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Diaphragm Chlorine Cell Services

Diaphragm chlorine cells are the world's workhorse in producing chlorine. More chlorine is made in diaphragm cells than in any other technology. This technology is the most popular in North America. The cell operates by placing an asbestos or polymer blended porous diaphragm between the anode (+) and the cathode (-) section of the cell to separate the generated chlorine and hydrogen gases. Separation is required to prevent an explosion.

The salt solution (brine) entering the cell passes through the porous diaphragm and is changed into the caustic soda product. The caustic produced by this cell is therefore weak and laden with salt. An extensive evaporation and salt separation system is required to produce the commercial 50% concentration of caustic soda.

Andritz Automation's personnel have operated, managed, and supported this technology for in excess of 25 years. We have developed specialized tools to assist the diaphragm cell operator. These tools and our generalized services are outlined below:

Specialized Diaphragm Cell Systems and Tools

• Automated Cathode/Anode Washing: The diaphragm in the cell needs to be periodically removed and refreshed; however, it tightly adheres to the cathode screen. Washing the diaphragm off the screen requires a jet of high pressure water. The process is very labor intensive. Andritz Automation and Eltech Systems have jointly developed an automated system to perform this task.
• Automated Diaphragm Depositing: The technique to deposit a fresh diaphragm is frequently "an art form". Slight differences in recipe, temperature, or technique can result in substandard and inconsistent performance. Andritz Automation and Curlin Chlor/Alkali Consultants have developed an automated system for diaphragm depositing that eliminates the variability.

Process Optimization

We are internationally known experts in the following major processing areas of a membrane plant. Published papers and further information are available by clicking on the links.

• Brine Treatment: Although more robust that other cell technologies, diaphragm cells benefit from good quality brine. Andritz Automation can optimize the brine system for reliable production.
• Chlorine Handling: The prevention of corrosion from wet chlorine and the safe compression, liquefaction, and shipping practices are all essential in any type of chlorine plant. Andritz Automation has decades of experience in this area.
• Caustic Soda Evaporation: Diaphragm cells produce only approximately 10% caustic directly in the cell. A large evaporator is required to concentrate the caustic to the required 50% strength. There are a number of tricks in the trade to adequately separate the suspended salt from the finished product for quality improvement. Universal Dynamics can help implement these techniques.
• Safety and Environmental Compliance: Andritz Automation's personnel have won many governmental awards for safety and environmental compliance projects.