A supergravity centrifugal cyclone desliming device for slime ore pulp grading desliming

Abstract

The present application relates to coal slime ore pulp grading desliming technical field, specifically a kind of for coal slime ore pulp grading desliming supergravity centrifugal cyclone desliming device, including shell, the shell is arranged with cylindrical screen, the screen inside forms stirring cavity, the interlayer between screen and shell constitutes impurity flow guide cavity;Screen is coaxially rotationally connected with stirring impeller, and the blade of stirring impeller is sequentially staggered with the stirring grid of coal slurry and the stirring wall of driving coal slurry rotation along stirring shaft axial direction, along the circumferential direction of stirring impeller, the stirring grid and stirring wall of adjacent blade located on the same circumference are staggered with each other;The present application can effectively separate coal particles and high-ash fine mud in coal slime, and then realize the desliming purpose of coal slime.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal slime slurry grading desliming, and particularly relates to a supergravity centrifugal cyclone desliming device for coal slime slurry grading desliming. BACKGROUND

[0002] With the promotion of coal grading and clean and efficient utilization, the fine washing and processing requirements for coal are more and more strict, not only the ash content of clean coal products is strictly controlled, but also the qualified rate, yield and production rate of clean coal under corresponding conditions are required to be improved. In the coal washing and processing technology, there are mainly dense medium washing and flotation, and the flotation washing process belongs to a micro-particle interface separation process, the interface property difference between particles is enlarged by adding reagents, so that separation is realized. In the process of flotation separation, there are many factors affecting the separation, one of which is the size of the mud content, which has a direct impact on the quality of the clean coal product. Since the main clay minerals in the coal slime entering the flotation process are montmorillonite, kaolinite, illite and quartz, the characteristics of which are non-combustible, easy to swell when meeting water, forming small particles with particle size between several microns and several hundred microns, and negatively charged, the particle surface is hydrophilic, and is easily adsorbed on the surface of coal particles, in the process of flotation separation, it is easy to be entrained by mechanical, water flow and bubbles into the clean coal product, thus forming fine mud cover pollution to the clean coal product, resulting in high ash content of the clean coal. In order to reduce the above-mentioned high-ash fine mud content, the desliming treatment is carried out on the flotation feed before flotation, the deep cone desliming is adopted, and the desliming is realized according to the difference in settling velocity of coal particles and high-ash fine mud particles, but the desliming effect is general, because the high-ash fine mud formed by the clay minerals in the slurry has a negative surface charge, which is easily adsorbed on the surface of coal particles and cannot be removed, and part of the high-ash fine mud has the same settling velocity as the coal particles, so that it cannot be removed, and thus it is urgent to be solved. SUMMARY

[0003] In order to avoid and overcome the technical problems existing in the prior art, the present application provides a supergravity centrifugal cyclone desliming device for coal slime slurry grading desliming. The present application can effectively separate coal particles and high-ash fine mud in coal slime, and thus realize the desliming purpose of coal slime.

[0004] To achieve the above object, the present application provides the following technical scheme:

[0005] A supergravity centrifugal cyclone desliming device for coal slime slurry grading desliming, comprising an outer shell, a cylindrical screen is arranged in the outer shell, a stirring cavity is formed inside the screen, and an impurity guide cavity is formed between the screen and the outer shell; a stirring impeller is coaxially and rotationally connected in the screen, stirring fences for scattering coal slime and stirring walls for driving the rotation of coal slime are arranged on the blades of the stirring impeller in sequence and staggeredly along the stirring shaft axis, and the stirring fences and the stirring walls on the adjacent blades located on the same circumference are arranged staggeredly.

[0006] As a further scheme of the present application: the stirring grid is provided with grids, and the grids are uniformly distributed on the plate surface of the stirring grid; and the stirring wall is a flat plate structure.

[0007] As a further scheme of the present application: the stirring power of the stirring impeller is P,

[0008]

[0009] wherein ω is a first correction coefficient; ρ is the medium density; n is the stirring speed; D is the inner diameter of the stirring tank of the device, i.e. the inner diameter of the screen; τ is a second correction coefficient; A, B and Q are equation parameters; H is the liquid level height of the ore pulp container; θ is the blade inclination angle of the stirring impeller; b is the blade width; and Re is the Reynolds number.

[0010]

[0011] wherein μ is the medium viscosity.

[0012] As a further scheme of the present application: the screen and the shell are connected with fixing supports, and the fixing supports are arranged equidistantly from top to bottom.

[0013] As a further scheme of the present application: the inner wall surface of the screen is arranged with ultrasonic transducers, and the ultrasonic transducers are uniformly arranged on the inner wall surface of the screen.

[0014] As a further scheme of the present application: the surface area of the stirring grid is greater than the surface area of the stirring wall.

[0015] As a further scheme of the present application: the top of the shell is fixedly installed with a driving motor, the transmission shaft of the driving motor is coaxially and drivingly connected with the stirring shaft, and the transmission shaft is arranged with a rotation speed sensor and a torque sensor.

[0016] As a further scheme of the present application: the top of the shell is arranged with a feeding pipe, the filter screen is arranged below the falling track of the feeding pipe, the bottom of the shell is provided with a second discharging pipe which is communicated with the stirring cavity, and the sidewall of the shell is provided with a first discharging pipe which is communicated with the impurity flow guide cavity.

[0017] As a further scheme of the present application: the first discharging pipe is installed with a first adjusting valve, and the second discharging pipe is installed with a second adjusting valve.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] 1. This invention utilizes a rotating impeller within a stirring chamber formed inside a screen, continuously agitating the slurry and ensuring its constant mixing. The impeller's centrifugal force propels the slurry towards the screen, facilitating screening. The screen's aperture is matched to the diameter of the high-ash fine mud, allowing for separation of coal particles and the mud under centrifugal force. An impurity guide chamber provides a storage space for the separated high-ash fine mud, facilitating its collection. The grid on the stirring grid provides a passageway for the slurry, impacting and separating adhered materials, thus improving filtration efficiency. The arrangement of the stirring walls provides power for slurry agitation, continuously pushing the slurry onto the screen for filtration. The stirring grids and stirring walls at the same position on adjacent blades are arranged in an alternating manner, so that the slurry can be both impacted and dispersed at the same height, and the slurry can be stirred, thus accelerating the filtration speed.

[0020] 2. The mixing formula can accurately calculate the mixing power of the impeller, so that the mixing power can be adjusted in real time according to the actual situation to meet the needs of different working conditions.

[0021] 3. In order to adjust and control the desliming efficiency and effect, the drive motor can control its rotation speed by adjusting the frequency, and simultaneously drive the stirring shaft to rotate. The stirring shaft drives the stirring impeller, thereby controlling the rotation speed of the stirring impeller and thus adjusting and controlling the magnitude of the centrifugal force in the hypergravity centrifugal field. At the same time, speed sensors and torque sensors monitor the current rotation speed and torque of the stirring impeller in real time. That is, by using speed sensors and torque sensors, the optimal speed and torque required for the hypergravity centrifugal field are determined. Different desliming effects and efficiencies are achieved by coordinating the magnitude of the centrifugal force in the hypergravity centrifugal field with the screen.

[0022] 4. An ultrasonic transducer is installed on the screen, which can convert electrical energy into high-frequency, low-amplitude mechanical vibration. On the one hand, it causes cavitation near the particles in the slurry, desorbing and removing the fine high-ash mud adsorbed on the particle surface, thus cleaning the particle surface. On the other hand, it causes the particles near the screen to form a micro-suspension state, allowing fine high-ash mud particles smaller than the screen holes to pass through the screen quickly without clogging the screen holes, thus achieving the effect of screening and screen cleaning. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention.

[0024] Figure 2 This is a schematic diagram of the ultrasonic transducer in this invention.

[0025] Figure 3 This is a schematic diagram of the feed pipe structure in this invention.

[0026] Figure 4 This is a schematic diagram of the structure of the first discharge pipe in this invention.

[0027] In the picture:

[0028] 1. Drive motor; 2. Speed ​​sensor; 3. Torque sensor; 4. Feed pipe; 5. Stirring shaft;

[0029] 6. Ultrasonic transducer; 7. Housing; 8. Screen; 9. Stirring grid; 10. Stirring wall;

[0030] 11. First regulating valve; 12. First discharge pipe; 13. Second regulating valve; 14. Second discharge pipe;

[0031] 15. Fixed support; 16. Agitator impeller. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, the output shaft of the drive motor 1 is reliably connected to the stirring shaft 5 and rotates together with the drive motor 1. A speed sensor 2 and a torque sensor 3 are installed on the stirring shaft 5 to monitor the rotational speed and torque of the stirring in real time. An impeller 16 is fixed on the stirring shaft 5 and rotates synchronously with it. The impeller 16 consists of a stirring grid 9 and a stirring wall 10. Along the axial direction of the stirring shaft 5, stirring grids 9 for spreading coal slime and stirring walls 10 for driving the coal slime to rotate are arranged alternately on the blades of the impeller 16. Along the circumference of the impeller 16, the stirring grids 9 and stirring walls 10 on the same circumference of adjacent blades are staggered.

[0034] The stirring grid 9 has grids evenly distributed on its surface. The grids can be elongated perforated structures, with the length of the holes extending radially along the stirring shaft 5, or they can be arranged perpendicular to the radial direction of the stirring shaft 5. The grids can also be square or round holes, evenly arranged on the stirring grid 9, thus forming a mesh structure.

[0035] The mixing wall 10 is a flat plate structure, and its function is the same as that of the blades on the conventional mixing impeller 16.

[0036] A cylindrical screen 8 is arranged in the shell 7, and the screen 8 is connected with the shell 7 through fixing supports 15, and each fixing support 15 is arranged equidistantly from top to bottom, and the screen 8 is reliably fixed to the shell 7. The screen 8 forms a stirring cavity inside, and the interlayer between the screen 8 and the shell 7 constitutes an impurity guide cavity. The material passing through the screen holes of the screen 8 becomes undersize material, and the undersize material is gathered in the impurity guide cavity between the screen 8 and the shell 7, and flows out from the first discharge pipe 12. The material not passing through the screen holes of the screen 8 becomes oversize material, and the oversize material is finally gathered at the bottom of the device, and flows out through the second discharge pipe 14.

[0037] As shown in Figure 1 and Figure 3 , the feed pipe 4 is tangentially connected with the shell 7, so that the ore pulp tangentially enters into the shell 7 under a certain pressure after being pumped into the device, and forms a spiral flow on the inner wall of the shell 7. The driving motor 1 rotates counterclockwise, and drives the rotating impeller 9 to rotate counterclockwise through the stirring shaft 5, and the rotating direction is consistent with the direction of the tangential feeding. The rotational flow formed by the rotation of the stirring impeller 16 is superimposed on the spiral flow formed by the ore pulp entering into the device along the feed pipe 4, to form a strong turbulent spiral flow field, the supergravity centrifugal effect is stronger, the turbulence degree of the supergravity spiral flow field is enhanced, and the collision and friction between the particles in the flow field and between the particles and the screen are more intense, so that the high-ash fine mud adsorbed on the surface of the coal particles is separated and becomes free state; meanwhile, the rotation speed of the stirring impeller 16 can be adjusted by frequency adjustment of the driving motor 1, the strength of the turbulent spiral flow field is adjusted, and the current rotation speed and torque size are monitored in real time through the rotation speed sensor 2 and the torque sensor 3.

[0038] In order to adjust and control the desliming efficiency and effect, the driving motor 1 can control the rotation speed through frequency adjustment, and drives the stirring shaft 5 to rotate. The stirring shaft 5 drives the stirring impeller 16, so as to control the rotation speed of the stirring impeller 16, and adjust and control the centrifugal force of the supergravity centrifugal field; meanwhile, the rotation speed sensor 2 and the torque sensor 3 monitor the rotation speed and torque size of the stirring impeller 16 in real time, that is, the required rotation speed and torque size of the optimal supergravity centrifugal field are determined through the rotation speed sensor 2 and the torque sensor 3, and the centrifugal force of the supergravity centrifugal field is matched with the screen 8 to realize different desliming effects and efficiencies.

[0039] As shown in Figure 1 and Figure 4 , the oversize material not passing through the screen holes of the screen 8 is gathered at the bottom of the device through spiral motion, and flows out through the second discharge pipe 12 tangentially connected with the bottom of the shell 7, and the second discharge pipe 12 is tangentially connected with the bottom of the shell 7, so as to reduce the resistance of the oversize material flowing out.

[0040] As shown in Figure 2As shown, due to the limited action area of the ultrasonic vibrator, the ultrasonic vibrator 6 is staggered in the vertical direction of the screen 8, which can increase the coverage area of the ultrasonic vibration on the one hand, and on the other hand, the ultrasonic vibrator 6 adopts a rod shape, and the spiral flow state of the ore slurry will collide with the rod-shaped ultrasonic vibrator 6, increasing the turbulence intensity of the ore slurry during spiral motion, enhancing the collision between particles and the collision between particles and the screen 8, and improving the probability of high-ash fine mud desorption from the particle surface and screening.

[0041] In the slime, the solid particles less than 0.045 mm generally have ash content of more than 40%, and the high-ash fine mud is mostly contained. The screen 8 has a screen size of 0.045 mm, and the screen size of the screen 8 can be adjusted according to the characteristics of the high-ash fine mud in the slime slurry. The ultrasonic vibrator 6 is installed on the screen 8, which can convert electrical energy into high-frequency and low-amplitude mechanical vibration. On the one hand, cavitation occurs near the particles in the ore slurry, which desorbs and removes the fine high-ash fine mud adsorbed on the particle surface, achieving the effect of particle surface cleaning. On the other hand, the particles near the screen form a micro-suspension state, so that the fine high-ash fine mud particles smaller than the screen size of the screen 8 quickly pass through the screen without blocking the screen, achieving the effects of screening and cleaning the screen.

[0042] The stirring grid 9 and the stirring wall 10 form the stirring impeller 16. The stirring grid 9 is composed of horizontal and vertical grid bars. When the stirring impeller 16 rotates, the stirring wall 10 and the grid bars of the stirring grid 9 rotate together. Under the action of the grid bars, strong turbulent flow occurs, and the grid bars collide and rub with the solid particles in the ore slurry and between the particles, so that the fine high-ash fine mud adsorbed on the particle surface is desorbed and enters the ore slurry as a free state. When the stirring wall 10 rotates, since the stirring wall 10 is solid, the ore slurry produces spiral centrifugal motion under the rotation of the stirring wall 10. Under the action of centrifugal force, the solid particles gather near the screen 8, and then under the action of the ultrasonic vibrator 6, the particles smaller than the screen size of the screen 8 quickly pass through the screen to become undersize.

[0043] As Figure 1 and Figure 3As shown, the second discharge pipe 14 is provided with the second regulating valve 13, which can regulate and control the flow of the oversize; the first discharge pipe 12 is provided with the first regulating valve 11, which can regulate and control the flow of the undersize; the opening degree of the first regulating valve 11 and the opening degree of the second regulating valve 13 can be adjusted, so that the outflow of the undersize and the outflow of the oversize can be adjusted. The opening degree of the second regulating valve 13 affects the effect and efficiency of the classification desliming; when the opening degree of the second regulating valve 13 is large, the residence time of the material in the device is short, and some fine particles of high-ash fine mud have not had time to pass through the screen holes of the screen 8, becoming the oversize, which greatly affects the effect of the classification desliming, and also causes serious loss of the slurry, so that the supergravity centrifugal spiral flow field formed in the device cannot be maintained; when the opening degree of the second regulating valve 13 is small, the residence time of the material in the device is long, and the spiral flow state of the slurry changes, which greatly affects the efficiency of the classification desliming; when the opening degree of the second regulating valve 11 is small, the slurry passing through the screen holes of the screen 8 fills the space between the screen 8 and the shell 10, and the fine mud particles of high ash passing through the screen holes of the screen 8 return to the spiral flow field through the screen 8, which seriously affects the efficiency and effect of the classification desliming.

[0044] For the coal slime slurry containing different types and contents of clay minerals and different particle surface electricities, different rotation speeds and torques can be set to match the rotation speed and torque corresponding to the coal slime slurry with different desliming characteristics, so that the supergravity centrifugal field matched therewith is constructed, and the best classification desliming effect is achieved; for the coal slime slurry with unknown desliming characteristics, the best rotation speed and torque matching the desliming characteristics can be explored by the device, and the corresponding best classification desliming supergravity centrifugal field is established.

[0045] Since the fine mud particles of high ash in the flotation feed have negative electric charges on the surface, and the coal particles have positive electric charges on the surface, the main force of adsorption of the fine mud particles of high ash on the surface of the coal particles is the electrostatic force. Since different minerals have different negative electric charges on the particles, the electrostatic force of adsorption of the fine mud particles of high ash on the surface of the coal particles is also different. Therefore, according to the size of the different adsorption forces, the screen hole diameter of the inclined screen 8 and the size of the required rotation speed and torque are adjusted, so that the centrifugal force required to overcome the adsorption force is generated, the desorption, movement and screening of the fine mud particles of high ash are realized, and the best desliming treatment of different flotation feed characteristics is completed. When the deslimed slurry is subjected to flotation, the desorption of the fine mud particles of high ash reduces the dosage of the flotation reagent, increases the flotation speed, and improves the flotation efficiency and the quality of the flotation clean coal, and the yield of the flotation clean coal is also improved. At the same time, the ash content of the flotation tailings is greatly improved, which is more conducive to the resource recycling of the flotation tailings.

[0046] In the device, the feed of the ore pulp is tangential feed, and under the action of the feed pressure, a spiral flow state is formed inside the screen 8 and the shell 7, which lays a good foundation for the ore pulp stirring, so the formula of the stirring power P is modified for the ore pulp with tangential feed and forming a spiral flow state, and the modified formula is as follows.

[0047]

[0048] Wherein, ω is the first correction coefficient; ρ is the medium density, kg / m 3 ; n is the stirring speed, r / s; D is the inner diameter of the stirring tank of the device, m, that is, the inner diameter of the screen; τ is the second correction coefficient; A, B, Q are equation parameters, which can be calculated by and H is the liquid level height of the ore pulp container, θ is the blade angle of the stirring impeller, b is the blade width, in the application, since the blade width b and the blade diameter d are fixed, the values of the A, B, Q parameters are also fixed; H is; in the application, since the mechanical vibration effect generated by the ultrasonic wave can promote the diffusion of the ore pulp, and the ultrasonic vibrator 6 adopts a rod shape and is uniformly distributed in staggered manner, which is conducive to promoting and improving the stirring efficiency of the ore pulp, Re is the Reynolds number;

[0049]

[0050] Wherein, μ is the medium viscosity, Pa·s. In the application, the stirring impeller 16 is composed of the stirring grid 9 and the stirring wall 10, the stirring grid 9 can have the cutting and stirring effect on the ore pulp, so that the viscosity of the ore pulp is reduced μ, so that the Reynolds number is increased, thereby reducing the stirring power P, that is, the same stirring efficiency is achieved, the stirring power P required by the application is smaller, that is, the energy input required by the device is smaller. On the contrary, when a certain energy input is provided externally, the application can obtain greater stirring power and stirring efficiency, and realize more efficient desliming effect.

[0051] The above is only the preferred specific embodiment of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the application within the technical range disclosed by the application, which should be covered in the protection scope of the application.

Claims

1. A centrifugal cyclone desliming device for mineral slurry classification and desliming, characterized in that, The device includes an outer shell (7), inside which a cylindrical screen (8) is arranged. The screen (8) forms a stirring chamber, and the interlayer between the screen (8) and the outer shell (7) forms an impurity guiding chamber. A stirring impeller (16) is coaxially rotatably connected inside the screen (8). Along the stirring shaft (5), stirring grids (9) for spraying slurry and stirring walls (10) for driving the slurry to rotate are arranged alternately on the blades of the stirring impeller (16). The stirring grids (9) and stirring walls (10) with adjacent blades on the same circumference are staggered. The stirring grids (9) and stirring walls (10) are staggered on each other. A grid is opened on the stirring grid (9), and each grid is evenly distributed on the plate surface of the stirring grid (9). The stirring wall (10) is a flat plate structure.

2. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 1, characterized in that, The stirring power of the stirring impeller (16) is P. Wherein, ω is the first correction coefficient; ρ is the medium density; n is the stirring speed; D is the inner diameter of the stirring tank of this device, that is, the inner diameter of the screen (8); τ is the second correction coefficient; A, B, Q are equation parameters; H is the liquid level height of the slurry container; θ is the inclination angle of the stirring impeller blade; b is the blade width; Re is the Reynolds number; Where μ is the viscosity of the medium.

3. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 2, characterized in that, A fixed bracket (15) is connected between the screen (8) and the outer shell (7), and the fixed brackets (15) are arranged at equal intervals from top to bottom.

4. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 3, characterized in that, The inner wall of the screen (8) is provided with ultrasonic transducers (6), and each ultrasonic transducer (6) is evenly arranged on the inner wall of the screen (8).

5. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 4, characterized in that, The surface area of ​​the stirring grid (9) is greater than the surface area of ​​the stirring wall (10).

6. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 5, characterized in that, A drive motor (1) is fixedly installed on the top of the outer shell (7). The drive shaft of the drive motor (1) is coaxially connected to the stirring shaft (5), and a speed sensor (2) and a torque sensor (3) are arranged on the drive shaft.

7. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 6, characterized in that, The top of the outer shell (7) is provided with a feed pipe (4), and the filter screen is set below the material falling trajectory of the feed pipe (4). The bottom of the outer shell (7) is provided with a second discharge pipe (14) that communicates with the stirring chamber. The side wall of the outer shell (7) is provided with a first discharge pipe (12) that communicates with the impurity guiding chamber.

8. The centrifugal desliming device for classifying and desliming coal slime slurry according to claim 7, characterized in that, A first regulating valve (11) is installed on the first discharge pipe (12), and a second regulating valve (13) is installed on the second discharge pipe (14).

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