A spiral chute with adjustable gratings based on slurry flow rate and its design method

Abstract

This invention provides a spiral chute with adjustable grid bars based on slurry flow rate and its design method, relating to the technical field of spiral chute structures. The invention includes the following steps: S1: Selecting the height of the adjustable grid bars; S2: Determining the starting and ending radii of the grid bars; S3: Selecting the width of the grid bars; S4: Selecting the interval angle between adjacent grid bars and determining the total number of grid bars; S5: Selecting the optimal deflection angle of the grid bars under different operating conditions and determining the spring stiffness coefficient in the adjustable structure; S6: Selecting the length and height of the grid bar limiting crossbars and determining the position of the limiting crossbars; S7: Verifying the deflection angle of the designed adjustable grid bars and the separation performance of the spiral chute. If the performance meets the standards, the design is terminated; otherwise, steps S1-S6 are repeated. The adjustable grid bars can adapt to changes in slurry flow rate, thereby improving the separation effect of the spiral chute and ensuring that the spiral chute maintains high efficiency and stable performance under different slurry flow rates.

Description

Technical Field

[0001] This invention relates to the field of spiral chute structure technology, specifically to a spiral chute with adjustable grid bars based on slurry flow rate and its design method. Background Technology

[0002] Spiral chute separation is a gravity separation method that utilizes film gravity and inclined plane flow principles. It can complete separation within a very thin slurry layer, achieving high separation accuracy for both coarse and fine heavy minerals. Compared to other gravity separation technologies, spiral chute separation offers advantages such as large throughput, low energy consumption, no pollution, high separation efficiency, and a wide separation range, making it widely used in heavy mineral pre-selection, tailings removal, and refining.

[0003] Extensive testing and production practice have shown that loosening, stratification, and separation are the fundamental processes in spiral chute sorting. The loosening methods, approaches, and control of the degree of loosening directly affect the final sorting results. Many researchers have improved the sorting efficiency of spiral chutes by introducing special chute surface structures, such as wedge-shaped grooves, spiral grooves, and ribbed strips. However, these structural designs are usually achieved by directly modifying the spiral chute structure or fixing it to the chute surface. When the slurry flow rate varies significantly, these improvements are not significant in enhancing the sorting efficiency of spiral chutes, and sometimes even have negative effects. Therefore, there is an urgent need to develop a new technology or method to adapt to changes in slurry flow rate, thereby improving the sorting efficiency of spiral chutes and ensuring their high efficiency and stable performance under different slurry flow rates.

[0004] In the prior art, CN222112140U discloses a spiral sluice box ore separating device, including a feed distributor, a feed trough, a support, and a spiral sluice box. The spiral sluice box is fixedly mounted on the support, the feed trough is positioned above the spiral sluice box, the feed distributor is fixedly connected to the top of the feed trough, the lower end of the spiral sluice box has a cutting groove, and below the cutting groove is a receiving groove. The bottom of the spiral sluice box above the cutting groove has a groove, which contains a filter screen and a roller. This prior art uses a flushing mechanism and a filter screen to flush and filter the slurry inside the spiral sluice box. At the same time, a drive mechanism drives a first rotating shaft to rotate the roller. The upper part of the roller rotates in the opposite direction to the direction of the water flow of the flushing mechanism. This can intercept coarse ore in the slurry, reduce or eliminate coarse ore clogging the filter screen. At the same time, the rolling friction and vibration can also cause the ore clogging the filter screen to fall off, improving the ore separating efficiency. However, existing technologies still have shortcomings. When sorting slurry, a fixed working mode is insufficient to handle high-precision sorting of slurry at different flow rates, and cannot ensure that the spiral chute maintains high efficiency and stable performance under different slurry flow rates.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a spiral chute with adjustable grid bars based on slurry flow rate and a design method thereof, so as to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A design method for a spiral chute with adjustable grid bars based on slurry flow rate, the spiral chute comprising a chute body, adjustable grid bars, and an adjustment structure; the chute body comprises an inner chute wall, an outer chute wall, and a chute surface, and the chute surface is provided with adjustable grid bars extending from the outer chute wall to the inner chute wall; the adjustment structure includes a rotating shaft fixedly installed on the outer chute wall, a spring, hooks fixedly installed at both ends of the spring, and a limiting transverse column fixedly installed on the outer chute wall and sliding through the spring along the spring axis; the rotating shaft rotates through one end of the adjustable grid bars near the outer chute wall, and both ends of the spring are fixed to the outer chute wall and the adjustable grid bars respectively by hooks; the specific steps include:

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

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

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

[0012] S4: Select the angle between adjacent adjustable grid strips to determine the total number of adjustable grid strips;

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

[0014] S6: Select the length and height of the limiting crossbar in the adjustment structure, and determine the position of the limiting crossbar;

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

[0016] Furthermore, the height of the adjustable grid gradually decreases from the outer wall side to the inner wall side of the spiral chute until it is flush with the chute surface. The gas-liquid two-phase flow field of the spiral chute without adjustable grid is simulated by the multiphase flow model for the VOF model. Based on the calculation results, the film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum film thickness of the middle section of the gas-liquid two-phase flow field without adjustable grid.

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

[0018] Furthermore, the adjustable grid strip is a straight line, with the end of the adjustable grid strip closest to the outer wall of the groove as the starting end and the end closest to the inner wall of the groove as the ending end, and the point radius of the adjustable grid strip... The range of the endpoint radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0;

[0019] Where D is the outer diameter of the spiral chute, r0 is the radial distance of the zone boundary of mineral particles in the spiral chute when no adjustable grid is provided, 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 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 strips are designed with equal width, and their width range is 20d. max ≤w≤60d max , where d max is the maximum particle size of the ore; w is the width of the adjustable grid.

[0021] Furthermore, from the inlet to the outlet of the spiral chute, the angle between adjacent adjustable grid strips increases uniformly, and the angle from the i-th adjustable grid strip to the (i+1)-th adjustable grid strip is denoted as θ. i The calculation formula is as follows:

[0022] θ i =θ1+(i-1)m

[0023] In the formula, θ1 is the first adjacent angle near the entrance, and its value range is... m represents the angular tolerance, and its range is: i is the index of the adjustable grid bar, and i∈[1,n];

[0024] n represents the total number of adjustable grid strips. The formula for calculating the total number of adjustable grid strips is:

[0025]

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

[0027] Further, the method for determining the spring stiffness coefficient is as follows: Based on the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, outer tank wall height, starting radius of the adjustable grid, ending radius of the adjustable grid, grid weight, sliding friction coefficient, and friction coefficient, a first stiffness coefficient for each spring is determined. Then, a first spring correction coefficient is generated using the spring's shear modulus error, maximum standard temperature difference, and optimal grid deflection angle. Each first spring correction coefficient is used to correct the first stiffness coefficient, resulting in the stiffness coefficient for each spring. The shear modulus error is the difference between the shear modulus of the spring in its natural state and its fully compressed state.

[0028] The specific logic for obtaining the maximum standard temperature difference is as follows: obtain the historical maximum temperature and 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.

[0029] The specific formula used to calculate the first spring constant of each spring is as follows:

[0030]

[0031] Where, k i β is the first spring constant of the spring connected to the i-th adjustable grid bar. d To determine the optimal grid deflection angle for the slurry flow rate, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, and V... i h is the slurry flow velocity at the midpoint of the i-th grid. max R is the height of the outer wall of the tank; r1 is the starting radius of the adjustable grid bar; r2 is the ending radius of the adjustable grid bar; G is the weight of the grid bar; μ is the sliding friction coefficient; λ is the friction coefficient, with a value range of 0 < λ < 1.

[0032] The specific formula used to generate the first spring correction factor is as follows:

[0033] ξ=[β d -β0-sin(β d -β0)]+ΔΓ 2 +log 10 (1+ΔΓ)+e -ΔT

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

[0035] Among them, K iLet be the spring constant of the spring connected to the i-th adjustable grid bar.

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

[0037] Among them, h r h is the height of the bottom end of the limiting horizontal column. max The height of the outer tank wall side is the height of the bottom end of the horizontal column, which is the distance from the connection between the limiting horizontal column and the outer tank wall to the bottom end of the outer tank wall.

[0038] The specific formula used to design the length of the limiting crossbar is as follows:

[0039]

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

[0041] According to h r L1 and L2 are used to determine the installation position of the limit crossbar.

[0042] Furthermore, the specific logic for verifying the deflection angle of the adjustable grid and the sorting performance of the spiral chute is as follows: based on the structural parameters of the above design, the adjustable grid is processed on the existing spiral chute model, and a segmented model test is conducted.

[0043] Observe the deflection angle β of the grid bars under minimum and maximum slurry flow conditions. min ′、β max And compare it with the corresponding optimal grid deflection angle. and If the deflection angle check meets the requirements, then repeat steps S1-S6;

[0044] The recovery rate of the target mineral particles in the concentrate belt is determined by the following: if the recovery rate of the spiral chute with adjustable grid is higher than that of the existing spiral chute, then the separation performance meets the design requirements; otherwise, repeat steps S1-S6.

[0045] The designed adjustable grid deflection angle and spiral chute sorting performance both met the design requirements, and the design is now complete.

[0046] The present invention further provides a spiral chute with adjustable grid bars based on slurry flow rate, wherein the spiral chute with adjustable grid bars based on slurry flow rate is designed by the spiral chute design method with adjustable grid bars based on slurry flow rate.

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

[0048] This invention utilizes adjustable grid bars on the surface of a spiral chute and systematically determines the key structural parameters of these grid bars, including their height, width, and the radii of their starting and ending points. The adjustable grid bars can adapt to changes in slurry flow rate, thereby significantly improving the separation efficiency of the spiral chute and ensuring its high efficiency and stable performance under different slurry flow rates. The design method enables rapid and efficient design, providing effective technical support for improving the performance of spiral chutes. Attached Figure Description

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

[0050] Figure 2 This is a schematic diagram of the spiral chute and adjustable grid strips according to an embodiment of the present invention.

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

[0052] Figure 4 This is a schematic diagram of the adjustable grid strip and adjustment structure provided in an embodiment of the present invention.

[0053] Figure 5 This is a partial schematic diagram of the adjustable grid strip and adjustment structure provided in an embodiment of the present invention.

[0054] Figure 6 This refers to the radial distribution of the flow film thickness in the middle cross section of the spiral chute provided in this embodiment of the invention.

[0055] In the diagram: 1. Tank body, 2. Adjustable grid bars, 3. Adjustment structure, 11. Inner tank wall, 12. Outer tank wall, 13. Tank surface, 31. Rotating shaft, 32. Spring, 33. Hook, 34. Limiting column. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0057] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only 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] Please see Figure 1-6 , the present invention provides a technical solution:

[0060] A design method for a spiral chute with adjustable grid bars based on slurry flow rate, wherein the spiral chute comprises a chute body 1, adjustable grid bars 2, and an adjustment structure 3; the chute body 1 comprises an inner chute wall 11, an outer chute wall 12, and a chute surface 13, and the chute surface 13 is provided with adjustable grid bars 3 extending from the outer chute wall 12 to the inner chute wall 11; the adjustment structure includes a rotating shaft 31 fixedly installed on the outer chute wall, the end of the rotating shaft 31 passing through the adjustable grid bars 2 being fixed to the outer chute wall 12 by a fixing block (not shown in the figure), a spring 32, hooks 33 fixedly installed at both ends of the spring 32, and a limiting crossbar 34 fixedly installed on the outer chute wall 12 and sliding through the spring 32 along the axial direction of the spring 32; the rotating shaft 3 rotates through the end of the adjustable grid bars 3 near the outer chute wall 12, and both ends of the spring are fixed to the outer chute wall 12 and the adjustable grid bars 3 by hooks 33 respectively; the specific steps include:

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

[0062] The height of the adjustable grid gradually decreases from the outer wall side to the inner wall side of the spiral chute until it is flush with the chute surface. The gas-liquid two-phase flow field of the spiral chute without adjustable grid is simulated by the VOF model using a multiphase flow model. Based on the calculation results, the film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum film thickness of the middle section of the gas-liquid two-phase flow field without adjustable grid.

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

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

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

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

[0067] The adjustable grid strip is a straight line, with the end closest to the outer wall of the groove as the starting point and the end closest to the inner wall as the ending point. The starting radius of the adjustable grid strip is... The range of the endpoint radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0;

[0068] Where D is the outer diameter of the spiral chute, r0 is the radial distance of the zone boundary of mineral particles in the spiral chute when no adjustable grid is provided, 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 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 400mm; at the same time, based on numerical calculation methods, the radial distance r0 of the separation boundary between heavy mineral particles and light mineral particles at the spiral chute outlet is 78mm when no adjustable grid is provided.

[0070] Preferably, the starting radius of the adjustable grid strip is r1 = 200 mm, and the ending radius of the adjustable grid strip is r2 = 80 mm.

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

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

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

[0074] S4: Select the angle between adjacent adjustable grid strips to determine the total number of adjustable grid strips;

[0075] From the inlet to the outlet of the spiral chute, the angle between adjacent adjustable grid strips increases uniformly. The angle from the i-th adjustable grid strip to the (i+1)-th adjustable grid strip is denoted as θ. i The calculation formula is as follows:

[0076] θ i =θ1+(i-1)m

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

[0078] n represents the total number of adjustable grid strips. The formula for calculating the total number of adjustable grid strips is:

[0079]

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

[0081] Preferably, the first adjacent angle closest to the entrance is selected. Interval angle tolerance The total number of grids is n = 18.

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

[0083] The method for determining the spring stiffness coefficient is as follows: First stiffness coefficient for each spring is determined based on the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, height of the outer wall of the adjustable grid, starting radius of the adjustable grid, ending radius of the adjustable grid, grid weight, sliding friction coefficient, and friction coefficient. Then, a first spring correction coefficient is generated using the spring's shear modulus error, maximum standard temperature difference, and optimal grid deflection angle. Each first spring correction coefficient is used to correct the first stiffness coefficient, resulting in the stiffness coefficient for each spring. The shear modulus error is the difference between the shear modulus of the spring in its natural state and its fully compressed state.

[0084] The specific logic for obtaining the maximum standard temperature difference is as follows: obtain the historical maximum and minimum temperatures 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 historical minimum temperature are the maximum and minimum temperatures of the applicable area on the next day, and the standard maximum temperature and standard minimum temperature of the spring are obtained by checking the spring specifications.

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

[0086] The specific formula used to calculate the first spring constant of each spring is as follows:

[0087]

[0088] Where, k i β is the first spring constant of the spring connected to the i-th adjustable grid bar. d To determine the optimal grid deflection angle for the slurry flow rate, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, and V... i h is the slurry flow velocity at the midpoint of the i-th grid. max R1 is the height of the outer groove wall of the adjustable grid, R2 is the starting radius of the adjustable grid, and R2 is the ending radius of the adjustable grid. G is the weight of the grid. μ is the sliding friction coefficient. λ is the friction coefficient, with a value range of 0 < λ < 1. The sliding friction coefficient and friction coefficient are determined by laboratory testing.

[0089] The specific formula used to generate the first spring correction factor is as follows:

[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 used to correct the spring constant by considering the nonlinear variation of the deflection angle, through the dynamic response of the spring in functional form. The larger the value of β0, the greater the degree of correction required for the spring constant; d -β0 deviation is small, typically lower than Therefore, as the deviation angle increases (β) d -β0)*sin(β d -β0) means the magnitude of the deviation correction will also increase; ΔΓ 2 +log 10 (1+ΔΓ) represents the correction degree caused by the change in shear modulus during spring operation, which affects the spring constant. The larger the error in the shear modulus of the spring, the greater the correction ΔΓ. 2 +log 10 The larger (1+ΔΓ) is, the greater the degree of correction for the stiffness coefficient deviation. 2This is to amplify the sensitivity to stiffness coefficient deviation, log 10 (1+ΔΓ) is a smoothing correction mechanism to prevent excessive correction due to stiffness coefficient deviation. -ΔT To account for extreme high and low temperature weather conditions, the spring accuracy coefficient is corrected. The larger the value, the greater the correction to the spring. The negative exponent of e is used, firstly to limit its value to within 1, and secondly to prevent overcorrection.

[0092] The specific formula used to calculate the spring constant of each spring is as follows:

[0093] K i =k i (1+ξ)

[0094] Among them, K i Let be the spring constant of the spring connected to the i-th adjustable grid bar.

[0095] Preferably, the adjustable grid material is silicone, which has a small mass and negligible friction. Taking the first grid near the inlet as an example, the initial deflection angle of the grid is... The optimal grid deflection angle of the spiral chute under the design slurry flow rate Qd = 0.72 m³ / h was obtained based on numerical calculation and genetic algorithm. Maximum slurry flow rate Q max The optimal grid deflection angle And extract the slurry flow velocity V1 = 1 m / s at the midpoint of the grid strip, then the first stiffness coefficient k1 of the spring is:

[0096]

[0097] Assuming the shear modulus error of the spring is ΔΓ = 0.02 and the maximum standard temperature difference is 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 limiting crossbar in the adjustment structure, and determine the position of the limiting crossbar;

[0102] The value range of the bottom height of the limiting crossbar is: 0.3h. max ≤h r ≤0.8h max

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

[0104] The specific formula used to design the length of the limiting crossbar is as follows:

[0105]

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

[0107] According to h r L1 and L2 are used to determine the installation position of the limit crossbar.

[0108] Preferably, the distance L1 from the root of the limiting crossbar to the rotating shaft is 6mm, the distance L2 from the shaft to the hook on the grid bar is 6mm, and the length L of the limiting crossbar is... r Take 21mm, and set the bottom height h of the limiting crossbar. r Take 4.5mm.

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

[0110] The specific logic for verifying the deflection angle of the adjustable grid and the sorting performance of the spiral chute is as follows: Based on the structural parameters of the above design, the adjustable grid is processed on the existing spiral chute model, and a segmented model test is conducted.

[0111] Observe the deflection angle β of the grid bars under minimum and maximum slurry flow conditions. min ′、β max And compare it with the corresponding optimal grid deflection angle. and If the deflection angle check meets the requirements, then repeat steps S1-S6;

[0112] The recovery rate of the target mineral particles extracted from the concentrate belt is determined by the following steps: if the recovery rate of the spiral chute with adjustable grid is higher than that of the existing spiral chute, then the separation performance meets the design requirements; otherwise, steps S1-S6 are repeated. The recovery rate of the target mineral particles extracted from the concentrate belt is a conventional technique for those skilled in the art and will not be elaborated here.

[0113] In this embodiment of the invention, the adjustable grid deflection angle and the spiral chute sorting performance were verified by model tests and both met the design requirements, thus the design was completed.

[0114] This invention also provides a spiral chute with adjustable grid bars based on slurry flow rate, wherein the spiral chute with adjustable grid bars based on slurry flow rate is designed using the aforementioned spiral chute design method with adjustable grid bars based on slurry flow rate. All the above formulas are dimensionless calculations, derived from software simulations using collected data to obtain the most recent realistic results. The preset parameters in the formulas can be set by those skilled in the art according to actual conditions.

[0115] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented in software, the above embodiments can be implemented, in whole or in part, as a computer program product. Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software 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 separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

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

Claims

1. A design method for a spiral chute with adjustable grid bars based on slurry flow rate, the spiral chute comprising a chute body, adjustable grid bars, and an adjustment structure; the chute body comprising an inner chute wall, an outer chute wall, and a chute surface, wherein adjustable grid bars extending from the outer chute wall to the inner chute wall are provided on the chute surface; 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, and a limiting transverse column fixedly mounted on the outer chute wall and sliding through the spring along the spring axis; the rotating shaft rotates through one end of the adjustable grid bars near the outer chute wall, and both ends of the spring are fixed to the outer chute wall and the adjustable grid bars respectively by hooks, characterized in that... The specific steps include: S1: Select the height of the adjustable grid strip; S2: Select the type of adjustable grid strip and determine the starting and ending radii of the grid strip; S3: Select the width of the adjustable grid strip; S4: Select the angle between adjacent adjustable grid strips to determine the total number of adjustable grid strips; S5: Select the optimal deflection angle of the adjustable grid under different working conditions to determine the spring stiffness coefficient; S6: Select the length and height of the limiting crossbar in the adjustment structure, and determine the position of the limiting crossbar; S7: Verify the deflection angle and sorting performance of the adjustable grid designed by the spiral chute. If the performance meets the standard, end the design; otherwise, repeat steps S1-S6.

2. The design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that: The height of the adjustable grid gradually decreases from the outer wall side to the inner wall side of the spiral chute until it is flush with the chute surface. The gas-liquid two-phase flow field of the spiral chute without adjustable grid is simulated by the VOF model using a multiphase flow model. Based on the calculation results, the film thickness distribution of the middle section of the spiral chute can be directly extracted to determine the maximum film thickness of the middle section of the gas-liquid two-phase flow field without adjustable grid. Among them, the adjustable grid outer groove wall side height h max The range is: δ max ≤h max ≤0.6δ max , where δ max The maximum thickness of the flow film at the mid-section of the gas-liquid two-phase flow field when the spiral chute is not equipped with adjustable grid bars.

3. The design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that: The adjustable grid strip is a straight line, with the end closest to the outer wall of the groove as the starting point and the end closest to the inner wall as the ending point. The starting radius of the adjustable grid strip is... The range of the endpoint radius r2 of the adjustable grid is: 0.95r0≤r2≤1.2r0; Where D is the outer diameter of the spiral chute, r0 is the radial distance of the zone boundary of mineral particles in the spiral chute when no adjustable grid is provided, 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 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 design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that: The adjustable grid strips are designed with equal width, and their width range is 20d. max ≤w≤60d max , where d max is the maximum particle size of the ore; w is the width of the adjustable grid.

5. The design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that: From the inlet to the outlet of the spiral chute, the angle between adjacent adjustable grid strips increases uniformly. The angle from the i-th adjustable grid strip to the (i+1)-th adjustable grid strip is denoted as θ. i The calculation formula is as follows: i i =θ1+(i-1)m In the formula, θ1 is the first adjacent angle near the entrance, and its value range is... m represents the angular tolerance, and its range is: i is the index of the adjustable grid bar, and i∈[1,n]; n represents the total number of adjustable grid strips. The formula for calculating the total number of adjustable grid strips is: Where N is the total number of turns of the spiral chute.

6. The design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that, The method for determining the spring stiffness coefficient is as follows: First stiffness coefficient for each spring is determined based on the optimal grid deflection angle, slurry density, initial deflection angle of the adjustable grid, slurry flow rate, height of the outer wall of the adjustable grid, starting radius of the adjustable grid, ending radius of the adjustable grid, grid weight, sliding friction coefficient, and friction coefficient. Then, a first spring correction coefficient is generated using the spring's shear modulus error, maximum standard temperature difference, and optimal grid deflection angle. Each first spring correction coefficient is used to correct the first stiffness coefficient, resulting in the stiffness coefficient for each spring. The shear modulus error is the difference between the shear modulus of the spring in its natural state and its fully compressed state. The specific logic for obtaining the maximum standard temperature difference is as follows: obtain the historical maximum temperature and 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 of the two differences as the maximum standard temperature difference. The specific formula used to calculate the first spring constant of each spring is as follows: Where, k i β is the first spring constant of the spring connected to the i-th adjustable grid bar. d To determine the optimal grid deflection angle for the slurry flow rate, ρ is the slurry density, β0 is the initial deflection angle of the adjustable grid, and V... i h is the slurry flow velocity at the midpoint of the i-th grid. max R is the height of the outer groove wall of the adjustable grid bar; r1 is the starting radius of the adjustable grid bar; r2 is the ending radius of the adjustable grid bar; G is the weight of the grid bar; μ is the sliding friction coefficient; λ is the friction coefficient, with a value range of 0 < λ < 1. The specific formula used to generate the first spring correction factor is as follows: ξ=[β d -β0-sin(β d -β0)]+ΔΓ 2 +log 10 (1+ΔG)+e -ΔT Where ξ is the first spring correction coefficient, ΔΓ is the shear modulus error of the spring, and ΔT is the maximum standard temperature difference. The specific formula used to calculate the spring constant of each spring is as follows: K i =k i (1+ξ) Among them, K i Let be the spring constant of the spring connected to the i-th adjustable grid bar.

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

8. The design method of a spiral chute with adjustable grid bars based on slurry flow rate according to claim 1, characterized in that: The specific logic for verifying the deflection angle of the adjustable grid and the sorting performance of the spiral chute is as follows: Based on the structural parameters of the above design, the adjustable grid is 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 minimum and maximum slurry flow conditions. min ′、β max And compare it with the corresponding optimal grid deflection angle. and If the deflection angle check meets the requirements, then repeat steps S1-S6; The recovery rate of the target mineral particles in the concentrate belt is determined by the following: if the recovery rate of the spiral chute with adjustable grid is higher than that of the existing spiral chute, then the separation performance meets the design requirements; otherwise, repeat steps S1-S6. The designed adjustable grid deflection angle and spiral chute sorting performance both met the design requirements, and the design is now complete.

9. A spiral chute with adjustable grid bars based on slurry flow rate, characterized in that; The spiral chute with adjustable grid bars based on slurry flow rate is designed by the spiral chute design method with adjustable grid bars based on slurry flow rate as described in any one of claims 1-8.

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