RU2453381C1 - Method of impact cleaning of sieve from stuck particles of separated material - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture, in particular to methods of impact cleaning of holes of sieve from stuck particles of separated material in grain cleaning machines, and can be used in other fields of national economy that use sieve machines for separation of bulk materials. The method of impact cleaning of sieve from stuck particles of separated material includes striking from above of an inclined, horizontal oscillating sieve with an electromagnetic bumper. Strikes are made at a time when the sieve under horizontal oscillations comes to an extreme position in the direction of separated material. The signal is set to the bumper in advance. The frequency of the strikes is equal to the frequency of horizontal oscillations or less from two to seven times. The force of the bumper strike on the surface of the sieve varies from 40 N to 250 N at the time of strike of 3·10^-3 s.

EFFECT: improvement of quality of separation of separated material, increasing the productivity of grain cleaning machine and reduction grain traumatising.

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Description

The invention relates to agriculture, in particular to methods for impact cleaning of sieve openings from jammed particles of separated material in grain cleaning machines, and can be used in other sectors of the national economy using sieve machines for separating bulk materials.

A known method of impact cleaning the sieve from jammed particles of separated material, in which the hammer is driven from the sieve mill, and the blows are applied from the top to the center of the sieve at each horizontal oscillation of the sieve mill at the moment when the sieve mill, with its horizontal vibrations, approaches the extreme position in the direction of movement separated material [1].

The disadvantages of this method are the inability to change the impact force of the striker without stopping the entire machine, as well as the inability to independently reduce the frequency of impacts, since it is rigidly connected with the frequency of horizontal vibrations of the sieve mill, which increases the impact on the sieve and the separated material and leads to increased injury grain.

The closest adopted for the prototype is a method of impact cleaning the sieve from jammed particles of separated material, in which strikes with a frequency of 350-600 count / min and an amplitude of 0.3-1.0 cm are applied from above on an inclined, horizontally oscillating sieve with an electromagnetic impactor [2, 3].

This method has the following disadvantages: it is not possible to change the impact force of the striker on the surface of the sieve, the moment of impulse to the striker is not consistent with the position of the sieve mill during its horizontal vibrations, which requires overestimating the impact force, since the impact of inertial force is ineffective when striking the sieve holes arising from its horizontal vibrations [1]. This force acts on the jammed particle and helps to release it from the sieve opening when striking at the moment when the sieve during horizontal vibrations approaches the extreme position in the direction of movement of the separated material and counteracts the release if the blow is applied when the sieve is in the opposite movement of the separated material extreme position.

The invention is aimed at improving the impact cleaning of the sieve, namely, reducing the frequency and strength of impacts on the sieve and the material being processed during impact cleaning of its openings from jammed particles of separated material, and reducing grain trauma.

A method of shock cleaning the sieve from jammed particles of the separated material is proposed, including striking from above on an inclined, horizontally oscillating sieve using an electromagnetic striker, characterized in that the blows are carried out at the moment when the sieve approaches the extreme position in the direction of movement of the separated material, moreover, the signal to the drummer is advanced, while the frequency of impacts is equal to the frequency of horizontal vibrations or lower from two to seven times, and the force of impact the impactor's height on the surface of the sieve varies from 40 N to 250 N at an impact time of 3 · 10 ^-3 s.

In the proposed method, when cleaning the holes of the sieve, an inertial force is applied, which acts on jammed particles during horizontal vibrations of the sieve mill, this ensures a decrease in the value of the impact force, and consequently, the trauma of the separated material.

The proposed method allows you to change the impact force of the striker from 40 N to 250 N when using it in an automatic control system with more accurate selection of the impact force, while improving the quality of cleaning the sieve, increasing the contact time of the separated material and the surface of the sieve, and therefore, increasing the performance of grain cleaning cars.

Figure 1 shows a diagram of the method of impact cleaning the sieve from jammed particles of the separated material, figure 2 shows the forces acting during impact on the grain particle jammed in the hole of the sieve at the moment when the sieve approaches horizontal position in the direction of movement of the separated material.

The impact cleaning system of the sieve contains an electromagnetic drummer 2 in the center above the surface of the sieve 1 (Fig. 1), the drummer control device 3, the sieve is fixed in the sieve mill 9, the crank 8 of the horizontal oscillation drive of the sieve mill with a metal tongue 7, an inductive sensor 6, a hopper for separated material 5 with a valve 4, n is the frequency of horizontal vibrations of the sieve mill, φ is the lead angle.

On jammed grain particle 10 in the opening of the sieve 1 with an angle of inclination β (figure 2) the following forces act: F _t - gravity; F _h - force particles jamming in the hole; F _and - the force of inertia acting on the particle during the impact; F _ik is the inertia force acting on the particle during horizontal vibrations and the projection of the inertia and gravity forces on the coordinate axis Y, y is the sag deflection after the impact.

The method is implemented as follows.

At an angle β to the horizon, a sieve 1 is installed (Fig. 1), which, together with the sieve mill 9, performs horizontal oscillations with a frequency n using a crank 8. One revolution of the crank corresponds to one horizontal oscillation of the sieve mill. On the sieve 1 from the hopper 5 through the slot formed by the valve 4, is fed the processed material. During the operation of the grain cleaning machine, particles of the processed material that are close in size to the dimensions of the sieve holes are jammed in these holes. With horizontal vibrations of the sieve, the inertia force F _and acts on the particle jammed in its hole (Fig. 2), since the sieve is set at an angle β to the horizontal, when it approaches the extreme position in the direction of separation of the material to be separated, the projection of this force F _iku on the axis Y is directed towards the wedging and the force helps to release the particle from the hole. To clean the holes on top of the sieve striker 2 strikes. To use the force F _ik and reduce the impact force on the surface of the sieve, it is applied at the moment when the sieve at horizontal vibrations approaches the extreme position in the direction of movement of the separated material.

The particle wedges, releases the hole and goes off the surface of the sieve, provided:

F _and + F _iku > F _tu + F _s .

To coordinate the moment of impulse feed to the drummer with the position of the sieve mill during its horizontal vibrations, an inductive sensor 6 is mounted on the frame of the grain cleaning machine next to crank 8. A metal lobe 7 is mounted on the crank, which rotates around the sensitive organ of the inductive sensor. At this moment, a signal is generated that goes to the drummer control device 3, in which a frequency divider with a variable division ratio is installed, the division ratio is set manually from 1 to 7. After that, an impulse is sent to the drummer. The impact force of the striker on the sieve surface varies from 40 N to 250 N at a stroke time of 3 · 10 ^-3 s, by changing the voltage supplied to the striker or by changing the duration of the electric pulse to the striker. For accurate striking at the moment when the sieve, when horizontal vibrations approaches the extreme position in the direction of movement of the separated material, the signal from the sensor must arrive ahead of time necessary for the actuation of the drummer control device and acceleration of the striker. The sensor is installed at an advance angle φ relative to the metal lobe 7 in the extreme position of the sieve in the direction of movement of the separated material, which is calculated by the following formula:

φ = 2 · π · n · (t _y + t _e ),

where φ is the lead angle, rad;

n is the frequency of horizontal vibrations, 1 / s ^-1 ;

t _y is the time required to accelerate the striker, s;

t _e - time required for operation of the control device, s.

Thus, the proposed method of impact cleaning the sieve from jammed particles of the separated material reduces the impact of impacts on the sieve and the processed material and reduces the trauma of individual grains. By reducing the frequency and strength of impact during impact cleaning, the contact time of the processed material with the surface of the sieve increases, and therefore, the productivity of the grain cleaning machine and the separation quality of the separated material are increased.

Information sources

1. Drozdetsky Yu.A. Improving the efficiency of the separation process on sieves with longitudinal vibrations by using impact cleaning of their holes. Dis. Cand. tech. sciences. - Kurgan, 2003 .-- 167 p.

2. Patent RU 2223826, cl. B03C 7/02.

3. Shmigel VV Separation and stimulation of seeds in an electric field. - Kostroma: ed. KSAA, 2003 .-- 234 p.

Claims (1)

A method of shock cleaning the sieve from jammed particles of the separated material, including striking from above on an inclined, horizontally oscillating sieve using an electromagnetic striker, characterized in that the blows are carried out at the moment when the sieve approaches the extreme position in the direction of movement of the separated material, and the signal to the firing pin is advanced, with the frequency of impacts equal to the frequency of horizontal vibrations or lower from two to seven times, and the impact force of the firing pin and on the surface of the sieve varies from 40 N to 250 N at an impact time of 3 · 10 ^-3 s.

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