TAOBO gravity separator is a specialized precision sorting machine that utilizes differences in material density (specific gravity), a vibrating deck, and vertical airflow to achieve separation. Unaffected by particle size, it is specifically designed to separate materials of similar dimensions but differing weights. Serving as a core piece of equipment for advanced sorting—following initial air-screen and grading-screen processes—it resolves industry challenges where standard screens fail to remove shriveled beans, moldy beans, or stones of similar size. It is widely used in export processing plants for crops such as mung beans, black beans, red beans, sesame seeds, and pigeon peas.

Vietnamese small-grain mung beans are characterized by their diminutive size; field-run batches often contain similarly sized shriveled or immature beans, insect-damaged grains, and fine red sandy soil, making the raw material prone to mold during the rainy season. A precision gravity separator effectively stratifies and removes lightweight moldy grains and fine grit, ensuring the beans remain vibrant green and intact. This process guarantees high quality for applications such as paste production and bean sprouting, meets export standards for China, Japan, and South Korea, and increases the unit export price.

Working Principle of the Gravity Separator

✅  Uniform Material Feeding and Fluidized Stratification

Material is evenly spread across an inclined vibrating deck. A fan at the base continuously delivers a uniform, low-pressure upward airflow, causing the entire material layer to enter a state of slight suspension and fluidization.

Denser, plump, and intact seeds settle at the bottom layer due to their weight; insect-damaged, moldy, shriveled, or hollow seeds—being lighter—float in the upper layer.

✅  Vibration-Induced Counter-Flow Separation

The deck undergoes small-amplitude reciprocating vibration and features a non-slip "fish-scale" surface pattern:

Plump, heavy beans in the bottom layer flow downward along the incline and exit through the finished product outlet;

Light, defective beans in the upper layer move upward against the flow, guided by the deck's surface pattern, and are discharged separately through the rejects outlet;

Stones and high-density soil clumps—similar in size to the beans but heavier—cling tightly to the deck surface, climb upward against the flow, and exit through the heavy impurity outlet.

✅ Adjustable Airflow Settings

Airflow can be reduced for small Vietnamese mung beans and increased for large-grain pigeon peas or kidney beans; this ensures stable stratification and prevents the loss of good beans into the reject stream.

Advantages of the Gravity Separator

✅  Remove moldy grains to mitigate food safety risks in foreign trade

Moldy and insect-damaged (hollow) beans are lighter in weight and can be completely separated. This reduces the risk of excessive aflatoxin levels, ensures compliance with import inspection standards in markets such as China, South Korea, the Middle East, and India, and prevents shipment rejection or price devaluation.

✅  Suitable for multiple crops with easy switching

By simply fine-tuning airflow and deck inclination, the machine can process mung beans, small black beans, adzuki beans, pigeon peas, sesame seeds, red kidney beans, and more. Its multi-crop capability lowers equipment procurement costs.

✅  Configurable into a complete production line

It can be integrated with air-screen gravity separators, grading screens, destoners, and polishers to form a comprehensive cleaning and processing line, suitable for various specialty grain processing plants in Vietnam, Mozambique, South Korea, and beyond.

Processing plants in Vietnam typically handle mung beans, red beans, soybeans, and pigeon peas simultaneously; switching between materials requires only minor adjustments to air pressure and table inclination, eliminating the need to purchase multiple separate precision sorting machines. The unit features a compact footprint and can be integrated with air-screen cleaners, grading screens, and polishers to form a complete mung bean cleaning line, making it suitable for the facility layouts of both small and large-scale processing plants.