Silver electrolytic refining uses crude silver as the anode. Direct current from the electrolytic rectifier cabinet is passed through an electrolytic cell containing silver nitrate electrolyte, causing the crude silver anode to dissolve and purer silver to deposit on the cathode. This is one of the main methods of silver refining. The silver electrolytic rectifier equipment is a key piece of equipment in the silver electrolytic refining process, and its compatibility greatly affects the quality and power consumption cost of silver electrolysis. A complete set of rectifier equipment includes a rectifier cabinet, digital control cabinet, rectifier transformer (installed inside the cabinet), DC sensors (installed inside the cabinet), etc. It is usually installed indoors near the electrolytic cell, cooled by pure water, and has an input voltage of 380V, etc.
Introduction to Thyristor Rectifier Equipment for Silver Electrolysis
I. Applications
This series of rectifier cabinets is mainly used for different types of rectifier equipment and automated control systems in the electrolysis of non-ferrous metals such as aluminum, magnesium, manganese, zinc, copper, and lead, as well as chloride salts. It can also be used as a power supply for similar loads.
II. Main Cabinet Features
1. Electrical Connection Type: Generally selected based on DC voltage, current, and grid harmonic tolerances, with two main categories: double-star and three-phase bridge, and four different combinations including six-pulse and twelve-pulse connections.
2. High-power thyristors are used to reduce the number of parallel components, simplifying the cabinet structure, reducing losses, and facilitating maintenance.
3. Components and fast-fusing copper busbars use specially designed circulating water circuit profiles for optimal heat dissipation and extended component lifespan.
4. Component press-fitting employs a typical design for balanced and fixed stress, with double insulation.
5. Internal water pipes use imported reinforced transparent soft plastic tubing, resistant to both hot and cold temperatures, and with a long service life.
6. Component radiator faucets undergo special treatment for corrosion resistance.
7. The cabinet is fully CNC machined and powder-coated for an aesthetically pleasing appearance.
8. Cabinets are generally available in indoor open, semi-open, and outdoor fully sealed types; cable entry and exit methods are designed according to user requirements.
9. This series of rectifier cabinets adopts a digital industrial control trigger control system to enable the equipment to operate smoothly.
Voltage Specifications:
16V 36V 75V 100V 125V 160V 200V 315V
400V 500V 630V 800V 1000V 1200V 1400V
Current Specifications:
300A 750A 1000A 2000A 3150A
5000A 6300A 8000A 10000A 16000A
20000A 25000A 31500A 40000A 50000A
63000A 80000A 100000A 120000A 160000A
Introduction to Silver Electrolysis Power Supply Silver electrolytic power supplies are generally small, constant current adjustable DC power supplies. They can use either thyristor rectification or high-frequency DC power.
Taking the matching rectifier cabinet: KGHS-1000A/36V as an example:
I. Main System Form: Double-star thyristor rectification with balancing reactor.
II. Voltage Regulation Method: Thyristor phase-controlled voltage regulation.
III. Equipment Supply Status (Single Unit)
Serial Number Equipment Name Model Specification Quantity Remarks
1 Thyristor Rectifier Unit KHS-1KA/36V 1 unit
IV. Rectifier Cabinet Control and Protection:
4.1 Rectifier Cabinet Pure Water Cooling: The rectifier elements are water-cooled. The main cooling water pipe is a stainless steel pipe. Each cabinet has one inlet and one outlet pipe. All water circuits are connected using rubber-lined reinforced pipes. The water circuits must be able to withstand a 30-minute test at 0.1 MPa water pressure without leakage, and the pipes must be easy and quick to disassemble.
4.2 Main circuit overvoltage protection.
4.3 Thyristor element commutation overvoltage RC absorption protection.
4.4 Overcurrent protection and overload alarm.
4.5 Over-temperature protection.
4.6 Under-pressure protection.
4.7 Feedback disconnection fault protection. When the current feedback signal is open-circuited, the current stabilization control system automatically switches to open-loop operation.
Functional Description
◆ Small Dummy Load: A section of heating element is connected to replace the actual load, ensuring a DC current of 10-20A when the output is at rated DC voltage.
◆ Intelligent Thermal Redundancy Control System: Two CNC controllers are interconnected via thermal redundancy ports, coordinating control in parallel without any control contention or exclusion. Seamless switching between master and slave controllers.
If the master controller fails, the redundant controller automatically and seamlessly switches to become the master controller, truly achieving dual-channel thermal redundancy control. This greatly improves the reliability of the control system.
◆ Seamless Master/Redundancy Switching: Two ZCH-6 control systems with mutual thermal redundancy can be manually configured to determine which controller acts as the master and which as the slave. The switching process is seamless.
◆ Redundancy Switching: If the master controller fails due to an internal fault, the redundant controller automatically and seamlessly switches to become the master controller.
◆ Pulse Adaptive Main Circuit: When a small dummy load is connected to the main circuit, and the voltage feedback amplitude is adjusted within the range of 5-8 volts, the ZCH-6 automatically adjusts the pulse start point, end point, phase shift range, and pulse distribution sequence to make the pulse phase shift adaptive to the main circuit. No manual intervention is required, making it more accurate than manual tuning.
◆ Pulse Clock Selection: By selecting the number of pulse clock points, the pulse can adapt to the main circuit phase and correctly shift phase.
◆ Pulse Phase Fine-tuning: Through pulse phase fine-tuning, the pulse can be precisely aligned with the main circuit phase shift, with an error ≤1°. The fine-tuning value range is -15° to +15°.
◆ Two-Group Pulse Phase Adjustment: Changes the phase difference between the first and second groups of pulses. The adjustment value is zero, and the phase difference between the first and second groups of pulses is 30°. The adjustment value range is -15° to +15°.
◆ Channel 1F is designated as one group of current feedback. Channel 2F is designated as two groups of current feedback.
◆ Automatic Current Sharing: The ZCH-6 automatically adjusts based on the current feedback deviation without manual intervention. ◆ Seamless Switching: Power output remains unchanged during switching.
◆ Emergency Stop Function: Shorting the FS terminal to the 0V terminal immediately stops ZCH-6 from sending trigger pulses. Leaving the FS terminal floating allows trigger pulse sending.
◆ Soft Start Function: When ZCH-6 is powered on, after self-test, the output slowly climbs to the setpoint output. The standard soft start time is 5 seconds. Customizable time is adjustable.
◆ Zero Return Protection Function: When ZCH-6 is powered on, after self-test, if the setpoint is not zero, no trigger pulse is output. Normal operation resumes when the setpoint returns to zero.
◆ ZCH-6 Software Reset: ZCH-6 is reset by executing a software program command.
◆ ZCH-6 Hardware Reset: ZCH-6 is reset via hardware.
◆ Phase Shift Range Selection: Range 0～3. 0: 120°, 1: 150°, 2: 180°, 3: 90°
◆ Permanent Parameter Saving: Adjustments to the control parameters of the ZCH-6 CNC controller are saved in RAM and will be lost during power outages. To permanently save the adjusted control parameters: ① Set bits 1-8 of SW1 and SW2 to OFF, OFF, OFF, OFF, OFF, ON, OFF, OFF to enable saving;
② Enable the permanent parameter saving function; ③ Set bits 1-8 of SW1 and SW2 to OFF to disable saving.
◆ PID Parameter Auto-tuning: The controller automatically measures load characteristics to obtain the optimal algorithm for the load. This is more precise than manual adjustment. For special loads where load characteristics are highly variable and related to load conditions, PID tuning must be manual.
◆ PID Controller Selection:
PID0: Dynamic fast PID, suitable for resistive loads.
PID1: Medium-speed PID, with excellent overall automatic adjustment performance, suitable for resistive-capacitive and resistive-inductive loads.
PID2 is suitable for controlled objects with high inertia, such as voltage regulation of capacitive loads and current regulation of inductive loads.
PID3 to PID7 are manual PID controllers, allowing manual adjustment of the P, I, and D parameter values.
PID8 and PID9 are customized for special loads.
