Design And Experiment Of Shunt-hedging Multi-channel Automatic Sand Sampler

The process of soil erosion that under the action of wind in the surface soil of fine material, soil nutrients and organic matter of wind erosion, transport and deposition is an important environmental problem in the north of china. The sand sampler is an important device for studying soil erosion,which can be used to test the flow characteristics of surface sand and study the movement laws of surface sand.In recent years, the foreign advanced wind erosion test equipments about soil erosion have entered the domestic field. A typical equipment which called SUSTRA sand sampler is developed by German company UGT.It is equipped with automatic data acquisition system that can be real-time weigh and record the sand sample, which breaking the traditional way of manual sampling. But in the fierce wind, the high data fluctuation affects the reliability of wind erosion data. Therefore, This paper propose a theory that the hedging of split gas can reduce the flow rate to solve the problem for strong wind disturbance, and develop a new type of sand sampler called a shunt-hedging multi channel type sand sampler through theoretical calculation, methods of numerical simulation and field test. The test results of the performance of the falling velocity and sand collection were also carried out. The results showed that the proposed shunt-hedging sand sampler showed a high deceleration and sand collecting performance. The deceleration magnitude of desilting-port was 95.12%, which not only ensured the effective separation of wind-sand inside a sand sampler, but also mitigate the shock of desilting-port airflow to the cantilever weighing sensor under strong wind. This sampler consistent with the basic requirements of designing a sand sampler. The average sampling efficiency was 91.7%in 9m/s to 18m/s wind speed, and the equal dynamic performance was 91.91%, which could better satisfy the needs of wind tunnel experiments and erosion observation.