular air duct and the side wall of the blast furnace silo; the central air duct is arranged at the axis of the blast furnace silo, and a second air outlet is provided on the side wall and the lower end face of the central air duct respectively.

5. The molten iron waste heat utilization structure according to claim 4, characterized in that: The annular air duct is connected with a first pipeline, the central air duct is connected with a second pipeline, and the second pipeline crosses the side wall of the blast furnace silo; the first pipeline and the second pipeline are connected with the output pipeline of the hot air blower through a three-way joint.

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