SU1143345A1 - Apparatus for cleaning grain - Google Patents

Abstract

1. DEVICE FOR CLEANING GRAIN, containing an oscillating sieve mill with at least two lightly-arranged lattices, the lower one of which is displaced relative to the upper direction of the processed material, as well as a loading hopper, a pneumatic channel with a suction nozzle for sampling light impurities and trays for withdrawal of similar material the fraction of the upper sieve and the passage fraction of the lower sieve, characterized in that, in order to increase the productivity and efficiency of cleaning, it is provided with a guide wall, the upper sieve at an adjustable angle in its longitudinal axis, and a tray for removal of the tailing sieve fraction is installed on the side of the latter in front of the guide wall at the top of the acute angle formed in the plan by the side of the upper sieve and wall, and has a threshold located in the beginning of the tray. 2. The device according to claim 1, characterized in that the working surface of the end portion of the lower sieve is made concave, and the vsa (The lance fitting is installed above this portion. 3. The arrangement according to claim I, characterized in that the upper portion is provided with a receiving portion, having loosening lty. OOD j: sd

Description

The invention relates to a technique for separating granular materials and can be used in the construction of air-grading machines for the preliminary purification of grain. A known grain cleaning machine, for pre-cleaning a heap of grains and other crops, contains a drainage chamber, an air cleaning system, a sieve mill and a device for shipping waste and clean grain 1. The disadvantage of this machine is its low productivity due to the fact that blowing in the cereal mixture at the inlet limits the flow, and cleaning the drying is done on flat sieves with a grain flow close to the monolayer. At the same time, the machine is characterized by a low cleaning efficiency from light impurities with different physicomechanical properties, since the air flows in the channels mutually influence one another and do not allow their independent adjustment. Closest to the invention is a device for cleaning grain, containing an oscillating sieve mill with at least two stern-mounted sieves, the lower one of which is mixed relative to the upper one in the direction of movement along the sieves of the material being processed, as well as the hopper, pneumatic channel with a suction lance impurities and trays for removal of the waste fraction of the upper sieve and the passage fraction of the lower sieve 2. A disadvantage of the known device is the low cleaning efficiency. In addition, the device does not provide high performance, since the supply of grain mixture is limited due to its purging at the entrance and cleaning a thin layer of the mixture on the sieve. Due to the fact that the sieves in the device are made flat, it is impossible to effectively clean the grain mixture from impurities with different physicomechanical properties that require different kinematic conditions for their separation. The purpose of the invention is to increase the productivity and efficiency of cleaning. This goal is achieved in that the device for cleaning the grain is provided with a guide wall mounted on the end section of the upper sieve at an adjustable angle to its longitudinal axis, and a tray for discharging the tail fraction of the upper sieve is installed on the side of the latter in front of the directed wall at the top of the acute angle formed in terms of the lateral side of the upper sieve and wall, and has a threshold located at the beginning of the tray. In addition, the working surface of the end portion of the bottom sieve is made concave, and the suction nozzle is installed above this portion. In this case, the upper sieve is provided with a receiving portion having loosening pins. FIG. 1 schematically shows the proposed device for cleaning grain, side view; in fig. 2 is a view A of FIG. one; in fig. 3 shows a section BB in FIG. 2. The device contains a hopper 1, an oscillating sieve mill with a mounted longitudinal with a relative longitudinal displacement of the upper 2 and lower 3 sieves associated with the fan 4 pneumatic channel 5 with the suction nozzle 6, the tray 7 of the exhaust sieve fraction 2 (for shipment large waste), installed at the end of the gathering part of the sieve 2, tray 8 for removal of the passage fraction of sieve 3 (small and heavy waste) installed under the lower sieve 3, and tray 9 for removal of the waste fraction of this sieve (pure grain). The sieve mill is suspended on suspensions of adjustable length (not shown) and installed with the possibility of horizontal circular oscillations. The receiving section of the upper plate 2 is located under the bunker 1 and is made in the form of a trough, on the solid bottom of which the loosening pins 10 are reinforced. Tray 7 has an inclined threshold 11 2-2-4 cm high at its beginning and is installed on the side of the sieve 2 in front of the guide wall 12 located at the end of the sieve 2 at an adjustable angle to its longitudinal axis. Means for adjusting this angle may be different (not shown). The wall 12 forms in the plan with the lateral side 13 of the sieve 2 an acute angle, at the top of which a tray 7 is installed. The lower sieve 3 has a rectilinear reception and a curved (concave) vent part. The change in concavity is performed by one of the known methods. The nozzle 6 of the pneumatic channel 5 is made in the form of a slit air intake with deflectable flaps 14 for controlling the air flow and is installed above the tail section of the lower sieve 3. The device operates as follows. The grain pile from the hopper 1 enters the receiving section of the sieve 2, where it is leveled, loosened and pre-stratified by the action of vibrations and using pins 10, the fine fraction enters the bottom layer and the large one floats upwards. The small fraction, moving along the sieve 2, sifts and falls onto sieve 3. The wall 12, stopping the longitudinal movement of the passage fraction and changing the direction of movement of the converging fraction, carries out their separation. The threshold 11 and the wall 12 provide an accumulation of a dedicated passage fraction, along which the converging fraction moves over the threshold and enters the tray 7. By rotating the wall 12 in the plane of the sieve 2, the angle of inclination to the longitudinal axis of the sieve is adjusted. The grain mixture delivered to the lower sieve 3 is a mechanical mixture of many particles (chaff, weed seeds, full-sized, broken and shredded grain, mineral impurities, etc.) with different physical and mechanical properties. Depending on these properties, each particle has its own optimum kinematic mode for vertical displacement in the layer and for sieving. The cleaning efficiency of small and heavy particles is determined by the intensity of sieving through the holes of the slit. Due to the fact that the mixture is stratified under the influence of circular sieve oscillations 3 in the horizontal plane and the mixture layer on the sieve has a different thickness, the kinematic mode is created along the entire sieve length, which is favorable for separating light and sifting small and heavy impurities with various physical and mechanical impurities. properties. Thus, on the lower sieve 3, the grain mixture is divided into light impurities, clean grains and small and heavy impurities. Light impurities are sucked from the surface of the clean grain, moving together at the bottom of the 9, and fine and heavy impurities are passed by the passage into the tray 8 for shipment. The presence of wall 12 and threshold 11 on the upper sieve 2 allows to increase the cleaning efficiency, since the wall, by ceasing the longitudinal movement of the grain mixture along the sieve and changing the direction of movement of the straw heap (descent), ensures their separation, and together with the threshold increases the layer of grain mixture and intensive screening, which increases the performance of the device. Installing the wall 12 with the ability to adjust its angle to the longitudinal axis of the sieve provides effective cleaning of the grain heap and high performance of the device with changes in the direction of sieve oscillations and physical properties of the processed heap of grain (humidity, debris, etc.). The installation of the suction inlet above the gathering part of the lower sieve 3 also allows to increase the cleaning efficiency, as it ensures the timely removal of light impurities that pop up on the surface of the processed grain and prevents them from falling into the tray 9, and, in addition, allows you to remove light impurities from the processed grain without blowing it, i.e. to increase the performance of the device. Making the final section (cage) of the bottom sieve 3 with the possibility of changing the concavity allows smoothly increasing the thickness of the grain mixture layer and creating optimum zones along the length of the slit for separating particles of impurities with different physicomechanical properties, which contributes to an increase in the efficiency of grain cleaning. An increase in the thickness of the grain mixture layer on sieve 3 contributes to an increase in the productivity of the device, since the intensity of sieving increases with increasing thickness, which increases the loading of the device. The presence of pins 10 allows to pre-intensively exfoliate the grain mixture and ensure contact with the sieve of only the passage fraction, which increases the intensity of screening on the upper sieve 2. Since the smallest particles of the passage fraction pass into the lower layer during the separation, they are first sieved before fall on the lower sieve 3, which ensures their more intensive screening on this sieve. The proposed device allows to increase the overall grain cleaning efficiency from 40-60% to 80%, and for individual weeds, such as small seeds (bristle, camel, etc.), the cleaning efficiency is 99-99.8% . According to the tests of the prototype of the device, an increase in the grade of the grain heap from 10 to 36.2% at a constant performance does not impair the cleaning efficiency. It is 79–80%, while on airborne sieve machines it’s 40–50% with significantly lower productivity. The performance of the proposed device in comparison with the known (OPV20, ZVS,, ZSN-50, ZS-50) with a lower installation capacity is 5-6 times higher and does not depend on the humidity and weights of the heap of grain entering the treatment. The specific energy consumption of grain cleaning on the proposed device is 5–8 times less in comparison with the known ones (OPV-20, ZVS-20, etc.) due to the fact that the grain is cleaned without blowing it. A fan of considerably lower power is used to select light volumes. The application of the invention allows to speed up the process of pre-cleaning of cereal crops and thereby ensure their safety, reduce the cost of their production and storage.

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Claims (3)

1. DEVICE FOR CLEANING GRAIN, containing an oscillating sieve mill with at least two tier-mounted grids, the lower of which is offset from the upper c; the direction of movement of the processed material, as well as a loading hopper, a pneumatic channel with a suction pipe for selecting light impurities and trays for removing the descending fraction of the upper sieve and the passage fraction of the lower sieve, characterized in that, with the aim of increasing productivity and cleaning efficiency, it is equipped with a guide wall, installed on the final section of the upper sieve at an adjustable angle in its longitudinal axis, and the tray for removal of the descending fraction of the upper sieve is installed on the side of the latter before guide wall at the apex of the acute angle formed by a plane lateral side of the upper sieve and the wall, and has a threshold arranged at the beginning of the tray. 2. The device according to π. 1, characterized in that the working surface of the final section of the lower sieve is made concave, and the suction pipe is installed above this section. 3. The device according to π. 1, characterized in that the upper sieve is equipped with a receiving section having loosening pins.