Mechanism sand moisture content on-line detection method and control system

Abstract

The application provides an online detection method for water content of machine-made sand, wherein a correction amount lambda is introduced in the detection method of the application, so that the actual water content of the machine-made sand falls within the range of Phi n + / -lambda; and the interval of the actual water content is narrowed through overlapping of n intervals A, so as to improve the detection precision of the water content. Therefore, the application improves the detection efficiency and the detection precision of the water content, and eliminates the situation that the efficiency and the precision cannot be ensured simultaneously in the previous detection.

Description

Technical Field

[0001] This invention relates to the field of building material preparation technology, specifically to an online detection method and control system for the moisture content of manufactured sand. Background Technology

[0002] Moisture content, as one of the physical properties of manufactured sand, is a physical quantity used to determine whether manufactured sand meets the factory standards. Therefore, in the wet sand making process, manufactured sand is usually dried to a moisture content of 3% to 5% before it can be delivered to the site for use. Therefore, testing the moisture content of manufactured sand before it leaves the factory is quite important.

[0003] Currently, when online moisture content testing is required during manufactured sand production, it is done manually, typically using either the drying method or the resistance testing method. The drying method offers higher accuracy, reaching ±0.1%, which can be considered the actual moisture content of the manufactured sand. However, its efficiency is low, requiring at least one hour per test. While the resistance testing method is highly efficient, its accuracy is lower, only reaching ±0.5%. Since existing testing methods generally select one of these two approaches, this approach cannot simultaneously meet the demand for efficient and accurate online moisture content testing of manufactured sand. Summary of the Invention

[0004] The purpose of this invention is to design an online method for detecting the moisture content of manufactured sand, in order to solve the problems mentioned in the background art. To achieve the above objective, this invention provides the following detection method:

[0005] Step 1: Take a portion of test sand from the dried sand pile and then divide the test sand into a portion of dried test sand and several portions of resistance test sand.

[0006] Step 2: The moisture content of the sand used for drying and testing is determined by the drying method, and the moisture content of several samples of sand used for resistance testing is determined by the resistance testing method. Let the moisture content of the sand used for drying and testing be α, and the moisture content of the sand used for resistance testing be β1, β2, β3, β4...β n ;

[0007] Step 3: Transfer β1 to β n Subtract α from each of the following and take the absolute values ​​γ1 to γ2. n Remove γ1 to γ n There are j differences greater than 0.5%;

[0008] Step 4: Let the correction amount λ be the average value of the remaining γ values, that is... ;

[0009] Step five, when the moisture content of the artificial sand pile is close to the factory standard, the test sand is taken out from the artificial sand pile, and the test sand is evenly divided into several parts, and the moisture content of the several parts of the test sand is quickly detected by the resistance test method, and the detection results are Φ1, Φ2...Φ n ;

[0010] Step six, the n value intervals A n ±λ are obtained by Φ n = [Φ n -λ, Φ n +λ], the value intervals of A1 to A n are overlapped, the interval with the most overlapping times is selected, and the midpoint value A 终 of the interval is taken, that is, A 终 is the actual moisture content of the test sand in step five.

[0011] Further, a test column is arranged on the central axis of the artificial sand pile, and a plurality of humidity sensors are arranged on the test column; the humidity sensors are connected with the detection terminal, and are used to feedback the humidity inside the artificial sand pile, so as to preliminarily judge the moisture content of the artificial sand pile, and further preliminarily judge the delivery time of the artificial sand pile.

[0012] Further, in steps one and five, the test sand just taken out from the artificial sand pile is first filtered and stirred in the sealed test bin, and then evenly divided after sufficient filtering and stirring, and the surface of the part in contact with the test sand in the sealed test bin is provided with a scratch-resistant hydrophobic layer.

[0013] Further, after the resistance test sand is evenly divided, the loose degree of each part of the resistance test sand after the division is adjusted by light pressure, so as to ensure that the loose degree of each part of the resistance test sand is consistent; at the same time, the loose degree of the resistance test sand after the division in steps one and five is also consistent after the light pressure adjustment.

[0014] Further, during the drying process of the artificial sand pile, the compaction force of the light pressure adjustment is experimentally tested, and the loose degree of the resistance test sand is selected when the moisture content is tested by the resistance test method and the test precision is the highest.

[0015] Further, the method of experimental testing is that a part of the test sand is taken out from the drying process of the artificial sand pile, and then the test sand is divided into a part of the drying test sand and a plurality of parts of the resistance test sand, and the plurality of parts of the resistance test sand reach different loose degrees under the action of different compaction forces; then the moisture content of the drying test sand is detected by the drying method, and the moisture content of the resistance test sand is detected by the resistance test method, and the moisture content of the drying test sand is α', and the moisture content of the resistance test sand is β1', β2'...β n '; the β i ' closest to α' is selected; the detected moisture content is βi The loose degree of the sand for resistance test in step one and step five is the standard loose degree, and the compaction force at this time is the standard compaction force;

[0016] The sand for resistance test in step one and step five is divided into several parts, and the moisture content of the sand is tested after the sand reaches the standard loose degree.

[0017] Further, the best distance between the probes in the resistance test method is determined by pre-experiment during the drying process of the manufactured sand pile. Meanwhile, the distance between the probes in the moisture content test of the divided sand for resistance test in step one and step five is the best distance.

[0018] Further, the method of pre-experiment is as follows: a part of the test sand is extracted from the drying process of the manufactured sand pile, and then the test sand is divided into a part of the drying test sand and several parts of the sand for resistance test. The several parts of the sand for resistance test are placed in the test slots with probes of different distances. Then the moisture content of the drying test sand is detected by the drying method, and the moisture content of the several parts of the sand for resistance test is detected by the resistance test method. The moisture content of the drying test sand is α'', and the moisture content of the sand for resistance test is β1'', β2''...β n ''. The β i '' closest to α'' is selected. The distance between the probes of the sand for resistance test with the moisture content of β i '' is the best distance.

[0019] The moisture content of the sand for resistance test in step one and step five is tested under the condition that the distance between the probes is the best distance.

[0020] Further, the distance between the probes can be set as 10 groups, i.e. 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm and 10mm. The best distance between the probes is selected by pre-experiment.

[0021] A manufactured sand moisture content control system for implementing the online detection method of the moisture content of manufactured sand, comprising a control module, a resistance test module, a drying test module and a data transmission module. The control module further comprises a calculation module for calculating the correction amount λ. The resistance test module and the drying test module are used to detect the moisture content of the test sand. The data transmission module is used to transmit the moisture content data detected by the resistance test module and the drying test module to the calculation module. The control module further comprises a correction detection module connected with the calculation module and used to output A 终 .

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The detection method of the present application introduces a correction amount λ, so that the actual water content in the machine-made sand falls within the range of Φ n ± λ; and by overlapping the n intervals A, the interval in which the actual water content is located is reduced, improving the detection accuracy of the water content; therefore, the present application improves the detection efficiency while improving the detection accuracy of the water content, eliminating the situation that the efficiency and accuracy cannot be guaranteed at the same time in the past detection. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0025] Figure 1 The figure is a schematic diagram of the overall structure of the control system used in the present application.

[0026] Among them: 1, control module; 2, calculation module; 3, correction detection module; 4, resistance test module; 5, drying test module; 6, data transmission module. DETAILED DESCRIPTION

[0027] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the following will combine the drawings and the preferred embodiments to specifically describe the specific embodiments, structures, features and effects of the present application.

[0028] Embodiment: An online detection method for water content of machine-made sand, comprising the following steps:

[0029] Step one, a test sand is extracted from the machine-made sand drying process, and then the test sand is divided into a drying test sand and a plurality of resistance test sands;

[0030] Step two, the water content of the drying test sand is detected by drying method, and the water content of the plurality of resistance test sands is detected by resistance test method; let the water content of the drying test sand be α, and the water content of the resistance test sand be β1, β2, β3, β4... β n ;

[0031] Step three, β1 to β n are respectively subtracted by α, and the absolute values γ1 to γ n of the results are taken, and γ1 to γ nThere are j values ​​with a difference greater than 0.5%. Among them, since the accuracy of the resistance test method is ±0.5%, a difference greater than 0.5% indicates that the sand used for resistance testing has poor contact or short circuit during the test, or is at the end of the measurement accuracy range (large error). These values ​​should be discarded to improve the overall detection accuracy of the test method.

[0032] Step 4: Let the correction amount λ be the average value of the remaining γ values, that is... Since the value of β will fluctuate around the value of α, λ will be less than 0.5%, and the value of the correction amount λ will also be determined at this time.

[0033] Step 5: When the moisture content of the manufactured sand pile reaches near the factory standard, remove the test sand from the pile and divide it into several equal portions. Use a resistance test to quickly determine the moisture content of each portion of test sand, and record the results as Φ1, Φ2...Φ n ;

[0034] Step Six: Through Φ n ±λ yields n value intervals A n =[Φ n -λ, Φ n +λ], from A1 to A n If the value intervals overlap, select the interval with the most overlaps and take the midpoint value A of that interval. 终 A 终 This refers to the actual moisture content of the sand used in step five; the actual moisture content will fall within Φ. n Within the range of ±λ, since λ is less than 0.5%, the detection accuracy of moisture content is improved. At this point, the detection error of the detection method in this invention is between that of the drying method and the resistance testing method, and is more accurate than the resistance testing method. Furthermore, by overlapping n intervals A, the range containing the actual moisture content is further narrowed, and by taking the midpoint of the interval with the most overlaps as the actual moisture content value, the detection accuracy is further improved. In the detection process, the resistance testing method is used; therefore, this invention improves both detection efficiency and the detection accuracy of moisture content using the resistance testing method, eliminating the situation where efficiency and accuracy could not be guaranteed simultaneously in previous detection methods. In addition, in step five, Φ is removed... n The maximum and minimum values ​​in the data can reduce detection errors. This invention determines the correction amount λ during the drying process of the manufactured sand pile, so that the online detection method of this invention can be directly used after drying, thereby saving detection time.

[0035] And in the present application, the middle axis of the machine-made sand pile is provided with a test column, and a plurality of humidity sensors are arranged on the test column; the humidity sensors are connected with a detection terminal, and are used for feeding back the humidity inside the machine-made sand pile, so as to facilitate the preliminary judgment of the water content of the machine-made sand pile, and further facilitate the preliminary judgment of the delivery time of the machine-made sand pile; it is convenient for the tester to measure the machine-made sand in time; and in the above steps one and five, the test sand taken out from the machine-made sand pile is first filtered and stirred in the sealed test bin, so that the water content of the test sand is more uniform, and the impurities in the test sand are filtered out at the same time, the test sand is evenly divided after being fully filtered and stirred, and the surface of the part in the sealed test bin in contact with the test sand is provided with a scratch-proof hydrophobic layer, so as to prevent the water in the machine-made sand from remaining on the stirring mechanism; the detection accuracy is improved.

[0036] Because the contact area between particles is reduced when the machine-made sand is too loose, more gap resistance will be generated in the current path, thereby forming a non-uniform electric field; this unstable contact will significantly increase the measurement error, thereby affecting the test accuracy of the resistance test method; therefore, in the present application, the resistance test sand is lightly pressed after being evenly divided, so as to ensure that the loose degree of each part of the resistance test sand is consistent; at the same time, the loose degree of the resistance test sand after being evenly divided in steps one and five is also consistent after being lightly pressed; thereby improving the test accuracy of the resistance test method; in order to find the most suitable loose degree of the machine-made sand for the resistance test method; therefore, in the detection method in the present application, the compaction force of the light pressure adjustment is tested during the drying process of the machine-made sand pile, so as to select the loose degree of the resistance test sand when the test accuracy is the highest when testing the water content by the resistance test method.

[0037] The specific experimental test method is as follows: a part of test sand is taken out from the machine-made sand pile during the drying process, and then the test sand is divided into a part of drying test sand and a plurality of parts of resistance test sand, the plurality of parts of resistance test sand reach different loose degrees under the action of different compaction forces; then the water content of the drying test sand is detected by the drying method, and the water content of the plurality of parts of resistance test sand is detected by the resistance test method, the water content of the drying test sand is α', and the water content of the resistance test sand is β1', β2'... βn'; the β closest to α' is selected; the water content of the resistance test sand is β n '; the water content of the resistance test sand is β i '; the water content of the resistance test sand is β iThe loose degree of the sand for resistance testing in the step one is the standard loose degree, and the compaction force at this time is the standard compaction force, so that the loose degree is consistent and the loose degree is in the best detection state in the detection process of the resistance testing method, the detection precision is improved, and in addition, the test sand can be extracted for multiple experiments during the drying process of the manufactured sand pile, and the average value is taken, so that the best standard compaction force and standard loose degree are obtained; and the resistance testing sand is divided in the step one and the step five, and the water content is tested after the standard loose degree is reached, so that the test precision of the whole test method is provided.

[0038] In the process of using the resistance testing method, if the probe spacing is too small, the current will be concentrated in the local area, and the overall conductivity of the manufactured sand cannot be reflected; if the spacing is too large, the current path is lengthened, the risk of electric field distortion is increased, and the resistivity calculation result is deviated; in addition, if the probe spacing is too small, the contact pressure is insufficient, which may cause poor contact between the probe and the sand particles, and increase the contact resistance; if the spacing is too large, higher pressure is needed to stabilize the contact, which may damage the sand body structure; therefore, the best spacing of the probe is also an important parameter for improving the test precision of the resistance testing method; therefore, in the drying process of the manufactured sand pile, the best spacing of the probe in the resistance testing method is determined through pre-experiment, and the spacing of the probe is the best spacing when the water content of the resistance testing sand is tested in the step one and the step five, so as to improve the test precision of the resistance testing method.

[0039] The method of the pre-experiment is as follows: in the drying process of the manufactured sand pile, a test sand is extracted from the drying process of the manufactured sand pile, then the test sand is divided into a drying test sand and a plurality of resistance testing sands, the plurality of resistance testing sands are placed in test slots provided with probes with different spacings; then the water content of the drying test sand is detected by the drying method, and the water content of the plurality of resistance testing sands is detected by the resistance testing method, the water content of the drying test sand is α'', the water content of the resistance testing sand is β1'', β2''...β n ''; the β i '' closest to α'' is selected; the probe spacing of the resistance testing sand with the water content of β i '' is the best spacing; so that the spacing of the probe is in the best spacing state in the detection process of the resistance testing method, the detection precision is improved, and in addition, the test sand can be extracted for multiple experiments during the drying process of the manufactured sand pile, and the average value is taken, so that the best spacing is obtained; and the resistance testing sand is divided in the step one and the step five, and the water content is tested after the standard loose degree is reached, so that the test precision of the whole test method is improved.

[0040] In addition, in combination with the bulk density of the sand for resistance testing and the volume in actual testing (because the number of detection samples is large, the volume of each sample is generally small), the distance of the general probe is within 5-10 mm, therefore, the distance of the probe is set as 10 groups in the pre-experiment, that is, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm and 10 mm, and the optimal distance of the probe is selected through the pre-experiment.

[0041] In the above detection method, the experimental test of the bulk density, the pre-experiment of the optimal distance and the measurement of the correction amount λ are all carried out in the drying process of the machine-made sand pile, therefore, when the moisture content of the machine-made sand needs to be detected, it can be directly detected, and the detection efficiency of the moisture content at the factory is greatly improved.

[0042] Please refer to Figure 1 ; a machine-made sand moisture content control system for implementing the machine-made sand moisture content online detection method, comprising a control module 1, a resistance testing module 4, a drying testing module 5 and a data transmission module 6, the inside of the control module 1 is further provided with a calculation module 2 for calculating the correction amount λ, the resistance testing module 4 and the drying testing module 5 are both used for detecting the moisture content of the testing sand, the data transmission module 6 is used for transmitting the moisture content data detected by the resistance testing module 4 and the drying testing module 5 to the calculation module 2, and the inside of the control module 1 is further provided with a correction detection module 3 connected with the calculation module 2 and used for outputting A 终 ; therefore, in the drying process of the machine-made sand pile, only one portion of testing sand needs to be taken out from the machine-made sand, and then the testing sand is divided into several portions, the moisture content is measured through the resistance testing module 4 and the drying testing module 5, the data measured by the resistance testing module 4 and the drying testing module 5 is transmitted to the calculation module 2 for calculating the correction amount λ, when the moisture content of the machine-made sand pile at the factory needs to be tested, only one portion of testing sand needs to be taken out from the machine-made sand pile, and then the testing sand is divided into several portions, the correction detection module 3 detects the moisture content of the several portions of testing sand after obtaining the correction amount λ, and finally A 终 is obtained, A 终 is the actual moisture content of the testing sand; therefore, the detection error of the detection method in the application is greater than that of the resistance testing method; and the resistance testing method is adopted in the detection process, therefore, the detection efficiency is improved, the detection precision of the moisture content detected by the resistance testing method is improved, and the situation that the efficiency and the precision cannot be ensured at the same time in the previous detection is eliminated.

[0043] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can also be present. As used herein, the terms "above," "below," "left," "right," "front," "back," and the like merely describe the orientation in accordance with the drawings under discussion and are not intended to limit the position of the described elements.

[0044] The above descriptions are only the preferred embodiments of the present application, not intended to limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical contents to make equivalent embodiments with equivalent changes, but as long as it does not deviate from the technical solution of the present application, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application shall be within the scope of the technical solution of the present application.

Claims

1. A method for on-line detection of moisture content of manufactured sand, characterized in that, Comprise the following steps: Step one, from the mechanism of sand pile drying process to extract a test sand, and then the test sand into a drying test sand and several resistance test sand; Step two, detect the moisture content of the sand for drying test by drying method, and detect the moisture content of several portions of sand for resistance test by resistance test method; let the moisture content of the sand for drying test be a, and the moisture content of the sand for resistance test be β1, β2, β3, β4... β n ; Step three, subtracting a from each of β1 to β n and taking the absolute value of the result γ1 to γ n , respectively. Step four, removing j of the differences greater than 0.5% from γ1 to γ n . Step four, set the correction amount λ as the average of the remaining γ values, i.e. ; Step five, when the moisture content of the manufactured sand pile is close to the factory standard, the test sand is taken out from the manufactured sand pile, and the test sand is evenly divided into several parts, and the moisture content of the several parts of the test sand is rapidly detected by the resistance test method, and the detection results are Φ1, Φ2...Φ n ; Step Six: Through Φ n ± We obtain n value intervals A n =[Φ n - , Φ n + ], transfer A1 to A n If the value intervals overlap, select the interval with the most overlaps and take the midpoint value A of that interval. 终 A 终 This refers to the actual moisture content of the sand used in step five of the test. When the moisture content of the manufactured sand pile at the factory is required to be tested, only a portion of the test sand is taken out from the manufactured sand pile, and then the test sand is divided into several portions, and the moisture content of the several portions of test sand is detected on the basis of obtaining the correction amount λ to finally obtain A 终 , A 终 is the actual moisture content of the test sand; the introduction of the correction amount λ makes the actual moisture content in the manufactured sand pile fall within the range of Φn±λ; and through the overlap of the n intervals A, the interval where the actual moisture content is located is narrowed down, and the detection accuracy of the moisture content is improved.

2. The method for on-line detection of moisture content of manufactured sand according to claim 1, characterized in that: The test column is arranged on the central axis of the artificial sand pile, and a plurality of humidity sensors are arranged on the test column; the humidity sensors are connected with the detection terminal, and are used for feeding back the humidity in the artificial sand pile, so as to preliminarily judge the water content of the artificial sand pile, and then preliminarily judge the delivery time of the artificial sand pile.

3. The method for on-line detection of moisture content of manufactured sand according to claim 1, characterized in that: In step one and step five, the test sand just taken out from the artificial sand pile is first filtered and stirred in the sealed test bin, and then evenly divided after sufficient filtering and stirring, and the surface of the part in contact with the test sand in the sealed test bin is provided with a scratch-resistant hydrophobic layer.

4. The method according to claim 3, characterized in that: After the resistance test sand is evenly divided, the loose degree of each part of the resistance test sand is adjusted by light pressure, so as to ensure that the loose degree of each part of the resistance test sand is consistent; at the same time, the loose degree of the resistance test sand after being evenly divided in step one and step five is also kept consistent after light pressure adjustment.

5. The method according to claim 4, wherein: During the drying process of the artificial sand pile, the compaction force of the light pressure adjustment is tested, and the loose degree of the resistance test sand is selected when the water content is tested by the resistance test method and the test precision is the highest.

6. The method according to claim 5, wherein: The method for experimental testing is that a test sand is drawn from the stockpile of the manufactured sand during the drying process, then the test sand is divided into a dried test sand and a plurality of resistance test sands, the plurality of resistance test sands reach different loose degrees under different compaction forces; then the moisture content of the dried test sand is detected by the drying method, the moisture contents of the plurality of resistance test sands are respectively detected by the resistance test method, the moisture content of the dried test sand is α', the moisture contents of the resistance test sands are β1', β2'...β n ' is selected as the standard loose degree, and the compaction force at this time is taken as the standard compaction force. i i ' is taken as the standard loose degree, and the compaction force at this time is taken as the standard compaction force.​ The resistance test sand after being evenly divided in step one and step five is tested for water content only after reaching the standard loose degree.

7. The method according to claim 3, wherein: During the drying process of the artificial sand pile, the best distance of the probe in the resistance test method is determined through pre-experiment, and at the same time, the distance of the probe is the best distance when the water content of the resistance test sand after being evenly divided in step one and step five is tested.

8. The method according to claim 7, characterized in that: The preliminary experiment method was as follows: a sample of test sand was extracted from the dried sand pile. This sample was then divided into a dried test sand sample and several resistance test sand samples. The resistance test sand samples were placed in test chambers with probes at different spacings. The moisture content of the dried test sand was then measured using a drying method, and the moisture content of each resistance test sand sample was measured using a resistance test method. Let the moisture content of the dried test sand be α'', and the moisture content of the resistance test sand be β1'', β2'', ..., β... n ''; Select the β closest to α'' i ''; to detect a water content of β i The probe spacing for the resistance test sand was optimal; the moisture content of the resistance test sand, after being evenly divided in steps one and five, was tested under the condition that the probe spacing was optimal.

9. A mechanism sand moisture content control system for the implementation of the detection method according to any one of claims 1-8, characterized by: The control module, the resistance test module, the drying test module and the data transmission module are included, the control module is internally provided with a calculation module for calculating the correction amount λ, the resistance test module and the drying test module are both used for detecting the water content of the test sand, the data transmission module is used for transmitting the water content data detected by the resistance test module and the drying test module to the calculation module, and the control module is internally provided with a correction detection module connected with the calculation module and used for outputting A 终 the correction amount λ.

Images