DEVELOPMENT OF MECHANICAL-SYSTEM TO PRODUCE ANIMAL FEED FROM RICE STRAW

Abstract

The aim of present research is to develop a machine, which was cutting the residues to supply two units - the ftrst to mix the additive (urea, molasses and minerals), and the second to add this mixture to the rice straw in this time to get a good distribution. To realize this target, the following stages were planned: (1) Study some characteristics of rice straw (length - diameter - moister content) which affect the chopping operation. (2) Selecting a common chopping machine distinguished of high productivity and simple design.(3) Testing the chopping machine to determine productivity and cutting length.(4) Combine a dissolved unit to mix the additives (urea - minerals - molasses) and joint this device with the chopper machine to add this solution to rice straw during cutting. (5) Testing dissolved unit to determine mixing speed and mixing time. (6) Evaluation of the mechanical system technically and economically. The performance of both of chopping and mixing operations was evaluated and the results can be summarized as follow: Chopping macbine:(l)The chopper productivity was increased while the rotor speed was increased and the clearance decreased. (2)The highest chopper productivity was occurred 600 kg/It at rotor speed 1650 rpm, and tern clearance between fixed knife and movable knives. (3)The percentage of cutting length (tern or less) was increased while the rotor speed increased and decreasing the clearance. In addition, it was neglectfui while the clearance was J mm and the rotor speed was 1450 rpm. (4)The percentage of length of t 0 em and more increasing wi>ilc the rotor speed was 1450 rpm and clearance was 3mm, but it was decreasing at 1650 rpm rotor speed and 1 mm clearance. (S)The percentage offavorite cutting length was from 2 em to 8 em was occurred at rotor speed 1650 rpm and 1 mm knife clearance. Mixer machine: a) Mixture evaluation:(l)The quality and homogeny of mixture were tested by evaluating the ratio of urea in the mixture. (2)The ratio of urea increased by increasing of mixer rotor speed. (3)The ratio of urea was increased through increasing of the mixing time from 5min to 10 and 15 min. (4)The best ratio of urea are increasing near the bottom of tank (from 0 to 25em) more than the medium (from 25 to 50 em) or the top (from 25 to 80 em). (S)The best ratio of urea were at mixer rotor speed 300 rpm, and 15min. duration time of mixer nearly of the tank. b) Distribution evaluation:The best percentage of crude protein was occurred at treated the rice straw samples by 5 % urea. As crude protein was 6.2, 4.9 and 3.6%.while riee straw treated by 5, 3 and 1% urea, respectably. Economic Evaluation:The cost for p ucing one ton of treated rice straw was 7.8 LE compared with the manual mixture (10.93 LE) and the machine provided to realize economic performance by Internal Rate of Return (IRR) and Net Present Value (NPV). In addition, the total investment of this machine can be pain back through only two years.