In sodium chloride electrolysis applications such as sodium hypochlorite generators and water treatment disinfection equipment, the rectifier is the core power supply device that converts alternating current (AC) into stable direct current (DC). Its performance directly affects electrolysis efficiency, product quality, and equipment lifespan.

Sodium chloride electrolysis (especially sodium hypochlorite preparation) is an electrochemical process that generates a strong oxidizing disinfectant by electrolyzing a brine solution. This process places unique technical requirements on the rectifier power supply:

1. Strict Current Stability: The electrolysis reaction rate is directly related to the current density. According to the working principle of sodium hypochlorite generators, the electrode reactions in the electrolytic cell require precise DC control: chlorine gas is evolved at the anode (2Cl⁻ - 2e → Cl₂↑), and hydrogen gas is evolved at the cathode (2H⁺ + 2e → H₂↑), ultimately producing sodium hypochlorite. Current fluctuations directly lead to unstable chlorine production, affecting the consistency of the disinfectant concentration.
2. Specific Voltage and Current Matching
   Typical sodium hypochlorite generators use 12V-24V low-voltage DC power supply, but have high current requirements (ranging from tens to thousands of amperes depending on production capacity). The rectifier must be able to operate stably under low voltage and high current conditions, which places higher demands on the equipment's heat dissipation design and component selection.
3. Harmonic Suppression and Power Factor Optimization
   The rectifier is a key power supply regulation device in the electrolysis system. Electrolysis production has extremely high requirements for current stability; harmonic components can cause grid current instability and reduce the power factor. When selecting a rectifier, priority should be given to modulated rectifiers with multi-phase rectification and phase-shifting functions, increasing the number of rectified pulses to offset the harmonic effects.

Five Core Selection Factors

I. Voltage Regulation Range and Accuracy
The voltage regulation range for the sodium chloride electrolysis process needs to be controlled between 50% and 100%.

1. Continuous and Smooth Voltage Regulation: Phase-controlled voltage regulation is achieved using thyristors or self-saturating reactors, allowing for smooth control at the phase angle of the silicon rectifier element's conduction.
2. Automatic Current Stabilization Function: Equipped with a PI-regulated PWM control circuit, it automatically maintains the set current value when the grid voltage fluctuates or the electrolytic cell load changes.

II. Rectification Method and Pulse Number

1. Multiphase Rectification is Superior: Rectifier transformers with 48 pulses or higher can significantly reduce the ripple coefficient.
2. Advantages of High-Frequency Switching Power Supplies: Switching power supplies using MOSFET or IGBT modules can achieve an efficiency of 95-98%, resulting in more stable current operation.

III. Cooling and Protection System
The sodium chloride electrolysis environment is humid and involves exothermic reactions. Therefore, the rectifier must possess the following features:

1. Forced air cooling or water cooling: Ensures controllable component temperature under high current conditions.
2. Multiple protection mechanisms: Including temperature protection, overload protection, short circuit protection, and phase loss protection.
3. Corrosion-resistant design: The protection rating is recommended to be no less than IP54, and the circuit board must undergo three-proof treatment.

IV. Efficiency and Energy Consumption Indicators

1. Conversion Efficiency: A high-quality rectifier should have an efficiency of over 95% to reduce long-term operating costs.
2. Low Salt and Power Consumption: For a generator equipped with a high-efficiency rectifier, the salt consumption is 3-4.5 grams per gram of effective chloride produced, with a power consumption of 4-5 watts.

V. Intelligent Control Level Modern sodium hypochlorite generators employ fully automated PLC control. The rectifier should possess:

1. Remote monitoring interface: RS485 or Ethernet communication, connected to a SCADA system
2. Real-time parameter display: Visualized data such as voltage, current, power, and electrolysis efficiency
3. Fault self-diagnosis: Early warning of problems such as scaling in the electrolytic cell and electrode aging

Choosing a suitable sodium chloride rectifier is essentially choosing a power supply solution deeply matched to the electrolysis process. The core elements are stable DC output, excellent harmonic suppression, and reliable protection design. Users are advised to prioritize high-efficiency equipment with multi-pulse rectification, automatic current stabilization, and intelligent monitoring functions based on actual chlorine production needs, and to fully consider the corrosive characteristics of the electrolysis environment to ensure that the rectifier and generator work together for more than 10 years.