RU2161070C1 - Grain washing installation, admixture hydraulic separator and method of separation of admixtures from grain - Google Patents

Abstract

FIELD: food industry; baking. SUBSTANCE: grain washing installation has washing bath with inclined bottom, auger installed over bottom, and treated material feeder in form of distributing grid. First hydraulic separator with device for delivering separating liquid is arranged over bath under distributing grid. Second hydraulic separator is installed under drain of first hydraulic separator is directed opposite to drain of first hydraulic separator. In first hydraulic separator, grain passes through distributing grid into zone of turbulized downward current where material is stirred by streams of separating liquid. Larger particles settle on sieve, smaller particles drop into bottom space. EFFECT: improved cleaning of grain material. 12 cl, 4 dwg

Description

 The invention relates primarily to the food industry, in particular to washing grain and cleaning it from impurities in preparation for baking bakery products from dispersed grain.

 The preparation of grain before dispersing it and obtaining a test mass for baking bakery products is subject to increased requirements, since the ingress of solid impurities, such as small stones, into the dispersant leads to breakage of knives, and the ingress of light impurities into the test mass, such as residues of rough shells of grain , reduces the baking quality of products.

 A known installation for washing cereals containing a washing bath with an inclined bottom in the form of a part of a cylindrical surface with a discharge window in the upper part of the bottom and drain windows in the side walls, a screw installed above the bottom between the discharge window and the opposite end wall of the bath, means for supplying a processed material, means for supplying a separating liquid (water), moreover, a V-shaped partition is mounted in the lid of the bathtub, separating the part of the bathtub, where the means for supplying the processed material and overt window from part to the discharge window. The means for supplying the separation fluid is located in the lower part of the bath on the end wall (A.S. N 1500361, B 02 B 1/04, 1987).

 Thanks to the baffle, in this installation, light impurities that have emerged are well separated, while heavy impurities can be carried away by the screw along with the grain.

 Closest to the proposed technical solution is the installation for washing grain 221.M3-02.00.00.000 (passport 221.M3-02.00.00.000. Substation, extracts from which are attached).

 This installation is taken as a prototype.

 The installation comprises a washing bath with an inclined bottom in the form of a part of a cylindrical surface with a discharge window in the upper part of the bottom and drain windows in the side walls, a screw installed above the bottom between the discharge window and the opposite end wall of the bath, an auger drive, means for feeding the processed material, installed above the bathtub under the means for supplying the material to be processed, the first hydroseparator with means for supplying the separation fluid, equipped with a body with a drain, and placed under its drain, swarm hydroseparator equipped with a body with a drain.

 The installation of the unit with hydroseparators allows to improve the separation of heavy impurities and to intensify the washing of grain due to the additional processing in the hydroseparators.

 However, due to the fact that the discharge of the hydraulic separators is directed to one side and oriented towards the discharge window, with a high concentration of grain in the pulp, it is possible to entrain the flow of grain of heavy impurities. In addition, to prevent light impurities from entering the screw, intensive drainage is required, which entails an increased flow rate of the release liquid.

 A dressing device is known, including a housing, in which a sieve and a concave trough adjacent to it are formed with the formation of a bottom cavity and a means for supplying the processed material and separation liquid in the form of pulp. Moreover, the bent edge of the gutter forms an overflow threshold, and the rising part of the bottom of the body forms an ascending channel for the flow of separation liquid (A.S. N 1606193, B 03 B 5/70, 1989).

 In this device, the sieve is used for sieving material by size. The separation by density occurs mainly in the bottom cavity in the upward flow in the channel between the trench and the bottom.

 There is a known method of gravitational enrichment of bulk material, in which the feed zone of the processed material is intersected by a jet stream of separation liquid, using the direct action of thin, non-flooded jets, and the force of action on each piece depends on its size, and the acceleration in the direction of the jet depends on its mass.

 A device for implementing the method comprises a means for supplying the material to be processed and an inkjet apparatus for supplying a separation fluid oriented at an angle to the material flow (A.S. N 1005357, B 03 B 5/00, 1980).

 Due to the fact that this method uses the direct action of liquid jets, it is suitable for processing a discharged stream of material with the size of pieces larger than the cross section of a single jet. This method is not effective when processing a dense stream of fine-grained material, for example wheat grains.

 A known method of separating suspensions, which consists in feeding the material to be processed together with the separating liquid in the form of pulp into the recirculation zone, over which an upward flow of the separating liquid overflows over the threshold.

 A device for implementing the method comprises a chamber with a loading funnel, under which a vibratory flow former is placed, and the chamber is equipped with an overflow threshold (A.S. N 484003, B 03 B 5/62, 1971).

 Effective implementation of the method requires a sufficiently extended zone of the upward flow, which entails large dimensions in the vertical direction of the device for its implementation.

 In addition, the device has a complex mechanism for generating a recirculation zone, is intended mainly for cyclic operation and is poorly integrated into the production line.

 Known depositor machine comprising a housing, a sieve installed in the housing with the formation of a bottom cavity and an overflow threshold, means for supplying the processed material and separation fluid to the sieve in the form of a pulp, made in the form of a tray mounted at an acute angle to the sieve. A pulsator is installed in the bottom of the casing, providing recirculation of the release fluid through the sieve. In the oversize part of the casing, fairing floats are installed to damp turbulent pulsations of the pulp stream.

 The operation of this device implements a method for separating impurities from a granular material, including feeding the material to be treated and the separation fluid to the perforated base, organizing the circulation of the separating liquid through the perforated base and draining the extracted part of the material through the overflow threshold, and the circulation through the entire base is uniform due to pulsations static pressure under the base (A.S. N 1440541, B 03 B 5/12, 1987).

 This device and the method implemented in its work are taken as a prototype.

 The device and the method implemented in its work are intended for the separation of heavy mineral suspensions with a high content of heavy fraction. The liquid is circulated through the entire perforated base evenly and serves mainly to separate the bed of the processed material while moving relatively slowly towards the overflow threshold, but even in this case, a special tool is required to damp turbulent pulsations at the drain level to prevent entrainment of heavy particles through overflow threshold. In addition, preliminary pulp preparation is required.

 The use of these methods and devices for cleaning, for example, grain, when it is necessary to isolate a very small amount of heavy impurities from a large mass of light fractions while ensuring high quality, is ineffective due to the relatively low processing intensity and large dimensions of the device associated with large buoyancy of grain.

 One technical problem solved by the invention is to improve the quality of cleaning grain material from heavy impurities, such as small pebbles, by reducing the likelihood of their entrainment by the flow of pulp of their hydroseparators.

 The essence of the proposed technical solution lies in the fact that in the installation for washing grain material containing a washing bath with an inclined bottom in the form of a part of a cylindrical surface with a discharge window in the upper part of the bottom and with at least one drain window, an auger installed above the bottom between the discharge the window and the opposite end wall of the bath, auger drive, means for supplying the processed material, installed above the bath under the means for feeding the processed material, the first hydraulic separator with medium The means for supplying a separation fluid, equipped with a housing with a drain, and a second hydroseparator placed under its drain, equipped with a housing with a drain, is new in that, unlike the prototype, the second hydroseparator is installed in such a way that its drainage is directed opposite to the drain of the first hydroseparator.

 With this placement of the hydroseparator, the pulp flow of the processed material is inhibited and unfolded, which contributes to its separation and the release of heavy impurities in the second hydroseparator not caught in the first hydroseparator.

 The effect is achieved with any placement of the hydroseparators relative to the washing bath, for example, when orienting the discharge of the second hydroseparator to the side walls of the bath.

 When the body of the second hydraulic separator is adjacent to the side walls of the bathtub and placed so that its bottom is below the level of the overflow of the bath’s drain window, and the drain is directed to its end wall, an additional effect is achieved - the hydraulic separator’s body simultaneously serves as a partition separating the part of the bath with the drain window where easily floating impurities get from the part of the bath with the discharge window, preventing these impurities from entering the finished wash product.

 With this arrangement of hydroseparators, it is most advisable to drain through the end wall, because in this case, the simplest design of the washing bath and the liquid drainage system with pop-up light impurities is obtained, however, drainage can be done through the window and in the side wall, for example, to lengthen the trajectory of individual grains, but fluid drainage is complicated and measures must be taken to prevent stagnation at the end wall, for example, by installing a divider, which complicates the design.

 Another technical task is to increase the efficiency of separation of a small amount of heavy impurities from grain material.

 This problem is solved in the proposed method for separating impurities from the grain material, including the supply of the processed material and the separation fluid to the perforated base, the organization of the circulation of the separation fluid through the perforated base and the discharge of the allocated part of the material through the overflow threshold, in which, unlike the known method, the circulation of the separation liquids are carried out by creating a downward turbulized flow in the feed zone and an upward flow in the discharge zone with the formation between them a recirculation zone.

 As a result of this flow organization, zones are formed with different effects on the material to be separated. In the first zone, the material undergoes strong mixing by a turbulent downward flow, and the heaviest particles are released here. When the separation fluid passes through the perforated base, turbulent pulsations are suppressed, causing fluctuations in the static pressure in the fluid under the base, which are transmitted to neighboring zones, causing small-scale fluid circulation through the perforated base, and its intensity decreases towards the overflow threshold.

 In the second zone, where a recirculation flow is formed, particles are transferred from the boundary of the upward flow to the border of the downward flow and are lowered, forming a bed on the perforated base, where, with attraction, they are moved back to the border of the upward flow zone. Here, the material is separated in the field of centrifugal forces of the macrovortex of the recirculation zone and as a result of saltation on a perforated base, which is enhanced by small-scale circulation. Moreover, as a result of recirculation, the material undergoes separation many times. Here the main mass of impurities stands out.

 In addition, this zone is a damper that dampens turbulent downward flow pulsations, preventing their influence on the upward flow.

 In the third zone, material arriving at the base from the recirculation zone undergoes gravitational separation in the upward flow.

 A downward turbulent fluid flow can be organized by feeding it together with the processed material in the form of pulp, turbulizing it by any suitable known method.

 Upstream can be provided from a separate source.

 The recirculation zone between the descending and ascending flows is formed automatically when they are relatively displaced along the base.

 Obviously, to ensure sufficiently intense circulation in the recirculation zone, the downward and upward flows must have a sufficient relative speed, which is associated with an increase in the overflow level and an increased flow rate of the separation liquid. In addition, with a high concentration of pulp, the problem arises of locking the perforation of the base with the settled grains of the processed material.

 The most simple and effective flow is organized when the separation fluid is supplied by the jet stream, in the form of separate flooded jets, crossing the material supply zone at an acute angle to the base. The jets, ejecting the pulp, intensively turbulize it, energize the recirculation zone and promote the movement of material in bed.

 The material can be supplied both in the form of pulp and in dry form. When fed dry, intensive mixing with the jets ensures quick wetting of the grains without the formation of their aggregates, and there is no need for preliminary preparation of the pulp.

 In order to regulate the separation process depending on the properties of the processed material, the angle of inclination of the jet stream and its dynamic pressure are changed.

 Creating an upward flow by turning the downward flow under a perforated base allows the process to be carried out at a reduced flow rate of the separation liquid and simplifies the device for its implementation.

 The method is implemented in a hydroseparator comprising a housing, a sieve installed in the housing with the formation of a bottom cavity and an overflow threshold, means for supplying the material to be processed and means for supplying a separation liquid, different from that known in that the means for supplying a separation liquid is made in the form of an inkjet apparatus oriented towards the overflow threshold at an acute angle to the sieve, and the means for supplying the processed material is placed with the possibility of crossing the flow of the processed material in a jet stream of separation fluid.

 When processing material with constant hydrodynamic properties, the hydroseparator is operable at a constant angle of inclination of the jets.

 To configure the hydroseparator for processing materials with various hydrodynamic properties, its jet apparatus can be equipped with a mechanism for changing the angle of inclination of the jets and means for regulating the pressure.

 To ensure a sufficient upward velocity of the separation fluid at the overflow threshold without using additional means, the bottom cavity formed by the sieve and the bottom of the body is made tapering towards the overflow threshold, i.e. in the form of a confuser, in which the fluid flow is accelerated.

 The simplest in design is the implementation of the jet apparatus in the form of a manifold nozzle with nozzles mounted in the housing parallel to the drain threshold, which contributes to the uniform distribution of the jet across the width of the hydraulic separator.

The description of the invention is illustrated by drawings, where
in FIG. 1 shows a general view of the washing bath, side view;
in FIG. 2 - same, plan view;
in FIG. 3 - node inkjet apparatus;
in FIG. 4 is a cross-sectional view of a hydroseparator with a flow distribution diagram.

 The installation comprises a washing frame 2 mounted on a support frame 1 with an inclined semi-cylindrical bottom 3, side walls 4 and an end wall 5. An unloading eye 6 is made in the upper part of the bottom 3. A drainage pipe 7 is installed in the lower part of the end wall 5, in its upper part drain window 8. Above the bottom 3 of the bath 2, between the end wall 5 and the discharge window 6, a screw 9 with a drive 10 is installed. Above the bath, at its end wall 5, a first separator 11 is installed, the casing of which 12 is made with a drain 13 facing side of the discharge window 6. Under the drain 13 of the first hydroseparator 11, a second hydroseparator 14 is installed, the body of which 15 is adjacent to the side walls 4 of the washing bath 2 and fixed thereto, the bottom of the body 15 being located below the drain level of the drain window 8. The body 15 is made with the drain 16 facing to the side end wall 5 of the washing bath 2.

 The separation fluid supply system (not shown in the drawing) through the control valve 17 and the flexible pipe 18 is connected to the L-shaped manifold pipe 19, which is installed in the housing 12 of the first hydraulic separator 11 at the wall opposite the drain 13 and parallel to it, passing through holes in the side the walls of the housing 12, and is fixed through seals with the help of a nut 20 and a lock nut 21 on one wall and a dummy nut 22 on the other. The collector pipe 19 is equipped with a number of nozzles 23. A distribution grid is installed above the collector pipe 19, which is the last link of the material supply means.

 A sieve 25 is installed in the housing 12 of the first hydroseparator 11 with the formation of an overflow threshold 26 and a bottom cavity 27 at the drain 13, the bottom of the housing 12 being profiled so that the bottom cavity 27 has a maximum depth under the distribution grid 24 and tapers towards the overflow threshold 26. B the sieve of the second hydroseparator 14 is also equipped with a sieve 28 with the formation of a bottom cavity 29 and an overflow threshold 30, the sieve 28 being installed with a slope towards the discharge 16, and the bottom of the body is profiled so that the depth of the bottom strips and 29 increases toward the overflow weir 30. Sieves 25 and 28 are formed with holes smaller than the grain size of the material being processed, the sieve 28 has smaller openings.

 The installation is equipped with a settling tank 31 located under the drainage window 8 of the washing bath 2 and connected to a drainage system (not shown).

 The installation is also equipped with a washing system for the screw (not shown in the drawing).

 The upper part of the washing bath 2 is closed by a lid 32.

 Installation works as follows.

 The separation liquid is fed through the valve 17, the flexible pipe 18 and the manifold pipe 19. Subsequently, the hydraulic separators 11 and 14 and the washing bath 2 are filled to the drain level.

 Turn on the drive 10 of the screw 9. The grain, which has undergone peeling and pneumatic separation, through the distribution grid 24 enters the first hydroseparator 11, where it is wetted by the jet stream of the separation liquid and intensively mixed. In this case, the grain is preliminarily cleared of dirt and the remains of rough shells and the heaviest impurities are released from it. As you move to the drain 13, the pulp undergoes an increasingly finer separation.

 Passing the drain 13, the pulp stream unfolds, falls onto the sieve 28 of the second hydroseparator 14, where the flow is inhibited and turns around again. This contributes to stratification of the pulp. When it enters the inclined sieve 28, the pulp dissipates, and the separation fluid passing through the sieve 28 into the bottom cavity 29 carries away smaller, heavier impurities, washing them down along the inclined bottom into the deep part of the bottom cavity 29 adjacent to the overflow threshold 30. Here, the flow it slows down, particles settle, and the liquid rises through a sieve 28 through a sieve 28 to a drain 16. Grain enters this stream through a sieve 28, rises by it, undergoing final cleaning from heavy impurities in the upward flow, and through the overflow threshold 30 pours into the sink 2.

 The pulp stream, moving from the drain 16 of the second hydroseparator 14, is divided: the grain sinks to the bottom, and the hydrodynamic light impurities with the liquid flow through the drain window 8 are removed into the filter sump 31. In this case, the liquid coming from the auger washing system into the washing bath 2, creates at its end wall 5 a weak upward flow, contributing to the removal of suspended particles of fine dusty particles.

 The grain falling to the bottom of the bath 2 is picked up by the screw 9 and fed to the discharge window 6, finally being washed with liquid from the auger washing system.

 Bath 2 is periodically washed. At the same time, dirty water is discharged through the drain pipe 7. Due to the low content of heavy impurities, manual periodic cleaning is sufficient to remove them from the hydraulic separators.

 The first hydroseparator 11, where a method of separating impurities from a grain material is implemented, works as follows.

 Dry grain material through the distribution grid 24, evenly distributed over it, enters the zone I (Fig. 4) of the turbulized downward flow. In this zone, through the manifold pipe 19 and the nozzle 23, the separation liquid is flooded by jets at an acute angle to the sieve 25, which serves as a perforated base. The jets of liquid eject the pulp from the recirculation zone II, and the dry material is wetted and mixed by the jets. Here, in a highly turbulized flow, the heaviest impurities are separated out, the larger particles settle on the sieve 25, and the smaller ones fall into the bottom cavity 27. The total flow, as a result of interaction with the incoming dry material and the pulp of the recirculation zone, unfolds, passes through sieve 25, leaving grain on it and, braking when interacting with the bottom of the housing 12, is cut into two streams. The first, weaker, unfolding, rises along the wall opposite the drain 13 and, as a result of the ejective action of the jet, unfolds along the sieve 25, providing attraction of grains of material that fell on the sieve in this zone, towards the recirculation zone.

 The second flow, more powerful, turns towards the overflow threshold 26. The fluid flow, moving in a narrowing channel formed by the bottom of the housing 12 and the sieve 25, the cells of which are blocked by the material grains formed in the recirculation zone of the bed, the hydraulic resistance of which is high and the flow rate through them is practically equal to zero, accelerates, providing a fairly intense upward flow in zone III along the overflow threshold 26.

 The turbulent pulsations of the downward flow in zone I during passage through the sieve 25 and braking during spreading are suppressed, causing static pressure pulsations that are transmitted to zone II, where they cause small-scale circulation flows through the sieve 25, loosening the bed and enhancing the saltation of the material grains, thereby contributing to the release heavy impurities. Moreover, the intensity of the pulsations as a result of the interaction of the flow with the perforated base (sieve 25) due to the fact that the grain of the material in bed, acting as a kind of valves that change the hydraulic resistance of the mesh sieve 25, decreases in the flow, so that in zone III it becomes almost laminar.

 In zone III, the flow of separation fluid, turning around and passing through the sieve 25, forms a stream ascending along the overflow threshold 26, in which the grains of material moving out of bed in recirculation zone II float and undergo gravity separation. When the upward flow in zone III spreads, part of the grains is carried away through drain 13, and part is returned to the boundary of zone I by the return movement of the macro-vortex of the recirculation zone, goes down and again falls into bed on sieve 25. Material that repeatedly enters the recirculation zone is divided into a centrifugal force field macrovortex of the recirculation zone (mainly at the zone boundaries) and when attracted in bed on a sieve under the influence of small-scale fluid circulation through the sieve. In this zone, the bulk of heavy impurities is released.

 To adjust the process of separating the grain mass, the valve 17 controls the pressure of the jets, and to adjust the angle of the jets, weaken the mounting of the manifold pipe 19 with nuts 20, 21, and 22 and, having set the desired angle, re-fix it.

Claims (12)

 1. Installation for washing grain material, comprising a washing bath with an inclined bottom in the form of a part of a cylindrical surface with a discharge window in the upper part of the bottom and at least one drain window, an auger installed above the bottom between the discharge window and the opposite end wall baths, auger drive, means for supplying the processed material installed above the bathtub, under the means for supplying the processed material, the first hydroseparator with means for supplying the separation fluid, equipped with a housing Liiv, and placed under its second drain hydroseparator equipped with a drain housing, characterized in that the second hydroseparator mounted so that its drain is directed opposite to the first drain hydroseparator.  2. Installation according to claim 1, characterized in that the housing of the second hydroseparator is made adjacent to the side walls of the bath, its bottom is placed below the level of the overflow of the drain window, and the discharge is directed to the end wall.  3. Installation according to claims 1 and 2, characterized in that the drain window is made in the end wall of the bath.  4. The method of separating impurities from the grain material, including the supply of the processed material and the separation fluid to the perforated base, the organization of the circulation of the separation fluid through the perforated base and the discharge of the allocated part of the material through the overflow threshold, characterized in that the circulation of the separation fluid is carried out by creating a downward turbulent flow in the feed zone and the upward flow in the discharge zone with the formation of a recirculation zone between them.  5. The method according to p. 4, characterized in that at least part of the separation liquid is supplied by a jet stream, crossing the material supply zone at an acute angle to the base.  6. The method according to claim 4, characterized in that the processed material is fed in a dry form.  7. The method according to claim 5, characterized in that the angle of inclination of the jet stream and its pressure are regulated.  8. The method according to claim 4, characterized in that the upward flow of the separation fluid is created by turning the downward flow under the base.  9. A hydraulic separator for separating impurities from the grain material, comprising a housing, a sieve installed in the housing with the formation of a bottom cavity and an overflow threshold, means for supplying the processed material and means for supplying a separation liquid, characterized in that the means for supplying a separation liquid is made in the form a jet apparatus oriented towards the overflow threshold at an acute angle to the sieve, and the means for supplying the processed material is placed with the possibility of crossing the flow the material to be sprayed with a stream of separation fluid.  10. The hydroseparator according to claim 9, characterized in that the jet apparatus is equipped with a mechanism for changing the angle of inclination of the jets and means for regulating their pressure.  11. The hydraulic separator according to claim 9 and 10, characterized in that the inkjet apparatus is made in the form of a manifold with nozzles installed in the housing parallel to the drain threshold.  12. The hydraulic separator according to claim 9, characterized in that the bottom of the body forms a cavity tapering towards the overflow threshold with a sieve.

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