Boron and phosphorus removal adsorption column for silane preparation

Abstract

A boron and phosphorus removal adsorption column for silane preparation comprises a column body, a central grid cylinder is arranged in the middle of the column body, a plurality of grid partition plates are arranged on the inner wall of the column body from bottom to top, and the column body is divided into three filler layers by the grid partition plates; a cleaning assembly is arranged in the center grid cylinder and used for cleaning the three packing layers. According to the utility model, three layers of fillers are designed, namely the boron adsorption filler, the phosphorus adsorption filler and the chelating resin filler are arranged in sequence, so that boron and phosphorus impurities and residual trace boron and phosphorus impurities in silane gas can be removed step by step in a targeted manner; the cleaning assembly is provided with a plurality of cleaning nozzles, a soft partition plate and a switch valve, and the three packing layers can be accurately cleaned.

Description

Technical Field

[0001] This utility model belongs to the field of silane production technology, and specifically relates to a boron and phosphorus adsorption column for silane preparation. Background Technology

[0002] In the preparation of silane gas, effectively removing impurities such as boron and phosphorus is a crucial step in ensuring product purity. The presence of boron and phosphorus impurities severely affects the quality of silane gas, thereby reducing the performance and quality of downstream products. For example, in semiconductor manufacturing, even trace amounts of boron and phosphorus impurities can lead to unstable electrical performance of chips, affecting chip integration and reliability; in the photovoltaic industry, boron and phosphorus impurities reduce the photoelectric conversion efficiency of solar cells and increase production costs. Therefore, developing efficient boron and phosphorus removal technologies is essential for silane gas preparation.

[0003] Currently, traditional silane gas preparation processes have many limitations in removing boron and phosphorus. Existing adsorption technologies, such as some simple physical adsorption methods, have poor selectivity for boron and phosphorus impurities, making it difficult to deeply remove impurities and meet the high purity requirements of electronic-grade silane gas. While some chemical adsorption methods have relatively good adsorption effects, they suffer from problems such as difficult adsorbent regeneration and short service life, resulting in high production costs.

[0004] The existing boron and phosphorus removal adsorption column structures are also not entirely reasonable. Some adsorption columns have uneven packing distribution, resulting in insufficient contact between the gas and the packing and reducing adsorption efficiency; others lack effective cleaning and regeneration devices, and when the packing becomes saturated, its adsorption performance cannot be restored in time, requiring frequent packing replacement, which not only increases operating costs but also causes resource waste and environmental pollution.

[0005] In summary, there is an urgent need to develop a boron and phosphorus removal adsorption column for silane preparation that features optimized structure, high adsorption efficiency, convenient cleaning and regeneration, and good synergy with the entire preparation system. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a boron and phosphorus adsorption column for silane preparation. This utility model is designed with three layers of packing material, namely boron adsorption packing material, phosphorus adsorption packing material and chelating resin packing material arranged in sequence, which can selectively and stepwise remove boron and phosphorus impurities and residual trace boron and phosphorus impurities in silane gas; the cleaning component is equipped with multiple cleaning nozzles, soft partition plates and switching valves, which can accurately clean the three packing layers respectively.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] A boron and phosphorus adsorption column for silane preparation includes a column body with a central grid tube in the middle. Multiple grid partitions are provided on the inner wall of the column from bottom to top, dividing the column body into three packing layers. A cleaning component is provided inside the central grid tube for cleaning the three packing layers.

[0009] Preferably, the three filler layers, from bottom to top, are boron adsorption filler, phosphorus adsorption filler, and chelating resin filler.

[0010] Preferably, the cleaning assembly includes a main cleaning pipe with a plurality of cleaning nozzles.

[0011] Preferably, the main cleaning pipeline is provided with at least two soft partition plates, which are located at the junction of the two packing layers.

[0012] Preferably, the main cleaning pipeline is equipped with multiple switching valves, which are located at the junction of two packing layers.

[0013] Preferably, the bottom of the main cleaning pipe is provided with a concave positioning groove, which is adapted to the positioning cone. The positioning cone is provided with a through hole and is used to form a passage with the concave positioning groove. The positioning cone is connected to the cleaning fluid inlet pipe.

[0014] Preferably, the cleaning fluid inlet pipe is equipped with a cleaning fluid branch pipe and a purging branch pipe.

[0015] Preferably, the top of the main cleaning pipe is provided with a flange for detachable connection to the top of the column.

[0016] The present invention can achieve the following beneficial effects:

[0017] 1. This invention employs a three-layer packing structure: boron adsorption packing, phosphorus adsorption packing, and chelating resin packing arranged sequentially. This structure effectively and stepwise removes boron and phosphorus impurities, as well as residual trace amounts of boron and phosphorus impurities, from silane gas. The boron adsorption packing utilizes a specific molecular sieve material, exhibiting high selectivity and strong adsorption capacity for boron impurities. The phosphorus adsorption packing employs an iron-aluminum based adsorbent, efficiently adsorbing phosphorus impurities through electrostatic attraction and precipitation. The chelating resin packing further deeply adsorbs residual impurities. This combination significantly improves impurity removal efficiency.

[0018] 2. The cleaning assembly is equipped with multiple cleaning nozzles, flexible partitions, and on / off valves, enabling precise cleaning of the three packing layers separately. By controlling the on / off valves and flexible partitions, cross-contamination between different cleaning steps can be effectively avoided. Furthermore, the cleaning fluid inlet pipe is equipped with cleaning fluid branch pipes and purging branch pipes, which, combined with nitrogen purging, result in excellent cleaning performance, quickly restoring the packing's adsorption properties, extending its service life, and reducing production costs. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0020] Figure 1 This is a schematic diagram of the structure of this utility model;

[0021] Figure 2 for Figure 1 Enlarged view of point A in the middle;

[0022] Figure 3 for Figure 1 Enlarged view of section B in the middle;

[0023] Figure 4 This is a schematic diagram of the cleaning component structure.

[0024] In the diagram: Column 101, central grid cylinder 102, grid partition 103, boron adsorption filler 104, phosphorus adsorption filler 105, chelating resin filler 106, cleaning assembly 107, main cleaning pipe 107.1, cleaning nozzle 107.2, soft partition plate 107.3, switch valve 107.4, concave positioning groove 107.5, positioning cone 108. Detailed Implementation

[0025] Preferred solutions include Figures 1 to 4 As shown, a boron and phosphorus adsorption column for silane preparation includes a column body 101, a central grid cylinder 102 in the middle of the column body 101, and multiple grid partitions 103 arranged from bottom to top on the inner wall of the column body 101. The multiple grid partitions 103 divide the column body 101 into three packing layers, which are boron adsorption packing 104, phosphorus adsorption packing 105 and chelating resin packing 106 from bottom to top.

[0026] Boron adsorption packing materials are selected that do not react with trichlorosilane, such as specific molecular sieve materials. These materials have a porous structure and suitable surface chemistry, enabling them to effectively adsorb boron impurities. Furthermore, they are chemically stable and do not react with trichlorosilane. Acid cleaning desorbs components that form complexes with borate ions from the packing surface, thus cleaning the boron adsorption packing.

[0027] Phosphorus adsorption fillers 105 include iron-aluminum based adsorbents such as activated alumina and ferric oxide. These adsorbents have abundant hydroxyl groups on their surface. Under acidic conditions, these hydroxyl groups protonate, becoming positively charged, and thus attracting negatively charged phosphate ions via electrostatic attraction, achieving phosphorus adsorption. Furthermore, iron and aluminum ions can form insoluble phosphate precipitates with phosphate ions, further enhancing the phosphorus adsorption effect.

[0028] The chelating resin filler 106 coordinates with metal ions such as boron and phosphorus through the branched functional groups, forming a stable structure similar to small molecule chelates, thereby achieving the directional adsorption of boron and phosphorus impurities.

[0029] In this embodiment, three packing layers are set up. The purpose is to first adsorb boron, then adsorb phosphorus, and finally adsorb the remaining boron and phosphorus.

[0030] The central mesh cylinder 102 is equipped with a cleaning component 107, which is used to clean the three packing layers.

[0031] The cleaning assembly 107 includes a main cleaning pipe 107.1, and a plurality of cleaning nozzles 107.2 are provided on the main cleaning pipe 107.1;

[0032] At least two soft partition plates 107.3 are provided on the main cleaning pipe 107.1, and the soft partition plates 107.3 are located at the junction of the two packing layers;

[0033] Multiple on / off valves 107.4 are installed on the main cleaning pipeline 107.1. The on / off valves 107.4 are located at the junction of two packing layers.

[0034] The bottom of the main cleaning pipe 107.1 is provided with a concave positioning groove 107.5, which is adapted to the positioning cone 108. The positioning cone 108 is provided with a through hole and is used to form a passage with the concave positioning groove 107.5; the positioning cone 108 is connected to the cleaning fluid inlet pipe.

[0035] The cleaning fluid inlet pipe is equipped with a cleaning fluid branch pipe and a purging branch pipe.

[0036] The cleaning component 107 in this embodiment can clean the three packing layers separately. The cleaning process is as follows:

[0037] (1) First, an acidic solution is introduced to clean the boron adsorption packing 104. The boron adsorption packing is made of a material that does not react with trichlorosilane, such as a specific molecular sieve material. This type of material has a porous structure and suitable surface chemical properties, which can effectively adsorb boron impurities, and its chemical properties are stable and will not react with trichlorosilane. By cleaning with acid, the components that form complexes with borate ions can be desorbed from the surface of the packing, thus achieving the purpose of cleaning the boron adsorption packing.

[0038] During the cleaning process, the switching valve 107.4 between the boron adsorption packing 104 and the phosphorus adsorption packing 105 is closed.

[0039] (2) Then nitrogen gas is introduced to flush away the residual acidic solution.

[0040] (3) A non-alkaline cleaning agent is then introduced to clean the phosphorus adsorption packing 105. The phosphorus adsorption packing is an iron-aluminum based adsorbent, such as activated alumina or ferric oxide. Under acidic conditions, they adsorb phosphorus through electrostatic attraction and the formation of insoluble phosphate precipitates. Introducing a non-alkaline cleaning agent, such as a specific complexing agent or a neutral buffer solution, can change the charge properties of the packing surface, causing phosphate ions to desorb from the packing surface. At the same time, the non-alkaline cleaning agent can also dissolve some of the iron and aluminum ions that have formed precipitates with phosphate, thereby releasing phosphorus. For example, a certain specific complexing agent can form a stable complex with iron ions, dissolving the iron phosphate precipitate and achieving phosphorus elution.

[0041] During the cleaning process, the switching valve 107.4 between the chelating resin packing 106 and the phosphorus adsorption packing 105 is closed, while the switching valve 107.4 between the boron adsorption packing 104 and the phosphorus adsorption packing 105 is opened.

[0042] (4) Then nitrogen gas is introduced to flush away the residual non-alkaline cleaning agent;

[0043] (5) Finally, open all the switch valves 107.4 to flush the boron adsorption packing 104, phosphorus adsorption packing 105 and chelating resin packing 106 together.

[0044] The above embodiments are merely preferred technical solutions of this utility model and should not be considered as limitations on this utility model. The protection scope of this utility model should be the technical solution described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the protection scope of this utility model.

Claims

1. A boron and phosphorus adsorption column for silane preparation, characterized in that: The column includes a central grid cylinder in the middle, and multiple grid partitions are provided on the inner wall of the column from bottom to top, which divide the column into three packing layers; a cleaning component is provided inside the central grid cylinder, which is used to clean the three packing layers.

2. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The three packing layers, from bottom to top, are boron adsorption packing, phosphorus adsorption packing, and chelating resin packing.

3. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The cleaning assembly includes a main cleaning pipe, which is equipped with several cleaning nozzles.

4. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: At least two soft partition plates are installed on the main cleaning pipeline, and the soft partition plates are located at the junction of the two packing layers.

5. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The main cleaning pipeline is equipped with multiple on / off valves, which are located at the junction of two packing layers.

6. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The bottom of the main cleaning pipe is provided with a concave positioning groove, which is adapted to the positioning cone. The positioning cone is provided with a through hole and is used to form a passage with the concave positioning groove; the positioning cone is connected to the cleaning fluid inlet pipe.

7. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The cleaning fluid inlet pipe is equipped with a cleaning fluid branch pipe and a purging branch pipe.

8. The boron and phosphorus adsorption column for silane preparation according to claim 1, characterized in that: The top of the main cleaning pipe is equipped with a flange for detachable connection to the top of the column.

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