Adjustable spiral chute lattice bar based on ore pulp flow velocity and design method thereof

Abstract

The invention provides an adjustable spiral chute lattice bar based on the flow velocity of ore pulp and a design method of the adjustable spiral chute lattice bar, and relates to the technical field of spiral chute structures.The design method comprises the steps that S1, the height of the adjustable lattice bar is selected; s2, determining radiuses of a starting point and an end point of each lattice bar; s3, selecting the width of lattice bars; s4, selecting an interval angle between adjacent lattice bars, and determining the total number of the lattice bars; s5, optimal deflection angles of lattice bars under different working conditions are selected, and the stiffness coefficient of springs in the adjustable structure is determined; s6, the length and height of lattice bar limiting transverse columns are selected, and the positions of the limiting transverse columns are determined; and S7, checking the deflection angle of the designed adjustable lattice bars and the sorting performance of the spiral chute, if the performance meets the standard, ending the design, and otherwise, repeating the steps S1-S6. The adjustable lattice bars can adapt to the change of the flow velocity of the ore pulp, so that the separation effect of the spiral chute is improved, and the spiral chute can keep efficient and stable performance at different flow velocities of the ore pulp.

Description

Technical Field

[0001] The invention relates to the technical field of spiral chute structures, and in particular to adjustable spiral chute gratings based on ore pulp flow velocity and a design method thereof. Background Art

[0002] Spiral chute separation is a gravity separation method that uses the principle of flow film gravity and inclined flow. It can complete the separation in a very thin slurry flow layer, and has a high separation accuracy for coarse and fine heavy minerals. Compared with other gravity separation technologies, spiral chute separation has the advantages of large processing capacity, low energy consumption, no pollution, high separation efficiency, and wide separation range. It is widely used in the fields of heavy mineral pre-selection, tailings removal and concentration.

[0003] A large number of tests and production practices have shown that loosening, stratification and separation are the basic processes of spiral chute sorting. The loosening means, loosening methods and control of looseness will directly affect the final result of sorting. Many researchers have introduced special trough surface structures, such as wedge-shaped grooves, spiral grooves and rifling bars, to improve the sorting effect of spiral chutes. However, the design of these structures is usually achieved by directly modifying the spiral chute structure or fixing it on the trough surface. In the case of excessive changes in the slurry flow rate, the above-mentioned improvement measures are not significant for improving the sorting effect of the spiral chute, and sometimes even have a negative impact. Therefore, it is urgent to develop a new technology or method to adapt to the changes in the slurry flow rate, so as to improve the sorting effect of the spiral chute and ensure that it can maintain high efficiency and stable performance at different slurry flow rates.

[0004] In the prior art, publication number CN222112140U discloses a spiral chute ore separation device, including an ore feeder, an ore feed trough, a bracket and a spiral chute, the spiral chute is arranged and fixed on the bracket, the ore feeder is arranged above the spiral chute, the ore feeder is fixedly connected to the top of the ore feeder, the lower end of the spiral chute is provided with an intercepting trough, the lower end of the intercepting trough is provided with an ore receiving trough, the spiral chute is provided with a groove at the bottom of the trough located above the intercepting trough, and the groove is provided with a filter screen and a drum. The prior art flushes and filters the slurry inside the spiral chute through a flushing mechanism and a filter screen, and at the same time, a driving mechanism drives the first rotating shaft to drive the drum to roll, and the rolling direction of the upper part of the drum is opposite to the direction of the water flow of the flushing mechanism, so that the coarse ore in the ore slurry can be intercepted, reducing or eliminating the clogging of the filter screen by the coarse ore, and at the same time, the rolling friction and vibration can also cause the ore blocked on the filter screen to fall off, thereby improving the efficiency of ore separation. However, the existing technology still has shortcomings. When sorting the slurry, the fixed working mode is not sufficient to cope with the high-precision sorting of the slurry at different flow rates, and cannot ensure that the spiral chute maintains high efficiency and stable performance at different slurry flow rates.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0006] The object of the present invention is to provide an adjustable spiral chute grid based on slurry flow rate and a design method thereof to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An adjustable spiral chute grating based on slurry flow rate and a design method thereof, the spiral chute is composed of a chute body, adjustable gratings and an adjustment structure; the chute body is composed of an inner chute wall, an outer chute wall and a chute surface, and the chute surface is provided with adjustable gratings extending from the outer chute wall to the inner chute wall, the adjustment structure comprises a rotating shaft fixedly mounted on the outer chute wall, a spring, hooks fixedly mounted at both ends of the spring, a limiting horizontal column fixedly mounted on the outer chute wall and sliding through the spring along the axial direction of the spring, and the rotating shaft rotates through one end of the adjustable grating close to the outer chute wall, and the two ends of the spring are respectively fixed to the outer chute wall and the adjustable grating by hooks, and the specific steps include:

[0009] S1: Select the height of the adjustable grid;

[0010] S2: Select the type of adjustable grid and determine the starting and ending radii of the grid;

[0011] S3: Select the width of the adjustable grid;

[0012] S4: Selecting the spacing angles of adjacent adjustable lattices to determine the total number of adjustable lattices;

[0013] S5: Select the optimal deflection angle of the adjustable lattice under different working conditions and determine the spring stiffness coefficient;

[0014] S6: Select the length and height of the limit horizontal column in the adjustment structure and determine the position of the limit horizontal column;

[0015] S7: Check the deflection angle of the designed adjustable grid and the separation performance of the spiral chute. If the performance meets the standard, end the design, otherwise repeat steps S1-S6.

[0016] Furthermore, the height of the adjustable gratings gradually decreases from the outer trough wall side to the inner trough wall side of the spiral chute until it is flush with the trough surface. The multiphase flow model is used as the VOF model to simulate the gas-liquid two-phase flow field of the spiral chute when the adjustable gratings are not provided. According to the calculation results, the flow film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum flow film thickness of the middle section of the gas-liquid two-phase flow field when the adjustable gratings are not provided.

[0017] Among them, the height of the outer groove wall is h max Range: δ max ≤h max ≤0.6δ max , where δ max It is the maximum thickness of the flow film in the middle section of the gas-liquid two-phase flow field when the spiral chute is not equipped with adjustable grid bars.

[0018] Furthermore, the adjustable lattice is in the form of a straight line, with one end of the adjustable lattice close to the outer groove wall as the starting end, and one end of the adjustable lattice close to the inner groove wall as the ending end, and the point radius of the adjustable lattice is The range of the end radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0;

[0019] Wherein D is the outer diameter of the spiral chute, r0 is the radial distance of the zoning boundary of the mineral particles in the spiral chute, the starting radius of the adjustable grid is the distance from the center of the spiral chute to the starting end of the adjustable grid on the outer chute wall, and the ending radius of the adjustable grid is the distance from the center of the spiral chute to the ending end of the adjustable grid.

[0020] Furthermore, the adjustable grid bars are designed with equal width, and the width range is: 20d max ≤w≤60d max , where d max is the maximum particle size of the ore particles; w is the width of the adjustable grid.

[0021] Furthermore, from the entrance to the exit of the spiral chute, the interval angles of the adjacent adjustable gratings are uniformly increased, and the angle from the i-th adjustable grating to the i+1-th adjustable grating is denoted as θ i , and its calculation formula is:

[0022] θ i =θ1+(i-1)m

[0023] Where θ1 is the first adjacent angle near the entrance, and its value range is m is the interval angle tolerance, the range is: i is the index of the adjustable grid, and i∈[1,n];

[0024] n is the total number of adjustable lattices, and the calculation formula for the total number of adjustable lattices is:

[0025]

[0026] Wherein, N is the total number of spiral chute turns.

[0027] Further, the method for determining the spring stiffness coefficient is: determine the first stiffness coefficient of each spring according to the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, outer trough wall side height, starting radius of the adjustable grid, end radius of the adjustable grid, grid gravity, sliding friction factor and friction coefficient; then generate the first spring correction coefficient through the shear modulus error of the spring, the maximum standard temperature difference and the optimal grid deflection angle, and use each first spring correction coefficient to the first stiffness coefficient to obtain the stiffness coefficient of each spring; the shear modulus error is the difference between the shear modulus of the spring in the natural state and the fully compressed state;

[0028] The specific logic for obtaining the maximum standard temperature difference is as follows: obtain the historical maximum temperature and the historical minimum temperature of the area where the spring is located, calculate the difference between the historical maximum temperature and the spring standard maximum temperature, and the difference between the historical minimum temperature and the spring standard minimum temperature, and take the maximum value between the two differences as the maximum standard temperature difference;

[0029] The specific formula for calculating the first stiffness constant of each spring is:

[0030]

[0031] Among them, k i is the first stiffness coefficient of the spring connected to the i-th adjustable lattice, β d is the optimal grid deflection angle for designing slurry flow, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, V i is the slurry velocity at the midpoint of the i-th grid, h max is the height of the outer groove wall, r1 is the starting radius of the adjustable grid, t2 is the ending radius of the adjustable grid; G is the grid weight; μ is the sliding friction factor; λ is the friction coefficient, and the value range is 0<λ<1;

[0032] The specific formula used to generate the first spring correction coefficient is:

[0033] ξ=[β d -β0-sin(β d -β0)]+ΔΓ 2 +log 10 ΔΓ+e -ΔT

[0034] Among them, ξ is the first spring correction coefficient, ΔΓ is the shear modulus error of the spring, ΔT is the maximum standard temperature difference, and the specific formula for calculating the stiffness coefficient of each spring is: K i =k i (1+ξ)

[0035] Among them, K iis the stiffness coefficient of the spring connected to the i-th adjustable lattice.

[0036] Furthermore, the range of the bottom height of the limit horizontal column is: 0.3h max ≤h r ≤0.8h max

[0037] Among them, h r is the bottom height of the limit horizontal column, h max is the side height of the outer groove wall, and the bottom end height of the horizontal column is the distance from the connection between the limiting horizontal column and the outer groove wall to the bottom end of the outer groove wall;

[0038] The specific formula for designing the length of the limit horizontal column is:

[0039]

[0040] Where, L r is the length of the limit horizontal column, L1 is the distance between the end of the limit horizontal column close to the outer groove wall and the rotating shaft; the value range is: 1.5w≤L1≤3w; L2 is the distance between the rotating shaft and the hook on the grid bar; the value range is: w is the width of the adjustable grid, r1 is the starting radius of the adjustable grid, and r2 is the ending radius of the adjustable grid;

[0041] According to h r , L1 and L2 to determine the installation position of the limiting cross bar.

[0042] Furthermore, the specific logic for the deflection angle calibration of the adjustable grating and the sorting performance calibration of the spiral chute is as follows: based on the structural parameters of the above design, the adjustable grating is processed on the existing spiral chute model, and the segment model test is carried out;

[0043] Observe the deflection angle β of the grid bars under the conditions of minimum slurry flow and maximum slurry flow min ′、β max ′, and compared with the corresponding optimal grid deflection angle, if and If the deflection angle calibration meets the requirements, otherwise, repeat steps S1-S6;

[0044] The recovery rate of the target mineral particles in the concentrate belt is extracted. If the recovery rate of the spiral chute with the designed adjustable grid bars is higher than that of the existing spiral chute, the separation performance meets the design requirements, otherwise repeat steps S1-S6;

[0045] The designed adjustable grid deflection angle calibration and spiral chute sorting performance calibration both met the design requirements, and the design was completed.

[0046] The present invention further provides an adjustable spiral chute grating based on ore slurry flow rate, wherein the adjustable spiral chute grating based on ore slurry flow rate is designed by the design method of the adjustable spiral chute grating based on ore slurry flow rate.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention arranges adjustable gratings on the surface of the spiral chute and systematically determines the key structural parameters of the gratings, including the height, width, and radius of the starting and ending ends of the gratings. The adjustable gratings can adapt to changes in the slurry flow rate, thereby significantly improving the sorting effect of the spiral chute and ensuring that the spiral chute can maintain high efficiency and stable performance at different slurry flow rates. The design method can achieve its fast and efficient design, providing effective technical support for improving the performance of the spiral chute. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 It is a schematic diagram of the overall method flow of the present invention.

[0050] Figure 2 It is an overall schematic diagram of a spiral chute and adjustable gratings according to an embodiment of the present invention.

[0051] Figure 3 It is a top view of the spiral chute and adjustable grating provided in an embodiment of the present invention.

[0052] Figure 4 It is a general schematic diagram of the adjustable grid and the adjustment structure provided by the embodiment of the present invention.

[0053] Figure 5 It is a partial schematic diagram of the adjustable grid and the adjustment structure provided by the embodiment of the present invention.

[0054] Figure 6 It is the radial distribution of the flow film thickness in the middle section of the spiral chute provided by the embodiment of the present invention.

[0055] In the figure: 1, groove body, 2, adjustable grid, 3, adjustment structure, 11, inner groove wall, 12, outer groove wall, 13, groove surface, 31, rotating shaft, 32, spring, 33, plug hook, 34, limiting horizontal column. DETAILED DESCRIPTION

[0056] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0057] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0058] Example:

[0059] See also Figure 1-6 , the present invention provides a technical solution:

[0060] An adjustable spiral chute grating based on slurry flow rate and a design method thereof, the spiral chute is composed of a chute body 1, adjustable gratings 2 and an adjustment structure 3; the chute body 1 is composed of an inner chute wall 11, an outer chute wall 12 and a chute surface 13, and the chute surface 13 is provided with an adjustable grating 3 extending along the outer chute wall 12 to the inner chute wall 11, the adjustment structure comprises a rotating shaft 31 fixedly mounted on the outer chute wall, the rotating shaft 31 passes through the end of the adjustable grating 2 and is fixed to the outer chute wall 12 through a fixed block (not shown), a spring 32, hooks 33 fixedly mounted at both ends of the spring 32, a limiting horizontal column 34 fixedly mounted on the outer chute wall 12 and sliding through the spring 32 along the axial direction of the spring 32, and the rotating shaft 3 rotates through one end of the adjustable grating 3 close to the outer chute wall 12, and the two ends of the spring are respectively fixed to the outer chute wall 12 and the adjustable grating 3 through the hooks 33, and the specific steps include:

[0061] S1: Select the height of the adjustable grid;

[0062] The height of the adjustable gratings gradually decreases from the outer trough wall side to the inner trough wall side of the spiral chute until it is flush with the trough surface. The multiphase flow model is used as the VOF model to simulate the gas-liquid two-phase flow field of the spiral chute when the adjustable gratings are not provided. According to the calculation results, the flow film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum flow film thickness of the middle section of the gas-liquid two-phase flow field when the adjustable gratings are not provided.

[0063] Among them, the height of the outer groove wall is h max Range: δ max ≤h max ≤0.6δ max , where δmax It is the maximum thickness of the flow film in the middle section of the gas-liquid two-phase flow field when the spiral chute is not equipped with adjustable grid bars.

[0064] Preferably, the maximum film thickness is obtained based on the numerical calculation method as δ max =10.5mm.

[0065] Adjustable grid height h max =6mm.

[0066] S2: Select the type of adjustable grid and determine the starting and ending radii of the grid;

[0067] The adjustable lattice is in the form of a straight line, with the end of the adjustable lattice close to the outer groove wall as the starting end, and the end of the adjustable lattice close to the inner groove wall as the ending end, and the starting radius of the adjustable lattice is The range of the end radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0;

[0068] Wherein D is the outer diameter of the spiral chute, r0 is the radial distance of the zoning boundary of the mineral particles in the spiral chute, the starting radius of the adjustable grid is the distance from the center of the spiral chute to the starting end of the adjustable grid on the outer chute wall, and the ending radius of the adjustable grid is the distance from the center of the spiral chute to the ending end of the adjustable grid.

[0069] Preferably, the outer diameter of the spiral chute is 400 mm. At the same time, based on the numerical calculation method, the radial distance r0 of the boundary between the heavy ore particles and the light ore particles at the outlet of the spiral chute is obtained to be 78 mm when no adjustable grid bars are provided.

[0070] Preferably, the starting point radius r1 of the adjustable lattice is 200 mm, and the ending point radius r2 of the adjustable lattice is 80 mm.

[0071] S3: Select the width of the adjustable grid;

[0072] The adjustable grids are designed with equal width, and the width range is: 20d max ≤w≤60d max , where d max is the maximum particle size of the ore particles; w is the width of the adjustable grid.

[0073] Preferably, it is known that the particle size of the iron ore is 0.09 mm, and the adjustable grid width w is 4.5 mm.

[0074] S4: Selecting the spacing angles of adjacent adjustable lattices to determine the total number of adjustable lattices;

[0075] From the entrance to the exit of the spiral chute, the interval angles of the adjacent adjustable gratings increase uniformly, and the angle from the i-th adjustable grating to the i+1-th adjustable grating is denoted as θ i , and its calculation formula is:

[0076] θ i =θ1+(i-1)m

[0077] Where θ1 is the first adjacent angle near the entrance, and its value range is m is the interval angle tolerance, the range is: i is the index of the adjustable grid bar, and i∈[1,n].

[0078] n is the total number of adjustable lattices, and the calculation formula for the total number of adjustable lattices is:

[0079]

[0080] Wherein, N is the total number of spiral chute turns.

[0081] Preferably, the first adjacent angle close to the entrance is taken Interval angle tolerance The total number of grid bars n=18.

[0082] S5: Select the optimal deflection angle of the adjustable lattice under different working conditions and determine the spring stiffness coefficient;

[0083] The method for determining the spring stiffness coefficient is as follows: determining the first stiffness coefficient of each spring according to the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, height of the outer groove wall of the adjustable grid, starting radius of the adjustable grid, end radius of the adjustable grid, grid gravity, sliding friction factor and friction coefficient; then generating the first spring correction coefficient through the shear modulus error of the spring, the maximum standard temperature difference and the optimal grid deflection angle, and obtaining the stiffness coefficient of each spring by using each first spring correction coefficient to the first stiffness coefficient; the shear modulus error is the difference between the shear modulus of the spring in the natural state and the fully compressed state;

[0084] The specific logic for obtaining the maximum standard temperature difference is: obtain the historical maximum temperature and the historical minimum temperature of the area where the spring is located, calculate the difference between the historical maximum temperature and the standard maximum temperature of the spring, and the difference between the historical minimum temperature and the standard minimum temperature of the spring, and take the maximum value between the two differences as the maximum standard temperature difference; the historical maximum temperature and the historical minimum temperature are the maximum temperature and the minimum temperature of the applicable area the next day, and the standard maximum temperature and the standard minimum temperature of the spring are obtained by checking the spring specifications.

[0085] Among them, the spring shear modulus error, the maximum standard temperature difference and the optimal grid deflection angle are all dedimensionalized data.

[0086] The specific formula for calculating the first stiffness constant of each spring is:

[0087]

[0088] Among them, k i is the first stiffness coefficient of the spring connected to the i-th adjustable lattice, β d is the optimal grid deflection angle for designing slurry flow, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, V i is the slurry velocity at the midpoint of the i-th grid, h max is the height of the outer groove wall side of the adjustable grid, r1 is the starting radius of the adjustable grid, r2 is the ending radius of the adjustable grid; G is the grid weight; μ is the sliding friction factor; λ is the friction coefficient, and the value range is 0<λ<1. The sliding friction factor and friction coefficient are measured in the laboratory.

[0089] The specific formula used to generate the first spring correction coefficient is:

[0090] ξ=[(β d -β0)*sin(β d -β0)]+ΔΓ 2 +log 10 1+ΔΓ+e -ΔT

[0091] Where, ξ is the first spring correction coefficient, ΔΓ is the shear modulus error of the spring, ΔT is the maximum standard temperature difference, (β d -β0)*sin(β d -β0) is to take into account the nonlinear change characteristics of the deflection angle, and the stiffness coefficient is corrected by the dynamic response of the spring in the form of a function. The larger its value is, the greater the degree to which the stiffness coefficient needs to be corrected; β d -β0 deviation is small, usually lower than Therefore, as the deviation angle increases (β d -β0)*sin(β d -β0) that is, the magnitude of the deviation correction will also increase; ΔΓ 2 +log 10 1+ΔΓ is the degree of correction caused by the change of shear modulus when the spring is working and the influence on the stiffness coefficient. The larger the error of the shear modulus of the spring, the greater the ΔΓ 2 +log 10 The larger the ΔΓ is, the greater the degree of correction of the stiffness coefficient deviation is. 2 In order to amplify the sensitivity to the deviation of the stiffness coefficient, log10 ΔΓ is a smoothing correction mechanism to prevent excessive correction due to the deviation of the stiffness coefficient. -ΔT In order to take into account the extremely high temperature and extremely low temperature weather conditions, the spring accuracy coefficient is corrected. The larger the value, the greater the degree of correction to the spring. The negative exponential form of e is taken, one is to limit its value to within 1, and the other is to prevent over-correction.

[0092] The specific formula used to calculate the stiffness coefficient of each spring is:

[0093] K i =k i (1+ξ)

[0094] Among them, K i is the stiffness coefficient of the spring connected to the i-th adjustable lattice.

[0095] Preferably, the adjustable grid material is selected from silica gel, which has a small mass and the friction force can be approximately ignored; taking the first grid near the inlet as an example, the initial deflection angle of the grid is Based on numerical calculation and genetic algorithm, the optimal grid deflection angle of spiral chute is obtained under the design slurry flow rate Qd = 0.72m3 / h Maximum slurry flow Q max The optimal grid deflection angle under And extract the slurry flow velocity V1=1m / s at the midpoint of the grid, then the first spring coefficient k1:

[0096]

[0097] Take the spring shear modulus error ΔΓ=0.02, the maximum standard temperature difference ΔT=10

[0098] ξ=[(β d -β0)*sin(β d -β0)]+ΔΓ 2 +log 10 1+ΔΓ+e -ΔT

[0099] ≈0.0304+0.0004+0.0086+4.54×10 -5 ≈0.0395

[0100] K1=(1+0.0395)×13=13.5135N / m

[0101] S6: Select the length and height of the limit horizontal column in the adjustment structure and determine the position of the limit horizontal column;

[0102] The value range of the bottom height of the limit horizontal column is: 0.3h max≤h r ≤0.8h max

[0103] Among them, h r is the bottom height of the limit horizontal column, h max is the side height of the outer groove wall, and the bottom end height of the horizontal column is the distance from the connection between the limiting horizontal column and the outer groove wall to the bottom end of the outer groove wall;

[0104] The specific formula for designing the length of the limit horizontal column is:

[0105]

[0106] Where, L r is the length of the limit horizontal column, L1 is the distance between the end of the limit horizontal column close to the outer groove wall and the rotating shaft; the value range is: 1.5w≤L1≤3w; L2 is the distance between the rotating shaft and the hook on the grid bar; the value range is: w is the width of the adjustable grid, r1 is the starting radius of the adjustable grid, and r2 is the ending radius of the adjustable grid;

[0107] According to h r , L1 and L2 to determine the installation position of the limiting cross bar.

[0108] Preferably, the distance L1 between the root of the limiting horizontal column and the rotating shaft is 6 mm, the distance L2 between the shaft and the hook on the grid is 6 mm, and the length L of the limiting horizontal column is r Take 21mm, the bottom height of the limit horizontal column h r Take 4.5mm.

[0109] S7: Check the deflection angle of the designed adjustable grid and the separation performance of the spiral chute. If the performance meets the standard, end the design, otherwise repeat steps S1-S6.

[0110] The specific logic for the deflection angle calibration of the adjustable grating and the separation performance calibration of the spiral chute is as follows: based on the structural parameters of the above design, the adjustable grating is processed on the existing spiral chute model, and the segment model test is carried out;

[0111] Observe the deflection angle β of the grid bars under the conditions of minimum slurry flow and maximum slurry flow min ′、β max ′, and compared with the corresponding optimal grid deflection angle, if and If the deflection angle calibration meets the requirements, otherwise, repeat steps S1-S6;

[0112] The recovery rate of target mineral particles in the concentrate belt is extracted. If the recovery rate of the spiral chute with adjustable grid bars is higher than that of the existing spiral chute, the sorting performance meets the design requirements, otherwise repeat steps S1-S6; the recovery rate of target mineral particles in the concentrate belt is a conventional technical means for those skilled in the art and will not be elaborated here.

[0113] In the embodiment of the present invention, after verification by model test, the designed adjustable grid deflection angle verification and spiral chute sorting performance verification both meet the design requirements, and the design is completed.

[0114] The present invention further provides an adjustable spiral chute grating based on slurry flow rate, and the adjustable spiral chute grating based on slurry flow rate is designed by the adjustable spiral chute grating design method based on slurry flow rate. The above formulas are all dimensionless and numerical calculations, and the formula is a formula obtained by collecting a large amount of data and performing software simulation to obtain the most recent real situation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0115] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0116] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0117] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A design method for adjustable spiral chute gratings based on slurry flow rate, wherein the spiral chute is composed of a trough body, adjustable gratings and an adjustment structure; the trough body is composed of an inner trough wall, an outer trough wall and a trough surface, and the trough surface is provided with adjustable gratings extending from the outer trough wall to the inner trough wall, the adjustment structure comprises a rotating shaft fixedly mounted on the outer trough wall, a spring, hooks fixedly mounted at both ends of the spring, a limiting horizontal column fixedly mounted on the outer trough wall and sliding through the spring along the axial direction of the spring, and the rotating shaft rotates through one end of the adjustable grating close to the outer trough wall, and the two ends of the spring are respectively fixed to the outer trough wall and the adjustable grating by hooks, characterized in that The specific steps include: S1: Select the height of the adjustable grid; S2: Select the type of adjustable grid and determine the starting and ending radii of the grid; S3: Select the width of the adjustable grid; S4: Selecting the spacing angles of adjacent adjustable lattices to determine the total number of adjustable lattices; S5: Select the optimal deflection angle of the adjustable lattice under different working conditions and determine the spring stiffness coefficient; S6: Select the length and height of the limit horizontal column in the adjustment structure and determine the position of the limit horizontal column; S7: Check the deflection angle of the designed adjustable grid and the separation performance of the spiral chute. If the performance meets the standard, end the design, otherwise repeat steps S1-S6.

2. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1 is characterized in that: The height of the adjustable gratings gradually decreases from the outer trough wall side to the inner trough wall side of the spiral chute until it is flush with the trough surface. The multiphase flow model is used as the VOF model to simulate the gas-liquid two-phase flow field of the spiral chute when the adjustable gratings are not provided. According to the calculation results, the flow film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum flow film thickness of the middle section of the gas-liquid two-phase flow field when the adjustable gratings are not provided. Among them, the height of the outer groove wall of the adjustable grid is h max Range: δ max ≤h max ≤0.6δ max , where δ max It is the maximum thickness of the flow film in the middle section of the gas-liquid two-phase flow field when the spiral chute is not equipped with adjustable grid bars.

3. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1 is characterized in that: The adjustable lattice is in the form of a straight line, with the end of the adjustable lattice close to the outer groove wall as the starting end, and the end of the adjustable lattice close to the inner groove wall as the ending end, and the starting radius of the adjustable lattice is The range of the end radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0; Wherein D is the outer diameter of the spiral chute, r0 is the radial distance of the zoning boundary of the mineral particles in the spiral chute, the starting radius of the adjustable grid is the distance from the center of the spiral chute to the starting end of the adjustable grid on the outer chute wall, and the ending radius of the adjustable grid is the distance from the center of the spiral chute to the ending end of the adjustable grid.

4. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1 is characterized in that: The adjustable grid is designed with equal width, and its width range is: 20d max ≤w≤60d max , where d max is the maximum particle size of the ore particles; w is the width of the adjustable grid.

5. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1 is characterized in that: From the entrance to the exit of the spiral chute, the interval angles of the adjacent adjustable gratings increase uniformly, and the angle from the i-th adjustable grating to the i+1-th adjustable grating is denoted as θ i , and its calculation formula is: i i =θ1+(i-1)m Where θ1 is the first adjacent angle near the entrance, and its value range is m is the interval angle tolerance, the range is: i is the index of the adjustable grid, and i∈[1,n]; n is the total number of adjustable lattices, and the calculation formula for the total number of adjustable lattices is: Wherein, N is the total number of spiral chute turns.

6. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1, characterized in that: The method for determining the spring stiffness coefficient is as follows: determining the first stiffness coefficient of each spring according to the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, height of the outer groove wall of the adjustable grid, starting radius of the adjustable grid, end radius of the adjustable grid, grid gravity, sliding friction factor and friction coefficient; then generating the first spring correction coefficient through the shear modulus error of the spring, the maximum standard temperature difference and the optimal grid deflection angle, and obtaining the stiffness coefficient of each spring by using each first spring correction coefficient to the first stiffness coefficient; the shear modulus error is the difference between the shear modulus of the spring in the natural state and the fully compressed state; The specific logic for obtaining the maximum standard temperature difference is as follows: obtain the historical maximum temperature and the historical minimum temperature of the area where the spring is located, calculate the difference between the historical maximum temperature and the spring standard maximum temperature, and the difference between the historical minimum temperature and the spring standard minimum temperature, and take the maximum value of the two differences as the maximum standard temperature difference; The specific formula for calculating the first stiffness coefficient of each spring is: Among them, k i is the first stiffness coefficient of the spring connected to the i-th adjustable lattice, β d is the optimal grid deflection angle for designing slurry flow, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, V i is the slurry velocity at the midpoint of the i-th grid, h max is the height of the outer groove wall of the adjustable lattice, r1 is the starting radius of the adjustable lattice, r2 is the ending radius of the adjustable lattice; G is the weight of the lattice; μ is the sliding friction factor; λ is the friction coefficient, and the value range is 0<λ<1; The specific formula used to generate the first spring correction coefficient is: ξ=[β d -β0-sin(β d -β0)]+ΔΓ 2 +log 10 DG+e -ΔT Where ξ is the first spring correction coefficient, ΔΓ is the shear modulus error of the spring, ΔT is the maximum standard temperature difference, The specific formula used to calculate the stiffness coefficient of each spring is: K i =k i (1+ξ) Among them, K i is the stiffness coefficient of the spring connected to the i-th adjustable lattice.

7. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1, characterized in that: The value range of the bottom height of the limit horizontal column is: 0.3h max ≤h r ≤0.8h max Among them, h r is the bottom height of the limit horizontal column, h max The height of the outer groove wall side of the adjustable lattice bar, the bottom end height of the horizontal column is the distance from the connection between the limiting horizontal column and the outer groove wall to the bottom end of the outer groove wall; The specific formula for designing the length of the limit horizontal column is: Where, L r is the length of the limit horizontal column, L1 is the distance between the end of the limit horizontal column close to the outer groove wall and the rotating shaft; the value range is: 1.5w≤L1≤3w; L2 is the distance between the rotating shaft and the hook on the grid bar; the value range is: w is the width of the adjustable grid, r1 is the starting radius of the adjustable grid, and r2 is the ending radius of the adjustable grid; According to h r , L1 and L2 to determine the installation position of the limiting cross bar.

8. The method for designing adjustable spiral chute gratings based on slurry flow rate according to claim 1, characterized in that: The specific logic for the deflection angle calibration of the adjustable grid bars and the sorting performance calibration of the spiral chute is as follows: based on the structural parameters of the above design, the adjustable grid bars are processed on the existing spiral chute model, and the adjustable model test is carried out; Observe the deflection angle β of the grid bars under the conditions of minimum slurry flow and maximum slurry flow min ′ , β max ′ , and compared with the corresponding optimal grid deflection angle. and If the deflection angle calibration meets the requirements, otherwise, repeat steps S1-S6; The recovery rate of the target mineral particles in the concentrate belt is extracted. If the recovery rate of the spiral chute with the designed adjustable grid bars is higher than that of the existing spiral chute, the separation performance meets the design requirements, otherwise repeat steps S1-S6; The designed adjustable grid deflection angle calibration and spiral chute sorting performance calibration both met the design requirements, and the design was completed.

9. An adjustable spiral chute grid based on slurry flow rate, characterized in that; The adjustable spiral chute gratings based on slurry flow rate are designed by the adjustable spiral chute gratings based on slurry flow rate design method described in any one of claims 1-8.

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