Fine-screening-free method and system for regulating grain composition of manufactured sand

Abstract

Disclosed are a fine-screening-free method and system for regulating grain composition of manufactured sand. The regulation method comprises: step (1), determining basic parameters; step (2), measuring the actual yield: measuring the discharge amount of materials of each size fraction among various grades of materials per unit time; step (3), calculating and determining an extraction ratio and a return ratio: comprehensively calculating on the basis of the determined number of size fractions, the number of grades, and the measured discharge amount of materials of each size fraction per unit time, to determine the extraction ratio and the return ratio; and step (4), controlling the discharge amount of a discharge port: on the basis of the determined extraction ratio and return ratio, generating a control instruction for a discharge and return control unit corresponding to each material, and controlling the discharge and return control unit to separate materials required by each grade and excess materials on the basis of the ratios determined in step (3). According to the method, accurate preset grain composition is achieved without fine screening of crushed materials.

Description

A fine screening-free machine-made sand particle grading adjustment method and system Technical Field

[0001] The present invention relates to machine-made sand, and in particular to a particle grading technology for machine-made sand. Background Art

[0002] The production process of manufactured sand is the process of mechanically crushing gravel (particle size > 4.75mm) into sand (particle size < 4.75mm). In production practice, the performance of concrete made from manufactured sand with the same content but different gradations varies greatly. Therefore, national standards have strict requirements for the particle gradation of finished manufactured sand for construction (for example, the content of particles with a particle size range of 1.18-2.36mm must be 30-35%;

[0003] Typically, the crushing process for manufactured sand consists of two steps: crushing and air separation. After entering the air separation system, the crushed material is divided into several grades based on the horizontal distance it moves under the influence of wind. Materials from different grades are then transported out of the air separation system through their respective discharge ports, as described in patent application publication number JP2003175367A. However, this classification method is imprecise, with no clear boundaries between grades. For example, coarse material may contain a small amount of mid-grade material, and mid-grade material may be mixed with fine material. Directly blending the materials separated by this classification method would not yield an accurate and controllable particle size distribution.

[0004] To improve precision, existing technologies for controlling the particle size distribution of manufactured sand typically adjust the crushing system's main current and feed rate to adjust particle size. For example, increasing the main current typically results in a decrease in coarse material and an increase in fine material. However, this method has the disadvantage of only controlling the average coarseness and fineness, not the particle size distribution.

[0005] Summary of the Invention

[0006] In view of the problem that the existing machine-made sand particle grading is difficult to control, the purpose of the present invention is to provide a machine-made sand particle grading adjustment method that does not require fine screening. This adjustment method controls the discharge amount from the discharge port, and can correctly combine the amount of materials at different levels without changing the grading of the crushed material, so that the particle grading of the finished machine-made sand meets the preset requirements; and on this basis, provides a machine-made sand particle grading adjustment system that does not require fine screening.

[0007] In order to achieve the above-mentioned object, the present invention provides a method for adjusting the particle gradation of machine-made sand without fine screening, comprising:

[0008] Step (1), determine basic parameters;

[0009] Based on the number n of particle sizes of the finished machine-made sand, the number of gears n equal to it is determined, and the ratio between the particle sizes in the finished machine-made sand is determined according to the requirements of the construction industry for the particle grading of machine-made sand.

[0010] Step (2), measuring the output;

[0011] Measure the discharge amount of each grade of material per unit time in each gear;

[0012] Step (3), calculating and determining the take-out ratio and return ratio;

[0013] Based on the number of particle sizes and the number of gears determined in step (1), and the discharge volume of each particle size per unit time measured in step (2), a comprehensive calculation is performed to determine the take-in ratio and the return ratio;

[0014] Step (4), regulating the discharge amount of the discharge port;

[0015] According to the take-in ratio and return ratio determined in step (3), the control instructions of the discharge and return control unit corresponding to each material are generated, and the discharge and return control unit is controlled to separate the required materials and excess materials of each gear according to the ratio in the third step.

[0016] In some examples of the present invention, in step (1), a corresponding finished sand particle gradation data model is constructed based on the mass percentage of each particle size for the required finished sand particle gradation.

[0017] In some examples of the present invention, in step (2), a corresponding discharge quantity data model is constructed for the discharge quantity of each particle size material at each gear.

[0018] In some embodiments of the present invention, in step (3), a usage ratio model is constructed based on the relationship between the number of particle gradations of the finished sand and the discharge amount of materials of each particle size, and the usage ratio model is converted into a corresponding matrix equation;

[0019] Next, for the conversion matrix equation, the utilization ratio and return ratio of each gear are calculated based on the number of particle sizes and the number of gears determined in step (1) and the discharge amount of each particle size material per unit time measured in step (2).

[0020] In some embodiments of the present invention, the excess material separated in step (4) is returned to the original material system, and steps (2) to (4) are repeated.

[0021] In order to achieve the above-mentioned object, the present invention provides a fine screening-free machine-made sand particle grading adjustment system, comprising:

[0022] A finished sand particle grading module, which determines the number of particle sizes and the number of equal gears of the finished machine-made sand and generates a finished sand particle grading data model accordingly;

[0023] The discharge amount measurement module is connected to the data of the automatic particle size detection instrument, which can measure the discharge amount of each particle size material in each gear per unit time and generate a discharge amount data model;

[0024] A ratio calculation module, which exchanges data with the finished sand particle grading module and the discharge quantity measurement module, and calculates and determines the take-in ratio and the return ratio;

[0025] A separation control module, which interacts with the proportion calculation module data and controls the connection of the discharge and return control unit. The separation control module can form control instructions based on the take ratio and return ratio calculated by the proportion calculation module to control the discharge and return control unit to separate the required materials and excess materials of each gear in proportion.

[0026] In some examples of the present invention, the finished sand particle grading data model generated by the finished sand particle grading module is a matrix data model constructed based on the mass percentage of each particle size.

[0027] In some examples of the present invention, the discharge quantity data model generated by the discharge quantity measurement module is a matrix data model constructed based on the discharge quantity of each particle size material at each gear.

[0028] The fine screening-free machine-made sand particle gradation adjustment solution provided by the present invention can achieve accurate preset particle gradation without fine screening of the crushed material. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention is further described below with reference to the accompanying drawings and specific embodiments.

[0030] FIG1 is a flow chart illustrating the process of adjusting the particle size distribution of machine-made sand without fine screening in the present invention;

[0031] FIG2 is a structural principle diagram of the material discharging and returning control unit in the present invention. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0033] Name explanation:

[0034] Machine-made sand: Made from rock, pebbles, mine waste, or tailings, it undergoes soil removal and mechanical crushing, shaping, screening, and powder control. The sand meets the required gradation, shape, and stone powder content, and has a particle size of less than 4.75mm. Machine-made sand is a key raw material for concrete.

[0035] Particle size: The particle size range of manufactured sand; according to national standards, there are strict upper and lower limits, such as: [2.36mm, 4.75mm].

[0036] Gear: The location where the crushed material falls due to the different horizontal movements under the action of wind. Usually three or four gears can be set. The material in each gear does not correspond to a specific particle size, that is, a gear may contain sand of multiple particle sizes.

[0037] Particle gradation: The percentage of particles of each size in the total amount of manufactured sand.

[0038] In response to the problem that the existing machine-made sand particle grading is difficult to control, the present invention provides a machine-made sand particle grading adjustment scheme that does not require fine screening. This scheme innovatively adopts the method of controlling the discharge amount at the discharge port to achieve machine-made sand particle grading adjustment that does not require fine screening. This scheme can correctly combine the amount of materials at different gears without changing the grading of the crushed material, so that the particle grading of the finished machine-made sand meets the preset requirements.

[0039] Specifically, the fine screening-free machine-made sand particle grading adjustment solution provided by the present invention is mainly composed of the following steps:

[0040] Step (1), determine basic parameters;

[0041] Based on the number of particle sizes n in the finished manufactured sand, the number of gears n is determined to be equal to it. The ratios between the particle sizes in the finished manufactured sand are determined according to the requirements of the construction industry for the particle size distribution of manufactured sand. At the same time, a corresponding finished sand particle size distribution data model is constructed based on this.

[0042] Step (2), measuring the output;

[0043] Measure the discharge amount of each grade of material per unit time in each gear;

[0044] Step (3), calculating and determining the take-out ratio and return ratio;

[0045] Based on the number of particle sizes and the number of gears determined in step (1), and the discharge volume of each particle size per unit time measured in step (2), a comprehensive calculation is performed to determine the take-in ratio and the return ratio;

[0046] Step (4), regulating the discharge amount of the discharge port;

[0047] According to the take-in ratio and return ratio determined in step (3), the control instructions of the discharge and return control unit corresponding to each material are generated, and the discharge and return control unit is controlled to separate the required materials and excess materials of each gear according to the ratio in the third step.

[0048] With respect to the method for adjusting the particle gradation of machine-made sand without fine screening provided by the present invention, the implementation process thereof is described in detail below.

[0049] The implementation process of the method for adjusting the particle size distribution of machine-made sand without fine screening is as follows, see Figure 1:

[0050] The first step is to determine the basic parameters.

[0051] In this step, the number n of particle sizes of the finished machine-made sand is determined, and the number n of gears equal to it is determined accordingly, that is, the number of particle sizes must be consistent with the number of gears.

[0052] For example, the number of particle sizes here is usually between 2 and 7, and the specific value corresponds to the system energy consumption and quality control: the larger the number of particle sizes, the more accurate the control of the particle grading of the finished machine-made sand, and the greater the system power and energy consumption; if the number of particle sizes is too small, although the system energy consumption is small, the particle grading of the finished sand is prone to discontinuity, and the concrete made with such finished sand is prone to segregation.

[0053] Based on the confirmed number of particle sizes n and the number of gears n, the required finished sand particle grading is further set according to actual production. The mass percentage of each particle size is arranged in a column from top to bottom in order of particle size from small to large to form a column vector, represented by b, thereby forming a finished sand particle grading data model.

[0054] in:

[0055] Or it can be expressed as b=[b1 b2 … b n ] T ;

[0056] Where, n is the number of particle sizes;

[0057] b i (1≤i≤n)——the proportion of material of the i-th particle size in the finished sand (%);

[0058] T - transpose symbol.

[0059] The second step is to measure the output.

[0060] This step is based on the automatic particle size detection instrument to measure the discharge amount of each particle size material in each gear per unit time.

[0061] The automated particle size detection instrument in this solution uses an electronic balance to measure the total mass of the material discharged at a specific level over a specified period of time. It also uses a high-speed camera to capture images of the falling material and analyze the proportions of particles within each size range. Combining these two methods, the mass of particles within each size range is then calculated. Compared to traditional screening methods, this solution reduces the influence of human factors and improves testing speed and accuracy.

[0062] According to the measured data, for each gear, the discharge volume of each particle size material is arranged from top to bottom in the order from small to large, forming a column vector; the column vectors of each gear are arranged from left to right in the order from coarse to fine materials in the gear, forming a matrix, represented by A, which serves as the discharge volume data model.

[0063] in:

[0064] Where A ij (1≤i≤n, 1≤j≤n)——The measured discharge volume of the i-th particle size in the j-th gear (unit: t / h, i.e., tons / hour).

[0065] The third step is to calculate the material usage ratio and return ratio of each gear.

[0066] In this step, a proportional model is first constructed based on the proportional relationship between the number of finished sand particle sizes and the discharge volume of each particle size, and the proportional model is converted into a corresponding matrix equation;

[0067] Next, for the conversion matrix equation, based on the number of particle sizes and the number of gears determined in step one, and the discharge volume of each particle size per unit time measured in step two, the utilization ratio and return ratio of each gear are calculated to determine.

[0068] Specifically, in this step, based on the data model determined in step 1 and step 2, a usage ratio model is constructed. The usage ratio model is specifically constructed by the following matrix equation: Ax = b (1)

[0069] Among them, b is the column vector formed in step 1; A is the matrix formed in step 2; and column vector x is the utilization ratio of each discharge port.

[0070] The utilization ratio model constructed based on this can accurately express the utilization ratio of each gear, and also facilitates subsequent efficient calculations.

[0071] Based on this, for the matrix equation (1), and combined with the column vector b formed in step 1 and the matrix A formed in step 2, the column vector x of the material extraction ratio of each discharge port can be calculated:

[0072] Where: x=[x1 x2 … x n ] T ;

[0073] Where x i (1≤i≤n)——In order to achieve the set particle gradation, the amount of material that needs to be taken out from the i-th gear and blended into the finished sand accounts for the proportion of the output of that gear.

[0074] This step also provides an alternative solution, based on the column vector b and the matrix A, to transform the matrix equation (1) into equation (2):

[0075] On this basis, we combine the column vector b formed in step 1 and the matrix A formed in step 2 to further solve equation (2) to obtain x1, x2, ... x n The value of , and press x1 to x n Arrange them from top to bottom to form a column vector x.

[0076] Among them, the actual utilization ratio is determined and represented by the column vector x′.

[0077] The maximum value of each element in the column vector x is x max , that is, x max =max{x1,x2…,x n} (3)

[0078] The actual usage ratio can be expressed as:

[0079] Where x i (1≤i≤n)——The proportion of material of the i-th particle size in each finished sand product required to achieve the set particle size distribution and maximize the output.

[0080] In this solution, by adding the calculation of formulas (3) and (4) on the basis of solving equations (1) or (2), the maximum value of each element in the column vector x′ (i.e., the utilization ratio of each gear) can be exactly 1. This ensures that all materials in a certain gear are fully utilized (no return material), and that materials in other gears are partially utilized and partially returned, thereby maximizing the utilization rate of materials in each gear.

[0081] This can avoid the problem that the maximum element of the column vector x obtained by equation (1) or (2) alone may be greater than 1 or less than 1; when the maximum element of the column vector x is greater than 1, it means that the utilization ratio of some gears exceeds 100%, which is not in line with the actual situation; and when the maximum element of the column vector x is less than 1, it means that the utilization rate is not maximized.

[0082] This step first calculates the excess material ratio of each gear based on the data model determined in steps 1 and 2. The excess material ratio of each gear can be represented by r, where: r = [1 1 … 1] T -x′ (5)

[0083] Formula (5) is constructed here based on the principle that the sum of the take-in ratio and the return ratio in each gear is 1, which facilitates efficient calculation when n>3.

[0084] Furthermore, the excess material determined in this step can be returned to the main machine via a belt for secondary crushing, or can be exported to the winnowing system through a chute for storage.

[0085] The fourth step is to separate the used material from the remaining material, and the remaining material is returned to the main machine or stored.

[0086] This step generates control instructions for the discharge and return control unit corresponding to each material based on the take-in ratio and return ratio determined in step three, and controls the discharge and return control unit to separate the required materials and excess materials of each gear according to the ratio in the third step.

[0087] Specifically, in this step, the opening and closing angles of the baffles at the outlets of each gear are adjusted to separate the required materials and excess materials at each gear according to the ratio in the third step.

[0088] Extensive testing has confirmed that the take rate is generally proportional to the angle at which the adjustable damper in the discharge and return control unit opens relative to the discharge port. For example, when the adjustable damper is open at a 30° angle relative to the discharge port, the take rate is 33% and the return rate is 67%. Furthermore, when the adjustable damper is open at a 90° angle relative to the discharge port, the take rate is 100% and the return rate is 0%.

[0089] If in this step the excess material is returned to the main machine through the belt for secondary crushing, then jump to step 2 for continuous cycle calculation and adjustment.

[0090] Since the material from each gear returns to the crushing system, the subsequent material gradation from the crusher will change. By looping through steps 2 to 4, the particle size distribution of the finished machine-made sand can be automatically adjusted in real time based on the changes in the material gradation after crushing.

[0091] Based on the above implementation plan, it can be seen that the fine screening-free machine-made sand particle grading adjustment scheme provided by the present invention uses the solution of matrix equations to effectively calculate and determine the material utilization ratio of different gears. On this basis, the material utilization ratio of each gear is controlled by real-time monitoring of the material grading of each gear and adjustment of the gear outlet angle.

[0092] Regarding the fine screening-free machine-made sand particle grading adjustment scheme provided by the present invention, the technical features and functions of this scheme are further illustrated below through corresponding examples.

[0093] In this example, a corresponding machine-made sand particle grading adjustment system is constructed based on the aforementioned fine screening-free machine-made sand particle grading adjustment scheme to assist in implementing the scheme of the present invention.

[0094] As an example, the machine-made sand particle grading adjustment system here is composed of a corresponding computing server (such as computing) and a machine-made sand particle grading adjustment software program running on the computing server.

[0095] The machine-made sand particle grading adjustment software program is composed of a finished sand particle grading module, a discharge quantity measurement module, a ratio calculation module, and a separation control module.

[0096] The finished sand particle grading module in this system can determine the number of particle sizes and the number of equal gears of the finished machine-made sand, and generate a finished sand particle grading data model based on this.

[0097] In some embodiments, the finished sand particle grading module is configured to execute a specific solution of the aforementioned step 1 to implement a matrix data model constructed based on the mass percentage of each particle size.

[0098] The discharge quantity measurement module in this system is connected to the data of the automatic particle size detection instrument, which can measure the discharge quantity of each particle size material in each gear per unit time and generate a discharge quantity data model.

[0099] In some embodiments, the discharge amount measurement module is configured to execute the specific solution of the aforementioned step 2 to implement a matrix data model constructed based on the discharge amount of each particle size material at each gear.

[0100] The ratio calculation module in this system interacts with the finished sand particle grading module and the discharge quantity measurement module to calculate and determine the take-in ratio and return ratio.

[0101] In some embodiments, the ratio calculation module is configured to execute the specific solution of the aforementioned step three to calculate and determine the take ratio and the return ratio.

[0102] The separation control module in this system interacts with the proportional calculation module in data, and controls the connection of the discharge and return control unit. The separation control module can form control instructions based on the take ratio and return ratio calculated by the proportional calculation module to control the discharge and return control unit to separate the required materials and excess materials of each gear in proportion.

[0103] In some embodiments, the separation control module is configured to execute the specific solution of the aforementioned step 4 to achieve separation control of the used material and the remaining material.

[0104] Refer to FIG2 , which shows a structural example diagram of a discharge and return control unit implemented in conjunction with the machine-made sand particle grading adjustment system in this example.

[0105] The discharging and returning control unit is mainly composed of an inlet 1, a hopper 2, a discharging port 3, an angle-adjustable baffle 4, an overflow channel 5 and an overflow channel outlet 6.

[0106] The interior of the hopper 2 is hollow, with a corresponding feed port 1 on the top and a discharge port 3 on the bottom. At the same time, an overflow channel 5 is provided on the middle side wall, which is connected to the inner cavity of the hopper 2 and has an overflow channel outlet 6 on the top.

[0107] On this basis, a corresponding angle-adjustable baffle 4 is further provided at the discharge port 3 of the hopper 2. The angle-adjustable baffle 4 can swing relative to the discharge port 3, and the opening size of the discharge port 3 can be adjusted according to the swing angle. Specifically, the angle-adjustable baffle 4 can completely cover the discharge port 3, or completely open the discharge port 3, and can be continuously adjusted between these two states.

[0108] The specific structure and arrangement of the angle-adjustable baffle 4 are not limited here and can be determined according to actual needs.

[0109] When the discharging and returning control unit of such a structure cooperates with the machine-made sand particle grading adjustment system, a discharging and returning control unit is respectively configured for each gear material port after air selection. The discharging and returning control unit configured for each gear material port has an inlet 1 connected to each gear material port, and the overflow channel outlet 6 cooperates with the return material conveyor belt to connect to the main machine; and the angle-adjustable baffle 4 is controlled by the machine-made sand particle grading adjustment system.

[0110] In this way, the machine-made sand particle gradation adjustment system can continuously change the opening degree of the discharge port 3 between 100% and 0 by adjusting the swing angle of the angle-adjustable baffle 4 relative to the discharge port 3.

[0111] Based on this, the machine-made sand particle grading adjustment system formed in this example can accurately adjust the machine-made sand particle grading without fine screening. The specific process is as follows:

[0112] As shown in Figure 2, the crushed material is separated into several grades according to particle size through air separation. The crushed and air-separated material in each grade enters the corresponding discharge and return control unit. The corresponding material enters hopper 2 from inlet 1 and falls freely, and is discharged from outlet 3 at the bottom. During the discharge process, due to the restriction of angle-adjustable baffle 4, the amount of material discharged from outlet 3 per unit time is less than that entering from inlet 1. As the material in hopper 2 accumulates, once it exceeds the overflow channel 5, the excess material is discharged from overflow channel outlet 6 and conveyed to the main machine by a belt.

[0113] During this process, the machine-made sand particle grading adjustment system uses real-time monitoring of the material grading at each gear and adjustment of the gear outlet angle to control the material usage ratio at each gear.

[0114] The following is an explanation with reference to specific application examples.

[0115] Example 1

[0116] In this embodiment, the ratio of the two particle sizes in the finished sand (n=2) needs to be controlled as follows:

[0117] The discharge port of the air separation equipment has two gears, each gear is equipped with a discharge and return control unit, and the measured output of the material at each gear is as follows

[0118] Based on this, the process of adjusting the particle size distribution of manufactured sand based on the manufactured sand particle size distribution adjustment system in this embodiment is as follows:

[0119] The first step is to determine n = 2 based on the number of particle sizes in the finished sand. The finished sand particle grading module in the system calculates b = [50 50] based on the proportion of this particle size in the finished sand. T ;

[0120] In the second step, the output measurement module in the system constructs the matrix A according to the measured output, and obtains

[0121] The third step is that the proportion calculation module in the system solves the matrix equation Ax=b according to the b determined by the finished sand particle grading module and the matrix A constructed by the discharge measurement module.

[0122] The solution is

[0123] Since the maximum value of each element in the column vector x is x max is 5 / 6, so

[0124] Based on this, the ratio of gear A to gear B is determined to be 0.75:1. That is, in gear A, 75% is used and 25% is returned to the host or stored; in gear B, 100% is used.

[0125] In the fourth step, the separation control module in the system determines that the angle-adjustable baffle in the discharge and return control unit configured in the control gear A is opened 67.5° relative to the discharge port; at the same time, the angle-adjustable baffle in the discharge and return control unit configured in the control gear B is opened 90° relative to the discharge port.

[0126] Example 2

[0127] Known: The proportion of five particle sizes (n=5) in the finished sand needs to be controlled as follows

[0128] The discharge port of the air separation equipment has five gears, each gear is equipped with a discharge and return control unit, and the measured output of the material at each gear is as follows

[0129] Based on this, the process of adjusting the particle size distribution of manufactured sand based on the manufactured sand particle size distribution adjustment system in this embodiment is as follows:

[0130] The first step is to determine n = 2 based on the number of particle sizes in the finished sand. The finished sand particle grading module in the system calculates b = [4 18 28 32.5 17.5] based on the proportion of this particle size in the finished sand. T

[0131] In the second step, the output measurement module in the system constructs the matrix A according to the measured output, and obtains

[0132] The third step is that the proportion calculation module in the system solves the matrix equation Ax=b according to the b determined by the finished sand particle grading module and the matrix A constructed by the discharge measurement module.

[0133] Solving for x = [x1 x2 x3 x4 x5] T =[1.060 1.069 0.994 0.884 0.158] T

[0134] Since the maximum value of each element in the column vector x is x max is 1.069, so

[0135] Based on this, the matching ratio of gears A, B, C, D, and E is determined to be 0.99:1.00:0.93:0.83:0.15, and the return (or storage) ratio of each gear is 1%, 0.7%, 17%, and 85% respectively.

[0136] In the fourth step, the separation control module in the system determines that the angle-adjustable baffle in the discharge and return control unit configured in the control gear A is opened 89.1° relative to the discharge port; the angle-adjustable baffle in the discharge and return control unit configured in the control gear B is opened 90° relative to the discharge port; the angle-adjustable baffle in the discharge and return control unit configured in the control gear C is opened 83.7° relative to the discharge port; the angle-adjustable baffle in the discharge and return control unit configured in the control gear D is opened 74.7° relative to the discharge port; the angle-adjustable baffle in the discharge and return control unit configured in the control gear E is opened 13.5° relative to the discharge port.

[0137] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the foregoing embodiments. The foregoing embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for adjusting the particle gradation of machine-made sand without fine screening, characterized in that: include: Step (1), determine basic parameters; Based on the number of particle sizes n of the finished machine-made sand, the number of gears n equal to it is determined; Step (2), measuring the output; Measure the discharge amount of each grade of material per unit time in each gear; Step (3), calculating and determining the take-in ratio and the return ratio; Based on the number of particle sizes and the number of gears determined in step (1) and the discharge amount of each particle size per unit time measured in step (2), a comprehensive calculation is performed to determine the take-in ratio and the return ratio; Step (4), regulating the discharge amount of the discharge port; According to the take-in ratio and return ratio determined in step (3), a control instruction of the discharge and return control unit corresponding to each material is generated, and the discharge and return control unit is controlled to separate the required material and excess material of each gear according to the ratio in the third step.

2. The method for adjusting the particle gradation of machine-made sand without fine screening according to claim 1, characterized in that: In the step (1), for the required finished sand particle gradation, a corresponding finished sand particle gradation data model is constructed based on the mass percentage of each particle size.

3. The method for adjusting the particle gradation of machine-made sand without fine screening according to claim 1, characterized in that: In the step (2), a corresponding discharge quantity data model is constructed for the discharge quantity of each particle size material at each gear.

4. The method for adjusting the particle gradation of machine-made sand without fine screening according to claim 1, characterized in that: In the step (3), a usage ratio model is constructed according to the relationship between the particle gradation number of the finished sand and the discharge amount of each particle size material, and the usage ratio model is converted into a corresponding matrix equation; Next, for the converted matrix equation, the use ratio and return ratio are calculated based on the number of particle sizes and the number of gears determined in step (1) and the discharge amount of each particle size per unit time measured in step (2).

5. The method for adjusting the particle gradation of machine-made sand without fine screening according to claim 1, characterized in that: In step (4), the excess material separated is returned to the original material system, and steps (2) to (4) are repeated.

6. The fine screening-free machine-made sand particle grading adjustment system is characterized by: Multiple modules work together, including: A finished sand particle grading module, which determines the number of particle grades and the number of equal gears of the finished machine-made sand, and generates a finished sand particle grading data model accordingly; A discharge quantity measurement module, which is connected to the data of the automatic particle size detection instrument, can measure the discharge quantity of each particle size material in each gear material per unit time, and generate a discharge quantity data model; A ratio calculation module, which exchanges data with the finished sand particle grading module and the discharge quantity measurement module, and calculates and determines the take ratio and the return ratio; A separation control module, which interacts with the proportion calculation module and controls the connection of the material discharging and returning control unit. The separation control module can form control instructions according to the taking ratio and return ratio calculated and determined by the proportion calculation module, so as to control the material discharging and returning control unit to separate the required materials and excess materials of each gear in proportion.

7. The fine screening-free machine-made sand particle grading adjustment system according to claim 6 is characterized in that: The finished sand particle grading data model generated by the finished sand particle grading module is a matrix data model constructed based on the mass percentage of each particle size.

8. The fine screening-free machine-made sand particle grading adjustment system according to claim 6 is characterized in that: The discharge amount data model generated by the discharge amount measurement module is a matrix data model constructed based on the discharge amount of each particle size material at each gear.

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