RU2188721C2 - Vibratory screen - Google Patents

Abstract

FIELD: mining, construction and other branches of industry. SUBSTANCE: vibratory screen has frame, box-shaped casing mounted on frame, and vibratory exciter. At least one screening member made from flexible material is located in casing. Each screening member is composed of at least two rectangular sections arranged in imaginary broken line inscribed along generatrix arc and made in the form of regular or irregular polygon. Inclination angle of discharge section is multiple of five and makes β₁=(1-3)x5 deg, and inclination angles of subsequent sections make β_n = β_n-1+β₀, where β₀ is whole number of from 2 to 10 deg. Length of each section is equal to 1=2Rxsin 180 deg/n, where R is radius of generatrix arc of screening surface; m, n is number of sections of screening member. Vibratory screen of such construction is used for size separation of abrasive lump materials. EFFECT: increased efficiency in separating high-abrasive ground materials and simplified construction. 5 cl, 5 dwg

Description

 The invention relates to techniques for separating lumps of abrasive materials into particle size classes and can be used in the mining, construction industries and other industries.

A vibration sieve is known (USSR author's certificate 1260045, class MKI ⁶ V 07 V 1/40, publ. 09/30/86 - analogue), including a box inside which there is a grid made of interconnected sections installed at different angles to horizontally. Moreover, the interconnected sections of the grid are made in the form of pairs of triangles, and the vertices of one pair of triangles are located between the bases of adjacent pairs.

 The disadvantage of this technical solution is the low operational reliability of the screening surface of the mesh and the efficiency of screening of highly abrasive solid materials.

By its technical nature and the achieved result, the closest is a vibrating multi-screen screen (DE 2923662 A1 publ. 12/18/1980, class B 07 V 1/28 - prototype), including a frame mounted on the frame using vibration isolators box with placed in it, according to at least one screening surface in the form of a fragment of the side surface of a polyhedron of two or more rectangular sections located along a broken line, conditionally inscribed along the generatrix, with an angle of inclination of the discharge section of multiple 5 and the angles of inclination of subsequent seconds s = β _n β _n-1 + β _0, where β ₀ - integer in degrees exciter.

 The disadvantage of the prototype is the design complexity of the screen and significant material consumption, low efficiency of separation of the flow of solid materials.

 The technical result of the invention is to increase the efficiency of the separation of the flow of highly abrasive crushed material and increase the productivity of the screen.

The specified technical result is achieved by the fact that in a vibrating screen containing a frame, a case in the form of a box with at least one screening surface in the form of a fragment of the side surface of a polyhedron of two or more rectangular sections located along a broken line, arbitrarily inscribed in an arc forming with an inclination angle of the discharge section of multiple 5 and the angles of inclination of the subsequent sections β _n = β _n-1 + β ₀ , where β ₀ is an integer in degrees, vibration exciter, co According to the invention, the sieving surface is made of an elastic material in the form of a regular or irregular polyhedron, and the length of each section is made equal to l = 2R x sin180 / n, where
R is the radius of the arc forming a sieving surface, m;
n is the number of sections of the screening surface, and the angle of the discharge section β ₁ = (1-3) × 5 ^° , and β _o varies from 2 to 10 ^o .

 The vibrating screen is made of several screening surfaces located one above the other.

 Rectangular sections of the planes of the screening surfaces can be reinforced with elastic inserts and made of rubber or polyurethane with square, round or rectangular cells, while the oscillation vector (vibration) of the screening surface in the loading zone is directed towards the movement of solid material, and in the discharge zone - in the opposite . Hydraulic shock absorbers can be installed on the frame, at least from the discharge zone.

 The invention is illustrated and illustrated by drawings, in which Fig. 1 schematically shows a vibrating screen, Fig. 2 is a view A in Fig. 1, in Fig. 3 is a section BB of Fig. 1 is a fragment of a screening surface; 4 is a schematic diagram of the formation of the profile of the screening surface of the screen, figure 5 is an option for forming the profile of the screening surface of the screen.

 Vibrating screen (figure 1) contains a housing 1 with a loading device 2, and is installed on the inner frame 3 of the screen. The housing 1 and the frame 3 are connected by means of vibration isolators 4, symmetrically installed in the loading and unloading parts of the screen. The inner frame 3 is mounted on a vibration base 5, connected to the outer frame 6 of the screen by means of hydraulic shock absorbers 7 (Figs. 1 and 2). Between the outer frame 6 and the inner frame 3 are installed elastic shock absorbers 8. The outer frame 6 is installed on the base - the foundation (not shown).

 At least one eccentric vibration exciter 9 is mounted on the side surface of the housing 1 (Fig. 1), made in the form of a box (or a chute, cylinder), mounted on a shaft 10, which is driven by a drive (not shown). To adjust the amplitude and direction of the oscillation vector (vibration) of the housing 1, sockets (holes) 11 for setting unbalances (not shown) are made on the vibration exciter 9.

 A screening surface 12 is installed inside the housing 1, or several screening surfaces of the screen 12 and 13 consist of a set of separately installed rectangular sections 14 that are tightly adjacent to each other. Sections 14 (FIG. 3) are made of elastic wear-resistant material (for example, rubber or polyurethane), contain cells (holes) 15, jumpers 16, which are reinforced with elastic inserts 17 made, for example, of fiberglass, to increase the stiffness of the sections. Cells 16 are cone-shaped, expanding in the direction of the back plane T of sections 14 (in Fig. 3, the working plane P of sections is located above and the non-working plane of the back side T is at the bottom), and in the plan, cells 15 are square, round, or rectangular (slot ), the cell size is set taking into account the requirements of the screening technology of solid materials.

Как правило, для обеспечения требований технологии грохочения, количество n плоскостей K_n просеивающей поверхности 12 вибрационного грохота равно n=2÷5 (на фиг.1 количество плоскостей n=4). Результирующий угол Θ₁ наклона просеивающей поверхности 12 дуги ВВ определяется с учетом требований технологии грохочения.The screening surface 12 is formed in the form of cavities by fixing several rectangular sections 14 along the broken line of the arc BB of a circle of radius R ₁ from the loading zone to the discharge of the screen (figure 4). The sieving surface 12 is a fragment of a regular polyhedron with planes K _p (K ₁ ÷ K ₄ ) inscribed in a circle of radius R ₁ (the generator can be represented by another plane figure, for example, a parabola). The length l _{1 of the} planes K _n , the angle of inclination β ₁ -β _n , the number n of planes of the screening surface 12 and, accordingly, the radius R _{1 of the} forming circle are determined by the requirements of the screening technology of solid materials. It was experimentally established that for the separation of lump fractions of classes - 100 + 0 mm, the inclination angle β _{1 of the} plane K _{1 of the} discharge zone of the vibrating screens is a multiple of 5 ^o and is equal to β ₁ = (1-3) × 5 ^° . The inclination angle β _{n of} each subsequent plane K _n to the discharge zone of the screen is β _n = β _n-1 + β ₀ , where β ₀ are integers from 2 to 10 ^o . The length L _{1 of the} screening surface 12 along the arc BB is L ₁ = nxl, where l ₁ is the length of the plane K _t . The length l ₁ corresponds to the length of each plane, for example, a regular polyhedron inscribed in a circle of radius R ₁ and is equal to

As a rule, to meet the requirements of screening technology, the number n of planes K _{n of the} screening surface 12 of the vibrating screen is n = 2 ÷ 5 (in Fig. 1, the number of planes is n = 4). The resulting angle Θ _{1 of the} inclination of the screening surface 12 of the explosive arc is determined taking into account the requirements of the screening technology.

To separate lump fractions with a particle size of 400 + 100 mm, the sieving surface 12 (Fig. 5) is formed by the method described above, but it is more preferable to fix the K ₅ planes and the K ₆ plane along a CDE arc of a circle of radius R ₂ . The sieving surface 13 is an irregular polyhedron (as shown in FIGS. 1 and 5) inscribed (conditionally) in a circle of radius R ₂ (the CDE arc can be a fragment of a generator of another plane figure, for example, a parabola).

 Vibrating screen works as follows.

колебаний (вибрации), при необходимости производится регулировка рабочего режима. Амплитуда колебаний грохота и угол ϑ₁ направления вектора

колебаний (вибрации) в загрузочной зоне грохота устанавливается в сторону движения материала таким образом, чтобы слой потока твердого материала быстро распределялся по просеивающей поверхности 12 и 13 грохота с уменьшением толщины потока материала. В разгрузочной зоне грохота амплитуда и угол ϑ₂ направления вектора

колебаний устанавливается в сторону, противоположную движению материала таким образом, чтобы уменьшить скорость потока твердого материала и обеспечить условия для эффективного просеивания кусков твердого материала, размер которых соизмерим (или менее) с размером ячеек 15. (Схематично вектор амплитуды

и угол ϑ направления вибраций показаны на фиг.1).Depending on the requirements of the screening technology, the shape and number of screening surfaces of the screen, the angle of inclination β _n and the length of the planes K _{n are} selected by experimental or calculation methods to separate the flow of solid material by size. On the eccentric vibration exciter 9 in the slots 11, the corresponding number of unbalances is set. From the drive of the screen, the rotation of the eccentric vibration exciter 9 is transmitted via the shaft 10. The operating mode of the screen with the specified amplitude and angle ϑ of the vector direction is established

fluctuations (vibration), if necessary, adjust the operating mode. The amplitude of the vibrations of the screen and the angle ϑ _{1 of the} direction of the vector

vibrations (vibrations) in the loading zone of the screen is set in the direction of movement of the material so that the layer of solid material flow is quickly distributed along the screening surface 12 and 13 of the screen with a decrease in the thickness of the material stream. In the discharge zone of the screen, the amplitude and angle ϑ _{2 of the} vector direction

oscillations is set in the direction opposite to the movement of the material in such a way as to reduce the flow rate of solid material and to provide conditions for the effective sieving of pieces of solid material, the size of which is comparable (or less) with the size of the cells 15. (Schematically, the amplitude vector

and the angle ϑ of the direction of vibration shown in figure 1).

After entering the operating mode of screening, lumpy solid material is fed into the screening device 2, while the loading device allows you to evenly distribute the flow of solid material throughout the screening surface of the screening zone 13 or 12, when one screening surface of the vibrating screen is formed. For the variant with two (or more) screening surfaces, the bulk material was directed to the loading plane K _{6 of the} screening surface 13 with an inclination angle β ₆ . Due to the fact that the loading plane K ₆ has an inclination angle β ₆ > β ₅ (taking into account the direction of the screen vibration vector), the solid material moves along the working planes of the screening surface with a speed of V ₆ > V ₅ . Moreover, the thickness of the layer of material flow on the plane K ₆ decreases sharply and favorable conditions are provided for the separation of material by size. Pieces of material - the under-screening product of screening, the size of which is less than the mesh size of 15 sections 14 of the planes K ₆ and K _{5 of the} surface 13, are sent to the surface 12, and pieces of material, the size of which is comparable to or larger than the size of the cells 15 - over-the-counter product - is sent for subsequent processing .

The underlayer product of the screening surface 13 is directed to the working plane P of the screening surface 12. The screening dynamics on the surface 12 are similar to the process of separating the flow of solid material on the surface 13. However, in contrast to the above, the process of separating the flow of solid material is that the K ₄ planes K ₃ , K ₂ and K ₁ have a regularly increasing angle to loading or decreasing to unloading angle β _n in accordance with the expression β _n = β _n-1 + β _o . In this case, due to the fact that β ₄ > β ₃ > β ₂ > β ₁ , the material flow velocities on the screening surface 12 uniformly decrease: V ₄ > V ₃ > V ₂ > V ₁ , the thickness of the material layer, taking into account its screening through the cells 15, on each of the planes K ₄ ÷ _{1 of the} surface 12 is uniformly reduced. This provides conditions for increasing the efficiency of screening of pieces of solid material with the release of sub- and over-sieve product of the screening surface 12. Typically, the cells 15 of the screening surface 12 have a shape and size that can provide the final size of the solid material specified by the requirements of the crushing technology. The elastic inserts 17 increase the stiffness of the sections 14 and due to the additional resonating effect of the planes K _n enhance the screening process and the cleaning of the screening surfaces 12 and 13 of the vibration screen.

 The dynamic impact of the housing 1 of the screen is reduced by vibration isolators 4, symmetrically installed in the loading and unloading parts of the screen. The vertical dynamic component of vibration transmitted to the inner frame 3 is significantly reduced by vibration base 5, and the dynamic impact of the dynamic impact on the flow of solid material of the screen body 1 is provided by hydraulic shock absorbers 7. The horizontal dynamic component of vibration that occurs during the screening (separation) of the flow of solid material is reduced by the installed elastic shock absorbers 8 between the inner 3 and outer 6 frames of the vibrating screen.

 The proposed technical solution allows to increase the efficiency of the separation of the flow of highly abrasive lumpy solid material, increase the performance of the screen and reduce the dynamic effect on the foundation - the base of the screen.

Claims (5)

1. A vibrating screen comprising a frame, a housing in the form of a box mounted on the frame by means of vibration isolators, with at least one screening surface placed in it in the form of a fragment of the side surface of a polyhedron of two or more rectangular sections arranged along a broken line conditionally inscribed in arc generatrix with an angle of inclination unloading section 5 and fold angles subsequent sections β _n = β _n-1 + β _0, where β ₀ is an integer in degrees exciter, characterized in that the sieving surface is of elastic material in the form of regular or irregular polyhedron, the length l of each section is made equal to

where R is the radius of the arc forming a sieving surface, m;
n is the number of sections of the screening surface,
moreover, the angle of the discharge section β ₁ = (1-3) × 5 ^° , and β ₀ varies from 2 to 10 ^o .  2. Vibrating screen according to claim 1, characterized in that the screen is made of several screening surfaces mounted on top of each other.  3. Vibrating screen according to claim 1, characterized in that the rectangular sections are reinforced with elastic inserts and made of rubber or polyurethane with square, round or rectangular cells.  4. Vibrating screen according to claim 1, characterized in that hydraulic shock absorbers are installed on the frame, at least from the side of the loading zone.  5. Vibrating screen according to claim 1, characterized in that the oscillation (vibration) vector of the screening surface in the loading zone is directed towards the movement of solid material, and in the opposite direction in the discharge zone.

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