Closed-loop nitrogen circulation is a fully sealed recycled inert gas system for powder production lines. It circulates and reuses nitrogen inside the whole process pipeline instead of exhausting nitrogen directly, stably maintaining low-oxygen inert atmosphere throughout powder processing.
Working Principle
- Pre-operation: Use pure nitrogen to purge all air inside mill, classifier, dust collector and pipes, drop oxygen to target level.
- Running status: Keep slight positive pressure inside the whole line to block outside air infiltration.
- Gas recycling: Used nitrogen carrying dust, heat and moisture flows into purification units for dust removal, cooling and dehumidification.
- Re-circulation: Purified clean nitrogen is sent back to the grinding system for repeated use.
- Supplement: Only add a small amount of new nitrogen to make up tiny system leakage loss.
Main System Components
- Sealed full-process production equipment
- Nitrogen purification & cooling module
- Oxygen online monitor
- Pressure regulating unit
- Circulation fan & pipeline
Core Functions
- Prevent flammable powder dust explosion
- Avoid powder oxidation, discoloration and deterioration
- Stabilize oxygen concentration below required standard (such as 2%)
- Greatly reduce nitrogen consumption and cut operation cost
- Control process temperature and humidity to prevent powder agglomeration
Application Range
Widely used in sulfur powder milling, lithium battery material grinding, metal powder processing, chemical fine powder and other easily oxidized & explosive powder production.
Difference from Open Nitrogen Protection
- Open type: Nitrogen is filled and exhausted directly, high consumption, unstable oxygen content
- Closed-loop type: Nitrogen recycled, low consumption, constant low-oxygen environment, higher safety
