Treatment equipment for polycrystalline silicon production wastewater

Abstract

The invention relates to polycrystalline silicon production wastewater treatment equipment which comprises a wastewater storage tank, a silicon-containing wastewater screw pump, a PAM (polyacrylamide) dosing unit, a dehydrator, a sludge outlet conveyor and an overlying system, and the wastewater storage tank is communicated with the dehydrator through a silicon-containing wastewater conveying assembly; the invention relates to the technical field of silicon-containing wastewater treatment. According to the treatment equipment for the polycrystalline silicon production wastewater, in the conveying process, silicon-containing wastewater can be automatically subjected to filter pressing without stopping stirring, the silicon-containing wastewater and sewage can be effectively and preliminarily separated, treatment can be carried out without stopping the machine, the height of a filter pressing ring can be adjusted at any time, and normal stirring work of a stirring assembly above the filter pressing ring cannot be interfered.

Description

Technical Field

[0001] The invention relates to the technical field of silicon-containing wastewater treatment, in particular to equipment for treating polysilicon production wastewater. Background Art

[0002] With the advancement of science and technology and the improvement of environmental awareness, the production and use of solar photovoltaic materials have entered a rapid growth stage; as an important raw material for solar photovoltaic materials, the industrial production demand of polysilicon has also increased rapidly. Polysilicon mainly adopts multi-wire cutting technology. During the cutting process, about 50% of the silicon material is mixed into the cutting fluid composed of polyethylene glycol cutting fluid and silicon carbide powder abrasive, which makes the composition, particle size and hardness of the micro powder in the cutting fluid fail to meet the standards, resulting in a decrease in cutting performance and cannot be reused. Therefore, during the cutting process, the old cutting fluid needs to be continuously discharged and the new cutting fluid is continuously added, which generates a large amount of cutting wastewater. The wastewater generated in the production process of polysilicon contains high concentrations of fluoride ions, chloride ions and various heavy metal ions. Direct discharge will cause serious pollution to the environment. The production tail gas of polysilicon mainly contains a large amount of HCl, chlorosilane (SiHCl3, SiH2Cl2, SiCl4), H2, N2. Since chlorosilane is easily hydrolyzed, alkali washing is often used, such as dilute NaOH solution and lime milk.

[0003] The existing silicon-containing wastewater treatment equipment cannot effectively filter the silicon-containing wastewater to separate the internal sewage and solid residue. Therefore, a device is proposed that can effectively filter the silicon-containing wastewater while stirring and conveying, which can quickly perform preliminary separation of silicon water. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a treatment device for polysilicon production wastewater, which solves the above-mentioned problems.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a polysilicon production wastewater treatment device, comprising a wastewater storage tank, a silicon-containing wastewater screw pump, a PAM dosing unit and a dehydrator, wherein the wastewater storage tank and the dehydrator are connected through a silicon-containing wastewater conveying component; The silicon-containing wastewater conveying assembly comprises a stirring and conveying box, the bottom of the inner cavity of the stirring and conveying box is connected to the wastewater storage tank through a mud inlet pipe, and the upper part of the inner cavity of the stirring and conveying box is connected to the dehydrator through a mud outlet pipe; The upper and lower inner cavities of the stirring and conveying box are both provided with stirring assemblies, the inner cavity of the stirring and conveying box is slidably connected with a filter press ring driven by a lifting mechanism, the inner cavity of the filter press ring is fixedly connected with a filter press cloth, the inner cavity of the filter press ring is fixedly connected with a plurality of support rods abutting the top of the filter press cloth, and the connection between the plurality of support rods forms an empty groove adapted to the stirring assembly, one side of the filter press ring is fixedly connected with a power box, the inner cavity of the power box is movably connected with two clamping plates through a movable groove, the two clamping plates are respectively fixedly connected to the two sides of the filter press cloth, and the two clamping plates form a sealing groove adapted to the surface of the stirring blade. The inner cavity of the power box is fixedly connected with a double-rod cylinder, one side of the two clamping plates is fixedly connected with a push plate fixedly connected to the two piston rods of the double-rod cylinder, and the surface of the filter press ring is fixedly connected with a plurality of uniformly arranged vibration motors. When in use, the silicon-containing wastewater is input from the mud inlet pipe into the inside of the stirring and conveying box. At this time, the silicon-containing wastewater gradually accumulates from bottom to top, and then the two rotating shafts drive the stirring blades to rotate, and the silicon-containing wastewater is fully stirred and mixed. Then the silicon-containing wastewater gradually accumulates until it rises above the mud outlet pipe. After settling for a period of time, the upper driving motor is stopped, and the upper rotating shaft rotates to the fixed position. The filter press ring gradually descends in the inner cavity of the stirring and conveying box. At this time, due to the thrust of the silicon-containing wastewater, the filter press ring cannot be effectively lowered. At this time, the vibration motor starts to drive the filter press ring to vibrate, and the sewage seeps out through the filter press cloth in the inner cavity, and the silicon-containing wastewater remains below. The strength of the filter press cloth is ensured by the support rod. Then the filter press ring gradually descends to the side of the stirring blade at the bottom of the upper rotating shaft. At this time, the splints are located on both sides of the stirring blade. The double-rod cylinder is started to drive the two push plates to move inward, driving the two splints to clamp on the surface of the stirring blade to form a complete annular filter press. The cloth is then driven by the vibration motor to vibrate the filter cloth continuously. At this time, the sewage inside the silicon-containing wastewater is at the top, and different extraction pipes are controlled by the solenoid valve to be connected with the mud pump to extract the wastewater at different heights. The sewage filtered out can be effectively extracted without extracting too much silicon-containing wastewater. Then the silicon-containing wastewater is output through the mud outlet pipe at the bottom. During the transportation process, the silicon-containing wastewater can be automatically filtered without stopping the stirring, and the silicon-containing wastewater and sewage can be effectively separated preliminarily. The treatment can be carried out without stopping the machine, and the height of the filter press ring can be adjusted at any time, and it will not interfere with the normal stirring work of the stirring component above.

[0006] As a further solution of the present invention: the stirring component includes a rotating shaft rotatably connected to the inner cavity of the stirring and conveying box and driven by a driving motor, the inner cavity of the stirring box is fixedly connected with support rings rotatably connected to the rotating shafts respectively, the surfaces of the rotating shafts are fixedly connected with stirring blades, and two stirring components are provided, and are symmetrically distributed above and below the stirring and conveying box. Through the arrangement of the upper and lower stirring components, a segmented stirring layout is formed when normal stirring can be guaranteed, the upper stirring component can be shut down, and empty grooves adapted to the rotating shaft and the stirring blades are formed between the multiple support rods. When the rotating shaft is rotated to a fixed angle, the filter press ring can be smoothly raised and lowered.

[0007] As a further solution of the present invention: the mud outlet pipe is arranged above the support ring.

[0008] As a further solution of the present invention: the surface of the stirring and conveying box located behind the upper rotating shaft is connected with a plurality of extraction pipes connected to the mud pump. There are multiple extraction pipes, and two of them are controlled by a solenoid valve in a group. Different extraction pipes are controlled by the solenoid valve to be connected to the mud pump, and extraction is performed at positions at different heights. The sewage filtered out can be effectively extracted without extracting too much silicon-containing wastewater.

[0009] As a further solution of the present invention: the lifting mechanism includes an electric hoist fixed on the top of the stirring and conveying box, the transmission end of the electric hoist is fixedly connected to the top of the filter press ring through a pull rope, and the height of the filter press ring in the inner cavity of the stirring and conveying box is adjusted by driving the pull rope to lift and lower the electric hoist.

[0010] As a further solution of the present invention: the ends of the plurality of support rods are fixedly connected with a notch ring sleeved on the surface of the rotating shaft, and the notch ring is movably arranged with the surface of the driving shaft.

[0011] As a further solution of the present invention: the inner cavity of the movable groove is fixedly connected to the surface of the splint through a sealing gasket. Through the setting of the sealing gasket, the splint can be freely rotated to open and close while preventing external silicon-containing wastewater from entering the power box through the movable groove.

[0012] As a further solution of the present invention: the inner cavity of the stirring and conveying box is separated by a filter press ring into a silicon-containing wastewater cavity below and a sewage cavity above.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The present invention can automatically filter the silicon-containing wastewater without stopping stirring during the transportation process, effectively perform preliminary separation on the silicon-containing wastewater, and can process without stopping the machine. The height of the filter press ring can be adjusted at any time, and it will not interfere with the normal stirring work of the stirring component above.

[0014] In the present invention, the filter press ring gradually descends in the inner cavity of the stirring and conveying box. At this time, due to the thrust of the silicon-containing wastewater, the filter press ring cannot be effectively descended. At this time, the vibration motor is started to drive the filter press ring to vibrate, and the sewage seeps out through the filter press cloth in the inner cavity, and the silicon is retained at the bottom. The strength of the filter press cloth is ensured by the support rod.

[0015] In the present invention, the filter press ring gradually descends to the side of the stirring blade at the bottom of the upper rotating shaft. At this time, the clamping plates are respectively located on both sides of the stirring blade. The double-rod cylinder is started to drive the two push plates to move inward, driving the two clamping plates to clamp on the surface of the stirring blade to form a complete annular filter press cloth.

[0016] The present invention controls different extraction pipes to be connected to the mud pump through the solenoid valve, and extracts at positions of different heights, so that the sewage obtained by pressure filtration can be effectively extracted without extracting too much silicon-containing wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a structural cross-sectional view of the present invention; Figure 3 A top view of the structure of the filter press ring of the present invention; Figure 4 This is a schematic diagram of the filter press ring clamping plate of the present invention in an open state; Figure 5 For the present invention Figure 3 A partial enlarged view of point A in the middle.

[0018] In the figure: 1. stirring and conveying box; 2. electric hoist; 3. support ring; 4. driving motor; 5. rotating shaft; 6. stirring blade; 7. mud inlet pipe; 8. mud outlet pipe; 9. pull rope; 10. filter press ring; 11. extraction pipe; 12. filter press cloth; 13. support rod; 14. vibration motor; 15. power box; 16. movable groove; 17. sealing rubber pad; 19. double-rod cylinder; 20. clamping plate; 21. push plate; 22. sealing groove. DETAILED DESCRIPTION

[0019] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0020] See also Figure 1-5 , the present invention provides a technical solution: a treatment device for polysilicon production wastewater, comprising a wastewater storage tank, a silicon-containing wastewater screw pump, a PAM dosing unit and a dehydrator, wherein the wastewater storage tank and the dehydrator are connected via a silicon-containing wastewater conveying component; The silicon-containing wastewater conveying assembly comprises a stirring and conveying box 1, the bottom of the inner cavity of the stirring and conveying box 1 is connected to the wastewater storage tank through a mud inlet pipe 7, and the top of the inner cavity of the stirring and conveying box 1 is connected to the dehydrator through a mud outlet pipe 8; The upper and lower inner cavities of the stirring and conveying box body 1 are both provided with stirring components. The inner cavity of the stirring and conveying box body 1 is slidably connected with a filter press ring 10 driven by a lifting mechanism. The inner cavity of the filter press ring 10 is fixedly connected with a filter press cloth 12. The inner cavity of the filter press ring 10 is fixedly connected with a plurality of support rods 13 abutting against the top of the filter press cloth 12. The connection between the plurality of support rods 13 forms an empty groove adapted to the stirring component. One side of the filter press ring 10 is fixedly connected with a power box 15. The inner cavity of the power box 15 is movably connected with two clamping plates 20 through a movable groove 16. The two clamping plates 20 are respectively fixedly connected to the two sides of the filter press cloth 12. The two clamping plates 20 form a sealing groove 22 adapted to the surface of the stirring blade 6. The inner cavity of the box 15 is fixedly connected with a double-rod cylinder 19, and one side of the two clamping plates 20 is fixedly connected with a push plate 21 fixedly connected to the two piston rods of the double-rod cylinder 19. The surface of the filter press ring 10 is fixedly connected with a plurality of uniformly arranged vibration motors 14. When in use, the silicon-containing wastewater is input from the mud inlet pipe 7 into the inside of the stirring and conveying box 1. At this time, the silicon-containing wastewater gradually accumulates from bottom to top, and then the two rotating shafts 5 drive the stirring blades 6 to rotate to fully stir and mix the silicon-containing wastewater. Then the silicon-containing wastewater gradually accumulates until it rises above the mud outlet pipe 8. After settling for a period of time, the upper drive motor 4 is stopped, and the upper rotating shaft 5 rotates to a fixed angle and stops. The filter press ring 10 stops rotating, and then the pull rope 9 is lowered by the electric hoist 2, and the filter press ring 10 gradually descends in the inner cavity of the stirring and conveying box 1. At this time, due to the thrust of the silicon-containing wastewater, the filter press ring 10 cannot be effectively lowered. At this time, the vibration motor is started to drive the filter press ring 10 to vibrate, and the sewage seeps out through the filter press cloth 12 in the inner cavity, and the silicon-containing wastewater remains below. The strength of the filter press cloth 12 is ensured by the support rod 13. Then the filter press ring 10 gradually descends to the side of the stirring blade 6 at the bottom of the upper rotating shaft 5. At this time, the clamping plates 20 are respectively located on both sides of the stirring blade 6. The double-rod cylinder 19 is started to drive the two push plates 21 to move inward, driving the two clamping plates 20 to clamp on the surface of the stirring blade 6 to form a The annular complete filter press cloth 12, and then the vibration motor 14 continuously drives the filter press cloth 12 to vibrate. At this time, the sewage inside the silicon-containing wastewater is at the top, and different extraction pipes 11 are controlled by solenoid valves to be connected with the mud pump to extract the sewage at different heights, which can effectively extract the sewage filtered out without extracting too much silicon-containing wastewater. Then the silicon-containing wastewater is output through the mud outlet pipe 8 at the bottom. During the transportation process, the silicon-containing wastewater can be automatically filtered without stopping the stirring, and the silicon-containing wastewater and sewage can be effectively preliminarily separated, and the treatment can be carried out without stopping the machine. The height of the filter press ring 10 can be adjusted at any time, and it will not interfere with the normal stirring work of the stirring component above.

[0021] The stirring assembly includes a rotating shaft 5 rotatably connected to the inner cavity of the stirring and conveying box 1 and driven by a driving motor 4. The inner cavity of the stirring and conveying box 1 is fixedly connected with support rings 3 rotatably connected to the rotating shaft 5 respectively. The surface of the rotating shaft 5 is fixedly connected with stirring blades 6. Two stirring assemblies are provided, and are symmetrically distributed above and below the stirring and conveying box 1. Through the arrangement of the upper and lower stirring assemblies, a segmented stirring layout is formed when normal stirring can be guaranteed. The upper stirring assembly can be shut down, and empty grooves adapted to the rotating shaft 5 and the stirring blades 6 are formed between the multiple support rods 13. When the rotating shaft 5 is rotated to a fixed angle, the filter press ring 10 can be smoothly raised and lowered.

[0022] The mud discharge pipe 8 is arranged above the support ring 3 .

[0023] The surface of the stirring and conveying box 1 located behind the upper rotating shaft 5 is connected with a plurality of extraction pipes 11 connected to the mud pump. There are a plurality of extraction pipes 11, and two of them are controlled by a solenoid valve. Different extraction pipes 11 are controlled by the solenoid valve to be connected to the mud pump, and extraction is performed at positions at different heights. The sewage filtered out can be effectively extracted without extracting too much silicon-containing wastewater.

[0024] The lifting mechanism includes an electric hoist 2 fixed on the top of the stirring and conveying box 1. The transmission end of the electric hoist 2 is fixedly connected to the top of the filter press ring 10 through a pull rope 9. The electric hoist 2 drives the pull rope 9 to rise and fall to adjust the height of the filter press ring 10 in the inner cavity of the stirring and conveying box 1.

[0025] The ends of the plurality of support rods 13 are fixedly connected to a notch ring sleeved on the surface of the rotating shaft 5 , and the notch ring is movably arranged on the surface of the driving shaft.

[0026] The inner cavity of the movable groove 16 is fixedly connected to the surface of the clamping plate 20 through the sealing gasket 17. Through the setting of the sealing gasket 17, the clamping plate 20 can be freely rotated to open and close while preventing external silicon-containing wastewater from entering the power box 15 from the movable groove 16.

[0027] The inner cavity of the stirring and conveying box 1 is separated into a silicon-containing wastewater cavity below and a sewage cavity above by a filter press ring 10 .

[0028] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. Treatment equipment for polysilicon production wastewater, including a wastewater storage tank, a silicon-containing wastewater screw pump, a PAM dosing unit and a dehydrator, characterized in that: The wastewater storage tank and the dehydrator are connected via a silicon-containing wastewater conveying component; The silicon-containing wastewater conveying assembly comprises a stirring and conveying box (1), the bottom of the inner cavity of the stirring and conveying box (1) is connected to the wastewater storage tank via a mud inlet pipe (7), and the top of the inner cavity of the stirring and conveying box (1) is connected to a dewatering machine via a mud outlet pipe (8); The upper and lower inner cavities of the stirring and conveying box (1) are both provided with stirring assemblies. The inner cavity of the stirring and conveying box (1) is slidably connected to a filter press ring (10) driven by a lifting mechanism. The inner cavity of the filter press ring (10) is fixedly connected to a filter press cloth (12). The inner cavity of the filter press ring (10) is fixedly connected to a plurality of support rods (13) abutting against the top of the filter press cloth (12). The connection between the plurality of support rods (13) forms an empty groove adapted to the stirring assembly. One side of the filter press ring (10) is fixedly connected to a power box (15). The inner cavity of the power box (15) is fixedly connected to a filter press cloth (12). The cavity is movably connected to two clamping plates (20) through a movable groove (16); the two clamping plates (20) are respectively fixedly connected to the two sides of the filter press cloth (12); the two clamping plates (20) form a sealing groove (22) adapted to the surface of the stirring blade (6); the inner cavity of the power box (15) is fixedly connected to a double-rod cylinder (19); one side of the two clamping plates (20) is fixedly connected to a push plate (21) fixedly connected to the two piston rods of the double-rod cylinder (19); and the surface of the filter press ring (10) is fixedly connected to a plurality of uniformly arranged vibration motors (14).

2. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The stirring assembly comprises a rotating shaft (5) rotatably connected to the inner cavity of the stirring and conveying box (1) and driven by a driving motor (4); the inner cavity of the stirring and conveying box (1) is fixedly connected with support rings (3) rotatably connected to the rotating shafts (5); the surfaces of the rotating shafts (5) are fixedly connected with stirring blades (6); two stirring assemblies are provided and are symmetrically distributed above and below the stirring and conveying box (1).

3. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The mud outlet pipe (8) is arranged above the support ring (3).

4. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The surface of the stirring and conveying box (1) located behind the upper rotating shaft (5) is connected to a plurality of extraction pipes (11) connected to the mud pump. A plurality of extraction pipes (11) are provided, and two by two are controlled in a group by a solenoid valve.

5. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The lifting mechanism comprises an electric hoist (2) fixed on the top of the stirring and conveying box (1), and the transmission end of the electric hoist (2) is fixedly connected to the top of the filter press ring (10) via a pull rope (9).

6. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The ends of the plurality of support rods (13) are fixedly connected to a notch ring sleeved on the surface of the rotating shaft (5), and the notch ring is movably arranged on the surface of the driving shaft.

7. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The inner cavity of the movable groove (16) is fixedly connected to the surface of the clamping plate (20) via a sealing rubber pad (17).

8. The polysilicon production wastewater treatment equipment according to claim 1, characterized in that: The inner cavity of the stirring and conveying box (1) is separated by a filter press ring (10) into a silicon-containing wastewater cavity at the bottom and a sewage cavity at the top.

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