SIEVE WITH ROUND BARS

Technical Field The invention relates to devices for fractioning granular particles, mainly plant seeds. It can be used in agriculture, processing of the products of agriculture or food industry.

Background Art

Flat and cylindrical sieves are typically used to separate granular mixtures by particle size [1 , 2]. Such sieves have slots which are arranged in rows. When a sieve is functioning particles of granular mixture move on its surface. If the size of the particles is less than the size of the openings the particles pass through the openings. If the size of the particles is greater than the size of the openings the particles cannot pass through the openings. In the latter case the paricles either leave the sieve or remain in the openings until removed by a cleaning device. The process of separation comprises two stages, segregation and screening. Grain mixture is thinned by vibration, which allows the particles to relocate within the mixture.

The drawbacks of such sieves are low penetrability (a ratio of the area of openings to the area of the screen), which limits the productivity of the devices, and damage to seeds due to impact with edges of the openings, which are often burred.

These problems are partly solved by a known device, which comprises a frame, round grate bars, longitudinal slots between the grate bars, cross bars, the grate bars are welded to the frame at their endpoints and to cross bars at the intersection points, the cross bars are welded to the frame at their endpoints [3]. However, the cross bars, which are placed below the grate bars, have angles, which can damage seeds and diminish their crop productivity, or decrease conservation period for the seeds intended for processing.

Disclosure of Invention The object of the invention is to improve the sieve so that damage to seeds is diminished, particles are separated into fractions more effectively, mixture is better separated, separation process is more productive and cleaning of the sieve in facilitated. The object is achieved by Fadieiev's sieve, which comprises a frame with grate bars made of round rods, the grate bars are fixed to the frame at their endpoints and to cross bars at the intersection points, longitudinal slots between the grate bars, the grate bars are interconnected with cross bars, which are fixed to the frame at their endpoints, in accordance with the invention the cross bars have circular section and are fixed above the grate bars.

Technical result: Damage to seeds is diminished, seeds are separated more efficiently, the sieve can be cleaned better.

The technical result of the invention is achieved by making the cross bars circular in section, thus angles are absent and therefore the seeds are less damaged. Placing the cross bars above the grate bars facilitates thinning and stirring of the grain mixture which increases the efficiency of sifting.

Brief Description of Drawings

Figure 1. Fadieiev's sieve. Top view.

Figure 2. Fadieiev's sieve. Top view of a fragment of the sieve. Figure 3. Fadieiev's sieve. Cross-section of a fragment of the sieve.

Fadieiev's sieve contains a welded rectangular frame 1 and cross bars 2 made of round rods, which are welded to the frame. Below the cross bars 2 parallel round grate bars 3 are fixed to the frame 1 and the cross bars 2. The diameter of the grate bars 3 is 2 - 4 mm, the diameter of the cross bars 2 is 1 ,5 - 2,5 mm. The distance between the cross bars 2 is 30-50 mm. The width of the slot between the grate bars 3 is 0,5 - 15 mm.

Description of Embodiments

The device functions as follows. Fadieiev's sieve is designed for functioning in a separator. The sieve is forced to oscillate and granular particles, for instance, seeds are fed on the cross bars 3 and the grate bars 2. The width of the longitudinal slots is such that that granular particles of the desired size pass through the slots while the remaining granular particles move along the grate bars and eventually leave the sieve. The cross bars 2 intensify passing of granular particles by stirring them without slowing down their movement. The round grate bars 3 can bend when pressure is applied, e.g. when they are hit from below by elastic balls (not shown in the figures), then travelling waves are created on the sieve screen. This intensifies sliding of granular particles and reduces obstruction of transversal slots. Granular particles sometimes get stuck in the middle part of a slot between the grate bars 3 but it is enough to push the stuck particle to the upper part of the slot, then the particle will be moved towards the top of the sieve by circulation flows and will eventually slide away from the sieve. Intensive rotation of granular particles occurs in the upper part of the slot. This increases the speed of particle separation and allows to reduce the size of a sieve while increasing the productivity of separation.

The proposed construction of Fadieiev's sieve improves efficiency of the tools in which the sieve is used by reducing damage to seeds, improving the quality of separation and facilitating the cleanup of the sieve. References

1 . Kozhukhovsky I. E. Grain cleaning machines. Moscow, Mashinostroenie, 1974. - 198 p.

2. Reference book for a constructor of agricultural machines. Vol. 2 / A. V.

Krasnichenko, editor. - M: GNTIML, 196 . - 862 p.

3. Patent UA 37527 U, B07B 1/46 (2006.01); Fadieiev's sieve.; Appl. Ns U200809604, 22.07.2008; publ. 25.1 1.2008, bul. Ns 22/2008.