UA44591A - DEVICE FOR SCREENING MATERIALS - Google Patents

Abstract

An apparatus for screening materials includes a vertical channel in which screening surfaces are placed zigzag-like, one under another, deflectors, located under the screening surfaces with a gap, a loading device and manifolds for removing separated fractions. The shape of the vertical channel is described by the equation of harmonic oscillations by sine law, where each half-wave is formed by two vibroexciting surfaces: the screening surface consisted of flexible vibroexciting cylindrical grate-bars, which are supported as a cantilever with a constant gap and bent along the sinusoid curve of the vertical channel, and the deflector consisted of the flexible vibroexciting sheet, which is supported as a cantilever and has a shape of a section of the sinusoid curve of the vertical channel.

Description

The invention relates to the separation of materials using sieves and can be used in the metallurgical, mining, and chemical industries.

The famous grate rumble | 1), which includes gratings of a curvilinear shape, hinged on a fixed axis, which are attached to an additional flexible axis, which is installed with the help of an elastic connection on the supports. The disadvantage of the known design is that the grates can vibrate only in the low-frequency range, in the vertical plane and only relative to their axes of rotation. This deteriorates the quality of screening, and also prevents the screen from working when screening fine-grained material. In addition, the known structure of the screen has insufficient reliability because the flexible screen is installed with the help of an elastic connection on the supports.

The closest technical solution, chosen as a prototype, is the bulk material separator |21, which consists of a vertical channel in which sieving surfaces are installed in a zigzag manner, one below the other, deflectors located under the sieving surfaces with a gap, a loading device and outlet nozzles distributed fractions. The sieving surfaces in the known device are made in the form of cantilevered fingers.

The disadvantage of the known design is that the zigzag-shaped sieving surfaces do not ensure effective distribution of materials on the sieving surfaces, where counterflows of material occur, stagnation zones are created, which leads to cluttering of the passage section of the vertical channel. In addition, this arrangement of screening surfaces does not allow creating the optimal frequency and amplitude of forced oscillations of the material in the vertical channel, which also reduces the quality and reliability of the screening process.

Making the screening surfaces in the form of cantilevered fingers does not provide for their vibration with the required frequency and amplitude due to the influence of the gravitational forces of the material moving in the vertical channel, which also does not ensure the quality of screening required, especially for materials with increased moisture.

The performance of the deflector as a guide sheet also reduces the quality of material screening, because it does not take part in the formation of the flow of material moving along the vertical channel and does not exert a vibrating influence on it.

The constancy of the opening between the screening surface and the deflector along the entire length of the vertical channel leads to a decrease in screening productivity, which is determined by the cross-section plane of the upper part of the vertical channel, while in the lower part of the channel the amount of material that passes through the screening surfaces is sharply reduced.

The invention is based on the following task: 1. Improving the quality of screening. 2. Reduction of energy consumption.

Z. Increasing the reliability of screening.

In the proposed invention, this task is solved with the help of the fact that in a device for sieving bulk materials, which has a vertical channel in which the screening surfaces are installed in a zigzag manner, one below the other, deflectors located under the screening surfaces with a gap, a loading device and nozzles to derive the distributed fractions, according to the solution, the shape of the vertical channel is described by the equation of harmonic oscillation, changing according to the sine law, where each half-wave is formed by two vibration-exciting surfaces: a screening one, consisting of cantilever-mounted flexible vibration-exciting cylindrical grates, bent along the arc of a sinusoidal curve of the vertical channel , and a deflector, which is a cantilever fixed flexible vibration exciting sheet, which has the shape of a part of the arc of a sinusoidal curve of a vertical channel. In addition, the vertical channel along its entire length has a variable cross-section that decreases in the direction of the nozzle for extracting the distributed fractions, and the deflector has a grating vibration limiter, which is located from the end of the grating of the upper sieving surface at a distance equal to the maximum amplitude of its oscillation.

Comparison of the claimed device with the prototype shows that the shape of the vertical channel is new, which is described by the equation of harmonic oscillation carried out according to the sine law. During the wave movement of the material from top to bottom along the vertical channel, there are no oncoming flows that do not form stagnation zones, there is no cluttering of the passage section of the vertical channel, which ensures the most effective distribution of the material into fractions. The formation of each half-wave of the vertical channel by two vibration-exciting surfaces ensures the creation of optimal dynamic loads on the material to be sorted, which contributes to the improvement of the screening quality of the material.

The execution of the vibrating screening surface in the form of cantilever fixed cylindrical grates with a constant gap, concave along the arc of the sinusoidal curve of the vertical channel, ensures the vibration of the grates with the required frequency and amplitude from the influence of the gravitational forces of the material falling on the sieving surface.

The design of the deflector in the form of a cantilever fixed flexible vibrating sheet, having the shape of a part of the arc of a sinusoidal curve of a vertical channel, which provides a high-frequency dynamic impact on the material, which is directed to the sieving surface, which leads to additional vibration of the material.

The presence of a deflector limiter of vibrations of the gratings of the upper screening surface ensures the reliability of the device design when the vibration amplitude of the gratings exceeds the maximum permissible value. The execution of a vertical channel with a cross-section variable in length, which reduces in the direction of the nozzles the fate of the output of separated fractions, allows to increase the productivity of the device while ensuring a constant vibration effect on the material along the entire height of the vertical channel.

In fig. 1 shows a longitudinal section of the screening device, in fig. 2 shows a grating vibrating sieving surface, a side view, and in fig. From the front view, in fig. 4 shows a vibration-exciting deflector, a side view, and fig. 5 front view.

The device for sieving consists of a receiving hopper 1, a vertical channel of variable cross-section 2, grating vibrating sieving surfaces 3, vibrating deflectors 4, nozzles for the output of distributed material fractions 5. The vibrating sieving surface 3 is made in the form of flexible cylindrical gratings 7, cantilevered on collectors 6.

Vibro-exciting deflector 4 is made in the form of a cantilever-fixed flexible sheet 9, a limiter of grating vibrations 8, a guide surface of sifted material fractions 10 and a groove for a collector of a vibro-exciting screening surface 11.

The device for screening materials works as follows.

The material to be sorted is fed in portions to the receiving hopper 1, where under the action of its own weight it moves along the vertical channel of variable cross-section 2 onto the grating vibration-exciting surfaces 3. As a result of the dynamic impact of a portion of the material against the elastic gratings, which are cantilevered with a constant gap, the latter begin to oscillate with the required frequency and amplitude, which depends on the mass and frequency of serving a portion of the material. Particles of material with a size smaller than the gap between the gratings of the sieving surface pass through the sieving surface and, under the action of their own weight, move along the straight surfaces of the deflector 4 to the nozzles for the output of separated fractions 5. Particles of material with a size greater than the gap between the gratings of the sieving surface, and also the particles of the fine fraction that did not have time to be removed on the first sieving surface are transferred to the next ones, where the described sieving process is repeated. The number of sieving surfaces depends on the desired degree of purity of the screening material and its initial fractional composition. Large particles of material, passing under the influence of their own mass along the vertical screening channel and interacting

With all sieving surfaces, they are directed to the nozzles for the output of the distributed fractions.

Excitation of vibrations of the grates of the sieving surface due to the use of the forces of gravity of the falling material ensures effective self-cleaning of the sieving surface, which makes it possible to screen fine fraction materials with increased humidity.

Excitation of oscillations of cantilever-fixed flexible vibration-exciting sheets in deflector 4 provides a high-frequency dynamic impact on the material directed to the sieving surface

With, which also increases the efficiency of the debiting process. When the permissible value of the amplitude of vibrations of grates 7 is increased, the latter hit the vibration limiters 8 of the deflector 4, which provides protection of the device against overload. When moving the sorted material along the vertical channel of variable section 2, the constancy of the volume of the material between each sieving surface and the deflector is ensured, which increases the productivity of the device while providing a constant vibration effect on the material along the entire height of the vertical channel.

The use of the proposed device for sieving materials will significantly improve the quality of sieving of fine-fraction materials with high humidity, while the energy consumption of the sieving process will decrease by 3-5 times, and the material capacity of the screening structure will decrease by 2-3 times.

Sources. 1. A. p. 761031 USSR, MKV, VO7B81/28, Grokhot /V. A. Semenov, V. I. Sorokin, V. D. Nosik, E. P.

Yablukov, V. I. Tyutyunnyk. - 1960533/ 29 - 03; Application 26.09.1973; Publ. 09/07/1980. Inventions.

Industrial samples. Trademarks. - 1980. Mo. 33.- S. 29. 2. A. b. 2071389 Russia, MKV, В0О781/04. Separator of bulk materials /А. N. Zyulin, V. I. Aniskin. - 94027767/ 03; Application 25.07.1994. Publ. 10.01.1997. Inventions. Industrial samples. Trademarks. - 1997. Volume 1. - P. 157.

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Claims (2)

1. A device for sieving materials, including a vertical channel in which sieving surfaces are arranged in a zig-zag manner one below the other, deflectors located under the sieving surfaces with a gap, a device for loading and nozzles for the output of distributed fractions, which is distinguished by the fact that the shape of the vertical channel is described by the equation of harmonic oscillation carried out according to the sine law, where each half-wave is formed by two vibration-exciting surfaces: a sieving surface consisting of cantilevered flexible vibration-exciting cylindrical grates with a constant gap, bent along the arc of a sinusoidal curve of a vertical channel, and a deflector consisting of cantilever fixed flexible vibrating sheet, which has the shape of a part of the arc of a sinusoidal curve of a vertical channel. 2. The device according to claim 1, which differs in that the vertical channel along its length has a variable section, which decreases in the direction of the nozzles for the output of the distributed fractions. C. The device according to claim 1, which is characterized by the fact that the deflector has a limiter of vibrations of the grates, which is located from the end of the grates of the upper screening surface at a distance equal to the limit amplitude of its vibrations.