The process principle of liquid nitrogen low-temperature crusher is to use liquid nitrogen as a cooling medium (temperature as low as -196 ° C) to cool the material to its brittle point temperature, making the originally elastic or fibrous material brittle and fragile; Subsequently, the mechanical crushing system crushes the brittle material into small particles through external forces such as impact, shear, or friction, while the temperature control system accurately maintains a low-temperature environment to prevent the material from degrading or losing its original characteristics due to heat generation. The entire process includes three core steps:
Liquid nitrogen cooling and embrittlement: Liquid nitrogen is pressurized from a storage tank and supplied to the crushing chamber. After spraying, it quickly vaporizes and absorbs heat (the vaporization process absorbs about 199.3 kJ/kg of heat). The material is rapidly cooled to the embrittlement point (such as the critical low temperature of rubber, plastic, or biomaterials), achieving molecular structure embrittlement.
Mechanical crushing process: Brittle materials enter a high-speed rotating impeller or blade system and are crushed through repeated impacts, collisions, and shearing in a closed chamber; The particle size can be adjusted (10-1000 mesh), and qualified particles are separated by a grading wheel. Unqualified materials are circulated back to the chamber for further crushing.
Temperature and nitrogen management: PID control or frequency conversion technology (such as adjusting fan speed) is used, combined with liquid nitrogen recovery devices (such as cyclone return systems), to recycle vaporized nitrogen gas, reduce cold waste, and maintain temperature stability within the set range (error can be controlled to ± 3 ° C), ensuring that material components (such as medicinal activity or food color) are not damaged. This process is suitable for heat sensitive materials such as polymer materials and biomedicine, and has the advantages of low energy consumption, less dust, and high efficiency.