Tech Team · Kintek Solution

Cryogenic grinding, also known as cold grinding, is a process that involves cooling materials to extremely low temperatures using liquid nitrogen before grinding them into fine particles. This method is particularly useful for heat-sensitive materials, as it prevents the loss of volatile components and preserves the quality of the original product. The process begins with cleaning and feeding the material into a hopper, followed by cooling in a helical screw conveyor where liquid nitrogen is sprayed. The material is then crushed between studs and cones, and the final product is collected in a bin. The vaporized nitrogen is recycled, making the process energy-efficient.

Key Points Explained:

1. Purpose of Cryogenic Grinding:

   • Preservation of Quality: Cryogenic grinding is designed to maintain the quality of heat-sensitive materials by preventing the loss of volatile components and heat-sensitive constituents.
   • Energy Efficiency: The process is more energy-efficient compared to traditional grinding methods because the material becomes brittle at low temperatures, making it easier to grind.

2. Process Overview:

   • Material Preparation: The material is first manually cleaned and then fed into a hopper.
   • Cooling: The material enters a vibratory feeder and is directed into a helical screw conveyor where liquid nitrogen is sprayed to cool the material.
   • Grinding: The cooled and embrittled material is crushed between studs and cones.
   • Collection: The ground product exits through an optional test sieve and is collected in a bin at the bottom.
   • Nitrogen Recycling: Vaporized nitrogen is recycled using a centrifugal blower, making the process more sustainable.

3. Advantages of Cryogenic Grinding:

   • Fine Particle Size: The process results in fine particles with the same quality as the original material.
   • Reduced Heat Damage: By keeping the material at low temperatures, the process avoids the heat damage that can occur in traditional grinding methods.
   • Lower Energy Consumption: The brittleness of the material at low temperatures means less energy is required for grinding.

4. Applications:

   • Herbs and Spices: Cryogenic grinding is ideal for grinding herbs and spices, which often contain volatile oils and heat-sensitive compounds.
   • Pharmaceuticals: The process is used in the pharmaceutical industry to grind active pharmaceutical ingredients (APIs) without degrading their quality.
   • Plastics and Polymers: Cryogenic grinding is also used for grinding plastics and polymers, which can become sticky and difficult to grind at room temperature.

5. Equipment and Consumables:

   • Liquid Nitrogen: The primary consumable in cryogenic grinding, used to cool the material.
   • Grinding Mill: Specialized equipment designed to handle the low temperatures and brittle nature of the material.
   • Conveyor System: A helical screw conveyor is used to transport the material while it is being cooled.
   • Collection System: Includes sieves and bins for collecting the final ground product.

6. Considerations for Purchasers:

   • Material Compatibility: Ensure that the material to be ground is suitable for cryogenic grinding.
   • Equipment Cost: Consider the initial investment in specialized grinding equipment and the ongoing cost of liquid nitrogen.
   • Energy Efficiency: Evaluate the energy savings compared to traditional grinding methods.
   • Product Quality: Assess the impact on the quality of the final product, particularly for heat-sensitive materials.

By understanding these key points, purchasers can make informed decisions about whether cryogenic grinding is the right process for their specific needs and materials.

Summary Table:

Aspect	Details
Purpose	Preserves quality, energy-efficient, prevents heat damage
Process	Material cleaning → Cooling with liquid nitrogen → Grinding → Collection
Advantages	Fine particles, reduced heat damage, lower energy consumption
Applications	Herbs, spices, pharmaceuticals, plastics, polymers
Equipment	Grinding mill , helical screw conveyor, liquid nitrogen, collection system
Considerations	Material compatibility, equipment cost, energy efficiency, product quality

Ready to explore cryogenic grinding for your materials? Contact us today to learn more!