Legume Gravity Separator

Legume Gravity Separator

Shijiazhuang Xinlu Technology Co., Ltd. - Technical Overview of the Legume Gravity Separator

In the processing of various legumes—such as chickpeas, lentils, beans, and peas—the Gravity Separator is an indispensable machine for achieving a high-purity product that meets stringent market standards. Legumes, after harvesting, often contain a mixture of mature, well-developed seeds and a percentage of immature, shriveled, frost-damaged, or insect-bored seeds. While these defective seeds may pass through sizing screens because they share similar dimensions with sound seeds, they differ significantly in their specific weight. The Legume Gravity Separator is specifically designed to exploit this difference in density, providing a highly effective method for quality upgrading that mechanical sizing alone cannot accomplish.

The separation process is both mechanical and pneumatic. The machine features a vibrating, inclined deck with a porous surface. An adjustable fan forces a uniform stream of air upwards through this deck. The legume seeds are fed onto the lower section of this deck. As the deck oscillates with a combination of horizontal and vertical movements, the incoming seeds are spread into a thin, uniform layer. The upward air current fluidizes this layer, reducing inter-particle friction and allowing the seeds to stratify according to their density.

The densest, healthiest seeds, which are typically well-filled and have a high nutritional value, quickly settle to the bottom of the bed, directly onto the deck surface. The kinematic action of the deck's vibration then transports these premium seeds uphill, to the highest discharge point. Lighter contaminants, including immature seeds, badly damaged seeds, sand, and small stones of similar size but lower density, are buoyed by the air and remain on the surface of the fluidized bed. These low-specific-gravity materials flow downhill along the inclined deck and are discharged at the lower reject outlet.

A critical capability of the gravity separator is its handling of a "middlings" fraction. This consists of seeds that are of intermediate density—neither the best nor the worst. The machine's adjustable side tilt allows the operator to guide this fraction to a separate, central discharge spout. This feature provides great flexibility; the middlings can be recirculated back through the separator for another pass to recover more good product, or they can be bagged as a lower-grade commodity, maximizing overall yield and economic return.

The applications for a Legume Gravity Separator are extensive. For food-grade legumes, it significantly enhances the visual appeal and cooking quality of the final product by removing stones and defective seeds that would not soften properly during cooking. For seed production purposes, it is one of the most reliable methods for increasing the germination rate and seedling vigor of a legume seed lot, as low-density seeds are often non-viable. The machine from Shijiazhuang Xinlu Technology Co., Ltd. is built for durability to handle the continuous processing of abrasive materials. Key components like the deck mesh, the rubber seals for the air chamber, and the drive mechanism are designed for easy maintenance and replacement, ensuring minimal downtime and consistent, reliable operation in a demanding legume processing facility.