A small-scale laboratory tail gas absorption and treatment device for phosphine analysis

Abstract

This invention discloses a small-scale laboratory phosphine analysis tail gas absorption and treatment device, comprising an analytical instrument and a packed tower. The analytical instrument is connected to a gas cylinder at its inlet and has an exhaust pipe. The packed tower contains multiple layers of packing material and a liquid storage tank at the bottom, containing an alkaline solution. The other end of the exhaust pipe is connected to the throat of a gas venturi, the inlet of which is connected to an inert gas supply device, and the outlet of which is connected to the upper end of a buffer tube. This invention features a novel structure and reasonable design, effectively ensuring a negative pressure state in the exhaust pipe while effectively preventing liquid backflow and avoiding damage to the equipment caused by pressure buildup and backflow. Furthermore, through the dilution and preliminary absorption of phosphine, the safety and treatment effect of phosphine treatment are effectively ensured. The combination of multiple layers of packing material and spraying ensures complete absorption of phosphine, guaranteeing the treatment effect.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology, and in particular to a small-scale laboratory exhaust gas absorption and treatment device for phosphine analysis. Background Technology

[0002] Ultrapure phosphine is used in the epitaxial growth and doping processes of electronic chips such as LEDs, chips, and panels. Quality control of ultrapure phosphine is becoming increasingly important. During the analysis process, a certain amount of phosphine will be emitted, and the concentration of emitted phosphine varies greatly. This part of the emission is generally independent of the production emission to avoid mutual interference.

[0003] Existing exhaust gas absorption and treatment devices cannot effectively absorb phosphine of different concentrations, and cannot guarantee stable pressure in the emission pipeline, which can easily cause pressure buildup in the emission pipeline, damage the equipment, and affect the safety of phosphine treatment. At the same time, they cannot guarantee complete absorption of phosphine, resulting in poor treatment effect. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as inability to adapt to different concentrations of phosphine emissions, easy pressure buildup in emission pipelines, easy damage to equipment and impact on the safety of phosphine treatment, inability to guarantee complete absorption of phosphine, and poor treatment effect. Therefore, this invention proposes a small-scale laboratory phosphine analysis tail gas absorption and treatment device.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A small laboratory phosphine analysis tail gas absorption and treatment device includes an analytical instrument and a packed tower. The analytical instrument is connected to a gas cylinder at its inlet end and is equipped with an exhaust pipe. The packed tower contains multiple layers of packing material and a liquid storage tank at the bottom, which contains an alkaline solution.

[0007] The other end of the discharge pipeline is connected to the throat of a gas venturi. The gas inlet of the gas venturi is connected to an inert gas supply device. The outlet of the gas venturi is connected to the upper end of a buffer tube. A liquid venturi is connected to the throat of a liquid venturi through a pipe on the side wall of the buffer tube. The liquid inlet of the liquid venturi is connected to a first liquid pump. The liquid inlet of the first liquid pump is connected to a liquid storage tank. The liquid outlet of the liquid venturi is connected to the lower part of the packed tower.

[0008] A second liquid pump is also connected to one side of the liquid storage tank. The outlet end of the second liquid pump is equipped with multiple branch pipes, each of which passes through the side wall of the packed tower and is equipped with multiple spray heads. The spray heads located at the bottom spray upwards, while the spray heads at the top spray downwards.

[0009] Preferably, the lower end of the buffer tube is provided with a drain outlet, the drain outlet is provided with a drain valve, and the lower part of the side wall of the buffer tube is provided with multiple observation windows.

[0010] Preferably, a pressure gauge is also provided between the buffer tube and the liquid venturi.

[0011] Preferably, the packed tower has five sections, wherein the lower end of the first section is located below the surface of the alkali solution, the packing is located in the second, fourth and fifth sections, and the fifth section is in the shape of an inverted funnel. A fan is connected to the top of the fifth section through a pipe.

[0012] More preferably, a vertically arranged condensation pipe is provided between the packed tower and the blower, the side wall of the condensation pipe is connected to the blower, the lower end of the condensation pipe is provided with a liquid outlet, and a collection tank is provided below the liquid outlet.

[0013] More preferably, the fan has a vertically penetrating discharge pipe at its outlet end, and the lower end of the discharge pipe also has an outlet.

[0014] Preferably, the side wall of the packed tower is provided with multiple inspection ports corresponding to the packing.

[0015] Preferably, the side wall of the packed tower is also provided with multiple viewing windows, and multiple cleaning nozzles are provided on multiple branch pipes corresponding to the viewing windows.

[0016] Preferably, the liquid storage tank is provided with a feeding port and a water replenishment port, the other end of the water replenishment port is connected to a water supply device, and a drain port is also provided through the lower part of the side wall of the liquid storage tank.

[0017] Preferably, the storage tank is also equipped with a level gauge and multiple pH meters, and a partition is vertically provided on the inner wall of the storage tank near the second liquid pump, with the upper end of the partition located below the surface of the alkaline solution.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] 1. In this invention, by designing gas Venturi and liquid Venturi, a negative pressure state is maintained in the discharge pipeline to avoid damage to the equipment in the discharge pipeline caused by pressure buildup. At the same time, it can dilute and preliminarily absorb phosphine, effectively improving the safety and absorption effect of phosphine tail gas treatment.

[0020] 2. In this invention, the design of the buffer tube ensures that the gas pressure remains uniform, preventing the alkaline solution in the liquid venturi from flowing back into the discharge pipeline. At the same time, when there is liquid backflow, the liquid can be easily discharged, ensuring the stable use of the absorption device.

[0021] 3. In this invention, the multi-layer packed tower design effectively prevents phosphine from overflowing from the bottom of the packed tower, ensuring safe use. At the same time, the packing and spray heads work together to absorb the phosphine, ensuring the absorption and treatment effect of the phosphine and guaranteeing complete absorption.

[0022] 4. In this invention, the upward spray head design ensures that the spray direction of the alkaline solution droplets is the same as the upward direction of the phosphine, thereby extending the contact time between the phosphine and the alkaline solution and ensuring the absorption effect of the phosphine.

[0023] This invention features a novel structure and a reasonable design, effectively ensuring a negative pressure state in the discharge pipeline while effectively preventing liquid backflow and avoiding damage to the equipment caused by pressure buildup and backflow. Furthermore, through the dilution and preliminary absorption of phosphine, it effectively ensures the safety and treatment effect of phosphine treatment. Combined with multi-layer packing and spraying, it ensures the complete absorption of phosphine and guarantees the treatment effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a schematic diagram of the discharge pipeline and buffer pipe structure of the present invention;

[0026] Figure 3 This is a schematic diagram of the liquid venturi and storage tank structure of the present invention;

[0027] Figure 4 This is a schematic diagram of the packed tower structure of the present invention;

[0028] Figure 5 This is a schematic diagram of the condensation pipe and discharge pipe structure of the present invention.

[0029] In the diagram: Analytical instrument 1, gas cylinder 101, discharge pipeline 102, gas venturi 2, liquid venturi 3, pressure gauge 31, buffer tube 4, drain outlet 41, observation window 42, packed tower 5, packing 51, inspection port 511, viewing window 52, ​​storage tank 6, feed port 61, drain outlet 62, water inlet 63, level gauge 64, pH meter 65, baffle 66, first liquid pump 7, second liquid pump 8, branch pipe 81, spray head 811, cleaning spray head 812, condensation pipe 9, liquid outlet 91, collection tank 92, fan 10, discharge pipe 11, discharge outlet 111. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. The hollow arrows in the drawings indicate the gas flow direction and the solid arrows in the drawings indicate the liquid flow direction. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] Example 1

[0033] Reference Figure 1-5 A small laboratory phosphine analysis tail gas absorption and treatment device includes an analytical instrument 1 and a packed tower 5. The analytical instrument 1 is connected to a gas cylinder 101 at its inlet end for storing and supplying phosphine. The analytical instrument 1 is equipped with an exhaust pipe 102. The packed tower 5 contains multiple layers of packing material 51, which can be made of PVC, PP, etc. The packing material 51 blocks the rising gas, reduces the rising speed of the gas, and improves the absorption and treatment effect of the gas. A liquid storage tank 6 is provided below, which contains an alkaline solution, which can be a mixed solution of 5% NaOH and 5% NaClO.

[0034] The other end of the discharge pipe 102 is connected to the throat of the gas venturi 2. The inlet end of the gas venturi 2 is connected to an inert gas supply device, wherein the inert gas can be nitrogen. The outlet end of the gas venturi 2 is connected to the upper end of the buffer pipe 4. The throat of the liquid venturi 3 is connected through a pipe on the side wall of the buffer pipe 4. The inlet end of the liquid venturi 3 is connected to the first liquid pump 7. The inlet end of the first liquid pump 7 is connected through the liquid storage tank 6. The outlet end of the liquid venturi 3 is connected through the lower part of the packed tower 5.

[0035] By introducing nitrogen gas and utilizing the Venturi effect of the gas Venturi 2, the phosphine in the discharge pipe 102 is drawn into the gas Venturi 2 and sent into the buffer pipe 4, ensuring a negative pressure state in the discharge pipe 102. This prevents pressure buildup from damaging the vacuum pump and other equipment in the discharge pipe 102, and also ensures stable pressure at the GC detector and other equipment in the discharge pipe 102, thus guaranteeing the effectiveness of the discharge pipe 102.

[0036] This also ensures the complete absorption of the small amount of phosphine emitted during the analysis process, and uses nitrogen to dilute the phosphine. Since the concentration of emitted phosphine varies greatly, safety is effectively improved. At the same time, the buffer tube 4 is used to prevent the alkali solution from flowing back. The refluxed alkali solution is blocked and retained in the buffer tube 4. The diluted phosphine is drawn into the liquid venturi 3 by the negative pressure generated by the liquid venturi 3 and mixed with the pumped alkali solution for preliminary absorption. The phosphine is then sent to the packed tower 5 for further absorption.

[0037] A second liquid pump 8 is also connected to one side of the storage tank 6. The outlet end of the second liquid pump 8 is provided with multiple branch pipes 81. Each branch pipe 81 passes through the side wall of the packed tower 5 and is provided with multiple spray heads 811. The lower spray head 811 sprays upward, and the uppermost spray head 811 sprays downward. The second liquid pump 8 pumps the alkaline solution into the spray head 811 for spraying. The phosphine is absorbed by the alkaline solution in the packing 51 through the spraying, ensuring complete absorption. At the same time, the upward spray head 811 makes the droplet direction the same as the upward direction of the phosphine, prolonging the contact time between the alkaline droplets and the phosphine, and improving the absorption effect of the phosphine.

[0038] When this exhaust gas absorption and treatment device is in use, the phosphine emitted during the analysis process of the analyzer 1 is discharged through the discharge pipeline 102. The discharge pipeline 102 is equipped with a vacuum pump, GC detector and other equipment. By introducing nitrogen into the gas venturi 2 inlet, the discharge pipeline 102 is kept under negative pressure to ensure the absorption and dilution effect of phosphine and improve the safety of phosphine emission. After dilution, the phosphine passes through the buffer tube 4 and then enters the liquid venturi 3 through the negative pressure generated by the liquid venturi 3 to mix with the alkaline solution for preliminary absorption treatment of phosphine.

[0039] Using the buffer tube 4 can effectively prevent the alkaline solution in the liquid venturi 3 from flowing back into the discharge pipe 102, thus avoiding damage to the equipment in the discharge pipe 102 and effectively improving the safety of the absorption device.

[0040] By using gaseous Venturi 2 and liquid Venturi 3, a negative pressure state is maintained in the discharge pipeline 102, which effectively avoids pressure buildup in the discharge pipeline 102, protects the equipment in the discharge pipeline 102, and also dilutes and pre-absorbs phosphine, effectively improving the effect and safety of phosphine absorption and treatment.

[0041] In this embodiment, as Figure 1-3 As shown, the lower end of the buffer tube 4 is provided with a drain outlet 41, and a drain valve is provided on the drain outlet 41. The lower part of the side wall of the buffer tube 4 is provided with multiple observation windows 42. The buffer tube 4 prevents the backflow of alkaline solution from affecting the discharge pipeline 102 and the analysis instrument 1. The water accumulation status in the buffer tube 4 can be observed through the observation windows 42. When there is water accumulation in the buffer tube 4, the alkaline solution in the buffer tube 4 is sent out through the drain valve.

[0042] In this embodiment, as Figure 1-3 As shown, a pressure gauge 31 is also provided between the buffer tube 4 and the liquid venturi 3 to detect the gas pressure sent into the liquid venturi 3 and maintain the gas pressure at 1 to 4 bar to ensure a certain gas pressure so that the discharged phosphine can be stably delivered, avoiding pressure buildup that could affect the discharge of the discharge pipe 102, and also effectively preventing the backflow of alkali solution.

[0043] Example 2

[0044] Reference Figure 1-5 In this embodiment, it is basically the same as in Embodiment 1, but with an optimization: the packed tower 5 is provided with five sections. The lower end of the first section from bottom to top is set below the surface of the alkaline solution to prevent phosphine from overflowing from the lower end of the packed tower 5 and to ensure the safety of phosphine treatment. The packing 51 is set in the second, fourth and fifth sections to block the upward flow of phosphine gas, slow down the upward speed of phosphine, ensure complete absorption of phosphine, and improve the absorption effect of phosphine. The fifth section is shaped like an inverted funnel to ensure complete absorption of phosphine and facilitate the discharge of residual gas. A fan 10 is connected to the top of the fifth section through a pipe to discharge the gas after the phosphine has been completely removed.

[0045] In this embodiment, as Figure 1-4 As shown, the side wall of the packed tower 5 is provided with multiple inspection ports 511 corresponding to the packing 51, which facilitates the inspection of the status of the packing 51, as well as the replenishment and replacement of the packing 51, and facilitates the maintenance of the packed tower 5.

[0046] In this embodiment, as Figure 1-4 As shown, the side wall of the packed tower 5 is also provided with multiple viewing windows 52 to monitor the working status of the packed tower 5. Multiple branch pipes 81 are provided with multiple cleaning nozzles 812 corresponding to the viewing windows 52. When the spray nozzles 811 absorb phosphine, the generated reactant solids will accumulate on the viewing windows 52, affecting the use of the viewing windows 52. The viewing windows 52 are cleaned by the cleaning nozzles 812 to avoid the adhesion of reactants and ensure the effectiveness of the viewing windows 52.

[0047] Example 3

[0048] Reference Figure 1-3 In this embodiment, it is basically the same as in Embodiment 1, but with an optimization: the liquid storage tank 6 is provided with a feeding port 61 and a water inlet 63. The other end of the water inlet 63 is connected to a water supply device. A drain port 62 is also provided through the lower part of the side wall of the liquid storage tank 6. NaOH and NaClO are added to the liquid storage tank 6 through the feeding port 61, and clean water is added at the same time in conjunction with the water inlet 63 to ensure stable liquid level and facilitate pH adjustment. The drain port 62 is used to discharge the solid reactants accumulated in the liquid storage tank 6 to ensure stable use of the liquid storage tank 6.

[0049] In this embodiment, as Figure 1-3As shown, the storage tank 6 is also equipped with a level gauge 64 and multiple pH meters 65. A partition 66 is vertically installed on the inner wall of the storage tank 6 near the second liquid pump 8, and the upper end of the partition 66 is below the surface of the alkali solution. The level gauge 64 monitors the level of the alkali solution to ensure a stable level and prevent the alkali solution level from dropping below the lower end of the packed tower 5, thus ensuring the effectiveness of the packed tower 5. At the same time, the pH meters 65 monitor the pH value of the alkali solution to facilitate the addition of reagents. The partition 66 is used to separate the reactants from the inlet of the second liquid pump 8 to prevent solid reactants from entering the spray head 811 and the cleaning spray head 812 and causing blockage.

[0050] Example 4

[0051] Reference Figure 1-5 In this embodiment, it is basically the same as in Embodiment 1, but with an optimization: a vertically arranged condensation pipe 9 is provided between the packed tower 5 and the blower 10. The side wall of the condensation pipe 9 is connected to the blower 10. The lower end of the condensation pipe 9 is provided with a liquid outlet 91, and a liquid outlet valve is provided on the liquid outlet 91. A collection tank 92 is provided below the liquid outlet 91. The gas emitted by the packed tower 5 contains a lot of water vapor. The water vapor condenses into water droplets in the condensation pipe 9 and flows down. When the water accumulates, the liquid outlet valve is opened and the water is sent into the collection tank 92 through the liquid outlet 91, which facilitates subsequent environmental protection treatment and avoids direct discharge that will affect the environment.

[0052] In this embodiment, as Figure 1 and 5 The fan 10 has a vertically penetrating discharge pipe 11 at its air outlet end, and the lower end of the discharge pipe 11 is also provided with an outlet 111. The treated gas is discharged through the discharge pipe 11. When the water droplets and rainwater condensed during the discharge of the discharge pipe 11 enter the discharge pipe 11, the water in them is discharged through the outlet 111.

[0053] In this invention, corresponding valves are provided on the pipeline as needed. For example, a one-way valve can be installed between the gas venturi 2 and the buffer tube 4, which will not be elaborated on here.

[0054] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A small-scale laboratory tail gas absorption and treatment device for phosphine analysis, comprising an analytical instrument (1) and a packed tower (5), characterized in that, The analyzer (1) has a gas cylinder (101) connected to its inlet end, and an exhaust pipe (102) is provided on the analyzer (1). The packed tower (5) has multiple layers of packing (51) inside, and a liquid storage tank (6) is provided below it. The liquid storage tank (6) contains alkali solution. The other end of the discharge pipeline (102) is connected to the throat of the gas venturi (2). The gas venturi (2) inlet is connected to the inert gas supply equipment. The gas venturi (2) outlet is connected to the upper end of the buffer pipe (4). The buffer pipe (4) sidewall is connected to the throat of the liquid venturi (3) through a pipe. The liquid venturi (3) inlet is connected to the first liquid pump (7). The liquid pump (7) inlet is connected to the liquid storage tank (6). The liquid venturi (3) outlet is connected to the lower part of the packed tower (5). The storage tank (6) is also connected to a second liquid pump (8) on one side. The outlet end of the second liquid pump (8) is provided with multiple branch pipes (81). Each branch pipe (81) passes through the side wall of the packed tower (5) and is provided with multiple spray heads (811). The spray head (811) located at the bottom sprays upward, and the spray head (811) located at the top sprays downward.

2. The laboratory-scale small-scale phosphine analysis tail gas absorption and treatment device according to claim 1, characterized in that, The buffer tube (4) has a drain outlet (41) at its lower end, a drain valve on the drain outlet (41), and multiple observation windows (42) on the lower part of the side wall of the buffer tube (4).

3. The laboratory-scale small-scale phosphine analysis tail gas absorption and treatment device according to claim 1, characterized in that, A pressure gauge (31) is also provided between the buffer tube (4) and the liquid venturi (3).

4. The laboratory-scale small-scale phosphine analysis tail gas absorption and treatment device according to claim 1, characterized in that, The packed tower (5) has five sections. The lower end of the first section is set below the surface of the alkali solution. The packing (51) is set in the second, fourth and fifth sections. The fifth section is in the shape of an inverted funnel. A blower (10) is connected to the top of the fifth section through a pipe.

5. A small-scale laboratory tail gas absorption and treatment device for phosphine analysis according to claim 4, characterized in that, A vertically arranged condensation pipe (9) is provided between the packed tower (5) and the blower (10). The side wall of the condensation pipe (9) is connected to the blower (10). A liquid outlet (91) is provided at the lower end of the condensation pipe (9), and a collection tank (92) is provided below the liquid outlet (91).

6. A small-scale laboratory tail gas absorption and treatment device for phosphine analysis according to claim 4, characterized in that, The fan (10) has a vertically penetrating discharge pipe (11) at the air outlet end, and the lower end of the discharge pipe (11) also has an outlet (111).

7. The laboratory-scale small-scale phosphine analysis tail gas absorption and treatment device according to claim 1, characterized in that, The packed tower (5) has multiple inspection ports (511) on its side wall corresponding to the packing (51).

8. The laboratory-scale small-scale phosphine analysis tail gas absorption and treatment device according to claim 1, characterized in that, The packing tower (5) is also provided with multiple viewing windows (52) on its side wall, and multiple cleaning nozzles (812) are provided on multiple branch pipes (81) corresponding to the viewing windows (52).

9. A small-scale laboratory tail gas absorption and treatment device for phosphine analysis according to claim 1, characterized in that, The liquid storage tank (6) is provided with a feeding port (61) and a water inlet (63). The other end of the water inlet (63) is connected to a water supply device. A drain outlet (62) is also provided through the lower part of the side wall of the liquid storage tank (6).

10. A small-scale laboratory tail gas absorption and treatment device for phosphine analysis according to claim 1, characterized in that, The storage tank (6) is also equipped with a level gauge (64) and multiple pH meters (65). A partition (66) is vertically provided on the inner wall of the storage tank (6) near the second liquid pump (8), and the upper end of the partition (66) is below the surface of the alkaline solution.

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