Material crushing cavity structure and method for designing a multi-stage nested material crushing cavity structure
11628445 · 2023-04-18
Assignee
Inventors
- Gaipin Cai (Ganzhou, CN)
- Chunsheng Gao (Ganzhou, CN)
- Zhihong Jiang (Ganzhou, CN)
- Guohu Luo (Ganzhou, CN)
Cpc classification
International classification
B02C2/00
PERFORMING OPERATIONS; TRANSPORTING
B02C25/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The embodiments of the present invention provide a crushing cavity structure for the technical field of crushing cavities of cone crushing equipment. The crushing cavity structure comprises: a first crushing cavity structure for through-crushing an input material having a first material characteristic, the first crushing cavity structure has a first crushing cavity and a first lining plate structure that match the first material characteristic, and the first crushing cavity and the first lining plate structure form a first-stage material crushing channel; a second crushing cavity structure for through-crushing a first-stage material having a second material characteristic, the first-stage material is obtained by the input material passing through the first-stage material crushing channel, the second crushing cavity structure has a second crushing cavity and a second lining plate structure that match the second material characteristic, and the second crushing cavity and the second lining plate structure form a second-stage material crushing channel.
Claims
1. A material crushing cavity structure, comprising: a first crushing cavity structure for passing through an input material having a first material characteristic, the first crushing cavity structure has a first crushing cavity and a first lining plate structure that match the first material characteristic, and the first crushing cavity and the first lining plate structure form a first-stage material crushing channel, wherein, the first lining plate structure comprises a fixed cone lining plate and a moving cone lining plate, the working faces of the fixed cone lining plate and the moving cone lining plate are stepped curve faces, so that the first crushing cavity forms a first-stage laminating crushing cavity; a second crushing cavity structure for passing through a first-stage material having a second material characteristic, the first-stage material is obtained by the input material passing through the first-stage material crushing channel, the second crushing cavity structure has a second crushing cavity and a second lining plate structure that match the second material characteristic, and the second crushing cavity and the second lining plate structure form a second-stage material crushing channel, wherein, the second lining plate structure comprises a concave-convex lining plate structure formed by arranging concave-convex structures on the working faces of the fixed cone lining plate and the moving cone lining plate in the first crushing cavity, so that the second lining plate structure is nested in the first lining plate structure to form a second-stage laminating crushing cavity; wherein, the first-stage material crushing channel and the second-stage material crushing channel form a continuous material crushing channel.
2. The material crushing cavity structure of claim 1, further comprising: a third crushing cavity structure for passing through a second-stage material having a third material characteristic to obtain a crushed output material, the second-stage material is obtained by the first-stage material passing through the second-stage material crushing channel, the third crushing cavity structure has a third crushing cavity and a third lining plate structure that match the third material characteristic, and the third crushing cavity and the third lining plate structure form a third-stage material crushing channel; wherein, the third-stage material crushing channel and the continuous material crushing channel form a multi-stage continuous material crushing channel.
3. The material crushing cavity structure of claim 2, wherein, the second lining plate structure and the third lining plate structure are arranged with the first lining plate structure sequentially, and form a multi-stage nested crushing cavity structure together with the first lining plate structure, any one of the second crushing cavity and the third crushing cavity is different from the first crushing cavity in terms of the cavity size, and the second crushing cavity and the third crushing cavity are different from each other in terms of the cavity size.
4. The material crushing cavity structure of claim 3, wherein, the working faces of the fixed cone lining plate and the moving cone lining plate form an upper laminating crushing cavity, a middle laminating crushing cavity, and a lower laminating crushing cavity, the sizes of which are reduced sequentially, with respect to the position of the input material; the upper laminating crushing cavity, the middle laminating crushing cavity, and the lower laminating crushing cavity form the first crushing cavity.
5. The material crushing cavity structure of claim 4, wherein, the third lining plate structure comprises: concave wedge grooves arranged on a parallel working face of the moving cone lining plate relative to the fixed cone lining plate.
6. The material crushing cavity structure of claim 4, wherein, the concave-convex lining plate structure forms an upper nested second-stage laminating crushing cavity, a middle nested second-stage laminating crushing cavity, and a lower nested second-stage laminating crushing cavity, the sizes of which are reduced sequentially, corresponding to the upper laminating crushing cavity, the middle laminating crushing cavity, and the lower laminating crushing cavity; the upper nested second-stage laminating crushing cavity, the middle nested second-stage laminating crushing cavity, and the lower nested second-stage laminating crushing cavity form the second crushing cavity.
7. The material crushing cavity structure of claim 6, wherein, the concave-convex structure comprises: concave grooves, which extend along the generatrix of the conical surface of the fixed cone lining plate or the moving cone lining plate, and have constant groove width; convex cones, which are arranged in alternate with the concave grooves; wherein the groove depth of the concave grooves varies from deep to shallow with respect to the working faces of the convex cones along the displacement vector direction of the input material; wherein in the longitudinal cross section of a selected moving cone lining plate or fixed cone lining plate, the symmetrical central planes of the concave grooves are at a spiral angle with respect to the generatrix of the conical surface of the current lining plate, the rotation direction of the spiral angle is the same as the rotation direction of the moving cone lining plate; wherein the working faces of the convex cones are arranged in a spiral sector shape along the displacement vector direction of the input material.
8. A method for designing a multi-stage nested material crushing cavity structure, comprising the following steps: S1) selecting a first crushing cavity structure according to the material characteristics of an input material, wherein, the first crushing cavity structure has a first crushing cavity and a first lining plate structure, the first lining plate structure comprises a fixed cone lining plate and a moving cone lining plate, working faces of the fixed cone lining plate and the moving cone lining plate are stepped curve faces, so that the first crushing cavity forms a first-stage laminating crushing cavity; S2) selecting a second crushing cavity structure according to the material characteristics of a first-stage material obtained by the input material passing through the first crushing cavity structure, and nesting the second crushing cavity structure in the first crushing cavity structure to form a continuous material crushing channel, wherein, the second crushing cavity structure has a second lining plate structure, the second lining plate structure comprises a concave-convex lining plate structure formed by arranging concave-convex structures on the working faces of the fixed cone lining plate and the moving cone lining plate in the first crushing cavity, so that the second lining plate structure is nested in the first lining plate structure to form a second-stage laminating crushing cavity; S3) selecting a third crushing cavity structure according to the material characteristics of a second-stage material obtained by the first-stage material passing through the second crushing cavity structure, and forming a multi-stage continuous material crushing channel by the third crushing cavity structure, the first crushing cavity structure and the second crushing cavity structure.
9. The method of claim 8, wherein, the second crushing cavity structure has a second crushing cavity, and the operation of arranging the second crushing cavity structure in the first crushing cavity structure to form the continuous material crushing channel in the step S2) comprises: arranging a concave-convex structure on the working face of the first lining plate structure in the first crushing cavity structure, taking a part of the first lining plate structure arranged with the concave-convex structure as the second lining plate structure of the second crushing cavity structure and forming the second crushing cavity of the second crushing cavity structure, so that the second crushing cavity structure is nested in the first crushing cavity structure to form the continuous material crashing channel.
10. The method of claim 9, wherein, the third crushing cavity structure has a third crushing cavity and a third lining plate structure, and the operation of forming the multi-stage continuous material crushing channel by the third crushing cavity structure, the first crushing cavity structure and the second crushing cavity structure in the step S3) comprises: forming the third lining plate structure of the third crushing cavity structure and forming the third crushing cavity by arranging concave wedge grooves in the parallel working face of the moving cone lining plate of the first crushing cavity structure, so that the third crushing cavity structure, the first crushing cavity structure and the second crushing cavity structure form the multi-stage continuous material crushing channel.
Description
BRIEF DESCRIPTION OF DRAWINGS
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DESCRIPTION OF REFERENCE NUMBERS
(7) 1—fixed conical lining plate 11—second-stage laminating crushing cavity nested at the upper part of the fixed conical lining plate 12—second-stage laminating crushing cavity nested at the middle part of the fixed conical lining plate 13—second-stage laminating crushing cavity nested at the lower part of the fixed cone lining plate 2—moving cone lining plate 21—second-stage laminating crushing cavity nested at the upper part of the moving cone lining plate 22—second-stage laminating crushing cavity nested at the middle part of the moving cone lining plate 23—second-stage laminating crushing cavity nested at the lower part of the moving cone lining plate 24—third-stage laminating crushing cavity nested in the parallel area of the moving cone lining plate 31—upper area of the first-stage crushing cavity 32—middle area of the first-stage crushing cavity 33—lower area of the first-stage crushing cavity 4—parallel area
DETAILED DESCRIPTION OF THE EMBODIMENTS
(8) Hereunder some embodiments of the present invention will be detailed with reference to the accompanying drawings. It should be understood that the embodiments described here are only provided to describe and explain the present invention, but shall not be deemed as constituting any limitation to the present invention.
Embodiment 1
(9) The present invention provides a crushing cavity structure that is composed of crushing cavity structures different in size, shape and structure, and distribution position, which are combined according to specific requirements into a multi-stage nested laminating crushing geometric cavity shape. Thus, on one hand, all materials in different particle diameters are subject to laminating crushing; on the other hand, the crushing load is homogenized in the height direction of the crushing cavity, and thereby the crushing efficiency is improved and the service life of the lining plates is prolonged.
(10) A material crushing cavity structure, comprising:
(11) a material feed port configured to import an input material having a first material characteristic;
(12) a first crushing cavity structure connected to the material feed port and configured for through-crushing the input material, wherein the first crushing cavity structure has a first crushing cavity and a first lining plate structure that match the first material characteristic and form a first-stage material crushing channel;
a second crushing cavity structure for through-crushing a first-stage material having a second material characteristic, wherein the first-stage material is obtained by the input material passing through the first-stage material crushing channel, the second crushing cavity structure has a second crushing cavity and a second lining plate structure that match the second material characteristic and form a second-stage material crushing channel;
wherein, the first-stage material crushing channel and the second-stage material crushing channel form a continuous material crushing channel.
(1) Design Method of First-Stage Laminating Crushing Cavity
(13) The first lining plate structure of the first crushing cavity structure comprises a fixed cone lining plate 1 and a moving cone lining plate 2, and a first-stage laminating crushing cavity 3 and a parallel area 4 formed by the working faces of the fixed cone lining plate 1 and the moving cone lining plate 2.
(14) The first-stage laminating crushing cavity 3 is composed of an upper laminating crushing cavity 31, a middle laminating crushing cavity 32, and a lower laminating crushing cavity 33 formed between corresponding steps on the fixed cone lining plate 1 and the moving cone lining plate 2.
(15) The angles of engagement of the upper laminating crushing cavity 31, the middle laminating crushing cavity 32, and the lower laminating crushing cavity 33 shall meet the requirements for the laminating crushing cavity and the lining plate structure.
(16) (2) Design Method of Second-Stage Laminating Crushing Cavity Structure
(17) The regular conical working faces of the corresponding fixed cone lining plates and moving cone lining plates in different cavities of the first-stage crushing cavity are made into concave-convex conical surfaces. In the upper laminating crushing cavity 31, a second-stage laminating crushing cavity 11 is nested at the upper part of the fixed cone lining plate 1, and a second-stage laminating crushing cavity 21 is nested at the upper part of the moving cone lining plate 2. In the middle laminating crushing cavity 32, a second-stage laminating crushing cavity 12 is nested at the middle part of the fixed cone lining plate 1, and a second-stage laminating crushing cavity 22 is nested at the middle part of the moving cone lining plate 2. In the lower laminating crushing cavity 31, a second-stage laminating crushing cavity 13 is nested at the lower part of the fixed cone lining plate 1, and a second-stage laminating crushing cavity 23 is nested at the lower part of the moving cone lining plate 2.
(18) The concave-convex conical surface 21 of the moving cone lining plate 2 has concave grooves 211 convex conical faces 212, wherein the width of the concave grooves 211 is constant in the direction of the generatrix of the conical surface. The depth of the concave grooves 211 varies from deep to shallow in the direction of the generatrix from top to bottom (the position of the input material is at the top, with respect to the material displacement direction). The symmetrical central plane of the concave grooves 211 is at a spiral angle α to the generatrix in the same longitudinal cross section, and the rotation direction of the helical angle α is the same as the rotation direction of the moving cone lining plate in the crushing process.
(19) The convex conical faces between the grooves 211 in the conical surface 21 of the concave-convex moving cone lining plate are arranged in a spiral sector shape in the direction of the generatrix from top to bottom.
(20) The conical surface 11 of the concave-convex fixed cone lining plate also have grooves 211 and convex conical faces 212. The width and depth of the grooves and their tendency of variation, and the size and rotation direction of the helical angle of the grooves are consistent with those on the concave-convex conical surface of the moving cone lining plate 21.
(21) (3) Design Method of Third-Stage Wedge-Shaped Laminating Crushing Cavity Structure
(22) Several two-dimensional concave wedge grooves are uniformly distributed at an even angular interval on the working face of the moving cone lining plate 24 corresponding to the parallel area 4 (or material discharge port). The structure of the concave wedge groove consists of a linear wedge structure 241 in the direction of generatrix of the conical surface and an arc wedge structure 242 in the circumferential direction.
(23) The depth of the linear wedge structure 241 of the concave wedge groove in the direction of generatrix of the conical surface of the moving cone lining plate 24 is gradually reduced from top to bottom;
(24) the cross section of the arc wedge structure 242 of the concave wedge groove in the circumferential direction of the conical surface of the moving cone lining plate 24 consists of an outer arc section, a linear section, and an inner arc section. The depth of the arc wedge structure 242 is gradually reduced in the circumferential direction of the conical surface.
(4) Establishment of Multi-Scale Cohesive Particle Model of Irregularity Ore Based on 3D Scan
Step 1: construction of geometric multi-scale particle model of irregular ore
(25) Before the crushing, the ore is scanned by 3D laser scanning, and a NURBS three-dimensional curved face geometric template is constructed for individual irregular ore particles with Geomagic Studio;
(26) information of unit aggregates required for multi-scale model construction, such as the number, coordinates, and dimensions of the unit aggregates, etc., are obtained according to the particle shapes and particle diameters after the crushing, the 3D scanned NURBS curved face template is imported with a Particle Factory plugin, and a multi-scale geometric particle model of the irregular ore is reconstructed.
Step 2: Construction of mechanical multi-scale cohesion model of the ore
(27) The intrinsic parameters, contact parameters, and BPM cohesion parameters of the particle model are determined according to the mechanical parameters (e.g., hardness and toughness, etc.) of the ore acquired in crushing experiments. The normal stiffness, tangential stiffness, normal ultimate strength and tangential ultimate strength among the unit bodies in the model of individual ore particles are defined based on a BPM contact model.
(28) Step 3: A multi-scale particle group/pile model of ore in different shapes is established by means of the multi-shape API plugin of EDEM Particle Factory, according to the established model of individual irregular multi-scale ore particles.
(29) (5) Construction of Crushing Model and Simulation of Crushing Process
(30) Step 1: first-stage, second-stage, and third-stage crushing cavity structures are established, and a three-dimensional model of fixed cone lining plate and moving cone lining plate is established; a multi-stage crushing cavity model is established according to the oscillation angle of the moving cone and the dimensions of the material discharge port, and the multi-scale particle group/pile model of irregular ore is filled into the crushing cavity.
Step 2: a physical model of material crushing process is established according to the rotation speed of the moving cone, and two-way coupling is performed with EDEM and ADAMS, to simulate the crushing process of the material in the multi-stage crushing cavity.
Step 3: the contact behaviors among unit bodies and particles are handled with a Hertz contact method, and the deformation of the particles is judged according to the linear displacement and angular displacement of units at different scales.
Step 4: the stress state in the particle model is calculated through contact analysis and external load analysis, crushing is started with the particle model when the stress state meets the maximum tensile-stress criterion and Mohr-Coulomb criterion, and the crushing with the particle model is described with the stress on the bonds among the unit bodies.
(6) Establishment of a Material Size-Grade Distribution Model in the Crushing Cavity
Step 1: the influences of structural parameters of the crushing cavity (dimensions of the material feed port, dimensions of the material discharge port, and height of the crushing cavity), material size-grade distribution before crushing, rotation speed and oscillation angle of the moving cone, etc. on the size-grade distribution after crushing are analyzed.
Step 2: a size-grade distribution model in the crushing process is constructed with the following method:
1) The following size-grade mass balance model based on mass balance is utilized, i.e.:
P=(I−C)(I−BC).sup.−1f (1)
Where, P—discharged material size-grade distribution vector, f—fed material size-grade distribution vector, B—crushing function matrix, C—grading function matrix, which is a diagonal matrix, I—identity matrix;
2) Determination of Crushing Matrix
(31) The crushing matrix is a i×j matrix, where i represents the size grades of the mother material before crushing, and j represents the size grades of the child material after crushing. Each element in the crushing matrix is calculated with a continuous crushing function, and each element in the crushing functional matrix B can be determined according to formula (2), i.e.:
(32)
Where, m—average particle diameter (mm) of a material size grade in the size-grade distribution after crushing, n—average particle diameter (mm) of a material size grade in the size-grade distribution before crushing, b.sub.mn—a crushing matrix calculation function, which represents the distribution (%) of particles at size grade d.sub.n in the mother material in the size grade d.sub.m after crushing, d.sub.m—upper limit of a grading group in the child material, d.sub.m-1—lower limit of a grading group in the child material, d.sub.n—upper limit of a grading group in the mother material, d.sub.n-1—lower limit of a grading group in the mother material, φ(d.sub.m,d.sub.n)—a crushing accumulation function, which represents the percentage of particles at size grade d.sub.n in the mother material in the particles is smaller than d.sub.m in the child material after crushing;
3) Determination of Grading Matrix
(33) Supposing d.sub.1 represents the critical size that determines whether a unit particle is to be crushed, the critical size that determines whether the particle is to be crushed in the crusher is determined by the size b of the material discharge port, i.e., d.sub.1=s. Supposing d.sub.2 represents the critical size that determines whether a unit particle can be crushed completely, the critical size that determines whether the particle can be crushed completely in the crusher is determined by the width L of the material feed port, the particles between d.sub.1 and d.sub.2 enter into the crushing process according to the grading function C(d). Supposing the grading function is a quadratic function and the curve gradient at d.sub.2 is zero, the grading function may be expressed as:
(34)
(35) C(d) is a continuous grading function, but the material size-grade groups at specific height in the crushing cavity are discontinuous. Therefore, C*(d) may be used to represent the average value of the continuous function C(d) at granularity d. The following expression C*(d) can be derived from the above expression, i.e.:
(36)
(37) The continuous function C.sub.n (d) for material size grade between (d.sub.n, d.sub.n-1) may be expressed as:
(38)
4) Determination of Feed Material Size-Grade Vector f
(39) The mother material is screened into i size grades before crushing, and thereby a i×1 fed material size-grade vector is established, and each element in that vector is the proportion of a size grade of material in the mother material, i.e.:
f=[f.sub.1,f.sub.2,f.sub.3, . . . ,f.sub.m].sup.T (6)
5) Determination of Size-Grade Distribution Vector P of Discharged Material
(40) The size-grade distribution vector P after crushing is a j×1 vector, the crushed material is screened into j size grades, and the proportion of each size grade of material in the discharged material is the value of the corresponding element in the vector P.
(41) The elements in the matrices B and C are determined through calculation, then the size-grade distribution vector f of the fed material is substituted into the matrices, so that the size-grade distribution of the discharged material from the crushing cavity structure corresponding to the size-grade distribution of the fed material is described with vector P.
(42) (7) Structural and Dimensional Optimization of Multi-Stage Crushing Cavity
(43) Step 1: the composition of grading fractions at different height positions in the multi-stage crushing cavity is calculated with the crushing function P, based on the movement trajectory of the particles in the crushing process;
(44) Step 2: a target size grade of the discharged material after crushing is set;
(45) Step 3: the calculated size grade of the discharged material from the multi-stage crushing cavity is compared with the target size grade. If the calculated size grade of the discharged material doesn't reach the target size grade, the shape and structure, angle of engagement, and length dimension of the crushing cavities in the stages are adjusted on the basis of the size-grade distribution in the multi-stage crushing cavity from top to bottom, till the requirement is met.
(46) This embodiment has the following unique effects: (1) The upper laminating crushing cavity is nested in the form of a convex-concave conical surface structure, the laminating crushing effect of the upper crushing cavity can be enhanced at the feeding capacity (especially in the case of full-cavity material feeding), and materials in different particle diameters can be crushed efficiently; (2) The lower laminating crushing cavity is nested in the form of a multi-dimensional wedge-shaped groove structure, so that a material in large particle diameter can be fed easily into the wedge-shaped groove cavity, a favorable condition for effective crushing of a material in large particle diameter in the cavity is created. Thereby the crushing load and wearing in the parallel area can be reduced, and the size grade of the discharged material can be homogenized; (3) With nested multi-gradient laminating crushing geometric cavity and lining plate structure, the material crushing is changed from simple crushing to crushing, chopping, and shearing in combination, and the effective utilization of crushing energy is improved. Moreover, the crushing load and the wearing rate of the lining plate are homogenized in the height direction of the crushing cavity, the service life of the lining plate is effectively prolonged, and the consistency of the crushing cavity shape is maintained; (4) With an analytical method that incorporated crushing process simulation and crushing size-grade modeling, the structure and dimensions of the multi-stage crushing cavity are optimized, the rationality of the multi-stage crushing cavity structure can be improved remarkably, and the crushing cavity design is transited from empirical cut-and-trial design to accurate quantitative analysis and design.
Embodiment 2
(47) Based on embodiment 1, furthermore: 1. The steps of design of the first-stage crushing cavity as shown in
(1) Crushing Experiment Analysis The material in the experiment is copper ore, with Platts hardness coefficient within a range of 14˜20, and the size grades of the fed material are shown in Table 1.
(48) TABLE-US-00001 TABLE 1 Size-Grade Distribution of Fed Copper Ore Particle diameter (mm) 45~60 30~45 20~30 −20 Σ Weight (kg) 18.5 32.2 13.7 27.5 91.9 Percent (%) 20.1 35.0 14.9 29.9 99.9
(49) Through repeated sampling after crushing with a PYD1650 cone crusher, the average values of the size grades are shown in Table 2.
(50) TABLE-US-00002 TABLE 2 Size-Grade Distribution of Crushed Copper Ore Particle diameter (mm) +30 20~30 10~20 −10 Σ Weight (kg) 42.0 18.3 11.0 1.8 73.1 Percent (%) 57.5 25.0 15.0 2.5 100
(2) Derivation of Accumulative Crushing Function
(51) Through size-grade data analysis and multi-parameter fitting after the crushing with PYD1650 cone crusher, the tendency of change from the particle diameter t.sub.2 before crushing to different particle diameters t.sub.5, t.sub.10, t.sub.28 and t.sub.46 after crushing is obtained respectively, i.e.:
(52)
(53) Where, t.sub.n is the proportion of particles smaller than one n.sup.th of the overall particle size of the mother material in the material, and t.sub.2 is the proportion of crushed material in particle diameter smaller than half of the particle diameter of the ore before crushing in the ore. n=5, 10, 28 and 46 according to the screening requirement.
(54) The values of t.sub.5, t.sub.10, t.sub.28 and t.sub.46 in the child materials when t.sub.2 is any value in the mother material can be calculated with formula (7). Based on the production experience, t.sub.2 is determined as 60, 50 and 40 respectively, and is substituted into the above formula, and the values of t.sub.5, t.sub.10, t.sub.28 and t.sub.46 are calculated respectively; the relation between t.sub.2 and t.sub.n is represented in a tabular form, i.e., an expression of accumulative crushing function, as shown in Table 3.
(55) TABLE-US-00003 TABLE 3 Accumulative Crushing Function Derived from Experimental Data of Crushing Proportion of screenings in mother material Proportion of screenings in child material (%) t.sub.2 (%) t.sub.5 (0.2) t.sub.10 (0.1) t.sub.28 (0.036) t.sub.46 (0.022) 40 11.5663 9.5643 4.0243 1.7957 50 13.7899 7.8663 3.5406 1.3168 60 22.9142 13.6321 7.8959 3.0920
(56) The expressions of the accumulative crushing function when the proportions of particles t.sub.2 in the mother material are 40%, 50% and 60% are obtained with a multi-parameter fitting method, as represented by formula (8), formula (9) and formula (10):
y==−4430.4414k.sup.2+152.1523k−1.1397 (8)
y=−131.2205k.sup.2+96.6848k−0.3263 (9)
y=−215.1213k.sup.2+151.7548k+1.0862 (10)
(57) Wherein, formula (8)—accumulative crushing function when the proportion of the particles t.sub.2 is 40% in the mother material; formula (9)—accumulative crushing function when the proportion of the particles t.sub.2 is 50% in the mother material; formula (10)—accumulative crushing function when the proportion of the particles t.sub.2 is 60% in the mother material.
(58) Suppose the ratio of the overall geometric size x of particles of crushed child material at a size grade to the overall geometric size Y of the particles of the mother material is defined as K, i.e., K=x/Y; when the overall geometric size of the particles of the child material is x=1, K=1/n.
(59) In the above three formulae, y represents the proportion of the screenings, and k represents the ratio of the particle diameter of the child material to the particle diameter of the mother material. After the accumulative crushing function is obtained, the corresponding proportion of the screenings for any value of K (i.e., K is any value) can be obtained. It may be expressed by φ(d.sub.m,d.sub.n) as:
(60)
(2) Derivation of Crushing Matrix
(61) The mother material is screened into four size grades −20 mm, 20 mm˜30 mm, 30 mm˜45 mm, and 45 mm˜60 mm according to formula (12) on the basis of the actual situation of the experiment, and the crushed child material is screened into four size grades +15 mm, 10˜15 mm, 5˜10 mm, and −5 mm According to such size grading, the crushing matrix B is a 4×4 matrix, the rows of the matrix corresponding to the size grades of the mother material is expressed as j, and, starting from the first row, the rows correspond to −20 mm, 20 mm˜30 mm, 30 mm˜45 mm, and 45 mm˜60 mm respectively. The columns of the matrix corresponding to the size grades of the child material are expressed as i, and, starting from the first column, the columns correspond to +15 mm, 10˜15 mm, 5˜10 mm, and −5 mm respectively.
(62) The accumulative crushing function is d.sub.m/d′.sub.n, where d.sub.m is the upper limit of a size-grade group in the child material; d′.sub.n is the geometric average diameter of size-grade group n (i.e., d′.sub.n=√{square root over (d.sub.nd.sub.n-1)}, d.sub.n is the upper limit of particle diameter of the size-grade group in the mother material, d.sub.n-1 is the lower limit of particle diameter of the size-grade group in the mother material).
(63) According to the above definition, the d.sub.m/d.sub.n corresponding to each element in the crushing matrix B can be calculated, and the calculation results of i/j are as follows:
(64)
(65) Since the value t.sub.2 in the mother material tends to be 50%, the value is substituted into the accumulative crushing function formula (12) to calculate the elements in the crushing matrix B sequentially. It is seen from the average particle diameters of the size grades of the mother material and the child material: the average particle diameter of each size grade of the child material is smaller than the average particle diameter of each size grade of the mother material. Therefore, each element in the crushing matrix is applicable to the situation of m<n, and the element b.sub.mn in the crushing matrix B can be calculated with i/j, i.e.:
(66)
(67) The value i/j is substituted into the formula (12), and then the obtained result φ(d.sub.m,d.sub.n) is calculated in the formula (14), to obtain the values of the elements in the matrix B. Thus, the crushing matrix B may be expressed as:
(68)
(3) Derivation of Size Grading Matrix
(69) According to the dimension d.sub.1=60 mm of the material feed port and the dimension d.sub.2=8 mm of the material discharge port, in view that the mother material is graded into 0˜20 mm, 20˜30 mm, 30˜45 mm, and 45˜60 mm, in the calculation, 0, 20, 30, 45 and 60 are substituted into the formula (4), then:
(70)
(71) The above calculation results are substituted into the formula
(72)
then:
(73)
(74) Therefore, the size grading matrix C is:
(75)
(76) According to the Table 1, the size-grade distribution function of the fed material may be expressed as:
f=[0.201 0.35 0.149 0.299] (17)
Therefore, by substituting the formulae (15), (16) and (17) and identity matrix I into the formula (1), a size-grade distribution model of the discharged material in the case that the diameter of the material discharge port of the PYD1650 cone crusher is 8 mm and the maximum granularity of fed material is 60 mm can be obtained. 7. Simulation of crushing of irregular particles in a multi-stage crushing cavity through the following steps, as shown in
(77) The width of the granularity controller of a pre-grinding tester is set to 3 mm, and the length of the granularity controller is set to 20 mm; the result obtained through calculation with the size-grade distribution model of discharged material and result obtained in the pre-grinding experiment are shown in Table 4.
(78) TABLE-US-00004 TABLE 4 Comparison between Calculation Result and Experimental Result of Granularity of Discharged Material +2.362 mm 0.701~2.362 mm 0.254~0.701 mm −0.254 mm Experi- Experi- Experi- Experi- Experi- mental Calculated Relative mental Calculated Relative mental Calculated Relative mental Calculated Relative mental value value error value value error value value error value value error group (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) (%) Scheme 1 36.3 36.8 1.4 38.7 34.2 11.6 8.9 10.0 12.3 16.1 15.0 6.8 Scheme 2 35.6 36.8 3.4 41.1 38.9 5.4 10.2 10.1 1.0 13.1 11.6 11.5 Scheme 3 39.6 41.7 5.3 37.3 34.1 8.6 10.0 9.9 1.0 13.1 11.5 12.2
(79) It is seen from the above table: the calculation result and the experimental result match each other well for the size grades corresponding to most experimental groups; but the fluctuation of relative errors is severe for the size grades corresponding to some experimental groups.
(80) The research findings described above can set a basis for establishment of size-grade distribution model of crushed particle groups and multi-parameter crushing energy consumption analysis of relevant particle groups in the project.
(81) In the aspect of efficient crushing performance study, efficient crushing cavity design for crushers can be carried out with a multi-objective optimization method, mainly employing crushing yield and size reduction ratio as optimization objectives and employing parameters such as ore hardness, granularity before/after crushing, and structure of crushing cavity, etc. as constraints. Compared with ordinary crushing cavities, by utilizing the optimized crushing cavity, the proportion of particles at satisfactory granularity in the crushed product can be increased by 10% or more, the crushing yield can be improved by 20%˜40% or more, and the service life of the lining plate can be improved by 1˜2 times. Therefore, the crushing cavity optimization and modeling and the solution method provide a reference for this technique.
(82) While some preferred embodiments of the present invention are described above with reference to the accompanying drawings, the embodiments of the present invention are not limited to the details in those preferred embodiments. Various simple modifications and variations be made to the technical schemes of the embodiments of the present invention without departing from the technical concept of the embodiments of the present invention. However, all these simple modifications and variations shall be deemed as falling in the scope of protection of the embodiments of the present invention.
(83) In addition, it should be noted that the specific technical features described in above embodiments may be combined in any appropriate form, provided that there is no conflict. To avoid unnecessary iteration, such possible combinations are not described here in the present invention.
(84) Those skilled in the art can understand that all or a part of the steps constituting the method in the above-mentioned embodiments can be implemented by instructing relevant hardware with a program, which is stored in a storage medium and includes a number of instructions to instruct a single-chip microcomputer, a chipset, or a processor, etc. to execute all or a part of the steps of the method described in the embodiments of the present application. The above-mentioned storage medium may include: U-disk, removable hard disk, Read-Only Memory (ROM), Random Access Memory (RAM), diskette, or CD-ROM, or a similar medium that can store program codes.
(85) Moreover, different embodiments of the present invention may be combined freely as required, as long as the combinations don't deviate from the ideal and spirit of the embodiments of the present invention. However, such combinations shall also be deemed as falling in the scope disclosed by the embodiments of the present invention.