الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 173 |  |  |
| | | from | 173 | | |
Abstract
This investigation research aims to study some factors affecting the design of rice-straw bales chopper to overcome the operation problems such as un-continuous feeding rate of rice straw to a cutting unit, and the rice-straw cutting size. The rice-straw bales chopper was modified and tested in Rice Mechanization Center, Meet El-Deeba, Kafr El-Sheikh Governorate during two sequence years of 2018 and 2019. The rice-straw bales chopper after modification consists of frame, feeding-mechanism (feeding conveyor and feeding claws), chopping unit (cutting drum and chopping drum), double solid-concave, outlet duct, 20-hp electrical motor and power-transmission unit. The field experiments were conducted to determine the suitable operation factors to obtain suitable straw lengths for the animal feeding, compost process and other purposes. The studied factors were type of knives (free, fixed curved and “free + fixed curved”), chopping-drum speeds of 1450, 1750, 2050 and 2350 rpm (34.16, 41.23, 48.3 and 55.37 m/s), feeding-mechanism speeds of 0.26, 0.31, 0.35 and 0.42 m/s and rice straw bale moisture-contents with average of 15.6, 18.2 and 21.3 %. The optimum operation factors were chopping-drum speed of 2350 rpm (55.37 m/s), type of cutting knives of “free + fixed curved”, feeding-mechanism speed of 0.26 m/s and rice-straw bale moisture contents with average of 15.6 %. The results data after using the optimum factors were: straw cutting length-average about 3.31 cm, straw cutting-length percentage for categories of < 3 and 3 - 6 cm of 70.85 and 22.95 %, machine capacity of 1.06 Mg/h, power requirements about 6.43 kW and specific energy of 6.09 kW.h/Mg. Also, the operation and production costs of 19.71 L.E./h and 18.67 L.E./Mg were obtained at optimum conditions.