Design Orchards Wastes Shredder for Smallholders Using Ansys

Abstract

Compost has the main role of the organic farming in Egypt, its demand rapidly increased. But for the small scale of the orchards small holders it is a problem, many of Egyptian orchards are small farms (<=0.5 ha), suffering from the lack of small size shredders. Wastes particle size has an impact on the compost industry. Therefore the main object of this project was to design and manufacture a shredder, produces uniform raw material proper for making compost in a short time. This is investigation was done in the National Research Centre, Egypt with the cooperation with scientists from Qingdao Agricultural University, China. This prototype shredder could control the thickness of the recycled orchards wastes according to the needs of compost producers to recycle orchards wastes (max. 5 cm diameter). The shredder machine consists of frame, hopper, cutting shaft, cutting support, 2 pulleys, belt, and Ac motor 3 phase. The main part is the cutting shaft and the cutting support which give the ability of controlling the size of shredded waste. Ansys program was used to analysis the shear stress, total deformation, equivalent stress (Von Mises) to choose the proper material of the cutting shaft to do such operation. Choosing the material of the shaft and the cutting knifes was analyzed using Ansys 18.1, the maximum shear stress, equivalent stress and displacement deformation on the wood bulk were obtained using stainless steel material, followed by cast iron then structure steel, for that the recommended material for the shaft was structure steel and for the cutting knifes was stainless steel. The cutting support is flexible to have the desired thickness of the cut material, but the study focused only on 2 mm thickness according to the compost expertise requirements. the shredder machine operation was to feed the orchards wastes (tree branches max. 5 cm diameter) to a hoper at 45^o angle between the adjustable support (protruding), and the shaft with sharp cutting fixed knives, to cut the wastes depended on the shear stress between the wood and the blades, then the cut pieces will grumbling down by the shaft acceleration and gravity in the bottom of the shredder to be collected later.