Online molten aluminum degassing equipment for gradient utilization of waste gas

Abstract

The molten aluminum online degassing equipment for waste gas gradient utilization comprises a degassing box, the degassing box is provided with a plurality of degassing grooves, the outermost degassing groove is communicated with the outside for molten aluminum which is not degassed to flow into the grooves, and the equipment is provided with a gas supply mechanism for providing inert gas for all the degassing grooves so as to remove hydrogen in the molten aluminum in all the degassing grooves. A liquid outlet groove is formed in the groove wall of the most front degassing groove and communicated with the outside so that degassed molten aluminum can flow out of the grooves, the degassing box is further provided with a waste gas utilization groove, the most rear degassing groove is particularly communicated with the outside through the waste gas utilization groove, waste gas of the most front degassing groove is pumped into the waste gas utilization groove through a first gas pump, and hydrogen in the molten aluminum in the waste gas utilization groove is removed. The gas pumping flow of the first gas pump is smaller than the flow of inert gas input to the most front degassing tank by the gas supply mechanism, and the second gas pump pumps waste gas of the degassing tank adjacent to the most front degassing tank to the liquid outlet tank to form a gas curtain. According to the invention, gradient utilization of low-hydrogen-content waste gas and secondary low-hydrogen-content waste gas is realized.

Description

Technical Field

[0001] This invention relates to the field of online degassing technology, and more specifically to online degassing equipment for molten aluminum. Background Technology

[0002] The online degassing equipment for molten aluminum includes a degassing box containing multiple degassing tanks arranged side-by-side. The left wall of the rearmost degassing tank has an inlet tank, and the left wall of the frontmost degassing tank has an outlet tank. Undegassed molten aluminum from the furnace enters the rearmost degassing tank through the inlet tank and flows sequentially from back to front within the degassing box, passing through each degassing tank in turn. A cover plate is installed above the degassing box, covering all the degassing tanks. Multiple degassing units are mounted on the cover plate, each corresponding to one of the degassing tanks. The online degassing equipment for molten aluminum is equipped with a gas supply mechanism to provide inert gases such as nitrogen to each degassing unit. The degassing unit introduces the inert gas into the bottom of the molten aluminum, forming tiny bubbles. Due to the extremely low hydrogen partial pressure of the inert gas bubbles, hydrogen atoms in the molten aluminum combine on the bubble surface to form hydrogen molecules (i.e., hydrogen gas). The hydrogen gas rises with the bubbles and escapes from the molten aluminum, thus achieving hydrogen removal from the molten aluminum. After undergoing multi-stage degassing, the molten aluminum finally flows out of the outlet tank and is transported to subsequent casting equipment.

[0003] During the degassing process, hydrogen and nitrogen rise to the top of the degassing tank, forming hydrogen-containing waste gas. Normally, this waste gas is directly discharged to the outside. However, because the aluminum liquid undergoes gradual dehydrogenation from back to front, the hydrogen content of the aluminum liquid flowing into the foremost degassing tank has significantly decreased. Therefore, the hydrogen concentration in the waste gas from this tank is low, and the main component is nitrogen. Directly discharging this low-hydrogen-content waste gas would result in a waste of nitrogen. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an online degassing device for molten aluminum with waste gas utilization in stages.

[0005] To solve the above-mentioned technical problems, the present invention provides an online degassing device for aluminum liquid with waste gas utilization in stages. The device includes a degassing box with multiple degassing tanks arranged in parallel. The rearmost degassing tank is connected to the outside environment, allowing undegassed aluminum liquid to flow into it. The device has a gas supply mechanism that provides inert gas to each degassing tank to remove hydrogen from the aluminum liquid within each tank. The frontmost degassing tank has an outlet channel on its wall, connecting to the outside environment for the degassed aluminum liquid to flow out. The degassing box also includes a waste gas utilization tank, with the rearmost degassing tank specifically connected to the outside environment via this tank. The device includes a first air pump and a second air pump. The first air pump draws the waste gas from the frontmost degassing tank to the waste gas utilization tank to remove hydrogen from the aluminum liquid within it. The pumping flow rate of the first air pump is less than the flow rate of inert gas supplied by the gas supply mechanism to the frontmost degassing tank. The second air pump draws the waste gas from the degassing tank adjacent to the frontmost degassing tank to the outlet channel, forming an air curtain.

[0006] Furthermore, there are three degassing tanks, arranged from back to front. The waste gas utilization tank is located behind the first degassing tank. The left wall of the waste gas utilization tank has a liquid inlet tank, which connects to the outside world. The bottom of the partition between the waste gas utilization tank and the first degassing tank has a first through hole connecting the two tanks. The top of the partition between the first and second degassing tanks has a second through hole connecting the two tanks. The bottom of the partition between the second and third degassing tanks has a third through hole connecting the two tanks.

[0007] Furthermore, the liquid outlet tank is specifically located on the left wall of the third degassing tank, supplying the aluminum liquid in the tank to flow to the left. A cover plate is provided on the degassing tank to cover the waste gas utilization tank and the three degassing tanks. The cover plate extends downwards with a protrusion that sinks into the top of the liquid outlet tank. The cover plate has an air supply channel. The liquid inlet end of the air supply channel is connected to the second air pump, and the liquid outlet end extends to the left wall of the protrusion and is a strip in the front-to-back direction.

[0008] Furthermore, a liquid outlet guide trough is provided to connect to the liquid outlet tank, guiding the degassed aluminum liquid to the casting equipment; a hollow insulation layer is provided on the outer periphery of the liquid outlet guide trough, and an air outlet hole is opened on the cover plate. An air guide pipe is provided at the air outlet hole to connect to the hollow insulation layer, guiding the waste gas from the first degassed tank to the hollow insulation layer, thereby insulating the liquid outlet guide trough.

[0009] Furthermore, a drive mechanism is provided to rotate the degassing box to an inclined state, thereby emptying the waste gas utilization tank and the residual aluminum liquid in each degassing tank.

[0010] Furthermore, the left side of the box has a flow channel running in the front-to-back direction. The rear end of the flow channel is the liquid inlet for undegassed aluminum liquid to flow into the flow channel, and the front end of the flow channel is the liquid outlet for degassed aluminum liquid to be discharged out of the flow channel. The liquid inlet and liquid outlet channels are respectively connected to the front and rear sections of the flow channel to the left. A block is installed on the flow channel, located between the liquid inlet and liquid outlet channels. The block can be moved to the liquid inlet at the rear end of the flow channel. The drive mechanism specifically drives the degassing box to rotate to the left to pour out the residual aluminum liquid in the waste gas utilization channel and each degassing channel. When the block is moved to the liquid inlet at the rear end of the flow channel and the drive mechanism drives the degassing box to rotate to the left, the residual aluminum liquid in the waste gas utilization channel and the third degassing channel is poured into the flow channel through the liquid inlet and liquid outlet channels, respectively.

[0011] Furthermore, the left wall of the first and second degassing tanks has two parallel connecting channels facing the middle of the left connecting channel. The cover plate extends downwards with two plugs blocking the two connecting channels respectively. There are two plugs, one in front and one in back. The back plug is located between the liquid inlet tank and the rear connecting channel, and the front plug is located between the liquid outlet tank and the front connecting channel. A lifting mechanism is provided to lift the cover plate so that the two plugs no longer block the two connecting channels. Both plugs are moved to the liquid inlet at the rear end of the channel, and the drive mechanism drives the degassing box to rotate to an inclined state after the cover plate is lifted. The residual aluminum liquid in the first and second degassing tanks is poured from the two connecting channels into the channel respectively.

[0012] Furthermore, the cover plate is equipped with a first, second, and third degassing unit. An air supply mechanism is connected to these three degassing units to provide inert gas. The three degassing units respectively input the inert gas into the bottom of the three degassing tanks to remove hydrogen from the molten aluminum in the three degassing tanks. The cover plate is also equipped with a fourth degassing unit. A first air pump draws the exhaust gas from the third degassing tank to the fourth degassing unit. The fourth degassing unit inputs the exhaust gas into the bottom of the exhaust gas utilization tank to remove hydrogen from the molten aluminum in the exhaust gas utilization tank.

[0013] The exhaust gas discharged from the foremost degassing tank has the lowest hydrogen concentration, classifying it as low-hydrogen exhaust gas. The exhaust gas from adjacent degassing tanks has a slightly higher hydrogen concentration, but remains at a low level overall, classifying it as slightly lower-hydrogen exhaust gas. The molten aluminum in the exhaust gas utilization tank has not yet undergone degassing treatment and has the highest hydrogen content. This invention achieves the tiered utilization of low-hydrogen and slightly lower-hydrogen exhaust gases. Specifically:

[0014] This invention uses a first air pump to pump the low-hydrogen-content waste gas from the foremost degassing tank to the waste gas utilization tank, where the high-hydrogen aluminum liquid is degassed, thus achieving the effective utilization of high-purity inert waste gas.

[0015] The first air pump's pumping flow rate is less than the inert gas flow rate supplied by the gas supply mechanism to the foremost degassing tank, ensuring that the degassing tank maintains a slightly positive pressure during normal operation and preventing the intrusion of outside air. However, due to factors such as temperature fluctuations and changes in gas flow rate, the foremost degassing tank may still experience transient negative pressure. In this case, outside air may be drawn back into the foremost degassing tank from the liquid outlet tank, and the oxygen in the air can easily lead to the oxidation of the molten aluminum. To address this, the present invention includes a second air pump, which draws the slightly lower hydrogen-containing waste gas generated by the degassing tank adjacent to the foremost degassing tank to the liquid outlet tank area to form a stable gas curtain, which constitutes a dynamic gas seal barrier. When the foremost degassing tank experiences transient negative pressure, the gas drawn into it through the liquid outlet tank mainly comes from the gas curtain recirculation, rather than external ambient air. Since this recirculated gas mainly consists of a large amount of nitrogen and a small amount of hydrogen, its chemical properties are stable and it is not easy to react with the molten aluminum, significantly reducing the risk of molten aluminum oxidation. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an online degassing device for molten aluminum.

[0017] Figure 2 yes Figure 1 A magnified view of a portion of the image, showing a larger area. Figure 1 Part A.

[0018] Figure 3 It is a cross-sectional view of the degassing box, the four degassing units, and the first extraction pipe.

[0019] Figure 4 This is a cross-sectional view of the protrusion and the second air outlet.

[0020] Figure 5 This is a schematic diagram of the lifting mechanism after the cover plate has been lifted.

[0021] Figure 6 This is a schematic diagram of the drive mechanism driving the degassing box to rotate and pour liquid.

[0022] Figure 7 This is a schematic diagram of the online degassing equipment for molten aluminum according to the second embodiment. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments.

[0024] First embodiment:

[0025] Online degassing equipment for molten aluminum (see below) Figure 5 The system includes a degassing chamber 1, which contains three partitions 11, 12, and 13. The first partition 11 is located at the rear, the second partition 12 is in the middle, and the third partition 13 is at the front. These three partitions divide the interior space of the degassing chamber 1 into four compartments. These four compartments are arranged side-by-side, and from back to front, they are: exhaust gas utilization compartment 20, first degassing compartment 21, second degassing compartment 22, and third degassing compartment 23. The bottom of the first partition 11 has a first through hole 111 connecting the bottom of the exhaust gas utilization compartment 20 and the bottom of the first degassing compartment 21. The top of the second partition 12 has a second through hole 121 connecting the tops of the first and second degassing compartments 21 and 22. The bottom of the third partition 13 has a third through hole 131 connecting the bottoms of the second and third degassing compartments 22 and 23. The front of the degassing box 1 has a flow channel 15 running in a front-to-back direction. The left walls of the exhaust gas utilization channel 20 and the first, second, and third degassing channels 21, 22, and 23 have first, second, third, and fourth connecting channels 31, 32, 33, and 34, respectively. The first and fourth connecting channels 31 and 34 connect to the front section 151 and rear section 152 of the flow channel 15, respectively. The second and third connecting channels 32 and 33 connect to the middle section 153 of the flow channel 15. The third degassing channel 23 connects to the outside via the fourth connecting channel 34. The exhaust gas utilization channel 20 connects to the outside via the first connecting channel 31. The first degassing channel 21 connects to the outside via the exhaust gas utilization channel 20 and the first connecting channel 31. The flow channel 15 is equipped with two blocking blocks 41 and 42, one at the front and one at the rear, respectively. Figure 1 and Figure 5The front blocking block 41 blocks between the third and fourth connecting slots 33 and 34, and the rear blocking block 42 blocks between the first and second connecting slots 31 and 32. A cover plate 5 is provided above the degassing box 1 to cover the waste gas utilization slot 20 and three degassing slots 21, 22, and 23. Three degassing units 61, 62, and 63 are installed on the cover plate 5, arranged in a front-to-back pattern. The three degassing units 61, 62, and 63 are all existing technologies, and are ordered from back to front as the first, second, and third degassing units 61, 62, and 63, corresponding to the three degassing slots 21, 22, and 23 respectively. Taking the third degassing unit 63 as an example... Figure 1 and Figure 3 The third degassing unit 63 has a hollow rotor 601 extending downwards into the third degassing groove 23, and a drive motor 602 for rotating the hollow rotor 601. An air inlet pipe 603 is connected to the top of the hollow rotor 601. The other two degassing units 61 and 62 have the same structure as the third degassing unit 63 and will not be described in detail. See Figure 1 and Figure 5 The cover plate 5 extends downwards with two plugs 51 and 52, which respectively block the second and third connecting channels 32 and 33. The first connecting channel 31 serves as the liquid inlet channel, and the fourth connecting channel 34 serves as the liquid outlet channel.

[0026] See Figure 1 , Figure 3 and Figure 5The online degassing equipment for molten aluminum is equipped with a rearward inlet guide channel 71 and a forward outlet guide channel 72. An inlet 155 is located at the rear end of the flow channel 15, connecting to the inlet guide channel 71, which in turn connects to a furnace (not shown in the figure). An outlet 156 is located at the front end of the flow channel 15, connecting to the outlet guide channel 72, which in turn connects to a casting equipment (not shown in the figure). Undegassed molten aluminum from the furnace enters the inlet guide channel 71 and then flows forward from the rear inlet 155 into the flow channel 15. It flows forward along the flow channel 15 to the first connecting channel 31, where it is blocked by a rear block 42 and cannot continue flowing forward. Instead, it flows from the first connecting channel 31 into the waste gas utilization channel 20. The molten aluminum flowing into the waste gas utilization channel 20 passes through the first through hole 111 at the bottom of the waste gas utilization channel 20 and flows forward into the first degassing channel 21. As molten aluminum continues to flow into the first degassing tank 21, the level of molten aluminum in the first degassing tank 21 gradually rises. When the level of molten aluminum in the first degassing tank 21 rises above the bottom wall of the second flow hole 121, the molten aluminum flows forward from the top of the first degassing tank 21 through the second flow hole 121 into the second degassing tank 22. The molten aluminum flowing into the second degassing tank 22 then flows forward from the bottom of the second degassing tank 22 through the third through hole 131 into the third degassing tank 23. The online degassing equipment for molten aluminum is equipped with a nitrogen gas source (not shown in the figure; other embodiments may use other inert gas sources, such as argon gas sources) and a nitrogen gas pump (not shown in the figure). Both are existing technologies and together form a gas supply mechanism. The inlet pipes 603 of the three degassing units 61, 62, and 63 are all connected to the nitrogen gas pump. After the molten aluminum flows into the degassing tank 1, the workers start the nitrogen pump to supply nitrogen to the three degassing units 61, 62, and 63. The three degassing units 61, 62, and 63 operate in the same way; taking the third degassing unit 63 as an example, nitrogen enters the hollow rotor 601 through the inlet pipe 603, flows downwards along the rotor to its bottom, and then enters the bottom of the third degassing tank 23, forming nitrogen bubbles. Due to the extremely low hydrogen partial pressure of the nitrogen bubbles, hydrogen atoms in the molten aluminum combine on the surface of the nitrogen bubbles to form hydrogen molecules (i.e., hydrogen gas). The hydrogen gas floats to the surface of the molten aluminum along with the nitrogen bubbles and escapes outside the molten aluminum. Degassing unit 63 removes hydrogen from the molten aluminum in this way. The operator can start the air pump simultaneously with the drive motor 602 of the degassing unit 63, driving the hollow rotor 601 to rotate around its vertical axis. The lower end of the hollow rotor 601 breaks down larger nitrogen bubbles in the third degassing tank 23 into numerous smaller nitrogen bubbles, enhancing the degassing effect. The other two degassing units 61 and 62 operate in the same manner as the third degassing unit 63. As molten aluminum continues to flow into the third degassing tank 23, the level of the molten aluminum in the tank gradually rises.When the aluminum liquid level in the third degassing tank 23 rises above the bottom wall of the fourth connecting tank 34, the degassed aluminum liquid in the third degassing tank 23 flows to the left from the fourth connecting tank 34 to the front section of the flow channel 15. Due to the obstruction of the front block 41, it cannot flow backward but flows forward from the liquid outlet 156 at the front end of the flow channel 15 into the liquid outlet guide channel 72, and then flows along the liquid outlet guide channel 72 to the casting equipment under the guidance of the liquid outlet guide channel 72.

[0027] See Figure 1 and Figure 3 After hydrogen and nitrogen rise to the surface, they form hydrogen-containing waste gas in the degassing tank 1. Since the molten aluminum flows from back to front, passing through three degassing tanks 21, 22, and 23 sequentially, it is gradually dehydrogenated by the first, second, and third degassing units 61, 62, and 63. The hydrogen content of the molten aluminum flowing into the second degassing tank 22 has decreased, and the hydrogen content of the molten aluminum flowing into the third degassing tank 23 has decreased significantly. Therefore, the waste gas in the third degassing tank 23 has the lowest hydrogen concentration and is classified as low-hydrogen waste gas, with nitrogen as its main component. A first booster pump 81 and a fourth degassing unit 64 are installed on the cover plate 5. The first booster pump 81 has a first extraction pipe 811 connected to its inlet and a first outlet pipe 812 connected to its outlet. The first extraction pipe 811 connects to the top of the third degassing tank 23. The fourth degassing unit 64 corresponds to the waste gas utilization tank 20. It has the same structure and operating method as the first, second, and third degassing units 61, 62, and 63. All three remove hydrogen from the molten aluminum by inputting nitrogen into the hollow rotor 601 and driving the rotor 601 with the drive motor 602 to disperse nitrogen bubbles. The difference lies in that the inlet pipe 603 of the fourth degassing unit 64 is not connected to the nitrogen pump but to the first outlet pipe 812. The operator starts the drive motor 602 of the fourth degassing unit 64 after the nitrogen pump has been running for a period of time (1-3 minutes in this embodiment), simultaneously starting the first booster pump 81. The first booster pump 81 draws the low-hydrogen-content waste gas from the top of the third degassing tank 23 into the inlet pipe 603 of the fourth degassing unit 64, thus providing nitrogen to the fourth degassing unit 64. Because this waste gas has a high nitrogen content and a low hydrogen content, it still possesses good inert atmosphere characteristics. When the low-hydrogen-content waste gas is fed into the bottom of the waste gas utilization tank 20 via the hollow rotor 601 of the fourth degassing unit 64, a large number of tiny bubbles can be formed in the high-hydrogen aluminum liquid in the waste gas utilization tank 20. The low hydrogen partial pressure environment is used to remove hydrogen from the aluminum liquid. In this way, the fourth degassing unit 64 achieves effective utilization of the low-hydrogen-content waste gas from the third degassing tank 23.

[0028] See Figure 1The pumping flow rate of the first booster pump 81 (12-16 L / min in this embodiment) is less than the nitrogen flow rate (20 L / min in this embodiment) input to the third degassing tank 23 by the gas supply mechanism, ensuring that the third degassing tank 23 maintains a slightly positive pressure during normal operation to prevent the intrusion of outside air. However, due to factors such as temperature fluctuations and changes in gas flow rate, the third degassing tank 23 may still experience transient negative pressure. In this case, outside air may be drawn back into the third degassing tank 23 from the fourth connecting channel 34, and the oxygen in the air can easily cause the aluminum liquid to oxidize. To address this, a second booster pump 82 is installed on the cover plate 5. The second booster pump 82 has a second suction pipe 821 connected to its inlet end and a second outlet pipe 822 connected to its outlet end. The second suction pipe 821 connects to the second degassing tank 22 (see...). Figure 3 (Top) See Figure 1 , Figure 2 and Figure 4 The cover plate 5 extends downwards with a protrusion 56 that sinks into the top of the fourth connecting groove 34. The cover plate 5 has a gas supply channel 57. The inlet end 571 of the gas supply channel 57 extends upwards to the top wall of the cover plate 5, and the outlet end 572 extends to the left to the left wall of the protrusion 56, forming a strip in the front-to-back direction. The second outlet pipe 822 connects to the inlet end 571 of the gas supply channel 57. While starting the nitrogen pump, the operator simultaneously starts the second booster pump 82 to fill the second degassing tank 22 (see...). Figure 3 The exhaust gas at the top is drawn into the gas delivery channel 57, and then swept to the left from the outlet 572 of the gas delivery channel 57, thus forming a protective air curtain at the fourth connecting groove 34. This air curtain constitutes a dynamic air seal barrier. See Figure 1 , Figure 3 and Figure 4 After the first booster pump 81 starts, the molten aluminum flowing into the second degassing tank 22 has already been degassed twice by the first and fourth degassing units 61 and 64. The hydrogen content in this molten aluminum has been significantly reduced. Therefore, although the hydrogen concentration of the exhaust gas in the second degassing tank 22 is higher than that in the third degassing tank 23, it is still at a relatively low level, belonging to the category of low-hydrogen-content exhaust gas, mainly containing nitrogen and a small amount of hydrogen. When a transient negative pressure occurs in the third degassing tank 23, the gas drawn into the third degassing tank 23 through the fourth connecting tank 34 mainly comes from the return flow of the low-hydrogen-content exhaust gas, rather than external ambient air. Since this return gas mainly consists of a large amount of nitrogen and a small amount of hydrogen, its chemical properties are stable and it is not easily reactive with the molten aluminum, significantly reducing the risk of aluminum oxidation. This equipment achieves effective utilization of the low-hydrogen-content exhaust gas in this way. This equipment uses low-hydrogen-content exhaust gas to degas high-hydrogen-content molten aluminum, and utilizes the low-hydrogen-content exhaust gas to form a protective gas curtain at the fourth connecting tank 34, realizing the cascade utilization of exhaust gas. The cover plate 5 has an air outlet 50 aligned with the first degassing tank 21, and the exhaust gas from the first degassing tank 21 is discharged to the outside through the air outlet 50.

[0029] See Figure 1This equipment includes a vertical linear module 91, which is existing technology. A mounting bracket 92 is installed on its drive block 911, and the cover plate 5 is mounted on the mounting bracket 92. The linear module 91 and the mounting bracket 92 serve as a lifting mechanism. The equipment also includes a drive mechanism 93 for the degassing box 1, which is existing technology. After degassing, no more molten aluminum flows into the degassing box 1. The operator stops the nitrogen pump, each drive motor 602, and each booster pump 81 and 82, and then controls the linear module 91 to drive the mounting bracket 92 to lift the cover plate 5. Figure 5 As shown, this causes the cover plate 5 and its components to rise until the hollow rotor 601 on the cover plate 5 rises to a position 1-2 meters above the degassing box 1. During this process, the plugs 51 and 52 on the cover plate 5 move away from the second and third connecting grooves 32 and 33, thus no longer blocking these two connecting grooves 32 and 33. See Figure 6 The staff moved the front and rear blocking blocks 41 and 42 to the liquid inlet 155 at the rear end of the flow channel 15, and then controlled the drive mechanism 93 to drive the degassing box 1 to slowly rotate to the left to a tilted state to pour out the residual aluminum liquid in the three degassing tanks 21, 22, 23 and the waste gas utilization tank 20. Specifically, the aluminum liquid remaining in the waste gas utilization tank 20 and the three degassing tanks 21, 22, 23 was poured into the flow channel 15 from the four connecting tanks 31, 32, 33, 34. Due to the obstruction of the front and rear blocking blocks 41 and 42, it could not flow backward, but could only flow forward from the liquid outlet 156 at the front end of the flow channel 15 to the liquid outlet guide tank 72.

[0030] Second embodiment:

[0031] The second embodiment is largely the same as the first embodiment, except that:

[0032] See the second embodiment. Figure 7 A hollow insulation layer 73 made of alumina ceramic material is wrapped around the outer periphery of the liquid outlet guide channel 72. A vent pipe 58 is detachably connected to the rear section of the hollow insulation layer 73 at the vent 50. An exhaust port is located at the front section of the hollow insulation layer 73 (not shown in the figure due to perspective). The first degassing channel 21 (see...) Figure 3 The exhaust gas is not discharged to the outside through the vent 50, but instead flows from the vent 50 to the vent pipe 58. Guided by the vent pipe 58, it flows into the hollow insulation layer 73 and then forward along the hollow insulation layer 73, finally being discharged to the outside through the exhaust port. During this process, the heat of the exhaust gas is transferred through the hollow insulation layer 73 to the liquid outlet guide trough 72, and then from the liquid outlet guide trough 72 to the aluminum liquid, which can have a heat preservation effect on the aluminum liquid on the liquid outlet guide trough 72. Before the drive mechanism 93 drives the degassing box 1 to rotate to the left to pour out the remaining aluminum liquid, the operator should remove the vent pipe 58 from the vent 50 to prevent the vent pipe 58 from affecting the liquid pouring of the degassing box 1.

[0033] The above description is merely an embodiment of the present invention and does not limit the scope of patent protection. Any non-substantial changes or substitutions made by those skilled in the art based on the present invention will still fall within the scope of patent protection.

Claims

1. An online degassing device for cascade utilization of molten aluminum, comprising a degassing box, the degassing box having multiple degassing tanks arranged in parallel, the rearmost degassing tank being connected to the outside for undegassed molten aluminum to flow into the tank, the device having a gas supply mechanism to provide inert gas to each degassing tank to remove hydrogen from the molten aluminum in each degassing tank, and the frontmost degassing tank having an outlet tank on its wall connected to the outside for the degassed molten aluminum to flow out of the tank, characterized in that: The degassing box is also equipped with a waste gas utilization tank. The rearmost degassing tank is connected to the outside through the waste gas utilization tank. This equipment is equipped with a first air pump and a second air pump. The first air pump draws the waste gas from the frontmost degassing tank to the waste gas utilization tank to remove hydrogen from the aluminum liquid in the waste gas utilization tank. The pumping flow rate of the first air pump is less than the flow rate of inert gas input by the gas supply mechanism to the frontmost degassing tank. The second air pump draws the waste gas from the degassing tank adjacent to the frontmost degassing tank to the liquid outlet tank to form an air curtain.

2. The online degassing equipment for molten aluminum according to claim 1, characterized in that: There are three degassing tanks, arranged from back to front. The waste gas utilization tank is located behind the first degassing tank. The left wall of the waste gas utilization tank has a liquid inlet tank, which connects to the outside world. The bottom of the partition between the waste gas utilization tank and the first degassing tank has a first through hole connecting the two tanks. The top of the partition between the first and second degassing tanks has a second through hole connecting the two tanks. The bottom of the partition between the second and third degassing tanks has a third through hole connecting the two tanks.

3. The online degassing equipment for molten aluminum according to claim 2, characterized in that: The liquid outlet tank is specifically located on the left wall of the third degassing tank, supplying the aluminum liquid in the tank to flow to the left. The degassing tank is equipped with a cover plate that covers the waste gas utilization tank and the three degassing tanks. The cover plate extends downwards and has a protrusion that sinks into the top of the liquid outlet tank. The cover plate has an air supply channel. The liquid inlet end of the air supply channel is connected to the second air pump, and the liquid outlet end extends to the left wall of the protrusion and is a strip in the front-to-back direction.

4. The online degassing equipment for molten aluminum according to claim 3, characterized in that: A liquid outlet guide channel is provided to connect to the liquid outlet tank, guiding the degassed aluminum liquid to the casting equipment; a hollow insulation layer is provided on the outer periphery of the liquid outlet guide channel, and an air outlet hole is opened on the cover plate. An air guide pipe is provided at the air outlet hole to connect to the hollow insulation layer, guiding the waste gas of the first degassed tank to the hollow insulation layer, thereby insulating the liquid outlet guide channel.

5. The online degassing equipment for molten aluminum according to claim 3, characterized in that: A drive mechanism is provided to rotate the degassing box to an inclined state, thereby emptying the waste gas utilization tank and the residual aluminum liquid in each degassing tank.

6. The online degassing equipment for molten aluminum according to claim 5, characterized in that: The left side of the box has a flow channel running in the front-to-back direction. The rear end of the flow channel is the liquid inlet for undegassed aluminum liquid to flow into the flow channel, and the front end of the flow channel is the liquid outlet for degassed aluminum liquid to be discharged out of the flow channel. The liquid inlet and liquid outlet channels are respectively connected to the front and rear sections of the flow channel to the left. A block is installed on the flow channel, located between the liquid inlet and liquid outlet channels. The block can be moved to the liquid inlet at the rear end of the flow channel. The drive mechanism drives the degassing box to rotate to the left to pour out the residual aluminum liquid in the waste gas utilization channel and each degassing channel. When the block is moved to the liquid inlet at the rear end of the flow channel and the drive mechanism drives the degassing box to rotate to the left, the residual aluminum liquid in the waste gas utilization channel and the third degassing channel is poured into the flow channel through the liquid inlet and liquid outlet channels, respectively.

7. The online degassing equipment for molten aluminum according to claim 6, characterized in that: The left wall of the first and second degassing tanks has two parallel connecting channels facing each other to the middle of the left connecting channel. The cover plate extends downwards and has two plugs that block the two connecting channels respectively. There are two plugs, one in front and one in back. The back plug is located between the liquid inlet tank and the rear connecting channel, and the front plug is located between the liquid outlet tank and the front connecting channel. A lifting mechanism is provided to lift the cover plate so that the two plugs no longer block the two connecting channels. Both plugs are moved to the liquid inlet at the rear end of the channel, and the drive mechanism drives the degassing box to rotate to an inclined state after the cover plate is lifted. The residual aluminum liquid in the first and second degassing tanks is poured from the two connecting channels into the channel respectively.

8. The online degassing equipment for molten aluminum according to claim 2, characterized in that: The cover plate is equipped with a first, second, and third degassing unit. The gas supply mechanism is connected to these three degassing units and provides them with inert gas. The three degassing units respectively input the inert gas into the bottom of the three degassing tanks to remove hydrogen from the molten aluminum in the three degassing tanks. The cover plate is also equipped with a fourth degassing unit. The first air pump draws the waste gas from the third degassing tank to the fourth degassing unit. The fourth degassing unit inputs the waste gas into the bottom of the waste gas utilization tank to remove hydrogen from the molten aluminum in the waste gas utilization tank.

Images