Herbal raw materials are highly temperature-sensitive — the frictional heat generated by conventional pulverizers during high-speed comminution causes significant loss of essential oil components in volatile spices such as peppermint, fennel, and cardamom, directly impacting the aroma intensity and product stability of finished mouth freshener formulations. WANROOETECH’s liquid nitrogen cryogenic pulverizer cools the feedstock to its embrittlement state prior to grinding, achieving ultrafine comminution within an adjustable temperature range of 0°C to -196°C, with output particle sizes covering 40–300 mesh (food/pharmaceutical grade), making it suitable for temperature-sensitive herb and spice processing applications.

What Is a Liquid Nitrogen Pulverizer?

Liquid Nitrogen Pulverizer (Cryogenic Pulverizer / Freezing Pulverizer): A machine that cools feedstock to its embrittlement temperature using liquid nitrogen before conveying it into the grinding chamber for high-speed pulverization. Under cryogenic conditions, material brittleness increases significantly, requiring less grinding force and generating substantially lower frictional heat — thereby preserving natural aroma, color, and active constituents.
Cryogenic Grinding System Configuration: Liquid nitrogen storage tank → feedstock pre-cooling screw conveyor → grinding chamber (high-speed impeller) → induced draft fan → cyclone classifier and powder collector. The entire system forms a closed-loop circuit, maximizing cold source utilization and reducing liquid nitrogen consumption.

Cryogenic Grinding of Herbs and Spices: Why Temperature Control Is Critical

Volatile aromatic constituents (essential oils) in herbal raw materials volatilize or oxidize rapidly when exposed to temperatures above a certain threshold. In conventional high-speed pulverizers operating at ambient temperature, frictional heat can cause localized temperatures to exceed 80°C instantaneously, resulting in significant aroma loss, color browning, and — in oil-rich feedstocks — material adhesion to chamber walls and equipment clogging.
The specific value of cryogenic grinding for herb processing is demonstrated in the following aspects:
The entire grinding process is maintained at low temperature, drastically reducing volatile aroma loss and yielding finished products with fragrance profiles closer to those of natural raw materials
Feedstock pulverized in an embrittled state produces more uniform particle size distribution and higher fine powder yield
Oil-bearing herbs (clove, cinnamon, etc.) do not exude oil during grinding, reducing equipment cleaning frequency
The inert nitrogen atmosphere provides explosion-proof and anti-oxidation properties, meeting food safety requirements for spice products
Controllable discharge temperature ensures stable product coloration without secondary oxidation induced by heat exposure

WANROOETECH Cryogenic Pulverizer — Technical Specifications

Official specifications of the WANROOETECH Liquid Nitrogen Cryogenic Pulverizer, validated for food, herbal, and pharmaceutical materials:

For mouth freshener and herb/spice processing applications, the universal liquid nitrogen cryogenic pulverizer is recommended. This model has been verified to process oil-bearing food raw materials such as chili powder and traditional Chinese/western medicinal herbs, with an output particle size range of 40–300 mesh that closely aligns with the process requirements of herbal powder production.

Frequently Asked Questions

What Herbal and Spice Raw Materials Can the Liquid Nitrogen Pulverizer Process?
The official application scope of the WANROOETECH liquid nitrogen pulverizer covers various oil-bearing / sugar-containing food products (such as chili powder), ultrafine grinding of traditional Chinese and western medicinal herbs, as well as thermoplastic and rubber materials. For mouth freshener raw materials, common herbs including peppermint, fennel, cardamom, cinnamon, clove, and licorice all fall within the applicable range. Fresh raw materials with high moisture content are recommended to undergo drying pretreatment prior to cryogenic grinding.

What Micron Range Does 40–300 Mesh Output Particle Size Correspond To?
Based on standard conversion, 40 mesh corresponds to approximately 425 μm, 100 mesh to approximately 150 μm, 200 mesh to approximately 75 μm, and 300 mesh to approximately 48 μm. Mouth freshener formulation powders typically require 80–200 mesh (75–180 μm), a range covered by the WANROOETECH liquid nitrogen pulverizer in food / pharmaceutical mode. Specific particle size is adjusted via rotor speed and classifier wheel settings.

What Equipment Is Included in the Complete Liquid Nitrogen Pulverizer System?
The standard configuration comprises: liquid nitrogen storage tank (supplied by customer) → feed screw conveyor → grinding main unit → induced draft fan → cyclone powder collector, with the cold source forming a closed-loop circuit returning to the grinding chamber to maximize liquid nitrogen utilization and reduce operating costs. If post-processing equipment such as vibrating screen classifiers is required, it can be incorporated into the complete line solution.

Process video