RU2448784C1 - Channel for separation of cereals by air upflow for simultaneous separation of light and heavy inclusions - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to separator of grain and other loose materials and may be used in agriculture, flour-and-cereals industry, etc. Proposed separator operates using upflow formed by front, rear and lateral walls and comprises screen inclined from front wall to sear wall and intake and discharge openings. At least one rotary ledge is arranged on screen surface to adjust grain height h for not over tenfold mean grain thickness and provided with gummed layer on its outer surface. At least one holes is made in screen nearby ledge base with its diameter not exceeding eightfold grain thickness to remove heavy inclusions. Said ledge is oriented relative to channel sidewall at the angle other than right angle. Said ledge has base made from steel plate. Said ledge is attached to screen base and channel side walls by means of rod extending along ledge center. Gummed layer is arranged on ledge side counter grain motion.

EFFECT: higher efficiency of separation reduced damages of cereals.

6 cl, 3 dwg

Description

The invention relates to techniques for separating grain and other bulk materials by air flow, in particular to devices for cleaning and sorting grain, and may find application in the cleaning of grain and seeds in agriculture and grain processing products in the milling and cereal and animal feed industry and other industries .

The prior art pneumatic sorting channel for separating grain upward air flow formed by the front, rear and side walls. To enter the source material into the channel in the front wall there is a loading window, and to withdraw the waste material from the channel, the open lower part of the channel itself is used (Kulagin M.S. et al. Mechanization of post-harvest processing and storage of grain and seeds. M .: Kolos, 1979 , p. 35, RU 2193929, 12/10/2002; RU 2392066, 06/20/2010).

Studies of the operation of such a pneumatic sorting channel for separating grain by an upward air flow showed that the disadvantage is the inability to isolate heavy inclusions (stones, metal objects, etc.) simultaneously with the process of separating light impurities from grain.

To highlight these inclusions, it is necessary to establish the operation mode of the pneumatic sorting channel, in which all the processed material, together with light impurities, is carried out by the air flow outside the pneumatic sorting channel, and heavy inclusions exit through the lower part of the channel itself to output the processed grain. At the same time, the electric power consumption increases in comparison with the process of separating light impurities from grain by 15 ... 20%, since an increase in the air flow rate is required to remove all the waste material outside the pneumatically sorted channel.

In this regard, in order to clean the processed material from heavy impurities and light impurities, it is necessary to pass the processed material through the pneumatic sorting channel two times on known pneumatic sorting channels: the first time to isolate, for example, heavy inclusions, the second time to isolate light impurities.

The closest in technical essence to the claimed invention is a pneumatic sorting channel of grain selected as a prototype with an upward air flow formed by the front, rear and side walls, containing a grid installed with an inclination from the front wall to the back, and a window for receiving the source and output of the processed grain material . At least one steel protrusion is made on the surface of the mesh, which prevents the movement of heavy inclusions to the outlet of the purified material with a height of not more than fifteen times the average thickness of the grains of the processed material. At least one hole is made in the mesh at the base of the protrusion for outputting heavy inclusions of the material being processed. The protrusion is oriented relative to the side wall of the channel at an angle different from the straight one (RU 2377077, 12.27.2009).

This pneumatic sorting channel of the grain allows you to select heavy inclusions and light impurities for one pass of the processed material through the pneumatic sorting channel.

The use of the mesh in the channel improves the separation process, provides a slight increase in the efficiency of separation of grain material due to the fact that the mesh, having resistance to air flow, contributes to a certain alignment of its speed along the depth of the channel.

The disadvantage of this channel is the decrease in grain strength of various crops after they hit the protrusion at a speed higher than critical, and the effect of the protrusion material on the amount of injury.

Studies of the operation of such a channel showed that damage to the surface of the grain, its germ, the formation of internal and external cracks in the body of the grain occurred due to the impact of grain with a direct protrusion with the steel surface.

The process of grain destruction by impact, the speed of rebound of particles after their impact on a straight steel protrusion has a significant effect on the formation of cracks in them, in terms of the recovery coefficient.

The obtained data on the value of the critical speed of impact, at which structural changes in the grain begin, make it possible to more correctly select the protrusion material and the channel operation mode for grain separation by the ascending air flow.

The problem to which the proposed invention is directed, is to create a channel for separating grain by the ascending air flow, which would eliminate the above disadvantages.

The technical result achieved by the implementation of this invention is to reduce damage to the seeds (mechanical damage) with the effective separation of heavy and light impurities in one pass of the processed material through the channel (pneumatic sorting), that is, by isolating heavy inclusions simultaneously with the release of light impurities during grain processing materials of various cultures.

The specified technical result is achieved in the channel for grain separation by the upward air flow, is formed by the front, rear and side walls and contains a grid installed with an inclination from the front wall to the back, and a window for receiving the initial and output of the processed grain material, while on the surface of the grid at least one rotary protrusion made with the possibility of height adjustment h not more than ten times the average thickness of the grains of the processed material and having on the outer surface rubberized layer, which leads to a reduction in mechanical damage to seeds to an achievable minimum and prevents the movement of heavy inclusions to the output of the purified material.

At least one hole with a diameter of not less than eight times the average thickness of the grains of the processed material is made in the mesh at the base of the protrusion to output heavy inclusions of the processed material.

The protrusion is oriented relative to the side wall of the channel at an angle φ different from the straight line, has a base of steel plate and is attached to the base of the mesh and mounted to the side walls of the channel with a rod running along the center of the protrusion.

The rubberized layer is located on the side of the protrusion facing the oncoming movement of the processed grain material.

It was possible to reduce damage to the seeds by turning the protrusion at an angle φ and applying a rubberized layer instead of steel. The speed of the element of grain material before impact is directed at an angle of 90 ° to the common tangent drawn to the impacting bodies at the point of impact. As a result, the normal component of the velocity will be less than the velocity in a direct impact. Accordingly, the dynamic load associated with the shock pulse will decrease. This allows you to provide a "soft" mode of movement, primarily necessary for the processing of such easily injured crops: legumes and cereals.

When the protrusion is rotated through an angle φ, the test frequency increases from 0.12 s to 0.34 s, the endurance limits and the number of cycles until the grain breaks increase slightly. An increase in frequency leads to an increase in endurance limits. There are two factors that can contribute to this phenomenon. Durability is associated with the magnitude of plastic deformation during each cycle of loading change, and at high frequencies this time is short for deformation to occur, so that the resulting damage can be less. This effect is more important at high temperatures.

The concentration of stresses in the grain associated with defects, as a rule, leads to a decrease in the endurance limit. A fatigue crack is itself an incision causing a high stress concentration. In the area of the concentrator, the local stress in the grain rises.

In practice, grains passing through metal surfaces are often subjected to cyclic loading. In this case, due to contact friction, the surface layers of grains are destroyed.

The presence of contact friction during cyclic loading generally leads to a decrease in the cyclic strength of the grain.

The processed grain material in the channel is under the influence of the upward flow in a suspended and free state. Heavy inclusions and part of the grain at the optimal air flow regime for cleaning grain from light impurities move along the supporting grid to the exit of the processed material. The existing rotary protrusion (adjustable) with a rubberized layer on the supporting grid prevents the movement of heavy inclusions to the outlet of the cleaned material with a "soft" mode of movement, drawn at an angle of 90 ° to the common tangent, drawn to the impacting bodies, passing a moving grain mass at the point of impact. Heavy inclusions move along the pivot ledge and fall into the hole in the supporting grid, through which they are discharged outside the grain separation channel by an upward air flow.

The efficiency of the grain separation channel by the ascending air flow, the reliability of the process and the production of biologically valuable ones by minimizing mechanical damage with a different morphological and physiological maturity of the seeds when separating heavy inclusions and light impurities is ensured by the rational height h of the rotary protrusion and its use on the surface of the protrusion rubberized layer.

The invention is illustrated by drawings, where figure 1 shows a vertical section of a channel along the direction of movement of the processed material; figure 2 is a section aa of the channel of figure 1; in Fig.3 is a horizontal section of a channel perpendicular to the plane of Fig.1.

The channel for separating grain by an upward air flow is formed by the front 1, rear 2, and side 3 and 4 walls, contains a grid 5 for supporting the separating material, a window 6 for introducing the source material into the channel made in the front wall 1 above the grid 5, and a window 7 for the output of the processed material from the channel at the opposite rear wall 2. On the surface of the mesh 5 is a rotary protrusion 8 with a rubberized layer 9 on its outer surface, at the end of which there is an opening 10, namely, at the base of the protrusion 8, at least One hole diameter of at least eight times the average thickness of the processed material grains for transporting heavy inclusions treated material. The protrusion 8 with a rubberized layer 9 reduces mechanical damage to the seeds to an achievable minimum and prevents the movement of heavy inclusions to the output of the purified material.

The rotary protrusion 8 consists of a steel plate with a rubberized layer 9 on the side of the oncoming movement of the grain mass. The protrusion 8 is attached to the base of the supporting grid 5 and mounted to the side walls 3 and 4 of the channel using a rod 11 extending in the center of the rotary protrusion 8. The angle of rotation φ of the protrusion 8 is carried out by the handle 12. If two or more are located on the surface of the grid 5 pivoting projections 8, they are interconnected from the sides by means of rods (levers or the like) and height adjustment h (by angle φ) occurs synchronously / simultaneously and with the same angular velocity in one direction.

The workflow is as follows.

The initial grain material, consisting of grain and lighter than grain, impurities and heavy impurities, is fed through the window 6 into the channel, where it is exposed to upward air flow, pumped from the bottom of the channel or sucked from above by any generator of air flow (not shown). As a result of the impact of the ascending air flow, the grain material acquires the state of a fluidized bed in which it moves from the front wall 1 to the back 2, stratifying into fractions. Particles of a light fraction (impurity) float into the upper layers of the grain stream and are carried away by air from the channel, while the main grain remains in the lower layers of the processed material stream above the supporting grid 5, practically without touching it.

Heavy inclusions and parts of the grain mass remain on the surface of the mesh and move towards the exit of the processed material. When heavy inclusions meet with a rotary protrusion 8 with a rubberized layer 9, their movement to the exit of the processed material stops. They begin to move along the protrusion 8 and are discharged through the hole 10 in the grid 5 (supporting) outside the channel. The processed grain (main grain) overcomes the adjustable protrusion 8 by the "soft" mode of movement, at an angle of 90 ° to the common tangent, drawn to the impacting bodies at the point of impact, and leaves through window 7 to exit the cleaned grain, outside the channel, and heavy inclusions are delayed by the rotary projection 8.

The present invention allows the cleaning of grain material at the same time (for one pass through the channel for separating grain with an upward air flow) both from light impurities and from heavy impurities, reducing mechanical damage to seeds to an achievable minimum, and on the other hand, the morphological and physiological maturity of seeds during grain processing materials of various cultures.

Claims (6)

1. A channel for separating grain by an upward air flow, characterized in that it is formed by the front, rear and side walls and contains a grid installed with an inclination from the front wall to the back, and a window for receiving the source and output of the processed grain material, while on the surface of the mesh at least one pivoting protrusion is located, configured to adjust in height not more than ten times the average thickness of the grains of the processed material and having a rubberized layer on the outer surface. 2. The channel according to claim 1, characterized in that at least one hole with a diameter of not less than eight times the average thickness of the grains of the processed material is made in the grid at the base of the protrusion to output heavy inclusions of the processed material. 3. The channel according to claim 1, characterized in that the protrusion is oriented relative to the side wall of the channel at an angle different from the straight line. 4. The channel according to claim 3, characterized in that the protrusion has a base of steel plate. 5. The channel according to claim 4, characterized in that the protrusion is attached to the base of the mesh and mounted on the side walls of the channel using a rod extending along the center of the protrusion. 6. The channel according to claim 1, characterized in that the rubberized layer is located on the side of the protrusion facing the oncoming movement of the grain.

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