RU2391150C1 - Pneumatic system for installation of loose mixture air separation in fluid medium - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: invention relates to pneumatic systems of devices for air separation of loose materials, for instance seeds of cereals, vegetables and grasses, and may be used to treat and sort grain in breeding stations, elevators, in farms, plants for production of seeds and cereals, and also in flour-grinding, mixed fodder, chemical and other industries. Pneumatic system in plant for air separation of loose mixture in fluid medium comprises high pressure fan, jet generator connected to it, with flat nozzles arranged in it under each other and at the acute angle to vertical line, and height of their cross sections, as well as pitch and angle of installation, increase top-down, and also chamber of separation formed by side walls for elimination of air suction into internozzle space and generation failure, and separating device located below chamber of separation and including collectors for direct fractions turned towards one side, and collectors for intermediate fractions turned towards the opposite side, and via air duct connected to hopper for accumulation of initial material. Additional common hopper with inclined walls is installed under collectors of intermediate fractions. Pneumatic system has additional branch formed by high-pressure fan and additional air duct, end of which is directed towards the common hopper. At the end of additional air duct there is a movable narrowing nozzle installed, and Laval nozzle is installed coaxially to it, under output hole of the common hopper, and Laval nozzle is connected to air duct, in which a detachable device is installed for additional milling of loose material of intermediate fractions arranged in the form of set of pins installed transversely to air duct, end of which adjoins semi-cyclone.

EFFECT: improved efficiency of repeated separation and capacity, and also reduction of separation time and expansion of functional capabilities.

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Description

The invention relates to a pneumatic device for the air separation of bulk materials, eg seeds of cereal, vegetable and grass crops, and can be used for cleaning and sorting of grain at breeding stations, elevators, in ^- farms, factories for the production of seeds and cereals, as well as flour, feed, chemical and other industries.

A separator is known, the pneumatic system of which includes a fan, from which the inclined air channel directly leaves, into which the bulk material is fed by the feeder towards the air flow so that the feed direction or the feed rate vector of the source material forms an acute angle with the average air velocity vector in the channel. In this case, light impurities with high wind factors are immediately captured by the air flow and move along the upper trajectories to the inertial dust separator. Heavier components of the initial bulk mixture having small wind factors, overcoming the resistance of the air flow, move for some time in the channel towards the air flow due to the stock of kinetic energy. Further, they are also captured by the air flow and along shorter lower trajectories fall into the respective receivers of the separation products located at a closer distance from the place of supply of the initial bulk mixture. This design of the device allows to increase the feed rate of bulk material and, accordingly, increase the speed of the air flow, which increases the separation performance with reduced length of the air channel [see US Pat. Of Ukraine No. 9928U in class B07B 4/02, published on October 17, 2005].

A significant drawback of this separator pneumatic system is that the air channel is made short and is adjacent directly to the fan. It is well known that at the output of any fan a turbulent air flow is formed, which does not have time to transform (align) into a laminar flow in a short channel. Therefore, the separation of the granular mixture occurs in a turbulent air flow, and this circumstance cannot, in principle, provide the necessary quality of separation of the granular mixture into separate fractions, and, with increasing air velocity, due to increased turbulence, the separation quality will accordingly decrease . Thus, the known pneumatic system cannot provide a sufficient quality of separation of the granular mixture because the air channel is made short and is located in the immediate vicinity of the fan.

This disadvantage is eliminated in the separator, the pneumatic system of which consists of a fan creating a horizontal air flow along the working channel, which then goes into a pipeline having a significantly smaller cross-section than the working channel. The pipeline is connected to a cyclone, after which, on the other side of the working channel, a fan is located. That is, the fan is located at the maximum distance from the working channel. The fan, through a pipeline and a cyclone, draws in air from the environment and delivers it to the working channel evenly over its entire cross section, that is, with a laminar flow. Under the influence of the air flow, heavy particles of the material to be separated fall into the receiver closest to the pipeline, and light particles fall into the farthest receiver located directly near the working channel (near the air intake zone). Between the extreme fraction receivers are intermediate receivers for the fractions, which by their weight are between the heaviest and lightest fractions. Dust particles move into the cyclone, where they are discharged into the atmosphere through an air lock [see US Pat. Of Ukraine No. 22962U in class B07B 4/00, published on April 25, 2007].

The disadvantage of this pneumatic system is that when it is used, a rather low separation efficiency of bulk mixtures due to the continuity of the air flow is achieved, which entails a low quality of separation with an increase in the feed of the initial bulk mixture into the channel due to the interception of particles of different weights, or low productivity at high quality of separation at piece feed of the separated material. To increase the separation efficiency, it is necessary to significantly increase the size of the channel, which is impossible in modern grain cleaning machines.

Separation of a continuous air stream into a cascade of flows with different rates of air flow is proposed in the separator pneumatic system, including a fan, a tilted air channel, in which an additional device is installed with a mechanism for controlling the air speed along the channel height. This device is made in the form of a set of rotary plates mounted on axes passing through the axial lines of the device sidewalls, and the axes of the rotary plates are fixed parallel to the lower (upper) walls of the device. The position of the rotary plates is fixed by the clamping bar. When separating the granular mixture, the source material is fed into an inclined air channel, that is, into the zone of action of the air flow created by the fan, and with the help of rotary plates the air stream is converted into a channel uneven in height, more intense in the upper part of the channel and more moderate in its lower parts. When turning the plates, the devices achieve that the velocity change plot is described by a convex parabola in the direction of air supply and asymmetric to the upper part of the channel. Under the influence of such an air flow, the heaviest components of the granular mixture having low wind coefficients fall into the corresponding receiver, and the components (grains) with large wind factors are separated and fall into other receivers intended for collection, and make up crushed and small grains of the main culture, or seeds (impurities) of other crops (e.g. weeds). Biological impurities (husk) and dust enter the dust separator. Depending on the clogging of the source material, the difference in the numerical characteristics of the division curves of the coefficient of windiness of the seeds of the main culture and impurities, the height and length of the channel, the average air velocity and the feed of the raw material into the channel, the degree of curvature of the plot is changed by changing the cascade of air velocities along the height of the channel. At the same time, when cleaning seed mixtures with a large difference in the numerical characteristics of the curves for dividing the windiness coefficients of the seeds of the main culture and impurities and a high clogging of the initial mixture, the degree of curvature of the plot of the change in air flow rates in the cascade is increased. This provides a high speed of transportation of the components of the mixture in the upper part of the channel, reducing their concentration in the loading zone. In addition, light impurities separated from the source material by a more intense air flow are completely removed from the separation zone (the main part of the channel is intensively unloaded), which contributes not only to an increase in the separator performance, but also to better conditions for the separation of components with closer air coefficients in average and the lower parts (in height) of the channel. To separate mixtures with approximately equal wind coefficients, the degree of curvature of the plot of the velocity change in the cascade is reduced, which naturally leads to a decrease in the separator performance, but ensures high quality separation of the granular mixture into fractions. They increase productivity when separating more homogeneous mixtures by increasing the average air flow rate in the channel and the feed rate of the source material into the air channel, or, with the corresponding curvature of the plot, by increasing the height or length of the channel. Changing the degree of curvature of the diagram of air flow velocities in the channel is carried out by changing the angles of inclination of the rotary plates of the regulation mechanism [see US Pat. Of Ukraine No. 70667 in class B07B 4/02, published on October 15, 2004].

The aforementioned design of the separator pneumatic system does not ensure uniformity of air jets at the exit from the slots of the turning plates of the device. This leads to a rupture of the cascade of jets, as a result of which particles of the separated material can mix with each other. All this affects the quality of the separated material for the worse.

This disadvantage is eliminated in the pneumatic system of a device for separating granular mixture in a fluid medium, including a fan connected to a jet generator with flat nozzles made with different cross-sectional heights of their channels, installed with different spacing between them and located at different sharp angles to the vertical, this value of the indicated heights of the cross section of the channel, pitch and acute angle increase in the direction from top to bottom. The separation of the granular mixture consists in the gravitational supply of particles of the source material, aerodynamic monotonically increasing action on them at an acute angle to the vertical by a cascade of flat jets and the output of the finished fractions in the collectors, which are located in the bottom of the separation chamber [see US Pat. Of Ukraine No. 45881 for class B07B 4/02, published on April 15, 2002].

The disadvantage of this pneumatic system is that the alternating and free operating mode of the cascade of jets inevitably leads to the periodic, unstable in time and space appearance of pressure and rarefaction zones in it with the appearance of forward and reverse flows. In the zone of reverse flows of the air flow, particles (especially light ones) are drawn in the direction opposite to the direction of movement of the main stream, which leads to partial mixing of the already separated material. The instability in time of this phenomenon ultimately leads to the breaking (breaking) of the cascade of jets in any random place, which further enhances the reverse flow in this zone and, as a result, intensifies mixing. In addition, the opening contributes to the breakdown of generation (termination of the oscillatory process), which significantly reduces the quality of separation, bringing it closer to the quality of separation usually with a fan.

The closest in essence and the achieved effect, taken as a prototype, is the pneumatic system of the installation for air separation of a granular mixture in a fluid medium, including a high-pressure fan, a jet generator connected to it, with flat planes located in it under each other and at an acute angle to the vertical nozzles whose cross-sectional height, pitch and installation angle increase from top to bottom, as well as a separation chamber formed by the side walls to prevent air leakage into the inter-nozzle space and stall generating and separating device located below the separation chamber and includes collections Straightening fractions deployed in one direction, and collectors for intermediate fractions, deployed in different (opposite) side and connected through a duct with a hopper for storing starting material. The separation of the granular mixture with the help of this device pneumatic system consists in the gravitational supply of particles of the source material from the hopper, the aerodynamic monotonically growing action on them at an acute angle to the vertical by a cascade of flat jets and the withdrawal of fractions in different collectors and the return of intermediate fractions into the hopper for re-separation [see US Pat. Ukraine №60254 in class B07B 4/02, A01F 12/44, published July 15, 2005 in Bull. No. 7].

The main disadvantage of the known pneumatic system — the limited functionality of the system — can be seen when using the device for separating seeds of certain crops due to the fact that it cannot affect the physical condition of the seeds of intermediate fractions, since it is not related to their collections. This disadvantage is explained as follows. The grains of some crops can stick together, for example, pumpkin seeds, due to the presence of a surface film on them, or ostyaks remain on them due to under-grinding, for example, on barley grains, husks and the like. Such a source material during separation, of course, is in the collections of intermediate fractions, from where it enters the hopper for re-separation using the duct. Since the air duct does not in any way affect such seeds (does not change their physical state), upon repeated separation, such grain will again fall into the collections of intermediate fractions, and this process will be repeated endlessly, since the physical state of such seeds does not change. Consequently, unchanged conditions for the separation of intermediate fractions of seeds leads to a gradual accumulation of the noted fractions in the hopper, and because of this, naturally, the performance of the plant for separating seeds will decrease.

The basis of the invention is the task of expanding the functionality of the pneumatic system of the installation for the separation of granular mixture while increasing its productivity and separation efficiency by changing the physical state of the intermediate fractions of the separated material by aerodynamic grinding and separation of the adhered material into separate parts.

The solution to this problem is achieved by the fact that the known pneumatic system of the installation for air separation of a granular mixture in a fluid containing a high-pressure fan, a jet generator connected to it, with flat nozzles located in it under each other and at an acute angle to the vertical, the height of the cross sections of which , the step and the installation angle increase from top to bottom, as well as the separation chamber formed by the side walls to prevent air leakage into the inter-nozzle space and disruption of generation, and the separation device thy, located at the bottom of the separation chamber and including collectors for direct fractions, deployed in one direction, and collectors for intermediate fractions, deployed in the opposite direction, and through an air duct connected to the hopper to accumulate the source material, according to the proposal, an additional general set under the collectors of intermediate fractions a hopper with inclined walls, and the pneumatic system has an additional branch formed by a high-pressure fan and an additional duct, the end of which is directed to the second hopper, and, at the end of the additional duct, a movable tapering nozzle is installed, and also coaxially with it, under the outlet of the common hopper, there is a Laval nozzle connected to the duct, in which there is a removable device for grinding bulk material of intermediate fractions, made in the form of a set pins mounted transverse to the duct, the end of which is adjacent to the half-cyclone.

An additional branch of the pneumatic system provides the function of transporting intermediate fractions to the duct, performing an additional function: influencing the physical state of these fractions, namely, dividing the adhered material into separate particles (grains) and grinding those grains that need it due to the presence of a removable device in it for a hammer. The presence of a half-cyclone prevents the return of dust and threshing waste to the hopper, which generally improves the productivity and efficiency of separation of the granular mixture in the air stream.

A further essence of the proposed technical solution is illustrated in conjunction with illustrative material, which shows the following: figure 1 - pneumatic system for air separation of a granular mixture in a fluid medium, side view; figure 2 is a longitudinal section of a section of the duct with a device for threshing intermediate fractions, the process of separating sticky seeds into lumps; figure 3 is the same process of grinding seeds with ostyaks. The arrows indicate the movement of air currents. Black spots are a conditional image of particles of separated material.

The pneumatic system of the installation for air separation of a granular mixture in a fluid medium comprises a high-pressure fan 1, a jet generator 2 connected to it, with flat nozzles 3 located one under the other and at an acute angle to the vertical, the cross-sectional height of which, step and installation angle increase from top to bottom, as well as the separation chamber 4, formed by the side walls to prevent air leakage into the inter-nozzle space and disruption of generation. Under the separation chamber 4 there is a separating device, including collectors for direct fractions 5, deployed in one direction, and collectors for intermediate fractions 6, deployed in the other (opposite) side. All collectors for intermediate fractions 6 are sent to a single common hopper 7. The conveying device of the intermediate fractions of the separated material is made in the form of an additional branch of the plant pneumatic system formed by a high-pressure fan 8 and additional duct 9, the end of which is directed to the common hopper 7. At the end of the additional duct 9 a movable tapering nozzle 10 is installed. Under the outlet of the common hopper 7, a Laval nozzle 11 is located, which together with the nozzle 10 forms an ejector assembly of pressing the intermediate fractions of the material into the duct 12. In the duct 12 there is a removable device 13 for breaking the bulk material of the intermediate fractions, made in the form of a set of pins 14 mounted across the duct 12. At the end of the duct 12, a half cyclone 16 is located above the hopper 15, in which aerodynamic separation takes place bulk material of intermediate fractions from waste of the hammering process. The intermediate fractions of the bulk material are returned to the hopper 15 for re-separation, and the waste of the hammering process is removed outside the installation through the duct 17.

A further essence of the invention is explained in conjunction with the principle of operation of the proposed pneumatic system of the installation for air separation of a granular mixture in a fluid medium.

First, the particles of separated material from the hopper 15 are gravitationally fed into the separation chamber 4. The particles of separated material that are in free fall are acted at an acute angle to the vertical by a cascade of plane air jets in the developed turbulence mode, which is formed due to the curvature of the jets during their expansion into nozzles 3. During the passage by the particles of the material of the cascade of jets, the material is divided into separate fractions and, further, the direct fractions are output to the collectors 5. Simultaneously enno this intermediate fractions are selected in the accumulator 6 to return them to re-separation. The process of returning the intermediate fractions for re-separation is as follows. Since a common hopper 7 is located under all the collectors 6, the material of intermediate fractions is inside it and rolls down along the inclined walls of the hopper 7. Under the action of the air flow in the additional air duct 9 and in the presence of an ejector suction unit of the material formed by the Laval nozzle 11 and the tapering nozzle 10 , the material of intermediate fractions is sucked into the duct 12, through which it is transported to the device of the hammer 13. In the device of the hammer 13, particles (grains and fragments of adhering grains) of the material collide with fixed pins 14. Due to the kinetic energy of the moving particles, sticky clods of grains break up and crush (remainder stumps) grains that need it. Further, the separated and crushed grains, as well as dust and waste of the hammer are moved through the air duct 12 to the half cyclone 16, in which the bulk material is returned to the hopper 15 for re-separation and the waste of the hammer process is removed outside the installation. The ejector suction power of the material can be adjusted by moving the tapering nozzle 10 using the regulator 18.

Thus, the proposed pneumatic system can improve the efficiency and productivity of the separation of seed mixtures into fractions due to the influence on the physical state of the material of the intermediate fractions using the device for the hammer 13. If there is no need for such a device for the hammer 13, it is removed from the pneumatic system and a fragment is installed in its place duct 12.

A significant difference between the claimed object and the previously known is that the pneumatic system of the separation unit is equipped with an additional branch with a device for ejector suction of material and a device for hammering. From the point of view of energy consumption, no change has occurred: pneumatic transportation of intermediate fractions of bulk material needs certain energy expenditures. But pneumatic transportation allows you to disperse the particles of the material and in this way provide them with a supply of kinetic energy, due to which, in the device for the hammer, the pins affect the physical state of the particles of the material, in particular, the breakdown of the individual components into clumped lumps, and the grinding of grains that need it. These differences, in aggregate, allow you to expand the functionality of the pneumatic system, which automatically increases the efficiency and productivity of the process of separating the granular mixture into separate fractions.

The technical advantages of the proposed technical solution, in comparison with the prototype, include the following:

- expanding the functionality of the pneumatic system due to the introduction of an additional branch;

- the possibility of breaking up lumps of material and hammering due to the inclusion of an additional pneumatic branch and a device for hammering;

- improving the efficiency of re-separation due to changes in the physical state of the intermediate fractions of the material;

- improving the performance of the device for separation due to the fact that particles of intermediate fractions are no longer returned to the respective collectors;

- reduction of separation time due to a single return of intermediate fractions for re-separation;

- universality due to the fact that the device for the hammer is made removable.

The social effect of the implementation of the proposed technical solution, in comparison with the use of the prototype, is obtained by increasing the yield of the finished product, as well as due to a better separation process.

The economic effect of the implementation of the proposed technical solution, in comparison with the use of the prototype, is obtained by increasing the productivity of the process of separation of the granular mixture.

The proposed technical solution has been tested in practice, therefore, acceptable for industrial use, such pneumatic systems with marked essential features have not been found in known sources of information, and therefore it is considered such that it can receive legal protection.

After describing the proposed pneumatic system of the installation for separating a granular mixture in a fluid medium, it should be obvious to those skilled in the art that all of the above is only illustrative and not restrictive as presented by this example. Numerous possible modifications of the elements of the pneumatic system, in particular, the device for the hammer, its size, can vary depending on the state and type of the original loose separated material, and, of course, are within the scope of one of the usual and natural approaches in this field of knowledge and are considered as such, what are within the scope of the proposed technical solution.

The quintessence of the proposed technical solution is that the pneumatic system is equipped with an additional branch for transportation and a device for influencing the physical parameters of the intermediate fractions during transportation due to the shock load on the material particles when they collide with the hammer device, and this circumstance made it possible to acquire the listed pneumatic system higher and other advantages. Changing the proposed principle of returning intermediate fractions and the principle of influencing their physical state on others naturally limits the range of advantages listed above and cannot be considered new useful technical solutions in this field of knowledge, since another pneumatic system like the one described does not require any creative approach from designers and engineers and can not be considered the results of their creative activities or new intellectual property subject to protection Yelnia documents.

Claims (1)

Pneumatic system for air separation of a granular mixture in a fluid containing a high-pressure fan, a jet generator connected to it, with flat nozzles located underneath each other and at an acute angle to the vertical, the cross-sectional height of which, step and installation angle increase from top to bottom as well as a separation chamber formed by the side walls to prevent air leakage into the inter-nozzle space and disruption of generation, and a separating device located at the bottom of the separation chamber and including collection nicknames for direct fractions, turned in one direction, and collectors for intermediate fractions, turned in the opposite direction, and through the duct connected to the hopper for accumulating the source material, characterized in that an additional common hopper with inclined walls is installed under the collectors of intermediate fractions, and the pneumatic system has an additional branch formed by a high-pressure fan and an additional duct, the end of which is directed to a common hopper, and at the end of the additional duct A movable tapering nozzle has been renewed, and also coaxially with it, under the outlet of the common hopper, there is a Laval nozzle connected to the air duct, in which a removable device for grinding the bulk material of intermediate fractions is located, made in the form of a set of pins mounted transverse to the air duct, the end of which is adjacent to the half cyclone.

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