In the process of electrolyzing salt to produce caustic soda, a significant amount of hot and humid chlorine gas is generated. Efficient cooling and drying methods are essential to utilize this gas effectively. Direct water spray cooling leads to environmental pollution, chlorine gas loss, and unfavorable working conditions. Indirect cooling with various materials like graphite, glass, ceramic, and plastic coolers has encountered issues such as corrosion, cracking, and aging. However, the use of titanium coolers has shown promising results due to their exceptional corrosion resistance in high-temperature and humid chlorine gas environments.
Cooling with Titanium
Extensive testing has revealed that titanium exhibits remarkable corrosion resistance when exposed to hot and humid chlorine gas. The corrosion rate of titanium in this environment is only 0.0025mm per year. These findings have led to the adoption of titanium coolers in the chlor-alkali industry, offering advantages like shortened cooling and drying processes, reduced chlorine loss, decreased environmental pollution, and improved stability of compressed gas and high drying.
International Adoption
Russia pioneered the use of titanium-made chlorine gas coolers and pipes for transporting wet chlorine gas in 1963. The United States' Allied Chemical Company also replaced graphite with titanium coolers in chlor-alkali production, achieving better performance and efficiency. In China, the first titanium cooler was manufactured in 1965, and since 1973, numerous titanium tubular coolers have been successfully employed in chlor-alkali plants across the country, including Shanghai, Tianjin, Beijing, Liaoning, and Guangdong.
Benefits of Titanium Pumps and Valves
In chlorine production through membrane electrolysis and mercury electrolysis, titanium pumps offer the most economical solution for handling potassium hypochlorite and sodium hypochlorite. An exemplary case is the use of a titanium pump by Georgia-Pacific, a US-based company, to handle a salt solution at 85°C, containing NaCl crystals and free chlorine. The titanium pump has demonstrated a remarkable service life of up to 10 years, showcasing its long-term reliability and cost-effectiveness.
The utilization of titanium equipment, such as coolers, pumps, and valves, has revolutionized industrial applications involving chlorine gas. The exceptional corrosion resistance of titanium in high-temperature and humid environments has resulted in improved efficiency, reduced environmental impact, and enhanced operational stability. This advancement in materials and equipment has significantly contributed to the development of the chlor-alkali industry worldwide.
