Energy-saving waste heat recovery device for aluminum alloy smelting

Abstract

This utility model discloses an energy-saving waste heat recovery device for aluminum alloy smelting, belonging to the field of aluminum alloy smelting technology. The energy-saving waste heat recovery device for aluminum alloy smelting includes a smelting furnace, with a burner installed at the top. The air inlet of the burner is connected to a blower. A flue for discharging flue gas is installed on one side of the smelting furnace, and a feed pipe for preheating aluminum alloy raw materials is fitted outside the flue. This utility model utilizes the heat of the high-temperature flue gas in multiple stages. First, the heat from the flue wall is used to preheat the aluminum alloy raw materials in the feed pipe. Then, the flue gas enters a heat exchanger, using the remaining heat to heat the combustion air. Finally, the heat exchanger tubes are sprayed and cleaned. This multi-stage utilization method maximizes the recovery of waste heat from the flue gas and significantly reduces the fuel consumption of the smelting furnace.

Description

Technical Field

[0001] This utility model relates to the field of aluminum alloy smelting technology, and more specifically, to an energy-saving waste heat recovery device for aluminum alloy smelting. Background Technology

[0002] Existing waste heat recovery methods mainly fall into two categories: one is using waste heat boilers to generate steam, but this system is complex, has a long investment payback period, and the steam needs to be converted and reused twice in the smelting workshop, resulting in significant efficiency losses; the other is using traditional heat exchangers to preheat combustion air, but the flue gas from aluminum alloy smelting has a complex composition, containing corrosive substances such as chloride salts, fluoride salts, and sulfur oxides, which easily condense on the heat exchanger walls to form acidic liquids, causing severe low-temperature acid dew point corrosion, leading to shortened equipment lifespan, high maintenance costs, and affecting its long-term stable operation. Furthermore, existing technologies mostly focus on recovering the sensible heat of the flue gas, neglecting the preheating of materials before they enter the furnace. Directly adding cold materials to the smelting furnace significantly increases smelting time and energy consumption. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and to provide an energy-saving waste heat recovery device for aluminum alloy smelting, thereby solving the above-mentioned deficiencies.

[0004] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0005] This utility model discloses an energy-saving waste heat recovery device for aluminum alloy smelting, comprising a smelting furnace, a burner at the upper end of the smelting furnace, an air inlet of the burner connected to a blower, a flue for discharging flue gas on one side of the smelting furnace, a feed pipe for preheating aluminum alloy raw materials sleeved outside the flue, a spiral guide plate inside the feed pipe, and the lower outlet of the feed pipe corresponding to the feed hole on the smelting furnace; a heat exchanger is connected to the upper outlet of the flue, the heat exchanger includes a shell and heat exchange tubes disposed within the shell, the outlet of the heat exchange tubes is connected to the air inlet of the blower, and a flue outlet is provided at the top of the shell.

[0006] Preferably, the flue includes a lower inlet, a straight pipe, and an upper outlet connected sequentially from bottom to top. Both the lower inlet and the upper outlet are conical structures. The end of the lower inlet with the larger diameter is connected to the smelting furnace, and the end of the upper outlet with the larger diameter is connected to the shell of the heat exchanger.

[0007] Preferably, the upper outlet is provided with a uniform distribution plate at the connection between the upper outlet and the shell, and the uniform distribution plate has multiple dispersing holes.

[0008] Preferably, the top of the housing is further provided with a spray system, which includes a spray pipe and an inlet pipe for providing an alkaline aqueous solution to the spray pipe.

[0009] Preferably, the upper outlet is provided with a sealing block that can move up and down, the upper end of the sealing block is connected to a threaded rod, the threaded rod extends to the outside of the shell and engages with the shell, and the side wall of the upper outlet is also provided with a liquid outlet.

[0010] Preferably, the upper and lower surfaces of the sealing block are both conical structures, and their shapes are adapted to the conical inner wall of the upper outlet.

[0011] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0012] This utility model discloses an energy-saving waste heat recovery device for aluminum alloy smelting. Through ingenious structural design, it utilizes the heat of high-temperature flue gas in multiple stages. First, the heat from the flue wall is used to preheat the aluminum alloy raw material in the feed pipe. Then, the flue gas enters the heat exchanger, where the remaining heat is used to heat the combustion air. Finally, the heat exchanger tubes are sprayed and cleaned. This multi-stage utilization method maximizes the recovery of waste heat from the flue gas and significantly reduces the fuel consumption of the smelting furnace. The spiral feed pipe, fitted outside the flue, greatly increases the heating area and residence time of the aluminum alloy raw material, ensuring it is fully heated. The preheating process is thorough and uniform. Preheated raw materials entering the melting furnace significantly shorten melting time and reduce heat consumption, thus directly lowering energy costs. The structure of the feed pipe sleeved outside the flue acts as an insulation layer for the high-temperature flue, effectively reducing heat loss to the surrounding environment and further improving system thermal efficiency. The sealing block and liquid outlet design facilitates waste liquid collection and discharge, making maintenance easy. The uniform distribution plate at the upper outlet of the flue ensures that flue gas enters the heat exchanger shell evenly and contacts the heat exchange tubes, preventing short-circuiting and ensuring uniform and efficient heat exchange. Attached Figure Description

[0013] Figure 1 This is an overall structural diagram of the energy-saving waste heat recovery device for aluminum alloy smelting according to this utility model;

[0014] Figure 2 This is a structural diagram showing the connection between the flue, feed pipe, and heat exchanger of this utility model.

[0015] Figure 3 This is a structural diagram of the uniformly distributed plate of this utility model;

[0016] Figure 4 This is a structural diagram of the sealing block of this utility model.

[0017] In the diagram: 1. Smelting furnace; 11. Burner; 12. Blower; 2. Flue; 21. Lower inlet; 22. Straight pipe; 23. Upper outlet; 231. Distribution plate; 2311. Dispersion hole; 232. Sealing block; 233. Threaded rod; 234. Liquid outlet; 3. Feed pipe; 31. Spiral guide vane; 4. Heat exchanger; 41. Heat exchanger tube side; 42. Shell; 421. Flue outlet; 422. Spray pipe; 423. Water inlet pipe; 424. Threaded sleeve. Detailed Implementation

[0018] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0019] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings.

[0020] Combination Figures 1-4 The present invention relates to an energy-saving waste heat recovery device for aluminum alloy smelting, comprising a smelting furnace 1, a burner 11 at the upper end of the smelting furnace 1, a blower 12 connected to the air inlet of the burner 11, and a flue 2 on one side of the smelting furnace 1, through which the flue gas generated in the reaction inside the smelting furnace 1 is discharged.

[0021] The high-temperature flue gas inside flue 2 heats the sidewalls of flue 2. A feed pipe 3 is installed outside flue 2. The high temperature of the sidewalls of flue 2 heats the aluminum alloy inside the feed pipe 3. At the same time, the feed pipe 3 is installed outside flue 2 to further reduce heat loss. A spiral guide plate 31 is installed inside the feed pipe 3. A feed port is provided on one side of the upper end of the feed pipe 3. Aluminum alloy raw material is put into the feed port. Under its own weight, the material slides down along the spiral guide plate 31, increasing the heating time of the aluminum alloy raw material. The end of the spiral guide plate 31 corresponds to the feed hole opened on the melting furnace 1, which sends the material into the melting furnace 1. The material entering the melting furnace 1 first comes into contact with the rising flue gas and is further heated.

[0022] Specifically, the flue 2 includes a lower inlet 21, a straight pipe 22, and an upper outlet 23 connected sequentially from bottom to top. The lower inlet 21 has a conical structure, with the larger diameter end connected to the smelting furnace 1, which can quickly guide most of the flue gas into the flue 2. The straight pipe 22 serves as a transition. In addition, the upper outlet 23 also has a conical structure, and the larger diameter end of the upper outlet 23 is away from the straight pipe 22 and is connected to a heat exchanger 4. The flue gas entering the upper outlet 23 is diffused. A uniform distribution plate 231 is provided at the connection between the upper outlet 23 and the heat exchanger 4. The uniform distribution plate 231 has dispersion holes 2311, and the rising flue gas passes through the dispersion holes 2311 and is evenly distributed.

[0023] More specifically, the heat exchanger 4 includes a heat exchange tube side 41 and a shell 42, wherein the shell 42 is connected to the upper outlet 23, both ends of the heat exchange tube side 41 extend to the outside of the shell 42, and one end of the heat exchange tube side 41 is connected to the air inlet of the blower 12. External air enters the heat exchange tube side 41 from one end of the heat exchange tube side 41. After heat exchange, the cold air becomes hot air and enters the blower 12, and is sent to the burner 11 by the blower 12 to reduce energy loss.

[0024] It should be noted that the upper end of the shell 42 is provided with a flue gas outlet 421, which is connected to the flue gas treatment device to treat the flue gas for harmless treatment before discharge. The top of the shell 42 is also equipped with a spray system, including a spray pipe 422 and a water inlet pipe 423. The water inlet pipe 423 provides an alkaline aqueous solution to the spray pipe 422 for spraying the heat exchange tubes 41, preventing scale buildup on the surface of the heat exchange tubes 41 from affecting the heat exchange efficiency. The waste liquid after spraying is collected through the lower inlet 21. Therefore, a sealing block 232 is installed inside the upper outlet 23. The upper and lower surfaces of the sealing block 232 are both conical structures. A threaded rod 233 is fixedly connected to the upper end. The threaded rod 233 extends to the upper end of the housing 42 and engages with the threaded sleeve 424 provided at the upper end of the housing 42. By turning the threaded rod 233, the up and down position of the sealing block 232 can be controlled. When the sealing block 232 moves down to fit the upper outlet 23, the lower end of the lower inlet 21 is blocked, and the waste liquid is collected in the upper outlet 23. A liquid outlet 234 is provided on one side of the upper outlet 23 for discharging the waste liquid. When the sealing block 232 does not fit with the upper outlet 23, the upper outlet 23 is connected to the housing 42, and the flue gas can pass through. At this time, the liquid outlet 234 is sealed with a sealing plug.

[0025] Working process: The burner 11 in the smelting furnace 1 operates to melt the aluminum alloy inside the furnace. The generated high-temperature flue gas enters from the lower inlet 21 of the flue 2. The high-temperature flue gas flows through the flue 2, heating its side walls. The aluminum alloy raw material in the feed pipe 3 outside the flue 2 is fully preheated by the heat of the flue 2 wall as it slowly slides down along the spiral guide plate 31. The preheated flue gas diffuses through the conical structure of the upper outlet 23 and is evenly distributed through the dispersion holes 2311 of the distribution plate 231 before entering the shell 42 of the heat exchanger 4. The blower 12 blows ambient air into the heat exchange tube side 41 of the heat exchanger 4. As the air flows through the tube side, it exchanges heat with the flue gas in the shell side and is heated into hot air before being sent to the burner 11 for further processing. To aid combustion and reduce fuel consumption for heating the combustion air, the low-temperature flue gas after heat exchange is discharged from the flue gas outlet 421 at the top of the shell 42 and enters the subsequent flue gas treatment device for purification before being discharged. When cleaning is required, the threaded rod 233 is screwed to drive the sealing block 232 to move down and fit against the inner wall of the upper outlet 23, blocking the flue gas passage. The spray system is then turned on, and alkaline water is sprayed onto the surface of the heat exchange tube 41 through the spray pipe 422 for cleaning. The waste liquid is collected in the conical upper outlet 23 and discharged through the liquid outlet 234. After cleaning, the spray system is turned off, the sealing block 232 is lifted back to its original position to clear the flue gas passage, and the liquid outlet 234 is sealed with a sealing plug, and the device returns to normal operation.

[0026] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0027] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention.

Claims

1. An energy saving waste heat recovery device for aluminum alloy smelting, comprising a smelting furnace (1), characterized in that, The upper end of the smelting furnace (1) is provided with a burner (11), and the air inlet of the burner (11) is connected to a blower (12). A flue (2) for discharging flue gas is provided on one side of the smelting furnace (1). A feed pipe (3) for preheating aluminum alloy raw materials is sleeved on the outside of the flue (2). A spiral guide plate (31) is provided inside the feed pipe (3), and the lower end outlet of the feed pipe (3) corresponds to the feed hole on the smelting furnace (1). A heat exchanger (4) is connected to the upper end outlet of the flue (2). The heat exchanger (4) includes a shell (42) and a heat exchange tube (41) set in the shell (42). The outlet of the heat exchange tube (41) is connected to the air inlet of the blower (12). A flue outlet (421) is provided on the top of the shell (42).

2. The energy-saving waste heat recovery device for aluminum alloy smelting according to claim 1, characterized in that, The flue (2) includes a lower inlet (21), a straight pipe (22) and an upper outlet (23) connected sequentially from bottom to top. Both the lower inlet (21) and the upper outlet (23) are conical structures. The end with the larger diameter of the lower inlet (21) is connected to the smelting furnace (1), and the end with the larger diameter of the upper outlet (23) is connected to the shell (42) of the heat exchanger (4).

3. The energy-saving waste heat recovery device for aluminum alloy smelting according to claim 2, characterized in that, A uniform distribution plate (231) is provided at the connection between the upper outlet (23) and the shell (42), and a plurality of dispersion holes (2311) are provided on the uniform distribution plate (231).

4. The energy-saving waste heat recovery device for aluminum alloy smelting according to claim 3, characterized in that, The top of the housing (42) is also provided with a spray system, which includes a spray pipe (422) and an inlet pipe (423) for providing an alkaline aqueous solution to the spray pipe (422).

5. The energy-saving waste heat recovery device for aluminum alloy smelting according to claim 4, characterized in that, The upper outlet (23) is provided with a sealing block (232) that can move up and down. The upper end of the sealing block (232) is connected to a threaded rod (233). The threaded rod (233) extends to the outside of the housing (42) and engages with the housing (42). The side wall of the upper outlet (23) is also provided with a liquid outlet (234).

6. The energy-saving waste heat recovery device for aluminum alloy smelting according to claim 5, characterized in that, The upper and lower surfaces of the sealing block (232) are both conical structures, and their shape is adapted to the conical inner wall of the upper outlet (23).

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