Sodium hypochlorite disinfection equipment

　 Introduction to Sodium Hypochlorite

The sodium hypochlorite generator is a type of water treatment equipment used for disinfection and sterilization. It uses brine as the raw material and produces a sodium hypochlorite solution through an electrolysis process.

　　Sodium hypochlorite is a strong oxidizing agent and disinfectant, produced by membrane-free electrolysis of a dilute solution derived from commonly available, low-cost industrial salt or seawater. To ensure that the sodium hypochlorite remains fresh and highly active, thereby guaranteeing effective disinfection, this system generates the sodium hypochlorite on-site and immediately doses it for use. Compared with chlorine and its compounds, sodium hypochlorite exhibits equivalent oxidizing and disinfecting properties.

　　Scope of Application

　　This device is primarily used for the treatment of bacteriologically contaminated wastewater in hospitals and cyanide-containing electroplating effluent. It can also be employed for the disinfection of swimming pool water, domestic drinking water, and domestic sewage, as well as for the disinfection of environments in food processing plants, medical devices, tableware and drinkware in restaurants and public canteens.

　　Equipment Features

　　(1) The sodium hypochlorite generator is a modular unit in which salt dissolution, dilute brine preparation, dosing and metering, and sodium hypochlorite recirculation all take place within a single tank, resulting in low capital investment, minimal footprint, and flexible installation.

　　(2) The generator adopts a tubular, internally cooled, unipolar, series-connected configuration. The anode is made of titanium with a ruthenium dioxide coating, offering low overpotential and long service life. Under normal operating conditions, each unit can operate continuously for 200–300 hours per run. The sodium hypochlorite generation process employs a diaphragm-type natural circulation system, resulting in high salt utilization, high current efficiency during electrolysis, high sodium hypochlorite yield, low energy consumption, and reduced operating costs.

　　Working Principle

　　1. The sodium hypochlorite generator is of a modular design: dilute brine is metered and fed into the electrolytic cell, where a silicon rectifier supplies DC power to the anode and cathode, driving the electrolysis that produces sodium hypochlorite.

　　2. Sodium hypochlorite consumption: 4.0–4.2 kg; power consumption: 4.3–4.5 kW.

　　3. A saline solution contains several ions, including Na+ and H−. According to electrolysis theory, when electrodes are immersed in the solution and a suitable voltage is applied, the ionic mobility and electrode reactions give rise to electrical conduction. Under these conditions, anions such as Cl− and OH− migrate toward the anode, while cations such as Na+ and H+ migrate toward the cathode; at the respective electrodes, discharge occurs, leading to redox reactions that produce the corresponding products.

　　4. The electrolysis of a saltwater solution can be represented by the following reaction equation: NaCl → Na⁺ + Cl⁻

　　5. Anodic electrolysis: H2O → H+ + OH-; 2Cl- → Cl2↑ + 2e-. Cathodic electrolysis: 2H+ + 2e- → H2↑.

　　6. In a diaphragmless electrolytic cell, the electrolyte and the electrolysis product—hydrogen gas—both remain within the same electrolytic cell; however, as the hydrogen gas escapes from the solution, it exerts a stirring effect that induces a series of chemical reactions between the electrolysis products at the two electrodes. The reaction equations are as follows:

　　2NaCl + 2H₂O → 2NaOH + H₂↑ + Cl₂ 2NaOH + Cl₂ → NaClO + NaCl + H₂O

　　7. In diaphragmless electrolysis of brine, the overall reaction equation is obtained by summing the two reactions given above: NaCl + H2O + 2F → NaClO + H2↑, where F is the Faraday constant for electrolysis, with a value of 26.8 ampere-hours, or 96,487 coulombs.

　　8. The sodium hypochlorite generator consists of an electrolytic cell, a silicon rectifier control cabinet, a brine dissolution tank, a cooling system, and associated PUVC piping, valves, water ejectors, flow meters, and other components. A 3–4% brine solution is introduced into the electrolytic cell, a 12 V DC power supply is connected, and the electrolytic current is adjusted to generate sodium hypochlorite through electrolysis. The generated disinfectant solution is then drawn in and mixed by a water ejector for delivery, or metered by a dosing pump and delivered via a mixer.

Water Tank Self-Cleaning Disinfectant

Ozone disinfection equipment

Water Tank Self-Cleaning Disinfectant

Ozone disinfection equipment

Related Cases