A photovoltaic silicon wafer cutting fluid preparation mixing device

Abstract

This utility model discloses a mixing device for preparing photovoltaic silicon wafer cutting fluid, belonging to the field of mixing technology. It includes a base, with a mixing tank mounted on the upper surface of the base via several circumferentially distributed support parts. A matching cover is mounted on the top of the mixing tank, with a feed inlet on the cover. A constant-temperature chamber is formed on the side wall of the mixing tank. A stirring shaft is installed inside the mixing tank, with its top extending through the cover and connected to a mixing motor. Turbine blades are mounted at the bottom of the stirring shaft, and propeller blades are positioned below the turbine blades. A scraper blade is located in the middle of the stirring shaft, its blades resting against the inner side wall of the mixing tank. A discharge pipe is connected to the bottom of the mixing tank, and a switch valve is located on the discharge pipe at the bottom of the mixing tank. The feed inlet at the bottom of the mixing tank is connected to a feeding pipe via a vacuum pump. This utility model ensures uniform mixing and guarantees a high cutting yield in photovoltaic silicon wafer cutting.

Description

Technical Field

[0001] This utility model relates to the field of mixing technology, and in particular to a mixing device for preparing photovoltaic silicon wafer cutting fluid. Background Technology

[0002] The photovoltaic silicon wafer cutting fluid mainly uses diamond wire cutting fluid (current mainstream technology, with better environmental performance), and its main components include:

[0003] 1. Base solution (60%-80%)

[0004] Deionized water: As the main solvent, it has low cost and high heat dissipation efficiency, and its proportion is significantly higher than that of traditional processes.

[0005] Water-soluble polymers, such as polyethylene glycol (PEG) and sodium polyacrylate (PAA), can replace PEG in traditional mortars, reducing the amount used to 10%-20%, and improving suspension and lubricity by adjusting the molecular chain structure.

[0006] 2. Functional additives (20%-40%, core technology barrier)

[0007] Lubricants: Fatty acid esters, such as triethanolamine oleate, form an oil film at the cutting interface, reducing the coefficient of friction between the diamond wire and the silicon wafer (down to below 0.1), and reducing wire marks and edge chipping. Extreme pressure anti-wear agents, such as sulfur- and phosphorus-containing organic compounds, react with the metal surface under high temperature and pressure to form a protective film, preventing the diamond wire from wearing and breaking.

[0008] Dispersants such as polyacrylic acid (PAA) and polycarboxylate can uniformly disperse the silicon powder (particle size 1-5um) produced by cutting through electrostatic repulsion and steric hindrance, thus avoiding agglomeration and clogging of the wire mesh.

[0009] Rust inhibitors, such as benzotriazole (BTA), protect the metal parts of cutting equipment (such as stainless steel guide wheels) from corrosion.

[0010] Surfactants, such as fatty alcohol polyoxyethylene ether (AEO), reduce the surface tension of the cutting fluid (down to below 30 mN / m), enhancing the penetration and cleaning effect on the silicon wafer surface.

[0011] During the cutting process, the high-speed rotation of the diamond wire generates a large amount of heat. If the cutting fluid is not mixed evenly, insufficient local cooling capacity can cause a sudden rise in the temperature of materials such as silicon wafers or sapphire, potentially leading to the following problems: thermal damage to the material surface (such as edge chipping and cracking); accelerated wear of the diamond wire due to high temperatures, even wire breakage, increasing the frequency of consumable replacement. Simultaneously, uneven lubrication can increase cutting resistance, affecting cutting speed and surface finish. Therefore, the uniformity of the cutting fluid mixing directly affects the cutting yield. Based on this, this invention proposes a mixing device for preparing photovoltaic silicon wafer cutting fluid. Utility Model Content

[0012] The purpose of this invention is to provide a mixing device for preparing photovoltaic silicon wafer cutting fluid, thereby solving the aforementioned problems.

[0013] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0014] This utility model discloses a mixing device for preparing photovoltaic silicon wafer cutting fluid, comprising a base, a mixing tank being mounted on the upper surface of the base via several circumferentially distributed support portions, a matching cover being mounted on the top of the mixing tank, and a feed inlet being mounted on the cover; a constant temperature chamber being formed on the side wall of the mixing tank, a stirring shaft being mounted inside the mixing tank, the top of the stirring shaft extending through the cover and connected to a mixing motor, a turbine blade being mounted at the bottom of the stirring shaft, a propeller blade being mounted below the turbine blade, and a scraper blade being mounted in the middle of the stirring shaft, the scraper blade abutting against the inner side wall of the mixing tank; a discharge pipe being connected to the bottom of the mixing tank, and a switch valve being mounted on the discharge pipe at the bottom of the mixing tank; a vacuum pump being connected to the bottom feed inlet of the mixing tank via a pipeline, and a feeding pipe being connected to the feed inlet of the vacuum pump.

[0015] Furthermore, the constant temperature chamber is provided with a water inlet at the bottom and a water outlet at the top.

[0016] Furthermore, the propulsion blades are spirally distributed on the stirring shaft.

[0017] Furthermore, the switching valve includes a valve body, with connecting plates at its upper and lower ends for connecting the bottom outlet of the mixing tank and the outlet pipe, respectively; a limiting groove is formed on the inner side wall of the valve body, and a switching valve plate is inserted into the limiting groove; a telescopic rod is provided at one end of the outer side wall of the switching valve plate; a valve plate placement cavity matching the switching valve plate is provided at one end of the valve body near the telescopic rod; the end of the valve plate placement cavity away from the valve body is connected to the limiting cavity through a connector; and the other end of the telescopic rod can slide out of the limiting cavity and is connected to a telescopic drive device.

[0018] Furthermore, the telescopic drive device includes a pneumatic cylinder, a hydraulic cylinder, and an electric push rod.

[0019] Furthermore, the feeding pipe is mounted on the outer wall of the mixing tank by a number of mounting plates that are equidistantly distributed vertically.

[0020] Furthermore, a vacuum gauge is installed on the feeding tube.

[0021] Furthermore, a sampling port is provided on the outer wall of the mixing tank, and a valve is provided on the sampling port.

[0022] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0023] This utility model relates to a mixing device for preparing photovoltaic silicon wafer cutting fluid. By injecting hot / cold water into the constant temperature chamber of the mixing tank, the internal temperature of the mixing tank is kept constant, preventing the cutting fluid from solidifying due to low temperature or generating a large number of bubbles due to high temperature. Then, through the cooperation of turbine blades, propeller blades and scraper blades, the functional additives fed from the bottom are fully and evenly mixed with the base fluid, thereby ensuring the cutting yield in photovoltaic silicon wafer cutting. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings.

[0025] Figure 1 A schematic diagram of the mixing device for preparing photovoltaic silicon wafer cutting fluid according to this utility model;

[0026] Figure 2 Cross-sectional view of the mixing device for preparing photovoltaic silicon wafer cutting fluid according to this utility model;

[0027] Figure 3 This is a schematic diagram of the on / off valve structure;

[0028] Figure 4 This is a sectional view of the on / off valve;

[0029] Figure 5 Front view of the mixing device for preparing photovoltaic silicon wafer cutting fluid according to this utility model;

[0030] Explanation of reference numerals in the attached drawings: 1. Base; 2. Support; 3. Mixing tank; 4. Cover; 5. Inlet; 6. Mixing motor; 7. Feed pipe; 8. Mounting plate; 9. Vacuum pump; 10. Vacuum gauge; 11. Discharge pipe; 12. Water inlet; 13. Water outlet; 14. Constant temperature chamber; 15. Stirring shaft; 16. Turbine blade; 17. Scraper blade; 18. Switch valve; 19. Sampling port;

[0031] 1801, Valve body; 1802, Limiting groove; 1803, Connecting plate; 1804, Switch valve plate; 1805, Valve plate placement cavity; 1806, Connecting piece; 1807, Telescopic rod; 1808, Limiting cavity. Detailed Implementation

[0032] like Figure 1-5 As shown, a mixing device for preparing photovoltaic silicon wafer cutting fluid includes a base 1. A mixing tank 3 is installed on the upper surface of the base 1 through several circumferentially distributed support parts 2. A matching cover 4 is installed on the top of the mixing tank 3. A feed inlet 5 is installed on the cover 4, which is mainly used for feeding the base fluid.

[0033] A thermostatic chamber 14 is formed on the side wall of the mixing tank 3. A water inlet 12 is installed at the bottom of the thermostatic chamber 14, and a water outlet 13 is installed at the top. Hot / cold water enters the thermostatic chamber 14 through the water inlet 12, exchanges heat, and is then discharged through the water outlet 13. This cycle repeats to maintain a constant temperature within the mixing tank 3, preventing problems such as the cutting fluid solidifying at low temperatures or generating numerous bubbles at high temperatures, and ensuring uniform mixing. Specifically, a temperature sensor is installed inside the mixing tank 3 to detect temperature changes, which are displayed on the outer wall of the mixing tank 3 for easy viewing.

[0034] A stirring shaft 15 is installed inside the mixing tank 3. The top of the stirring shaft 15 extends through the cover 4 and is connected to a mixing motor 6. A turbine blade 16 is installed at the bottom of the stirring shaft 15, which propels the material towards the side wall, creating a strong shear zone in the middle of the tank, facilitating the initial dispersion of functional additives. Below the turbine blade 16, a propeller blade is installed, spirally distributed on the stirring shaft 15, pushing the material up and down along the shaft to form a "suction-discharge" convection, improving the overall material migration efficiency. A scraper blade 17 is installed in the middle of the stirring shaft 15, with its blades abutting against the inner side wall of the mixing tank 3. The side wall blades, through their close-to-wall movement (scraper scraping), push the material into the main flow field, i.e., propelling the near-wall material towards the center, thus superimposing the flow field of the central blade (turbine blade 16).

[0035] 1) The central blades lift the material from the bottom up, while the side blades squeeze the near-wall material towards the center, forming a "radial-axial" composite convection that shortens the material circulation path and reduces the mixing blind zone.

[0036] 2) The mainstream flow of the central blade and the auxiliary flow of the sidewall blades form a velocity gradient at the intersection, which enhances the collision and shearing of fluid micro-particles, promotes material dispersion, and avoids agglomeration.

[0037] The bottom inlet of the mixing tank 3 is connected to a vacuum pump 9 via a pipeline. The inlet of the vacuum pump 9 is connected to a feeding pipe 7. Under the action of the vacuum pump 9, the functional additives are directly added below the surface of the base liquid, reducing air entrainment, which is beneficial for uniform mixing and reducing the generation of bubbles.

[0038] The bottom of the mixing tank 3 is connected to a discharge pipe 11. A switch valve 18 is installed at the bottom of the discharge pipe 11 to prevent unmixed material from entering the discharge pipe 11. The switch valve 18 includes a valve body 1801, and connecting plates 1803 for connecting the bottom discharge port of the mixing tank 3 and the discharge pipe 11 are respectively installed at the upper and lower ends of the valve body 1801. A limiting groove 1802 is formed on the inner side wall of the valve body 1801, and a switch valve plate 1804 is inserted into the limiting groove 1802. A sealing element is installed between the limiting groove 1802 and the switch valve plate 1804. A telescopic rod 1807 is installed at one end of the outer wall of the switch valve plate 1804. A valve plate placement cavity 1805, matching the switch valve plate 1804, is installed at one end of the valve body 1801 near the telescopic rod 1807. The end of the valve plate placement cavity 1805 away from the valve body 1801 is connected to a limiting cavity 1808 via a connector 1806. The other end of the telescopic rod 1807 can slide out of the limiting cavity 1808 and is connected to a telescopic drive device. The telescopic drive device drives the telescopic rod 1807 to extend and retract left and right, thereby adjusting the switching state of the switch valve plate 1804.

[0039] The telescopic drive device includes a pneumatic cylinder, a hydraulic cylinder, and an electric push rod.

[0040] The feeding pipe 7 is installed on the outer wall of the mixing tank 3 through several mounting plates 8 that are equidistantly distributed vertically.

[0041] A vacuum gauge 10 is installed on the feeding pipe 7.

[0042] A sampling port 19 is provided on the outer wall of the mixing tank 3. A valve is installed on the sampling port 19. By opening the valve, the mixed liquid in the mixing tank 3 can be taken out for testing of indicators such as concentration, conductivity, and pH.

[0043] The operation process of this utility model is as follows:

[0044] First, hot / cold water inlet 12 enters the constant temperature chamber 14 and exits from water outlet 13, forming a circulation and creating a constant temperature (20-30℃) environment in mixing tank 3. Then, base liquid and filter press liquid (clear liquid obtained after processing waste liquid after cutting by a filter press) are added to mixing tank 3 in a certain proportion and stirred (stirred for 15 minutes) to obtain the liquid to be adjusted. Then, the liquid to be adjusted is sampled through sampling port 19 for concentration, conductivity, pH and other indicators testing. Finally, after passing the tests, functional additives are added to the liquid to be adjusted in a certain proportion and stirred (stirred for 15 minutes) to obtain the finished liquid. The finished liquid is sampled through sampling port 19 for various indicators testing. If the test fails, it is re-adjusted. After passing the test, the switch valve 18 is opened and the liquid is discharged from the discharge pipe 11.

[0045] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A mixing device for preparing photovoltaic silicon wafer cutting fluid, characterized in that: The system includes a base (1), on which a mixing tank (3) is provided by several circumferentially distributed support parts (2) on the upper surface of the base (1). A matching cover (4) is provided on the top of the mixing tank (3), and a feed inlet (5) is provided on the cover (4). A constant temperature chamber (14) is provided on the side wall of the mixing tank (3). A stirring shaft (15) is provided inside the mixing tank (3). The top of the stirring shaft (15) extends out of the cover (4) and is connected to a mixing motor (6). A turbine blade (1) is provided at the bottom of the stirring shaft (15). 6) A propulsion blade is provided below the turbine blade (16), and a scraper blade (17) is provided in the middle of the stirring shaft (15). The blade of the scraper blade (17) abuts against the inner wall of the mixing tank (3). The bottom of the mixing tank (3) is connected to the discharge pipe (11), and the discharge pipe (11) is provided with a switch valve (18) at the bottom of the mixing tank (3). The bottom inlet of the mixing tank (3) is connected to the vacuum pump (9) through a pipeline, and the inlet of the vacuum pump (9) is connected to the feeding pipe (7).

2. The mixing device for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: The constant temperature chamber (14) is provided with a water inlet (12) at the bottom and a water outlet (13) at the top.

3. The mixing device for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: The propulsion blades are spirally distributed on the stirring shaft (15).

4. The mixing device for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: The switching valve (18) includes a valve body (1801), and the upper and lower ends of the valve body (1801) are respectively provided with connecting plates (1803) for connecting the bottom outlet of the mixing tank (3) and the outlet pipe (11); a limiting groove (1802) is opened on the inner side wall of the valve body (1801), and a switching valve plate (1804) is inserted into the limiting groove (1802). A telescopic rod is provided at one end of the outer side wall of the switching valve plate (1804). 1807), the valve body (1801) is provided with a valve plate placement cavity (1805) matching the switch valve plate (1804) at one end near the telescopic rod (1807), the valve plate placement cavity (1805) away from the valve body (1801) is connected to the limiting cavity (1808) through the connector (1806), and the other end of the telescopic rod (1807) can slide out of the limiting cavity (1808) and is connected to the telescopic drive device.

5. The mixing apparatus for preparing photovoltaic silicon wafer cutting fluid according to claim 4, characterized in that: The telescopic drive device includes a pneumatic cylinder, a hydraulic cylinder, and an electric push rod.

6. The mixing apparatus for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: The feeding pipe (7) is installed on the outer wall of the mixing tank (3) through several mounting plates (8) that are equidistantly distributed vertically.

7. The mixing apparatus for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: A vacuum gauge (10) is installed on the feed pipe (7).

8. The mixing apparatus for preparing photovoltaic silicon wafer cutting fluid according to claim 1, characterized in that: A sampling port (19) is provided on the outer wall of the mixing tank (3), and a valve is provided on the sampling port (19).

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