Gas absorption equipment and hydrogen fluoride preparation system

Abstract

The utility model discloses gas absorption equipment which comprises an absorption tower and a Venturi assembly, a spraying assembly, a demister and a cleaning structure which are sequentially arranged in the absorption tower from bottom to top, and the spraying assembly is used for spraying absorption liquid; the absorption tower is provided with a gas inlet, and the gas inlet is located below the Venturi assembly, so that gas entering through the gas inlet flows upwards to the Venturi assembly and is mixed and absorbed with the absorption liquid sprayed by the spraying assembly; the demister is used for removing liquid entrained in the gas; the cleaning structure can spray absorption liquid to the demister to clean the demister. By adopting the gas absorption equipment, gas containing silicon tetrafluoride flows upwards after entering the absorption tower and can be mixed with the absorption liquid sprayed by the spraying assembly in the process of passing through the Venturi assembly, and then part of unabsorbed gas is continuously absorbed by the absorption liquid sprayed by the spraying assembly in the process of flowing towards the spraying assembly, so that the absorption efficiency is improved. And the absorption efficiency of silicon tetrafluoride can be effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of gas treatment equipment, and particularly relates to a gas absorption equipment and a hydrogen fluoride preparation system. BACKGROUND

[0002] In the hydrogen fluoride preparation process, part of fluorine will escape in the form of silicon tetrafluoride gas. If the silicon tetrafluoride gas is treated as waste gas, the conversion rate of hydrogen fluoride will be low, and the equipment cost for treating the waste gas will be increased. Therefore, at present, the silicon tetrafluoride gas is generally absorbed and reused.

[0003] The absorption method of the silicon tetrafluoride gas includes a chemical absorption method, an adsorbent method and a combustion method. For the chemical absorption method, the chemical absorption method generally utilizes a gas absorption tower, silicon tetrafluoride gas and water are introduced into the gas absorption tower, and the two react to generate fluorosilicic acid and silicon dioxide. The absorption efficiency of the existing gas absorption tower is low. CONTENT OF THE INVENTION

[0004] The technical problem to be solved by the application is that the absorption efficiency of the existing gas absorption tower for silicon tetrafluoride in the gas is low, in order to solve the technical problem, a gas absorption equipment with high absorption efficiency and a hydrogen fluoride preparation system are provided.

[0005] The technical scheme provided by the application is:

[0006] A gas absorption equipment comprises:

[0007] An absorption tower, wherein a Venturi assembly, a spraying assembly, a demister and a cleaning structure are arranged in the absorption tower from bottom to top, the spraying assembly is used for spraying absorption liquid;

[0008] The absorption tower is also provided with an air inlet, the air inlet is located below the Venturi assembly, so that the gas entering through the air inlet flows upward to the Venturi assembly and is mixed and absorbed with the absorption liquid sprayed by the spraying assembly;

[0009] The demister is used for removing liquid entrained in the gas, and the cleaning structure can spray the absorption liquid toward the demister to clean the demister.

[0010] The gas absorption equipment has the advantages that the gas containing silicon tetrafluoride flows upwards in the absorption tower, and can be mixed with the absorption liquid sprayed by the spraying assembly in the process of passing through the Venturi assembly, so that the absorption is more sufficient, and then the part of the gas not absorbed continues to be absorbed by the absorption liquid sprayed by the spraying assembly in the process of flowing towards the spraying assembly. The remaining gas is discharged from the absorption tower after passing through the demister and the cleaning structure. At the same time, the substances remaining in the demister can be cleaned by spraying the absorption liquid through the cleaning structure, and the cleaned liquid falls to the bottom of the absorption tower to realize the absorption and utilization of silicon tetrafluoride. In this way, the absorption efficiency of silicon tetrafluoride can be effectively improved.

[0011] Further, the absorption tower is also provided with a circulating port for the liquid at the bottom of the absorption tower to pass through;

[0012] The gas absorption equipment further comprises a circulating pump, and the circulating port and the spraying assembly are communicated through the circulating pump, so that the liquid at the bottom of the absorption tower is circulated to the spraying assembly.

[0013] Further, the Venturi assembly comprises at least two layers of rod grid layers arranged in a vertical direction, each of the rod grid layers comprises a plurality of Venturi rods arranged in a horizontal direction, so as to form through ports between adjacent two Venturi rods;

[0014] The through ports in any adjacent two layers of the rod grid layers are staggered in the vertical direction.

[0015] Further, the gas absorption equipment further comprises a liquid inlet assembly, and the liquid inlet assembly is connected with the spraying assembly and the cleaning structure.

[0016] Further, the absorption tower is also provided with a liquid supplement port, and the liquid supplement port is communicated with the liquid inlet assembly.

[0017] Further, the spraying assembly comprises a plurality of layers of spraying pipes, and the plurality of layers of spraying pipes are arranged in a vertical direction.

[0018] Further, the gas absorption equipment further comprises a stirring structure, and the stirring structure is arranged in the absorption tower and located at the bottom of the absorption tower, and is used for stirring the liquid at the bottom of the absorption tower.

[0019] Further, the absorption tower is also provided with a sampling port and a discharge port, and the sampling port and the discharge port are located on the side wall of the absorption tower, and the sampling port is located above the discharge port.

[0020] Further, the absorption tower is also provided with an exhaust port, and the exhaust port is located at the top of the absorption tower.

[0021] A hydrogen fluoride preparation system comprises the gas absorption equipment as described above. Attached Figure Description

[0022] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0023] Figure 1 This is a schematic diagram of the structure of a gas absorption device provided in an embodiment of this application.

[0024] Label Explanation:

[0025] 110. Absorption tower; 111. Air inlet; 112. Circulation port; 113. Outlet; 114. Drain port; 115. Exhaust port; 116. Liquid replenishment port; 120. Stirring structure; 130. Venturi assembly; 140. Spray assembly; 150. Demister; 160. Cleaning structure; 170. Spray valve. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the equipment 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 application.

[0028] On one hand, this application provides a gas absorption device for absorbing silicon tetrafluoride gas during the preparation of hydrogen fluoride. For example... Figure 1 As shown, the gas absorption device includes an absorption tower 110 and, from bottom to top, a Venturi assembly 130, a spray assembly 140, a demister 150, and a cleaning structure 160 arranged in sequence within the absorption tower 110.

[0029] The absorption tower 110 is provided with an air inlet 111 below the venturi assembly 130, for feeding the gas containing silicon tetrafluoride into the absorption tower 110, so that the gas entering through the air inlet 111 flows upward. The spraying assembly 140 is used to spray the absorption liquid, so that when the gas flows to the venturi assembly 130, it is mixed and absorbed with the absorption liquid sprayed by the spraying assembly 140, so as to improve the absorption efficiency of the absorption liquid to silicon tetrafluoride; the demister 150 is used to separate the gas and liquid to remove the liquid entrained in the gas, thereby improving the absorption efficiency of silicon tetrafluoride; the cleaning structure 160 can spray the absorption liquid toward the demister 150 to clean the demister 150, so as to avoid the demister 150 being blocked, and at the same time improve the absorption efficiency of silicon tetrafluoride.

[0030] It should be noted that in the embodiment, the absorption liquid is a 30% concentration of fluorosilicic acid solution, and fluorosilicic acid and silicon dioxide will be generated during the absorption process, so that the demister 150 may be blocked after a long time of use. At this time, the cleaning structure 160 can spray the absorption liquid toward the demister 150 to clean the residues on the demister 150 and drop them to the bottom of the absorption tower 110.

[0031] By using the above-mentioned gas absorption equipment, the gas containing silicon tetrafluoride enters the absorption tower 110 and flows upward, and during the process of passing through the venturi assembly 130, the gas can be mixed with the absorption liquid sprayed by the spraying assembly 140 to achieve more complete absorption, and then part of the gas not absorbed flows toward the spraying assembly 140, and the gas is continuously absorbed by the absorption liquid sprayed by the spraying assembly 140. The remaining gas passes through the demister 150 and the cleaning structure 160 and is discharged from the absorption tower 110. At the same time, the substances remaining on the demister 150 can be cleaned by spraying the absorption liquid through the cleaning structure 160, and the cleaned liquid drops to the bottom of the absorption tower 110, realizing the absorption and utilization of silicon tetrafluoride. In this way, the absorption efficiency of silicon tetrafluoride can be effectively improved.

[0032] It can be understood that the cleaning structure 160 can also clean the spraying assembly 140 below and the inner wall of the absorption tower 110, and the residues on the spraying assembly 140 and the inner wall of the absorption tower 110 can be cleaned and dropped to the bottom of the absorption tower 110.

[0033] In one embodiment, the absorption tower 110 is also provided with a circulation port 112 for the liquid at the bottom of the absorption tower 110 to pass through; the gas absorption equipment further comprises a circulating pump, and the circulation port 112 and the spraying assembly 140 are communicated through the circulating pump, so that the liquid at the bottom of the absorption tower 110 is circulated to the spraying assembly 140, realizing the reuse of the absorption liquid, improving the utilization rate, and reducing the cost.

[0034] In one embodiment, the absorption tower 110 also has a sampling outlet 113 and a discharge outlet 114, both located on the side wall of the absorption tower 110, with the sampling outlet 113 positioned above the discharge outlet 114. The sampling outlet 113 is used to discharge the liquid after absorption, and a sampling pump can be installed to collect the liquid. The discharge outlet 114 is preferably flush with the bottom of the absorption tower 110, or the bottom wall of the absorption tower 110 can be sloped, with the discharge outlet 114 located at the lower end of the bottom wall, to ensure that any remaining substances in the absorption tower 110 are discharged. It is understood that control valves are provided at both the sampling outlet 113 and the discharge outlet 114.

[0035] In one embodiment, the absorption tower 110 is further provided with an exhaust port 115, which is located at the top of the absorption tower 110 and is connected to a gas processing device to discharge the absorbed gas from the absorption tower 110. It should be noted that, in this embodiment, experimental verification shows that using a 30% concentration fluorosilicic acid solution for absorption can achieve an absorption efficiency of 98% for silicon tetrafluoride.

[0036] In one embodiment, the gas absorption device further includes a stirring structure 120, which is disposed inside the absorption tower 110 and located at the bottom of the absorption tower 110, that is, below the gas inlet 111. The stirring structure 120 is used to stir the liquid at the bottom of the absorption tower 110 to prevent excessive sedimentation due to stagnation, thus facilitating the collection of the liquid.

[0037] In one embodiment, the stirring structure 120 includes a stirring drive and stirring blades. The stirring drive is disposed in the absorption tower 110 and connected to the stirring blades. The stirring blades are located at the bottom of the absorption tower 110 and are used to stir the liquid at the bottom of the absorption tower 110 during rotation to prevent the liquid from precipitating due to stillness.

[0038] In one embodiment, the gas absorption device further includes a liquid inlet assembly connected to the spray assembly 140 and the cleaning structure 160, for introducing absorbent liquid into the spray assembly 140 and the cleaning structure 160. Furthermore, the absorption tower 110 also has a replenishment port 116, with the liquid inlet assembly connected to the replenishment port 116 to replenish absorbent liquid to the bottom of the absorption tower 110 through the replenishment port 116.

[0039] It should be noted that, in the initial stage, the absorption liquid sprayed by the spraying assembly 140 can be provided only through the liquid inlet assembly; after a certain amount of absorption liquid is accumulated at the bottom of the absorption tower 110, the absorption liquid at the bottom can be pumped to the spraying assembly 140 by a circulating pump, at which time the liquid supply of the liquid inlet assembly can be stopped to save the liquid consumption; after a period of operation, the amount of silicon tetrafluoride absorbed in the absorption liquid increases, in order to avoid a significant reduction in absorption efficiency, the absorption liquid can be quickly supplemented into the absorption tower 110 through the liquid supplement port 116; of course, it can also be supplemented through the spraying assembly 140, which is not limited herein. Specifically to Figure 1 In the embodiment shown, the liquid supplement port 116 is located below the gas inlet port 111.

[0040] In one embodiment, the Venturi assembly 130 includes at least two layers of rod grid layers arranged in a vertical direction, each rod grid layer including a plurality of Venturi rods arranged in a horizontal direction to form through openings between any two adjacent Venturi rods; the through openings in any two adjacent rod grid layers are staggered in the vertical direction. Specifically, in the embodiment, the Venturi assembly 130 is a rod layer, and the gas flows through the rod layer to form strong gas-liquid turbulent contact with the absorption liquid. Moreover, the rod layer can break the liquid droplets, increase the specific surface area of the absorption liquid, and improve the mass transfer efficiency between the gas and liquid phases, thereby improving the absorption efficiency of silicon tetrafluoride.

[0041] In one embodiment, the spraying assembly 140 includes a plurality of spraying pipes arranged in a vertical direction to improve the uniformity and density of the distribution of the absorption liquid, ensure that the absorption liquid can be in full contact with the gas, and improve the absorption efficiency of silicon tetrafluoride.

[0042] Further, the gas absorption device further includes a plurality of spraying valves 170, each spraying valve 170 being connected to a corresponding spraying pipe, and the opening and closing of the corresponding spraying pipe can be controlled through the spraying valve 170. In this way, the number of spraying pipes that are opened can be controlled according to the gas flow; at the same time, a spraying pipe that has a problem can be closed individually without the need to close all the spraying pipes.

[0043] On the other hand, the present application also provides a hydrogen fluoride preparation system, which includes the gas absorption device in the above-mentioned embodiments to absorb and reuse the escaped silicon tetrafluoride gas in the hydrogen fluoride preparation process.

[0044] In summary, the gas absorption device and the hydrogen fluoride preparation system provided by the present application have at least the following advantages:

[0045] 1. By arranging the Venturi assembly 130 and the spraying assembly 140 in the absorption tower 110, the absorption efficiency of the absorption liquid for the silicon tetrafluoride gas can be improved;

[0046] 2. The cleaning structure 160 is arranged above the mist eliminator 150 to clean the mist eliminator 150, which can avoid the clogging of the mist eliminator 150 and can also bring the liquid remaining on the mist eliminator 150 to the bottom of the absorption tower 110, further improving the absorption efficiency of the silicon tetrafluoride gas.

[0047] While the embodiments of the present application have been shown and described, it is to be understood that the embodiments can be varied, modified, substituted and changed by those skilled in the art without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A gas absorption device, characterized in that, include: An absorption tower, wherein a Venturi assembly, a spray assembly, a demister and a cleaning structure are arranged from bottom to top inside the absorption tower, and the spray assembly is used to spray the absorbent liquid. The absorption tower is also provided with an air inlet, which is located below the Venturi assembly, so that the gas entering through the air inlet flows upward to the Venturi assembly and mixes with the absorbent sprayed by the spray assembly for absorption. The demister is used to remove liquid entrained in the gas; the cleaning structure is capable of spraying the absorbent liquid onto the demister to clean it.

2. The gas absorption device according to claim 1, characterized in that, The absorption tower is also provided with a circulation port for the liquid at the bottom of the absorption tower to pass through; The gas absorption device also includes a circulation pump, and the circulation port and the spray assembly are connected through the circulation pump so that the liquid at the bottom of the absorption tower is circulated to the spray assembly.

3. The gas absorption device according to claim 1, characterized in that, The Venturi assembly includes at least two bar grid layers spaced apart in a vertical direction, each bar grid layer including a plurality of Venturi bars spaced apart in a horizontal direction to form a through opening between two adjacent Venturi bars. The through-holes in any two adjacent bar grid layers are staggered in the vertical direction.

4. The gas absorption device according to claim 1, characterized in that, It also includes a liquid inlet assembly, which is connected to the spray assembly and the cleaning structure.

5. The gas absorption device according to claim 4, characterized in that, The absorption tower is also provided with a liquid replenishment port, which is connected to the liquid inlet assembly.

6. The gas absorption device according to claim 1, characterized in that, The spray assembly includes multiple layers of spray pipes, which are arranged at intervals along the vertical direction.

7. The gas absorption device according to claim 1, characterized in that, It also includes a stirring structure, which is disposed inside the absorption tower and located at the bottom of the absorption tower, for stirring the liquid at the bottom of the absorption tower.

8. The gas absorption device according to claim 1, characterized in that, The absorption tower is also provided with a sampling outlet and a discharge outlet. Both the sampling outlet and the discharge outlet are located on the side wall of the absorption tower, and the sampling outlet is located above the discharge outlet.

9. The gas absorption device according to claim 1, characterized in that, The absorption tower is also provided with an exhaust port, which is located at the top of the absorption tower.

10. A hydrogen fluoride preparation system, characterized in that, Includes the gas absorption device according to any one of claims 1-9.

Images