A wastewater treatment system for powder coating process

Abstract

The present invention relates to the technical field of powder coating, and in particular to a wastewater treatment system for powder coating process. It includes an integrated flotation sedimentation pool, which includes a pool body and a column with a sealing plate; the column includes an outer shell and an inner shell, the inner shell wall is provided with air holes, the bottom plate of the pool body is provided with an air inlet, the air cavity is provided with a mounting ring and a connecting shaft, the outer ring surface of the mounting ring is connected to the inner wall of the inner shell through a plurality of single rods, the connecting shaft is connected to the inner ring surface of the mounting ring through a rotating bearing, a fan blade is provided at one end of the connecting shaft close to the air inlet, and the other end passes through the sealing plate and is provided with an air flotation scraper; a fluidizing plate is provided between the outer shell and the inner shell to divide the cavity between the outer shell and the inner shell into a medicine cavity and an electrostatic cavity, the medicine cavity is loaded with medicine powder, and the electrostatic cavity is provided with an electrostatic generator; a plurality of through holes are provided on the outer shell wall, and the through holes are all covered with a first one-way plate. The present application has the characteristics of rapid flocculation and complete reaction.

Description

Technical Field

[0001] The invention relates to the technical field of powder coating, and in particular to a wastewater treatment system for a powder coating process. Background Art

[0002] Powder spraying is the process of spraying powder coating onto the surface of a workpiece using powder spraying equipment. Under the action of static electricity, the powder will be evenly adsorbed on the surface of the workpiece to form a powdery coating; the powdery coating is leveled and solidified through high-temperature baking to become a final coating with different effects (different types of powder coating effects); the spraying effect of powder spraying is superior to the painting process in terms of mechanical strength, adhesion, corrosion resistance, and aging resistance, and the cost is also lower than that of painting with the same effect.

[0003] The wastewater generated in the coating process is mainly divided into pre-treatment wastewater, electrophoresis wastewater and paint spraying wastewater. The patent document with publication number CN205933486U discloses such a coating wastewater treatment device, including a grease trap, a regulating tank, a combined sedimentation tank, a flotation tank, a sand filter, and a carbon filter connected in sequence by pipelines. The sludge generated by the combined sedimentation tank flows into the sludge drying tank through a pipeline, and the filtrate generated by the sludge drying tank flows into the regulating tank through a pipeline. This application uses the flotation tank and the combined sedimentation tank separately, which increases the operation steps and has a high operating cost. Meanwhile, the use principle of the traditional flotation tank is: firstly, the aerator and the driving motor are electrically connected to the external power supply, then the wastewater is transported to the inside of the aeration chamber through the water inlet pipe, then the aerator is turned on to generate a large number of microbubbles, the microbubbles are fully mixed with the wastewater and enter the reaction chamber through the drainage hole, then a coagulant is added to the reaction chamber through the scraping operation port, so that the coagulant and the impurities in the wastewater are subjected to flocculation reaction, the generated floccules and the suspended solids contained in the wastewater are continuously raised and floated on the liquid surface through a large number of microbubbles, then the driving motor is turned on to drive the scraper to scrape off the floccules and suspended solids floating on the liquid surface, and discharge them through the sewage plate and the sewage outlet, and finally the remaining water can be discharged through the drainage outlet; in the use of the existing flotation tank, it is found that the transmission chain of the scraper is often loose during use, which affects the scraping operation of the scraper, resulting in low reliability of use; at the same time, the added coagulant cannot be fully mixed with the wastewater, resulting in incomplete flocculation of the wastewater, and the use limitation is high. Summary of the invention

[0004] The present invention aims to solve the above-mentioned problem and provides a wastewater treatment system for a powder coating process.

[0005] The technical solution to solve the problem of the present invention is to provide a wastewater treatment system for a powder coating process, including an integrated flotation and sedimentation pool, the integrated flotation and sedimentation pool including a pool body and a column arranged in the center of the inner cavity of the pool body, one end of which is connected to the bottom surface of the pool body, and the other end of which is provided with a sealing plate; the column includes an outer shell and an inner shell, the inner cavity of the inner shell forms a wind cavity, the inner shell wall is provided with wind holes, the part of the pool body bottom plate located in the wind cavity is provided with an air inlet, the wind cavity is provided with a mounting ring and a connecting shaft, the outer ring surface of the mounting ring is connected to the inner wall of the inner shell by a plurality of single rods, and the connecting shaft is connected to the inner ring surface of the mounting ring by a rotating bearing , one end of the connecting shaft close to the air inlet is provided with a fan blade for receiving airflow for rotation, the other end passes through the sealing plate and is provided with an air flotation scraper, and the connecting shaft is connected to the sealing plate through a rotating bearing; a fluidizing plate is provided between the outer shell tube and the inner shell tube to divide the cavity between the outer shell tube and the inner shell tube into a medicine chamber and an electrostatic chamber, the medicine chamber is loaded with medicine powder, and the electrostatic chamber is provided with an electrostatic generator; a plurality of through holes are opened on the wall of the outer shell tube, and the through holes are all covered with a first one-way plate, one end of the first one-way plate is connected to the outer side surface of the outer shell tube, and the other end is attached to the outer side surface of the outer shell tube, and its body covers the through hole.

[0006] As a preferred embodiment of the present invention, the inner diameter of the through hole is smaller than the inner diameter of the air hole.

[0007] As a preferred embodiment of the present invention, a receiving plate for collecting the floating matter collected by the floating scraper is provided in the pool body.

[0008] As a preferred embodiment of the present invention, adsorption cotton is provided on one side of the receiving plate close to the inner bottom surface of the pool body.

[0009] As a preferred embodiment of the present invention, the receiving plate is connected to the lifting member.

[0010] As a preferred embodiment of the present invention, a truncated cone-shaped sedimentation guide plate is further provided in the tank body, the upper end of the truncated cone of the sedimentation guide plate is sleeved on the column, and the lower end of the truncated cone is connected to the side of the tank body; a sedimentation outlet is provided on the side of the tank body; and activated sludge is laid on the surface of the sedimentation guide plate.

[0011] As a preferred embodiment of the present invention, the through hole includes an impact inclined hole located in the electrostatic cavity, and the impact inclined hole is parallel to the sedimentation guide plate busbar in the same vertical plane as the impact inclined hole.

[0012] As a preferred embodiment of the present invention, the through hole also includes a mixing inclined hole located in the medicine chamber, the mixing inclined hole includes an inner end close to the inner shell tube and an outer end away from the inner shell tube, and the horizontal plane where the outer end is located is higher than the horizontal plane where the inner end is located.

[0013] As a preferred embodiment of the present invention, the air holes are all covered with a waterproof and breathable membrane.

[0014] As a preferred embodiment of the present invention, the air holes are covered with a second one-way plate, one end of the second one-way plate is connected to the outer side of the inner shell tube, the other end is attached to the outer side of the inner shell tube, and its body covers the air holes.

[0015] Beneficial effects of the present invention:

[0016] 1. The present application adopts the arrangement of the fan blade and the reagent chamber. In the process of using the fan blade to intake air, the airflow passes through the reagent chamber and carries a part of the reagent into the pool body to mix with the wastewater. In the process of the airflow and the wastewater forming microbubbles, the mixed flocculation of the wastewater and the reagent is completed. Then, the microbubbles directly drive the part of the flocculated impurities to rise to the liquid surface, and the flocculation effect is good.

[0017] 2. At the same time, the present application also combines the process of mixing gas, liquid and medicine with the process of scraping impurities by connecting the fan blades and the air flotation scraper. The greater the air intake, the more microbubbles are generated, and the more flocculated impurities are driven to float up; and the greater the air intake, the greater the rotation speed of the air flotation scraper, so it can effectively scrape off more flocculated impurities.

[0018] 3. At the same time, the present application also uses an electrostatic generator to charge the reagent powder and suspend it in the reagent chamber. On the one hand, the airflow coming out of each air hole can drive a part of the reagent into the pool body; on the other hand, the charged reagent can not only flocculate the impurities, but also effectively adsorb the impurities that cannot undergo flocculation reaction; in addition, after the charged airflow enters the wastewater, it can also increase the activity of the activated sludge on the sedimentation guide plate. The bacteria, fungi, algae and other microorganisms in the activated sludge can bind the heavy metals in the wastewater to the cell wall surface through electrostatic adsorption, further improving the wastewater treatment effect.

[0019] 4. The air-floating scraper of the present application works by the rotation of the fan blades, and is not provided with a connecting structure such as a transmission chain. As long as air flow is introduced into the air inlet, the air-floating scraper can operate, and its operation reliability is high.

[0020] 5. The present application provides an impact inclined hole so that a part of the airflow can impact the sediment on the sedimentation guide plate toward the sedimentation outlet, thereby helping the sediment to be discharged from the sedimentation outlet. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of an integrated air flotation and sedimentation tank in a wastewater treatment system for a powder coating process;

[0022] In the figure: pool body 1, air inlet 11, receiving plate 12, sedimentation guide plate 13, sedimentation outlet 14, column 2, outer shell 21, fluidizing plate 211, electrostatic generator 212, through hole 213, impact inclined hole 2131, mixing inclined hole 2132, first one-way plate 214, inner shell 22, air hole 221, mounting ring 222, connecting shaft 223, single rod 224, fan blade 225, flotation scraper 226, sealing plate 23. DETAILED DESCRIPTION

[0023] The following are specific implementations of the present invention, and in conjunction with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0024] A wastewater treatment system for powder coating process, which includes a regulating tank, an integrated flotation sedimentation tank, a neutralization reaction tank, a hydroxyl solution generation system, a filter adsorber and a clean water reuse tank. When in use, the coating wastewater first passes through the regulating tank and enters the integrated flotation sedimentation tank, and the water is discharged after flotation sedimentation; then the wastewater is sent to the neutralization reaction tank, and the pH value of the wastewater is adjusted by reacting with the reagent to make the pH range of the wastewater between 6.0 and 9.0; then the neutralized wastewater is sent to the hydroxyl solution generation system through a sewage circulation pump, and the strong ionization discharge device in the hydroxyl solution generation system generates OH, O3, O2+, O2-, H2O + , H2O2 and ·HO2 active particles, under the action of the ejector and sewage circulation pump, convert ·OH, O3, O2+, O2-, H2O + , H2O2 and ·HO2 active particles are injected into the gas-liquid mixing device, mixed with the wastewater to produce ·OH solution, which oxidizes and degrades the coating wastewater; the wastewater after oxidation and degradation flows into the gas-liquid separation device for gas-liquid separation, and the undissolved O2 and O3 are discharged at the same time; finally, the treated wastewater is input into the filter adsorber, and after filtration, it enters the clean water reuse pool; at the same time, the scum and precipitate collected in the air flotation and sedimentation integrated pool are dehydrated by the chamber filter press to make the sludge moisture content below 80%, and the supernatant is returned to the regulating tank.

[0025] Among them, Figure 1As shown, the integrated air flotation sedimentation pool includes a pool body 1 and a column 2 arranged at the center of the inner cavity of the pool body 1, one end of which is connected to the inner bottom surface of the pool body 1, and the other end of which is provided with a sealing plate 23; the column 2 includes an outer shell 21 and an inner shell 22, the inner cavity of the inner shell 22 forms a wind cavity, the wall of the inner shell 22 is provided with a wind hole 221, and the portion of the bottom plate of the pool body 1 located in the wind cavity is provided with an air inlet 11. A fluidizing plate 211 is provided between the outer shell 21 and the inner shell 22 to divide the cavity between the outer shell 21 and the inner shell 22 into a medicine cavity and an electrostatic cavity, the medicine cavity is loaded with medicine powder, and the electrostatic cavity is provided with an electrostatic generator 212; a plurality of through holes 213 are provided on the wall of the outer shell 21, and the through holes 213 are all covered with a first one-way plate 214, one end of the first one-way plate 214 is connected to the outer side surface of the outer shell 21, and the other end is attached to the outer side surface of the outer shell 21, and its body covers the through holes 213. In addition, in order to prevent the powder from flowing from the medicine chamber to the wind chamber, the air holes 221 can be covered with a waterproof and breathable membrane, or the air holes 221 can be covered with a second one-way plate, one end of the second one-way plate is connected to the outer side surface of the inner shell tube 22, and the other end is attached to the outer side surface of the inner shell tube 22, and its body covers the air holes 221.

[0026] When in use, the airflow enters the air cavity from the air inlet 11, and then enters the medicine cavity and the electrostatic cavity from the air hole 221 through the waterproof breathable membrane or the second one-way plate. The electrostatic generator in the electrostatic cavity charges the airflow, and then enters the medicine cavity through the fluidizing plate 211, so that the powder loaded on the fluidizing plate 211 is charged and evenly fluidized under the charged current, and the powder is evenly suspended in the medicine cavity under the action of static electricity. Then the airflow entering the medicine cavity drives the suspended powder into the through hole 213, and under the action of wind force, the first one-way plate 214 is opened, so that the airflow carrying the powder enters the pool body 1 and mixes with the wastewater for flocculation and adsorption. At the same time, the airflow entering the pool body 1 mixes with the wastewater to form microbubbles.

[0027] The powder includes polyaluminium chloride, polyacrylamide and active bacteria, so as to achieve coagulation and flocculation of impurities in the wastewater through polyaluminium chloride and polyacrylamide, and electrostatic adsorption of impurities in the wastewater through active bacteria. Impurities that have completed coagulation naturally settle to the bottom of the tank body 1, impurities that have completed flocculation rise to the liquid surface with microbubbles, and impurities that have completed adsorption settle or float according to their gravity.

[0028] In order to increase the impact force of the airflow entering the wastewater and increase the generation of microbubbles, the inner diameter of the through hole 213 can be set to be smaller than the inner diameter of the air hole 221. However, in order to avoid the impact of the airflow on the sediment at the bottom of the pool body 1, so that the sediment is stirred up and remixed with the wastewater, the through hole 213 includes a mixing inclined hole 2132 located in the medicine chamber, and the mixing inclined hole 2132 includes an inner end close to the inner shell tube 22 and an outer end away from the inner shell tube 22, and the horizontal plane where the outer end is located is higher than the horizontal plane where the inner end is located, so that the airflow is ejected in the direction of the liquid surface. Based on this, in order to increase the degree of combination of the airflow and the powder in the medicine chamber, the end of the air hole 221 close to the medicine chamber can be made lower than the end away from the medicine chamber, and the air outlet of the air hole 221 close to the medicine chamber is located between the air inlets of the two mixing inclined holes 2132, and a stop plate is provided at the top of the lower mixing inclined hole 2132.

[0029] In order to remove floating impurities, in the present application, the air cavity is provided with a mounting ring 222 and a connecting shaft 223. The outer ring surface of the mounting ring 222 is connected to the inner wall of the inner shell 22 through a plurality of single rods 224. The connecting shaft 223 is connected to the inner ring surface of the mounting ring 222 through a rotating bearing. The end of the connecting shaft 223 close to the air inlet 11 is provided with a fan blade 225 for receiving air flow for rotation. The other end passes through the sealing plate 23 and is provided with an air flotation scraper 226. The connecting shaft 223 is connected to the sealing plate 23 through a rotating bearing. When the air flow enters the air cavity from the air inlet 11, the fan blade 225 will rotate, thereby driving the connecting shaft 223 and the air flotation scraper 226 to rotate, so that the air flotation scraper 226 can scrape the scum on the liquid surface.

[0030] Generally, after scraping off the scum, it is necessary to collect the scum. Therefore, a receiving plate 12 is provided in the tank body 1 for collecting the air-floating scum collected by the air-floating scraper 226. The receiving surface of the receiving plate 12 is lower than the bottom surface of the air-floating scraper 226, so that the air-floating scraper 226 can scrape the scum onto the receiving plate 12. At the same time, since the receiving plate 12 blocks a part of the liquid surface, the scum on this part of the liquid surface cannot be collected by the air-floating scraper 26. Therefore, an adsorbent cotton is provided on one side of the receiving plate 12 close to the bottom surface of the tank body 1. Of course, any connecting parts can also be used to move the placement position of the receiving plate 12 on the liquid surface to avoid the receiving plate 12 blocking the scum. For example, a reducer (such as a planetary gear reducer) can be installed on the part of the connecting shaft 223 located outside the column 2, and the end of the receiving plate 13 can be connected to the reducer, so that the receiving plate 13 rotates in the same direction with the flotation scraper 226, but the rotation speed of the receiving plate 13 is lower than the rotation speed of the flotation scraper 226.

[0031] After the receiving plate 12 collects a certain amount of scum, it is necessary to dispose of the scum on the receiving plate 12 and place it on the liquid surface for use. As in the present embodiment, the receiving plate 12 can be connected to the lifting member. After the receiving plate 12 collects impurities, the lifting member is used to make the receiving plate 12 drive the impurities out of the water body, and then place the receiving plate 12 on the liquid surface after treatment. At the same time, the lifting member can be used to adjust the height of the receiving plate 12 in the wastewater according to the amount of scum. The more scum there is, the greater the distance of the receiving plate 12 relative to the liquid surface.

[0032] In order to remove the deposited sediment, in this embodiment, a truncated cone-shaped sedimentation guide plate 13 is further provided in the pool body 1, the upper end of the truncated cone of the sedimentation guide plate 13 is sleeved on the column 2, and the lower end of the truncated cone is connected to the side of the pool body 1; a sedimentation outlet 14 is provided on the side of the pool body 1. After the sediment is deposited on the sedimentation guide plate 13, it can slide along the inclined side of the sedimentation guide plate to the sedimentation outlet 14 for discharge. At the same time, for some sediments with high viscosity that are difficult to slide to the sedimentation outlet 14, the through hole 213 can include an impact inclined hole 2131 located in the electrostatic chamber, and the impact inclined hole 2131 is parallel to the generatrix of the sedimentation guide plate 13 on the same vertical plane as the same, so that a part of the airflow can be used to specifically flush the sediment.

[0033] In addition, activated sludge may be laid on the surface of the sedimentation guide plate 13 to further improve the wastewater treatment effect.

[0034] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A wastewater treatment system for a powder coating process, characterized in that: The invention comprises an integrated air flotation and sedimentation pool, the integrated air flotation and sedimentation pool comprising a pool body (1) and a column (2) arranged at the center of the inner cavity of the pool body (1), one end of which is connected to the inner bottom surface of the pool body (1), and the other end of which is provided with a sealing plate (23); the column (2) comprises an outer shell (21) and an inner shell (22); the inner cavity of the inner shell (22) forms a wind cavity; the wall of the inner shell (22) is provided with a wind hole (221); a portion of the bottom plate of the pool body (1) located in the wind cavity is provided with an air inlet (11); the wind cavity is provided with a mounting ring (222) and a connecting shaft (223); the outer ring surface of the mounting ring (222) is connected to the inner wall of the inner shell (22) via a plurality of single rods (224); the connecting shaft (223) is connected to the inner ring surface of the mounting ring (222) via a rotating bearing; the connecting shaft (223) is close to the air inlet (11); A fan blade (225) for receiving airflow for rotation is provided at one end, and an air flotation scraper (226) is provided at the other end passing through the sealing plate (23), and the connecting shaft (223) is connected to the sealing plate (23) via a rotating bearing; a fluidizing plate (211) is provided between the outer shell cylinder (21) and the inner shell cylinder (22) to divide the cavity between the outer shell cylinder (21) and the inner shell cylinder (22) into a medicine cavity and an electrostatic cavity, wherein the medicine cavity is loaded with medicine powder, and the electrostatic cavity is provided with an electrostatic generator (212); a plurality of through holes (213) are provided on the wall of the outer shell cylinder (21), and the through holes (213) are all covered with a first one-way plate (214), one end of the first one-way plate (214) is connected to the outer side surface of the outer shell cylinder (21), and the other end is attached to the outer side surface of the outer shell cylinder (21), and its body covers the through holes (213); The inner diameter of the through hole (213) is smaller than the inner diameter of the air hole (221); The pool body (1) is provided with a receiving plate (12) for collecting the floating matter collected by the floating scraper (226).

2. A wastewater treatment system for a powder coating process according to claim 1, characterized in that: A surface of the receiving plate (12) close to the inner bottom surface of the pool body (1) is provided with adsorption cotton.

3. A wastewater treatment system for a powder coating process according to claim 1, characterized in that: The receiving plate (12) is connected to the lifting member.

4. A wastewater treatment system for a powder coating process according to claim 1, characterized in that: A truncated cone-shaped sedimentation guide plate (13) is also provided in the tank body (1), the upper end of the truncated cone of the sedimentation guide plate (13) being sleeved on the column (2) and the lower end of the truncated cone being connected to the side of the tank body (1); a sedimentation outlet (14) is provided on the side of the tank body (1); and activated sludge is laid on the surface of the sedimentation guide plate (13).

5. A wastewater treatment system for powder coating process according to claim 4, characterized in that: The through hole (213) comprises an impact inclined hole (2131) located in the electrostatic chamber, and the impact inclined hole (2131) is parallel to a generatrix of a precipitation guide plate (13) on the same vertical plane as the through hole (213).

6. A wastewater treatment system for powder coating process according to claim 5, characterized in that: The through hole (213) further comprises an inclined mixing hole (2132) located in the medicine chamber, the inclined mixing hole (2132) comprising an inner end close to the inner shell tube (22) and an outer end away from the inner shell tube (22), the horizontal plane where the outer end is located is higher than the horizontal plane where the inner end is located.

7. A wastewater treatment system for a powder coating process according to claim 1, characterized in that: The air holes (221) are all covered with a waterproof and breathable membrane.

8. A wastewater treatment system for a powder coating process according to claim 1, characterized in that: The air holes (221) are all covered with a second one-way plate, one end of the second one-way plate is connected to the outer side surface of the inner shell tube (22), the other end is attached to the outer side surface of the inner shell tube (22), and the body of the second one-way plate covers the air holes (221).

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