What is the working principle of the grain seed wind screen cleaner?

The grain seed air screening machine separates impurities and inferior seeds from grain seeds by combining two core technologies: wind sorting and mechanical screening. Its working principle can be divided into two key links, which work together to complete the cleaning process:

1. Initial Air Cleaning: Removing Light Impurities
After the equipment is started, the fan generates a steady airflow (the air volume can be adjusted using the damper). When the seed mixture to be cleaned (including seeds, dust, straw fragments, shriveled seeds, etc.) enters the feed inlet, it is first separated by airflow.
Lighter impurities (such as dust, straw fragments, and shriveled seeds) are carried away by the airflow and discharged through the impurity discharge port.
Full seeds and heavier impurities (such as pebbles and clods of earth) fall due to gravity and enter the screening stage.

Second, Multi-layer Screening: Size Separation
The falling seeds and heavy impurities enter a vibrating screen (typically composed of multiple layers of screens with varying apertures). The screen generates high-frequency vibrations via an eccentric shaft or a vibrating motor, achieving a second separation:
The first screen (with a larger aperture) separates impurities larger than the seeds (such as large clumps of soil and straw fragments), which are then discharged from the sides of the screen.
The second screen (with an aperture matching the seed size) allows the seeds to fall through the screen holes, leaving slightly larger foreign crop seeds or impurities on the screen surface.
The third screen (optional, with a smaller aperture) separates fine impurities smaller than the seeds (such as sand and broken seeds), further purifying the seeds.

Through a combined process of “wind separation to remove light impurities” and “screening to remove large and small impurities,” the wind screen cleaner can increase seed purity to over 99%, while retaining plump, high-quality seeds, providing high-quality raw materials for sowing or processing. Its core advantage lies in its integration of multiple physical separation principles, enabling efficient processing of large seed batches while adapting to the characteristics of different crops.