RU2266165C1 - Centrifugal pneumatic separator for cleaning grain material - Google Patents

Abstract

FIELD: apparatuses for cleaning grain materials, possibly in agricultural production.

SUBSTANCE: centrifugal pneumatic separator includes annular pneumatically separating duct provided with lower branch pipe designed for introducing rising air flow and for discharging cleaned grain material; and with upper branch pipe for draining from said duct waste air flow with light impurities; rotary cone spreader and loading branch pipe for supplying grain material to be cleaned. Spreader includes row of cones secured to common shaft and mutually spaced by some distance. Upper branch pipe includes regulation damper. In bottom each of said cones except last one has central opening. Upper cone has maximum diameter and the most diameter of opening. Next cones (from upward to downward) have gradually reduced diameters.

EFFECT: improved cleaning degree of grain material, lowered loss of high-quality grain with air-separated light impurities.

1 dwg

Description

The invention relates to a device for cleaning grain material and can be used in agricultural production, in the flour and grain elevator and animal feed industry.

Known pneumatic separation devices with channels of rectangular, circular and annular cross-section, in which the separation of grain material into fractions occurs by "weighing" the particles [1]. The air velocity in these devices does not exceed the critical velocity of heavy particles. A significant drawback of these pneumatic separation devices is the relatively low specific load on the channels, limited by the mass (critical speed) of heavy particles. Therefore, these devices have a low specific throughput.

A centrifugal-pneumatic separator is known, consisting of a loading nozzle, an annular pneumatic separating channel, a rotary conical spreader, a cone mounted on a shaft, a device (nozzle) for introducing air into the pneumatic separating channel and withdrawing purified grain material from it, a loading nozzle and a nozzle for exhausting the spent air with light particles [2].

When the separator is operated with a rotary conical spreader rotating around a vertical axis, a fan-shaped annular jet of processed grain material is introduced into the pneumatic separating channel, which is affected by an upward air flow, which results in separation of the material into two fractions - light impurities and a purified product.

According to the design and technological process, the same centrifugal-pneumatic separator has an air-sieve machine MZP-50 for primary cleaning of grain material [3].

The technical nature and the totality of the essential features of a centrifugal-pneumatic separator is closest to the claimed separator, and it is taken as a prototype. The disadvantage of this centrifugal-pneumatic separator is the low cleaning effect of the grain material, which is explained by the following. Since the pneumo-separating channel has an annular shape, the concentration of grain material (“density” of the grain stream) is greatest in the area adjacent to the spreader, and as it approaches the outer wall of the channel, it decreases and has the least value near this wall. As a result of this, the resistance to the air flow movement in the radial and, therefore, in the annular directions of the channel is uneven, and the air velocity in these directions is also uneven: it has the smallest value on the spreader, and the greatest on the outer wall of the channel. For this reason, in the channel zone adjacent to the spreader, there is no effective separation of light impurities from the processed grain material, as a result of which its cleaning effect is reduced. In addition, with the marked distribution of the grain material and the air flow rate in the channel, full grain is removed to the waste fraction (with light impurities) from the zone adjacent to the outer wall of the channel.

Along with the noted prototype - the separator is inherent in the following disadvantage. Since the air flow into the separator is introduced through openings made on the upper part of its casing - at the level of the spreader, and is discharged by means of a pipe located also in the upper part of the casing and connected to the sedimentation chamber, with this design of the air system, the air flow affects the grain being processed the material is practically only in the zone of its exit from the loading window (pipe) and, as a matter of fact, does not affect the fan-shaped annular stream of material coming down from the spreader. In addition, when placing the outlet pipe in the radial direction, the uniformity of the air velocity field is dissipated, as a result of which an axisymmetric "working" air stream is not achieved, which also reduces the effect of cleaning the grain material from light impurities.

The problem that needs to be solved is to achieve a uniform distribution of the grain material in the working area of the air separation channel - in the radial and annular directions.

The problem is solved using the proposed centrifugal-pneumatic separator, the pneumatic separating channel of which is circular, and in the upper part coaxially with the spreader there is an upper nozzle with an adjustment flap installed in it, designed to withdraw the exhaust air flow from the pneumatic separating channel with light impurities emitted from processed grain material. In addition, the separator spreader consists of several cones fixed at some distance from each other on a common shaft, with the upper cone having the largest diameter, and the diameter of subsequent cones gradually decreasing. At the bottom of the cones, with the exception of the last - lower, a central hole is made, with the upper cone having the largest diameter, and the diameter of the hole for subsequent cones gradually decreasing.

A diagram of a centrifugal-pneumatic separator for cleaning grain material is shown in the drawing.

A centrifugal-pneumatic separator for cleaning grain material consists of an annular pneumatic separating channel 1 with a lower nozzle 2 that introduces air into the channel 1 and removes purified grain material from it, and an upper nozzle 3 that removes the exhaust air stream with light impurities from channel 1; a rotary conical spreader and a loading nozzle 4 supplying the processed grain material to it. The upper branch pipe 3 is placed on the upper part of the annular channel coaxially with it, and the adjustment valve 11 is installed in the branch pipe. The spreader has a number of cones fixed at some distance from each other on the shaft 5. Three cones are shown in the diagram: upper 6, middle 7 and lower 8 The largest diameter has the upper cone 6, and the diameter of subsequent cones gradually decreases. At the bottom of the upper 6 and middle 7 cones, the central holes 9 and 10 are respectively made, while the diameter of the hole 9 is larger than the diameter of the hole 10.

The operation of the centrifugal-pneumatic separator proceeds as follows. From the loading pipe 4, the grain material to be cleaned is supplied to the rotating upper cone 6; from it, part of the material under the action of centrifugal force is introduced into the annular pneumatic separating channel 1, in which it is exposed to an upward flow of air entering the channel 1 through the lower pipe 2. Another part of the grain material through the opening 9 of the cone 6 is fed to the rotating cone 7, from which also part of the material enters the pneumatic separation channel 1, in which an air flow acts on it. The rest of the material from the cone 7 through its hole 10 is directed to the rotating lower cone 8, from which it is fed into the pneumatic separation channel 1.

In the pneumatic separation channel 1, light impurities are released from the grain material from the grain material, which are removed from the separator through the upper nozzle 3. Subsequently, this two-phase mixture “air - light impurities” enters, for example, a centralized air system for air purification (the system is not shown in the diagram) ) Purified from airborne impurities, the grain material from the air separation channel 1 is discharged through the lower pipe 2.

The execution of the channel 1 annular contributes to a uniform supply of air flow into the separation zone of the grain material, as a result of which a uniform pressure field and, consequently, air flow rates are achieved in this zone, thereby improving the conditions for the release of light impurities from the processed grain material. The achievement of this effect is also facilitated by the placement of the upper nozzle 3 on the upper part of the annular channel 1 coaxially with it: with this installation of the nozzle 3, the exhaust air outlet with light impurities does not distort the uniform field of air velocities in the separation zone of the grain material.

With the noted pattern of change in the diameter of the cones 6, 7 and 8 by the upper 6, the grain material is introduced into the annular zone of the channel 1 adjacent to its outer wall, the middle cone 7 into the middle annular zone of the channel 1, and the lower cone 8 into the annular zone adjacent to the inner wall of this channel. Thanks to this introduction of the grain material, a uniform distribution of its particles is achieved in the working area of the air separation channel 1, as a result of which a greater effect of the release of air-separated (light) impurities is achieved, i.e. increases the purity of the processed grain material. In addition, with the noted process of cleaning grain material, the removal of full-fledged grain with air-separated impurities decreases, i.e. its losses are reduced.

Depending on what airborne impurities are contained in the processed grain material (dust, flooring, particles of straw and leaves of cultivated plants, punctured and crushed grain of the main crop) and what the processed material is intended for (seed, food and feed grain), the air flow rate pneumatic separation channel 1 is changed by turning the adjusting flap 11.

Thus, during the operation of the proposed centrifugal-pneumatic separator, a positive effect is achieved, which consists in increasing the purity of the processed grain material and reducing the loss of full grain.

Literature

1. Malis A.Ya., Demidov A.R. Machines for cleaning grain by air flow. - M .: Mashgiz, 1962 .-- 176 p.

2. Goncharov B.C., Grabelkovsky N.I. Centrifugal-pneumatic separator for grain materials // Tractors and agricultural machinery. - 1968. - No. 6. - S.26-28.

3. Machines for post-harvest grain processing / B.C. Oknin, I.V. Gorbachev, A.A. Terekhin, V.I. Soloviev. - M .: Agropromizdat, 1987 .-- 239 p.

Claims (1)

A centrifugal-pneumatic separator for cleaning grain material, containing a pneumatic separating channel with a lower nozzle for introducing air flow into it and outputting purified grain material, a loading nozzle for introducing cleaned grain material, a nozzle discharging exhaust air with light impurities and a rotary conical spreader for feeding grain material into the pneumatic separating channel, characterized in that the pneumatic separating channel is made annular, and the nozzle with the adjustment a throttle valve that discharges exhaust air with light impurities is placed in the upper part of the channel and coaxial to it, and the spreader is equipped with at least two cones fixed at some distance from each other on a common shaft, while on the bottom of the cones, with the exception of the lower , a central hole is made, the largest diameter and diameter of the hole has an upper cone, and for subsequent cones in the direction from top to bottom, these diameters gradually decrease.