Method and system for separating effective breakage work from dissipated energy in a bed of material being comminuted

Abstract

This invention discloses a method and system for separating and determining the effective crushing work and dissipated energy in a bed pulverizer. The method includes: obtaining the input and output materials from an industrial bed pulverizer; and performing particle size analysis to determine that 80% of the input material passes through a sieve with an aperture size of X. 80 The sieve aperture Y through which 80% of the sampled material passes. 80 Establish the correlation between the laboratory single-extrusion effect and the industrial pulverization effect, and determine the equivalent extrusion force F; conduct a cyclic extrusion equilibrium test on the sample material using F, and obtain the average mechanical work and average fine powder yield after reaching equilibrium; perform particle size analysis on the equilibrium material to obtain that 80% of the fine powder passes through the sieve aperture P. 80 Based on X 80 P 80 Calculate the extrusion work index Eᵢ; then, based on Eᵢ and X... 80 Y 80 Calculate effective power W e Total input power W t Dissipated energy W h Energy separation is achieved. In a laboratory environment, through equivalent pressure and cycle balance tests, the effective work and dissipated energy of industrial material bed crushing are accurately separated and quantitatively measured, establishing an energy efficiency evaluation system.

Description

Technical Field

[0001] This invention relates to the field of bed crushing technology, and in particular to a method and system for separating and measuring effective crushing work and dissipated energy in bed crushing. Background Technology

[0002] High-pressure bed grinding technology (such as roller presses and vertical mills) is a core grinding process in the cement, mining and other fields. With its advanced concept of "more crushing and less grinding", it significantly reduces the energy consumption per unit product and has become a key piece of equipment for energy conservation and carbon reduction in the industry. However, the energy utilization rate of this process has always hovered at a low level of 35%-50%, and a large amount of input energy is dissipated in the form of heat and vibration, resulting in huge energy waste.

[0003] For a long time, the industry has generally used the Bond work index as a macro-level indicator to evaluate the energy consumption of material crushing. However, the Bond work index can only reflect the total specific energy consumption required for crushing, and cannot analyze how much of the total energy consumption is comprised of "effective work" used to achieve particle crushing and "dissipated energy" wasted in the form of heat. This "black box" state of energy distribution leads to a core dilemma for production enterprises: they cannot determine whether high power consumption stems from the difficulty in crushing the material itself, or from low equipment efficiency or improper process parameter settings. This makes energy-saving renovations lack clear guidelines, often leading to blind adjustments of working pressure based on experience, which can easily cause production problems such as material blockage and over-grinding, and even exacerbate equipment wear.

[0004] To analyze the energy distribution in bed crushing, existing technologies mainly employ the following approaches, but all have significant limitations: Piston extrusion-thermodynamic analysis: This method involves extruding material in a single pass on a laboratory piston press, calculating the total input work by integrating the stress-strain curve, and calculating heat dissipation by temperature measurement. However, a single extrusion cannot simulate the cyclic loading process of material in an industrial roller press, and the heat energy measurement has significant errors due to heat transfer losses. More importantly, this method cannot separate the effective crushing work.

[0005] Discrete Element Method (DEM): This method simulates energy dissipation by establishing a particle swarm model. However, it is highly dependent on pre-defined constitutive parameters (such as elastic modulus and friction coefficient). Since actual material properties are complex and variable, the calculation results often deviate from reality by as much as 20%-40%, making it unsuitable for accurate industrial energy efficiency assessment and guidance.

[0006] Energy conversion methods (such as the water temperature rise method): This method calculates heat dissipation by measuring the temperature rise caused by placing the crushed material in water. However, this method also cannot avoid energy loss during heat transfer, has significant errors, and cannot obtain quantitative data on effective work.

[0007] In summary, existing technologies, due to distorted operating conditions, parameter sensitivity, or fundamental flaws, have failed to achieve accurate and practical separation of effective work and dissipated energy during bed grinding. Developing a low-cost measurement method capable of reproducing industrial operating conditions and accurately quantifying energy distribution has become an urgent need to overcome the energy efficiency bottleneck in bed grinding and achieve precise energy saving and carbon reduction. Summary of the Invention

[0008] The purpose of this invention is to provide a method and system for separating and measuring effective crushing work and dissipated energy in bed crushing. Under laboratory conditions, through equivalent extrusion pressure determination and cyclic equilibrium experiments, the accurate separation and quantitative measurement of effective crushing work and dissipated energy in the energy distribution of industrial bed crushing were achieved, and a method based on the effective work ratio k was established. e The value-based energy efficiency evaluation system provides directly applicable data support for energy efficiency diagnosis and process optimization in industrial production.

[0009] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention discloses a method for separating and measuring the effective crushing work and dissipated energy in a material bed crushing process, comprising the following steps: S1. Obtain the feed material and discharge material from the industrial bed pulverizer, and perform particle size analysis to determine the particle size distribution of the feed material. 80% of the feed material passes through the sieve aperture X. 80 80% of the sampled material passes through the sieve aperture Y. 80 ; S2. Establish the correlation between the effect of a single extrusion test in the laboratory and the effect of industrial bed crushing to determine the equivalent extrusion force F; S3. Conduct a cyclic extrusion equilibrium test on the sample material using an extrusion pressure F, and obtain the average mechanical work done during the test after the test reaches equilibrium. Compared with average fine powder yield ; S4. Perform particle size analysis on the material after the cyclic equilibrium test to obtain the sieve aperture P through which 80% of the fine powder portion of the material passes. 80 Based on X 80 P 80 , , Calculate the extrusion work index E of the material. i Based on E i X 80 Y 80 , To obtain the effective work W of material crushing e Total input power W t ; S5, according to W e and W t The difference in energy dissipation W is worth hThis achieves the separation of effective crushing work and dissipated energy.

[0010] Furthermore: In step S2, the specific correlation between establishing the effect of a single laboratory extrusion test and the effect of industrial bed crushing is as follows: The baseline value of fine powder ratio n1 of the industrial sample material is compared with the experimental fine powder ratio n2 obtained from a single extrusion test in the laboratory under different extrusion pressures. When | n 2- When n1| < 3%, confirm the extrusion pressure F.

[0011] Further: In step S3, the experiment reaches equilibrium by: after each ballast, the generated fine powder is removed and an equal mass of the original sample material is added to keep the total mass of the material constant during each ballast; after three consecutive ballasts, the difference between the maximum and minimum fine powder output is no more than 1% of the average fine powder output.

[0012] Further: In step S4, the effective power W e It is obtained through the following calculation formula:

[0013] In the formula, E i X represents the extrusion work index of the material, expressed in kWh / t. 80 Y represents the sieve aperture size corresponding to 80% of the sample material passing through, in micrometers; 80 The sieve aperture is the size of the sample material when 80% of it passes through, in micrometers; G is the fine powder yield obtained through a single extrusion test in the laboratory under extrusion pressure F, in grams.

[0014] Further: Extrusion work index E i It is obtained through the following calculation formula:

[0015] In the formula, E i The extrusion work index of the material is expressed in kWh / t. The average work done by the press on material crushing during cyclic equilibrium is expressed in J. X represents the average amount of fine powder after material crushing at the point of equilibrium, expressed in grams. 80 P represents the sieve aperture size corresponding to 80% of the sample material passing through, in micrometers; 80 The sieve aperture is the size of the fine powder obtained after the cyclic equilibrium test, corresponding to the passage of 80% of the powder. The unit is micrometers.

[0016] Furthermore, it also includes step S6: calculating the effective power percentage. and with The core energy efficiency indicators are used to determine the energy efficiency level of the operating conditions.

[0017] Furthermore, the determination specifically refers to: using the effective power ratio k under the first operating condition. e0 Based on this, the effective power ratio k obtained after changing equipment parameters or materials is... e1 Greater than k e0 If the current operating condition is deemed to have higher energy efficiency, then it is determined that the current operating condition is more energy efficient.

[0018] Furthermore: the fine powder is a material with a particle size of 45-200μm.

[0019] Secondly, this invention discloses a bed pulverizing energy separation and measurement system as described above, comprising: The particle size analysis module is used to perform particle size analysis on the input material, the output material, and the material after the cyclic equilibrium test. The equivalent pressure determination module is used to determine the equivalent extrusion force F based on the fine powder ratio benchmark value n1 of the sampled material and the test fine powder ratio n2 obtained from a single extrusion test. The cyclic test control module is used to perform cyclic extrusion balance tests with equivalent extrusion force F and collect mechanical work and fine powder production data. The energy calculation module is used to calculate the effective work (W) based on particle size data, mechanical work, and fine powder production data. e Total input power W t and dissipated energy W h .

[0020] Furthermore, the system also includes an energy efficiency evaluation module, used to evaluate the calculated effective power ratio k. e The value generates energy efficiency diagnostic results or parameter adjustment suggestions.

[0021] Compared with the prior art, the beneficial effects of the present invention are: This invention simulates real industrial conditions through cyclic equilibrium experiments and introduces an equivalent extrusion work index calculation model based on Bond theory, successfully separating the total input work of material crushing into effective work and dissipated energy. This transforms energy utilization from vague macroscopic power consumption data into a clear, visible, and quantifiable distribution of energy components.

[0022] The effective power ratio can be directly used for: 1) Energy efficiency diagnosis: quickly determining whether high power consumption is due to the difficulty in crushing materials or low equipment efficiency (such as roller surface wear); 2) Parameter optimization: by finding k under different pressures and materials. e The peak value is determined to establish the optimal operating range and maximize the effective powder production per unit of electricity; 3) It provides verifiable and accurate energy efficiency benchmark data for carbon footprint accounting and carbon trading. This completely changes the outdated model of blindly adjusting based on experience, and provides core technical support for the intelligent and refined operation of bed crushing. Attached Figure Description

[0023] Figure 1 This is an overall flowchart of the method for separating and measuring effective crushing work and dissipated energy in the material bed crushing process of the present invention.

[0024] Figure 2 This is a schematic diagram illustrating the determination of the equivalent extrusion force F in this invention.

[0025] Figure 3 This is a schematic diagram of the cyclic equilibrium test conducted in this invention.

[0026] Figure 4 This is a trend diagram showing the relationship between the extrusion pressure F and the corresponding fine powder ratio n2 in an embodiment of the present invention.

[0027] Figure 5 This is a convergence trend diagram of the fine powder production G in the cyclic equilibrium stage of this invention. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] In this embodiment, taking a roller press crushing system in a cement plant as an example, the method for separating and measuring the effective crushing work and dissipated energy in the material bed crushing of the present invention is described in detail.

[0030] Step 1: Industrial Site Sampling and Particle Size Analysis First, representative input materials were obtained from the inlet of the industrial roller press, and output materials were obtained from its outlet. These two samples were then sieved using a vibrating sieve or a laser particle size analyzer to obtain their particle size distribution data, as shown in Tables 1 and 2, respectively.

[0031] Table 1. Particle size distribution data of the sampled material

[0032] Table 2 Particle size distribution data of sampled materials

[0033] The characteristic particle size X of the sample material was calculated from the data in Table 1 using linear interpolation. 80 = 4428.40μm, characteristic particle size Y of the sample material 80 = 2238.12. The baseline value of fine powder ratio of the sample material calculated from the data in Table 2 is n1 = 20.37% (fine powder in this embodiment is defined as 80μm sieve undersize material).

[0034] Step 2: Determine the equivalent extrusion pressure F On a laboratory piston press, multiple single-expansion tests were conducted on the same weight of sample material under different extrusion pressures F. After each extrusion, the product was sieved to obtain the percentage of fine powder n2 corresponding to different pressures. The data are recorded in Table 3.

[0035] Table 3. Data on the percentage of fine powder corresponding to extrusion pressure

[0036] As shown in Table 3, when the deviation between n2=20.87% and n1=20.37% under 114.59MPa extrusion is 2.47% < 3%, the extrusion pressure F corresponding to the piston ballast test equivalent to industrial crushing efficiency can be determined to be 114.59MPa, which is the extrusion pressure corresponding to n2=20.87% at this time. The trend is as follows. Figure 4 As shown.

[0037] Operating method: Compare the n2 values ​​under different pressures with the industrial benchmark n1. (See Table 3 and appendix.) Figure 4 It can be seen that when the pressure is 114.59 MPa, n2 = 20.87%, and the relative deviation from n1 (20.37%) is 2.47% < 3%, which meets the preset standard. Therefore, the equivalent extrusion pressure F = 114.59 MPa is determined.

[0038] Step 3: Cyclic Equilibrium Test Using the equivalent extrusion pressure F = 114.59 MPa determined above, a cyclic extrusion equilibrium test was conducted on 500g of sample material. This step is the core of achieving precise energy separation. Industrial roller presses involve multiple cycles of loading. After extrusion, the material is sorted by equipment such as a classifier. The coarse particles are returned for further extrusion, while the qualified fine particles enter subsequent processes. If the material gradation, equipment conditions, and system operating parameters remain stable, the input and output of this system will reach a state of equilibrium after a period of operation. A single test cannot simulate this process, leading to distortion of energy composition. The cyclic equilibrium test of this invention simulates the process of material circulation through a roller press in industry by dynamically removing fine powder and adding equal-weight material, achieving a dynamic balance between the energy distribution under laboratory conditions and the industrial scenario. This lays the foundation for accurately measuring the total input work and calculating the effective work.

[0039] After each compression, all fine powder produced was removed, and an equal weight of the original sample was added to maintain a total weight of 500g. This process was repeated until the system reached equilibrium. The equilibrium criterion was: the ratio of the difference between the maximum and minimum fine powder yield to its average value for the last three consecutive cycles was ≤ 1%. The experimental data are recorded in Table 4, and the convergence trend of fine powder yield is shown in the attached figure. Figure 5 As shown. After reaching equilibrium, record the average mechanical work done in the last three compressions. = 1834.43 J and average fine powder yield = 82.87 g. The fine powder products from the last three batches were mixed thoroughly and then sieved to obtain their particle size distribution (see Table 5). The characteristic particle size P was then determined by interpolation. 80 = 51.45μm.

[0040] Table 4. Extrusion work and fine powder production data from the cyclic equilibrium test.

[0041] Table 5. Particle size distribution data of fine powder after extrusion

[0042] Step 4: Energy Distribution Calculation Calculations were performed using data obtained from cyclic equilibrium experiments, based on the principles of Bond's pulverization theory.

[0043] (1) Calculate the extrusion work index E i :

[0044] Average mechanical work = 1834.43 J, average fine powder yield = 82.87 g, X 80 = 4428.40μm, P 80 =51.45μm, substituting into the above formula, we obtain the extrusion work index E of the material under this extrusion pressure. i =4.943kWh / t.

[0045] (2) Calculate effective work With dissipated energy W h :

[0046] E i =4.943kWh / t, X 80 = 4428.40μm, Y 80 = 2238.12μm, material from X 80 Break to Y 80 The amount of fine powder after crushing Substituting 104.35g into the above formula, we obtain the effective work. =113.47J; First, calculate the total breaking work W. t That is, the particle size of the material is crushed by the press from X 80 Broken to Y80 The required work is the total work done in the first compression during the experiment, W. t =2170.96J.

[0047] Then, W t =2170.96J and =113.47J. Substitute into the following formula to calculate the dissipated energy; W h = W t -W e Get W h =2057.49 J.

[0048] (3) Calculate the energy distribution ratio: Will =113.47J and W t =2170.96J Substitute into the formula To obtain the effective power ratio The proportion of dissipated energy. .

[0049] Step 5: Determine Energy Efficiency Improvement As a visual indicator of energy distribution, the energy efficiency ratio (k) is a core criterion for improving energy efficiency. It transforms complex energy flows into a simple and intuitive numerical value, providing a clear direction for control in industrial production. When the equivalent pressure F or the material changes, the effective work ratio (k) under that operating condition can be obtained using the above method. e1 When k e1 A value greater than 5.23% is considered a high-efficiency operating condition; otherwise, it is considered an inefficient operating condition. For example, if k is changed... e A sharp drop in kJ / k value to 3.5% (inefficient operating conditions) may indicate that the replaced material is more difficult to grind. This can be addressed by increasing the pressure from 114 MPa to a higher pressure (e.g., 125 MPa) or by adding grinding aids. e This value can lead to a rebound in the indicators, thereby achieving the goal of reducing electricity consumption per ton and increasing annual efficiency. e This technology transforms the energy consumption of bed crushing from a "black box" to a "visual dashboard," upgrading "powder production per kilowatt-hour" to "effective powder production per kilowatt-hour," providing a core benchmark for precise energy saving and carbon emission reduction in the powder industry.

[0050] This invention develops a laboratory-level equivalent testing method that uses less material and is simple to operate. It obtains extrusion pressure equivalent to industrial production crushing efficiency through a single extrusion plus a cyclic balance test, reproduces the energy distribution of industrial roller presses, and achieves precise separation of energy components. The total work done in material crushing is divided into effective work and dissipated energy, and a mapping model of extrusion pressure-material-energy distribution is constructed. This model can be used to guide and evaluate the parameter optimization of material bed crushing equipment such as industrial roller presses.

[0051] This embodiment also discloses a bed pulverizing energy separation and measurement system used in the above method, including: The particle size analysis module is used to perform particle size analysis on the input material, the output material, and the material after the cyclic equilibrium test. The equivalent pressure determination module is used to determine the equivalent extrusion force F based on the fine powder ratio benchmark value n1 of the sampled material and the test fine powder ratio n2 obtained from a single extrusion test. The cyclic test control module is used to perform cyclic extrusion balance tests with equivalent extrusion force F and collect mechanical work and fine powder production data. The energy calculation module is used to calculate the effective work (W) based on particle size data, mechanical work, and fine powder production data. e Total input power W t and dissipated energy W h .

[0052] Furthermore, the system also includes an energy efficiency evaluation module, used to evaluate the calculated effective power ratio k. e The value generates energy efficiency diagnostic results or parameter adjustment suggestions.

[0053] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0054] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A method for separating and determining the effective crushing work and dissipated energy in a bed crushing process, characterized in that, Includes the following steps: S1. Obtain the feed material and discharge material from the industrial bed pulverizer, and perform particle size analysis to determine the particle size distribution of the feed material. 80% of the feed material passes through the sieve aperture X. 80 And 80% of the sampled material passes through the sieve aperture Y 80 ; S2. Establish the correlation between the effect of a single laboratory extrusion test and the effect of industrial bed pulverization to determine the equivalent extrusion pressure F, and obtain the fine powder yield G of a single extrusion test under this equivalent extrusion pressure F; the correlation specifically involves comparing the benchmark value n1 of the fine powder ratio of the industrial sample material with the experimental fine powder ratio n2 obtained from a single laboratory extrusion test under different extrusion pressures, when |n 2- When n1 < 3%, the equivalent extrusion pressure F is confirmed; S3. Conduct a cyclic extrusion equilibrium test on the sample material using an equivalent extrusion force F, and after the test reaches equilibrium, obtain the average mechanical work done by the last three consecutive extrusions during the test. Compared with average fine powder yield The experiment to achieve equilibrium specifically involves: after each ballast load, removing the generated fine powder and replenishing it with an equal mass of the original sample material, ensuring that the total mass of material remains constant during each ballast load; after three consecutive ballast loads, the ratio of the difference between the maximum and minimum fine powder production values ​​to the average fine powder production value does not exceed 1%; the total input power W t Defined as the particle size of material after being crushed by a press, which is determined by X. 80 Broken to Y 80 The required work is the total work done in the first compression during the experiment; S4. Perform particle size analysis on the material after the cyclic equilibrium test to obtain the sieve aperture P of 80% of the fine powder portion passing through the material in the last three continuous extrusions. 80 Based on X 80 P 80 , , The extrusion work index E of the material was calculated using Bond theory. i Based on E i X 80 Y 80 G, using Bond theory to calculate the effective work W for material crushing. e ; S5, according to W e and W t The difference in energy dissipation W is worth h This achieves the separation of effective crushing work and dissipated energy.

2. The separation and determination method according to claim 1, characterized in that, In step S4, the effective power W e It is obtained through the following calculation formula: In the formula, E i X represents the extrusion work index of the material, expressed in kWh / t. 80 Y represents the sieve aperture size corresponding to 80% of the sample material passing through, in micrometers; 80 The sieve aperture is the size of the sample material when 80% of it passes through, in micrometers; G is the fine powder yield obtained through a single extrusion test in the laboratory under the equivalent extrusion pressure F, in grams.

3. The separation and determination method according to claim 2, characterized in that, Extrusion work index E i It is obtained through the following calculation formula: In the formula, E i The extrusion work index of the material is expressed in kWh / t. The average work done by the press on material crushing during cyclic equilibrium is expressed in J. X represents the average amount of fine powder after material crushing at the point of equilibrium, expressed in grams. 80 P represents the sieve aperture size corresponding to 80% of the sample material passing through, in micrometers; 80 The sieve aperture is the pore size corresponding to when 80% of the fine powder obtained from the last three consecutive extrusions in the cyclic equilibrium test passes through, and the unit is micrometers.

4. The separation and determination method according to claim 1, characterized in that, It also includes step S6: calculating the effective power percentage. and with The core energy efficiency indicators are used to determine the energy efficiency level of the operating conditions.

5. The separation and determination method according to claim 4, characterized in that, The determination is specifically based on the effective power ratio k under the first operating condition. e0 Based on this, the effective power ratio k obtained after changing equipment parameters or materials is... e1 Greater than k e0 If the current operating condition is deemed to have higher energy efficiency, then it is determined that the current operating condition is more energy efficient.

6. The separation and determination method according to any one of claims 1-5, characterized in that, The fine powder is a material with a particle size of 45-200μm.

7. A material bed pulverizing energy separation and measurement system for implementing the method according to any one of claims 1-6, characterized in that, include: The particle size analysis module is used to perform particle size analysis on the input material, the output material, and the material after the cyclic equilibrium test. The equivalent pressure determination module is used to determine the equivalent extrusion force F based on the fine powder ratio benchmark value n1 of the sampled material and the test fine powder ratio n2 obtained from a single extrusion test. The cyclic test control module is used to perform cyclic extrusion balance tests with equivalent extrusion force F and collect mechanical work and fine powder production data. The energy calculation module is used to calculate the effective work (W) based on particle size data, mechanical work, and fine powder production data. e Total input power W t and dissipated energy W h .

8. The system according to claim 7, characterized in that, The system also includes an energy efficiency evaluation module, used to evaluate the calculated effective power ratio k. e The value generates energy efficiency diagnostic results or parameter adjustment suggestions.

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