Screening machine screen mesh aperture adjustment calculation method

Abstract

The invention discloses a screening machine screen mesh aperture adjusting and calculating method. The method comprises the following steps that firstly, the screen mesh size a of screening equipment without screen mesh replacement is measured; 2, detecting the nominal maximum particle size accumulated screen residue P1 of the collected materials under the screen holes of the original screen mesh; step 3, acquiring the nominal maximum particle size b of the aggregate in the specification corresponding to the original screen; 4, determining the nominal maximum particle size accumulated screen residue P2 of the collected material under the screen after the screen is replaced; 5, a mathematical model (a-b): lgP1 = (c-b): lgP2 is created by performing data statistical analysis and summarization on a large amount of a, b, P1 and P2 and the sizes of the screen holes of the replacement screen obtained through test detection; step 6, substituting the a of the to-be-replaced screen, the P1 of the to-be-replaced screen and the determined P2 into the mathematical model, and calculating a theoretical value c of the mesh size of the to-be-replaced screen; and 7, finally determining the size of the screen holes of the replacement screen. According to the method, data are substituted into the model through test detection, the mesh size of the screen is determined, and the nominal maximum particle size passing rate of the aggregate in the future is accurately calculated.

Description

Technical Field

[0001] The invention relates to the technical field of aggregate material processing, and in particular to a method for calculating the adjustment of the aperture of a sieve mesh of a screening machine. Background Art

[0002] Due to the differences in project design and purpose, the specifications of aggregate materials vary greatly, and often fail to meet project requirements. When purchasing aggregate materials, the construction party selects the manufacturer based on comprehensive consideration of other properties of the aggregate materials, so the specifications of the purchased aggregate materials may be inappropriate. In order to avoid the situation where the manufacturer needs to adjust the aggregate specifications for the second time, which will increase costs and delay the construction period, the construction party needs to clearly change the aperture of the screen and inform the manufacturer to produce and process the aggregate materials. At present, the determination of the aperture of the screen is based on the experience of technicians, and there is no scientific and complete calculation theory. The accuracy of the aperture of the screen predicted by the technicians is low. In the process of aggregate material production, not only is the production efficiency low, but also because the aggregate material specifications do not fully meet the needs of the project, it will cause great waste. Summary of the invention

[0003] The purpose of the present invention is to provide a method for calculating the adjustment of the mesh aperture of a screening machine. The method determines the mesh aperture (size) by substituting data into the model through experimental detection.

[0004] To achieve the above object, the present invention adopts the following technical solutions: A method for calculating the adjustment of the aperture of a screening machine screen comprises the following steps: Step 1: Measure the mesh size a (mm) of the screening equipment before the screen is replaced; Step 2: Detect the nominal maximum particle size of the aggregate under the original sieve mesh and the cumulative sieve residue P1 (%); Step 3: Obtain the nominal maximum aggregate size b (mm) in the specification corresponding to the original sieve; Step 4, determine the nominal maximum particle size of the aggregate under the sieve after the sieve is replaced and the cumulative residue P2 (%); Step 5, Step 5, by statistically analyzing and summarizing a large number of a, b, P1, P2 and the replacement screen mesh sizes obtained by experimental detection, a mathematical model (ab):lgP1= (cb):lgP2 is created; Step 6: Substitute the a of the screen to be replaced, P1 of the screen to be replaced and the determined P2 into the mathematical model to calculate the theoretical value c (mm) of the sieve hole size of the screen to be replaced; Step seven, finally determine the size of the sieve holes to be replaced.

[0005] Preferably, the value range of P2 is 0-10%.

[0006] Preferably, the P2 value is 5%.

[0007] Preferably, in step seven, when the mesh hole size c calculated by the mathematical model is not an integer, an integer is obtained by truncation and rounding up respectively, and the two integers are substituted into the formula in turn to calculate two P2s, and the integer closest to 5% of P2 is selected as the mesh hole size for replacement.

[0008] Preferably, the size of the sieve holes of the replacement sieve is the sieve hole diameter of the round hole sieve or the sieve hole side length of the square hole sieve.

[0009] Preferably, the mesh size accuracy of the sieve is 1 mm.

[0010] Preferably, P1 is related to the mesh size of the sieve. The closer the mesh size of the sieve is to the nominal maximum aggregate particle size b, the smaller P1 is; and the farther the mesh size of the sieve is from the nominal maximum aggregate particle size b, the larger P1 is.

[0011] The present invention abandons the conventional method of predicting the mesh openings of the screen by technicians based on experience, avoids the need for secondary adjustment of the screen of the screening machine during the aggregate material processing process, and calculates the mesh openings of the screen by a mathematical model before the screen is replaced.

[0012] Through the measurement of a large number of screen holes and the test results of lower aggregate screening, as well as the measurement and detection of many screen adjustments, a scientific mathematical model was created after analysis and summary. The size of the replacement screen holes was calculated through the mathematical model, providing a more accurate method for adjusting and replacing the screen holes of the vibrating screen on the screening machine.

[0013] Compared with the prior art, the present invention improves the accuracy of adjusting the screen mesh holes and is extremely easy to master. At the same time, it avoids the time-consuming and labor-intensive problems such as secondary adjustment that seriously affect production.

[0014] After repeated verification on a large number of screening machines, the mesh size accuracy is 1 mm. DETAILED DESCRIPTION

[0015] The present invention is further described: A method for calculating the adjustment of the aperture of a screening machine screen comprises the following steps: Step 1: Measure the mesh size a (mm) of the screening equipment before the screen is replaced; Step 2: Detect the nominal maximum particle size of the aggregate under the original sieve mesh and the cumulative sieve residue P1 (%) by screening method; Step 3: Obtain the nominal maximum aggregate size b (mm) in the specification corresponding to the original sieve; Step 4: Determine the nominal maximum particle size of the aggregate under the screen after replacing the screen, and the cumulative screen residue P2 (%). Referring to the existing technical specifications, it can be known that the value range of P2 is 0-10%. In a preferred embodiment, the value of P2 is 5%; Step 5, by statistically analyzing and summarizing a large number of a, b, P1, P2 and the replacement screen mesh sizes obtained by test, a mathematical model (ab):lgP1= (cb):lgP2 is created; Step 6: Substitute the a of the screen to be replaced, P1 of the screen to be replaced and the determined P2 into the mathematical model to calculate the theoretical value c (mm) of the sieve hole size of the screen to be replaced; Step seven, finally determine the size of the sieve hole to be replaced, the sieve hole size to be replaced is the sieve hole diameter of the round hole sieve or the sieve hole side length of the square hole sieve. Specifically, when the sieve hole size c calculated by the mathematical model is not an integer, obtain an integer using the truncation method and the rounding method respectively, substitute the two integers into the formula in turn, calculate two P2s in succession, and select the integer closest to 5% of P2 as the sieve hole size to be replaced.

[0016] The mesh size accuracy is 1 mm.

[0017] Example: The upper layer of the asphalt pavement of a certain highway is SMA-13, and 10-15mm crushed stone needs to be purchased. However, the basalt crushing plant uses a sieve with a mesh size of 13.2mm to screen the 10-15mm crushed stone. The test results show that P1 is 82.5% and P2 is 17.5%, which is greater than the 0-10% requirement. The mesh size a of the screening equipment without replacing the mesh is 16mm.

[0018] Substituting a=16 and b=13.2 into (ab):lgP1= (cb):lgP2 yields: (16-13.2):lg17.5= (c-13.2):lg8, The solution is: c=15.234.

[0019] Substitute c=15 and c=16 into (ab):lgP1= (cb):lgP2 respectively, and solve to get P2≈6.3 or P2≈17.5. It can be seen that when c=15 meets the requirements, the mesh size of the sieve should be changed to 15.

[0020] Different screening machines have different screening effects under normal circumstances, but the screening results of aggregates under a certain layer of the same screening machine should theoretically be within a very small range. After a small adjustment of the mesh holes of this layer of the screen, the corresponding aggregate screening results are also within a very small range, and their screening effects are basically the same. There is an inevitable rule between the mesh hole adjustment and the aggregate screening results: the closer the mesh holes of a certain layer of the same screening machine are to the nominal maximum aggregate particle size b, the smaller P1 is; the farther the mesh holes are from the nominal maximum aggregate particle size b, the larger P1 is. The two are in a positive proportional relationship and are both linear, but not a linear relationship.

[0021] The above embodiments are only some illustrations of the concept and implementation of the present invention, and are not intended to limit the same. Under the concept of the present invention, technical solutions that have not been substantially changed are still within the scope of protection.

Claims

1. A method for calculating the adjustment of the aperture of a screening machine screen, characterized in that: The following steps are involved: Step 1: Measure the mesh size a (mm) of the screening equipment before the screen is replaced; Step 2: Detect the nominal maximum particle size of the aggregate under the original sieve mesh and the cumulative sieve residue P1 (%); Step 3: Obtain the nominal maximum aggregate size b (mm) in the specification corresponding to the original sieve; Step 4, determine the nominal maximum particle size of the aggregate under the sieve after the sieve is replaced and the cumulative residue P2 (%); Step 5, by statistically analyzing and summarizing a large number of a, b, P1, P2 and the replacement screen mesh sizes obtained by test, a mathematical model (ab):lgP1= (cb):lgP2 is created; Step 6: Substitute the a of the screen to be replaced, P1 of the screen to be replaced and the determined P2 into the mathematical model to calculate the theoretical value c (mm) of the sieve hole size of the screen to be replaced; Step seven, finally determine the size of the sieve holes to be replaced.

2. The method for calculating the adjustment of the aperture of the sieve mesh of the screening machine according to claim 1, characterized in that: The value range of P2 is 0-10%.

3. The method for calculating the adjustment of the aperture of the sieve mesh of the screening machine according to claim 2, characterized in that: The P2 value is 5%.

4. The method for calculating the adjustment of the aperture of the sieve mesh of the screening machine according to claim 3, characterized in that: In step seven, when the mesh hole size c calculated by the mathematical model is not an integer, an integer is obtained by truncation and rounding up respectively, and the two integers are substituted into the formula in turn to calculate two P2s, and the integer closest to 5% of P2 is selected as the mesh hole size for replacement.

5. The method for calculating the adjustment of the aperture of the sieve mesh of a screening machine according to claim 1 or 4, characterized in that: The size of the sieve holes of the replacement sieve is the sieve hole diameter of the round hole sieve or the sieve hole side length of the square hole sieve.

6. The method for calculating the adjustment of the aperture of the sieve mesh of the screening machine according to claim 5, characterized in that: The mesh size accuracy of the sieve is 1 mm.

7. The method for calculating the adjustment of the aperture of the sieve mesh of the screening machine according to claim 1, characterized in that: The P1 is related to the mesh size of the sieve. The closer the mesh size of the sieve is to the nominal maximum aggregate particle size b, the smaller the P1 is; the farther the mesh size of the sieve is from the nominal maximum aggregate particle size b, the larger the P1 is.