RU2405633C1 - Multi-sieve vibration screen - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to loose material sorting equipment, namely to multi-sieve vibration screens, and can be used for separation of loose materials into two, three and more fractions. Proposed screen comprises box articulated with vibration drive and supporting detachable screens arranged one above the other. Said screens comprise frame with sifting surface, loading and unloading appliances secured on the frame above all screens except for bottom one, rigid flat L-like chutes inclined toward the side opposite the carried material direction. It is possible to reload mesh minus on screen arranged below. Chute inclination angle exceeds the angle of friction of carried material on chutes surfaces. Each chute has normally oriented screens and adjoining section with its height not smaller than screen mesh. Sections of flexible tapes are suspended on crosswise beams secured on screen box to overlap screen width and to locate tape lower edges at the screen top surface level. Flexible tapes can be continuous or separate bands that stay in contact by their vertical edges.

EFFECT: higher efficiency and quality.

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Description

The invention relates to equipment for sorting bulk materials, namely to multi-sieve vibrating screens, and can be used in crushing and screening and processing plants for the separation of bulk materials into two, three or more fractions.

A multi-sieve vibrating screen is known, containing a box kinematically connected with a vibrodrive with removable screens fixed on it, including a frame with a screening surface, loading and unloading devices (Vaysberg L.A., Kartavyi A.I., Korovnikov A.N. Screening surfaces of screens. St. Petersburg, VSEGEI, pp. 17-18, Fig. 1.3a, 2005).

However, when sorting bulk cargoes containing an increased number of small fractions, the sieving surfaces of the sieves located under the top screen of the vibrating screen, as well as the top screen are not used effectively, therefore, to separate such bulk cargo into separate fractions with a given screening efficiency, it is necessary to choose a screen with an increased area screening surface with corresponding increased sizes of the screens themselves.

A multi-sieve vibrating screen adopted for the prototype is known, comprising a box kinematically connected to the vibrodrive with removable sieves fixed thereon, including a frame with a screening surface, loading and unloading devices mounted on frames under all sieves, except the lower one, rigid flat gutters Г- a cross-sectional profile inclined in the direction opposite to the direction of movement of the sorted material, with the possibility of overloading the under-sieve product to the lower e sieve (WO 2007069970 A1, 21.06.2007, V07V 1/46).

However, the known design of the screen does not fully utilize the design capabilities, which limits the efficiency of screening bulk materials with their separation into several fractions.

The technical result of the invention is to increase the efficiency of screening and screening productivity due to the return of the under-sieve products of the sorted material towards the loading device of the screen, as well as by limiting the speed of movement of the sorted material in the upper sieve.

The technical result is achieved by the fact that in a multi-sieve vibrating screen containing a box kinematically connected to the vibrodrive with removable screens fixed to it under each other, including a frame with a screening surface, loading and unloading devices fixed to the frames under all but the bottom, rigid flat troughs L-shaped profile in cross section, inclined to the side opposite to the direction of movement of the sorted material, with the possibility of overloading the under-sieve product to the bottom laid sieve, the angle of inclination of the gutters to the horizontal is greater than the angle of friction of the material being sorted on their surface, each gutter is made with a section normally adjacent to the sieve plane and adjacent to it, the height of which is assumed to be not less than the size of the sieve mesh, while above the upper sieve on the transverse beams , mounted on the screen box, suspended segments of flexible tapes overlapping the sieve along its width, and with the placement of the lower edge of the segments of tapes at the level of the upper surface of the sieve, moreover, the flexible tapes are made continuous or in Idea of individual strips in contact with each other with their vertical edges.

Figure 1 shows the roar, side view, figure 2 is a section aa in figure 1 with continuous flexible tapes above the upper sieve, figure 3 is the same when performing flexible tapes from separate strips.

A multi-screen vibrating screen contains kinematically connected to a vibrating actuator (not shown) box 1 with removable screens mounted on it under each other. Each sieve includes a frame 2 with a screening surface 3. The screen is equipped with loading 4 and unloading 5 devices. Under all sieves, except the lower one, rigid flat gutters 6 are fixed on their frames 2, inclined to the side opposite to the direction of movement 7 of the sorted material with the possibility of overloading the under-sieve product on the sieve below. Moreover, the angle α of the inclination of the grooves 6 to the horizon is taken to be greater than the friction angle of the sorted material about their surface. Each trough 6 is made of an L-shaped profile in cross section with a section 8 normally oriented to the sieve plane and adjacent to it, whose height h is assumed to be no less than the size of the sieve mesh. Over the upper sieve on the transverse beams 9, mounted on the box 1 of the screen, suspended segments of flexible tapes 10, overlapping the sieve in its width and with the placement of the lower edge of the segments of the tapes 10 at the level of the upper surface of the sieve. Flexible tape 10 can be made solid (see figure 2) or in the form of individual strips in contact with each other with their vertical edges 11 (see figure 3). 12 - sortable material.

The roar operates as follows. The material to be sorted through the loading device 4 is fed to the upper sieve, along which it moves in direction 7 under the action of directed vibrations of the box 1. Due to the interaction of particles of the sorted material 12 with segments of flexible bands 10, which deviate in the direction of movement 7 of the sorted material 12, there is a limitation of the speed of its movement and an increase in the efficiency of screening of the material on the upper sieve. In the process of moving through the sieve of the material fraction, smaller mesh sizes are loaded onto the downstream sieve, on which the process of separation of even smaller fractions takes place. At the same time, a part of the under-sieve product, the amount of which depends on the number of grooves 6 sequentially installed on the upper sieve one after the other, returns to the side of the loading device 4, i.e. in the direction opposite to the direction of 7 movement of the material in the upper sieve. Due to this, the screening time of the material on the downstream sieve is increased, which helps to increase the efficiency of screening and allows to increase the performance of the screen with the same sieve sizes and the area of the screening surface. Similarly, screening of the material occurs on the next sieve. The design of the gutters 6 of the L-shaped profile in cross section eliminates the possibility of jamming of the particles of the under-sieve product when it is unloaded from the sieves, and also provides the necessary rigidity of the gutters 6.

Distinctive features of the invention provide an increase in screening efficiency and screening productivity due to the multiple return of the under-sieve product of the sorted material on each sieve below the screen loading device and limiting the speed of advancement of the sorted material in the upper sieve.

Claims (1)

A multi-screen vibrating screen containing a box kinematically connected with a vibrating drive with removable screens fixed to it under each other, including a frame with a screening surface, loading and unloading devices mounted on frames under all screens, except the lower one, rigid flat G-shaped grooves in the transverse cross-sections inclined in the direction opposite to the direction of movement of the sorted material, with the possibility of overloading the sieve product on a lower sieve, characterized in that the goal of the tilt of the gutters to the horizon is taken to be greater than the angle of friction of the material being sorted on their surface, each gutter is made with a section normally adjacent to the sieve plane and adjacent to it, whose height is assumed to be no less than the size of the sieve mesh, while above the upper sieve on the transverse beams fixed to the screening box, suspended sections of flexible tapes overlapping the sieve along its width and with the placement of the lower edge of the sections of tapes at the level of the upper surface of the sieve, and the flexible tapes are made solid or in the form of separate floors wasps in contact with each other with their vertical edges.

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