Manufacturing a Mechanical Unit for Grain Packing

This research aims to design a suitable machine for packing paddy grains mechanically to; reduce grains production costs and decrease the wasted time. An innovated new design was fabricated locally to combine various operations in one self-propelled machine from picking grains from the ground packing it into sacks by a screw elevating system, measuring the accurate needed weight tie sacks under the control of the forward and packing speeds which, synchronizing with grains layers density. The bio-engineering parameter from saving the operators from rising dusts were achieved by fixing a dust protection divider to keep dusts and weed seeds away to purify the species quality. The study included three experimental variables were as follows; four speed ratios between the winnower and screws (Sr) of (0.102, 0.123, 0.143 and 0.164) (1: 9.78, 1: 8.15, 1: 6.98 and 1: 6.11) with three levels of screw pitches (Ip) of (6, 7.5 and 9 cm) and three levels of paddy layers thickness (Lth) of (5, 10 and 15 cm), while measurements included: first; the efficiencies of [picking grains (ηp), volumetric capacity (ηv) and machine efficiency (Me)], second; the grains damage percentage (Gd) and the machine productivity (P) third; the fuel (F) and energy consumption (Pr), fourth; the rising dusts (D) from the machine Fifth: the machine economic costs (C). The most important results included that: the maximum value of the picking grains efficiency (Qp) was 91.34 %, for Sr 0.164 at 9 cm of the Ip and 15 cm of the L th. While, the maximum value of the conveyor screws volumetric efficiency (ηv) was 93.58 % for the same factors. Besides the optimum value of the machine efficiency (Me) was 91.11 % for Sr 0.164 at 6 cm of the Ip and 5 cm of the L th. Also, the highest machine productivity (P) value reaches 1.57 ton/h for Sr 0.164 at 9 cm of the Ip and 10 cm of the L th. The maximum consumed energy (Pr) was 1.26 Kw.h/ton for Sr 0.102 at 9 cm of the Ip and 15 cm of the L th. Nerveless, the maximum value of the packing machine rising dusts (D) was 5.18 mg/m3 for Sr 0.164 at 9 cm of the Ip and 15 cm of the L th. Where, the optimum value of the machine operating cost (C) was 16.94 L.E/h for Sr of 0.102 at 6 cm of the Ip and 5 cm of the L th. Studying the costs and benefits indicated that; the proposed machine can decreases the costs of packing from (25 to 17 L.E/h) as about 30 % cost reduction ratio. The internal rate of return (IRR) after considering depreciation, alternative chance costs, the amount costs of fuel and lubricants, and the rental rate calculated found 17 L.E/ h.  The internal rate of return (IRR) with release year was calculated found 32%. This rate is visible compared with the current interest rate of 16% due to the capital return which was about 3 years.