A gradient pressure reactor for supercritical purification of quartz sand

Abstract

This invention discloses a gradient pressure reactor for purifying quartz sand using supercritical fluid extraction. It includes a high-pressure cylinder, a medium-pressure cylinder, and a low-pressure cylinder separated along the axial direction, as well as a supercritical fluid injection system, a gradient pressure control system, and a control box. Heating jackets are installed on the outer walls of the high-pressure, medium-pressure, and low-pressure cylinders. A feed pipe is installed on the high-pressure cylinder, and a discharge pipe is installed at the bottom of the low-pressure cylinder. On / off valves are installed between adjacent feed pipes, high-pressure cylinders, medium-pressure cylinders, low-pressure cylinders, and discharge pipes. The gradient pressure control system includes a booster pump for the high-pressure cylinder, a pressure regulating valve for the medium-pressure cylinder, and a back pressure valve for the low-pressure cylinder. This invention utilizes a high-pressure cylinder for dissolving metallic impurities, a medium-pressure cylinder for removing organic matter, and a low-pressure cylinder for fluid-sand particle separation, thus achieving targeted impurity removal with high efficiency. Furthermore, the supercritical fluid diffuses more fully under different pressure environments, which is beneficial for improving fluid utilization.

Description

Technical Field

[0001] This utility model relates to the field of quartz sand purification technology, and in particular to a gradient pressure reactor for purifying quartz sand using supercritical methods. Background Technology

[0002] High-purity quartz sand is a core material for the semiconductor and photovoltaic industries, and its purity directly affects product performance. Traditional purification processes (such as acid washing and high-temperature chlorination) suffer from problems such as high pollution, high energy consumption, and limited purity improvement. Supercritical fluid (such as CO2) technology has become an emerging direction due to its green and efficient nature. However, existing supercritical reactors are mostly in a single pressure environment, while different impurities (metals, organic matter, inclusions) require different pressure conditions to dissolve effectively, resulting in low impurity removal efficiency. Furthermore, supercritical fluids do not diffuse sufficiently under uniform pressure, leading to low fluid utilization.

[0003] To address this issue, we propose a gradient pressure reactor that uses supercritical purification of quartz sand. Utility Model Content

[0004] The purpose of this invention is to provide a gradient pressure reactor that uses supercritical purification of quartz sand to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A gradient pressure reactor for supercritical purification of quartz sand includes a high-pressure cylinder, a medium-pressure cylinder, and a low-pressure cylinder separated along the axis, as well as a supercritical fluid injection system, a gradient pressure control system, and a control box. Heating jackets are provided on the outer walls of the high-pressure cylinder, the medium-pressure cylinder, and the low-pressure cylinder. A feed pipe is provided on the high-pressure cylinder, and a discharge pipe is provided at the bottom of the low-pressure cylinder. On / off valves are installed between adjacent feed pipes, high-pressure cylinders, medium-pressure cylinders, low-pressure cylinders, and discharge pipes. The gradient pressure control system includes a booster for the high-pressure cylinder, a pressure regulating valve for the medium-pressure cylinder, and a back pressure valve for the low-pressure cylinder.

[0007] In a further embodiment, the supercritical fluid injection system includes a preheater, a high-pressure pump, and an annular manifold that are interconnected, with the annular manifold located at the top inside the high-pressure cylinder, and downwardly inclined micropores evenly distributed along the circumferential direction on the outer wall of the annular manifold.

[0008] In a further embodiment, the pressure regulating valve and the back pressure valve are both connected in sequence to the quenching tower, the alkali spraying tower and the adsorption tower via pipelines.

[0009] In a further embodiment, a check valve is installed at the pipe connection end between the pressure regulating valve and the back pressure valve and the quench tower.

[0010] In a further embodiment, the high-pressure cylinder, medium-pressure cylinder, and low-pressure cylinder all adopt a conical cylinder structure that is wider at the top and narrower at the bottom, and the opening and closing valve is installed at the bottom of the conical cylinder.

[0011] In a further embodiment, pressure sensors and temperature sensors are installed on the inner walls of the high-pressure cylinder, medium-pressure cylinder, and low-pressure cylinder, and the pressure sensors and temperature sensors are electrically connected to the control box.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] This invention features a reactor with segmented pressure control. The high-pressure cylinder is used to dissolve metallic impurities, the medium-pressure cylinder is used to remove organic matter, and the low-pressure cylinder is used to achieve fluid-sand separation. This allows for targeted impurity removal with high efficiency. Furthermore, the supercritical fluid diffuses more fully under different pressure conditions, which helps improve fluid utilization. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model;

[0015] Figure 2 This is a schematic diagram of the installation structure of the high-pressure cylinder, medium-pressure cylinder, and low-pressure cylinder of this utility model;

[0016] Figure 3 This is a schematic diagram of the internal structure of the high-pressure cylinder of this utility model after cross-section.

[0017] In the diagram: 1. Control box; 2. High-pressure cylinder; 3. Medium-pressure cylinder; 4. Low-pressure cylinder; 5. Heating jacket; 6. Feed pipe; 7. Preheater; 8. High-pressure pump; 9. Discharge pipe; 10. On / off valve; 11. Booster pump; 12. Pressure regulating valve; 13. Back pressure valve; 14. Quenching tower; 15. Alkali spray tower; 16. Adsorption tower; 17. Check valve; 18. Pressure sensor; 19. Temperature sensor; 20. Annular diverter pipe. Detailed Implementation

[0018] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" 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 based on the specific circumstances.

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] Please see Figure 1-3 A gradient pressure reactor for supercritical purification of quartz sand includes a high-pressure cylinder 2, a medium-pressure cylinder 3, and a low-pressure cylinder 4 separated along the axial direction, as well as a supercritical fluid injection system, a gradient pressure control system, and a control box 1. The inner walls of the high-pressure cylinder 2, medium-pressure cylinder 3, and low-pressure cylinder 4 are lined with a corrosion-resistant alloy layer, and the outer walls are equipped with heating jackets 5. The heating jackets 5 use silicone rubber heating belts and are covered with stainless steel protective covers. A temperature sensor 19 (PT100 model) is embedded in the inner wall of each cylinder for temperature monitoring. The temperature sensor 19 and the silicone rubber heating belt are externally connected to the control box 1. The temperature sensor 19 transmits the detected data to the intelligent control unit inside the control box 1. The controller controls the heating power of the silicone rubber heating belt to achieve independent temperature control for each cylinder. The high-pressure cylinder 2 is equipped with a feed pipe 6 for adding quartz sand, and the low-pressure cylinder 4 is equipped with a discharge pipe 9 for discharging the purified quartz sand. On / off valves 10 are installed between adjacent feed pipes 6, high-pressure cylinder 2, medium-pressure cylinder 3, low-pressure cylinder 4 and discharge pipe 9 to ensure that each cylinder can work independently. The high-pressure cylinder 2, medium-pressure cylinder 3 and low-pressure cylinder 4 all adopt a conical structure that is wider at the top and narrower at the bottom, and the on / off valve 10 is installed at the bottom of the conical cylinder so that after the quartz sand is purified in the upper cylinder, it can automatically flow into the lower cylinder by opening the on / off valve 10.

[0022] The gradient pressure control system includes a booster pump 11, a pressure regulating valve 12, and a back pressure valve 13. The booster pump 11 is installed at the top inside the high-pressure cylinder 2. The inlet of the booster pump 11 is connected to a CO2 storage tank via a pipeline, and the outlet is connected to the inside of the high-pressure cylinder 2. The pressure regulating valve 12 is installed on the outer wall of the medium-pressure cylinder 3. The pressure regulating valve 12 detects the pressure before the valve in real time and automatically opens to release pressure. The back pressure valve 13 is installed on a pipeline connected to the outer wall of the low-pressure cylinder 4. The back pressure valve 13 is set with a target pressure, and the valve core opening is linearly related to the set pressure. After supercritical CO2 enters the low-pressure zone, it expands and vaporizes, and its volume increases tenfold. The back pressure valve 13 maintains the pressure in this zone through a throttling effect, and the gaseous CO2 is discharged from the pipeline. In order to better monitor the pressure information in each cylinder, pressure sensors 18, model Keller PA-33X-HAST, are embedded in the inner wall of each cylinder. The pressure sensors 18 are connected to the control box 1 and transmit the detected data to the intelligent controller in the control box 1 to achieve independent pressure control in each cylinder.

[0023] Considering that the chemical reaction of metallic impurities and organic matter during the supercritical CO2 purification process of quartz sand will release a variety of impurity gases, which will mix with CO2, in order to recover CO2, pressure regulating valve 12 and back pressure valve 13 are connected in sequence to quench tower 14, alkaline spray tower 15 and adsorption tower 16 through pipelines. The gas outlet pipe of adsorption tower 16 is connected to CO2 recovery tank. One-way valves 17 are installed at the pipeline connection ends of pressure regulating valve 12 and back pressure valve 13 and quench tower 14 to prevent gas from mixing in the two pipelines. The CO2 recovered in medium pressure cylinder 3 and low pressure cylinder 4 can be purified by quench tower 14, alkaline spray tower 15 and adsorption tower 16.

[0024] The supercritical fluid injection system includes a preheater 7, a high-pressure pump 8, and an annular diverter 20 that are interconnected. The preheater 7 and the high-pressure pump 8 are located outside the high-pressure cylinder 2. The preheater 7 is a serpentine heat exchanger that is wound around the outlet pipe of the high-pressure pump 8 and covered with a ceramic insulation layer. It is used to preheat the supercritical fluid. The annular diverter 20 is located at the top inside the high-pressure cylinder 2. The outer wall of the annular diverter 20 is provided with downwardly inclined micropores evenly distributed along the circumference to facilitate the diversion and injection of supercritical fluid.

[0025] Workflow: First, open the valve 10 between the feed pipe 6 and the high-pressure cylinder 2, and feed in quartz sand, which is then fed into the high-pressure cylinder 2 through the feed pipe 6. Close the valve 10 between the feed pipe 6 and the high-pressure cylinder 2. At 25 MPa / 60℃, CO2 dissolves metallic impurities such as Fe and Al. Then, open the valve 10 between the high-pressure cylinder 2 and the medium-pressure cylinder 3, and the sand particles fall into the medium-pressure cylinder 3. Close the valve 10 between the high-pressure cylinder 2 and the medium-pressure cylinder 3. At 15 MPa / 50℃, organic matter is removed. Next, open the valve 10 between the medium-pressure cylinder 3 and the low-pressure cylinder 4, and the sand particles enter the low-pressure cylinder 4. Close the valve 10 between the medium-pressure cylinder 3 and the low-pressure cylinder 4. At 8 MPa / 40℃, CO2 is vaporized and enters the impurity removal tower group through the back pressure valve 13 for impurity removal and recovery. Finally, open the valve 10 between the low-pressure cylinder 4 and the discharge pipe 9, and the purified quartz sand is discharged through the discharge pipe 9.

[0026] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A gradient pressure reactor using supercritical purified quartz sand, characterized in that, The system includes a high-pressure cylinder (2), a medium-pressure cylinder (3), and a low-pressure cylinder (4) separated along the axial direction, as well as a supercritical fluid injection system, a gradient pressure control system, and a control box (1). The outer walls of the high-pressure cylinder (2), the medium-pressure cylinder (3), and the low-pressure cylinder (4) are all equipped with heating jackets (5). The high-pressure cylinder (2) is equipped with a feed pipe (6), and the low-pressure cylinder (4) is equipped with a discharge pipe (9). The feed pipe (6), the high-pressure cylinder (2), the medium-pressure cylinder (3), the low-pressure cylinder (4), and the discharge pipe (9) are all equipped with on / off valves (10). The gradient pressure control system includes a booster pump (11) for the high-pressure cylinder (2), a pressure regulating valve (12) for the medium-pressure cylinder (3), and a back pressure valve (13) for the low-pressure cylinder (4).

2. The gradient pressure reactor for supercritical purification of quartz sand according to claim 1, characterized in that: The supercritical fluid injection system includes a preheater (7), a high-pressure pump (8), and an annular diverter (20) that are interconnected. The annular diverter (20) is located at the top inside the high-pressure cylinder (2), and downwardly inclined micropores are evenly distributed along the circumference on the outer wall of the annular diverter (20).

3. A gradient pressure reactor for supercritical purification of quartz sand according to claim 1, characterized in that: The pressure regulating valve (12) and the back pressure valve (13) are connected in sequence to the quench tower (14), the alkaline spray tower (15) and the adsorption tower (16) via pipelines.

4. A gradient pressure reactor for supercritical purification of quartz sand according to claim 3, characterized in that: One-way valves (17) are installed at the pipe connection ends of the pressure regulating valve (12) and back pressure valve (13) to the quench tower (14).

5. A gradient pressure reactor for supercritical purification of quartz sand according to claim 1, characterized in that: The high-pressure cylinder (2), medium-pressure cylinder (3) and low-pressure cylinder (4) all adopt a conical cylinder structure that is wider at the top and narrower at the bottom, and the opening and closing valve (10) is installed at the bottom of the conical cylinder.

6. A gradient pressure reactor for supercritical purification of quartz sand according to claim 1, characterized in that: Pressure sensors (18) and temperature sensors (19) are installed on the inner walls of the high-pressure cylinder (2), medium-pressure cylinder (3) and low-pressure cylinder (4), and the pressure sensors (18) and temperature sensors (19) are electrically connected to the control box (1).

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