Abstract

The aim of present work is improving the performance of the crop residues shredder by study of some engineering factors concerning the performance of the affecting tool. The items to achieve the aim of the present study are:(1) Evaluation of shredder performance before development(2)Manufacture of cutting knives from local materials.(3)Shredder performance analysis in cutting of cotton stalks (4)Shredder performance analysis in cutting of rice straw (5)Cost analysis of cutting operation. From the above mentioned study, it can recommend the following points for farmer or producer or user following the mentioned order has all the choices according to the prevailing production conditions;1The proper selection of new material leads to decrease the sharp edge angle of modified knives to 20 o degree without deformation. 2Maximum cutting efficiency for cotton stalks was 86.4 % at 1mm clearance distance.,20 o degree knife edge angle and 1600 rpm cutting drum speed.3Minimum fuel consumption rate for cotton stalks was 2.48 L/h at 1 mm clearance distance, 20 o degree knife edge angle. 4Maximum machine production for cotton stalks was 1.4 ton/h at following factors:5 mm clearance distance, at 20 o degree knife edge angle and 1600 rpm cutting drum speed.5Maximum cutting efficiency for rice straw was 45.6 % at 1 mm clearance distance.,20 degree knife edge angle ,1600 rpm cutting drum speed. 6Minimum fuel consumption rate for rice straw was 3.51 L/h at 1 mm clearance distance, 20 degree knife edge angle.7-Maximum machine production for rice straw was 0.99ton/h at following factors: 1 mm clearance distance.,20 degree knife edge angle 1600 rpm cutting drum speed.8-Cutting operation cost is 27.5 L.E./h. *Prof. of Agric. Eng , Fac. of Agric., Cairo Univ. **Senior Res., Agric. Eng. Res.Inst.(AEnRI) Agric. Research Center Researcher at Water Relations and Field Irrigation Department, National Research Center – Dokki – GizaEgypt. Role of agricultural engineering in environmental and sustainable development for the valley and delta areas: 1555 1571 FARM MACHINERY AND POWER The 17 th . Annual Conference of the Misr Society of Ag. Eng., 28 October, 2010 1556 INTRODUCTION he quantity of crop residues in Egypt was determined to be about 25.4 million Mg /year, beside 4 million Mg/year of horticultural according to the statistical survey of the Egyptian Ministry of Agriculture (2009)(in Arabic). A bad effect on economic, environment, public health and others, can be done by increasing crop residues quantities of all kinds and forms if doesn’t be treated in suitable ways. The mechanical treatment by cutting or grinding for crop residues are the most important and primary step should be done to make it great useful. In Egypt there are three types of cutting machines for cutting crop residues and the most current models are cylinder-type cutterheads but there are some disadvantages of shredder are: 1-Low cutting efficiency.(percentage of weight of suitable length for compost and fodder). 2Low productivity. 3High fuel consumption. The aim of present work is improving the performance of the crop residues shredder by study of some engineering factors concerning the performance of the affecting tool. Hashish (1981) stated that increasing fodder production from residues such as cotton stalks by crushing or milling them alone as roughages or together with other fodder materials. In addition, protein substitutes can be added to raise their nutritive value. In addition, the same author determined the lengths of the residues accepted by the animals as 2.54-3.81 cm and sometimes reached 0.52 cm, length. He also mentioned that the equipment remove the outer layers of the stalks which were harmful to the animal. Prasad and Gupta (2005) stated that a knife approach angle of 32 degree was observed to be optimum corresponding to minimum value of energy requirements for cutting maize stalk. Sverker (1987). Showed that a large edge angle will require higher cutting force and more cutting energy. They added that the cutting force linearly increases with the increase in edge angle. Ige and Finner (1976b) stated that the effect of the clearance distance is reduced to that of a simple cantilever beam. Before shearing, the knife usually bends the forge over shear-bar. Mathematically, the energy used for bending the forage is thus super-imposed onto the shearing energy. If the system was assumed to be represented by that of a cantilever beam, this additional energy would be proportional to the clearance distance to the third T FARM MACHINERY AND POWER The 17 th . Annual Conference of the Misr Society of Ag. Eng., 28 October, 2010 1557 power. If it is assumed to be the bending of a plate, where it would be proportional to the clearance distance squared. MATERIAL AND METHODS Material: Shredder machine: Specifications of the shredder machine are as follow: a) Cutting cylinder: 70 cm long and 50 cm diameter skeleton cylinder with two cutting drum and sixteen cutter knives. b) The knives and the Countershear: The knife and the countershear are two active elements of a cutting device ( chopping cylinder), with the knife being the primary active component. Knife dimensions are 35 cm long, 7 cm wide, 0.9 cm Thickness edge angle 30 degree and Countershear dimensions are 82 cm long , 6 cm wide and 0.9 cm thickness. c) Feeding tray: 120 cm long, 105 cm and 72 cm near and front width, respectively, and 20 cm side wall height. d) Feeding opening : 61 cm width x 19 cm height. Methods: Machine production: Time of chopping was measured by means of a stopwatch to determine the machine production in Mg/h (Arif, 1999). Fuel consumption: The fuel tank was filled to full capacity before and after each trial. A graduated cylinder was used for each test trial to measure the amount of refueling. The rate of fuel consumption was calculated as follow: Fuel consumption = Amount of fuel consumption, L/ Time elapsed, h, L/h ( 1 ) (Imbabi, 2001) Cutting efficiency, ηc: The cutting length of final product is an important parameter to evaluate the performance of cutting process. Where, the suitable cutting length that can be used to produce the compost and the forage is in the range of 0< Lc < 50 mm. There are standard sieves used for segregation of a specific mass, Sb , from the chopped production to several weights, having cutting length 0< Lc < 50 mm. Consequently, the cutting efficiency can be calculated as following. ηc = Sa/ Sb x 100...(2) Where: Sb is the mass of the chopped production before segregation, g; FARM MACHINERY AND POWER The 17 th . Annual Conference of the Misr Society of Ag. Eng., 28 October, 2010 1558 Sa is the mass of the chopped production after segregation of cutting length 0< Lc < 50 mm, g. (Habib, 2002 ). RESULTS AND DISCUSSION 1. Evaluation of Shredder Performance before Development Table (1): Shredder performance for cotton stalks before development at 30 0 knife edge angle and 4 mm clearance distance: