RU2663332C1 - Device for separation of grain - Google Patents

Abstract

FIELD: agriculture; machine building.SUBSTANCE: invention relates to agricultural machinery, namely to machines for post-harvest grain processing. Device for the separation of grain materials contains a grating mill connected to the frame by flexible suspensions, in which the upper and lower sieves are installed with inclination towards the movement of the processed material with ball cleaning mechanisms, and the unbalanced drive of oscillations of the sieve mill, including the unbalance with the vertical axis of rotation placed in the center of the masses of the sieve mill. Upper sieve is inclined towards the direction of material movement at an angle of 7–8°. Lower sieve is inclined towards the direction of material movement at an angle of 10–12°. Drive is designed to rotate the unbalance at a speed of 350–420 rpm.EFFECT: achieved technical result consists in improving the quality of grain cleaning by improving the separation of fine impurities and improving the efficiency of the gratings, thanks to their qualitative cleaning.3 cl, 4 dwg

Description

The invention relates to agricultural machinery, and in particular to machines for post-harvest grain processing.

A device for separating grain mixtures is known, containing a loading hopper, feeder and sieve mill with inclined sieves parallel to one another, sieves with an angle of inclination of 15 ° to the horizon (see AS SU No. 1645030, IPC: B07B 1/12 , publ. 30.04.91). The sieve mill is mounted on a frame on springs and is equipped with a vibrator located in the center of gravity, which informs the sieve mill of small-amplitude high-frequency oscillations perpendicular to the plane of the sieves. A disadvantage of the known design is the low efficiency of grain cleaning, due to the rapid descent of grain, small amplitude and uneven fluctuations in the area of the sieve.

Known sieve part of the grain cleaning machine containing mounted on suspensions of the upper single-tier and lower two-tier sieve mills, receiving vibrations from the eccentric shaft by means of connecting rods and performing rectilinear reciprocating vibrations (see patent RU No. 2229787, IPC: A01F 12/44, publ. 10.06 .2004).

The disadvantages of machines with eccentric drives include high vibrational loads transmitted to the machine frame through the eccentric shaft attached to it, and, as a result, low reliability, frequent breakdowns, and forced downtime. The oscillation frequency of the sieves in this case cannot be large.

Compared to an eccentric drive, an unbalanced drive consumes less energy to maintain vibrations and provides greater operational reliability due to balancing dynamic loads and reducing machine vibrations due to the absence of hard connections between the drive and the frame (the loads are transferred to the frame through the flexible suspensions of the sieve mill). Moreover, as a result of circular vibrations of the sieves created by an unbalanced drive, the trajectory of the movement of particles of the grain mixture is extended, which improves their passage through the holes of the sieves.

As the closest analogue to the claimed technical solution adopted air-sieve separator, the design of which is disclosed in the patent for invention RU No. 2372153, IPC: V07V 9/00, publ. November 10, 2009

The closest analogue is characterized by the following structural features similar to the essential features of the claimed device, namely, the presence of a sieve part, which includes a sieve mill connected to a frame (bed) by flexible pendants, in which the upper and lower sieves with ball mechanisms are mounted with an inclination in the direction of movement of the processed material cleaning up. The sieve mill performs circular oscillations under the influence of an unbalanced drive mechanism, including an unbalance fixed to the center of gravity of the sieve mill with a vertical axis of rotation.

On the upper sieve, grain is separated from large impurities, and on the lower sieve, small impurities are separated from grain.

Sieve installed in the mill body parallel to each other with a slope of 7 ° to the horizontal in the direction of movement of the material.

The disadvantages of the closest analogue include the low quality of grain cleaning from fine impurities at the lower separation level and, as a result, the low quality of cleaning obtained at the output.

In the mentioned solution, in order to increase the separator throughput and to complete the separation of impurities, the number of tiers is increased, several sieve packets are placed in each tier, joined together. However, this significantly complicates the design of the separator, making it cumbersome.

The invention is aimed at solving the quality problem of grain cleaning with the condition of maintaining the simplicity of the design of the device.

The technical result achieved by using the invention is to improve the quality of grain cleaning by improving the separation of fine impurities and increasing the efficiency of the sieves, by improving the quality of cleaning screening surfaces.

The aforementioned technical problem is solved in the proposed device for separating grain materials, comprising a sieve mill connected to the bed by flexible suspensions, in which the upper and lower sieves with ball cleaning mechanisms and an unbalanced oscillation drive of the sieve mill, including the center of mass of the sieve mill is an unbalance with a vertical axis of rotation, while according to the claimed invention, the upper sieve is inclined in the direction of movement of the material but at an angle 7-8 °, lower sieve - is inclined in the direction of movement of the material at an angle of 10-12 °, the actuator is rotatable with a speed unbalance 350-420 rev / min.

Unlike the closest analogue, the proposed design is characterized by different angles of installation of the sieves: the upper sieve is inclined towards the material at an angle of 7-8 °, and the lower one is placed at an angle of 10-12 °, as well as a high frequency of circular vibrations created by an unbalanced drive, which is not less than 350 rpm

The oscillation amplitude of the sieve mill is 18 ± 2 mm.

The use of self-cleaning sieves with ball cleaning in the separation device is preferable due to the simplicity of the design of the cleaning mechanism, lack of drive, ease of maintenance during operation, reliability and durability.

The ball cleaning mechanism of the sieve includes a pallet placed under the sieve with a mesh bottom and cells for placing balls formed by longitudinal and transverse partitions with inclined walls, which ensure that the balls are reflected upward in the direction of the screening surface.

The essence of the proposed technical solution and the influence of significant structural features on the achievement of the above technical results is illustrated by the following specific implementation example and drawings.

In FIG. 1 shows a General view of the proposed device for the separation of grain materials, isometry;

in FIG. 2 shows an example of using the device as part of a grain cleaning machine;

in FIG. 3 shows the ball cleaning mechanism of the sieve;

in FIG. 4 is a section A-A of FIG. 3.

The separation device (see Fig. 1, 2) comprises a sieve mill 3 connected to the bed 1 by flexible suspensions 2, in the casing of which there are upper 4 and lower 5 sieves with ball cleaning mechanisms, 4 pitched boards 6, gutters 7 and 8 for outputting the obtained fractions and an unbalanced drive of oscillations, including an unbalance 9 with a vertical axis of rotation fixed in the center of mass of the sieve mill 3, receiving rotation from an electric motor 10 mounted on the bed 1, through a belt drive 11. From above, the sieve mill can be closed protective nets 12.

The ball cleaning mechanism (see Fig. 3) includes a pallet 13 with a mesh bottom 14 located under the sieve 4, 5 (not shown in Fig. 3), divided by partitions 15 having inclined walls, into cells 16 for accommodating the cleaning balls 17. Upper the sieve 4 is inclined in the direction of movement of the material at an angle α ₁ = 7.5 °.

The lower sieve 5 is inclined in the direction of movement of the material at an angle α _{2 of} 10 ° in one sample and 11.5 ° in the other.

The angle of inclination of each sieve is fixed and is determined by the position of the guides of the sieve mill 3.

The frequency of circular oscillations of the sieve mill 3, corresponding to the frequency of rotation of the unbalance, is 375 rpm

The oscillation amplitude of the sieve mill is determined by the unbalance parameters and is 18 ± 2 mm.

The ability to work under conditions of high-speed loads is ensured by the high-quality performance of the attachment points of the sieves of the sieve mill and the placement of the unbalance strictly in the center of mass, which ensures uniform distribution of loads relative to the suspensions of the sieve mill, contributes to the durability of the device under high loads.

The device operates as follows.

Partially purified from light impurities, the grain mixture enters the sieve mill 3, where it successively passes through the two separation surfaces of the sieves 4 and 5. Particles of the grain material located on the sieve surface under the influence of circular vibrations of the sieve mill and gravity make a complex spiral-like movement, gradually moving forward down the sieve to the exit.

At the first stage of the circular motion, due to the action of friction and inertia forces, the sieve is ahead of the grain, as a result of which the latter separates from the sieve surface. With a small angle of inclination of the dividing surface (1-8 °), this gap is insignificant, and the grain, not having time to turn around, is again picked up by the sieve. There is a push of the material with a sieve, ensuring its advancement. However, the force of this push is small and, mainly, grain glides along the sieve 4 plane, during which, falling into the hole zone, the grain, together with small impurities, falls down, passes through the ball cassette of the cleaning mechanism and is fed to the lower sieve via sloping boards 6 5.

Large impurities descend along the inclined surface of the sieve 4 to the exit, where they fall into the collection chute 7 and are removed from the device.

The work of the upper sieve 4, providing the separation of large impurities, in the proposed device is practically no different from the work of the upper sieve in the closest analogue, installed at an angle of 7 °.

Fine impurities, due to their physical properties, are much more difficult to separate from the grain and at a small angle of inclination of the separation surface they will immediately go along the sieve along with the grain, therefore, the efficiency of cleaning grain from small impurities at an angle of 7 °, which takes place in the prototype, is low.

Increasing the angle α _{2 of the} inclination of the lower sieve 5 to 10-12 ° in the direction of movement of the material contributes to a better separation of grain from the surface of the sieve and an increase in the angle of attack from the side of the sieve on the grain torn off the surface. As a result of an increase in the angle of attack, the impact force of the sieve surface on the grain mass increases. The grain mass is thrown over the surface of the sieve 5 and at the same time it is well shaken, which contributes to its loosening and detachment of fine impurities from the grain, which then fall through the holes of the lower sieve 5 and the mesh bottom 14 of the pallet 13 and are collected in a special groove 8, from where they are then removed. Commodity grain is transported along the surface of the sieve 5 to the exit.

The periodic tossing of material on the lower sieve 5 as a result of the sieve impact is expressed in the wave-like movement of the grain mass over the surface of the sieve, which is clearly visible with the naked eye during operation of the device. As a result of the shaking effect, the intensity of separation of fine impurities from the grain increases, which improves the quality of its cleaning.

An increase in the angle of inclination of the lower sieve 5 more than 12 ° is undesirable, because in this case, the rate of descent of the grain mass increases, which leads to a deterioration of the separation process.

In addition to the angle of inclination, the high oscillation frequency of the sieve mill is important. The persistent effect of the wave-like movement of the grain mass with high quality separation at the output is observed at speeds greater than 350 rpm.

At unbalance rotation speeds of 9 less than 350 rpm, the grain mass does not have time to tear itself away from the sieve surface and slides down the sieve with a continuous mass. As a result, the mentioned effect of the “impact” of the sieve on the grain mass is not achieved.

Unbalance 9 rotation speeds above 420 rpm are undesirable, as Excessive increase in vibration loads can lead to structural failure.

The proposed design of the sieve separation device is built taking into account the differences in the physical properties of the separated fractions on the upper and lower sieve and ensures the creation of the most optimal conditions for the separation of each type of impurities and, as a result, high quality grain cleaning.

All the distinguishing features of the proposed technical solution work together, ensuring the achievement of the above technical result - improving the quality of grain cleaning.

At the same time, the proposed constructive solution is simple and can be used both in the production of new grain cleaning machines and for the modernization of operating ones.

The high-frequency mode of oscillations of the sieve mill, as well as an increase in the angle of inclination of the lower sieve 5, increase the intensity of movement of the balls 17 of the ball cleaning mechanism in the cells 16 of the pallet 13 and, as a result, increase the frequency of collisions of the balls 17 with the sieving surface of the sieve. As a result of more intense impacts, the quality of cleaning the screening cloth from particles stuck in it improves, which improves the efficiency of the sieve, improves the quality of grain cleaning, and maintains high productivity of the device.

The optimal height of the partitions 15 is preferably not more than half of the height of the cell 16, and the diameter of the balls 17 is 0.75-0.85 of the height of the cell, which ensures the required impact force of the balls and eliminates the presence of dead zones above the partitions, provides high-quality cleaning of the entire surface sieve.

Claims (3)

1. A device for separating grain materials, comprising a sieve mill connected to the bed by flexible suspensions, in which an upper and lower sieve with ball cleaning mechanisms and an unbalanced oscillation drive of the sieve mill are installed inclined in the direction of movement of the processed material, including a sieve mill oscillation drive, including a sieve mill located in the center of mass unbalance with a vertical axis of rotation, characterized in that the upper sieve is inclined in the direction of movement of the material at an angle of 7-8 °, the lower sieve is inclined in the direction of movement of the material under scrap 10-12 °, wherein the actuator is rotatable with a speed of the unbalance 350-420 rev / min. 2. The device according to p. 1, characterized in that the oscillation amplitude of the sieve mill is 18 ± 2 mm. 3. The device according to p. 1, characterized in that the ball cleaning mechanism includes a pallet with a mesh bottom and cells for placing balls formed by longitudinal and transverse walls with inclined walls located under the sieve.

Images