Silica sol preparation device

Abstract

The utility model discloses a silica sol preparation device which comprises a reaction kettle, a feed port, a return port, a discharge port and a feed port are arranged on the reaction kettle, the feed port is communicated with the return port through a high-temperature pump, a liquid level meter and a stirrer are mounted in the reaction kettle, a jacket is arranged on the periphery of the reaction kettle, and the feed port is communicated with the return port. And the jacket is provided with a steam inlet, a steam condensate outlet, a cooling water inlet and a cooling water outlet. According to the utility model, the constant liquid level control in the growth process of silica sol particles at high temperature can be realized, the number of large particles in silica sol can be effectively reduced, and meanwhile, the growth uniformity of materials can be effectively controlled through the internal stirring and external circulation modes of the reaction kettle.

Description

Technical Field

[0001] The utility model belongs to the technical field of silica sol preparation equipment, and particularly relates to a silica sol preparation device. Background Art

[0002] Silica sol, also known as colloidal silica, is a dispersion of silicon dioxide nanoparticles in water and is widely used in catalysts, fibers, coatings, casting, etc. In recent years, it has been widely used as abrasive particles in fields such as chemical mechanical polishing (CMP). When used as a CMP abrasive, higher quality requirements are often imposed on silica sol.

[0003] The ion exchange method is a commonly used method for the industrial preparation of silica sol and is widely adopted at home and abroad due to its low cost. However, there are also problems such as a high content of large particles and poor particle uniformity, which sometimes limit its application in CMP. The quality of silica sol is not only related to the preparation process but also has a great relationship with the reaction device. In the traditional ion exchange method for synthesizing silica sol, the exchanged silicic acid is added to the reaction kettle, and the growth of silica sol nanoparticles is completed in the reaction kettle. During the growth process, a constant liquid level growth process is generally adopted, and the liquid level is observed manually. When fluctuations occur, the feeding speed of silicic acid is adjusted manually. Manual observation and adjustment will cause large errors, and the liquid level fluctuation range is large, resulting in serious crystallization on the reaction kettle wall, affecting the service life of the reaction kettle. At the same time, the large particles generated by crystallization enter the silica sol, which will cause large particle scratching defects during the CMP polishing process and affect the use effect. In addition, a stirrer is generally used in the reaction kettle for the reaction and mixing of substances, but the stirring of the stirrer is often not uniform, and there will be asymmetry in the flow. During the reaction process, the uniformity of the reaction liquid is very important for the reaction rate and product quality. When the materials in the reaction kettle are not stirred evenly, the uniformity of the silica sol nanoparticles will become poor, affecting the polishing effect. Content of the Utility Model

[0004] In order to solve the above technical problems, the utility model provides a silica sol preparation device, which can effectively solve the problem of constant liquid level control during the silica sol preparation process, effectively reduce the crystallization on the reaction kettle wall, reduce the number of large particles (particles ≥ 0.56 microns) in the silica sol, and at the same time, the combination of stirring and external circulation in the reaction kettle can effectively improve the reaction and mixing uniformity of the materials.

[0005] The technical solution adopted by the utility model is as follows: A silica sol preparation device includes a reaction kettle, on which there are a feed inlet, a return feed inlet, a discharge outlet, and a feed outlet. The feed inlet and the return feed inlet are respectively located at the upper end of the reaction kettle, and the discharge outlet and the feed outlet are respectively located at the lower end of the reaction kettle. The feed outlet and the return feed inlet are connected through a high-temperature pump. A liquid level gauge and a stirrer are installed inside the reaction kettle. An electromagnetic valve is installed at the feed inlet, and control valves are respectively installed at the discharge outlet and the feed outlet. The liquid level gauge is connected to a liquid level control panel, and the liquid level control panel controls the electromagnetic valve. There is a jacket around the reaction kettle, and there are a steam inlet, a steam condensate outlet, a cooling water inlet, and a cooling water outlet on the jacket. Valves are respectively installed at the steam inlet, the steam condensate outlet, the cooling water inlet, and the cooling water outlet. The steam inlet is connected to high-temperature steam through a steam pipeline, and the cooling water inlet is connected to cooling water through a cooling water pipeline.

[0006] As a preference of the above technical solution, an exhaust port is provided at the upper end of the reaction kettle, and a cover plate is covered at the exhaust port.

[0007] As a preference of the above technical solution, the steam inlet and the cooling water outlet are respectively located on both sides of the upper end of the jacket, and the steam condensate outlet and the cooling water inlet are respectively located on both sides of the lower end of the jacket.

[0008] As a preference of the above technical solution, the stirrer is a paddle stirrer.

[0009] As a preference of the above technical solution, the reaction kettle is an enamel reaction kettle or a stainless steel reaction kettle.

[0010] As a preference of the above technical solution, the liquid level gauge is a non-contact radar liquid level gauge, and the non-contact radar liquid level gauge is installed at the upper end of the reaction kettle.

[0011] The beneficial effects of the utility model are as follows: The utility model adopts a non-contact radar liquid level gauge to monitor in real time the liquid level change of the silica sol material in the reaction kettle under high temperature dynamics, and feeds back the real-time monitored data to the liquid level control panel. The liquid level fluctuation is associated with the silicic acid feeding speed through the control program of the liquid level control panel, and the silicic acid feeding speed is automatically controlled and adjusted through the signal output by the control panel to maintain the constant liquid level in the reaction kettle, greatly reducing the crystallization problem on the wall of the reaction kettle and effectively reducing the number of large particles (particles with a size ≥ 0.56 microns) in the silica sol. While the utility model uses a stirrer for stirring, the bottom material in the reaction kettle is transported through a high-temperature pump to the top return feed inlet of the reaction kettle through an external pipeline and then returns to the reaction kettle. This material external circulation method can effectively break the asymmetry of liquid flow, promote the mixing and contact frequency of reaction materials, and improve the uniformity of the reaction. Description of the Drawings

[0012] Figure 1 is the structural schematic diagram of the utility model. Detailed Implementation Manner

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without making creative efforts shall fall within the protection scope of the present utility model.

[0014] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0015] In the description of the present utility model, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "connected", "connected to" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0016] Such as Figure 1As shown in the figure, a silica sol preparation device includes a reaction kettle 1. The reaction kettle 1 is provided with a feed inlet 6, a return feed port 7, a discharge port 8, and a feeding port 9. The feed inlet 6 and the return feed port 7 are respectively located at the upper end of the reaction kettle 1, and the discharge port 8 and the feeding port 9 are respectively located at the lower end of the reaction kettle 1. The feeding port 9 and the return feed port 7 are connected through a high-temperature pump 2. A liquid level gauge 3 and a stirrer 5 are installed in the reaction kettle 1. An electromagnetic valve is installed at the feed inlet 6, and control valves are respectively installed at the discharge port 8 and the feeding port 9. The liquid level gauge 3 is connected to a liquid level control panel 4, and the liquid level control panel 4 controls the electromagnetic valve. A jacket is provided around the reaction kettle 1, and the jacket is provided with a steam inlet 10, a steam condensate outlet 11, a cooling water inlet 12, and a cooling water outlet 13. Valves are respectively installed at the steam inlet 10, the steam condensate outlet 11, the cooling water inlet 12, and the cooling water outlet 13. The steam inlet 10 is connected to high-temperature steam through a steam pipeline, and the cooling water inlet 12 is connected to cooling water through a cooling water pipeline. Reaction materials are added into the reaction kettle 1 through the feed inlet 6. The liquid level gauge 3 senses the liquid level height in the reaction kettle 1. The stirrer 5 is used to stir the materials in the reaction kettle 1. High-temperature and high-pressure steam is filled into the jacket through the steam inlet 10 to heat the reaction kettle 1 and promote the reaction. The condensate formed by the condensation of the high-temperature and high-pressure steam is discharged from the cooling water outlet 13. The high-temperature pump 2 pumps the reaction materials out from the feeding port 9 and returns them to the reaction kettle 1 from the return feed port 7. Cooling water is filled into the jacket through the cooling water inlet 12, and the cooling water is discharged from the cooling water outlet 13. The circulating cooling water is used to cool the reaction kettle 1.

[0017] Further, an exhaust port 14 is provided at the upper end of the reaction kettle 1, and a cover plate is covered at the exhaust port 14. The air pressure in the reaction kettle 1 is controlled by using the exhaust port 14 to prevent potential safety hazards caused by excessive air pressure. In order to monitor the air pressure in the reaction kettle 1, a pressure gauge can also be installed on the reaction kettle 1.

[0018] Further, the steam inlet 10 and the cooling water outlet 13 are respectively located on both sides of the upper end of the jacket, and the steam condensate outlet 11 and the cooling water inlet 12 are respectively located on both sides of the lower end of the jacket. The jacket can be shared, or two sets of jackets can be provided. One set of jackets is connected to the steam inlet 10 and the steam condensate outlet 11, and the other set of jackets is connected to the cooling water inlet 12 and the cooling water outlet 13. When only one set of jackets is used, the cooling water inlet 12 and the cooling water outlet 13 can be opened only after the steam inlet 10 and the steam condensate outlet 11 are closed.

[0019] Further, the stirrer 5 is a paddle stirrer 5. While the paddle stirrer 5 stirs the materials, the materials at the bottom of the reaction kettle 1 are transported to the top return feed port 7 of the reaction kettle 1 through the high-temperature pump 2 via an external pipeline and then return to the reaction kettle 1. This external material circulation method can effectively destroy the asymmetry of liquid flow, promote the mixing and contact frequency of reaction materials, and improve the uniformity of the reaction.

[0020] Furthermore, the reaction kettle 1 is an enamel reaction kettle 1 or a stainless steel reaction kettle 1.

[0021] Furthermore, the liquid level gauge 3 is a non-contact radar liquid level gauge 3, and the non-contact radar liquid level gauge 3 is installed at the upper end of the reaction kettle 1. The non-contact radar liquid level gauge 3 monitors the liquid level change of the silica sol material in the reaction kettle 1 in real time under high temperature dynamics, and feeds back the real-time monitored data to the liquid level control panel 4. The liquid level fluctuation is correlated with the silica feeding speed through the control program of the liquid level control panel 4, and the silica feeding speed is automatically controlled and adjusted through the signal output by the control panel 4 to maintain a constant liquid level in the reaction kettle, greatly reducing the crystallization problem of the reaction kettle wall and effectively reducing the number of large particles in the silica sol. The liquid level control panel 4 uses a commercially available PLC circuit board.

[0022] The working process of the silica sol preparation device of this embodiment is as follows:

[0023] First, a certain amount of silica sol seeds are added into the reaction kettle 1 through the feed inlet 6, and are stirred evenly by the stirrer 5. Then, steam is introduced from the steam inlet 10 on the jacket to heat up the materials in the reaction kettle 1, and the steam condensate hot water is discharged from the steam condensate outlet 11. The radar liquid level gauge 3 is turned on for real-time liquid level monitoring. When the temperature of the materials in the reaction kettle 1 reaches 100 °C, the materials in the reaction kettle 1 are transported to the high-temperature pump 2 through the feed port 9, and then pumped by the high-temperature pump 2 to the return port 7 to be mixed with the materials in the reaction kettle 1. Then, silica acid is added from the feed inlet 6 at a certain feeding speed. The silica acid deposits and condenses on the silica sol seed particles, causing the seeds to grow. When the volume of the materials in the reaction kettle 1 reaches the set high liquid level, the liquid level control panel 4 will automatically and dynamically adjust the silica acid feeding speed according to the real-time liquid level fluctuation to maintain a constant liquid level. When the required silica sol particle size requirement is reached, after the preparation reaction is completed, the silica acid feeding is stopped, the steam input is closed, and after maintaining the temperature for a certain time, cooling water is introduced from the cooling water inlet 13 to cool down the materials in the reaction kettle 1, and the cooling water is discharged from the cooling water outlet 14 through the jacket. After the cooling is completed, the materials in the reaction kettle 1 are transported from the discharge port 8 to the designated storage tank. Thus, it can be seen that the present utility model can achieve constant liquid level control during the growth process of silica sol particles at high temperature, can effectively reduce the number of large particles (particles with a size ≥ 0.56 micrometers) in the silica sol, and at the same time, the stirring and external circulation methods in the reaction kettle can effectively control the growth uniformity of the materials.

[0024] It is worth mentioning that technical features such as the liquid level control panel 4 involved in the patent application of the present utility model should be regarded as prior art. The specific structures, working principles, and possible control methods and spatial layout methods of these technical features can be selected conventionally in the art, and should not be regarded as the inventive points of the patent of the present utility model, and the present utility model patent will not be further specifically elaborated.

[0025] The preferred specific embodiments of the present utility model have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present utility model without creative efforts. Therefore, all technical solutions that can be obtained by those skilled in the art in this technical field based on the concept of the present utility model through logical analysis, reasoning, or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. A silica sol preparation device, characterized in that, It includes a reactor, on which there are a feed inlet, a return feed inlet, a discharge outlet and a feeding outlet. The feed inlet and the return feed inlet are respectively located at the upper end of the reactor, and the discharge outlet and the feeding outlet are respectively located at the lower end of the reactor. The feeding outlet and the return feed inlet are connected through a high-temperature pump. A liquid level gauge and a stirrer are installed in the reactor. An electromagnetic valve is installed at the feed inlet, and control valves are respectively installed at the discharge outlet and the feeding outlet. The liquid level gauge is connected to a liquid level control panel, and the liquid level control panel controls the electromagnetic valve. There is a jacket around the reactor, and there are a steam inlet, a steam condensate outlet, a cooling water inlet and a cooling water outlet on the jacket. Valves are respectively installed at the steam inlet, the steam condensate outlet, the cooling water inlet and the cooling water outlet. The steam inlet is connected to high-temperature steam through a steam pipeline, and the cooling water inlet is connected to cooling water through a cooling water pipeline.

2. The silica sol preparation device according to claim 1, wherein An exhaust port is provided at the upper end of the reactor, and a cover plate is covered at the exhaust port.

3. The silica sol preparation device according to claim 1, characterized in that, The steam inlet and the cooling water outlet are respectively located on both sides of the upper end of the jacket, and the steam condensate outlet and the cooling water inlet are respectively located on both sides of the lower end of the jacket.

4. The silica sol preparation device according to claim 1, characterized in that, The stirrer is a paddle stirrer.

5. The silica sol preparation device according to claim 1, characterized in that, The reactor is an enamel reactor or a stainless steel reactor.

6. The silica sol preparation device according to claim 1, characterized in that, The liquid level gauge is a non-contact radar liquid level gauge, and the non-contact radar liquid level gauge is installed at the upper end of the reactor.

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