RU2463112C1 - Hydraulic separator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to grading particles to settling velocity, density, geometrical sizes, and may be used in mining, construction and chemical industry, etc. Proposed separator comprises cylindrical housing made up of two aligned cylinders with their bottom edges connected with separation products receivers to make housing bottom. Said housing accommodates rotary separation chambers with pairs of "П"-shape guide plates with bases directed upward and radial plates made up of two aligned cylindrical shells to make communicating vessel with said housing. It comprises shield made up of separate detachable segments of ring displacing radially, driven shaft, initial material feeder, and separation products receivers. Device to stabilise water level in separation chambers comprises branch pipe to feed and discharge water arranged over outer cylinder height from its top edge to radial plate bottom element top edge. Sections of narrow channels made up of crossing plates are arranged between cylindrical shells and pairs of "П"-shape guides. Base of every separation products receiver accommodates inclined cylinder housing rotary shaft with screw fitted thereon, parallel with cylinder bottom.

EFFECT: higher efficiency of separation.

2 cl, 3 dwg

Description

The invention relates to a device for separating particles by hydraulic size, density, geometric dimensions and can be used in mining, construction, chemical and other industries.

Known hydraulic classifier of granular materials (ed. Certificate. No. 1738358, IPC B03B 5/62, bulletin No. 21.92). The hydraulic classifier contains a cylindrical body with a bottom, made in the form of a truncated cone installed with a smaller base upwards, in the lower part of which there are mounted nozzles - receivers for separation products. Inside the cylindrical body is a cylindrical shell connected to the drive shaft. On the outer side of the shell, radial plates are installed with a gap to the body and the bottom, which together with the shell form rotating dividing chambers in the body, above which the source material feeder is mounted. The disadvantages of the known hydraulic classifier of granular materials that reduce the efficiency of separation of particles by size include:

- the height of the liquid in the separation chambers in the radial direction, limited by the surface of the truncated cone, is different, and therefore, the deposition time of particles of the same hydraulic size is different;

- the time of deposition of particles in the liquid and plus the time of their sliding on the surface of the conical bottom in areas of unequal length from the point of incidence to this surface to the holes leading to the receiving nozzles even more differs, even for particles of the same shape (with one coefficient of friction);

- a layer of separated material formed on the surface of the cone with a height equal to the gap between the separation plates and the specified surface will periodically, as it accumulates, drain into various receivers of separation products.

The closest in technical essence is a hydraulic separator (RF patent No. 2395345, IPC B03B 5/62, 2010) for separating particles by size, containing a cylindrical body with a bottom, mounted inside the body, with a gap to it and the bottom with the possibility of rotation, separation chambers with radial plates, a screen in the gap between the separation chambers and receivers of the separation products, a shaft with a rotation drive, a source material feeder and separation products receivers. The body is made in the form of two coaxial cylinders, the lower edges of which are hermetically connected to the receivers of the separation products, forming the bottom of the body, and the separation chambers are made in the form of two coaxial cylindrical shells connected by pairs of U-shaped guides with the base up, which form a communicating vessel. The housing is equipped with a device for regulating the level of the separation zone - an external pocket with nozzles for draining and supplying water.

The main disadvantages of the known separator are:

- mutual clogging of separation products due to deviation of particle deposition trajectories (especially particles of a flattened shape) from the axis of symmetry of their flow in the zone between the cylinders of the separation chamber and the radial partitions;

- low efficiency of enrichment of particles by density due to their separation solely by deposition rates (by hydraulic fineness), which is a significant drawback when separating particles of wide ranges of fineness;

- instability of the level of the separation medium in the separator due to the low-efficiency system for unloading separation products.

The deviation from the straight-line deposition of particles in the separation zone occurs due to the hydrodynamic features of their flow around the medium, which, in turn, take on a particularly complex character with the irregular shape of the separated grains. So, a polymineral mixture of one size range (according to the results of a sieve analysis) due to the flattened shape of particles of higher density (for example, particles of native gold) is not effectively separated. Therefore, to optimize the separation process, it is necessary to limit the possibility of deviation of particles from the axis of symmetry of the flow by creating a mechanical barrier in the horizontal plane in the form of continuous vertical walls.

In the presence of equidistant particles, i.e. particles precipitating with the same final speed, but with different densities, gravitational enrichment by the method of hydraulic classification becomes difficult. Therefore, to increase the separation efficiency, it is necessary to combine the mechanism of separation of particles according to deposition rates and the mechanism of differential acceleration (i.e. separation according to particle density) implemented, for example, in jigging machines. Artificially changing the deposition rate of particles can be achieved by changing the surrounding deposition conditions. So, with a sharp change in the conditions for the deposition of particles in an "unlimited medium" on the conditions of "near-wall deposition", the particles will slow down and the more, the lower their density. Further, after the particles pass through narrow channels (the “near-wall deposition” zone), the motion conditions change to the initial ones, i.e. become again in a “conditionally unlimited environment” with no side obstacles. Thus, alternating in the separation chamber along its height (depth) narrow channels and zones of particle deposition in a “conditionally unlimited medium”, a separation mechanism for their differential acceleration is realized.

The material is unloaded in known separator designs through cranes, i.e. "By gravity", which with an insufficient amount of material (sediment) in the receiver leads to an uncontrolled output of the liquid medium and a significant decrease in its level in the separator. In addition, unloading a sufficiently large material (more than 1-2 mm) by gravity is difficult to organize. During autonomous operation of the system for regulating the level of the separation zone, in case of unintentional discharge (spill) of water from unloading devices, the separator is quickly filled with water through the nozzle to supply it, which leads to the formation of mixing flows that impede the effective separation of particles. Therefore, to stabilize the separation process, it is necessary to provide for the possibility of unloading the separation product with a constant moisture content (ratio W: T). The unloading of settled material from the receivers can be carried out mechanically, for example by lifting the sediment along an inclined trough above the pulp level with a rotating spiral.

The aim of the invention is to increase the efficiency and stability of the process of separation of particles by density. This is achieved by the fact that

1) sections of narrow channels are installed in the gap between the cylinders and the radial partitions of the separation chamber at a distance from each other along its height (depth), for example, three, consisting of intersecting vertical plates, which form a zone of wall deposition along the path of the particles,

2) the receivers of the separation products are equipped with a device for the mechanical transportation of sludge above the level of the pulp and its discharge - an inclined cylinder, in which a rotating shaft with a spiral (screw) mounted on it is placed parallel to its bottom.

In Fig.1 shows a hydraulic separator (General view), Fig.2 is a section along aa, Fig.3 shows the location of the plates forming three sections of vertical channels at different depths of the separation chamber.

The hydraulic separator comprises a cylindrical body formed by the outer 1 and inner 2 cylinders, to the lower edge of which are attached the receivers of separation products 3 with an inclined cylinder 4, in which a rotating shaft 5 with a spiral 6 mounted on it is placed parallel to its bottom to unload them. A separating chamber 7 is made coaxially with cylinders 1 and 2 with gaps to them and receivers of separation products inside the case, made of two coaxial, cylindrical shells forming a communicating vessel with the case, connected by pairs of U-shaped radial partitions with the base up 8. In the gap between partitions are installed plates 9 made of separate rectangular elements (for example, three) with the possibility of vertical movement and dismantling. The separation chamber by means of a traverse 10 is connected to the shaft 11 and is driven by an electric motor 12. The separator is equipped with a source material feeder 13 mounted above the separation chamber and a device for adjusting the level of the separation zone 14, installed along the height of the outer cylinder from its upper edge to the level corresponding to the installation one element of the radial plates. The device is made in the form of an external pocket with nozzles for draining and supplying water. In the gap between the separation chamber and the receivers of the separation products, screen plates 15 are installed in the form of segments of a circular ring with the possibility of their radial movement and removal. In the separation chamber at various depths, sections of narrow channels 16 are installed (for example, three sections), made in the form of intersecting vertical plates that form zones of wall deposition.

The separator works as follows. In the enrichment mode of a material containing particles of different densities and previously dispersed into fairly narrow particle size classes, plates of the screen 15 are installed in such a way as to prevent the distribution of particles across all receivers of separation products and to ensure unloading only from certain receivers. At a given height of the separator working zone, depending on the size of the material in the feed, elements of radial plates 9 and sections of narrow channels 16 are installed. The housing formed by the external 1 and internal 2 cylinders with receivers of separation products 3 and the separation chamber 7 installed in it are filled with water appropriate level of the working area of the separator. The camera through the shaft 11 and the motor 12, connected by a traverse 10, is driven into rotation. The shaft 5 and the spiral 6 are rotated by an electric motor 17 of each receiver of separation products. The feed material 13 is fed into the chamber by the feeder 13 in dry form or in the form of liquid pulp. Particles of the material under the influence of gravitational, Archimedean and water resistance forces acquire a different deposition rate and depending on it, as well as the height and speed of rotation of the chamber are distributed among the receivers and plates of the screen. Due to the successively established sections of narrow channels in the separation zone, differential acceleration of particles is realized during the deposition process, therefore, material particles are distributed among the receivers in accordance with their density. Denser particles (particles with greater inertia) acquire greater acceleration upon a sharp transition from the zone of near-wall deposition to the zone of conditionally free deposition, therefore, they precipitate and concentrate faster in the zone of a valuable product (concentrate). Further, during a sharp transition from the zone of conditionally free deposition to the zone of near-wall deposition, particles of relatively higher density slow down less intensely, which is also part of the separation mechanism of differential acceleration. In the direction of the movement of the chambers, the material accumulated on the screen plates is mechanically transported through the bottom of the radial plates to the respective receivers of the enrichment products. Unloading products from the receivers is due to the rotation of the spirals. In the hydraulic classification mode of the material to obtain narrow particle size classes, the plates of the screen 15 are not installed, and the products are unloaded from all receivers.

Optimization of the process of separation of the source material is carried out by changing the speed of rotation of the separation chamber, the level of the separation zone, as well as the height of the sections of narrow channels (differential acceleration zones), the length of the zone of conditionally free deposition (the distance between two consecutive sections of narrow channels), the number of sections along the particle deposition path and channel size.

The high efficiency of separation of particles by their size or density is achieved by the fact that the apparatus virtually eliminates the mixing conditions of these particles and implements a combination of separation mechanisms: separation by deposition rate and differential particle acceleration.

Claims (2)

1. A hydraulic separator, including a cylindrical body, made in the form of two coaxial cylinders, the lower edges of which are hermetically connected to the receivers of the separation products, forming the bottom of the body, separation chambers installed inside the body with a gap to it and the bottom rotatably, with pairs of guides П- shaped base up and radial plates, made in the form of two coaxial cylindrical shells, which form a communicating vessel with the body, a screen made in the form of separate segments a circular ring with the possibility of their radial movement and removal, a shaft with a rotation drive, a source material feeder, separation product receivers, a device for stabilizing the water level in the separation chambers - a pipe for draining and supplying water, installed along the height of the outer cylinder from its upper edge to the level the upper edge of the lower element of the radial plates, characterized in that between the cylindrical shells and pairs of U-shaped guides installed sections of narrow channels made of vertical intersections Washable plates. 2. The hydraulic separator according to claim 1, characterized in that at the base of each receiver of separation products there is an inclined cylinder in which a rotating shaft with a spiral (screw) mounted on it is placed parallel to its bottom.

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