WO2019178653A1 - Hydrocyclone for a comminution circuit - Google Patents

Abstract

The invention can be used in the classification of particles of suspensions having a high dry solids content. A hydrocyclone comprises a cylindrical inlet section (3) having a tangential feed pipe (2) and a coaxial overflow pipe (4), and a conical body (15). A water box (6) comprises an outer wall (26), and an inner cylindrical porous wall (11) made of sintered corundum. In the inner cavity of the water box (6) and the conical body (15) there is disposed an overflow nozzle (16) consisting of a cylindrical portion (17), tightly inserted into the overflow pipe (4), and a conical portion (27). The conical portion consists of two 180° vanes (24, 25). Said vanes are disposed at an identical distance from an axis of symmetry and form wells (18, 19), the openings of which are oriented counter to the direction of rotation of a slurry. The taper angle of the nozzle (16) is equal to the taper angle of the conical body (15). The invention provides more efficient particle separation by reducing eddy formation that leads to the exchange of solid particles between a descending peripheral flow and an ascending axial flow.

Description

 HYDROCYCLONE FOR GRINDING CHAIN

OVERALL TECHNICS

The invention relates to the field of mineral processing and more specifically to a device for classification, where a higher efficiency of the separation process is required when working with suspensions with a high solids content.

BACKGROUND OF THE INVENTION

Known hydrocyclone [1] with improved removal of fine material from sand, including: the zone of tangential injection of the supplied pulp; a separation zone following the discharge zone, with a nozzle for unloading the sands and a nozzle located axially in the inner cavity of the hydrocyclone for the upper product; at least one other inlet in the discharge zone for supplying the barrier fluid; a thin plate in the discharge zone that separates the path of the injected pulp from the path of the barrier fluid, while it mixes with the pulp in the separation zone, where the separation zone includes a conical part adjacent to the cylindrical part, which leads to the nozzle for unloading sand.

The disadvantage of this solution is that it does not avoid a swirl between the descending peripheral and ascending axial flows, which leads to the exchange of solid particles between them and to a decrease in the separation efficiency.

SUMMARY OF THE INVENTION

The objective of the invention is the creation of a hydrocyclope for the grinding chain, through which to eliminate these disadvantages.

 The problem was solved by a hydrocyclone, which includes a tangential injection zone of the feed pulp, a separation zone following the discharge zone, with a nozzle for unloading sand and a nozzle located axially in the inner cavity of the hydrocyclone for the top product.

The hydrocyclone consists of a cylindrical inlet section to which a supply pipe is tangentially mounted and an overflow pipe is axially mounted. Cylindrical inlet section · attached to the water chamber by means of a flange to it top cover. The water chamber consists of an inner wall and an outer wall attached by thread to the lid. The inner wall of the water chamber is a cylindrical porous wall made of sintered corundum.

The inner wall of the water chamber is sealed at the top and bottom with rubber seals. A flange is mounted in the lower part of the water chamber, which is attached from below to the flange of the conical body of the hydrocyclone. In the lower part of the conical body one lower flange is mounted, which is attached to the flange of the sand nozzle. A ceramic insert with high abrasion resistance is preferably placed in the sand nozzle.

In the inner cavity of the water chamber and the hydrocyclone body, there is a nozzle for the upper product, which consists of a cylindrical part tightly inserted into the overflow pipe of the feed section and a conical part, which consists of two 180 ° wings located opposite the cone forming and forming wells whose holes are directed against the direction of rotation of the pulp. The cone angle of the overflow nozzle is equal to the cone angle of the hydrocyclone body. The conical part of the overflow nozzle is closed by the top cover and the bottom cover.

DESCRIPTION OF THE FIGURES

Figure 1 depicts a vertical section of a hydrocyclone.

 Figure 2 is a cross section of the plane aa of the hydrocyclone.

MODES FOR CARRYING OUT THE INVENTION An example embodiment of the invention is shown in the figures.

The hydrocyclone consists of a cylindrical inlet section 3 with a flange 5. An inlet pipe 2 is mounted tangentially to the inlet section 3. An overflow pipe 4 is mounted axially to the inlet section 3, the cover 7 of the water chamber 6 is bolted 28, 29 with nuts 30, 31 to the flange 5 entrance section .3. The water chamber 6 consists of an external cylindrical wall 26, which is mounted with a thread 9 to the cover 7. Under the outer cylindrical wall 26 there is a lower flange 13 of the water chamber 6. A cylindrical porous wall C sealed with rubber seals 10 is mounted in the inner cavity of the water chamber 6 12. Wall 11 is made of sintered corundum, or of ceramic with increased hardness and wear resistance.

Wadiadno; the outer wall 26 of the water chamber 6 is attached to the supply pipe 8. From the bottom the sides of the water chamber 6 by means of a flange 13 and a flange 14, respectively, with bolts 32,

33 and nuts 34, 35, the conical body 15 of the hydrocyclone is fastened. The inner surface of the conical housing 15 is lined with a wear-resistant coating such as basalt or polyurethane.

In the lower part of the housing 15, a connecting flange 21 is mounted, which is fastened with bolts 36, 37 with nuts 38, 39, respectively, to the flange 22 of the sand nozzle 23. A ceramic insert 40 with high abrasion resistance is preferably placed in the sand nozzle 23. In the inner cavity of the water chamber 6 and the housing

15 placed the nozzle for the upper product 16, consisting of a cylindrical part (tail)

17 and the conical part (working compartment) 27. The cylindrical part 17 is tightly inserted into the overflow pipe 4 so as to prevent rotation under the pressure of the tangential force applied by the swirl flow. The conical part 27 is closed at the top and bottom, respectively, by the upper cover 1 and the lower cover 20. The conical part 27 consists of two 180 ° wings 24, 25 located at the same distance from the axis of symmetry and forming wells 18, 19, whose holes are directed against the direction pulp rotation. The angle of the cone 27 of the nozzle 16 is equal to the angle of the housing 15 of the hydrocyclone.

APPLICATION (USE) OF THE INVENTION

The hydrocyclone works as follows. The pulp of the mill is introduced tangentially into the hydrocyclone through the pipe 2 under pressure by means of a slurry pump and swirls in the inlet section 3. In addition to the rotational movement of the vortex, it moves up and down. Entering the zone of the water chamber 6, the swirl slides along the length of the porous wall 11, through which, water is introduced perpendicular to the direction of movement. Due to its lower specific gravity, water creates a centripetal force and carries small particles to the axis of the hydrocyclone. The magnitude of this force depends on the amount of water supplied and is determined by regulating the pressure in the water chamber 6. Under the water chamber 6, a coarse-grained pulp fraction, already washed from the sludge, goes down the conical body 15 of the hydrocyclone and is discharged through the tabs 40 of the sand nozzle 23. The fine fraction located in the core of the hydrocyclone enters through the bore holes 18, 19 of the overflow nozzle 16, swirls in it and exits through the cylindrical part 17 to unload through the overflow pipe 4. To a large extent, the diameter D ₅₀ (diameter tr particles that fall into the coarse-grained and fine-grained fractions with the same probability) of the separation process depends on the width of the wells 18, 19, the pulp pressure, the flow rate and its grain size in the feed, the pressure in the water chamber 6, and the opening diameter of the sand 40 tab nozzles 23 and hydrocyclone geometry. Important, however, less powerful factors are the angle of the cone, · —the relationship between the heights the inlet section 3, the water chamber 6 and the conical part 15; the location of the overflow nozzle 16 and others. After washing in the zone of the water chamber 6, the swirling suspension passes into the separation zone, in which the overflow enters the wells 18, 19 and due to the lower pressure in the plane of the hole of the cylindrical part 17, an upward force is created. Thus, the fine-grained fraction leaves through the overflow pipe 4. The separation process is improved due to two reasons: 1) the creation of a centripetal force by supplying water through the porous wall 11, which is able to entrain small particles to the core and 2) turbulence is avoided due to the fact that during peripheral flow movement down There is no physical contact with the flow moving up the axis. So, due to the increased efficiency, the finished class does not return to the mill together with the circulating load, which affects positively its productivity.

Claims

CLAIM 1. The hydrocyclone for the grinding chain, which includes a tangential injection zone of the feed pulp, a size separation zone following the discharge zone, with a nozzle for unloading the sands and a nozzle located axially in the inner cavity of the hydrocyclone for unloading a fine-grained product, characterized in that it consists of a cylindrical inlet section (3), to which the incoming supply pipe (2) is tangentially mounted and an overflow pipe (4) is axially mounted; the cover (7) of the water chamber (6) is fastened to the flange (5) of the inlet section (3) with bolts (28), (29) and nuts (30), (31); the water chamber (6) consists of an external wall (26), which is attached with a thread (9) to the cover (7); the inner wall (11) of the water chamber (6) is a cylindrical porous wall (11) made of sintered corundum, sealed at the top and bottom with rubber seals (10, 12); in the lower part of the water chamber (6) there is a flange (13), which is attached to the flange (14) of the conical body (15), in the lower part of which a flange (21) is mounted, attached to the flange (22) of the sand nozzle (23); moreover, a ceramic insert (40) with high resistance to abrasion is preferably placed in the sand nozzle (23); in the inner cavity of the water chamber (6) and the housing (15) there is a nozzle for the upper product (16), which consists of a cylindrical part (17) tightly inserted into the overflow pipe (4), and a conical part (27), which consists of two 180 ° wings (24, 25) located at the same distance from the axis of symmetry, forming wells (18, 19), whose holes are directed against the direction of rotation of the pulp; the angle of the cone of the nozzle (16) is equal to the angle of the conical body (15), and the conical part of the nozzle (16) is closed by the upper cover (1) and the lower cover (20). 2. Hydrocyclone according to patent claim 1, characterized in that the inner wall (11) of the water chamber (6) is made of ceramic with increased hardness and wear resistance.