A device for treating tail gas from phosphorus fluoride processing

Abstract

The invention relates to the separation of harmful substances in tail gas, and discloses a tail gas treatment device for phosphorus fluoride processing, comprising: a spray purification box, wherein one end surface of the spray purification box is provided with an air inlet; an air outlet, which is arranged on the other end surface of the spray purification box, and the inner side of the air outlet is provided with a fan; a first partition; a second partition, which is arranged side by side with the first partition along the long side of the spray purification box, and the ends of the second partition and the first partition are staggered to form an air flow channel; by providing the fan, the second partition, the first partition, a porous filler and a supporting mesh plate, the device is convenient for extending the walking route of the tail gas inside the spray purification box, so that the tail gas can better fill the spray purification box, thereby ensuring the contact effect between alkali solution and tail gas, improving the absorption of harmful substances in the tail gas by the alkali solution, and being able to increase the reaction temperature inside the spray purification box, reduce the influence of low temperature on absorption, and provide adsorption and removal of harmful substances through activated carbon plates.

Description

Technical Field

[0001] The invention relates to the separation of harmful substances in tail gas, and in particular to a tail gas treatment device for phosphorus fluoride processing. Background Art

[0002] Phosphorus fluoride is an important chemical substance. As a fluorine-containing chemical reagent, it can react with other elements to form volatile gas molecules. In the processing of semiconductor materials, phosphorus fluoride is often used in vapor deposition processes, or used together with other gases such as hydrogen fluoride to etch materials on the surface of metals or semiconductors. Phosphorus fluoride can also participate in the reaction of preparing fluorine-containing films. These films have important functions in some special semiconductor devices. However, when phosphorus fluoride is used or processed, it is usually mixed with hydrogen fluoride, phosphine and other toxic and harmful compounds. In order to remove harmful substances, alkaline solution is sprayed through a spray tower during treatment to absorb harmful substances in the tail gas.

[0003] When the existing phosphorus fluoride tail gas is removed by spraying, the tail gas moves straight up in the spray tower, and the purified air is discharged from the top of the tower. The straight upward movement of the tail gas cannot fill the space in the spray tower well, resulting in waste of gaps in the internal space, and the contact effect between the alkali solution and the tail gas is not good. In addition, the straight upward movement of the tail gas causes the flow path in the tower to be shorter, which also affects the contact area of ​​the alkali solution with the tail gas and affects the absorption of harmful substances. For this reason, we propose a phosphorus fluoride processing tail gas treatment device. Summary of the invention

[0004] The object of the present invention is to provide a phosphorus fluoride processing tail gas treatment device to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a phosphorus fluoride processing tail gas treatment device, comprising:

[0006] A spray purification box, wherein an air inlet is provided on one end surface of the spray purification box;

[0007] An air outlet is arranged on the other end surface of the spray purification box, and a fan is provided inside the air outlet;

[0008] First bulkhead;

[0009] A second partition is arranged side by side with the first partition along the long side of the spray purification box, and the second partition is staggered with the end of the first partition to form an air flow channel;

[0010] A supporting mesh plate, fixed between two adjacent first separators, and having a porous filler on the supporting mesh plate;

[0011] The spray assembly is arranged at the top of the inner side of the spray purification box to spray the alkaline solution that absorbs harmful substances in the tail gas from top to bottom.

[0012] Preferably, the spray assembly includes a circulation pump group, a liquid suction pipe, a liquid outlet pipe, a spray pipe and a spray head. The spray pipe is fixed to the top inner side of the spray purification box, and the spray head is installed on the lower surface of the spray pipe. The circulation pump group is arranged on the upper surface of the spray purification box, and one side of the circulation pump group has a liquid outlet pipe connected to the inner side of the spray pipe. The liquid suction pipe is arranged on the front surface of the circulation pump group, and one end of the circulation pump group passes through the spray purification box and is connected to the liquid storage tank arranged on the inner side of the spray purification box.

[0013] Preferably, the spray pipes are evenly distributed at three locations along a short side of the spray purification box, and the spray heads are evenly distributed at multiple locations along the axial direction of each spray pipe.

[0014] Preferably, the inner wall of the liquid storage tank is provided with scale lines flush with the supporting mesh plate.

[0015] Preferably, an activated carbon plate is disposed on the side wall of the second partition, and a through hole is opened on the inner side of the activated carbon plate.

[0016] Preferably, mounting bolts connected to the second partition plate are provided at the four inner corners of the activated carbon plate.

[0017] Preferably, a heating wire is arranged on the inner side of the first partition along its long side.

[0018] Preferably, the porous filler is made of bauxite or zeolite.

[0019] Preferably, the spray purification box is rectangular, and the number of the first partitions is equal to the number of the second partitions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] By providing a fan, a second baffle, a first baffle, a porous filler and a supporting mesh plate, it is avoided that the exhaust gas cannot fill the space inside the spray tower well, resulting in a waste of free space in the spray tower, poor contact effect between the alkali solution and the exhaust gas, and affecting purification. The device is convenient for extending the walking path of the exhaust gas on the inside of the spray purification box, so that the exhaust gas can better fill the spray purification box, thereby ensuring the contact effect between the alkali solution and the exhaust gas, improving the absorption of harmful substances in the exhaust gas by the alkali solution, and can increase the reaction temperature inside the spray purification box, reduce the influence of low temperature on absorption, provide adsorption and removal of harmful substances through the activated carbon plate, and increase the practicality of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the fan of the present invention;

[0024] Figure 3 It is a schematic diagram of the cross-sectional structure of the spray purification box of the present invention;

[0025] Figure 4 It is a schematic diagram of the heating wire structure of the present invention;

[0026] Figure 5 It is a schematic diagram of the structure of the activated carbon plate of the present invention.

[0027] In the figure: 1. spray purification box; 2. air inlet; 3. air outlet; 4. fan; 501. circulation pump group; 502. liquid extraction pipe; 503. liquid outlet pipe; 504. spray pipe; 505. spray head; 6. first partition; 7. second partition; 8. liquid storage tank; 9. porous filler; 10. support mesh plate; 11. air flow channel; 12. heating wire; 13. activated carbon plate; 14. through hole; 15. mounting bolts. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-Figure 5 The present invention provides a technical solution: a phosphorus fluoride processing tail gas treatment device, comprising:

[0030] A spray purification box 1, one end surface of which is provided with an air inlet 2;

[0031] The air outlet 3 is arranged at the other end surface of the spray purification box 1, and a fan 4 is provided inside the air outlet 3 to facilitate the discharge of the purified exhaust gas to the outside;

[0032] A first partition 6;

[0033] The second partition plate 7 is arranged side by side with the first partition plate 6 along the long side of the spray purification box 1, and the ends of the second partition plate 7 and the first partition plate 6 are staggered to form an air flow channel 11, which is convenient for extending the route of the exhaust gas in the spray purification box 1, thereby increasing the contact area between the exhaust gas and the spray liquid;

[0034] The supporting mesh plate 10 is fixed between two adjacent first partition plates 6, and the supporting mesh plate 10 is provided with a porous filler 9, so as to further increase the contact surface area between the exhaust gas and the spray liquid, thereby improving the purification effect of the exhaust gas;

[0035] The spray assembly is arranged at the top of the inner side of the spray purification box 1 to spray the alkali solution for absorbing harmful substances in the tail gas from top to bottom, so as to remove the acidic gases such as hydrogen fluoride in the tail gas of the phosphorus fluoride processing by the alkali solution. The alkali solution is preferably a sodium hydroxide solution or a calcium hydroxide solution.

[0036] Preferably, the spray assembly includes a circulation pump group 501, a liquid extraction pipe 502, a liquid outlet pipe 503, a spray pipe 504 and a spray head 505. The spray pipe 504 is fixed to the top inner side of the spray purification box 1, and the spray head 505 is installed on the lower surface of the spray pipe 504. The circulation pump group 501 is arranged on the upper surface of the spray purification box 1, and one side of the circulation pump group 501 has a liquid outlet pipe 503 connected to the inner side of the spray pipe 504. The liquid extraction pipe 502 is arranged on the front surface of the circulation pump group 501, and one end of the circulation pump group 501 passes through the spray purification box 1 and is connected to the liquid storage tank 8 arranged on the inner side of the spray purification box 1, so as to facilitate the recycling of the alkali solution, reduce waste, and reduce the purification cost of exhaust gas treatment.

[0037] Preferably, three spray pipes 504 are evenly distributed along a short side of the spray purification box 1, and multiple spray heads 505 are evenly distributed along the axial direction of each spray pipe 504, so as to increase the atomization area of ​​the spray liquid, thereby improving the contact treatment effect between the spray liquid and the exhaust gas.

[0038] Preferably, the inner wall of the liquid storage tank 8 is provided with scale lines flush with the supporting mesh plate 10 to prevent the exhaust gas from flowing inside the liquid storage tank 8 to the gas outlet 3 of the spray purification box 1 .

[0039] Preferably, an activated carbon plate 13 is disposed on the side wall of the second separator 7, and a through hole 14 is opened inside the activated carbon plate 13 to facilitate the adsorption and removal of harmful substances in the exhaust gas.

[0040] Preferably, mounting bolts 15 connected to the second partition plate 7 are provided at the four inner corners of the activated carbon plate 13 to facilitate the later disassembly, replacement and maintenance of the activated carbon plate 13 .

[0041] Preferably, a heating wire 12 is provided inside the first partition plate 6 along its long side to increase the temperature of the reaction and improve the dissolution effect of harmful substances in the tail gas in the spray liquid.

[0042] Preferably, the porous filler 9 is made of bauxite or zeolite, so as to better adsorb hydrogen fluoride and phosphine gases in the tail gas.

[0043] Preferably, the spray purification box 1 is rectangular, and the number of the first partitions 6 and the second partitions 7 are equal, so that the exhaust gas can better fill the inside of the spray purification box 1 and reduce the gap.

[0044] The working principle and use process of the present invention are as follows: when in use, the tail gas processed by phosphorus fluoride flows into the inner side of the spray purification box 1 through the air inlet 2, and the gas is discharged to the outside through the fan 4, so that a negative pressure is formed on the end of the inner side of the spray purification box 1 away from the air inlet 2, so that the tail gas moves along the air flow channel 11, and the walking route of the tail gas is extended by multiple first partitions 6 and second partitions 7. The flow rate of the tail gas can be slowed down by the porous filler 9, and the contact surface area between the alkali solution and the tail gas is increased. The spray head 505 on the lower surface of the spray pipe 504 sprays out the alkali solution to absorb the harmful substances in the tail gas. The alkali solution inside the liquid storage tank 8 can be extracted by the circulation pump group 501 for circulation to improve the absorption effect. The activated carbon plate 13 adsorbs and removes the harmful substances in the tail gas. Furthermore, an electric heating wire 12 is arranged on the inner side of the second partition 7, which can heat the inner side of the spray purification box 1 to increase the reaction temperature. Finally, the purified tail gas flows to the outside through the air inlet 2.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A phosphorus fluoride processing tail gas treatment device, characterized in that: include: A spray purification box (1), wherein an air inlet (2) is provided on one end surface of the spray purification box (1); An air outlet (3) is arranged on the other end surface of the spray purification box (1), and a fan (4) is provided inside the air outlet (3); A first partition (6); A second partition (7) is arranged side by side with the first partition (6) along the long side of the spray purification box (1), and the ends of the second partition (7) and the first partition (6) are staggered to form an air flow channel (11); A supporting mesh plate (10) is fixed between two adjacent first partition plates (6), and a porous filler (9) is provided on the supporting mesh plate (10); The spray assembly is arranged at the top of the inner side of the spray purification box (1) to spray the alkaline solution for absorbing harmful substances in the tail gas from top to bottom.

2. A phosphorus fluoride processing tail gas treatment device according to claim 1, characterized in that: The spray assembly comprises a circulation pump group (501), a liquid extraction pipe (502), a liquid outlet pipe (503), a spray pipe (504) and a spray head (505); the spray pipe (504) is fixed to the top inner side of the spray purification box (1), and the spray head (505) is installed on the lower surface of the spray pipe (504); the circulation pump group (501) is arranged on the upper surface of the spray purification box (1), and one side of the circulation pump group (501) has a liquid outlet pipe (503) connected to the inner side of the spray pipe (504); the liquid extraction pipe (502) is arranged on the front surface of the circulation pump group (501), and one end of the circulation pump group (501) passes through the spray purification box (1) and is connected to a liquid storage tank (8) arranged on the inner side of the spray purification box (1).

3. A phosphorus fluoride processing tail gas treatment device according to claim 2, characterized in that: The spray pipes (504) are evenly distributed at three locations along a short side of the spray purification box (1), and a plurality of spray heads (505) are evenly distributed along the axial direction of each spray pipe (504).

4. A phosphorus fluoride processing tail gas treatment device according to claim 2, characterized in that: The inner wall of the liquid storage tank (8) is provided with a scale line flush with the supporting mesh plate (10).

5. The phosphorus fluoride processing tail gas treatment device according to claim 1, characterized in that: An activated carbon plate (13) is provided on the side wall of the second partition plate (7), and a through hole (14) is provided on the inner side of the activated carbon plate (13).

6. A phosphorus fluoride processing tail gas treatment device according to claim 5, characterized in that: Mounting bolts (15) connected to the second partition plate (7) are arranged at the four inner corners of the activated carbon plate (13).

7. The phosphorus fluoride processing tail gas treatment device according to claim 1, characterized in that: A heating wire (12) is arranged on the inner side of the first partition (6) along its long side.

8. The phosphorus fluoride processing tail gas treatment device according to claim 1, characterized in that: The porous filler (9) is made of bauxite or zeolite.

9. The phosphorus fluoride processing tail gas treatment device according to claim 1, characterized in that: The spray purification box (1) is rectangular, and the number of the first partitions (6) and the number of the second partitions (7) are equal.

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