RU2207920C1 - Device for separation of loose mixture - Google Patents

Abstract

FIELD: farming; food-processing , chemical and other industries. SUBSTANCE: proposed device includes bin, working member made in form of cone with orienting chutes on its surfaces, nozzle for delivery of air flow, ready fraction receivers, vibration exciter and excessive pressure source. Vibration exciter is made in form of pneumatic flow-through chamber whose inlet is connected with air excessive pressure source through throttle valve of varying section. Located at outlet of flow-through chamber is nozzle made in form of two flat circular plates; upper plate is mounted for displacement relative to lower one and is rigidly connected with taper working member. EFFECT: enhanced accuracy of separation; simplified construction; extended functional capabilities. 2 dwg

Description

 The invention relates to devices for air separation and can be used in agriculture, food, chemical and other industries.

 Known pneumatic separators for separating a granular mixture, including a feeder, a table with an inclined working surface, where the air flow is supplied from the fan (A.S. 994053, class B 07/4/02, 1981). Particles under the action of jets liquefy and flow into fraction collectors. The disadvantage of this device is the low quality of the separation of particles into fractions due to the fact that air jets act immediately on a large mass of seeds, the process proceeds in cramped conditions, the particles are practically in the aerodynamic shadow, which eliminates their clear separation by aerodynamic properties.

 Also known is a device for separating a granular mixture in a fluid medium, including a hopper, a working body with an inclined surface, nozzles for supplying an air stream, collectors of finished fractions, a source of excess air pressure with a drive (Patent 1502137, 1987, BI 31).

 Its disadvantages include design complexity, to generate control pulses of the pneumatic signal generator, a jet control system is used that includes NON-OR logic elements, the through-holes of which are often clogged with dust; when sorting the seeds, it becomes necessary to clean the air using filters. The design of the device does not allow the separation of seeds by aerodynamic properties.

 The task of the technical solution is to increase the accuracy of the separation of piece bodies by mass, expand the functionality of the device, simplify the design.

 The problem is solved in that in a device for separating granular mixture in a fluid medium including a hopper, a working body in the form of a cone with orienting grooves on its surface, a nozzle for supplying an air stream, collectors of finished fractions, a vibration exciter and an overpressure source, the vibration exciter is made in the form a pneumatic flow chamber, the inlet of which is connected through a throttle of variable cross-section to a source of excess air pressure, and at its outlet there is an annular nozzle in the form of two flat plates, the upper the plate is mounted with the possibility of movement relative to the bottom and is rigidly connected to the conical working body.

 In FIG. 1 shows a diagram of the proposed device, figure 2 is a section aa.

The device includes a hopper 1, an annular shutter 2, a working body in the form of a cone with orienting grooves 3, a vibration exciter made in the form of a pneumatic flow chamber 4, the inlet of which is connected through an orifice 5 of variable cross section to a source 6 of excess air pressure, and an annular nozzle is located at its output , consisting of two annular flat plates 7 and 8, and the upper plate is mounted with the possibility of movement relative to the lower and rigidly connected to the conical working body. The plates 7 and 8 are pressed against each other by means of a spring 9. The heavy, medium and light fractions accumulate in the annular receivers 10, 11 and 12, respectively. The pneumatic chamber 4 with plates 7 and 8, a choke 5 and an overpressure source together represent a high-frequency generator of pneumatic signals, the oscillation frequency of which is regulated by a choke 5 from tens to hundreds of hertz (in experiments up to 225 Hz). The oscillation period is determined by the time of filling and emptying the chamber 4. The working amplitude of the oscillations of the working body lies within (0.2 ... 0.3) 10 ^-3 m. Due to the fact that the diameter of the annular plate 8 is larger than the plate 7, the outflowing air sticks from the nozzle to the bottom plate, i.e. the Coanda effect is manifested, which consists in the fact that a stream of liquid (air) flowing along the surface is pressed against it by static environmental pressure (for example, a stream of water flowing out of an inclined glass adheres to its surface).

 When separating seeds by mass, the amplitude of the oscillations is chosen so that the thickness of the air stream in the initial section is less than the thickness of the seeds, which excludes the influence of their aerodynamic properties on the initial throwing speed and, therefore, the flight path (throwing distance).

 The workflow is as follows. At the initial moment, the gap between the plates 7 and 8 is equal to zero, as the chamber 4 is filled under the influence of excessive air pressure, the plate 7 together with the working body transfers the particles to a fluidized state, dramatically changing the rheological properties of the granular body. Particles acquire an acceleration greater than the acceleration of gravity, while the coefficient of internal friction is close to zero, which allows them to navigate one at a time in the grooves of the working body along the longitudinal axis. The jet emanating from the annular nozzle transfers the same amount of movement to the seeds (product of mass and speed), but since the seed flow has particles of different masses, they acquire different initial throwing speeds and fly along trajectories, depending on the acquired speed.

 To increase the throwing distance, the plate 8 is equipped with a flange on the periphery.

 With constant excess air pressure, the amplitude of the oscillations is automatically maintained at the same level, which is achieved by adjusting the compression ratio of the springs 9 and the air flow. The self-oscillating process is ensured by the fact that the area of air flow through the annular nozzle is significantly larger than the area of the orifice of the throttle 5, i.e. the expiration time from the chamber 4 is less than the time of its filling.

 The device is universal and can operate in the mode of separation of seeds by aerodynamic properties. To do this, in this way, the amplitude of the vibrations is changed so that the thickness of the air stream is greater than the thickness of the seeds, and the initial casting speed will be determined by the speed of the seeds.

 This technical solution allows during the pre-sowing preparation of seeds to select from the total mass of seeds with the highest absolute mass and field germination.

Claims (1)

 A device for separating a granular mixture in a fluid medium, including a hopper, a working body in the form of a cone with orienting grooves on its surface, a nozzle for supplying air flow, collectors of finished fractions, a vibration exciter and an overpressure source, characterized in that the vibration exciter is made in the form of a pneumatic flow a chamber, the input of which is connected through a variable-pressure inductor with a source of excess air pressure, and at its outlet there is a nozzle in the form of two flat annular plates, the upper the mud is mounted with the possibility of movement relative to the bottom and is rigidly connected to the conical working body.

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