Caustic soda Falling film concentrator

Caustic soda Falling Film concentrator: 

The Caustic soda falling film concentrator is an important piece of equipment widely used in the chlor-alkali industry, primarily for cooling and concentrating sodium hydroxide (caustic soda). Its structural design aims to provide effective heat transfer and fluid dynamics characteristics, ensuring safe operation in high-temperature and highly corrosive environments. Below is a detailed introduction to the structure of the Caustic soda falling film concentrator:

1. Overall Structure
   • Inner Tube: Made of pure nickel, size is OD.112*3.5*L. it has excellent corrosion resistance and is specifically designed to withstand sodium hydroxide.
   • Outer Tube: Typically constructed from carbon steel, the outside diameter is 133.5mm. providing structural support and strength for the falling film tube. The thickness and diameter of the outer tube are selected based on design requirements to ensure safety and durability.
2. Heating Coils
   • Position: The heating coils are located around the outer tube, outside diameter is 21mm. typically arranged in a spiral or circular layout surrounding the outer tube.
   • Function: They heat the liquid inside the inner tube by transferring heat, usually utilizing circulating water or steam as the heating medium. This structure increases the temperature of the liquid, reduces its viscosity, and promotes flow and reaction rates.
3. Liquid Flow Path
   • Falling Film Flow: Sodium hydroxide liquid flows through the inner tube, forming a falling film that creates a thin film on the tube wall, increasing the contact area with the heat exchange medium and enhancing heat exchange efficiency.
   • Flow Design: The inner tube is typically designed to be vertical or inclined, facilitating the formation of falling film flow along the tube wall, ensuring higher heat transfer efficiency.
4. Sealing and Connections
   • Sealing Structure: The space between the inner and outer tubes is sealed with high-performance sealing materials to prevent the leakage of corrosive media. Connection points utilize welding or threaded connections to ensure the stability and safety of the structure.
   • Inlet and Outlet Pipelines: Dedicated inlet and outlet pipelines are set up for feeding and discharging sodium hydroxide liquid, while also connecting to the heating coil’s heat medium inlets and outlets.
5. Control System
   • Temperature Sensors: Installed in the heating system to monitor the temperature of the liquid in the inner tube, ensuring operation within preset ranges.
   • Flow Meters: Used to monitor liquid flow, adjusting heating and flow conditions to ensure stability and efficiency in the production process.