What is a Rice Huller?
A rice huller (also known as a rice husker) is a key piece of equipment in the grain processing industry used to remove the husk (outer shell) from paddy rice. It is an indispensable first-step machine in rice processing lines. After hulling, paddy is separated into brown rice and husks, laying the foundation for subsequent whitening processes.
Main Types of Rice Hullers
Currently, rice hullers on the market are mainly divided into the following types:
- Rubber Roll Rice Huller: Uses a pair of counter-rotating rubber rolls to squeeze and rub the paddy, separating the husk from the brown rice. This is the most widely used huller type today.
- Pneumatic Rice Huller: Uses pneumatic control systems to precisely regulate roll pressure, achieving automatic and uniform feeding for more stable dehusking performance.
- Emery Disk Rice Huller: Uses friction between abrasive disks for dehusking, suitable for specific rice varieties.
Working Principle of Rubber Roll Rice Hullers
Rubber roll rice hullers are the most commonly used paddy dehusking equipment in grain processing plants. The working principle is as follows:
Squeezing and Rubbing Action: The core components are a pair of rubber rolls rotating in opposite directions at different peripheral speeds (one fast roll and one slow roll). When paddy evenly enters the nip between the two rolls from the feed hopper, it is subjected to squeezing and rubbing forces. Since the bonding force between the husk and the brown rice is weaker than the husk's own strength, the husk is torn open, achieving dehusking.
The Key Role of Peripheral Speed Difference: The peripheral speed difference between the fast and slow rolls (typically 2.0-2.5 m/s) generates the rubbing force essential for dehusking. Zhejiang Lianggong Machinery's rubber roll rice hullers ensure this speed difference remains in the optimal range through precision-designed transmission systems, effectively improving hulling efficiency while reducing broken rice rates.
Air Separation System: After hulling, the mixture (brown rice, husks, and unhulled grains) passes through an air separation system. Using the difference in specific gravity between husks and brown rice, airflow removes the lighter husks while heavier brown rice and unhulled grains continue downward.
Advantages of Pneumatic Rice Hullers
Pneumatic rice hullers add pneumatic control systems to traditional rubber roll hullers, offering these advantages:
- Automatic Roll Pressure Adjustment: Adapts to different rice varieties and moisture levels through automatic pressure regulation
- More Uniform Feeding: Air-assisted feeding ensures consistent material layer thickness in the nip zone
- Roll Protection: Prevents damage to rubber roll surfaces from hard impurities, extending service life
- Easy Operation: High degree of automation reduces manual intervention
Importance of Rice Hullers in Rice Processing
The hulling process is the first critical step in rice processing, and its quality directly affects subsequent whitening results and finished rice quality:
- Hulling rate should reach 85%-92%; too high increases broken rice, too low affects yield
- Brown rice broken rate should be controlled below 3%
- Grain content in husk should be less than 0.5%
Zhejiang Lianggong Machinery Technology Co., Ltd. has focused on rice huller R&D and manufacturing for 30 years. Our rubber roll and pneumatic rice hullers are widely used in rice processing enterprises domestically and internationally, earning customer trust with stable performance and excellent hulling results.
If you are looking for reliable rice huller equipment, please call 0575-87335525 or visit our website for more product information.
