Measuring Picking Force of Sunflower Seeds and Prediction of Reasonable Range of Air-Jet Parameters to Remove Sunflower Seeds from the Head

To design a new machine which removes the seeds of sunflowers based on air-jet impingement, picking force of five varieties of sunflower seeds was measured. Effects of the loading rate, sunflower head’s diameter, the location of the seeds on the head and the number of the days after harvesting on picking force of seeds were studied. The tests were conducted 1, 2, 3 and 4 days after harvesting. Also theoretical air-jet impingement forces for four levels of nozzle diameter, four levels of jet temperature and eight levels of pressure of reservoir to which the jet were calculated. With the increase of the sunflower heads’ diameter and the loading rate from 50 to 150 g min-1, the values of the picking force increased. With the increase of the distance between the location of the seeds and the center of the head, the values of the picking force decreased. Comparison between the experimental results and the theoretical calculations indicated that removing the sunflower seeds using nozzles with 2 mm is not possible. Also when the supply pressure is less than 5 bar, nozzles with a 4 mm diameter cannot be used to remove the sunflower seeds from the heads. The results indicate that using a nozzle with a diameter of 6 to 8 mm and pressure of 6 to 8 bar seems to be suitable for separating the seeds from SH, though more studies are required

Effect of air-jet impingement parameters on the removing of sunflower seeds from the heads in static conditions

Due to the success of air-jet in food and agricultural sciences, in order to eliminate a number of problems in mechanical methods of removing sunflower seeds from the head, a new method was invented based on impingement jets.  In fact, the aim of presenting the air-jet impingement method was not to design this simple machine.  But when we started designing the final machine, we realized that we need to take a step back and study the jet parameters in simple and static state.  The effect of the seeds’ location on sunflower head, reservoir pressure, the angle of impingement, nozzle diameter and the distance between the nozzle outlet and the surface of the sunflower head on the removed area of sunflower head in static conditions were examined.  The regions removed by the impingement of the air-jet were photographed and the area of the removed regions was calculated. Response surface methodology was used for designing experiments for all three regions of sunflower head of “Dorsefid” variety.  Based on the obtained results of two varieties, on side, middle and central regions, removing seeds using 30°, 60° and 90° angle of impingement is advised respectively.  The results indicated that the area of the removed regions was increased with the increase of the nozzle diameter and reservoir pressure. Also the removed area increased with the increase of the distance between the nozzle outlet and the surface of the SH at first, but then decreased. The optimal distance between the nozzle outlet and the surface of the SH ranges between 24 to 28 mm

Moisture content on some engineering properties of celery (Apium Graveolens L) seeds

The study was conducted to investigate some physical properties of celery seed at various moisture levels.  The average length, width, thickness and 1000-seeds mass were 0.571, 0.429, 0.295 mm and 0.792 g, respectively, at moisture content of 5.24% (d.b).  Length, width and thickness distributions of the seeds were modeled using Generalized Extreme Value, lognormal and Weibull distributions.  Results showed that to model length of the seeds, lognormal distribution had the best performance while to model the width of the seeds Weibull distribution had the best performance.  True density has increase from 892.02 to 931.42 kg/m3 when the moisture content increased from 5.24% to 20.25% (d.b).  The angle of static friction increased from 28.45 to 39.66°, 25.15 to 34.84°, 19.57 to 27.07° and 16.72 to 19.720° for plywood, rubber, iron and galvanized metal, respectively, as the moisture content increases from 5.24% to 20.25% (d.b).  The pouring angle of repose increased from 34.70 to 39.12°, 33.37 to 36.37°, 30.59 to 33.33° and 27.16 to 29.45° for plywood, rubber, iron and galvanized metal , respectively, as the moisture content increases from 5.24% to 20.25% (d.b).  The Hele-Shaw angle of repose increased from 32.65 to 35.25°, 30.35 to 32.77°, 27.81 to 30.03° and 24.72 to 26.61° for plywood, rubber, iron and galvanized metal , respectively, as the moisture content increases from 5.24% to 20.25% (d.b)

Measuring some physical properties of sunflower (helianthus annus l.) head and modeling dimensions

For 100 sunflower head, maximum and minimum diameters, thickness, height of the ground, and mass of all seeds on sunflower head (SH) for five conventional varieties were measured.  To examine the correlation between maximum SH diameter and minimum SH diameter, SH thickness, SH height from the ground and SH seeds mass, linear regression method was used.  Also SH diameter and SH thickness of four sunflower hybrids varieties were measured.  Log-normal, Weibull and Generalized extreme value (G.E.V) distribution were used in order to model SH diameter and SH thickness distributions of all varieties and hybrids; also, Kolmogorov-Smirnov methods were used for comparison of all probability density.  Results indicated that value of average of dimensions, geometric and arithmetic mean diameter, head height from the ground, and mass of the seeds on each head of Dorsefid and Sirena varieties were more and less than the other varieties, respectively.  For all varieties, there was linear correlation between maximum SH diameter and minimum SH diameters, SH thickness and mass of seeds; while there wasn’t any correlation between SH height and maximum SH diameter.  Results showed that whenever skewness and kurtosis had positive values, Log-normal and G.E.V distribution had good performance and whenever skewness and kurtosis had negative values, Weibull and G.E.V distribution had good performance based on Kolomogrov-Smirnov methods

Physical properties and modeling for sunflower seeds

For designing the dehulling, separating, threshing, sizing and planting machines for sunflower, physical and mechanical properties of sunflower seeds should be known.  In this work some physical properties of three varieties of sunflower seeds, distance between the adjacent seeds on the sunflower head (SH), length, width, thickness, mass of the individual seeds,  1000- seeds mass, and changing these parameters with location of seeds on SH were measured.  Then shape properties, including geometric mean diameter, sphericity, surface area, projected area and volume of the seeds were calculated.  Variations of the shape properties of the seeds on the SH were studied.  Statistical indices for dimensional and shape parameters were calculated.  For Mikhi, Sirena, and Songhori varieties, true and bulk densities, porosity, angle of repose on wood and galvanized surfaces were calculated by using standard methods in the moisture of 9.15, 5.26 and 5.62% (w.b.), respectively.  The distribution of distance between adjacent seeds on SH was modeled by using three continuous statistical distributions namely Normal, two-parameter Log-normal and two-parameter Weibull distribution.  Size and mass of seeds were modeled with two-parameter Weibull distribution.  The parameters of the probability density functions (PDF) were estimated, then evaluated, and the predictive performances of the models were compared.  Log likelihood goodness of fit test was used to test how well different PDFs work for prediction of the distance between seeds on sunflower head, size and mass of seeds.   The results for three varieties showed that when the distance between locations of the seed from center of the sunflower head increased, size, shape properties and mass of seed, increased, too.  The values of true and bulk density, porosity and angle of repose on wood and galvanized surfaces for Mikhi variety were 497.500 kg/m3, 331.027 kg/m3, 33.46% , 25.08° and 22.23°, for Sirena were 580.368 kg/m3, 422.015 kg/m3, 27.28%, 26.80° and 23.86°, and for Songhori were 471.746 kg/m3, 319.346 kg/m3, 32.30%, 24.39° and 21.70° respectively.  Modeling result for the distance between adjacent seeds on SH showed that, Log-normal distribution model fits the empirical probability density well and two-parameter Weibull distribution had worst performance for prediction.  Also modeling result for the distance between adjacent seeds on showed that whenever Skewness and Kurtosis had negative value, Weibull distribution was best fit.  Statistical analyses for dimensional properties and mass showed that in most cases, both Skewness and Kurtosis had negative values.  Therefor for modeling dimensional properties and mass, Weibull distribution was used. Keywords: sunflower seed, normal modeling, two-parameter log-normal modeling, two-parameter Weibull distribution modeling, physical properties

Gamma irradiation effects on physical properties of squash seeds

In order to study the effects of gamma radiation on some physical properties of squash (Cucurbit pepo. L) seed, five irradiation doses (25, 50, 75, 100 and 200 GY) have been used.  Some physical properties, including dimensional properties (length, width, thickness, geometric mean diameter, sphericity, volume, surface area, projected area, flakiness ratio and elongation ratio), mass, 1,000 seeds mass, bulk density, true density and porosity of gamma irradiated squash seeds were measured.  Statistical indices including maximum, minimum, average, variance, skewness and kurtosis, for dimensional properties and mass of the seeds were calculated.  Results revealed a significant raise in hollow seeds number by increasing gamma irradiation dose from 5% for 25 GY to nearly 100% for 100 and 200 GY.  On the other hand, length, width, thickness, mass of single seed, 1,000 seeds mass and porosity showed an increase followed by a decrease with the increasing gamma irradiation dose.  With the increasing gamma irradiation dose, true and bulk densities were found to decrease from 338.41   kg m-3 to 214.01 kg m-3 and 420.16 kg m-3 to 256.12 kg m-3, respectively.  In 100 and 200 GY all seeds were hollow and very small, therefore dimensions and mass of these seeds were not measured. Keywords: gravimetric properties, dimensional properties, squash seeds, irradiation, gamma ra

Gravimetrical and frictional properties of broilers diets

Abstract: Information on physical properties of broiler chickens diets is not available in literatures and such information is important for design and construction of poultry equipments.  Some physical properties of starter, grower and finisher diet of broiler chickens, namely: gravimetrical (bulk density, true density and porosity) and frictional properties (coefficient of friction filling angle of repose, empting angle of repose and pouring angle of repose) were studied.  Effect of height of falling diets to the containers at 150, 250 and 350 mm and volume of the containers at 500, 600, 1,100 and 2,000 mL on bulk density and porosity of diets were studied.  Results indicated that true density of the starter; grower and finisher diets were 1,442.574, 1,512.694 and 1,541.320 kg m3, respectively.  A comparison between the three levels of height of falling for three diets indicated that with increasing height of falling, bulk density were increased and porosity were decreased.  The coefficient of friction of starter, grower and finisher diet on different surfaces changed from 18.033 to 26.743°, 18.083 to 27.193° and 18.293 to 27.570°, respectively.  The values obtained for pouring angle of repose of starter diet on iron, plywood and galvanized surfaces were 34.40°, 36.05° and 30.22°, respectively.  The corresponding values for grower and finisher diets were 38.71°, 39.62°, and 33.72° and 36.66°, 38.21° and 33.62°, respectively.   Keywords: broilers diet, bulk density, true density, coefficient of friction, angle of repos

Some physical properties of almond nut and kernel and modeling dimensional properties

Three main dimensions of nut and kernel of almonds were measured.  Then some dimensional properties of nut and kernel were calculated.  Effect of the moisture content on bulk density, true density, porosity and coefficient of friction of kernels and nuts were studied.  Angle of repose on iron, plywood and galvanized sheet were measured.  Also in order to examine the correlation between two dimensions of kernels and nuts and correlation between one dimension of nuts and similar dimension of kernels, linear and quadratic regression were used.  Length, width and thickness distributions of nuts and kernels were modeled using normal, log normal, Weibull and Generalized Extreme Value distributions.  For modeling other dimensional properties, only Generalized Extreme Value was used.  The estimated parameters of the PDF for three main dimensions of nuts and kernels indicated that G.E.V was best fit.  With increasing moisture content of the kernels from 4.20% to 29.64% (w.b.), true density and porosity were increased from 939.629 to 1,077.428 kg m-3 and 37.704% to 57.088%, respectively; and bulk density was decreased from 585.350 kg m-3 to 462.343 kg m-3.  When the moisture content of the nuts increased from 4.03% to 28.13% (w.b.), true density and porosity were increased from 1,025.124 kg m-3 to 1,149.700 kg m-3 and 38.562% to 56.55%, respectively, and bulk density was decreased from 629.81 kg m-3 to 499.532 kg m-3.  Values of coefficient of friction on all surfaces were increased with increasing moisture content.   Keywords: gravimetric properties, regression, log likelihood, normal distribution, Weibull distribution,generalized extreme value distribution, almond nu

Determination of some engineering properties of parsley (Petroselinum crispum L.) seeds and modeling

To design the planting, separating, threshing, sizing and packing machines for agricultural products, physical and mechanical properties of the products should be known. In this work some physical properties of parsley seeds were studied. Dimensional parameters including three principle dimensions, geometric mean diameter, equivalent diameter, arithmetic mean diameter, sphericity, volume, surface area, projected area, flakiness ratio and elongation ratio were measured using image processing technique. Also length, width and thickness distributions of parsley seeds were modeled using Gamma, Generalized Extreme Value and Weibull distributions. Gravimetrical properties including mass of single seed, thousand seed mass, bulk density, true density and porosity were measured. Effect of the container volume and fall height on bulk density and porosity were studied. Frictional properties of parsley seeds (static coefficient of friction on various surfaces and repose angle of based on bypouring, Hele-Shaw, empting and filling methods) were measured. Results showed that length, width and thickness of the seeds ranged (0.660 - 0.883mm), (0.524 - 0.752mm) and (0.490 - 0.744 mm), respectively. With increasing the container volume from 150 to 550 mL, bulk density of the seeds increased; but from 550 to 750 mL, it was decreased. True density and thousand seed mass of the seeds were 884.658 kg/m3 and 1.390 g. The values of friction coefficient on plywood, rubber, iron and galvanized surfaces were 27.35ᵒ, 24.17ᵒ, 19.31ᵒ and 14.77ᵒ, respectively. The values of filling and empting repose angles were 32.64ᵒ and 40.16ᵒ