Taobo bean grading machine is specialized screening equipment that utilizes multiple vibrating screens with varying aperture sizes to precisely sort beans based on particle size and diameter. Often used in conjunction with air-screen gravity cleaners and destoners, it not only removes impurities—such as stalks, soil clods, broken beans, and fine sand—but also separates the raw grain mixture into large, medium, and small grades of finished product. Meeting the grading standards required for supermarkets and canned goods exports, it is an essential piece of equipment for specialty grain processing plants aiming to produce premium, graded beans.

Working Principle of the Grading machine

✅ The motor drives the entire sieve box to undergo a steady, reciprocating linear vibration. Material is evenly distributed across the multi-layered sieve surfaces from the feed end, undergoing stratification and sorting based on mesh aperture sizes:

✅ Top layer (large-aperture mesh): Retains oversized impurities—such as large soil clods, long bean pods, and coarse stalks—which are discharged separately as waste;

Middle layer (standard mesh): Retains uniform, high-quality commercial beans, which are discharged as the primary finished product;

✅ Bottom layer (fine-aperture mesh): Allows fine bean fragments, fine soil/sand, weed seeds, and shriveled/undersized grains to pass through for separate collection;

✅ Rubber cleaning balls are positioned beneath each mesh layer; during vibration, they automatically strike the mesh to prevent bean debris and soil from clogging the apertures, ensuring continuous and smooth screening operations.

South Korean facilities processing grains, gift sets, sesame oil, and sauces—handling ingredients such as small black beans, soybeans, red beans, mung beans, white and black sesame seeds, perilla seeds, brown rice, Job's tears, chickpeas, and coffee beans—require air-screen gravity cleaners, grading screens, and destoners to remove stones, moldy or shriveled kernels, dust, and debris.

✅  Precise grading by particle size to boost product premiums

Legumes (small black beans, adzuki beans, soybeans, red kidney beans, chickpeas, etc.)

Markets, food processing plants, and gift-set producers demand high uniformity in bean size; mixed-size batches can only be sold in bulk at low prices. Multi-layer screening systems can sort beans into large, medium, and small grades while removing shriveled or deformed ones. This standardized sizing ensures a premium appearance for vacuum-packed gift sets, canned goods, and fermented sauces, commanding significantly higher purchase prices.

✅  Automatic screen cleaning prevents clogging, enabling continuous 24-hour mass production

Rubber bouncing balls are installed beneath each screen layer to continuously strike the mesh, automatically clearing away sediment, bean particles, and rice bran; this eliminates issues such as mesh blinding or screening failure. There is no need for frequent shutdowns for manual screen cleaning, making the system ideal for high-volume, continuous factory processing and significantly boosting overall production efficiency.

✅  Versatile and efficient, with simple material switching and high equipment utilization.

By simply swapping screens with different aperture sizes, the machine can flexibly process various types of beans, rice, brown rice, and mixed grains, eliminating the need to purchase separate dedicated screening units for beans and rice. It features a compact footprint and can be integrated with a bucket elevator, air-screen gravity cleaner, destoner, and polisher to form a complete production line, making it suitable for facilities of various sizes.

Grading machine used in South Korean bean processing are designed to achieve precise sorting—thereby boosting product value—and to meet the standardization requirements for Korean-style sauces and mixed-grain gift sets. Key features include the early removal of stones and impurities to protect downstream equipment, low-breakage operation that preserves the beans' structural integrity and nutritional value, and fully automated screening that reduces labor costs. The machinery complies with South Korean food hygiene standards and handles a wide variety of bean types, making it an essential piece of pre-processing equipment for bean exports and deep processing.