Selector 2

STUDIES AND RESEARCHES CONCERNING THE DESIGN AND ACHIEVEMENT OF SELECTORS FOR SEEDS USED IN THE SMALL FARMS ŢENU IOAN1, BERCOVICI CĂTĂLIN2 , 1 Technical University ”Gh. Asachi” Iaşi, Faculty of Mechanics Iaşi, B-dul Mangeron nr.63-65, Romania; 2SC IMA SA, str. Pavlov nr.14, Iaşi, Romania. Abstract: The cleaning and the sorting of seeds is a technological operation where by it follows the cleaning of impurities in such way that the seed material has to be brought to provided purities in the legal norms.For the achievement of one universal selector of middle capacity used on small farms it was carried out studies and researches concerning the finding of optimum constructive solutions. Consequently of these studies it has been designed and achieved an universal selector of the operating capacity of 500,1000 kg/h for seed material (wheat, barley, maize, lucerne, trefoil, sun flower)but for human consumption of operating capacity of 20003000kg/h. The tests have been achieved on laboratory conditions and they showed that the universal selector is a machinary which carries out a good cleaning of the seeds material or for consumption. Keywords: selector,seed,machinary,cereal. Generalities The grains, the vegetable seeds ,the grass seeds are subjected to the cleaning and the sorting after harvesting for bringing them at quality required on standard. The purity provided in standard is in function of the seed species and if these ones are destined for human consumption or for sowing. As generally, the seeds subjected to the cleaning are unhomogeneous and they contain different components such as: easy impurities (dust, chaff) impurities bigger then grains ( parts of straw, parts of wood, roops, paper, stones, parts of earth ) and impurities smaller than seeds (sand, weed seeds, small parts of land, breaked grains). This unhomogenity of seeds makes that the technological cleaning operation to be complex and for the its achievement it has to use the complicate installations. In these conditions the theoretical process of separating of seed mixing is expresed by the relation: η

t − ∫ Ps •dt = 1− e 0

(1)

where η-the extraction grade of the components formed from foreign bodies

PS=f(t) –the function of time which is determinated by separating process intensity and it depends on the operating regime of the separator and of mechano-physical properties of the mixings. If it has in account that the mechano-pneumatic separators for cleaning and sorting of the seeds are feeded by a constant flows, then the time function it is represented by a constant measure and Ps=k but the (1) equation becomes (2) Analysing this equation, it results that the theoretical separating process has an asymtotic evolution which means that the whole separating of the components from η=1-e-kt

a mixing by means of the one simple separator it is possible only for t= Thus, the separation it is achieved in the very short time, which makes that the fractioning operation of the mixing is carried out incompletly. Having in view the purity requirements which must have the cleaned seeds and on another hand the needs of the agricultural farmers for the providing with small capacity machinary used at separating and mixing, at SC IMA IASI it has been taken in study the designing and the achievement of one universal selector The construction and operating of the universal selector The universal selector is a mechano-pneumatic installation for the cleaning and the sorting after size and specific wheight of the cereal grains, technical plants and seed of grass. The machinary can assure the separating and the cleaning of the seeds destined for sowing when it is used in coupling with the trieur and for grains destined of the human consumption or industrialising. The universal selector is made up from the following subassemlies: the feeding modulus, pneumatic modulus, sorting modulus with sieves, trieur , the driving mechanism and the chassis. The feeding modulus (fig.1) is made up from a (1) bin of 100dm3 capacity and (2) a dosemeter with shutter and (3) driven rifled drum. The pneumatic modulus (fig1) assures the transport of seeds subjected of the cleaning and in the same time it extracts the easy impurities from mixing (dust, chaff, etc.) and from the grains with small specific weight. The pneumatic modulus is made up from the following elements: the feeding and dust extraction room which includes (4) a admission chanal, (6) dust removel room, (5) shutters for the regulating of air flow and (10) colecting chute for dust extracted seeds (7) the ventilator and two pneumatic spaces located on one side and on another side of the ventilator. On the inferior part, the spaces continuous by (11) a colecting chute provided with two oscillanting flaps hand operated, regarding to the periodic evacuation of the impurities which have not been aspirated by ventilator (8) the pneumatic room for the sedimentation of the grains with small specific weight which have been extracted from cleaned grains mass. This subassembly includes an aspiration chanal, the proper pneumatic room, (9) shutters for the regulating of the air flow and (12) the colecting chute for

evacuation of grains with small specific weight (breaked seeds). 13-The sorting modulus with sieves carries out the separating of the mixing components after size of seeds and it comprises: 24-superior sieve for the separating after length and width of the seeds (the oversizes product is made up from impurities with bigger dimensions than of the seeds from the base culture); 23-the inferior sieve achieves the separation after thickness (the sifting includes impurities by smaller dimensions then of the seeds from the base culture); 15-the cleaning mechanism by brushes, 21-the driving mechanism of the cassette with sieves and 14- the conducting mechanism of the brushes; 17-the trieur achieves the separating of the mixing after length and it extracts the breaked parts and weed seeds.

Fig 1. The constructive and functional scheme of the universal selector 1-feeding bin, 2-shutter, 3-dosemeter with trommel, 4-pneumatic tube for transport, 5,9-flaps for the regulating of air flow, 6-pneumatic room for dust extraction, 7-ventilator, 8-pneumatic room for sedimentation of the grain with small specific weight, 10-the colecting and evacuation chute for dust extracted seeds, 11the colecting and evacuation chute for easy impurities, 12-the colecting chute for sistavite grains, 13-the cassette of the cleaning sieves, 14-cranck mechanism for the driving of the cleaning brushes, 15-the sieve cleaning brushes, 16-electomotor, 17trieur, 18-chute for the evacuation of the cleaned grains,19 chute for the evacuation of the impurities extracted by trieur, 20-eccentric mechanism for the vibrating of the colecting chute of the trieur, 2-off-centre mechanism for the driving of the sieves cassette, 22-the selector frame, 23-inferior sieve, 24-superior sieve. As an assembly,the trieur is compounded principaly from:the trieur cylinder with cells; the oscillanting mechanism for driving by vibration of the collecting chute of seed weeds and impurities and the driving mechanism of cells cylinder. The sheet

of the trieur cylinder is achieved from two segments whom orifices are of different dimensions: D=5.25 and D=7. Due to rotating of the cylinder for first phase, the spherical impurities and seed weeds are extracted and for second parts, are extracted the impurieties which have the length smaller than of the base culture seeds, breaked and undeveloped grains. The universal selector operates in tandem by trieur only in case of seeds destinated for sowing. Fig.3 - The driving mechanism allows the motion of the compounded subassemblies of the selector by belt transmissions and cranck mechanism. The kinematic scheme is thought in such way that the selector is equipped by a single motor of 3KWx1500rpm and it allows the optaining of the different working regimes, depending on physico-mechanical properties of seeds for cleaning.

Fig 2 The kinematic scheme of universal selector Regulations and technical tests For determinating of the operating optimum regimes, it has been achieved tests using different types of crops, such as: -wheat (Ariesan variety)- 14.5% humidity, 3.6% foreign bodies, 1.8 breaked grains; -barley(Miraj variety)- 13.8% humidity, 4.2% foreign bodies, 1.2 breaked grains; -oat (Solidar-variety )- 13.5 humidity, 3.8% foreign bodies, 1.0% seeds; -sun-flower (Favorit variety)- 12.8% humidity, 4.8% foreign bodies, 2.1% breaked grains; -maize (Fundulea 270 variety)- 14.3% humidity, 1.2% foreign bodies, 1.6 breaked seeds; -soya-bean (Precoce 90 variety)- 12.8% humidity, 2.8% foreign bodies, 0.8% breaked grains; -rape (Triumf variety)- 13.6% humidity, 3.2%foreign bodies, 1.6% breaked seeds; -trefoil (Select variety)- 14.2%humidity, 3.6% foreign bodies, 1.9% defected and breaked grains; -lucerne (Gloria variety)- 13.7% humidity, 3.3%foreign bodies, 1.2% defected and breaked grains.

The tests has been achieved for each species of seed and in the different conditions of operating of the subassemblies, but after machining and interpretation of the results it was stated the optimum regulations for the operating of the selector (tab.1). For determination of the technical performances by the optimum regulations specified in tab.1, it was efected tests and it has been obtained the results from tab.2. The selector without trieur has been used for the cleaning of seeds for preservation. Analysing the results, it can conclude that the designed selector satisfies the requirements of the small agricultural farms both for the cleaning of seeds consumption and for sowing seeds. References 1.Ioancea L. – Condiţionarea şi valorificarea superioară a materiilor prime vegetale în scopuri alimentare, Ed. Ceres, Bucueşti, 1983; 2.Oancea I. – Agricultura generală, Ed. Ceres, Bucueşti, 1994; 3.Scupnic V. – Maşini agricole, Ed. Ceres, Bucueşti, 1994; 4.Ţenu I. – Tehnologii, maşini şi instalaţii pentru industrializarea produselor vegetale, Ed. Junimea, Iaşi, 1999.

Table 1. The optimum regulations for the universal selector Crops

Wheat Barley Oat Sunflower Maize Soyabean Rape Trefoil Lucerne

Position of the shutters for regulation ofthe air flow (feeding./clean ing)

Rotation of the ventilator (rot/min)

Rotation of the dosimeter for seeds destined: (rot/min) for for preservation sowing

Rotation (rot/min)

M/m M/m M/m M/m

1425 1100 1100 1100

85 85 85 85

65 65 65 85

30 30 30 30

M/M M/m

1840 1840

85 85

85 65

M/c M/c M/c

1100 1100 1100

85 85 85

65 65 65

Rotation of the trieur (rot/min)

The rotation of the eccentric shaft for seed destined (rot/min)

Type of sieves depending on destination of the seeds

preservation

sowing

for sowing

superior

inferior

superior

inferioară

33 32 25 -

for preserva tion 448 448 448 448

350 350 350 350

Φ5 Φ5 Φ4 Φ8

□2,5x25 Φ2,5 Φ2,5 Φ4

□4x25 □3,6x25 □3,6x25 □1,5x25

□2,5x25 □2x25 □2x25 □3,6x25

24 24

-

448 350

350 350

Φ10 Φ10

Φ5 Φ5

□10x25 □10x25

□4x25 Φ6

30 30 30

25 25

350 350 350

350 350 350

Φ3 □2x25 □2x25

Φ1,5 Φ1,3 Φ1,3

Φ3 □2x25 □1,6x25

□1,6x25 □1x15 □0,8x15

Notes: it was written down M,m,c the position of the shutters for the regulation of the air flow from the pneumatic and feeding rooms and properly from the sedimentation foreign bodies room; M-maximum,m-medium,c-closed

Table 2. Tehnical parameters of the selector for cleaning of seeds for preservation and sowing Crops

Initial parameters

Seeds for preservation-consumption

Sowing seeds

Wheat Barley Oat Sun-flower Maize Soya-bean Rape Trefoil Lucerne

Foreign bodies (%) 3,6 4,2 3,8 4,8 1,2 2,8 3,2 3,6 3,3

Foreign bodies (%) 1,9 2,0 1,3 1,7 0,8 1,1 1,2 1,4 1,3

Foreign bodies (%) 0,72 0,32 0,36 0,69 0,23 0,16 0,26 0,32 0,36

Breaked seeds (%) 1,8 1,2 1,0 2,1 1,6 0,8 1,6 1,9 1,2

Breaked (%) 0,6 0,7 0,2 0,9 0,6 0,3 0,7 0,8 0,7

seeds

Productivity (kg/h) 1220 1080 960 1010 1320 1360 980 920 880

Breaked (%) 0,06 0,01 0,01 0,08 0,023 0,032 0,07 0,06 0,55

seeds

Productivity(kg/h) 568 546 488 496 680 720 430 425 435