RU2448783C1 - Air separator with rotary barriers for upflow separation of cereals and other loose materials - 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. Rotary barriers are arranged across sidewalls above support screen with variable clearance. Protective screen is arranged above said support screen with its total area Ω exceeding support screen total area S to satisfy inequality 2Ω>S. Screen air upflow capacity is related to screen mesh size to satisfy inequality f·h>j·k, where f is protective screen mesh width; h is screen mesh height; j is support screen mesh width; k is support screen mesh height. Air separator comprises filter secured to blower outlet and provided with collector with self-controlled impurity discharge valve attached thereto and to be opened by gravity of accumulated mass.

EFFECT: higher quality and efficiency of separation.

2 cl, 7 dwg

Description

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

A known seed cleaner with a channel for separating grain by an 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 for the output of the heavy fraction from the channel, the open lower part of the channel itself is used. For the accumulation of light impurities - particles (dust) suspended in air, there is a dust collector (Seed Cleaner SVU-5, MS Kulagin and others. Mechanization of post-harvest processing and storage of grain and seeds. M: Kolos, 1979, p. 35) .

When operating over time, there is a deterioration in the quality of air cleaning due to a decrease in the air flow rate due to excessive clogging of the dust bag with light impurities. In this regard, to maintain a stable airflow, the operator often needs to monitor the state of the dust bag.

Studies of the operation of such a channel showed that the air velocity in the channel near the front wall where the grain material is introduced is not high enough for the effective removal of light particles due to the high resistance of the relatively dense grain flow, while at the opposite wall, where the grain stream has already been distributed in height into an easily blown stream, the air speed is too high, which leads to the removal of an increased amount of high-grade grain along with a light component (A.Ya. Malis and A.R. Demidov. Cleaning machines grain by air flow. M: Mashgiz, 1962, p.30-56, Fig.17, 29-30).

In this regard, the performance of the seed cleaning machine is increased mainly due to the channel width, increase in dimensions and frequent cleaning of the dust collector, which determines the large dimensions of the machines, the complexity of uniform loading along the channel width, the decrease in the efficiency of separation of grain material in comparison with machines with lower productivity and excessive clogging of the dust collector light impurities.

In the production seed machines used to date, the channel width, as a rule, is many times greater than its depth.

Filter elements, dust collectors with large dimensions and frequent clogging with light impurities are used, which leads to intensive wear and a decrease in the reliability of individual parts of the filter elements.

The closest analogue in technical essence to the claimed invention is the selected grain cleaning pneumatic sorting machine with a channel for separating grain with an upward air flow (Cleaning pneumatic sorting machine PSM-5, V.F. Fedorenko and E.L. Revyakin. Grain cleaning - condition and prospects. M. : Federal State Institution "Rosinformagroteh", 2006, p.204).

The machine consists of a pneumatic sorting channel formed by the front, rear and side walls, a supporting grid installed with an inclination from the front wall to the back, a hopper for receiving, a device for adjusting the material supply from the window for receiving the initial and output of the processed grain material - an unloading device for the purified material, sedimentary chamber of feed grain, a mechanism for adjusting the air flow, fan and fan frame.

To ensure the safe operation of the machine, a filter system is installed at the fan outlet - filter elements (burlap) that accumulate light impurities.

The filtering system consists of a filter housing, a filter element located in an upright position and in a suspended state, fixed to the base of the filter housing by a clamp.

The required degree of uniformity of the distribution of the air flow velocity along the depth of the channel and the corresponding increased efficiency of separation of grain material in the channel are provided by stabilizing the density of the processed grain flow along the depth of the channel using barriers.

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 required sanitary and hygienic conditions for the operator (dustiness) are provided by filter elements that perform accumulation and prevent the emission of light impurities into the atmosphere.

The disadvantage of such a grain cleaning machine is the low reliability of the filter elements (burlap), the complexity of maintenance and the need for regular monitoring of the clogging of the filter element.

The operational complexity of shifts maintenance was 0.10, people The specific total operational complexity of maintenance is 0.03 people / h.

Studies of the operation of such a channel showed that the supporting grid in the channel improves the separation process, however, when operating on grain flows, it is clogged with foreign impurities. The efficiency of separation of grain material is reduced by up to 70% due to the fact that the useful area is locked in the grid, which contributes to the destabilization of the distribution of the air flow velocity along the channel depth.

During the operational study of the grain cleaning machine, it was found that the process of accumulation of filter elements is accompanied by a destructive distribution of the speeds of the components of the grain mixture in the ascending air flow. As a result, with 100% oat isolation, barley losses can be up to 87.63%, and the separation efficiency, as they accumulate in burlap, can be no more than 23.22%. The maximum separation efficiency with this pattern is not more than 31.68%, with barley losses of 31% and the completeness of oat isolation of 90.4%.

The obtained data on the distribution of the speeds of the soaring of the components of the grain mixture in the upward air flow, at which violations of the technological processes in the grain cleaning machine are observed during the processing of grain crops, makes it possible to more correctly select the design of the filtration system and the means of protecting the supporting grid from clogging with external impurities when absorbed by air.

The problem to which the proposed invention is directed is to create a pneumatic separator that would take into account the degradation of the distribution of the speeds of the components of the grain mixture caused by the violation of the throughput of the supporting mesh and excessive accumulation of foreign impurities in the filter element, and would eliminate the above disadvantages.

The technical result achieved by the implementation of this invention is:

- in maintaining the efficiency of the process of separation of grain material during long-term operation of the air separator on grain flows;

- in protecting the supporting grid from external impurities by installing a rectangular shape under it, an additional protective grid with a cell size in the lumen of the grid 2x2 mm, with a total area of twice the supporting grid;

- elimination of excessive accumulation of impurities in the filter element by installing in the filter element an accumulator with a self-regulating valve to discharge impurities.

The specified technical result is achieved in a pneumatic separator containing rotary barriers, a channel for separating grain with an upward air flow formed by the front, rear and side walls, and containing a supporting grid and windows for receiving the initial and output of the processed grain material installed with an inclination from the front wall to the rear while rotary barriers are installed across the side walls above the supporting grid with a variable gap, and a protective grid is installed under the supporting grid, the common the area Ω of which is larger than the total area S of the supporting grid and satisfies the inequality 2Ω> S, and the throughput of the grids to the upward air flow is related to the cell size in the clearance of the grid and satisfies the inequality f · h> j · k, where

f is the cell width in the lumen of the protective mesh;

h is the cell height in the lumen of the protective mesh;

j is the cell width in the lumen of the supporting grid;

k is the height of the cell in the lumen of the supporting grid.

The pneumatic separator further comprises a filter fixed to the outlet window of the fan and to the housing of which is attached a drive with a self-regulating valve for unloading impurities, which opens under the action of gravity of the contents in the mass storage device. That is, the accumulation and removal from the pneumatic separator of light particles suspended in the air is carried out using a drive with a self-regulating valve for unloading impurities.

It was possible to maintain a stable distribution of the speeds of soaring of the components of the grain mixture in the upward air flow during long-term operation by placing a protective net in front of the supporting grid and installing a drive with a self-regulating valve for unloading impurities.

In an operational study, a grain mixture of 13 kg and a moisture content of 12.8% was divided, consisting of barley grains (main material) with an average weight of 1000 grains 44.62 g and oats (impurity) in the amount of 12866 pcs. with an average weight of 1000 grains of 35.14 g.

As a result, with 100% oat isolation, barley loss was 25.4%, and the separation efficiency remained at 79.7%. The maximum separation efficiency was 68.8% with a barley loss of 12% and an oat isolation of 98.8%.

Preservation during long-term operation in stable states of the density of the grain flow processed in the channel entering the channel through the receiving window and weighed by the upward air flow is achieved by the fact that light impurities located in the environment above the supporting mesh are absorbed and adhere to the surface of the protective mesh, keeping the throughput constant supporting grid ability. Since the total area of the protective net is two times larger than the total area of the supporting net, even with a significant cover of a certain part of the area of the protective net, a balance is maintained between the air entering and leaving the grain cleaner.

By installing a protective grid and a drive with a self-regulating valve for unloading impurities, the required density stability of the processed grain flow over the entire depth of the channel is ensured for the long-term operation of the grain cleaner, which is the main condition for a uniform field of air flow velocities and, therefore, high efficiency of the process of separation of grain material.

The efficiency of the grain cleaner, the stability of the quality indicators of the separation process during long-term operation, the reliability of the technological process are provided by rational ratios linking the main parameters of the protective mesh and the accumulator with a self-regulating valve.

The invention is illustrated by drawings, where figure 1 presents the technological scheme of the pneumatic separator with rotary barriers; figure 2 is a General view of the air separator with rotary barriers (front view); figure 3 is a General view of the air separator with rotary barriers (right side view); figure 4 is a side view of the drive with a self-regulating valve discharge of impurities; figure 5 is a front view of the drive with a self-regulating valve discharge of impurities; Fig.6 is a view A of Fig.5; Fig.7 is a top view of the drive with a self-regulating valve discharge of impurities.

In the case of the pneumatic separator there is a channel for separating grain by an upward air flow formed by the front 1, rear 2, and side 3 and 4 walls, and contains a supporting grid 5 for supporting the separated material, a feed hopper 6 and a window 7 for inputting the source material into the channel, made in front wall 1 above the net 5, and an unloading hopper 8 with a window 9 for outputting the heavy fraction from the channel at the opposite rear wall 2. Above the net 5 across the side walls 3 and 4, rotary barriers 10 are installed.

Under the mesh 5, a protective mesh 11 is installed, made of steel rods with a diameter three times smaller than the width of the lumen cell.

The material to be separated (feed material — difficult to separate impurities) is accumulated in the discharge means 12, where, under the action of the mass of accumulated grain, a self-regulating valve 13 opens, due to which the mass of accumulated grain is brought out.

Small particles suspended in the air (dust, etc.) are absorbed by the radial fan 14 and accumulated in the filter element (not shown), secured with a clamp to the filter housing on one side (above), and on the other, a drive clamp with a self-regulating valve discharge of impurities (not shown).

The pivoting barrier 10 is attached to the side walls 3 and 4 of the channel with a rod 15 extending in the center of the pivoting barrier 10. The angle of rotation of the pivoting barrier 10 is controlled by a handle 16.

The swing barriers 10 are mounted above the grid 5 with a clearance sufficient for passage of the processed grain material along the inclined grid 5.

The regulation of the amount of supplied grain material is carried out by the handle 17.

Pressure regulation of the ascending air flow in the channel of the pneumatic separator is carried out by the handle 18.

A drive with a self-regulating valve for unloading impurities consists of a latch 19, a cover 20, a bottom plate 21, a side wall 22, an arc 23, a front plate 24, a ring 25, an upper ring 26, an upper plate 27, an attachment ear 28, a hook 29, an ear 30, a gauge rod 31 with a diameter of 6 mm, a length of 260 mm, a woven wire wall (d = 1.2 mm) with square cells of normal accuracy No. 2.

The workflow is as follows.

The initial grain material, consisting of grain and subject to separation of lighter impurities than grain, is fed into the channel through the feed hopper 6 and window 7, where it is exposed to upward air flow, pumped from below the channel through the protective 11 and supporting 5 mesh or sucked from above any air flow generator (radial fan). As a result of upward air flow, the grain material acquires the state of a fluidized bed and 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 flow, and heavier particles (main grain) remain in the lower layers of the processed material stream above the supporting grid 5, touching it to one degree or another depending on the air flow velocity.

When such a fan-shaped flow of grain material meets the first pivoting barrier 10, its lower layers, consisting mainly of grain, stop moving towards the rear wall 2, drop downward on a layer 5, where the process of further isolation of light particles resumes. The top layer, consisting of 35% of the grain, before the impact is directed at an angle of 90 ° to the common tangent drawn to the impacting bodies at the point of impact. This grain flow, having descended on the grid 5, creates a higher than fan-shaped resistance to the air flow passing through it in the area between the first and second rotary barriers 10, thereby reducing the speed of the air flow, bringing it closer to the level as in the area of the grid 5 between the front wall and the first swing barrier 10.

Another part of the grain material, located at higher and less dense levels of the grain flow and containing more light particles, smoothly, without injuries, is reflected from the surface of the rotary barrier, after which the grains are lowered onto the grain stream, and light difficult to separate impurities are raised by the air stream and accumulate in the feed hopper of the feed grain, light suspended particles are carried out of the channel through the upper outlet into the filter element and accumulate in the drive with a self-regulating valve.

Another part of the flow of the processed material, moving above the rotary barrier 10, continues to move in the air flow up to the exit and to the rear 2 wall of the channel. This part of the stream contains predominantly light particles.

In the section of the channel between the first and second pivoting barriers 10, the process of separation of the material fed to the supporting grid 5 into the gap between the supporting grid and the first barrier is carried out in the same way as in the section between the front 1 wall and the specified pivoting barrier 10.

The second rotary barrier 10, like the first, deposits the main part of the grain flow on the supporting grid 5 with a layer, increasing its resistance to air flow and stabilizing its speed in the final section of the channel between the second rotary barrier 10 and the rear wall 2.

As a result of the creation of favorable conditions for the air flow velocity over the entire depth of the pneumatic separation channel with rotary barriers, the distribution speeds of the components of the grain mixture in the upward air flow are uniformly distributed over a long operating time (protective mesh) and the cleaning stability is maintained as it accumulates in a drive with a self-regulating valve .

The proposed device allows to reduce the influence of external factors (clogging of the supporting grid by foreign particles and excessive clogging of the filter element with light impurities) on the uniform distribution of the speeds of the components of the grain mixture in the ascending air flow over a long period of operation and to increase the production of biologically valuable seeds of agricultural crops.

Claims (2)

1. A pneumatic separator, characterized in that it contains rotary barriers, a channel for separating grain with an upward air flow formed by the front, rear and side walls and containing a support grid and windows for receiving the initial and output of the processed grain material installed with an inclination from the front wall to the rear while rotary barriers are installed across the side walls above the supporting grid with a variable gap, and a protective grid is installed under the supporting grid, the total area Ω of which is greater Chez total area S and the supporting grid satisfies 2Ω> S, wherein the bandwidth grids updraft associated with a mesh size in the lumen of the grid and satisfies f · h> j · k, where
f is the cell width in the lumen of the protective mesh;
h is the cell height in the lumen of the protective mesh;
j is the cell width in the lumen of the supporting grid;
k is the height of the cell in the lumen of the supporting grid. 2. The pneumatic separator according to claim 1, characterized in that it contains a filter fixed to the outlet window of the fan and to the body of which is attached a drive with a self-regulating valve for unloading impurities, which opens under the action of gravity of the contents in the mass storage device.

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