Saeed AgaAzizi; Mansor Rasekh; Yousef Abbaspour Gilandeh; Mohamadhosein Kianmehr
Abstract
Wild oat (Avena fatua) is the most common weed of wheat fields. Given that the presence of even small amounts of wild oat in the wheat grain mass may lead to a sharp drop in the quality of flour produced, separation of wild oat from wheat will increase the purity of the seed and enhance the economic ...
Read More
Wild oat (Avena fatua) is the most common weed of wheat fields. Given that the presence of even small amounts of wild oat in the wheat grain mass may lead to a sharp drop in the quality of flour produced, separation of wild oat from wheat will increase the purity of the seed and enhance the economic value of the crop. In present study, some physical properties of wheat and wild oat, including geometric properties, gravity properties, frictional properties and initial moisture content were determened. A gravity separator - equipped with some tools to adjust five parameters: air flow rate, frequency of oscillation, amplitude of oscillation, longitudinal slope and latitudinal slope of the table - was used to separate wild oats from wheat grain mass. The effects of these parameters were studied to achieve maximum separation of wild oat from wheat mass. Statistical analyses were performed in two factorial experiments in a completely randomized design. Also, using dimensional analysis, a dimensionless dimensional parameter V/aω was obtained (where v is air speed, a is oscillation and ω is oscillation frequency), which was effective in evaluating the effect and reducing the number of parameters. The results showed significant differences (1%) in moisture content, mass and particle density, boundary velocity and interaction between grain type and friction surface between two grain types. Also, the results indicated that the maximum separation of wild oats from wheat (70.47%) was obtained when the air flow rate was 6 m/s, the oscillation was 5 mm, the oscillation frequency was 395 cycl/min,, and the longitudinal slope and latitudinal slope were 2.5° and 1.5°, respectively.
R. Rahimi; M. H. Kianmehr; S. Reza Hassan-Beigi; Payam Zarafshan
Abstract
One of the methods of using livestock exhaust is compressing and pelletting it, which causes facilitation of transportation, reduction of odor and gradual release of nitrogen. For manure pelleting, extruder and disk pelleting are used. Since the stones existing materials in the stored manure cause damage ...
Read More
One of the methods of using livestock exhaust is compressing and pelletting it, which causes facilitation of transportation, reduction of odor and gradual release of nitrogen. For manure pelleting, extruder and disk pelleting are used. Since the stones existing materials in the stored manure cause damage to the pelletting apparatus, so the removal of the stone from the manure before the processing is necessary. In this research, with the aim of separation the rock from the manure, a gravity separator was designed and fabricated. The performance of the device was evaluated by changing the three slope parameters of the material separator plates, manure moisture content and the size of the stone and manure dimensions The changed level was for 10, 15 and 20 ° slopes of separators, 10, 30 and 50% of the moisture content of manure, and for the particle size of less than 10, 10 to 20 and 20 to 50 mm. The maximum device separation efficiency of the stone from the manure was 76.81% at 10 ° slope, 50% moisture content and a particle size less than 10 mm.
Abstract
Composting livestock manure and municipal solid waste is an appropriate method for waste management in order to stabilize organic wastes. The low specific mass of compost causes problems in transportion and storage activities and increases the costs. In this study some parameters affecting the pellets ...
Read More
Composting livestock manure and municipal solid waste is an appropriate method for waste management in order to stabilize organic wastes. The low specific mass of compost causes problems in transportion and storage activities and increases the costs. In this study some parameters affecting the pellets production was investigated. Parameters considered were: particle size (1 and 2 millimeter), pellet moisture content (25, 35 and 45 percent) and kneading length (1, 2 and 3 meter). Results showed that the specific density of pellets produced under both levels of particle size, increased with increasing the Length of kneading at all levels. Interaction effect of moisture content and kneading length on the rate of fractured pellets showed that, the maximum amount of force was (556.32N) which belonged to treatment with (moisture content of 35% and length of kneading of 3 m). Also the interaction effect of particle density and length of kneading showed that maximum toughness value was (1.03 MJ/m3) which belonged to particle density of 1mm and kneading length 3 m.
Abstract
The optimal use of rotary seed coater needs the knowledge of the physical properties and the behavior of seed motion in rotary drum. One of the most important parameter in these equipments is the rotational speed of the drum which seeds have rolling mode. In this research a new method was used for measuring ...
Read More
The optimal use of rotary seed coater needs the knowledge of the physical properties and the behavior of seed motion in rotary drum. One of the most important parameter in these equipments is the rotational speed of the drum which seeds have rolling mode. In this research a new method was used for measuring these properties that was based on the motion of seeds in a less than 50% filled rotating drum. Firstly the angle of repose of three types of seed (vetch, wheat and tomato seed) with different shape was measured with different methods and the values obtained were compared. Then, the lower and upper angle of repose were also measured by rotary drum. At the final step, the rotational speed of the drum were gradually increased from 0 to 100 rpm and the speed of the drum which the seed rolling mode of motion began and ended was measured. The results showed that the shape of the seeds has a great impact on the type of their motion in the rotating drum and it was obtained that the vetch seeds had the widest speed range with rolling mode of motion (from 1 to 65 rpm). However, this range for tomato seeds is from 8 to 40 rpm and for wheat seeds from 6 to 49 rpm. The increase of filling degree from 25% to 40%, the rolling mode of motion for all of seeds began and ended sooner.
