Electroplating wastewater treatment device and process

Abstract

The present application relates to wastewater treatment technical field, especially to a kind of electroplating wastewater treatment device and process, in turn include adsorption tower, sedimentation tank, ion exchange pool, heat exchange tank, heat exchanger, falling film evaporator, active carbon is used in adsorption tower for adding electroplating wastewater, adsorption tower is connected with sedimentation tank, sedimentation tank is used for adding cyanide and chromium compound removal reagent, sedimentation tank is connected with ion exchange pool, ion exchange pool is used to exchange the metal ion in electroplating wastewater;Heat exchange tank one end is connected with ion exchange pool, the other end of heat exchange tank is connected with heat exchanger, heat exchange tank is used to pass into heat exchanger and carry out heat exchange for electroplating wastewater, heat exchanger is connected with falling film evaporator, falling film evaporator is used to evaporate and concentrate electroplating wastewater;Heat exchanger and heat exchange tank are also provided with reflux pipe, reflux pipe is used to pass into heat exchange tank for the electroplating wastewater that temperature is not enough to evaporate.Electroplating wastewater is evaporated and concentrated after sedimentation and ion exchange, and processing effect is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a kind of electroplating wastewater treatment device and process. BACKGROUND

[0002] A large number of electroplating processes are needed in the manufacture of printed circuit boards, thus generating more electroplating wastewater. The water quality of electroplating wastewater is complex, and the composition is not easy to control. It contains heavy metal ions such as chromium, cadmium and nickel, and also contains cyanide and other toxic substances. Therefore, the treatment process of electroplating wastewater is relatively complex. In the prior art, the electroplating wastewater is usually treated by precipitation method and ion exchange method. The precipitation method is less stable but has lower cost, and the ion exchange method has stable effect but higher cost. Moreover, the salt content in the treated wastewater is high, and the treatment effect of the electroplating wastewater treated by the two methods is not good. SUMMARY

[0003] To solve the problem that the electroplating wastewater treated by the precipitation method and the ion exchange method in the prior art is prone to poor treatment effect, the present application provides an electroplating wastewater treatment device, and the specific scheme is as follows.

[0004] An electroplating wastewater treatment device sequentially includes an adsorption tower, a sedimentation tank, an ion exchange tank, a heat exchange tank, a heat exchanger and a falling film evaporator. Activated carbon is added into the adsorption tower together with electroplating wastewater. The adsorption tower is connected with the sedimentation tank. The sedimentation tank is used for adding reagents for removing cyanide and chromium compounds. The sedimentation tank is connected with the ion exchange tank. The ion exchange tank is used for exchanging metal ions in the electroplating wastewater.

[0005] One end of the heat exchange tank is connected with the ion exchange tank, and the other end of the heat exchange tank is connected with the heat exchanger. The heat exchange tank is used for passing the electroplating wastewater into the heat exchanger for heat exchange. The heat exchanger is connected with the falling film evaporator. The falling film evaporator is used for evaporating and concentrating the electroplating wastewater.

[0006] A reflux pipe is further arranged between the heat exchanger and the heat exchange tank. The reflux pipe is used for passing the electroplating wastewater with insufficient temperature into the heat exchange tank.

[0007] By adopting the above technical scheme, the electroplating wastewater is subjected to both precipitation by activated carbon and ion exchange by the ion exchange tank. The two methods can complement the shortcomings of the other method, reduce the shortcomings of the two methods, and further separate the waste material by evaporating and concentrating the electroplating wastewater in the subsequent treatment process, thereby further improving the treatment effect of the wastewater.

[0008] Optionally, the heat exchanger is further provided with a heat exchange pipe and a discharge pipe, one end of the heat exchange pipe is connected with the heat exchange tank, the other end of the heat exchange pipe is provided with a partition plate, the partition plate divides the heat exchange pipe into two independent spaces which are not communicated with each other, the heat exchange pipe on one side of the partition plate is communicated with the discharge pipe, the end of the discharge pipe away from the heat exchange pipe is communicated with the falling film evaporator, the heat exchange pipe on the other side of the partition plate is communicated with the return pipe, the end of the return pipe away from the heat exchange pipe is communicated with the heat exchange tank, the side of the heat exchange pipe communicated with the return pipe is provided with a heat sensitive block, the heat sensitive block blocks the passage when it is heated and expanded.

[0009] By adopting the above technical scheme, the liquid in the heat exchange pipe can absorb the heat energy of the heat exchanger to be heated and evaporated, the electroplating wastewater reaching the evaporation temperature is discharged into the falling film evaporator through the discharge pipe, and the electroplating wastewater is divided into the return pipe and the discharge pipe through the partition plate, so as to reduce the overall flow rate of the electroplating wastewater. When the overall temperature of the electroplating wastewater is relatively high and reaches the evaporation temperature, the flow channel volume is reduced by closing the return pipe, so as to increase the flow rate of the electroplating wastewater reaching the evaporation temperature entering the discharge pipe, so that the electroplating wastewater can enter the falling film evaporator to be evaporated and concentrated, and the situation that the electroplating wastewater cannot be evaporated due to the low temperature is reduced. When the temperature of the electroplating wastewater cannot be closed, the return pipe is opened, the part of the electroplating wastewater is returned to the heat exchange tank to increase the temperature of the heat exchange tank, so that the electroplating wastewater in the heat exchange tank can reach a higher temperature when being heated, and the part of the electroplating wastewater entering the falling film evaporator through the discharge pipe can reach the evaporation temperature after being mixed with the electroplating wastewater returned from the return pipe.

[0010] Optionally, the heat sensitive block is fixedly connected with the partition plate, and a rubber pad is fixedly arranged on the heat sensitive block and used for abutting against the inner wall of the heat exchange pipe.

[0011] By adopting the above technical scheme, the rubber pad is arranged on the heat exchange pipe and can be closely abutted against the inner wall of the heat exchange pipe, so as to reduce the leakage of the water flow from the gap.

[0012] Optionally, the heat exchange pipe on the upper side of the partition plate is communicated with the discharge pipe, and the heat exchange pipe on the lower side of the partition plate is communicated with the return pipe.

[0013] By adopting the above technical scheme, since the density of the hot water is smaller than that of the cold water, the hot water with high temperature is more likely to be in the upper layer of the cold water when the electroplating wastewater with temperature difference flows at the same time. At this time, the electroplating wastewater with high temperature on the upper side can enter the falling film evaporator through the discharge pipe, and the electroplating wastewater with low temperature on the lower side can re-enter the heat exchange tank through the return pipe to be heated again.

[0014] Optionally, a heat sensitive strip is further fixedly arranged in the heat exchange pipe, the heat sensitive strip is arranged along the length direction of the heat exchange pipe, and the heat sensitive strip does not abut against the inner wall of the heat exchange pipe when it is expanded.

[0015] By adopting the above technical solution, the heat-sensitive strip is arranged in the heat exchange tank, and the heat-sensitive strip can further reduce the volume in the heat exchange pipe after expansion. At this time, the heat-sensitive block closes the passage of the return pipe. Since the volume at the discharge pipe remains unchanged, the flow rate at the discharge pipe can be further increased under the condition that the water flow per second remains unchanged. Therefore, when the temperature meets the evaporation condition, the electroplating wastewater can enter the falling film evaporator through the discharge pipe at a faster efficiency.

[0016] Optionally, the heat-sensitive strip is arranged on the lower side of the partition plate, and the heat-sensitive strip is arranged along the inner wall of the heat exchange pipe and fixedly connected with the inner wall of the heat exchange pipe.

[0017] By adopting the above technical solution, the heat-sensitive strip is arranged on the lower side of the partition plate, and the heat-sensitive strip can guide the electroplating wastewater to the position close to the discharge pipe when expanding, thereby further improving the speed of the electroplating wastewater meeting the evaporation temperature entering the discharge pipe.

[0018] Optionally, the heat-sensitive strip is arranged at a position close to the partition plate of the heat exchange pipe, and the heat-sensitive strip can abut against the partition plate when expanding under the heat.

[0019] By adopting the above technical solution, the heat-sensitive strip is arranged at a position close to the partition plate, and the heat-sensitive strip can assist the heat-sensitive block in shielding the return pipe, thereby further reducing the case that the electroplating wastewater enters the return pipe when the heat of the electroplating wastewater meets the evaporation condition.

[0020] Optionally, the partition plate is arranged along the length direction of the heat exchange pipe and along the axis of the heat exchange pipe, the space cross-sectional areas on the upper side and the lower side of the partition plate are the same, and the partition plate is fixedly connected with the inner wall of the heat exchange pipe.

[0021] By adopting the above technical solution, the partition plate is arranged along the length direction of the heat exchange pipe and along the axis of the heat exchange tank, and the cross-sectional areas on the upper side and the lower side of the partition plate are the same, thereby reducing the case that the flow rates are different when the electroplating wastewater enters the discharge pipe and the return pipe.

[0022] The application also provides an electroplating wastewater treatment process, which comprises the electroplating wastewater treatment device and adopts the following method.

[0023] a. The electroplating wastewater is sent into the adsorption tower to be adsorbed by the activated carbon.

[0024] b. The electroplating wastewater after the adsorption is sent into the sedimentation tank to be further precipitated and to treat cyanide and chromium compounds.

[0025] c. The electroplating wastewater is sent into the ion exchange tank to be ion exchanged.

[0026] d. The electroplating wastewater is sent into the heat exchange tank and is punched into the heat exchanger to be heat exchanged.

[0027] e、temperature is sufficient to evaporate the electroplating wastewater into the falling film evaporator, and the electroplating wastewater with insufficient temperature is returned to the heat exchange tank.

[0028] By adopting the technical scheme, the electroplating wastewater is treated by the precipitation method and the ion exchange method in sequence, the precipitation method and the ion exchange method are complementary to each other, the treatment effect is improved, and then the treated wastewater is introduced into the falling film evaporator to evaporate and concentrate, so that the waste is further separated from the wastewater, thereby reducing the poor treatment effect of the wastewater treatment.

[0029] In summary, the present application has at least the following beneficial effects:

[0030] 1. The present application solves the problems of cost difficult to control and poor treatment effect of the electroplating wastewater treated by the precipitation method and the ion exchange method in the prior art. The present application treats the electroplating wastewater by two methods in sequence, the two treatment methods are complementary to each other, which can reduce the poor treatment effect when only one method is used, and the evaporation and concentration treatment method is added after the two methods, which further improves the treatment effect of the wastewater.

[0031] 2. The present application further comprises a heat exchanger capable of judging whether the electroplating wastewater meets the evaporation temperature, and the electroplating wastewater not meeting the evaporation temperature is returned, thereby reducing the situation that the temperature of the electroplating wastewater cannot meet the evaporation temperature in the evaporation and concentration process, and further improving the treatment effect. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a perspective view of the present embodiment.

[0033] Figure 2 is a sectional view of the present embodiment.

[0034] REFERENCE SIGNS:

[0035] 1. adsorption tower;

[0036] 2. sedimentation tank;

[0037] 3. ion exchange tank;

[0038] 4. heat exchange tank;

[0039] 5. heat exchanger; 51, return pipe; 52, heat exchange pipe; 521, partition; 522, heat-sensitive block; 523, rubber pad; 524, heat-sensitive strip; 53, discharge pipe;

[0040] 6. falling film evaporator;

[0041] 7. water pump. DETAILED DESCRIPTION

[0042] The application will be further described in detail below with reference to the accompanying drawings.

[0043] A kind of electroplating wastewater treatment device, as shown in Figure 1 The end of heat exchange tank 4 is connected with ion exchange tank 3, and the other end of heat exchange tank 4 is connected with heat exchanger 5, heat exchange tank 4 is used to pass electroplating wastewater into heat exchanger 5 for heat exchange, heat exchanger 5 is connected with falling film evaporator 6, falling film evaporator 6 is used to evaporate and concentrate electroplating wastewater, and backflow pipe 51 is further arranged between heat exchanger 5 and heat exchange tank 4, which is used to pass electroplating wastewater with insufficient temperature into heat exchange tank 4 for evaporation. In specific implementation, electroplating wastewater after completing the previous steps is sent into falling film evaporator 6 for further treatment, but the temperature of electroplating wastewater needs to reach the evaporation temperature before being sent into falling film evaporator 6 for normal evaporation and concentration. In other embodiments, multiple heat exchangers 5 can be arranged in heat exchange tank 4 and falling film evaporator 6 to further improve the effect of increasing the temperature of electroplating wastewater, so that the temperature of electroplating wastewater entering falling film evaporator 6 can meet the evaporation temperature, and crystallization separation equipment can also be arranged after falling film evaporator 6 to further treat wastewater and further increase the treatment effect of wastewater.

[0044] As shown in Figure 1 The end of heat exchange tank 4 is connected with ion exchange tank 3, and the other end of heat exchange tank 4 is connected with heat exchanger 5, heat exchange tank 4 is used to pass electroplating wastewater into heat exchanger 5 for heat exchange, heat exchanger 5 is connected with falling film evaporator 6, falling film evaporator 6 is used to evaporate and concentrate electroplating wastewater, and backflow pipe 51 is further arranged between heat exchanger 5 and heat exchange tank 4, which is used to pass electroplating wastewater with insufficient temperature into heat exchange tank 4 for evaporation. In specific implementation, electroplating wastewater after completing the previous steps is sent into falling film evaporator 6 for further treatment, but the temperature of electroplating wastewater needs to reach the evaporation temperature before being sent into falling film evaporator 6 for normal evaporation and concentration. In other embodiments, multiple heat exchangers 5 can be arranged in heat exchange tank 4 and falling film evaporator 6 to further improve the effect of increasing the temperature of electroplating wastewater, so that the temperature of electroplating wastewater entering falling film evaporator 6 can meet the evaporation temperature, and crystallization separation equipment can also be arranged after falling film evaporator 6 to further treat wastewater and further increase the treatment effect of wastewater.

[0045] As shown in Figure 1 and Figure 2As shown, the heat exchanger 5 is further provided with a heat exchange pipe 52 and a discharge pipe 53. One end of the heat exchange pipe 52 is connected with the heat exchange tank 4, and the other end of the heat exchange pipe 52 is provided with a partition plate 521, which divides the heat exchange pipe 52 into two independent spaces. The heat exchange pipe 52 on one side of the partition plate 521 is in communication with the discharge pipe 53, and the other end of the discharge pipe 53 is in communication with the falling film evaporator 6. The heat exchange pipe 52 on the other side of the partition plate 521 is in communication with the return pipe 51, and the other end of the return pipe 51 is in communication with the heat exchange tank 4. A heat-sensitive block 522 is arranged on the side of the heat exchange pipe 52 in communication with the return pipe 51, and the heat-sensitive block 522 blocks the passage when it expands due to heat. In specific implementation, the heat exchanger 5 can heat the electroplating wastewater in the heat exchange pipe 52. Since the partition plate 521 divides the heat exchange pipe 52 into two parts, when the electroplating wastewater in the heat exchange pipe 52 rises to a temperature that meets the evaporation condition, the heat-sensitive block 522 blocks the passage of the return pipe 51, and the flow rate of the wastewater flowing into the discharge pipe 53 increases. Since the volume of the wastewater flowing into the discharge pipe 53 is constant, the flow rate of the wastewater increases, so that the electroplating wastewater that meets the evaporation condition can flow into the falling film evaporator 6 at a faster speed. When the temperature of the electroplating wastewater is low, the heat-sensitive block 522 shrinks to open the passage, and the electroplating wastewater that does not meet the evaporation condition is re-fed into the heat exchange tank 4 to heat the wastewater in the heat exchange tank 4. At this time, the flow rate of the wastewater flowing into the discharge pipe 53 decreases, and the flow rate of the wastewater flowing into the falling film evaporator 6 also decreases. When the wastewater that meets the evaporation condition is fed into the falling film evaporator 6, it can mix with the previously fed wastewater to reach the evaporation condition.

[0046] As shown in Figure 1 and Figure 2 The heat-sensitive block 522 is fixedly connected with the partition plate 521, and a rubber pad 523 is fixedly arranged on the heat-sensitive block 522, which abuts against the inner wall of the heat exchange pipe 52. In specific implementation, the rubber pad 523 can be closely attached to the inner wall of the heat exchange pipe 52 to reduce the flow of the electroplating wastewater from the gap and reduce the flow rate of the wastewater that meets the evaporation condition.

[0047] As shown in Figure 2 The heat exchange pipe 52 on the upper side of the partition plate 521 is in communication with the discharge pipe 53, and the heat exchange pipe 52 on the lower side of the partition plate 521 is in communication with the return pipe 51. In specific implementation, since hot water has a lower density than cold water, hot water is usually on the upper side of cold water, so that when the temperature is insufficient, the wastewater with a higher temperature can enter the discharge pipe 53.

[0048] As shown in Figure 2As shown, the heat exchange pipe 52 is also fixedly provided with a heat-sensitive strip 524, which is arranged along the length direction of the heat exchange pipe 52 and does not abut against the inner wall of the heat exchange pipe when swelling. The heat-sensitive strip 524 is arranged at the lower side of the partition plate 521 and is arranged along the inner wall of the heat exchange pipe 52 and fixedly connected with the inner wall of the heat exchange pipe 52. The heat-sensitive strip 524 is arranged at a position close to the partition plate 521 of the heat exchange pipe 52, and when swelling due to heat, the heat-sensitive strip 524 can abut against the partition plate 521 to assist the heat-sensitive block 522 in shielding the return pipe 51. In specific implementation, when the heat-sensitive strip 524 swells due to heat, the heat-sensitive strip 524 will press upward to reduce the volume in the heat exchange pipe 52. Since the water inflow is unchanged, the flow rate of the wastewater in the heat exchange pipe 52 will increase, thereby further increasing the speed of the wastewater meeting the evaporation temperature into the discharge pipe 53.

[0049] As shown in the drawings, Figure 2 The partition plate 521 is arranged along the length direction of the heat exchange pipe 52 and along the axis of the heat exchange pipe 52, the space areas on the upper and lower sides of the partition plate 521 are the same, and the partition plate 521 is fixedly connected with the inner wall of the heat exchange pipe 52 by seamless welding.

[0050] The application also provides a plating wastewater treatment process, which comprises the plating wastewater treatment device and adopts the following method.

[0051] a. The plating wastewater is sent into the adsorption tower 1 to be adsorbed by the activated carbon;

[0052] b. The plating wastewater after adsorption is sent into the sedimentation tank 2 to be further precipitated and to treat cyanide and chromium compounds;

[0053] c. The plating wastewater is sent into the ion exchange tank 3 to be ion exchanged;

[0054] d. The plating wastewater is sent into the heat exchange tank 4 and into the heat exchanger 5 to be heat exchanged;

[0055] e. The plating wastewater with sufficient temperature for evaporation is sent into the falling film evaporator 6, and the plating wastewater with insufficient temperature is returned to the heat exchange tank 4.

[0056] Working principle: The plating wastewater is sequentially sent through each component, is treated by the precipitation method and the ion exchange method in sequence, and then is sent into the falling film evaporator 6 to be evaporated and concentrated, so as to complete the wastewater treatment.

[0057] The above is the preferred embodiment of the application, which does not limit the protection scope of the application, so that: any equivalent changes made according to the structure, shape and principle of the application should be covered in the protection scope of the application.

Claims

1. An electroplating wastewater treatment device, characterized in that: The invention comprises an adsorption tower (1), a sedimentation tank (2), an ion exchange tank (3), a heat exchange tank (4), a heat exchanger (5), and a falling film evaporator (6). The adsorption tower (1) is used to add activated carbon and electroplating wastewater. The adsorption tower (1) is connected to the sedimentation tank (2). The sedimentation tank (2) is used to add a reagent for removing cyanide and chromide. The sedimentation tank (2) is connected to the ion exchange tank (3). The ion exchange tank (3) is used to exchange metal ions in the electroplating wastewater. One end of the heat exchange tank (4) is connected to the ion exchange tank (3), and the other end of the heat exchange tank (4) is connected to the heat exchanger (5). The heat exchange tank (4) is used to pass the electroplating wastewater into the heat exchanger (5) for heat exchange. The heat exchanger (5) is connected to the falling film evaporator (6). The falling film evaporator (6) is used to evaporate and concentrate the electroplating wastewater. A reflux pipe (51) is further provided between the heat exchanger (5) and the heat exchange tank (4), and the reflux pipe (51) is used to pass electroplating wastewater whose temperature is not high enough for evaporation into the heat exchange tank (4); A heat exchange tube (52) and a discharge tube (53) are further provided in the heat exchanger (5). One end of the heat exchange tube (52) is connected to the heat exchange tank (4). The other end of the heat exchange tube (52) is provided with a partition (521). The partition (521) divides the heat exchange tube (52) into two independent spaces, one above the other, which are not connected to each other. The heat exchange tube (52) on one side of the partition (521) is connected to the discharge tube (53). The end of (53) away from the heat exchange tube (52) is connected to the falling film evaporator (6), the heat exchange tube (52) on one side of the partition (521) is connected to the return tube (51), and the end of the return tube (51) away from the heat exchange tube (52) is connected to the heat exchange tank (4). A thermal block (522) is provided on the side where the heat exchange tube (52) is connected to the return tube (51), and the thermal block (522) blocks the passage when it expands due to heat.

2. The electroplating wastewater treatment device according to claim 1, characterized in that: The thermosensitive block (522) is fixedly connected to the partition (521), and a rubber pad (523) is fixedly provided on the thermosensitive block (522), and the rubber pad (523) is used to abut against the inner wall of the heat exchange tube (52).

3. The electroplating wastewater treatment device according to claim 1, characterized in that: The heat exchange tube (52) on the upper side of the partition (521) is connected to the discharge tube (53), and the heat exchange tube (52) on the lower side of the partition (521) is connected to the return tube (51).

4. The electroplating wastewater treatment device according to claim 3, characterized in that: A thermosensitive strip (524) is also fixedly arranged in the heat exchange tube (52). The thermosensitive strip (524) is arranged along the length direction of the heat exchange tube (52). When the thermosensitive strip (524) expands, it will not abut against the inner wall of the heat exchange tube (52).

5. The electroplating wastewater treatment device according to claim 4, characterized in that: The thermosensitive strip (524) is arranged on the lower side of the partition (521), and the thermosensitive strip (524) is arranged along the inner wall of the heat exchange tube (52) and is fixedly connected to the inner wall of the heat exchange tube (52).

6. The electroplating wastewater treatment device according to claim 5, characterized in that: The thermosensitive strip (524) is arranged at a position close to the heat exchange tube (52) and the partition (521), and the thermosensitive strip (524) can abut against the partition (521) when it expands due to heat.

7. The electroplating wastewater treatment device according to claim 1, characterized in that: The partition (521) is arranged along the length direction of the heat exchange tube (52) and along the axis of the heat exchange tube (52); the spatial cross-sectional areas on the upper and lower sides of the partition (521) are the same; and the partition (521) is fixedly connected to the inner wall of the heat exchange tube (52).

8. A process for treating electroplating wastewater, comprising the electroplating wastewater treatment device according to any one of claims 1 to 7, and employing the following method: a. Sending the electroplating wastewater into an adsorption tower (1) for adsorption by activated carbon; b. passing the adsorbed electroplating wastewater into a sedimentation tank (2) to further precipitate and treat cyanide and chromium compounds; c. passing the electroplating wastewater into an ion exchange tank (3) for ion exchange; d. passing the electroplating wastewater into the heat exchange tank (4) and pumping the electroplating wastewater into the heat exchanger (5) for heat exchange; e. The electroplating wastewater with a temperature sufficient for evaporation is passed into the falling film evaporator (6), while the electroplating wastewater with an insufficient temperature is returned to the heat exchange tank (4).

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