Tail gas treatment adsorption column
By setting a rotating, staggered heat-conducting grid and heat exchange tube structure inside the adsorption column, the problem of low heat exchange efficiency in polysilicon production tail gas treatment is solved, achieving more efficient tail gas purification and adsorbent regeneration, reducing costs and extending equipment life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU RICH TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-05-15
AI Technical Summary
In existing polysilicon production tail gas treatment, the heat exchange efficiency of the heat exchange tubes in the adsorption column is low, resulting in high adsorbent regeneration costs and serious resource waste.
It adopts a combination structure of heat-conducting grid and heat exchange tube. The heat-conducting grid is made of metal, and the adjacent two layers are rotated and staggered to increase the heat conduction area and heat transfer uniformity. Combined with spiral heat exchange half tube and reinforcing tube, it can improve heat transfer efficiency.
It achieves more efficient exhaust gas purification, reduces manufacturing costs, extends equipment lifespan, and improves adsorbent regeneration efficiency.
Smart Images
Figure CN224236454U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of exhaust gas treatment technology, and specifically to an exhaust gas treatment adsorption column. Background Technology
[0002] In polysilicon production, the trichlorosilane synthesis and reduction processes generate a large amount of tail gas. It is estimated that for every 1 kg of polysilicon produced, 40 kg of tail gas is generated. Its main components are hydrogen (H2), hydrogen chloride (HCl), dichlorosilane (SiH2Cl2), trichlorosilane (SiHCl3), and silicon tetrachloride (SiCl4). Polysilicon tail gas is both a valuable raw material or intermediate product and a substance that poses a significant threat to the environment. Simply treating it before discharge would result in large amounts of waste liquid and gas, causing substantial resource waste. Therefore, effectively separating and recovering these components to turn waste into valuable resources is a crucial problem that polysilicon production must solve.
[0003] In the tail gas recovery system of polysilicon plants, the adsorption column is a crucial piece of equipment used to absorb residual HCl and chlorosilanes in hydrogen gas, thereby obtaining high-purity hydrogen. After adsorption, the adsorbent in the column needs to be regenerated to reduce costs, and this regeneration requires heating. Current technology typically involves installing heat exchange tubes inside the adsorption column, through which a heat source is passed to heat the adsorbent. However, due to the limited contact area between the heat exchange tubes and the tail gas within the adsorption column, the heat exchange efficiency is relatively low.
[0004] Therefore, existing technologies need to be improved. Utility Model Content
[0005] The technical problem to be solved by this utility model is that the heat exchange efficiency of the heat exchange tube in the adsorption column of the prior art is low. The purpose is to provide an adsorption column for exhaust gas treatment, which adopts corresponding technical means and has the beneficial effects of larger heat conduction area, higher heat exchange efficiency, lower manufacturing cost, and reliability and durability.
[0006] This utility model is achieved through the following technical solution:
[0007] An exhaust gas treatment adsorption column includes an adsorption column body, the interior of which is provided with a heat-conducting grid and a heat exchange tube. The heat exchange tube passes through the heat-conducting grid and is connected to the heat-conducting grid. The heat-conducting grids of adjacent layers are rotated and staggered. The adsorption column body is provided with a product gas inlet and a product gas outlet, which are located at opposite ends of the heat-conducting grid.
[0008] In the above technical solution, multiple heat exchange tubes are vertically installed inside the adsorption column, and multiple layers of heat-conducting grids are horizontally installed. The heat exchange tubes pass through the through-holes of the heat-conducting grids, and the outer wall of the heat exchange tubes abuts against the inner wall of the heat-conducting grids to achieve better heat conduction. Since the heat-conducting grids are made of a metal material with fast thermal conductivity, it is easier for the heat exchange tubes to transfer heat to the heat-conducting grids. Furthermore, the contact area between the heat-conducting grids and the exhaust gas is larger than that between the heat exchange tubes and the exhaust gas, resulting in a larger heat conduction area, faster exhaust gas heating, and faster heating of the adsorbent, achieving a better exhaust gas purification effect. At the same time, the adjacent upper and lower layers of heat-conducting grids are rotated and misaligned, that is, the lower layer of heat-conducting grids rotates around the center at a certain angle relative to the upper layer of heat-conducting grids, causing the through-holes of the upper and lower layers of heat-conducting grids to be misaligned. This makes the exhaust gas flow from bottom to top turbulent, resulting in more uniform mixing, which is beneficial to heat conduction.
[0009] Furthermore, in this invention, the outer wall of the adsorption column body is provided with a spiral heat exchange half-tube, the heat exchange half-tube having a tube inlet and a tube outlet, the tube inlet being located below the tube outlet.
[0010] Furthermore, in this utility model, a reinforcing tube is provided on the outside of the heat exchange tube, one end of the heat exchange tube passes through the adsorption column body, and the reinforcing tube is connected to the adsorption column body at the point of passage.
[0011] Furthermore, in this invention, the end face of the reinforcing tube is connected to the outer wall of the heat exchange tube, and a gap is left between the reinforcing tube and the heat exchange tube.
[0012] Furthermore, in this invention, the top of the adsorption column body is provided with an adsorbent filling port, the bottom of the adsorption column body is provided with an adsorbent discharge port, and the product gas inlet and the product gas outlet are located at the bottom and top of the adsorption column body, respectively.
[0013] Furthermore, in this invention, the bottom surface of the adsorption column body is concave, and a drain port is provided at the center of the bottom surface of the adsorption column body.
[0014] Furthermore, in this invention, the adsorption column body is provided with a temperature and pressure detection mechanism for detecting the internal ambient temperature and pressure.
[0015] Furthermore, in this invention, the temperature and pressure detection mechanism includes a thermometer and a pressure gauge, which are connected to the adsorption column body.
[0016] Furthermore, in this invention, the sidewall of the adsorption column body is provided with symmetrical lifting lugs.
[0017] Furthermore, in this invention, a supporting skirt is provided at the bottom of the adsorption column body.
[0018] Compared with the prior art, this utility model has the following advantages and beneficial effects:
[0019] 1. Large heat conduction area: The adsorption column body has multiple heat exchange tubes installed vertically inside and multiple layers of heat conduction grids installed horizontally. The heat exchange tubes pass through the through holes of the heat conduction grids, and the outer wall of the heat exchange tubes abuts against the inner wall of the heat conduction grids. Since the heat conduction grids are made of metal material with fast thermal conductivity, it is easier to transfer heat to the heat conduction grids by abutting the heat exchange tubes. In addition, the contact area between the heat conduction grids and the exhaust gas is larger than that between the heat exchange tubes and the exhaust gas. As a result, the heat conduction area is larger, the exhaust gas heats up faster, and the adsorbent is heated faster, achieving a better exhaust gas purification effect.
[0020] 2. Uniform heat transfer: The adjacent upper and lower heat conduction grids are rotated and misaligned, that is, the lower heat conduction grid rotates around the center at a certain angle relative to the upper heat conduction grid, so that the through holes of the upper and lower heat conduction grids are not aligned. This causes a certain degree of turbulence when the exhaust gas flows from bottom to top, making the exhaust gas mix more evenly, which is conducive to uniformly heating all the adsorbents inside the adsorption column. Attached Figure Description
[0021] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present invention and form part of this application, do not constitute a limitation thereof. In the drawings:
[0022] Figure 1 This is a schematic diagram of the internal structure of an adsorption column for exhaust gas treatment according to the present invention.
[0023] Figure 2 This is a schematic diagram of the structure of the heat-conducting grid and heat exchange tube of this utility model.
[0024] The attached diagram shows the markings and corresponding component names: 1-Adsorbent discharge port, 2-Thermometer, 3-Heat exchange half-pipe, 4-Heat exchange tube, 5-Pipe outlet, 6-Lifting lug, 7-Adsorbent filling port, 8-Product gas outlet, 9-Heat-conducting grid, 10-Pressure gauge, 11-Pipe inlet, 12-Adsorption column body, 13-Product gas inlet, 14-Reinforcing tube, 15-Drain port, 16-Support skirt. Detailed Implementation
[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.
[0026] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the use of terms such as "horizontal" or "vertical" does not imply that the component must be absolutely horizontal or vertical, but rather that it can be slightly tilted. For example, "horizontal" merely means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted. In the description of the embodiments of this utility model, "a plurality of" means at least two.
[0027] In the description of the embodiments of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0028] Example
[0029] This embodiment provides an adsorption column for exhaust gas treatment, such as... Figures 1-2 As shown, the specific structure is described below.
[0030] Combination Figure 1 As shown, the exhaust gas treatment adsorption column in this embodiment mainly consists of four parts: adsorption column body 12, heat exchange half tube 3, heat conduction grid 9, and heat exchange tube 4.
[0031] Furthermore, in combination Figure 1 As shown, the adsorption column body 12 is in the shape of a tower tank and is placed vertically. A support skirt 16 raised off the ground is installed at the bottom of the adsorption column body 12. The adsorption column body 12 is filled with adsorbent (such as activated carbon, molecular sieve, activated alumina, silica gel, etc.) and exhaust gas.
[0032] Combination Figure 1As shown, the heat exchange tube 4 is vertically installed inside the adsorption column body 12, passing through a bottom hole on the bottom surface of the adsorption column body 12. The reinforcing tube 14 is in the form of a sleeve, fitted over the heat exchange tube 4. The bottom of the reinforcing tube 14 has an end face, through which the heat exchange tube 4 passes and is fixedly connected. The outer wall of the reinforcing tube 14 is welded to the wall of the bottom hole. The bottom end of the reinforcing tube 14 extends from the bottom hole of the adsorption column body 12, and a gap is left between the reinforcing tube 14 and the heat exchange tube 4. The reinforcing tube 14 prevents direct contact between the adsorption column body 12 and the heat exchange tube 4, reducing the temperature difference between the upper and lower parts of the heat exchange tube 4 at the bottom hole, significantly reducing the thermal stress caused by the temperature difference between the adsorption column body 12 and the heat exchange tube 4, and improving the safety and service life of the exhaust gas treatment adsorption column.
[0033] The heat exchanger 4 transports a fluid carrying a heat source, which releases heat within the adsorption column body 12. The heat is then conducted to the heat-conducting gas (the filling exhaust gas) and then transferred to the adsorbent, promoting adsorbent regeneration.
[0034] It should be noted that, as Figure 1 As shown, the heat exchange tube 4 can be configured with four, six, twelve, or eighteen tubes.
[0035] In some implementations of this embodiment, combined with Figure 1 and Figure 2 As shown, the heat-conducting grid 9 is composed of crisscrossing metal strips, or it can be made from a metal plate with several through holes machined into it. The heat-conducting grid 9 is horizontally installed inside the adsorption column body 12, and multiple layers are installed from top to bottom, for example, twenty layers, with a spacing of 30 or 40 centimeters between adjacent layers. At the same time, the adjacent upper and lower layers of heat-conducting grid 9 are rotated and misaligned, that is, the lower layer of heat-conducting grid 9 is rotated at a certain angle, such as 30 degrees, relative to the upper layer of heat-conducting grid 9 around the center line of the adsorption column body 12, so that the through holes of the upper and lower layers of heat-conducting grid 9 are misaligned, which makes the exhaust gas inside flow turbulent from bottom to top, mixes more evenly, and is conducive to heat conduction.
[0036] It should be noted that both the heat exchange tube 4 and the heat-conducting grid 9 can be made of a metal material that conducts heat easily, such as carbon steel or copper alloy steel, with an anti-corrosion treatment on the surface. The heat exchange tube 4 passes through the through-hole of the heat-conducting grid 9, and the wall of the through-hole of the heat-conducting grid 9 abuts against the outer wall of the heat exchange tube 4 to achieve heat conduction. The through-hole of the heat-conducting grid 9 can be a circular hole with the same cross-sectional area as the heat exchange tube 4, resulting in a larger contact area. Alternatively, vertically aligned through-holes can be machined on the heat-conducting grid 9, allowing only the heat exchange tube 4 to pass through, while the other through-holes are not aligned.
[0037] In some embodiments of this example, the temperature and pressure detection mechanism includes a thermometer 2 and a pressure gauge 10, used to detect the temperature and pressure inside the adsorption column body 12. The thermometer 2 is fixedly installed on the left outer wall of the adsorption column body 12, and the temperature monitoring probe extends into the interior of the adsorption column body 12. The pressure gauge 10 is installed on the right outer wall of the adsorption column body 12, and the probe of the pressure gauge 10 extends into the interior of the adsorption column body 12. Through the thermometer 2 and the pressure gauge 10, the reaction temperature and pressure inside the adsorption column body 12 can be known, facilitating control.
[0038] In some embodiments of this example, the heat exchange half-tube 3 is spirally arranged around the outer wall of the adsorption column body 12. The heat exchange half-tube 3 has a tube inlet 11 and a tube outlet 5. The tube inlet 11 is located below the tube outlet 5. A fluid with a heat source or a cold source is introduced from the tube inlet 11, and the fluid heats the internal environment of the adsorption column body 12.
[0039] In some embodiments of this example, the top of the adsorption column body 12 is provided with an adsorbent filling port 7 and a product gas outlet 8. Adsorbent is added through the adsorbent filling port 7, and purified hydrogen is collected through the product gas outlet 8. The bottom of the adsorption column body 12 is provided with an adsorbent discharge port 1 and a product gas inlet 13. The adsorbent discharge port 1 is used to pour out the used adsorbent for easy replacement. The product gas inlet 13 is connected to the tail gas conveying pipeline, which can send the tail gas to be purified into the interior of the adsorption column body 12. The bottom of the adsorption column body 12 is a concave surface with a drain port 15 located at the lowest point of the concave surface, which facilitates the discharge of residual adsorbent and other impurities. Valves are installed at the drain port 15, the product gas inlet 13, and the product gas outlet 8.
[0040] Furthermore, a lifting lug 6 is installed on each of the left and right sides of the adsorption column body 12, which facilitates the movement of the adsorption column body 12.
[0041] The working principle of the exhaust gas treatment adsorption column in this embodiment is as follows:
[0042] The exhaust gas to be purified is sent into the adsorption column body 12 through the product gas inlet 13, and the fluid is sent into the heat exchange half-pipe 3 and heat exchange tube 4. The fluid is transported from bottom to top in the heat exchange half-pipe 3 and heat exchange tube 4. The fluid exchanges heat with the exhaust gas through the wall of the adsorption column body 12, the surface of the heat exchange tube 4, and the surface of the heat-conducting grid 9. The exhaust gas then transfers heat to the adsorbent, thereby heating the adsorbent. The exhaust gas flows from bottom to top. After the exhaust gas is adsorbed, the hydrogen is recovered through the product gas outlet 8. During the regeneration of the adsorbent, it needs to be heated first and then cooled. The temperature of the adsorbent after heating must reach the regeneration temperature, and the temperature of the adsorbent after cooling is at room temperature or below room temperature. During regeneration, the harmful gases discharged by the adsorbent are recovered by backflushing. During adsorption, the exhaust gas enters the adsorption column body 12, the harmful substances are adsorbed by the adsorbent, the hydrogen rises and is recovered and discharged through the product gas outlet 8. The hydrogen is collected and used for the production of polycrystalline silicon.
[0043] Compared to traditional heat exchangers using bare tubes, the exhaust gas treatment adsorption column of this invention has a larger heat exchange area. Existing technologies also involve welding heat dissipation fins to bare tubes to increase the heat dissipation area, but direct welding to the bare tube can easily lead to stress concentration and damage at the welding points. In this embodiment, the heat-conducting grid 9 does not need to be welded to the heat exchange tube 4, significantly improving the stability and durability of the heat exchange tube 4 compared to finned bare tubes, thereby greatly extending its service life. Furthermore, by eliminating welding stress and thermal stress, the thickness of the heat exchange tube 4 can be reduced, lowering its procurement cost and thus significantly reducing the manufacturing cost of the exhaust gas treatment adsorption column.
[0044] In summary, the exhaust gas treatment adsorption column of this utility model includes an adsorption column body 12. The adsorption column body 12 has a heat-conducting grid 9 and a heat exchange tube 4 inside. The heat exchange tube 4 passes through and connects to the heat-conducting grid 9. Adjacent heat-conducting grids 9 are rotated and staggered. The adsorption column body 12 has a product gas inlet 13 and a product gas outlet 8, located at opposite ends of the heat-conducting grid 9. A spiral heat exchange half-tube 3 is provided on the outer wall of the adsorption column body 12. The heat exchange half-tube 3 has a tube inlet 11 and a tube outlet 5, with the tube inlet 11 located below the tube outlet 5. A reinforcing tube 14 is sleeved around the heat exchange tube 4. One end of the heat exchange tube 4 passes through the adsorption column body 12, and the reinforcing tube 14 connects to the adsorption column body 12 at the point of penetration. The end face of the reinforcing tube 14 connects to the outer wall of the heat exchange tube 4, and a gap is left between the reinforcing tube 14 and the heat exchange tube 4. The top of the adsorption column body 12 is provided with an adsorbent filling port 7, and the bottom of the adsorption column body 12 is provided with an adsorbent discharge port 1. The product gas inlet 13 and the product gas outlet 8 are located at the bottom and top of the adsorption column body 12, respectively. The bottom surface of the adsorption column body 12 is concave, and a drain port 15 is provided at the center of the bottom surface of the adsorption column body 12. The adsorption column body 12 is provided with a temperature and pressure detection mechanism for detecting the internal ambient temperature and pressure. The temperature and pressure detection mechanism includes a thermometer 2 and a pressure gauge 10, which are connected to the adsorption column body 12. Symmetrical lifting lugs 6 are provided on the side walls of the adsorption column body 12. A support skirt 16 is provided at the bottom of the adsorption column body 12. Therefore, the exhaust gas treatment adsorption column of this embodiment has the beneficial effects of a larger heat conduction area and higher heat exchange efficiency.
[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.
Claims
1. A tail gas treatment adsorption column, characterized in that, The adsorption column body (12) includes a heat-conducting grid (9) and a heat exchange tube (4) inside the adsorption column body (12). The heat exchange tube (4) passes through the heat-conducting grid (9) and is connected to the heat-conducting grid (9). The heat-conducting grids (9) of adjacent layers are rotated and staggered. The adsorption column body (12) is provided with a product gas inlet (13) and a product gas outlet (8). The product gas inlet (13) and the product gas outlet (8) are located at the two ends of the heat-conducting grid (9), respectively.
2. The exhaust gas treatment adsorption column according to claim 1, characterized in that, The outer wall of the adsorption column body (12) is provided with a spiral heat exchange half tube (3), the heat exchange half tube (3) has a tube inlet (11) and a tube outlet (5), the tube inlet (11) is located below the tube outlet (5).
3. The exhaust gas treatment adsorption column according to claim 1, characterized in that, The heat exchange tube (4) is fitted with a reinforcing tube (14) on its outside. One end of the heat exchange tube (4) passes through the adsorption column body (12), and the reinforcing tube (14) is connected to the adsorption column body (12) at the point of passage.
4. The exhaust gas treatment adsorption column according to claim 3, characterized in that, The end face of the reinforcing tube (14) is connected to the outer wall of the heat exchange tube (4), and there is a gap between the reinforcing tube (14) and the heat exchange tube (4).
5. The exhaust gas treatment adsorption column according to claim 1, characterized in that, The top of the adsorption column body (12) is provided with an adsorbent filling port (7), the bottom of the adsorption column body (12) is provided with an adsorbent discharge port (1), and the product gas inlet (13) and the product gas outlet (8) are located at the bottom and top of the adsorption column body (12), respectively.
6. The exhaust gas treatment adsorption column according to claim 5, characterized in that, The bottom surface of the adsorption column body (12) is concave, and a drain port (15) is provided at the center of the bottom surface of the adsorption column body (12).
7. The exhaust gas treatment adsorption column according to claim 1, characterized in that, The adsorption column body (12) is equipped with a temperature and pressure detection mechanism for detecting the internal environment temperature and pressure.
8. The exhaust gas treatment adsorption column according to claim 7, characterized in that, The temperature and pressure detection mechanism includes a thermometer (2) and a pressure gauge (10), which are connected to the adsorption column body (12).
9. The exhaust gas treatment adsorption column according to any one of claims 1-8, characterized in that, The sidewalls of the adsorption column body (12) are provided with symmetrical lifting lugs (6).
10. The exhaust gas treatment adsorption column according to any one of claims 1-8, characterized in that, The bottom of the adsorption column body (12) is provided with a support skirt (16).