CN219943247U

CN219943247U - Countercurrent classifier

Info

Publication number: CN219943247U
Application number: CN202320951356.8U
Authority: CN
Inventors: 付思特
Original assignee: Baizhong Environmental Technology Shanghai Co ltd
Current assignee: Baizhong Environmental Technology Shanghai Co ltd
Priority date: 2023-04-25
Filing date: 2023-04-25
Publication date: 2023-11-03
Anticipated expiration: 2033-04-25

Abstract

The utility model discloses a countercurrent classifier which comprises an upper part, a middle part and a lower part which are connected with each other in sequence, wherein the upper end part of the upper part is provided with a solid feeding pipe, the lower part is provided with a water inlet pipe for countercurrent water, and the bottom end of the lower part is provided with a solid particle discharge pipe; wherein the upper part and the lower part are rectangular bodies, the length of the upper part is larger than that of the lower part, the cross section of the middle part is rectangular, and the area of the middle part linearly increases from bottom to top; an overflow channel is provided along the upper long side; the water inlet pipes are arranged in parallel, and are connected with a plurality of nozzles; the classifier has a linear increase in cross section, which improves countercurrent distribution over the entire extended cross section, reduces short flow of particle suspension, and thus improves separation efficiency. The optimized distribution of countercurrent flow coupled with the linear increase in cross-sectional area increases hydraulic efficiency and reduces short flow through the classifier.

Description

Countercurrent classifier

Technical Field

The utility model relates to a particle suspended matter separation device, in particular to a countercurrent classifier.

Background

Mining (mining) the particulate mixture of the environmental and resource recovery industries typically requires separation based on particulate size or density differences. Classification or sorting is often performed in suspension, wherein the particles settle under gravity while maintaining a fluid flow opposite to the settling direction of the particles. The purpose of a countercurrent classifier is to separate a mixture of particles in suspension based on differences in physical properties, i.e. particle size and density. These particles exhibit different sedimentation rates. The control of the countercurrent flow causes smaller or lighter particles to be flushed up while the denser or larger diameter particles move downward.

The usual countercurrent classifier tank has a bottom cylinder followed by a middle conical section and a top larger cylinder. The tapered structure means that its horizontal cross-sectional area increases from bottom to top. This allows a higher turbulence in the lower part for washing, while the turbulence in the upper part is smaller, to avoid large or heavy parts being washed away. The overflow weir is arranged on the circumference direction of the classifier, and countercurrent fluid rising in the center of the tank can flow to the circumference for diffusion and discharge.

The cylindrical design of the prior art classifiers means that the increase in cross-sectional area is the square of the diameter, and for a linear increase in diameter of a conventional tank, the cross-sectional area increases in square numbers, which results in a non-linear decrease in countercurrent velocity, with low hydraulic efficiency. The cylindrical design of the tank means that the ratio of the length to the cross-sectional area of the weir along the circumference is small, while the maximum horizontal flow distance of the fluid to the weir is long. To avoid that the overload of the weir results in a low separation efficiency, the maximum size of the tank is limited. Another disadvantage is that circular weirs are difficult to level. A small liquid level difference in the range of a few millimeters can lead to significant unbalanced flow and reduce overall efficiency. The counter-flow fluid is generally injected uniformly over the cross-section of the lower part of the vessel, and during the rising of the fluid, most of the fluid will remain in the centre of the vessel due to inertial forces and disproportionate area increases, uneven flow velocity distribution resulting in external short-circuit flow.

Disclosure of Invention

The utility model aims to: the object of the present utility model is to provide a countercurrent classifier for reducing short flows of settled suspension and improving overall efficiency.

The technical scheme is as follows: the utility model relates to a countercurrent classifier which comprises an upper part, a middle part and a lower part which are connected and communicated with each other in sequence, wherein the end part of the upper part is provided with a solid feeding pipe, the lower part is provided with a water inlet pipe for countercurrent water, and the bottom end of the lower part is provided with a solid particle discharge pipe; the upper part and the lower part are rectangular, the length of the upper part is larger than that of the lower part, the cross section of the middle part is rectangular, and the area of the middle part linearly increases from bottom to top; an overflow channel is provided along the upper long side; the water inlet pipe is provided with a plurality of water inlet pipes in parallel, and a plurality of nozzles are connected to the water inlet pipe.

Further, the side wall of the middle side wall in the vertical direction is arc-shaped, the angle range of the arc-shaped wall surface is 40-50 degrees, and the bottom end of the arc-shaped wall surface is tangent with the side wall of the lower part; the high flux near the curved wall increases the average flow velocity, thereby increasing the coanda effect.

Further, the ratio of the curved surface radius of the middle arc-shaped wall surface to the difference value between the upper long side and the lower long side is 1.25-6.5.

Further, the end part of the overflow channel is provided with an overflow pipe, and the length-width ratio of the upper part is 5-10; to avoid uneven load rates due to the coanda effect.

Further, the ratio of the upper length to the lower length is in the range of 1.5-3; the higher perimeter to cross-sectional area ratio allows for the installation of a larger overall length overflow channel, eliminating the prior art size limitations of the classifier.

Further, the height difference between the bottom end of the upper part and the lower part is h, and half of the length difference between the upper part and the lower part is x, h: x ranges from 2 to 5.

Further, the distance between the nozzles is reduced linearly from the central axis to the outside in sequence, and the ratio of the minimum distance between the nozzles to the maximum distance is equal to the ratio of the lengths of the upper part and the lower part; the increase in nominal countercurrent flux can be achieved by changing the distance between evenly distributed nozzles or by changing the size of the nozzles with the nozzle distance unchanged, the flow of countercurrent fluid increases linearly from the classifier center to the short outer sidewall, the coanda effect is enhanced, the push flow pattern at the center of the classifier is avoided, and the flow distribution from the small cross-sectional area at the lower part to the large cross-sectional area at the upper part is improved, respectively.

Further, a material conveying pipe is arranged above the upper part, and the material feeding pipe is communicated with the material conveying pipe.

Further, the lower part is provided with a counter-flow water delivery pipe, and the water inlet pipe is communicated with the water delivery pipe.

Further, the upper part is provided with an automatic control valve and its end is connected with a drain pipe.

Working principle: introducing the particulate mixture into the body through a solids feed tube and moving downwardly under the force of gravity; simultaneously, fluid is provided for the countercurrent water inlet pipe, and is sprayed into the body through the nozzle; the fluid and the particle mixture move in opposite directions, and different sedimentation speeds are shown due to different characteristics of the particles, wherein smaller or lighter particles are driven by the fluid to reverse the movement direction and sequentially discharged outwards through the overflow channel and the overflow discharge pipe, and larger or heavier particles always keep downwards moving and are discharged outwards through the solid discharge pipe, so that the separation of the particle mixture with different sizes and densities is completed. The suspension is introduced in the centre of the middle section and the countercurrent fluid is injected in the lower section, the countercurrent fluid being distributed along the cross-section of the lower section, the flow increasing linearly from the centre to the short outer wall.

The beneficial effects are that: compared with the prior art, the utility model has the following advantages:

(1) The rectangular geometry allows for longer lengths of particular weirs per surface area compared to circular geometry, thereby reducing the loading rate of the weirs. The maximum width of the classifier is dependent on the maximum cofferdam load rate allowed and the horizontal distance from center to cofferdam, rectangular coverage allows for installation space savings and modular use.

(2) The classifier has a linear increase in cross section, which improves countercurrent distribution over the entire extended cross section, reduces short flow of particle suspension, and thus improves separation efficiency. The optimized distribution of countercurrent flow coupled with the linear increase in cross-sectional area increases hydraulic efficiency and reduces short flow through the classifier.

Drawings

FIG. 1 is a cross-sectional view of a countercurrent classifier of the present utility model;

FIG. 2 is an overall perspective view of the countercurrent classifier of the present utility model;

FIG. 3 is a schematic top view of the lower portion of the countercurrent classifier of the present utility model.

Detailed Description

The technical scheme of the utility model is further described below with reference to the accompanying drawings.

As shown in fig. 1 to 3, a countercurrent classifier is fixedly connected with an upper part 1, a middle part 2 and a lower part 3 from top to bottom in sequence; the upper part 1 and the lower part 3 are cuboid, and the length-width ratio of the upper part 1 is 5-10; the ratio of the length of the upper part 1 to the lower part 3 ranges from 1.5 to 3; the height difference between the bottom end of the upper part 1 and the lower part 3 is h, and one half of the length difference between the upper part 1 and the lower part 3 is x, h: x is 2-5; the cross section area of the middle part 2 grows linearly from bottom to top, specifically, the side walls at two sides of the middle part 2 are arc-shaped, the angle range of the arc-shaped wall surface is 40-50 degrees, and the bottom end is tangent with the side wall of the lower part 3; a plurality of vertical solid feeding pipes 4 are arranged on the upper part 1, and the feeding pipes 4 are communicated with a transverse solid particle conveying pipe 10; three overflow channels 9 are arranged along the long side of the upper part 1, and the ends of the overflow channels 9 are fixedly connected with overflow pipes 7; the bottom end of the lower part 3 is provided with a solid particle discharge pipe 6; an automatic control valve 12 is fixedly arranged above the upper part 1, and the end part of the valve is downwards connected with a discharge pipe 6; the lower part 3 is provided with a plurality of parallel water inlet pipes 5 for countercurrent water, and the end parts of the water inlet pipes 5 are communicated with the same countercurrent water delivery pipe 11; a plurality of nozzles 8 are arranged on the single water inlet pipe 5, or a plurality of rows of nozzles 8 are arranged on the bottom plate of the lower part 3, each row of nozzles 8 is respectively communicated with the water inlet pipe 5, the distance between each row of nozzles 8 is sequentially and linearly reduced outwards from the central axis, and b1< b2< b3...bn-1 < bn; the ratio of the minimum distance to the maximum distance between the nozzles 8 is equal to the ratio of the lengths of the upper part 1 and the lower part 3.

Claims

1. A countercurrent classifier comprises an upper part (1), a middle part (2) and a lower part (3) which are sequentially connected and communicated, wherein a solid feed pipe (4) is arranged at the end part of the upper part (1), a water inlet pipe (5) for countercurrent water is arranged at the lower part (3), and a solid particle discharge pipe (6) is arranged at the bottom end of the lower part (3); the device is characterized in that the upper part (1) and the lower part (3) are rectangular, the length of the upper part (1) is longer than that of the lower part (3), the cross section of the middle part (2) is rectangular, and the area of the middle part is linearly increased from bottom to top; an overflow channel (9) is arranged along the long side of the upper part (1); the water inlet pipe (5) is provided with a plurality of water inlet pipes in parallel, and the water inlet pipe (5) is connected with a plurality of nozzles (8).

2. A counter-current classifier according to claim 1, wherein the side walls of the middle part (2) are arc-shaped in the vertical direction, the angle of the arc-shaped wall surface ranges from 40 ° to 50 °, and the bottom end is tangential to the side walls of the lower part (3).

3. A counter-current classifier according to claim 2, wherein the ratio of the radius of the curved surface of the curved wall of the middle part (2) to the difference between the long sides of the upper part (1) and the lower part (3) is in the range of 1.25-6.5.

4. Countercurrent classifier according to claim 1, characterized in that the overflow channel (9) is provided with overflow pipe (7) at the end, the upper part (1) having an aspect ratio in the range of 5-10.

5. A counter-current classifier according to claim 1, wherein the ratio of the length of the upper part (1) to the length of the lower part (3) is in the range of 1.5-3.

6. A counter-current classifier according to claim 1, wherein the difference in height between the bottom end of the upper part (1) and the lower part (3) is h, and half the difference in length between the upper part (1) and the lower part (3) is x, h: x ranges from 2 to 5.

7. Counter-current classifier according to claim 1, characterized in that the distance between the nozzles (8) decreases linearly in sequence from the central axis outwards, the ratio of the minimum distance to the maximum distance between the nozzles (8) being equal to the ratio of the lengths of the upper part (1) and the lower part (3).

8. Countercurrent classifier according to claim 1, characterized in that a feed pipe (10) is arranged above the upper part (1), the feed pipe (4) being in communication with the feed pipe (10).

9. Counterflow classifier according to claim 1, characterized in that the lower part (3) is provided with a counterflow water conduit (11), the water inlet pipe (5) being in communication with the conduit (11).

10. Countercurrent classifier according to claim 1, characterized in that the upper part (1) is provided with an automatic control valve (12) and its end is connected to the discharge pipe (6).