Automatic dosing control device for reducing hexavalent chromium in electroplating wastewater
By using a visual recognition system to identify the color states of hexavalent and trivalent chromium ions, the problem of ORP controllers being greatly affected by pH values is solved, thus achieving automation and cost savings in electroplating wastewater treatment.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GUANGDONG HONGYAO ENVIRONMENTAL PROTECTION ENG CO LTD
- Filing Date
- 2025-07-25
- Publication Date
- 2026-06-26
AI Technical Summary
In existing electroplating wastewater treatment, the ORP controller is greatly affected by pH value, making it difficult to accurately control the dosage of chemicals and increasing treatment costs.
A visual recognition system is used to replace the ORP controller. By identifying the colorimetric state of hexavalent and trivalent chromium ions under acidic conditions, the dosage of reducing agent can be controlled, thus avoiding strict control of pH value.
It enables the process to meet requirements at low pH levels (≤4), reduces the use of acid or alkali, lowers processing costs, and improves automation and ease of equipment maintenance.
Smart Images
Figure CN224411527U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of water treatment equipment, specifically to an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater. Background Technology
[0002] The chromium plating process in the electroplating industry generates acidic wastewater containing hexavalent chromium. Since hexavalent chromium is a highly toxic pollutant, it must be treated to meet standards at the workshop discharge point before being discharged into other wastewater for further treatment.
[0003] Existing hexavalent chromium wastewater treatment processes typically employ an ORP controller for auxiliary control. During the treatment process, the pH of the wastewater is generally adjusted to 2.5–3 in a pH adjustment tank using a pH controller. Then, a reducing agent is added to the reduction reaction tank using an ORP controller to initiate the reduction reaction. The ORP is generally controlled at 230–270 mV, and the reaction time is 30 minutes. After the hexavalent chromium is fully reduced, it is discharged through the workshop effluent.
[0004] Because ORP values are greatly affected by pH, under normal circumstances, the lower the pH, the higher the ORP value. ORP controllers lack specificity and are significantly influenced by pH, making accurate dosage control difficult. Therefore, existing processes must strictly control the pH within a precise range, inevitably leading to the addition of large amounts of acid or alkali to adjust the wastewater pH, thus increasing treatment costs. Utility Model Content
[0005] The purpose of this invention is to address the problems existing in the prior art by providing an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater. This device uses a video recognition system to replace the ORP controller, eliminating the need for precise control of the wastewater pH value.
[0006] To achieve the above objectives, the present invention adopts the following technical solution:
[0007] An automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater includes a pH adjustment tank, a reduction reaction tank, a sampling pump, a video recognition system, a control assembly, and a dosing device. The reduction reaction tank is connected downstream of the pH adjustment tank. The sampling pump is connected to the reduction reaction tank via a sampling pipeline, and the video recognition system is connected downstream of the sampling pump. The video recognition system is then reconnected to the reduction reaction tank via a return pipeline. The video recognition system is connected to the control assembly, and the control assembly is connected to the dosing device, enabling the control assembly to control the dosing device based on signals from the video recognition system.
[0008] Furthermore, the dosing device includes a dosing pump and a dosing tank; the dosing pump is connected between the dosing tank and the reduction reaction tank via a pipeline.
[0009] Furthermore, the dosing device is a solid feeder.
[0010] Furthermore, the pH adjustment tank is equipped with a pH sensing module, which is connected to the control assembly.
[0011] This invention relates to an automatic dosing control device for hexavalent chromium reduction in electroplating wastewater. It replaces the original ORP controller with a video recognition system. Based on the different color development states of hexavalent and trivalent chromium ions under acidic conditions, the system uses the color of the water sample captured by the video recognition system and the actual hexavalent chromium content detected in the sample to control the dosage of the reducing agent. Under this device, the process requirements are met when the pH is ≤4, essentially eliminating the need for acid adjustment and significantly reducing costs. Attached Figure Description
[0012] Figure 1 This utility model provides a schematic diagram of the structure of an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater, which uses a dosing pump.
[0013] Figure 2 This utility model provides an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater, which uses a solid feeder for dosing. Detailed Implementation
[0014] The technical solution of this utility model will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0015] Example 1
[0016] like Figure 1 As shown, this utility model provides an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater, comprising a pH adjustment tank 1, a reduction reaction tank 2, a sampling pump 3, a visual recognition system 4, a control assembly 5, and a dosing device 6. The reduction reaction tank 2 is connected after the pH adjustment tank 1. The sampling pump 3 is connected to the reduction reaction tank 2 through a sampling pipe 31, and then connected to the visual recognition system 4. The visual recognition system 4 is then reconnected to the reduction reaction tank 2 through a return pipe 32. The visual recognition system 4 is connected to the control assembly 5, and the control assembly 5 is connected to the dosing device 6, so that the control assembly 5 controls the dosing device 6 according to the signal from the visual recognition system 4.
[0017] This device uses a visual recognition system 4 instead of an ORP controller. Wastewater from the reduction reaction tank 2 is first drawn into the visual recognition system 4 via sampling pipe 31 by sampling pump 3 as a water sample. The visual recognition system 4 performs visual recognition on the sample, which is then returned to the reduction reaction tank 2 via return pipe 32. Based on the different color states of hexavalent and trivalent chromium ions under acidic conditions, the visual recognition system 4 captures and identifies the color of the water sample, establishing a database of color and hexavalent chromium content, thereby identifying the actual hexavalent chromium content of the water sample. The control assembly 5 outputs a control signal to control the dosing device 6 to add the corresponding amount of reducing agent.
[0018] This device is relatively stable due to pH value. The dosage can be flexibly adjusted according to the content of hexavalent chromium. As long as the pH value is ≤4, the process requirements can be met. Under normal circumstances, no additional acid is required, which can save costs.
[0019] Furthermore, ORP controllers are relatively inconvenient to maintain, requiring 2-3 days for debugging and calibration, and have a lifespan of only about one year. Avoiding the use of ORP controllers can effectively reduce equipment maintenance costs.
[0020] like Figure 2 As shown, specifically, the dosing device 6 includes a dosing pump 61 and a dosing tank 62; the dosing pump 61 is connected between the dosing tank 62 and the reduction reaction tank 2 via a pipeline. This configuration is suitable for situations where the reducing agent is a solution. Alternatively, as another preferred structure, the dosing device 6 can be a solid feeder 63, which is suitable for situations where the reducing agent is a solid.
[0021] Preferably, the pH adjustment tank 1 is equipped with a pH sensing module, which is connected to the control assembly 5. The pH sensing module serves as a safety device; in extreme cases, if the pH value of the wastewater exceeds 4 due to external factors, the pH sensing module sends a signal to the control assembly 5, causing the control equipment to stop and trigger an alarm.
[0022] This utility model provides an automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater. It uses a video recognition system to identify the color of the wastewater and detect the actual hexavalent chromium content, thus flexibly controlling the dosage of the reducing agent without requiring strict pH control. This simplifies the process, virtually eliminates the need for acid addition, saves costs, and offers a high degree of automation. It also avoids the use of ORP controllers, which require debugging and have a short lifespan, saving on equipment maintenance costs.
[0023] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.
Claims
1. An automatic dosing control device for the reduction of hexavalent chromium in electroplating wastewater, characterized in that: It includes a pH adjustment tank, a reduction reaction tank, a sampling pump, a visual recognition system, a control assembly, and a dosing device; the reduction reaction tank is connected after the pH adjustment tank; the sampling pump is connected to the reduction reaction tank through a sampling pipeline, and then connected to the visual recognition system, which is then reconnected to the reduction reaction tank through a return pipeline; the visual recognition system is connected to the control assembly, and the control assembly is connected to the dosing device, enabling the control assembly to control the dosing device based on signals from the visual recognition system.
2. The automatic dosing control device for hexavalent chromium reduction in electroplating wastewater according to claim 1, characterized in that: The dosing device includes a dosing pump and a dosing tank; the dosing pump is connected between the dosing tank and the reduction reaction tank via a pipeline.
3. The automatic dosing control device for hexavalent chromium reduction in electroplating wastewater according to claim 1, characterized in that: The dosing device is a solid feeder.
4. The automatic dosing control device for hexavalent chromium reduction in electroplating wastewater according to claim 1, characterized in that: The pH adjustment tank is equipped with a pH sensing module, which is connected to the control assembly.