The Design And Experimental Study Of The Collecting Device Of The Pneumatic Grassland Locust Trapping Machine

The pneumatic grassland locust trapping machine is a new kind of plant protecting machine which adopts physics method to prevent and control grassland locust. Aiming at the problem that the said machine is inefficient in locust collecting function. An experimental study was conducted to the collection device .First of all the physical characteristics of locust was on-the-spot investigated and the air stream velocity for suspension was tested .Then an innovated design of the collection device was completed and two type of blocking elements were designed :The collecting effectiveness of the two type of blocking element and the influence of the air stream velocity at the suction port ,the shape of the blocking plate ,and the position of the blocking plate on the collection function were approached .Based on the analysis of flow field and the distribution state of the air stream velocity in the collection chamber ,a performance test for the collection device was carried out .and the testing result indicates that the plane blocking plate is the suitable to this collection device ,while the bended blocking plate is an ideal blocking element .The flow field and the air stream velocity distribution appeared to be optimum when the No.2 blocking plate shape at the first section R1=400,θ1=75°, second section R2=300,θ2=35°, third section R3=100,θ3=60°and placed it at the position of 230mm apart from the center of collection chamber and the air stream velocity is 16m/s at the suction part .The testing result is verified to be sound by the experiment of dry hot pepper and the collecting rate is 49.8% for plane blocking plate and 97.4% for bended blocking plate .The achievement of this study may provide a theoretical basis for the design of collection device of pneumatic grassland locust trapping machine.