Wastewater multi-stage treatment device and process for water-based varnish production

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a wastewater multi-stage treatment device and process for water varnish production, the wastewater multi-stage treatment device comprises a first-stage sedimentation tank and a second-stage sedimentation tank located below the first-stage sedimentation tank, and dewatering structures for conveying bottom sludge upwards and extruding and dewatering are arranged in the first-stage sedimentation tank and the second-stage sedimentation tank; one side of the dewatering structure communicates with the deslagging structure, and the outer side of the dewatering structure is sleeved with a cleaning assembly for cleaning the dewatering structure. According to the dewatering structure, the dewatering work of the sludge can be completed in the upward conveying process of the sludge, the dewatering mode is simple and rapid, more importantly, water discharged through extrusion can conveniently and rapidly fall back into the corresponding first-stage sedimentation tank and second-stage sedimentation tank, and the dewatering efficiency is improved. Therefore, a water delivery structure is prevented from being additionally designed to deliver the extruded and drained water back to the sedimentation tank.

Description

Technical Field

[0001] The present invention relates to the technical field of wastewater treatment, and particularly relates to a multi-stage treatment device and process for wastewater in waterborne varnish production. Background Art

[0002] During the production process of waterborne varnish, a large amount of wastewater with complex components is generated, which contains various pollutants such as resin, pigment, solvent, surfactant, etc. If these wastewaters are directly discharged without effective treatment, it will inevitably cause serious harm to the ecological environment.

[0003] Currently, for the treatment of such wastewaters, most of them are to add the wastewater into a sedimentation tank and add a flocculant for flocculation precipitation, and then discharge the bottom sludge for dehydration and drying to complete the rapid treatment of the wastewater; however, a single sedimentation tank is difficult to ensure the sufficiency of precipitation, and the wastewater generated during the sludge dehydration process also needs to be transported back to the sedimentation tank through a water supply device, which further reduces the convenience of wastewater treatment and increases the energy consumption of the water purification process. Summary of the Invention

[0004] Aiming at the problems in the prior art, the present invention provides a multi-stage treatment device and process for wastewater in waterborne varnish production to solve the problems that a single sedimentation tank is difficult to fully precipitate and the wastewater generated by sludge dehydration is not convenient to be transported back to the sedimentation tank.

[0005] The technical solution adopted by the present invention to solve its technical problems is a multi-stage treatment device for wastewater in waterborne varnish production, including a primary sedimentation tank and a secondary sedimentation tank located below the primary sedimentation tank. Both the primary sedimentation tank and the secondary sedimentation tank are provided with a dehydration structure for upwardly transporting and squeezing and dehydrating the bottom sludge. One side of the dehydration structure is communicated with a slag discharge structure, and a cleaning component for cleaning the dehydration structure is sleeved outside the dehydration structure.

[0006] Preferably, both the bottom of the primary sedimentation tank and the secondary sedimentation tank are communicated with an aggregate tank with an upward opening. The dehydration structure includes a conveying cylinder vertically and fixedly connected to the bottom of the aggregate tank. A slag inlet is opened at the bottom of the conveying cylinder. A sealing cylinder for closing the slag inlet is sleeved at the bottom of the conveying cylinder. The top outer side of the sealing cylinder is connected with a movable plate that is hermetically and slidably connected to the bottom of the aggregate tank. A support spring is connected between the lower surface of the movable plate and the bottom of the aggregate tank. The upper end of the conveying cylinder is communicated with a conical tube with a smaller upper part and a larger lower part. The conical tube is provided with filtering holes. Vertical sleeves are provided in both the primary sedimentation tank and the secondary sedimentation tank. The sleeves pass through the aggregate tank, the conveying cylinder, and the conical tube and are rotatably connected to the aggregate tank. A spiral plate connected to the sleeve is provided in the conveying cylinder, and a conical spiral blade connected to the sleeve is provided in the conical tube. A driving mechanism for driving the sleeve to rotate is installed at the bottom of the secondary sedimentation tank.

[0007] Preferably, the cleaning component is sleeved outside the conical tube. The cleaning component includes several groups of movable pieces arranged around the conical tube. A cleaning needle corresponding to the filter holes is connected to the inner side surface of the movable piece. A spring is connected between adjacent movable pieces. After adjacent movable pieces are squeezed and approached, a conical pipe fitting with a larger upper part and a smaller lower part is formed. A conical extrusion pipe with a larger upper part and a smaller lower part is sleeved outside the conical pipe fitting. The outside of the conical extrusion pipe is connected to a movable plate through a vertically arranged pull rod. The slag discharge structure includes a discharge bin communicated with the upper end of the conical tube. A positioning chute corresponding to the movable piece is arranged on the lower surface of the discharge bin. A positioning slider is connected to the upper end of the movable piece. The positioning slider is slidably connected with the positioning chute.

[0008] Preferably, the driving mechanism includes a driving motor fixedly installed at the bottom of the secondary sedimentation tank. The output end of the driving motor is connected with a vertical driving shaft. The driving shaft passes through the sleeve and is rotationally connected with the sleeve. The sleeve and the driving shaft are driven by an opening and closing component.

[0009] Preferably, the opening and closing component includes a driving ratchet fixedly connected to the upper end of the sleeve with the tooth surface facing upward. A driven ratchet with the tooth surface facing downward is vertically slidably connected to the driving shaft. An annular positioning groove is arranged outside the driven ratchet. The outside of the annular positioning groove is rotationally connected with a support plate through the annular positioning groove. A vertically arranged ejector rod is fixedly connected to the side surface of the conical extrusion pipe. The upper end of the ejector rod is in pressing contact with the lower surface of the support plate.

[0010] Preferably, the slag discharge structure includes a discharge shell communicated with one side of the discharge bin. The sleeve passes through the discharge bin and is rotationally connected with the discharge bin. The lower ends of the discharge shells are commonly communicated to a slag discharge pipe.

[0011] Preferably, a heating plate is installed at the inner bottom of the discharge shell. An exhaust window is detachably connected to the upper part of the discharge shell.

[0012] Preferably, the bottoms of both the primary sedimentation tank and the secondary sedimentation tank are funnel-shaped structures. The lower ends of the funnel-shaped structures are communicated with an aggregate tank.

[0013] Preferably, a tension spring is connected between the side of the positioning slider away from the driving shaft and the positioning chute.

[0014] A multi-stage treatment process for wastewater in waterborne varnish production uses the above-mentioned multi-stage treatment device for wastewater in waterborne varnish production, and specifically includes the following steps:

[0015] Step 1: Transport the wastewater to the primary sedimentation tank and add a flocculant to the primary sedimentation tank.

[0016] Step 2: After the flocculation in the primary sedimentation tank is completed, the dewatering structure conveys the sludge at the bottom of the primary sedimentation tank upward and squeezes it for dewatering. The water body squeezed out falls back into the primary sedimentation tank, and the dewatered waste residue is discharged through the slag discharging structure;

[0017] Step 3: After the dewatering work of the dewatering structure is completed, the cleaning component cleans the dewatering structure, and at the same time conveys the water body that has completed sedimentation in the primary sedimentation tank into the secondary sedimentation tank, and adds new wastewater to the primary sedimentation tank;

[0018] Step 4: While adding a flocculant to the primary sedimentation tank, add a flocculant to the secondary sedimentation tank again;

[0019] Step 5: After the sedimentation in the primary sedimentation tank is completed, the dewatering structure conveys the sludge at the bottoms of the primary sedimentation tank and the secondary sedimentation tank upward and squeezes out the water. The water body squeezed out falls back into the corresponding primary sedimentation tank and secondary sedimentation tank, and the dewatered waste residue is discharged through the slag discharging structure.

[0020] Advantages of the present invention:

[0021] (1) For the multi-stage wastewater treatment device and process for waterborne varnish production described in the present invention, the secondary sedimentation tank serves as a supplement to the primary sedimentation tank. When the sedimentation in the primary sedimentation tank is sufficient, secondary sedimentation work can be carried out to improve the wastewater sedimentation effect; during the process of conveying the sludge upward by the dewatering structure, the dewatering work of the sludge can be completed. The dewatering method is simple and fast. More importantly, it can facilitate the water body squeezed out to quickly fall back into the corresponding sedimentation tank, thereby avoiding the need to additionally design a water conveyance structure to convey the water body of the squeezed-out water back to the sedimentation tank.

[0022] (2) For the multi-stage wastewater treatment device and process for waterborne varnish production described in the present invention, when the driving mechanism drives the sleeve to rotate, the spiral plate and the conical spiral blade can be driven to rotate. The spiral plate rotates to convey the sludge at the lower end of the conveying cylinder upward into the conical tube. Relying on the rotation of the conical spiral blade, the sludge can be driven to move further upward. And because the pitch and diameter of the conical spiral blade gradually decrease, the sludge is squeezed and dewatered when being conveyed in the conical spiral blade. The water body squeezed out is discharged through the filter holes and falls back into the corresponding primary sedimentation tank and secondary sedimentation tank; the waste residue after extrusion and dewatering will enter the slag discharging structure and be discharged;

[0023] (3) For the multi-stage treatment device and process for wastewater in the production of waterborne varnish according to the present invention, as the movable plate moves downward, it drives the pull rod to move downward, thereby driving the conical extrusion tube to move downward. After the conical extrusion tube moves downward, the movable piece moves outward by relying on the spring reset, and the cleaning needle is separated from the filter hole. After the sludge on the movable plate is discharged, the movable plate is reset by relying on the support spring and pushes the pull rod upward. The upward movement of the pull rod drives the conical extrusion tube to move upward, thereby squeezing all the movable pieces to contract inward. After the movable pieces contract inward, they drive the cleaning needle to insert into the filter hole, and push the sludge blocked in the filter hole back into the conical tube to complete the cleaning of the filter hole. At the same time, when the cleaning needle inserts into the filter hole, it can also reduce the situation where wastewater splashes into the conical tube through the filter hole. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0025] Figure 1 is an axonometric view of the multi-stage treatment device for wastewater in the production of waterborne varnish according to the present invention;

[0026] Figure 2 is a partial sectional view of the multi-stage treatment device for wastewater in the production of waterborne varnish according to the present invention;

[0027] Figure 3 is Figure 2 an enlarged view of area A of

[0028] Figure 4 is Figure 2 an enlarged schematic view of area B of

[0029] Figure 5 is an axonometric view of the conveying cylinder according to the present invention;

[0030] Figure 6 is an axonometric view of the spiral plate according to the present invention;

[0031] Figure 7 is an axonometric view of the movable piece according to the present invention;

[0032] Figure 8 is an axonometric view of the conical extrusion tube according to the present invention;

[0033] In the figure: 1. Primary sedimentation tank; 2. Secondary sedimentation tank; 3. Support frame; 4. Aggregate trough; 5. Conveyor tube; 6. Slag inlet; 7. Sealing tube; 8. Movable plate; 9. Support spring; 10. Conical tube; 11. Filter holes; 12. Sleeve; 13. Spiral plate; 14. Conical spiral blade; 15. Movable piece; 16. Cleaning needle; 17. Spring; 18. Conical extrusion tube; 19. Pull rod; 20. Discharge bin; 21. Positioning chute; 22. Positioning slider; 23. Driving motor; 24. Driving shaft; 25. Driving ratchet; 26. Driven ratchet; 27. Positioning convex block; 28. Positioning groove; 29. Annular positioning groove; 30. Support plate; 31. Jacking rod; 32. Discharge housing; 33. Slag discharge pipe; 34. Air exhaust window. Detailed implementation manners

[0034] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0035] As an embodiment of the present invention, as Figures 1 to 8 shown, a multi-stage wastewater treatment device for the production of waterborne varnish according to the present invention includes a primary sedimentation tank 1 and a secondary sedimentation tank 2 located below the primary sedimentation tank 1. A dehydration structure for conveying and squeezing and dehydrating the bottom sludge upward is provided in both the primary sedimentation tank 1 and the secondary sedimentation tank 2. One side of the dehydration structure is communicated with a slag discharge structure, and a cleaning component for cleaning the dehydration structure is sleeved outside the dehydration structure.

[0036] During use, the wastewater can be transported to the primary sedimentation tank 1, and a flocculant is added to the primary sedimentation tank 1; after flocculation is completed in the primary sedimentation tank 1, the sludge at the bottom of the primary sedimentation tank 1 is transported upward and squeezed for dehydration by means of a dehydration structure, the water body squeezed out is returned to the primary sedimentation tank 1, and the dehydrated waste residue is discharged through a slag discharge structure; after the dehydration work of the dehydration structure is completed, the dehydration structure is cleaned by a cleaning component, and at the same time, the water body that has completed sedimentation in the primary sedimentation tank 1 is transported to the secondary sedimentation tank 2, and new wastewater is added to the primary sedimentation tank 1; among them, while adding a flocculant to the primary sedimentation tank 1, a flocculant needs to be added to the secondary sedimentation tank 2 again; after sedimentation is completed in the primary sedimentation tank 1, the sludge at the bottoms of the primary sedimentation tank 1 and the secondary sedimentation tank 2 is transported upward and squeezed for drainage by means of the dehydration structure, the water body squeezed out is returned to the corresponding primary sedimentation tank 1 and secondary sedimentation tank 2, and the dehydrated waste residue is discharged through the slag discharge structure. The secondary sedimentation tank 2 serves as a supplement to the primary sedimentation tank 1 and can perform secondary sedimentation when the primary sedimentation tank 1 has sufficient sedimentation, thereby improving the sedimentation effect of the wastewater. The sludge can be dehydrated during the process of the dehydration structure transporting the sludge upward. The dehydration method is simple and fast. More importantly, it can facilitate the water body squeezed out to quickly return to the corresponding sedimentation tank, thereby avoiding the need to additionally design a water conveyance structure to transport the water body of the squeezed drainage back to the sedimentation tank. It should be noted that a support frame 3 is connected between the primary sedimentation tank 1 and the secondary sedimentation tank 2 to ensure the stability between the primary sedimentation tank 1 and the secondary sedimentation tank 2.

[0037] To ensure the dehydration effect of the dehydration structure, as an embodiment of the present invention, an aggregate tank 4 with an upward opening is connected to the bottoms of both the primary sedimentation tank 1 and the secondary sedimentation tank 2 of the present invention. The dehydration structure includes a conveying cylinder 5 vertically and fixedly connected to the bottom of the aggregate tank 4. A slag inlet 6 is opened at the bottom of the conveying cylinder 5. A sealing cylinder 7 that closes the slag inlet 6 is sleeved on the bottom of the conveying cylinder 5. The outer side of the top of the sealing cylinder 7 is connected with a movable plate 8 that is hermetically and slidably connected to the aggregate tank 4. A support spring 9 is connected between the lower surface of the movable plate 8 and the bottom of the aggregate tank 4. The upper end of the conveying cylinder 5 is communicated with a conical pipe 10 that is small at the top and large at the bottom. Filter holes 11 are provided on the conical pipe 10. Vertical sleeves 12 are provided in both the primary sedimentation tank 1 and the secondary sedimentation tank 2. The sleeve 12 passes through the aggregate tank 4, the conveying cylinder 5, and the conical pipe 10 and is rotatably connected to the aggregate tank 4. A spiral plate 13 connected to the sleeve 12 is provided in the conveying cylinder 5. A conical spiral blade 14 connected to the sleeve 12 is provided in the conical pipe 10. A driving mechanism for driving the sleeve 12 to rotate is installed at the bottom of the secondary sedimentation tank 2.

[0038] During use, the sludge deposited at the bottom of the primary sedimentation tank 1 and the secondary sedimentation tank 2 will accumulate in the aggregate tank 4. Due to the relatively large density of the sludge, the pressure on the movable plate 8 increases. As the amount of sludge accumulated on the movable plate 8 increases, the movable plate 8 gradually moves downward. When the movable plate 8 drives the sealing cylinder 7 to move below the slag inlet 6, the sludge accumulated in the aggregate tank 4 will enter the conveying cylinder 5 through the slag inlet 6; when the driving mechanism drives the sleeve 12 to rotate, it can drive the spiral plate 13 and the conical spiral blade 14 to rotate. The spiral plate 13 rotates to convey the sludge at the lower end of the conveying cylinder 5 upward into the conical tube 10. Relying on the rotation of the conical spiral blade 14, the sludge can be driven to move further upward. And because the pitch and diameter of the conical spiral blade 14 gradually decrease, the sludge is squeezed and dehydrated when being conveyed in the conical spiral blade 14. The squeezed-out water body is discharged through the filter holes 11 and falls back to the corresponding primary sedimentation tank 1 and secondary sedimentation tank 2; the waste residue after squeezing and dehydration will enter the slag discharge structure and be discharged.

[0039] In order to reduce the blockage of the dehydration structure to ensure the dehydration effect of the dehydration structure, as an embodiment of the present invention, the cleaning component of the present invention is sleeved outside the conical tube 10. The cleaning component includes a plurality of groups of movable pieces 15 arranged around the conical tube 10. The inner side surface of the movable piece 15 is connected with a cleaning needle 16 corresponding to the filter holes 11. A spring 17 is connected between adjacent movable pieces 15. After adjacent movable pieces 15 are squeezed and close to each other, a conical pipe fitting with a larger upper part and a smaller lower part is formed. The outside of the conical pipe fitting is sleeved with a conical extrusion pipe 18 with a larger upper part and a smaller lower part. The outside of the conical extrusion pipe 18 is connected with the movable plate 8 through a vertically arranged pull rod 19. The slag discharge structure includes a discharge bin 20 communicated with the upper end of the conical tube 10. The lower surface of the discharge bin 20 is provided with a positioning sliding groove 21 corresponding to the movable piece 15. The upper end of the movable piece 15 is connected with a positioning slider 22. The positioning slider 22 is slidably connected with the positioning sliding groove 21.

[0040] During use, as the movable plate 8 moves downward, it will drive the pull rod 19 to move downward, thereby driving the conical extrusion pipe 18 to move downward; after the conical extrusion pipe 18 moves downward, the movable piece 15 relies on the spring 17 to reset and move outward, and the cleaning needle 16 is separated from the filter hole 11; after the sludge on the movable plate 8 is discharged, the movable plate 8 relies on the support spring 9 to reset and pushes the pull rod 19 upward. The upward movement of the pull rod 19 drives the conical extrusion pipe 18 to move upward, thereby squeezing all the movable pieces 15 to contract inward. After the movable piece 15 contracts inward, it drives the cleaning needle 16 to insert into the filter hole 11, and pushes the sludge blocked in the filter hole 11 back into the conical tube 10 to complete the cleaning of the filter hole 11; at the same time, when the cleaning needle 16 inserts into the filter hole 11, it can also reduce the situation that the waste water splashes into the conical tube 10 through the filter hole 11.

[0041] In order to facilitate the driving structure to dewater sludge in the primary sedimentation tank 1 and the secondary sedimentation tank 2, as an embodiment of the present invention, the driving mechanism of the present invention includes a driving motor 23 fixedly installed at the bottom of the secondary sedimentation tank 2, and the output end of the driving motor 23 is connected to a vertical driving shaft 24, and the driving shaft 24 passes through the sleeve 12 and is rotatably connected to the sleeve 12, and the sleeve 12 and the driving shaft 24 are transmitted through an opening and closing assembly.

[0042] When in use, after the opening and closing component driving sleeve 12 and the driving shaft 24 are able to transmit, the driving motor 23 can be used to drive the driving shaft 24 to rotate, thereby driving the sleeve 12 to rotate. The rotation of the sleeve 12 can drive the spiral plate 13 and the conical spiral blade 14 to rotate, thereby driving the dehydration structure to realize the sludge transportation and dehydration of the primary sedimentation tank 1 and the secondary sedimentation tank 2.

[0043] In order to facilitate the opening and closing assembly to automatically transmit the sleeve 12 and the drive shaft 24, as an embodiment of the present invention, the opening and closing assembly of the present invention includes a driving ratchet 25 fixedly connected to the upper end of the sleeve 12 with the tooth surface facing upward, and a driven ratchet 26 with the tooth surface facing downward is vertically slidably connected to the drive shaft 24, and an annular positioning groove 29 is provided on the outer side of the driven ratchet 26, and a support plate 30 is rotatably connected to the outer side of the annular positioning groove 29 through the annular positioning groove 29, and a vertically arranged push rod 31 is fixedly connected to the side of the conical extrusion tube 18, and the upper end of the push rod 31 is in extrusion contact with the lower surface of the support plate 30.

[0044] When in use, as the movable plate 8 moves downward, the pull rod 19 will be driven downward, thereby driving the conical extrusion tube 18 downward. When the conical tube 10 moves downward, the push rod 31 will be driven downward, so that the driven ratchet 26 moves downward. After the driven ratchet 26 moves downward, it meshes with the driving ratchet 25. At this time, the drive shaft 24 and the sleeve 12 realize transmission. Then, the drive motor 23 is turned on to drive the sleeve 12 to rotate, thereby driving the dewatering structure to transport and dewater the sludge. After the sludge on the movable plate 8 is discharged, the movable plate 8 is turned on. The plate 8 is reset by the support spring 9, and pushes the pull rod 19 upward. The pull rod 19 moves upward to drive the conical extrusion tube 18 upward, thereby driving the push rod 31 upward, so that the driven ratchet 26 moves upward and disengages from the driving ratchet 25, disconnecting the transmission of the drive shaft 24 and the sleeve 12; after the drive shaft 24 and the sleeve 12 are disconnected, the resistance to the rotation of the drive shaft 24 can be effectively reduced, and when the sedimentation tank corresponding to the sleeve 12 does not need to clean the sludge, the dehydration structure is still transmitted with the drive shaft 24, thereby increasing the resistance to the operation of the drive shaft 24. It should be pointed out that in order to ensure the sliding effect of the driven ratchet 26 and the drive shaft 24, the inner side of the driven ratchet 26 is connected to the positioning protrusion 27, and the drive shaft 24 is provided with a positioning groove 28 that is slidably connected to the positioning protrusion 27.

[0045] To facilitate the slag discharge of the slag discharge structure, as an embodiment of the present invention, the slag discharge structure of the present invention includes a discharge shell 32 connected to one side of the discharge bin 20. The sleeve 12 passes through the discharge bin 20 and is rotatably connected to the discharge bin 20. The lower ends of the discharge shells 32 are jointly connected to the slag discharge pipe 33.

[0046] During use, the sludge continuously moves upward and is squeezed and dewatered as the dewatering structure works. The squeezed and discharged water body is discharged through the filter holes 11 and falls back to the corresponding primary sedimentation tank 1 and secondary sedimentation tank 2. The waste residue after squeezing and dewatering enters the discharge bin 20 of the slag discharge structure and is discharged to the slag discharge pipe 33 through the discharge shell 32. A treatment device can be connected to the lower end of the slag discharge pipe 33 for subsequent treatment.

[0047] To facilitate the further drying treatment of the dewatered waste residue, as an embodiment of the present invention, a heating plate is installed at the inner bottom of the discharge shell 32, and an exhaust window 34 is detachably connected to the upper part of the discharge shell 32.

[0048] During use, after the waste residue enters the discharge shell 32 through the discharge bin 20, it moves downward along the bottom of the discharge shell 32. At this time, the heating plate heats and dries the waste residue, and the steam can be discharged through the exhaust window 34. The dried waste residue enters the slag discharge pipe 33. It should be noted that to ensure environmental protection, an exhaust gas treatment device generally needs to be connected to the exhaust window 34 to avoid the pollution of the environment by harmful substances in the steam.

[0049] To facilitate the aggregation of the sludge box aggregate troughs 4 at the bottoms of the primary sedimentation tank 1 and the secondary sedimentation tank 2, as an embodiment of the present invention, the bottoms of the primary sedimentation tank 1 and the secondary sedimentation tank 2 of the present invention are both funnel-shaped structures, and the lower ends of the funnel-shaped structures are connected to the aggregate trough 4.

[0050] To further improve the convenience of the reset of the movable plate 8, a tension spring is connected between the side of the positioning slider 22 away from the drive shaft 24 and the positioning chute 21 of the present invention. Through the design of the tension spring, it can further facilitate the downward movement of the conical extrusion tube 18, the outward movement of the movable piece 15, and the separation of the cleaning needle 16 from the filter hole 11.

[0051] The present invention also provides a multi-stage treatment process for wastewater used in the production of water-based varnish. The above-mentioned multi-stage treatment device for wastewater used in the production of water-based varnish specifically includes the following steps:

[0052] Step 1: Transport the wastewater to the primary sedimentation tank 1 and add a flocculant to the primary sedimentation tank 1;

[0053] Step 2: After the flocculation in the primary sedimentation tank 1 is completed, the dewatering structure transports the sludge at the bottom of the primary sedimentation tank 1 upward and squeezes and dewater it. The squeezed and discharged water body falls back to the primary sedimentation tank 1, and the dewatered waste residue is discharged through the slag discharge structure;

[0054] Step 3: After the dehydration of the dehydration structure is completed, the cleaning component cleans the dehydration structure, and at the same time conveys the water body that has completed precipitation in the first sedimentation tank 1 to the second sedimentation tank 2, and adds new wastewater to the first sedimentation tank 1.

[0055] Step 4: While adding a flocculant to the first sedimentation tank 1, add a flocculant to the second sedimentation tank 2 again.

[0056] Step 5: After the precipitation in the first sedimentation tank 1 is completed, the dehydration structure conveys the sludge at the bottom of the first sedimentation tank 1 and the second sedimentation tank 2 upward and squeezes out the water. The squeezed-out water body falls back into the corresponding first sedimentation tank 1 and the second sedimentation tank 2, and the dehydrated waste residue is discharged through the slag discharge structure.

[0057] When the present invention is in use, wastewater is conveyed to the first sedimentation tank 1, and a flocculant is added to the first sedimentation tank 1; after the flocculation in the first sedimentation tank 1 is completed, the sludge in the first sedimentation tank 1 will accumulate in the aggregate tank 4. As the amount of sludge accumulated on the movable plate 8 increases, the movable plate 8 gradually moves downward. When the movable plate 8 drives the sealing cylinder 7 to move below the slag inlet 6, the sludge accumulated in the aggregate tank 4 will enter the conveying cylinder 5 through the slag inlet 6; as the movable plate 8 moves downward, it will drive the pull rod 19 to move downward, thereby driving the conical extrusion tube 18 to move downward. While the conical tube 10 moves downward, it will drive the ejector rod 31 to move downward, so that the driven ratchet wheel 26 moves downward. After the driven ratchet wheel 26 moves downward, it meshes with the driving ratchet wheel 25. At this time, the driving shaft 24 and the sleeve 12 achieve transmission; the driving motor 23 drives the driving shaft 24 to rotate, thereby driving the sleeve 12 to rotate. Relying on the rotation of the sleeve 12, the spiral plate 13 and the conical spiral blade 14 can be driven to rotate, so as to drive the dehydration structure to realize the sludge conveying and dehydration work of the first sedimentation tank 1; the waste residue after extrusion dehydration will enter the discharge bin 20 of the slag discharge structure and be discharged to the slag discharge pipe 33 through the discharge shell 32. A treatment device can be connected to the lower end of the slag discharge pipe 33 for subsequent treatment; the squeezed-out water body is discharged through the filter holes 11 and falls back into the first sedimentation tank 1; after the sludge on the movable plate 8 is discharged, the movable plate 8 is reset by the support spring 9 and pushes the pull rod 19 upward. The upward movement of the pull rod 19 drives the conical extrusion tube 18 to move upward, thereby squeezing all the movable pieces 15 to contract inward. After the movable pieces 15 contract inward, the cleaning needles 16 are driven to insert into the filter holes 11, and the sludge blocked in the filter holes 11 is pushed back into the conical tube 10, so as to complete the cleaning of the filter holes 11.

[0058] Afterwards, the water body sedimented in the primary sedimentation tank 1 is conveyed to the secondary sedimentation tank 2, and new wastewater is added to the primary sedimentation tank 1. Among them, while adding a flocculant to the primary sedimentation tank 1, it is necessary to add the flocculant again to the secondary sedimentation tank 2. After the primary sedimentation tank 1 finishes sedimenting again, the sludge at the bottom of the primary sedimentation tank 1 and the secondary sedimentation tank 2 can be conveyed upward and extruded to drain water by means of a dewatering structure. The water body extruded and discharged falls back to the corresponding primary sedimentation tank 1 and secondary sedimentation tank 2, and the dewatered waste residue is discharged through a slag discharging structure.

[0059] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage treatment device for wastewater from water-based varnish production, characterized in that: The invention comprises a primary sedimentation tank (1) and a secondary sedimentation tank (2) located below the primary sedimentation tank (1). The primary sedimentation tank (1) and the secondary sedimentation tank (2) are both provided with a dewatering structure for conveying bottom sludge upward and squeezing and dehydrating it. One side of the dewatering structure is connected to a slag discharge structure. The outer side of the dewatering structure is provided with a cleaning component for cleaning the dewatering structure.

2. A multi-stage treatment device for wastewater from water-based varnish production according to claim 1, characterized in that: The bottoms of the primary sedimentation tank (1) and the secondary sedimentation tank (2) are both connected to a collection tank (4) with an opening facing upwards. The dehydration structure comprises a conveying cylinder (5) vertically fixedly connected to the bottom of the collection tank (4). The bottom of the conveying cylinder (5) is provided with a slag inlet (6). The bottom of the conveying cylinder (5) is sleeved with a sealing cylinder (7) for sealing the slag inlet (6). The top outer side of the sealing cylinder (7) is connected to a movable plate (8) which is sealingly and slidably connected to the collection tank (4). A supporting spring (9) is connected between the lower surface of the movable plate (8) and the bottom of the collection tank (4). The upper end of the conveying cylinder (5) is connected to an upper A tapered tube (10) with a small top and a large bottom is provided, wherein a filter hole (11) is provided on the tapered tube (10), a vertical sleeve (12) is provided in each of the primary sedimentation tank (1) and the secondary sedimentation tank (2), wherein the sleeve (12) passes through a collection tank (4), a conveying cylinder (5) and the tapered tube (10) and is rotatably connected to the collection tank (4), wherein a spiral plate (13) connected to the sleeve (12) is provided in the conveying cylinder (5), wherein a tapered spiral blade (14) connected to the sleeve (12) is provided in the tapered tube (10), and wherein a driving mechanism for driving the sleeve (12) to rotate is installed at the bottom of the secondary sedimentation tank (2).

3. A multi-stage treatment device for wastewater from water-based varnish production according to claim 2, characterized in that: The cleaning assembly is sleeved on the outer side of the conical tube (10), and the cleaning assembly includes a plurality of groups of movable sheets (15) arranged around the conical tube (10). The inner side surface of the movable sheet (15) is connected with a cleaning needle (16) corresponding to the filter hole (11). A spring (17) is connected between adjacent movable sheets (15). Adjacent movable sheets (15) are squeezed close to form a conical tube fitting with a larger upper part and a smaller lower part. The outer side of the conical tube fitting is sleeved with a conical extrusion tube (18) with a larger upper part and a smaller lower part. The outer side of the conical extrusion tube (18) is connected to the movable plate (8) through a vertically arranged pull rod (19). The slag discharge structure includes a discharge bin (20) connected to the upper end of the conical tube (10). The lower surface of the discharge bin (20) is provided with a positioning slide groove (21) corresponding to the movable sheet (15). The upper end of the movable sheet (15) is connected with a positioning slider (22), and the positioning slider (22) is slidably connected to the positioning slide groove (21).

4. A multi-stage treatment device for wastewater from water-based varnish production according to claim 3, characterized in that: The driving mechanism comprises a driving motor (23) fixedly mounted at the bottom of the secondary sedimentation tank (2); the output end of the driving motor (23) is connected to a vertical driving shaft (24); the driving shaft (24) passes through a sleeve (12) and is rotationally connected to the sleeve (12); the sleeve (12) and the driving shaft (24) are transmitted via an opening and closing assembly.

5. A multi-stage treatment device for wastewater from water-based varnish production according to claim 4, characterized in that: The opening and closing assembly comprises a driving ratchet (25) fixedly connected to the upper end of the sleeve (12) and with its tooth surface facing upward, a driven ratchet (26) with its tooth surface facing downward is vertically slidably connected to the driving shaft (24), an annular positioning groove (29) is provided on the outer side of the driven ratchet (26), a support plate (30) is rotatably connected to the outer side of the annular positioning groove (29) through the annular positioning groove (29), and a vertically arranged push rod (31) is fixedly connected to the side of the conical extrusion tube (18), and the upper end of the push rod (31) is in extrusion contact with the lower surface of the support plate (30).

6. A multi-stage treatment device for wastewater from water-based varnish production according to claim 5, characterized in that: The slag discharge structure comprises a discharge shell (32) connected to one side of the silo, the sleeve (12) passes through the discharge silo (20) and is rotatably connected to the discharge silo (20), and the lower end of the discharge shell (32) is connected to the slag discharge pipe (33).

7. A multi-stage treatment device for wastewater from water-based varnish production according to claim 6, characterized in that: A heating plate is installed at the inner bottom of the discharge shell (32), and an exhaust window (34) is detachably connected to the upper portion of the discharge shell (32).

8. A multi-stage treatment device for wastewater from water-based varnish production according to any one of claims 2 to 7, characterized in that: The bottoms of the primary sedimentation tank (1) and the secondary sedimentation tank (2) are both funnel-shaped structures, and the lower ends of the funnel-shaped structures are connected to the aggregate trough (4).

9. A multi-stage treatment device for wastewater from water-based varnish production according to claim 3, characterized in that: A tension spring is connected between the side of the positioning slide block (22) away from the driving shaft (24) and the positioning slide groove (21).

10. A multi-stage treatment process for wastewater from water-based varnish production, characterized in that: The multi-stage treatment device for wastewater from water-based varnish production according to any one of claims 1 to 9 specifically comprises the following steps: Step 1: transporting the wastewater to a primary sedimentation tank (1), and adding a flocculant to the primary sedimentation tank (1); Step 2: After the flocculation of the primary sedimentation tank (1) is completed, the dewatering structure transports the sludge at the bottom of the primary sedimentation tank (1) upward and squeezes and dehydrates it, and the water discharged by squeezing falls back into the primary sedimentation tank (1), and the dehydrated waste residue is discharged through the residue discharge structure; Step 3: After the dehydration work of the dehydration structure is completed, the cleaning component cleans the dehydration structure, and at the same time, the water that has been precipitated in the primary sedimentation tank (1) is transported to the secondary sedimentation tank (2), and new wastewater is added to the primary sedimentation tank (1); Step 4: adding flocculant to the primary sedimentation tank (1) and adding flocculant to the secondary sedimentation tank (2) again; Step 5: After the sedimentation in the primary sedimentation tank (1) is completed, the dewatering structure transports the sludge at the bottom of the primary sedimentation tank (1) and the secondary sedimentation tank (2) upward and squeezes out the water, and the squeezed out water falls back to the corresponding primary sedimentation tank (1) and the secondary sedimentation tank (2), and the dewatered waste residue is discharged through the residue discharge structure.

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